plan 436Construction & Implementation of Water System in Nueva America, Bolivia

Summary

This project will provide access to safe, reliable water to 40 families in the village of Nueva America. Project includes water system, formation of training of local water committee and community water & hygiene workshops.

Background

The community Nueva America is located in District 1 of 4 de Marzo of the Municipality of Santa Rosa, approximately 50 kilometers from the capitol city Santa Rosa. The community has a small school that was constructed approximately 6 years ago. Approximately 20 students from first to sixth grade attend the school.

Five years ago Proasu Jica, a program under the state government, perforated a water well in the village. The well depth is 122 meters deep with the static water level at 13 meters. The community often use tubes to access water from the narrow well. This method does not allow extraction of a lot of water and does not work year round. With no functioning water well, the villagers worked together to excavate their own shallow well. This has been the village’s main water source. Some families also turn to a small stream nearby the village to get water, particularly during the rainy season. Current water supply problems include the time required to retrieve the water each day as well as the quality of the water. It takes women and children many trips each day with buckets, consuming their time. Also, the clean water becomes contaminated as it is being carried to their homes. The water situation has serious consequences on village health and high rates of diarrhea.

For years the village has been soliciting the local municipality for a water system. One villager says, “We've tried everything. We even built our own water tank. It doesn't work now. People here live like animals, drinking water directly from the river.” (Sr. Pablo Perez, Community Member)

Location

Nueva America, Obispo Santistevan in the Department of Santa Cruz , Bolivia

Attachments

  • CARTA_SA...
  • descript...
  • 01-SANTA...
  • LAMINA_N...
  • Plastifo...
  • Guarente...
  • image002...
  • Hydropne...
  • Budget_W...
  • Options_...

Focus

Primary Focus: Water - Community
Secondary Focus: Hygiene Education

People Getting Safe Drinking Water: 200

This project will serve 200 people that live in the village permanently, including 40 families (70 men, 60 women, 45 are children between the ages of 6 and 16, and 25 children between 0 and 5).

According to statistics provided by the municipality 60 families live in Nueva America. Based on our needs assessment we learned that 26 homes are in close proximity to one another where families live permanently. Of these 26 homes, numerous have multiple families living on one piece of property or in one home. Considering this, approximately 40 families will receive water.

The project includes public water points for more dispersed families. The water committee will determine will determine water tariffs and fines to control the public points.

School Children Getting Water: 20

45 are children between the ages of 6 and 16, and 25 children between 0 and 5. Only 20 students attend the village school. The rest do not attend school or attend a school outside the village. (Source: local village school)

People Getting Sanitation: 0

People Getting Other Benefits: 200

Water Committee (6 people)
At the start of the project the community will elect 6 people to form a water committee. The committee will travel to the city of Cochabamba to receive technical training directly from Plastiforte, the manufacturer of the hydroneumatic tower, regarding the installation and maintenance of the system. They will participate in continued training throughout the course of the project regarding administration and leadership.

Water & Hygiene Community Workshops (40 families)
A minimum of one member from community will participate in a series of eight workshops intended to strengthen knowledge related to water and sanitation knowledge and improve hygiene habits. Themes of the workshop include: Importance of Safe Drinking Water, Water-Related illnesses, Sources of Contamination, Personal Hygiene, Food Hygiene, Hygiene in the Home, Garbage & Recycling, and Sanitation.

Children’s Education Program (20 children, 2 teachers)
The project will partner with the village school to work alongside teachers and students, with the objective of teaching students about the themes in the community workshops, while participating in specific activities continually that aim to create healthy habits.

Start Date: 2013-03-01

Completion Date: 2013-10-31

Technology Used:

Approach: This program is a comprehensive, community-effort to engage families to make improvements to their health and well-being by improving the water situation in their community. People of Nueva America will elect six villagers to serve on a water committee. Members will be trained in: Structure, Role, Responsibilities, and Organization of the Water Committee; Financial Management; Mobilizing the Village; Water Quality; Hygiene; and Technical Operation and Management of the Water System. Water committee members will travel to the city of Cochabamba to participate in technical training from Plastiforte, the manufacturer of the Hydroneaumatic system, the water technology used in this project. This process will ensure that all knowledge about the water system remains within the local village. The water committee will ultimately promote community lead, ownership and transparency.

During the course of the project members of committee will also learn how to administer their system and teach healthy habits to their own community. Throughout this process community members will recognize themselves as capable of improving their situation without reliance on outside assistance. In doing so, knowledge will be maintained in the village so that the water project can be sustainable.

The project includes interactive, fun workshops and activities related to water, hygiene and sanitation offered to both children in the community and the community at large. The education program will focus on hygienic habits involving hand-washing, food, cooking utensils, water, and sanitation. Participants, for example, will not simply be asked to memorize steps in hand washing or methods to eliminate excreta. Instead this project seeks to work with the community to develop activities that encourage people to think about why hand washing is important or how and why contamination can spread throughout a community and the consequences it has on one’s health. Participants will develop strategies and methods to care for their own well being, the environment and the community at large.

Technology: The water technology used includes a hydropneumatic tower. The hydropneumatic tower essentially replaces expensive elevated tanks that are traditionally used in water systems with perforated wells. The Hydropneumatic Tower will connect to a water distribution system that distributes the water to 26 households, 2 public points and the village school. Each family will be responsible for assisting in the manual labor necessary to install the water system and financially contribute to the cost of materials necessary for their own domestic connection.

The technology is similar to an elevated water storage tank, but much smaller in size and typical in demand. The tower operates essentially by keeping a column air in the HDPE pipe which is 6 meters tall. The pressure vessel contains water with a pressurized air space to provide the pressure for the system. With water demand, water flows from the vessel, increasing the air space as well as decreasing air pressure. This lower pressure signals the pump to start. The pump meets the demand with the excess volume backing up in the pressure vessel. This decreases the air space and increases the pressure once again. When the upper level is reached, the pump shuts off. These systems are ideal for a rural water system that has a limited service area.

Some advantages of the Hydropneumatic Tower include: reduced cost (no need to construct expensive elevated tanks), easy installation, automatic operation, optimization of the electrical power consumption in the operation of the pump, and a 20-year guarantee.

The distribution system will use HDPE Pipes. HDPE pipe is recognized in the industry for its zero leak rate, high performance, and long life expectancy. In addition, HDPE is more flexible, nontoxic and has greater resistance to impact. Because the piping comes in long roles of 50m to 100m, the installation process is faster and easier. It also makes it easier to transport to the village.

Phases:

This project is implemented in only one phase, with the following components:
- Community Organization
- Formation of local water committee
- Training
o Community water & higiene workshops
o Water committee workshops
o Construction & implementation

Community Organization:

The community of Nueva America is motivated and organized. They have a directory committee consisting of a community President (referred to as the “OTB”), Vice President, Treasurer, Secretary and Communication Officer. The directory committee has been working with the municipality to secure a water project for their community.

Each family owns their own piece of the land, although many extended families live on the same piece of property. The water well sits on public area that is owned by the local municipality. The municipality is responsible for elaborating water and sanitation projects.

The community is in full agreement of financially contributing to the installation of each domestic water connection. They also agreed to attend workshops and participate in activities.

Government Interaction:

This project utilizes a water well perforated by Proasu Jica, a program operating under the state government of Santa Cruz. The municipality of Santa Rosa will partner with Etta Projects to implement the water project. Members from the Department of Water & Sanitation will attend the training sessions in Cochabamba and will also contribute funding towards the hydropneumatic tower and the distribution system.

Ancillary activities:

All water committee members will learn skills in plumbing as well as administrative skills.

Other Issues:

Currently in Bolivia local municipalities are responsible for the provision of water and sanitation. Unfortunately they often do not have the necessary resources to reach many of the rural villages to implement this type of project. We’ve learned that when different sectors join forces communities like Nueva America can access clean, safe drinking water.

Maintenance Revenue:

The Project is designed with built-in long term sustainability. The process of ensuring the sustainability of the water system includes:
1. The community will develop ownership of the water system, predominantly due to their own contribution of manual labor and resources. The financial contribution of each family gives the community a larger stake in the sustainability of the water system. It will also encourage families to maintain and repair the water system.
2. The community will manage the water system and continually pay for water usage. Families will make monthly payments based on the quantity of water usage. Upon completion of the system the local water committee will organize a series of water tariff payment workshops. The workshops will focus on the importance of each family to pay their monthly tariff regularly. A constant funding stream will not only maintain the feasibility of the water system, but also provide incentive and ability to ensure that the Water Committee will continue to offer safe drinking water to the village.
3. The water committees will have representation from major stakeholder groups, including women representation, Women’s participation will bring a unique and important perspective regarding water and hygiene education.
4. The village school will be given special attention to ensure that students have a dependable, safe drinking water supply both at home and in school.

4. The specific technology used comes with a guarantee for 20 years from the manufacturer. It is appropriate technology for the village to meet its demand of water.
5. The project is a partnership from organizations of different sectors, including Etta Projects, the local municipality, the state government and the local village.
6. Metrics of success will be developed with the stakeholder groups and information will be shared regularly with all stakeholders.

The maintenance of the system is fairly minimum. The traducer needs to be replaced every 3 to 5 years, and costs $35 US. The traducer can be monitored and replaced when maintaining the pump. Annual operating expenses include: electricity, system accessories, and other tools and administrative materials, totaling $800 per year (Source: Plastiforte). A Water Engineer and expert from the U.S. Joe Sesil, member, recently visited Etta Projects in Bolivia and researched the technology. He wrote, “the hydropneumatic tower is a solid system, with minimum maintenance and few moving parts that could go wrong.”

Maintenance Cost: $800

Metrics:

The water system will be monitored monthly throughout the eight months of the project. Once completed, Etta Projects will continue to monitor the project quarterly for the following three years. Tracking will include tools such as household interviews, data from lack health center and direct observation. The following meters will be considered:
• availability of clean water
• quality of water (water samples)
• beliefs and practices related to clean water
• hygiene habits
• incidence of diarrhea
• satisfaction of the water system
• administration of the water system (role of water committee)
o transparency
o income-receipts and resources
o correct maintenance of water system
o enforcement of policies

Cost: $20,542

See attachment

Co Funding Amount: $5,571

Contribution from the Municipality of Santa Rosa. Includes 50% of the cost of the water tower and water distribution pipes and 25% of transportation cost of water system from Cochabamba to Nueva America. Also includes cost of 1 staff member to travel to Cochabamba to attend technical training.

Community Contribution Amount: $3,699

Each family will contribute the funding to cover the cost of the materials to make a domestic connection from the water distribution system to their home. This includes 6 meters of piping, a faucet, and a water meter. Families will also contribute manual labor needed to install the system.

Fund Requested: $12,000

Attachments

  • CARTA_SA...
  • descript...
  • 01-SANTA...
  • LAMINA_N...
  • Plastifo...
  • Guarente...
  • image002...
  • Hydropne...
  • Budget_W...
  • Options_...
  • 1 participant | show more

    Details on the technology . Also can't open the budget

    Gilles Corcos of Agua Para la Vida (APLV)

    This is an interesting new technology and I would like to understand it better. First while I have no great conceptual problem with your air tower , ( I believe it is a manometer with a feed-back). I am curious about your and your pump cycling frequency which you say should not exceed once a week. With the population you indicat...

    This is an interesting new technology and I would like to understand it better.
    First while I have no great conceptual problem with your air tower , ( I believe it is a manometer with a feed-back). I am curious about your and your pump cycling frequency which you say should not exceed once a week.
    With the population you indicate and even neglecting a growth projection (which should be included), and assuming 50 liters per inhabitant per day the weekly consumption amounts to 70 cubic meters . It seems to me that the with its bladder attachment should be comfortably larger than that volume, probably 2 or 3 times that much or 140 to 210 cubic meters. From what you say I think I understand that you take the conduction line and its tree (the distribution network) as part of the tank. If so you might tell us the capacity of the piping to the various water points. What pipe inner diameters and pipe lengths? If for instance I assume for lack of information and to simplify, a pipe inner diameter of 8cm, to hold 70cubic meters of water, it would take an impossible number of kms of piping. Which suggests that the tank itself needs to have very nearly the capacity of 140 to 210 cubic meters. But such a tank which has to hold a substantial pressure ( you mention several atmospheres) is tricky and expensive to build or expensive to buy and ship. Might you have mistaken the cycling frequency of the pump? Or am I all wet?
    By the way It could easily cycle twice a day without affecting the pump life. Still the tank cost would be substantial.
    I might have had some indication of the network from your budget but I was not able to open the budget Excel sheet provided as an attachment. Perhaps you can send it in a more convenient form. I t does not need to be compressed.
    Another detail: I assume that you have made the tests which ensure that the well has the capacity in all seasons to provide enough village water?

    Finally while this is certainly an innovative approach I am concerned by the maintenance problem of the installation and your confidence in the village ability to take care of it.
    Cordially,
    Gilles

  • 2 participants | show more

    System design

    Lynn Roberts of Agua Para La Salud (APLS)

    In reviewing this applications water system design I do not see a distribution tank that serves the homes. Is the terrain such that a tank cannot be installed above the village to reduce the on/off events of the well pump. As designed it appears that the pump will cycle quite frequently with household use, instead of a long run time to fil...

    In reviewing this applications water system design I do not see a distribution tank that serves the homes. Is the terrain such that a tank cannot be installed above the village to reduce the on/off events of the well pump. As designed it appears that the pump will cycle quite frequently with household use, instead of a long run time to fill a distribution tank during night hour and peak electricity power.

    Please explain what would be the process of repair if the pump should cease to function. At what distance is the nearest repair source ( person or business)and what would it cost to extract the pump ; repair the pump; reinstall the pump; and who would pay for this process.

    • Katie Chandler of Etta Projects

      Hi Lynn and Michael, Thank you both very much for taking the time to review the project and for your comments and questions. I’m happy to answer your concerns regarding the water system. The community is responsible for fixing the pump or soliciting the necessary professional. The nearest repair shop is in Santa Cruz, which is ap...

      Hi Lynn and Michael,

      Thank you both very much for taking the time to review the project and for your comments and questions. I’m happy to answer your concerns regarding the water system.

      The community is responsible for fixing the pump or soliciting the necessary professional. The nearest repair shop is in Santa Cruz, which is approximately 200 kilometers from the village or 4 hours of traveling. The water committee is trained to take out the water pump and replace the motor. The removal of the water pump should take about 2 hours. The most expensive maintenance of the pump is replacing the motor. This cost is $380, but should only need to be done every 5+ years.

      The water tower has a guarantee of 20 years; Plastiforte will cover any repair expenses. The water committee in the village is trained by Plastiforte and have the contacts for this company.

      Each household connection will include the installation of a water meter. We try to encourage communities to use water meters in order to motivate water conservation. Ultimately it is the community’s decision to purchase the meters since each family is responsible for paying for their own meter. Nueva America voted to purchase the meters. The cost of each meter is $58, which is included in the family’s contribution item of the budget. The remaining $39 will be used to purchase the rest of the kit for the domestic connection. Families have been saving towards their contribution and have agreed to contribute this funding. Etta Projects sets up payment plan when necessary to allow participation of all families.

      The system does not include a storage tank, but the pump does not need to be turned on each time the tap is opened. With this tower the pump has very little performance and only needs to occasionally activate to pressurize the Tower. In other words, the pumps only function is to control the pressure, so that the tower can distribute the water. The use of the pump depends on the excessive consumption of water. In installations similar to Nueva America, the pump runs less than 1 time a week. The tower operates essentially by keeping a column of air in the HDPE pipe which is 6 meter tall, approximately 20 feet (so low maintenance). Therefore, to set up, you just run your pump until you fill the system and the tower up until the pressure in the tower pipe raises to 3 bars (about 45 psi - or about 100 feet of pressure) and the pump kicks off. The pump will remain off and the system will continue to maintain pressures (above 2 bars - 30 psi-or 67 feet). The pressure will remain unless there is excessive use of water throughout the community which is when the pump will kick back on. The only really mechanical part of the tower is the pressure transducer which measures the pressures to send a signal to turn off and on the pump. The pneumatic tower works on a similar principle as the tower works on a similar principle, but does not have to have the membrane blatter replaced (therefore it should have a much longer life (they say 20 to 30 years) with minimal maintenance. The cost to replace the transducer is $35 US, and should only need to be done every 5 years.

      The pump will be hooked up to its own meter measuring the use of electricity. We anticipate that the average monthly electrical cost will be 200 Bs, or approximately $29. The minimum tariff per family is $2.20, with 30+ households the village will collect $66 per month leaving over 44% of the monthly income to be saved for maintenance and repairs to the water system.

      I hope this helps clarify any doubt. Please let me know if you have any other questions or concerns.

      Thanks much,
      Katie

  • 2 participants | show more

    questions

    Chitra Chaudhuri of Gram Vikas

    Hi Katie, Your explanations have been helpful to understand the system better. We would also like to understand whether Etta projects have implemented such a system before? If not what made you go for this technology? Since the system requires electricity continously, how does it work in the rural areas there? In India it would be ve...

    Hi Katie,

    Your explanations have been helpful to understand the system better. We would also like to understand whether Etta projects have implemented such a system before? If not what made you go for this technology?

    Since the system requires electricity continously, how does it work in the rural areas there? In India it would be very difficult to set up such a technology in rural areas with frequent power outages.

    Thirdly, since the community has not been used to such a continous water supply system, how will ETTa projects ensure that the management of the system will be done after training is received?

    thanks
    chitra
    gram vikas

    • Joe Sesil of Team Blue

      Hello all, I apologize for my late reference on comments regarding this Plastiforte pneumatic tower system and the associated projects. I had the opportunity to visit four of the various sites that Etta project have installed wells and water distribution systems along with the chance to go to the Plastiforte manufacturing plant to see t...

      Hello all,

      I apologize for my late reference on comments regarding this Plastiforte pneumatic tower system and the associated projects. I had the opportunity to visit four of the various sites that Etta project have installed wells and water distribution systems along with the chance to go to the Plastiforte manufacturing plant to see the product in both manufacturing and in use. Katie provided an excellent summary of it all above, and I don't know if I could add much more regarding it, but if you have other questions about the equipment I might be able to help and or the Plastiforte rep. Gustavo Heredia gheredia@grupoforte.net - I also visited the manufacture with John Rodriguez from Water For People Bolivia and he has a good understanding of the system and the site as well. The system is in use in many location in and around Cochabamba and form my research the products has been quick successful in practice in the field.

      For quick reference on your specific question above Gram, the tower itself does not actually require electricity, it runs off the pressure / hydraulics from the pump discharge. The pump however does require electricity and the site has an electric supply source close to the pump location. The other four sites that had a chance all had electric pumps and were tied to the electric power server, so it appears to be a pretty regular service and way of using pumps in the area.

      Katie or some of the people from the community can answer your last question best, but from my experience from the sites I visited, Etta Project had teamed with the community closely in all facilities of planning, installing and managing the well. They had in country staff who work closely and on a regular basis with the communities. That in county staff works with the community both on general good hygiene and health as well as maintenance and operations. They have a "water board" or committee or team in each village responsible for the system, water use, maintenance and general good hygiene. From the sites I visited it appeared to be working well and local members were quite proud to be on the board/committee/team. I would have to assume the same process would be in place here.

      I hope of some help. - And again I apologize for my lateness in responding.

      Thanks all!!

      Joe

  • 2 participants | show more

    Still the technology

    Gilles Corcos of Agua Para la Vida (APLV)

    I have to return to the observation that Lynn made early to the effect that the piping system cannot be considered an adequate reserve for a volume of water. If I understand his thought I agree with him. My understanding is that if the vertical air-water column is directly connected to the beginning of the conduction line piping, the cap...

    I have to return to the observation that Lynn made early to the effect that the piping system cannot be considered an adequate reserve for a volume of water. If I understand his thought I agree with him. My understanding is that if the vertical air-water column is directly connected to the beginning of the conduction line piping, the capacity of the system without starting the pump is only a fraction (1/2, 1/3?) of the vertical column volume. The reason is that as water is drawn at the other end, water being incompressible and plastic pipe only a little less so, nearly the same amount of water will be drawn from the water column- the difference being the swelling under pressure of the plastic pipe of the conduction line which will act weakly as a bladder. So almost as soon as an amount of water comparable with a fraction of the column volume is drawn from the faucets, the pressure in the column will fall enough to start the pump which will operate almost continuously if its flow rate is initially less than the rate of withdrawal of the water at the end of the pipe or it will go on and off continuously if the pump flow rate is superior to the rate of use of the water.

    Given the type of plastic used for the conduction line, the bladder effect of the piping itself can be calculated but that I believe can only result in a capacity which is a tiny fraction of the piping volume.

    again if I'm wrong please explain.

    Gilles

    • Lynn Roberts of Agua Para La Salud (APLS)

      You are correct--- what you displace is what shows up at the other end of the tube whether it is in the brake system of you car ; the straw of your milk shake or a water system.

      You are correct--- what you displace is what shows up at the other end of the tube whether it is in the brake system of you car ; the straw of your milk shake or a water system.

  • 2 participants | show more

    How is individual home water use measured

    Michael Williamson of Bank-On-Rain

    In the application, the tariff paid by each household is to be determined by water usage. Is the connection plumbing to each house metered? This would seem to be very expensive and no line items appear in the budget for this. Along the lines of the question by Lynn Roberts about the pump cycling, without a storage tank it would seem t...

    In the application, the tariff paid by each household is to be determined by water usage. Is the connection plumbing to each house metered? This would seem to be very expensive and no line items appear in the budget for this.

    Along the lines of the question by Lynn Roberts about the pump cycling, without a storage tank it would seem that the pump must cycle many times each day (every time a tap is opened). The electrical power required of a motor is greatest at start-up, many times the electrical power required for running the motor. A pump constantly starting and stopping will use much more power and therefore increasing the cost of electricity. How is the electricity use charged, by metered use or a flat rate?

    Thanks

    • Katie Chandler of Etta Projects

      Hi Michael, I just wanted to let you know I responded to yours questions in the same post I did after Lynn's comments. I wanted to make certain you received it as well. Please let me know if you need any additional clarifications. Thanks again! Katie

      Hi Michael,

      I just wanted to let you know I responded to yours questions in the same post I did after Lynn's comments. I wanted to make certain you received it as well. Please let me know if you need any additional clarifications.

      Thanks again!

      Katie

      • Michael Williamson of Bank-On-Rain

        Got it, thanks. Still a bit uncertain about the time between cycles of the pump unless the tower has sufficient volume to act as a temporatry storage tank. Do you know what the tower capacity is? Mike

        Got it, thanks. Still a bit uncertain about the time between cycles of the pump unless the tower has sufficient volume to act as a temporatry storage tank. Do you know what the tower capacity is?

        Mike

        • Katie Chandler of Etta Projects

          Hi Mike, I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for control...

          Hi Mike,

          I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for controlling the pump (similar to a storage tank or elevated tank by holding the pressure). When the pressure drops below a certain pressure the pump kicks on – (in the place of an elevated tank it fills to a certain elevation which is a certain pressure) - we typically think of this in regards to the amount of water in the tank, but the control is actually the pressure. Similar the pneumatic tank fills the air blatter - in our case the riser pipe - and fills the downstream pipe with water until pressure fills to a certain point.

          The cycle of the pump running is controlled by the amount of pressure released by release of water - so it is still critical on how much you use. If, for example, you have say 1000 gallons of water in the system pipes and another 200 gallons in the pneumatic tank. If the pneumatic tank pressure various between say 60 psi kicks off the pump and 40 psi kicks on the pump - that relates to how much water is used in the system as well - at say when 600 gallons are removed from the system the amount of pressure in the system (and in turn pneumatic tank) drops down to say 40 psi - when that happens the pump would kick on. - when you pump 600 gallons back into the system the pressure goes back up to 60 psi and kicks the pump off - The amount your pump runs is still dependent on the amount of water you use, but the tank stops it from having to be turned on and off every 20 gallons or so. In the case of Nueva America, given the size of the village, the pump should only be turned on approximately once per week.

          We chose to implement the classic model of the tower, intended to serve from 25 to 100 households. This is 6.5 meters tall. I have included a longer, more detailed description of the technology provided by Plastiforte. It includes some helpful pictures and information.

          I hope this helps and clears up any doubts. Let me know if need any additional information. Much of this information is provided by a water engineer from the States who visited Etta Projects and other nonprofits to study water systems. He agreed that this is a sound system and a great option to reduce the high costs of the expensive water towers.

          Thanks for your query!

          Katie

          • Michael Williamson of Bank-On-Rain

            Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

            Katie,

            OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

            If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

            Thanks,
            Mike

        • Michael Williamson of Bank-On-Rain

          Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

          Katie,

          OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

          If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

          Thanks,
          Mike

      • Katie Chandler of Etta Projects

        Hi Mike, I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for control...

        Hi Mike,

        I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for controlling the pump (similar to a storage tank or elevated tank by holding the pressure). When the pressure drops below a certain pressure the pump kicks on – (in the place of an elevated tank it fills to a certain elevation which is a certain pressure) - we typically think of this in regards to the amount of water in the tank, but the control is actually the pressure. Similar the pneumatic tank fills the air blatter - in our case the riser pipe - and fills the downstream pipe with water until pressure fills to a certain point.

        The cycle of the pump running is controlled by the amount of pressure released by release of water - so it is still critical on how much you use. If, for example, you have say 1000 gallons of water in the system pipes and another 200 gallons in the pneumatic tank. If the pneumatic tank pressure various between say 60 psi kicks off the pump and 40 psi kicks on the pump - that relates to how much water is used in the system as well - at say when 600 gallons are removed from the system the amount of pressure in the system (and in turn pneumatic tank) drops down to say 40 psi - when that happens the pump would kick on. - when you pump 600 gallons back into the system the pressure goes back up to 60 psi and kicks the pump off - The amount your pump runs is still dependent on the amount of water you use, but the tank stops it from having to be turned on and off every 20 gallons or so. In the case of Nueva America, given the size of the village, the pump should only be turned on approximately once per week.

        We chose to implement the classic model of the tower, intended to serve from 25 to 100 households. This is 6.5 meters tall. I have included a longer, more detailed description of the technology provided by Plastiforte. It includes some helpful pictures and information.

        I hope this helps and clears up any doubts. Let me know if need any additional information. Much of this information is provided by a water engineer from the States who visited Etta Projects and other nonprofits to study water systems. He agreed that this is a sound system and a great option to reduce the high costs of the expensive water towers.

        Thanks for your query!

        Katie

        • Michael Williamson of Bank-On-Rain

          Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

          Katie,

          OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

          If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

          Thanks,
          Mike

      • Michael Williamson of Bank-On-Rain

        Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

        Katie,

        OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

        If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

        Thanks,
        Mike

    • Michael Williamson of Bank-On-Rain

      Got it, thanks. Still a bit uncertain about the time between cycles of the pump unless the tower has sufficient volume to act as a temporatry storage tank. Do you know what the tower capacity is? Mike

      Got it, thanks. Still a bit uncertain about the time between cycles of the pump unless the tower has sufficient volume to act as a temporatry storage tank. Do you know what the tower capacity is?

      Mike

      • Katie Chandler of Etta Projects

        Hi Mike, I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for control...

        Hi Mike,

        I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for controlling the pump (similar to a storage tank or elevated tank by holding the pressure). When the pressure drops below a certain pressure the pump kicks on – (in the place of an elevated tank it fills to a certain elevation which is a certain pressure) - we typically think of this in regards to the amount of water in the tank, but the control is actually the pressure. Similar the pneumatic tank fills the air blatter - in our case the riser pipe - and fills the downstream pipe with water until pressure fills to a certain point.

        The cycle of the pump running is controlled by the amount of pressure released by release of water - so it is still critical on how much you use. If, for example, you have say 1000 gallons of water in the system pipes and another 200 gallons in the pneumatic tank. If the pneumatic tank pressure various between say 60 psi kicks off the pump and 40 psi kicks on the pump - that relates to how much water is used in the system as well - at say when 600 gallons are removed from the system the amount of pressure in the system (and in turn pneumatic tank) drops down to say 40 psi - when that happens the pump would kick on. - when you pump 600 gallons back into the system the pressure goes back up to 60 psi and kicks the pump off - The amount your pump runs is still dependent on the amount of water you use, but the tank stops it from having to be turned on and off every 20 gallons or so. In the case of Nueva America, given the size of the village, the pump should only be turned on approximately once per week.

        We chose to implement the classic model of the tower, intended to serve from 25 to 100 households. This is 6.5 meters tall. I have included a longer, more detailed description of the technology provided by Plastiforte. It includes some helpful pictures and information.

        I hope this helps and clears up any doubts. Let me know if need any additional information. Much of this information is provided by a water engineer from the States who visited Etta Projects and other nonprofits to study water systems. He agreed that this is a sound system and a great option to reduce the high costs of the expensive water towers.

        Thanks for your query!

        Katie

        • Michael Williamson of Bank-On-Rain

          Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

          Katie,

          OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

          If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

          Thanks,
          Mike

      • Michael Williamson of Bank-On-Rain

        Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

        Katie,

        OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

        If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

        Thanks,
        Mike

    • Katie Chandler of Etta Projects

      Hi Mike, I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for control...

      Hi Mike,

      I apologize for the confusion. I realize that this technology uses a slightly different concept. In short, the technology works like a typical pneumatic tank that we use here in the states. The "blatter" of air is the pressure that holds the pressure in the system. A pneumatic tank, including this one, is primarily for controlling the pump (similar to a storage tank or elevated tank by holding the pressure). When the pressure drops below a certain pressure the pump kicks on – (in the place of an elevated tank it fills to a certain elevation which is a certain pressure) - we typically think of this in regards to the amount of water in the tank, but the control is actually the pressure. Similar the pneumatic tank fills the air blatter - in our case the riser pipe - and fills the downstream pipe with water until pressure fills to a certain point.

      The cycle of the pump running is controlled by the amount of pressure released by release of water - so it is still critical on how much you use. If, for example, you have say 1000 gallons of water in the system pipes and another 200 gallons in the pneumatic tank. If the pneumatic tank pressure various between say 60 psi kicks off the pump and 40 psi kicks on the pump - that relates to how much water is used in the system as well - at say when 600 gallons are removed from the system the amount of pressure in the system (and in turn pneumatic tank) drops down to say 40 psi - when that happens the pump would kick on. - when you pump 600 gallons back into the system the pressure goes back up to 60 psi and kicks the pump off - The amount your pump runs is still dependent on the amount of water you use, but the tank stops it from having to be turned on and off every 20 gallons or so. In the case of Nueva America, given the size of the village, the pump should only be turned on approximately once per week.

      We chose to implement the classic model of the tower, intended to serve from 25 to 100 households. This is 6.5 meters tall. I have included a longer, more detailed description of the technology provided by Plastiforte. It includes some helpful pictures and information.

      I hope this helps and clears up any doubts. Let me know if need any additional information. Much of this information is provided by a water engineer from the States who visited Etta Projects and other nonprofits to study water systems. He agreed that this is a sound system and a great option to reduce the high costs of the expensive water towers.

      Thanks for your query!

      Katie

      • Michael Williamson of Bank-On-Rain

        Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

        Katie,

        OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

        If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

        Thanks,
        Mike

    • Michael Williamson of Bank-On-Rain

      Katie, OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now re...

      Katie,

      OK, as I understand the system, water from the well is supplied by a submersible pump. What the pneumatic tower does is provide increased system pressure, thereby reducing the number of times the sub-pump must cycle -- is this correct? Now, is the air bladder pressurized by the existing sub-pump in the well, or does this now require an additional pressure pump?

      If there is only 200 gallons in the pneumatic tank, this seems inadequate to supply the number of households served without frequent cycling of the pump. Is the trade-off that the pneumatic tower is less expensive than an elevated storage tank, even when the extra electrical cost of starting/stopping the pump is considered? If this is then the case for the pneumatic tower, could you share with us the calculations used to arrive at this conclusion? I really want to understand the benefit here, and the application does not provide me with enough info.

      Thanks,
      Mike

  • 3 participants | show more

    The technica details

    Gilles Corcos of Agua Para la Vida (APLV)

    The engineers at Plastiforte explained how things worked but did no more than estimate how often the pump will be started.That was the question I and Lynn raised initially. Actually it is difficult to predict because that needs a very complete knowledge of the mode of use of water by the community: As pointed out by Lynn, in period of pe...

    The engineers at Plastiforte explained how things worked but did no more than estimate how often the pump will be started.That was the question I and Lynn raised initially.
    Actually it is difficult to predict because that needs a very complete knowledge of the mode of use of water by the community: As pointed out by Lynn, in period of peak use the demand exceeds the supply and so the pump works continually. Note that during these periods peak use is not attained which is a drawback.
    When the demand falls below the supply the pump provides on a steady basis more water than necessary and stops when the pressure is sufficient to provide the water to the village and starts over again when the pressure has fallen below the lower pressure limit set in the tower. How often that is depends on these consumption rates that are well below the peak rate and which are really not known.

    So to summarize:

    If the pump is designed to withstand frequent starts some of the time the system will work. The question of the consumption of electricity due to frequent starts remains open.
    One more issue which has not been discussed is that during periods of peak use the population will not dispose of the flow rate out of their fawcets that is desired since the pump does not in all likelihood keep up with the demand. In our experience (with gravity systems) when this happens the users tend to improvise individual containers (small tanks and barrels) and to keep all their fawcets open during or before peak use so that the demand is vastly superior to that which is sufficient when the users are confident that the water supply is adequate. I wonder if something similar might happen here.

    • Katie Chandler of Etta Projects

      Hi Gilles and Lynn, Thanks for your comments. Below is information provided by Plastiforte. Let me know if you have any other questions. Thanks again! Katie About the flow calculation: According to Bolivian standards (NORMA BOLIVIANA NB689. INSTALACIONES DE AGUA DISEÑO PARA SISTMAS DE AGUA POTABLE) we use two different f...

      Hi Gilles and Lynn,

      Thanks for your comments. Below is information provided by Plastiforte. Let me know if you have any other questions.

      Thanks again!

      Katie

      About the flow calculation:

      According to Bolivian standards (NORMA BOLIVIANA NB689. INSTALACIONES DE AGUA DISEÑO PARA SISTMAS DE AGUA POTABLE) we use two different formulas for calculating the pump flow:

      1. When the community is less than 30 homes we use a simultaneity factor of 0.2 (instead of the 0.33 stated in the mail) and use design for a flow per tap of 0.1 liters/second (instead of the 1.67 stated in the comment). Nevertheless this type of calculation overestimates demand when you have more than 30 houses. This is usually used only for small rural communities.

      2. When we have more than 30 homes we use a daily allowance ("dotación") which you set at 90 liters/hab/day
      Based on this daily allowance we calculate a daily average flow, a maximum daily flow and a maximum (peak demand) flow as follows:

      Example: NUEVA AMERICA
      Dotación = 90 liters/hab/day
      Population = 40 houses x 5 people = 200 hab
      Average daily flow = 90 x 200 = 18,000 liters/day
      Max daily flow = 18,000 x 1.2 = 21,600 liters/day (this number is needed when you work with storage devices such as tanks. It is calculated multiplying the average daily flow times a factor of 1.2 from the standard)
      Max flow (peak demand) = 21,600/24/3600 x 2 = 0.5 liters/second (this number is need for direct pumping without storage. It is calculated multiplying by a factor of 2 the max daily flow).

      This is the way we calculate flow for up to 10,000 homes.

      About the 20 years project horizon:
      It is a very good idea to design the pipes for a 20 year horizon (80 homes instead of the current 40) but it is a very bad idea to dimension the pump for 20 years because a pump lasts only 5 to 7 years. If you buy a pump twice as big as needed on year one you will spend twice as much money as needed for the first 10 years.
      So for NUEVA AMERICA all we need is a 0.75 - 1.0 HP and in year 10 or so you can replace it for a 2 HP pump when you have more than 70 homes.
      Otherwise you make poor people spend more money for their water.

      About the additional cost of many start-ups a day:
      We do not have scientific research on this nor precise information on the additional power costs generated by many start-ups. We have replaced several existing water tanks that were leaking water for THNs and the water committees have not reported any increase on their power bills now have we seen any from their records.
      We do know this: the amortization cost of a 20,000 USD water tank (needed if you want your pump to start up only once a day) is much higher that the cost of power generated by many start-up. So the THN results in a better option for people who want to pay a very low tariff. This is very obvious to users and economists, but not always to engineers.

      • Lynn Roberts of Agua Para La Salud (APLS)

        The numbers again need to be reviewed for peak demand. The calculation of 21,600/24/3600 x 2 = 0.5 liters/second should be modified from 24 hours to reflect actual use in the village which would be about 65% consumption of water during the morning 5 hour period. The formula would then be 14,040/5/3600 x 2 = 1.56 L/ sec. demand on the syste...

        The numbers again need to be reviewed for peak demand. The calculation of 21,600/24/3600 x 2 = 0.5 liters/second should be modified from 24 hours to reflect actual use in the village which would be about 65% consumption of water during the morning 5 hour period. The formula would then be 14,040/5/3600 x 2 = 1.56 L/ sec. demand on the system. This 5 hour period would utilize the pump similar to the time needed to fill a 14,000 liter tank. Under this situation the tank is optional unless the peak load or use is more than the pump output. If pump output is less than the demand at peak flow then hoarding of water would begin in the village thus over demanding the system further. What safeguards are in place to avoid this hoarding motivation. Will you use water meters and fees?

        • Katie Chandler of Etta Projects

          Hi Lynn, Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste: • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters...

          Hi Lynn,

          Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste:

          • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters in the project design. The cost of each water meter is $58. This is included in the kits for the domestic connection offered by Plastiforte. When necessary, Etta Projects sets up a payment plan to allow for the participation of all families.
          • Etta Projects provides intensive training to local water committees. Included in the training is the calculation of monthly tariffs (which consider the administration, operation & maintenance, expansion, and consumption). Water tariffs are set by the water committee and community members, but generally establish a minimum monthly tariff based on 5 cubic meters per family and a fee for every additional cubic meter. Committee members learn how to maintain monthly books, write receipts, and inform the community of income and expenses related to the water system.
          • Etta Projects works with water committee to create a system of communication between the community and water committee to report any water leaks or other technical problems related to the water system.
          • Etta Projects facilitates workshops with both community members and water committee members that discuss the importance and methods to reduce the usage of water and recycle waste water.

          Thanks again Lynn. Please let me know if you have any other questions or comments.

          Take care,
          Katie

          • Katie Chandler of Etta Projects

            Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

            Hi Lynn,

            Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

            In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

            If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

            The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

            Thanks again!

            Katie

        • Katie Chandler of Etta Projects

          Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

          Hi Lynn,

          Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

          In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

          If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

          The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

          Thanks again!

          Katie

      • Katie Chandler of Etta Projects

        Hi Lynn, Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste: • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters...

        Hi Lynn,

        Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste:

        • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters in the project design. The cost of each water meter is $58. This is included in the kits for the domestic connection offered by Plastiforte. When necessary, Etta Projects sets up a payment plan to allow for the participation of all families.
        • Etta Projects provides intensive training to local water committees. Included in the training is the calculation of monthly tariffs (which consider the administration, operation & maintenance, expansion, and consumption). Water tariffs are set by the water committee and community members, but generally establish a minimum monthly tariff based on 5 cubic meters per family and a fee for every additional cubic meter. Committee members learn how to maintain monthly books, write receipts, and inform the community of income and expenses related to the water system.
        • Etta Projects works with water committee to create a system of communication between the community and water committee to report any water leaks or other technical problems related to the water system.
        • Etta Projects facilitates workshops with both community members and water committee members that discuss the importance and methods to reduce the usage of water and recycle waste water.

        Thanks again Lynn. Please let me know if you have any other questions or comments.

        Take care,
        Katie

        • Katie Chandler of Etta Projects

          Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

          Hi Lynn,

          Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

          In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

          If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

          The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

          Thanks again!

          Katie

      • Katie Chandler of Etta Projects

        Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

        Hi Lynn,

        Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

        In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

        If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

        The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

        Thanks again!

        Katie

    • Lynn Roberts of Agua Para La Salud (APLS)

      The numbers again need to be reviewed for peak demand. The calculation of 21,600/24/3600 x 2 = 0.5 liters/second should be modified from 24 hours to reflect actual use in the village which would be about 65% consumption of water during the morning 5 hour period. The formula would then be 14,040/5/3600 x 2 = 1.56 L/ sec. demand on the syste...

      The numbers again need to be reviewed for peak demand. The calculation of 21,600/24/3600 x 2 = 0.5 liters/second should be modified from 24 hours to reflect actual use in the village which would be about 65% consumption of water during the morning 5 hour period. The formula would then be 14,040/5/3600 x 2 = 1.56 L/ sec. demand on the system. This 5 hour period would utilize the pump similar to the time needed to fill a 14,000 liter tank. Under this situation the tank is optional unless the peak load or use is more than the pump output. If pump output is less than the demand at peak flow then hoarding of water would begin in the village thus over demanding the system further. What safeguards are in place to avoid this hoarding motivation. Will you use water meters and fees?

      • Katie Chandler of Etta Projects

        Hi Lynn, Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste: • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters...

        Hi Lynn,

        Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste:

        • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters in the project design. The cost of each water meter is $58. This is included in the kits for the domestic connection offered by Plastiforte. When necessary, Etta Projects sets up a payment plan to allow for the participation of all families.
        • Etta Projects provides intensive training to local water committees. Included in the training is the calculation of monthly tariffs (which consider the administration, operation & maintenance, expansion, and consumption). Water tariffs are set by the water committee and community members, but generally establish a minimum monthly tariff based on 5 cubic meters per family and a fee for every additional cubic meter. Committee members learn how to maintain monthly books, write receipts, and inform the community of income and expenses related to the water system.
        • Etta Projects works with water committee to create a system of communication between the community and water committee to report any water leaks or other technical problems related to the water system.
        • Etta Projects facilitates workshops with both community members and water committee members that discuss the importance and methods to reduce the usage of water and recycle waste water.

        Thanks again Lynn. Please let me know if you have any other questions or comments.

        Take care,
        Katie

        • Katie Chandler of Etta Projects

          Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

          Hi Lynn,

          Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

          In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

          If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

          The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

          Thanks again!

          Katie

      • Katie Chandler of Etta Projects

        Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

        Hi Lynn,

        Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

        In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

        If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

        The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

        Thanks again!

        Katie

    • Katie Chandler of Etta Projects

      Hi Lynn, Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste: • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters...

      Hi Lynn,

      Thanks again for the feedback. In response to your question regarding water meters and fees, as stated in the project, many precautions are in place to prevent water waste:

      • Included in the family’s contribution of the water system, is the installation of household water meters. Nueva America voted to include water meters in the project design. The cost of each water meter is $58. This is included in the kits for the domestic connection offered by Plastiforte. When necessary, Etta Projects sets up a payment plan to allow for the participation of all families.
      • Etta Projects provides intensive training to local water committees. Included in the training is the calculation of monthly tariffs (which consider the administration, operation & maintenance, expansion, and consumption). Water tariffs are set by the water committee and community members, but generally establish a minimum monthly tariff based on 5 cubic meters per family and a fee for every additional cubic meter. Committee members learn how to maintain monthly books, write receipts, and inform the community of income and expenses related to the water system.
      • Etta Projects works with water committee to create a system of communication between the community and water committee to report any water leaks or other technical problems related to the water system.
      • Etta Projects facilitates workshops with both community members and water committee members that discuss the importance and methods to reduce the usage of water and recycle waste water.

      Thanks again Lynn. Please let me know if you have any other questions or comments.

      Take care,
      Katie

      • Katie Chandler of Etta Projects

        Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

        Hi Lynn,

        Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

        In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

        If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

        The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

        Thanks again!

        Katie

    • Katie Chandler of Etta Projects

      Hi Lynn, Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the syste...

      Hi Lynn,

      Couple things I wanted to add more specifically to your concerns of water hoarding and meeting the demand during peak hours... Water meters are really the biggest factor to make certain families do not overuse water. Obviously, when there are no water meters nor tarifs you need much more water. Also, after revising the system, I noted that the household hook ups AND the water meters are 1/2" not 3/4" - which will restrict the flow to some degree.

      In response to your calculations, we are simply using the BOLIVIAN STANDARD. Please look at pages 19-21 of this text: http://www.emagua.gob.bo/bmmaya/htmls/bib_normas1.html

      If we use coefficients k1 and k2 at the maximum of their range (1.5 instead of 1.2 for k1 and 2.2 instead of 2 for k2) we would get 0.7 l/s at peak hour instead of 0.5.

      The important thing here is that we have enough water at the well, which the experts here show with these calculations. The capacity to fulfill demand at peak time depends only on our pump. We will choose a pump that is big enough for peak demand but small enough so we save energy ( =lower tariff). As population/demand grows we will advise the village to change the pump for a bigger one as necessary (3 - 7 years from now, and be available to monitor their progress.

      Thanks again!

      Katie

  • 2 participants | show more

    Beneficiary counts

    Rajesh Shah of Peer Water Exchange

    Hi Katie, Can you explain what happens (or will happen) to the 20 families who will not get served by the water system? Are you going to have water supply at the school? If no, your counts for school kids should be zero. If yes, it should be 20 since only 20 kids attend school. Why are the other activities hygiene, etc. only targe...

    Hi Katie,

    Can you explain what happens (or will happen) to the 20 families who will not get served by the water system?

    Are you going to have water supply at the school? If no, your counts for school kids should be zero. If yes, it should be 20 since only 20 kids attend school.

    Why are the other activities hygiene, etc. only targeting the 40 families who get water? Why not all 60 families?

    Thanks,
    Rajesh

    • Katie Chandler of Etta Projects

      Hi Rajesh, Thanks for the inquiries. The Municipality's census shows 60 families, but our experience in the village shows only 40. There are a few families that live in dispersed areas (over 1.5 km from the village) that are included in the census. Most have more resources than the families in the concentrated area of the village (th...

      Hi Rajesh,

      Thanks for the inquiries. The Municipality's census shows 60 families, but our experience in the village shows only 40. There are a few families that live in dispersed areas (over 1.5 km from the village) that are included in the census. Most have more resources than the families in the concentrated area of the village (they own small farms or raise cattle) and have implemented their own personal water systems. Village leaders say some families are counted in the census because they own land in dispersed areas, but they do not live in the area. Some lots in the village have abandoned houses, which probably reflect outdated municipal information. The forty families included in the project live permanently in the concentrated area of Nueva America permanently.

      Etta Projects provides training to members of the water committee in how to expand the water system if necessary or add new domestic connections to the water system if families move back/to Nueva America.

      Yes, the school will receive a water connection as well as an additional hygiene education program that targets children. I made that change to the project. Thanks!

      Please let me know if you have any other questions. Thanks again!

      Katie

    • Katie Chandler of Etta Projects

      Hi Rajesh, Thanks for the inquiries. The Municipality's census shows 60 families, but our experience in the village shows only 40. There are a few families that live in dispersed areas (over 1.5 km from the village) that are included in the census. Most have more resources than the families in the concentrated area of the village (th...

      Hi Rajesh,

      Thanks for the inquiries. The Municipality's census shows 60 families, but our experience in the village shows only 40. There are a few families that live in dispersed areas (over 1.5 km from the village) that are included in the census. Most have more resources than the families in the concentrated area of the village (they own small farms or raise cattle) and have implemented their own personal water systems. Village leaders say some families are counted in the census because they own land in dispersed areas, but they do not live in the area. Some lots in the village have abandoned houses, which probably reflect outdated municipal information. The forty families included in the project live permanently in the concentrated area of Nueva America permanently.

      Etta Projects provides training to members of the water committee in how to expand the water system if necessary or add new domestic connections to the water system if families move back/to Nueva America.

      Yes, the school will receive a water connection as well as an additional hygiene education program that targets children. I made that change to the project. Thanks!

      Please let me know if you have any other questions. Thanks again!

      Katie

      • Rajesh Shah of Peer Water Exchange

        Thanks for the reply, glad to see you are going for 100% coverage. Downloaded all your files (lots of Mb!). In future, please use the upload photos, because we have a wonderful way of displaying photos (at different resolutions) without putting real strain on the internet connection. And they become searchable too. Actually, will ...

        Thanks for the reply, glad to see you are going for 100% coverage.

        Downloaded all your files (lots of Mb!).

        In future, please use the upload photos, because we have a wonderful way of displaying photos (at different resolutions) without putting real strain on the internet connection. And they become searchable too.

        Actually, will work with you to put the before/after photos up on your previous project (that's where they belong).

        In future i would like to see more connections with others designing and improvising as you have done. I helped design a lower-cost triangular design for a squatting toilet that shared the urine diversion. Reduced size, cost of walls and construction.

        Regards,
        Rajesh

        • Katie Chandler of Etta Projects

          Thanks Rajesh, I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine c...

          Thanks Rajesh,

          I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine can leave the system?

          Thanks again for everything.

          Katie

      • Katie Chandler of Etta Projects

        Thanks Rajesh, I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine c...

        Thanks Rajesh,

        I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine can leave the system?

        Thanks again for everything.

        Katie

    • Rajesh Shah of Peer Water Exchange

      Thanks for the reply, glad to see you are going for 100% coverage. Downloaded all your files (lots of Mb!). In future, please use the upload photos, because we have a wonderful way of displaying photos (at different resolutions) without putting real strain on the internet connection. And they become searchable too. Actually, will ...

      Thanks for the reply, glad to see you are going for 100% coverage.

      Downloaded all your files (lots of Mb!).

      In future, please use the upload photos, because we have a wonderful way of displaying photos (at different resolutions) without putting real strain on the internet connection. And they become searchable too.

      Actually, will work with you to put the before/after photos up on your previous project (that's where they belong).

      In future i would like to see more connections with others designing and improvising as you have done. I helped design a lower-cost triangular design for a squatting toilet that shared the urine diversion. Reduced size, cost of walls and construction.

      Regards,
      Rajesh

      • Katie Chandler of Etta Projects

        Thanks Rajesh, I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine c...

        Thanks Rajesh,

        I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine can leave the system?

        Thanks again for everything.

        Katie

    • Katie Chandler of Etta Projects

      Thanks Rajesh, I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine c...

      Thanks Rajesh,

      I would love to know more about the triangular sanitation design. I have spent a good deal of my time this month visiting different models...they all seem to have their pros and cons. I know you are busy, but when you have some time, I'd love to learn more about that. What kind of tubing model do you use so the urine can leave the system?

      Thanks again for everything.

      Katie

  • 4 participants | show more

    Tank Air Cushion and Water Volumn

    Lynn Roberts of Agua Para La Salud (APLS)

    The technology in the tower application is one that I encountered about 45 years ago in water pumping systems about the time the plastic bladder was introduced to solve the cronic problem in pumping systems in which hydro-neumatic tanks without bladders developed. The problem was that the water in the tank would absorb the air cushion and ...

    The technology in the tower application is one that I encountered about 45 years ago in water pumping systems about the time the plastic bladder was introduced to solve the cronic problem in pumping systems in which hydro-neumatic tanks without bladders developed. The problem was that the water in the tank would absorb the air cushion and cause rapid or at least frequent cycling of the pump as the air volumn decreased. This situation required that the air in the tank be replaced periodically.

    Have provisions been made to train villagers and supply them with equipment to make this replacement of air in the tower?
    Has the manufacturer of the tower addressed this situation? Have they installed an access ( small valve) in the tower wall so that the water/air levels can be tested to see if the air space is remaining constant.

    If 40 families are using 50 liters per day this would amount to an average of 2000liters per day demand from the tower and the pump. With about 4 liters per gallon this would amount to about 500 gallons per day. If the tower has a pump down ( 200 gallon storage volumn between pump cycles) then the pump would run 2.5 times a day to replenish the tower. Provided the well can sustain this rate of pumping then the system should be able to sustain the water need. Have well pumping tests been done to understand the wells capability? In other words has the well been pumped 2.5 times at the volumn of 1000 liters or 250 gallons over a 12 hour period over several days and the well water level measured to check recovery time of the well water level ?

    • Gilles Corcos of Agua Para la Vida (APLV)

      Lynn: You've assumed 50 liters per day per family. That's a pretty skinny allowance (At most 10 liters per inhabitant). I assumed about five times that. Also if the cycling frequency is raised to more than twice a day for that reason, the question you raised earlier ( the need for a distribution tank to avoid peak use to make excessive d...

      Lynn:
      You've assumed 50 liters per day per family. That's a pretty skinny allowance (At most 10 liters per inhabitant). I assumed about five times that. Also if the cycling frequency is raised to more than twice a day for that reason, the question you raised earlier ( the need for a distribution tank to avoid peak use to make excessive demands on the bladder-tank) becomes more important. And it is clear that a distribution tank is cheaper to build than a pressurized bladder -tank.

      Gilles

      • Lynn Roberts of Agua Para La Salud (APLS)

        I agree Gilles. I was using the small number to attempting to point out that the pump would cycle much more frequently. Also tha assumption that the piping some how increases the amount of water available for the pump down is a false assumption. ( This would be true in a gravity fed water system without a tank. We have used this concept wh...

        I agree Gilles. I was using the small number to attempting to point out that the pump would cycle much more frequently. Also tha assumption that the piping some how increases the amount of water available for the pump down is a false assumption. ( This would be true in a gravity fed water system without a tank. We have used this concept when we have a large spring flow)
        Only the water in the tower will be available during the pump down or cycling of the pump. As you say this points out the need for a tank of larger capacity or a considerable number of pump cycles per day to supply about 200 people with 50 liters per day (10,000 liters). It would be advised that an electric counter be attached to the pump over a period of time to count these cycles before a great deal of these systems are installed so that the operation is better understood and the claims of the manufacturing company proven.
        It would also be simple to have a person stand by the pump for a morning and count the cycles during the peak use ( 6am--11am). I have a small system such as this in my home and the pump cycles at least twice during a long shower with a 4 gallon pump down of the tank and bladder.In the system under discussion if each home draws 5 liters the tower will empty and the pump will cycle.
        I am making the assumption that the tower is about level with the 40 homes. If the homes are higher than the tower then the available water between pump downs will be less.

        • Michael Williamson of Bank-On-Rain

          Lynn, Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well? If this is the case, it might be helpful to modify the application with the primary objective clearly stated. Thanks, Mike

          Lynn,

          Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well?

          If this is the case, it might be helpful to modify the application with the primary objective clearly stated.

          Thanks,
          Mike

          • Katie Chandler of Etta Projects

            Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

            Hi Mike,

            In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

            Thanks,
            Katie

            • Michael Williamson of Bank-On-Rain

              OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

              OK, Lynn, I think I've got it now.

              The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

              Thanks,
              Mike

          • Michael Williamson of Bank-On-Rain

            OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

            OK, Lynn, I think I've got it now.

            The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

            Thanks,
            Mike

        • Katie Chandler of Etta Projects

          Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

          Hi Mike,

          In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

          Thanks,
          Katie

          • Michael Williamson of Bank-On-Rain

            OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

            OK, Lynn, I think I've got it now.

            The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

            Thanks,
            Mike

        • Michael Williamson of Bank-On-Rain

          OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

          OK, Lynn, I think I've got it now.

          The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

          Thanks,
          Mike

      • Michael Williamson of Bank-On-Rain

        Lynn, Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well? If this is the case, it might be helpful to modify the application with the primary objective clearly stated. Thanks, Mike

        Lynn,

        Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well?

        If this is the case, it might be helpful to modify the application with the primary objective clearly stated.

        Thanks,
        Mike

        • Katie Chandler of Etta Projects

          Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

          Hi Mike,

          In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

          Thanks,
          Katie

          • Michael Williamson of Bank-On-Rain

            OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

            OK, Lynn, I think I've got it now.

            The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

            Thanks,
            Mike

        • Michael Williamson of Bank-On-Rain

          OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

          OK, Lynn, I think I've got it now.

          The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

          Thanks,
          Mike

      • Katie Chandler of Etta Projects

        Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

        Hi Mike,

        In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

        Thanks,
        Katie

        • Michael Williamson of Bank-On-Rain

          OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

          OK, Lynn, I think I've got it now.

          The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

          Thanks,
          Mike

      • Michael Williamson of Bank-On-Rain

        OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

        OK, Lynn, I think I've got it now.

        The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

        Thanks,
        Mike

    • Lynn Roberts of Agua Para La Salud (APLS)

      I agree Gilles. I was using the small number to attempting to point out that the pump would cycle much more frequently. Also tha assumption that the piping some how increases the amount of water available for the pump down is a false assumption. ( This would be true in a gravity fed water system without a tank. We have used this concept wh...

      I agree Gilles. I was using the small number to attempting to point out that the pump would cycle much more frequently. Also tha assumption that the piping some how increases the amount of water available for the pump down is a false assumption. ( This would be true in a gravity fed water system without a tank. We have used this concept when we have a large spring flow)
      Only the water in the tower will be available during the pump down or cycling of the pump. As you say this points out the need for a tank of larger capacity or a considerable number of pump cycles per day to supply about 200 people with 50 liters per day (10,000 liters). It would be advised that an electric counter be attached to the pump over a period of time to count these cycles before a great deal of these systems are installed so that the operation is better understood and the claims of the manufacturing company proven.
      It would also be simple to have a person stand by the pump for a morning and count the cycles during the peak use ( 6am--11am). I have a small system such as this in my home and the pump cycles at least twice during a long shower with a 4 gallon pump down of the tank and bladder.In the system under discussion if each home draws 5 liters the tower will empty and the pump will cycle.
      I am making the assumption that the tower is about level with the 40 homes. If the homes are higher than the tower then the available water between pump downs will be less.

      • Michael Williamson of Bank-On-Rain

        Lynn, Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well? If this is the case, it might be helpful to modify the application with the primary objective clearly stated. Thanks, Mike

        Lynn,

        Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well?

        If this is the case, it might be helpful to modify the application with the primary objective clearly stated.

        Thanks,
        Mike

        • Katie Chandler of Etta Projects

          Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

          Hi Mike,

          In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

          Thanks,
          Katie

          • Michael Williamson of Bank-On-Rain

            OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

            OK, Lynn, I think I've got it now.

            The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

            Thanks,
            Mike

        • Michael Williamson of Bank-On-Rain

          OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

          OK, Lynn, I think I've got it now.

          The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

          Thanks,
          Mike

      • Katie Chandler of Etta Projects

        Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

        Hi Mike,

        In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

        Thanks,
        Katie

        • Michael Williamson of Bank-On-Rain

          OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

          OK, Lynn, I think I've got it now.

          The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

          Thanks,
          Mike

      • Michael Williamson of Bank-On-Rain

        OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

        OK, Lynn, I think I've got it now.

        The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

        Thanks,
        Mike

    • Michael Williamson of Bank-On-Rain

      Lynn, Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well? If this is the case, it might be helpful to modify the application with the primary objective clearly stated. Thanks, Mike

      Lynn,

      Just for clarification, is the pupose of adding the tower to provide sufficent mains pressure to serve more homes from an existing well?

      If this is the case, it might be helpful to modify the application with the primary objective clearly stated.

      Thanks,
      Mike

      • Katie Chandler of Etta Projects

        Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

        Hi Mike,

        In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

        Thanks,
        Katie

        • Michael Williamson of Bank-On-Rain

          OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

          OK, Lynn, I think I've got it now.

          The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

          Thanks,
          Mike

      • Michael Williamson of Bank-On-Rain

        OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

        OK, Lynn, I think I've got it now.

        The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

        Thanks,
        Mike

    • Katie Chandler of Etta Projects

      Hi Mike, In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many othe...

      Hi Mike,

      In case I didn't answer your questions in my previous email, the purpose of the tower is to make use of an existing water well that is currently not in use. Families in Nueva America use contaminated shallow water wells or a stream to retrieve water. The state government perforated the well a few years ago, but like many other villages in the Department of Santa Cruz, the wells remain unused.

      Thanks,
      Katie

      • Michael Williamson of Bank-On-Rain

        OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

        OK, Lynn, I think I've got it now.

        The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

        Thanks,
        Mike

    • Michael Williamson of Bank-On-Rain

      OK, Lynn, I think I've got it now. The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life. Thanks, Mike

      OK, Lynn, I think I've got it now.

      The deep well requires a sub-pump anyway, so sounds like the addition of the pneumatic tower improves the system's ability to service the entire community and should increase the pump life.

      Thanks,
      Mike

  • 4 participants | show more

    Response to your questions...

    Katie Chandler of Etta Projects

    Hi All, I apologize that I did not get back to you earlier. I have been out of the office for the last couple days. What exciting conversation! I’m so enjoying this dialogue because it’s been such a great opportunity to learn more about this water system. Thank you. So, in response to your inquiries…. Etta Projects’ exper...

    Hi All,

    I apologize that I did not get back to you earlier. I have been out of the office for the last couple days. What exciting conversation! I’m so enjoying this dialogue because it’s been such a great opportunity to learn more about this water system. Thank you.

    So, in response to your inquiries….

    Etta Projects’ experience with the system:

    As you may have guessed this is a new technology used by Etta Projects. Etta Projects is currently implementing the same technology in a different village, Montegrande, but due to the heavy rains we faced this year we have had to postpone the implementation of the water system on a number of occasions. It’s scheduled to go in next week! Etta Projects has had the opportunity for our in-country staff to travel to Cochabamba on a number of occasions to receive training directly from Plastiforte and to meet with other nonprofits that are using this same system, including the reputable Water For People. Joe Sesil, a water engineer and member of PWX who commented above (thanks, Joe, for your expertise :-)), also met with Plastiforte and gave the system his stamp of approval. Because we learned from experts in the field such as Joe and we saw firsthand successful cases of other nonprofits using this water system with great success and community satisfaction, we opted to move forward with this technology. Again it seems like a cost effective alternative to the elevated water tank that works well in villages similar to Nueva America, and it protects the quality of the water before distribution.

    In response to your inquiries....

    Electricity:

    As Joe mentioned, Nueva America has a reliable source of electricity with few power outages. Many villages in the surrounding area have water systems that run on electrical pumps, and we have not observed any major issues or prolonged periods of water shortages.

    The life of the water pump has a life span of 7 to 10 years (I believe I was being conservative by giving 5 years). Unfortunately even though the area has high electricity coverage, the life span of the pump could be impacted by the high and low voltage in the communities. We have not seen this occur in any village where we implemented water systems, but recognize this as a potential risk. During our training program we make water committees aware of this risk. Local municipalities should help villages replace pumps in these cases if the village solicits their support. The cost can fluctuate for a pump repair, but even in the more serious cases, to change a pump would cost between $1000 to $2000.

    The cost of electricity in the rural areas to run the pump is low. It is likely that communities of up to about 50 families, spend a maximum of 200 Bs/month. (less than 30$ us/month).

    Ongoing Support:

    The project includes intensive training of a 6-member water committee that will manage the water system. The members will participate in workshops related to Committee Organizational Structure; Roles & Responsibilities; Financial Management; Mobilizing the Village; Water Quality; Hygiene; and Technical Operation and Management of the Water System. The training sessions will spread over 9 months and will include a 5-day intensive training course in Cochabamba by Plastiforte. After completion of the project cycle, Etta Projects will make bimonthly visits to Nueva America to monitor the administration and sustainability of the water system. We will also participate in some of the regular monthly community meetings, where the water committee’s monthly report will be incorporated into the regular agenda (the committee will report to the community the financials and other relevant matters). Etta Projects is also coordinating and partnering with the local municipality who is also responsible for continued monitoring the water system.

    Water System:

    The pipe is 1000 meters long and has a diameter of 3 inches. The data that Plastiforte gave regarding the pump turning on once per week is just one case example we were given. I apologize if I was not clear in my explanation. I will try to clarify…

    The tower works with the pumps to maintain a stable water system pressure. The system pressure is controlled by a pressure switch set for minimum and maximum pressures – giving us a cut-in and a cut-out pressure for the pumps. As water is drawn down, the system pressure starts to drop. When it reaches the minimum system pressure, the pump cuts back in and runs until the system pressure reaches the normal maximum pressure.

    The system is precharged with air to a pressure that is close to the minimum system pressure (the cut-in pressure). As the system fills, water is pumped into the bladder, compressing the air cushion in the tank. This causes an increase in system pressure. The pumps continue to run until the system pressure reaches the maximum setting (the cut-out pressure for the pump). As water is drawn from the system, the pressure will begin to decrease. When the system pressure reaches the minimum setting, the pumps will turn back on and restart the cycle. Maintaining a stable air pressure ensures that the system will run at peak efficiency, preventing the pumps from short-cycling.

    According to Plastiforte, this system has the capacity to serve up to 100 homes. We are serving 40 families. The classic tower can control pressure control with a range of adjustment from 1.0 to 4.6 bars. At peak hours of water consumption, the pump may function two possibly three times a day. There may also be days that is should not have to turn on. Included in this project is the installation of domestic water meters, therefore families will be more compelled to conserve water and not leave faucets running.

    The pressure switch is the main component that will need to be replaced. The cost is $30-$50. Most electrical technicians can do this work, and it does not have to be done by Plastiforte. All other tower parts are covered by the guarantee from Plastiforte for up to 20 years.

    According to Engineer John Rodriguez from Water For People the “tower requires virtually no maintenance and system operates without major problems.” Water For People is currently installing 3 more towers in the peri urban of Cochabamba. John states, “If you ask me, in general, I think that that this technology works very well, in normal conditions of water quality and with a good network of energy. It can easily last 7-10 years without problems.” John says that WFP implemented these systems, they have measured both the sustainability of the water system and community satisfaction. He says this system offers both.

    In response to your questions regarding the well: The depth of the well is 122 meters (w/ 4” diameter). The water table is high in this area; the static water level being 13 meters. According to statistics provided by the Prefecture the well has the capability to pump 7920 liters per hour.

    Again, I appreciate all your comments. I realize that I don’t have all the specifics, but I am heading to Bolivia on August 8, hopefully in time to participate in the inauguration of a water system using this same technology in the village Montegrande. I look forward to speaking directing with the representatives at Plastiforte and getting more detailed information. In the meantime, I hope this clarified some of your questions and concerns. To be honest, many of your comments caused me to stop and reflect about the quality and sustainability of this technology. The bottom line is that Etta Projects wants to do both what is in our capacity and what’s best for this village. Etta Projects is committed to providing a sustainable water system to the village Nueva America, we are not committed to a specific technology…; however, based on information and observation of this water system, characteristics of the community and by positive reviews of it by water experts, we trust this system to be a viable option.

    Thanks again and I look forward to ongoing discussions!

    Katie

    • Gilles Corcos of Agua Para la Vida (APLV)

      dear Katie: You did not answer my question. I was not questioning the bladder system for keeping the pressure sufficiently high to get decent delivery at the end of the distribution network. I was asking about the tank, (I think somehow that word did not print in my earlier message). Whatever water is provided to the village in a given ...

      dear Katie:

      You did not answer my question. I was not questioning the bladder system for keeping the pressure sufficiently high to get decent delivery at the end of the distribution network. I was asking about the tank, (I think somehow that word did not print in my earlier message). Whatever water is provided to the village in a given amount of time before the pump is started again has necessarily got to come from the tank.If you decide on a maximum cycling frequency (frequency for the pump to start), that settles the community water allowance for that time (given the amount provided per day for the population). The cycling frequency you mentioned in response to another person involved a very large tank indeed as I showed you. Your group or your engineering firm must have decided on a tank volume and a tank water-providing capacity between pumping events and I would like to know what these numbers are and what is the cost of such a tank which must withstand 4 atmospheres.

      Thank you,
      Gilles

      • Joe Sesil of Team Blue

        Hi Gilles, My understanding is that the system does not have a storage tank and uses the pneumatic tower to control the pump cycle. The available volume of water is the amount of water in the pipe and in the tower itself. The pipe as Katie referenced is a 3" or 8 cm pipe and the system has approximately 1000 meters of pipe. I believe t...

        Hi Gilles,

        My understanding is that the system does not have a storage tank and uses the pneumatic tower to control the pump cycle. The available volume of water is the amount of water in the pipe and in the tower itself. The pipe as Katie referenced is a 3" or 8 cm pipe and the system has approximately 1000 meters of pipe. I believe the tower adds minimal additional capacity, so the pipe volume is the available capacity between pump off/on cycles.

        I hope I am helping to answer the question and not adding more confusion, but wanted to try to help if I could.

        Thanks and all the best,

        Joe

        • Gilles Corcos of Agua Para la Vida (APLV)

          Thank you Joe : You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning: The total daily water allotment The peak hours water allotment and for what interval of time. The level difference between the beginning and the end of the main. The ratio of the assumed useful to...

          Thank you Joe :

          You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning:

          The total daily water allotment
          The peak hours water allotment and for what interval of time.
          The level difference between the beginning and the end of the main.
          The ratio of the assumed useful to the actual volume of the that is of the piping system.
          The flow rate of the pump.
          Also is the total volume of the connecting pipes between main and water distribution points negligible next to that of the main?
          I assume that ETTA and/or its supplier can provide this data.

          But it would be desirable for organizations that offer novel or unusual technologu to provide initially sufficient technical data or to be prepared to answer technical questions.

          • Katie Chandler of Etta Projects

            Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

            Hi All,

            Thanks again for all the comments.

            This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

            A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

            Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

            An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

            Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

            I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

            Please let me know if you have any other questions.

            Thanks much!

            Katie

        • Katie Chandler of Etta Projects

          Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

          Hi All,

          Thanks again for all the comments.

          This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

          A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

          Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

          An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

          Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

          I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

          Please let me know if you have any other questions.

          Thanks much!

          Katie

      • Gilles Corcos of Agua Para la Vida (APLV)

        Thank you Joe : You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning: The total daily water allotment The peak hours water allotment and for what interval of time. The level difference between the beginning and the end of the main. The ratio of the assumed useful to...

        Thank you Joe :

        You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning:

        The total daily water allotment
        The peak hours water allotment and for what interval of time.
        The level difference between the beginning and the end of the main.
        The ratio of the assumed useful to the actual volume of the that is of the piping system.
        The flow rate of the pump.
        Also is the total volume of the connecting pipes between main and water distribution points negligible next to that of the main?
        I assume that ETTA and/or its supplier can provide this data.

        But it would be desirable for organizations that offer novel or unusual technologu to provide initially sufficient technical data or to be prepared to answer technical questions.

        • Katie Chandler of Etta Projects

          Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

          Hi All,

          Thanks again for all the comments.

          This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

          A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

          Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

          An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

          Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

          I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

          Please let me know if you have any other questions.

          Thanks much!

          Katie

      • Katie Chandler of Etta Projects

        Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

        Hi All,

        Thanks again for all the comments.

        This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

        A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

        Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

        An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

        Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

        I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

        Please let me know if you have any other questions.

        Thanks much!

        Katie

    • Joe Sesil of Team Blue

      Hi Gilles, My understanding is that the system does not have a storage tank and uses the pneumatic tower to control the pump cycle. The available volume of water is the amount of water in the pipe and in the tower itself. The pipe as Katie referenced is a 3" or 8 cm pipe and the system has approximately 1000 meters of pipe. I believe t...

      Hi Gilles,

      My understanding is that the system does not have a storage tank and uses the pneumatic tower to control the pump cycle. The available volume of water is the amount of water in the pipe and in the tower itself. The pipe as Katie referenced is a 3" or 8 cm pipe and the system has approximately 1000 meters of pipe. I believe the tower adds minimal additional capacity, so the pipe volume is the available capacity between pump off/on cycles.

      I hope I am helping to answer the question and not adding more confusion, but wanted to try to help if I could.

      Thanks and all the best,

      Joe

      • Gilles Corcos of Agua Para la Vida (APLV)

        Thank you Joe : You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning: The total daily water allotment The peak hours water allotment and for what interval of time. The level difference between the beginning and the end of the main. The ratio of the assumed useful to...

        Thank you Joe :

        You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning:

        The total daily water allotment
        The peak hours water allotment and for what interval of time.
        The level difference between the beginning and the end of the main.
        The ratio of the assumed useful to the actual volume of the that is of the piping system.
        The flow rate of the pump.
        Also is the total volume of the connecting pipes between main and water distribution points negligible next to that of the main?
        I assume that ETTA and/or its supplier can provide this data.

        But it would be desirable for organizations that offer novel or unusual technologu to provide initially sufficient technical data or to be prepared to answer technical questions.

        • Katie Chandler of Etta Projects

          Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

          Hi All,

          Thanks again for all the comments.

          This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

          A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

          Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

          An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

          Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

          I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

          Please let me know if you have any other questions.

          Thanks much!

          Katie

      • Katie Chandler of Etta Projects

        Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

        Hi All,

        Thanks again for all the comments.

        This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

        A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

        Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

        An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

        Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

        I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

        Please let me know if you have any other questions.

        Thanks much!

        Katie

    • Gilles Corcos of Agua Para la Vida (APLV)

      Thank you Joe : You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning: The total daily water allotment The peak hours water allotment and for what interval of time. The level difference between the beginning and the end of the main. The ratio of the assumed useful to...

      Thank you Joe :

      You're probably right. Now to assess the possibilities of that system we need more data from the designers . Meaning:

      The total daily water allotment
      The peak hours water allotment and for what interval of time.
      The level difference between the beginning and the end of the main.
      The ratio of the assumed useful to the actual volume of the that is of the piping system.
      The flow rate of the pump.
      Also is the total volume of the connecting pipes between main and water distribution points negligible next to that of the main?
      I assume that ETTA and/or its supplier can provide this data.

      But it would be desirable for organizations that offer novel or unusual technologu to provide initially sufficient technical data or to be prepared to answer technical questions.

      • Katie Chandler of Etta Projects

        Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

        Hi All,

        Thanks again for all the comments.

        This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

        A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

        Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

        An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

        Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

        I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

        Please let me know if you have any other questions.

        Thanks much!

        Katie

    • Katie Chandler of Etta Projects

      Hi All, Thanks again for all the comments. This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has acc...

      Hi All,

      Thanks again for all the comments.

      This system has 1000 meters of pipes and has a diameter of 8 cm, therefore holding approximately 1,250 liters of water (please note, the available volume will be slightly less than the total volume because the system kicks on at 1 bar and not when totally empty). Once the village has access to running water we can estimate daily use per person is approximately 100 liters of water per day (according to stats, in Bolivia in villages of under 500 people daily consumption is 70-90 liters per person in areas similar to Nueva America (I posted this chart on the documents portion of the application). We found that the consumption varies with size of household and with the ages of people living in the home. However, with 200 people in the village, we can generous daily prediction of an average daily consumption of 20,000 liters. Given this information, the system will need to reload up to 16 times per day. This would be under circumstances of high consumption.

      A normal 1.5 HP pump is capable of producing 20-100 liters per minute, with an average of 1 L per second. Given this information, the pump would need to run for just under 20 minutes per refill.

      Peak hours are early morning (6-730), mid-morning (10-11) while women wash clothing and again during the evening for cooking. My experience is that when a faucet is turned on in a village it takes just under one minute or 60 seconds to fill 6 liters of water. Considering the available volume, it would take one household around 200 minutes of running their water before the pump would need to turn on again. Now if all 40 households had their faucet running at the same time, in about one minute they would consume 240 liters of water. In this case, in about five minutes the demand would consume the volume of the system. The pump would actually be kicking on and off less than this because this system is dynamic making the frequency of the pump even less than the calculations above, which consider if to be static. For example, during peak hours when the demand brings the pressure down to 1 bar the pump will actually be filling the current demand and trying to refill the system simultaneously, causing the on-and-off of the pump to decrease.

      An important thing to consider is that pump includes a European pump that has the capacity to turn on and off frequently, as many times as 60 times per hour. This is not predicted (data provided by the manufacturer of the hydropneumatic tower shows the pump use as very low). EP will be running tests in Montegrande (where we are currently implementing the system) and I will report our findings.

      Again, the well has the capacity to pump 7920 liters per hour, so there is enough available water to serve even peak demands of the system.

      I hope this clears up some of your concerns. As I said, this is a new technology for Etta Projects and I apologize for any confusion. I realize much of the information we received from the manufacturer seems a little overly conservative, particularly on the use of the water pump.

      Please let me know if you have any other questions.

      Thanks much!

      Katie

    • Michael Williamson of Bank-On-Rain

      Katie, Thanks for the explanation. The pressure tanks with air bladders work reliably for many years on well systems I am familiar with, so I don't see why a larger system serving a community would not perform similarly. It sound as if the local electrical power is heavily subsidized, otherwise the cost of power may play a role in...

      Katie,

      Thanks for the explanation. The pressure tanks with air bladders work reliably for many years on well systems I am familiar with, so I don't see why a larger system serving a community would not perform similarly.

      It sound as if the local electrical power is heavily subsidized, otherwise the cost of power may play a role in the cost-benefit evaluation. As a test of a technology for small community systems, it sounds like a worthwhile experiment.

      Thank you for filling in some of the blanks,
      Mike

  • 3 participants | show more

    Again the technology

    Gilles Corcos of Agua Para la Vida (APLV)

    Hello Katie: If you have followed the dialogue between Lynn and me you have to guess that we will both be loath to approve your project, since we both feel that the system proposed will function quite differently from the way you described it. In particular (this is me, talking) the cycling frequency of the pump will be entirely gov...

    Hello Katie:

    If you have followed the dialogue between Lynn and me you have to guess that we will both be loath to approve your project, since we both feel that the system proposed will function quite differently from the way you described it.

    In particular (this is me, talking) the cycling frequency of the pump will be entirely governed by the capacity of the vertical column itself, the flow rate of the pump, the modulus of elasticity and thickness of your 8cm pipe and naturally the mode of use of the water by the villagers. It risks under the present design to be very high indeed.

    It is the fundamental engineering of the system that we are challenging. I think your system will function like one with a bladder-tank whose bladder has busted. Under these conditions It would be preferable, I think for your engineering team to review and modify its design and to resubmit the project afterwards.

    Believe me, I am not at all inclined to oppose the water projects of others. I'd even be willing to help modify the design.

    Cordially,

    Gilles

    • Katie Chandler of Etta Projects

      Hi Gilles and Lynn I just arrived to Bolivia yesterday, and look forward to connecting with members of Plastiforte in the near future. I am not an Engineer and I hope I haven't failed this project due to my own lack of Engineering knowledge and therefore by obviously insufficient responses. I will respond to your concerns after communi...

      Hi Gilles and Lynn

      I just arrived to Bolivia yesterday, and look forward to connecting with members of Plastiforte in the near future. I am not an Engineer and I hope I haven't failed this project due to my own lack of Engineering knowledge and therefore by obviously insufficient responses. I will respond to your concerns after communicating directly with them.

      I do want you to recognize that there are more than 40 systems in the Cochabamba area, both in rural and unban neighborhoods, functioning without problems. Some of these have more than eight years of use. Our staff in Bolivia accompanied Plastiforte and Water for People to some of these villages to observe the system and speak directly with the members of these communities. Their findings were positive. Furthermore this system is approved by the Ministry of Environmental & Natural Resources and Water in Bolivia and is included in their recommended list of water systems.

      Thanks,
      Katie

      • Katie Chandler of Etta Projects

        Hello! I traveled to Cochabamba last night and finally had the opportunity to meet directly with the Engineers from Plastiforte and inquire about some of your concerns related to the hydropneumatic tower. After meeting with them, I need to make some clarifications as there were obviously some miscommunications between Etta Projects’ s...

        Hello!

        I traveled to Cochabamba last night and finally had the opportunity to meet directly with the Engineers from Plastiforte and inquire about some of your concerns related to the hydropneumatic tower. After meeting with them, I need to make some clarifications as there were obviously some miscommunications between Etta Projects’ staff in Bolivia and the crew at Plastiforte. After today´s visit, I am convinced that the system is a viable system that is not only currently effectively working in many communities in Bolivia, but will also work effectively in the village Nueva America where we are proposing this project.

        In Bolivia there are three commonly used water systems: an elevated water tank, a pressure tank, and (most recently used)the hydropneumatic water tower. The main difference between the pressure tank and the hydropneumatic water tower (being proposed in the project) is that a pressure tank has a bladder that controls the amount of pressure in the system (the bladder expands and deflates with the amount of water and pressure in the system). A hydropneumatic water tower, however, uses a cylinder of air that controls the pressure inside the tower. This system was invented here in Bolivia (by a Bolivian Engineer that was trained at Georgia Tech) and has been used in Bolivia for the past 15 years. The concept is the same as the pressure tank, but instead of using a bladder it uses a cylinder (or various cylinders) that holds air pressure. The air pressure is set according to the characteristics of the village (elevation, water demand, typography, etc); for a village such as Nueva America the pressure is usually controlled between 1.4 and 2.8 bars. The system includes a manometer which shows the pressure in the system at any given time and a pressure switch that regulates the amount of pressure in the system.

        Both the hydropneumatic tower and the pressure tower preserve the quality of water and act as a single line of water distribution (large quantities of water are not being stored for later use as in an elevated tank). The advantage of the hydropneumatic tower is that there is no bladder that can rupture and that needs to be consistently changed and maintained. The hydropneumatic tower is a simpler system that carries a longer lifeline. The only part that needs to be replaced is the pressure switch. Again, this costs $30 to $50.

        The distribution system in Nueva America will uses HDPE tubing which is known for its elasticity and resistance to extreme temperatures. Our water system will be controlled between 1.4 and 2.8 bars. The optimal use of the tubing is up to 6 bars, therefore eliminating risks of bursting pipes. In reality, the tubes have a resistance of up to 15 bars.

        There are three brands of water pumps that are recommended for this system: perrollo, caprari and grudfos. All three models allow a water flow of up to 100 liters per minute. They are known for their capacity to switch on and off as many as 60 times per hour. I learned today that the system does in fact require much more frequent use of the water pump than previously reported, and I expressed our concerns about the extra energy needed to turn the pump on and off throughout the day (versus that prolonged use of filling an elevated tank). They said that the system is different than a car or large motor that takes time to reach normal use; the water pump will reach normal speed in less than a millisecond and therefore does not expend a lot of energy each time it is activated.

        After speaking with members of Plastiforte, I met with the folks from Water for People to ask why they have turned to this system over the elevated water tank. They explained various problems they had faced over the years with the elevated water tanks, including: the ability of the operator to correctly fulfill his/her daily responsibilities of filling the tank, the need to pay the operator more money for sustainability, how various untrained people turn the pump on and off when the operator is not present, the negative consequences that occur when the operator gets bored waiting for the tank to fill and forgets to shut off the pump, how there is no water in the community if the tank empties and the community waits for operator to be available to fill it, the contamination of water in the water tank (the project director said you can visibly see the difference in the quality of water between water leaving the hydropneumatic tower and a water tank), and maintenance costs to clean the tank. Rosario Villarpando Project Director from Water For People said, ¨If it´s a question of the quality of water, the cost of the system and the maintenance of the system I only see advantages to the hydropneumatic tower compared to the elevated water tank.¨ She noted that certain conditions have to be present in a village (constant electricity, a viable well) but based on her experience, she highly preferred the hydropneumatic tower to the elevated water tower. She again confirmed that the price of the electricity bills do not alter between the tank and the tower, both being around 200-250 Bs ($28-$36) monthly for as village the size of Nueva America.

        I am including some pictures of the various parts of the system in the attachment section that may be helpful. Tomorrow I am meeting again with the Engineers from Plastiforte to do a long-term cost analysis of the three systems. Please let me know if you have any specific questions you would like to get answered.

        Thank you for your patience and for your inquiries. I believe Etta Projects truly benefited from this experience. I apologize for any previous confusion.

        Katie

        • Gilles Corcos of Agua Para la Vida (APLV)

          Dear Katie: OK, we're slowly creeping towards a convergence of views: Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds. The convergence would be more rapid if you were able to provide the information that I spe...

          Dear Katie:

          OK, we're slowly creeping towards a convergence of views:
          Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds.
          The convergence would be more rapid if you were able to provide the information that I spelled out to you as needed to calculate the pump behaviour, prominent among which is the inner diameter of that air-water tower which is essentially your tank (aside from the elasticity of your conduction line) . Is it 4", ,a foot 50cms or what? These things matter.

          Also the torque required to accelerate the pump wheels is surely not over in , or the starting torque of the pump motor is truly phenomenal - If that is what was told to you, it was a figure of speech. The rotating equivalent of F=Ma is still likely to hold.
          In addition following a previous remark by Lynn to the effect that if the air and the water in the pneumatic tower are in direct contact , some air will be entrained by the water and either manual or automatic provisions need to be made to reintroduce the air that is withdrawn. Is that part of the routine maintenance?

          You mention the flow rate of the pumps used as

          For a given pump the flow rate is given by the total head increase required- mostly the level difference between the water level in the well and the tower(level+maintained pressure in mt of water).Under these circumstances are these pumps' flow rate a 100l/m or something else?
          The relevance of that question is as follows: Whenever the pump output is less than the consumption rate of water by the village, the pump will work continuously and the available water at the end of the line will be limited by that output, (primarily). When the pump output is superior to the desired consumption rate by the population, it will start and stop frequently.
          It is likely that for each installation the parameters controlling the operation of such systems will be sufficiently different so that in each case a calculation taking all elements into account is necessary to predict performance. I just would like to make sure that it has really been the case for this project.
          Gilles

          • Gilles Corcos of Agua Para la Vida (APLV)

            PS. in the secon paragraph above, first line read

            PS. in the secon paragraph above, first line read

            • Katie Chandler of Etta Projects

              Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

              Hello Gilles,

              Thank you again for your continuous participation in this project. I appreciate your feedback.

              I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

              Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

              1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

              As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

              Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

              To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

              2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
              No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
              While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

              3. How many hours will the pump work and how often will it turn on and off?
              The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

              4. Do many star-ups turn into an extra power cost for the water operator?
              Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

              5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
              The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
              a). Manually turn off the electrical pump
              b). Open the THNs air valve
              c). Open the THNs pressure relief valve
              d). Wait for all water to come out of the THN
              e). Close both valves
              f). Turn pump on
              The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

              6. What happens if the electrical power has been cut off or a power line fails?

              Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

              I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

              Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
              Katie

              • Lynn Roberts of Agua Para La Salud (APLS)

                The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

                The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

                The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

            • Lynn Roberts of Agua Para La Salud (APLS)

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

              The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

          • Katie Chandler of Etta Projects

            Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

            Hello Gilles,

            Thank you again for your continuous participation in this project. I appreciate your feedback.

            I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

            Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

            1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

            As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

            Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

            To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

            2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
            No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
            While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

            3. How many hours will the pump work and how often will it turn on and off?
            The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

            4. Do many star-ups turn into an extra power cost for the water operator?
            Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

            5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
            The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
            a). Manually turn off the electrical pump
            b). Open the THNs air valve
            c). Open the THNs pressure relief valve
            d). Wait for all water to come out of the THN
            e). Close both valves
            f). Turn pump on
            The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

            6. What happens if the electrical power has been cut off or a power line fails?

            Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

            I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

            Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
            Katie

            • Lynn Roberts of Agua Para La Salud (APLS)

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

              The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Gilles Corcos of Agua Para la Vida (APLV)

          PS. in the secon paragraph above, first line read

          PS. in the secon paragraph above, first line read

          • Katie Chandler of Etta Projects

            Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

            Hello Gilles,

            Thank you again for your continuous participation in this project. I appreciate your feedback.

            I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

            Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

            1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

            As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

            Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

            To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

            2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
            No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
            While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

            3. How many hours will the pump work and how often will it turn on and off?
            The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

            4. Do many star-ups turn into an extra power cost for the water operator?
            Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

            5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
            The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
            a). Manually turn off the electrical pump
            b). Open the THNs air valve
            c). Open the THNs pressure relief valve
            d). Wait for all water to come out of the THN
            e). Close both valves
            f). Turn pump on
            The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

            6. What happens if the electrical power has been cut off or a power line fails?

            Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

            I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

            Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
            Katie

            • Lynn Roberts of Agua Para La Salud (APLS)

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

              The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Katie Chandler of Etta Projects

          Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

          Hello Gilles,

          Thank you again for your continuous participation in this project. I appreciate your feedback.

          I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

          Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

          1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

          As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

          Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

          To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

          2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
          No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
          While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

          3. How many hours will the pump work and how often will it turn on and off?
          The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

          4. Do many star-ups turn into an extra power cost for the water operator?
          Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

          5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
          The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
          a). Manually turn off the electrical pump
          b). Open the THNs air valve
          c). Open the THNs pressure relief valve
          d). Wait for all water to come out of the THN
          e). Close both valves
          f). Turn pump on
          The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

          6. What happens if the electrical power has been cut off or a power line fails?

          Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

          I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

          Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
          Katie

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Gilles Corcos of Agua Para la Vida (APLV)

        Dear Katie: OK, we're slowly creeping towards a convergence of views: Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds. The convergence would be more rapid if you were able to provide the information that I spe...

        Dear Katie:

        OK, we're slowly creeping towards a convergence of views:
        Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds.
        The convergence would be more rapid if you were able to provide the information that I spelled out to you as needed to calculate the pump behaviour, prominent among which is the inner diameter of that air-water tower which is essentially your tank (aside from the elasticity of your conduction line) . Is it 4", ,a foot 50cms or what? These things matter.

        Also the torque required to accelerate the pump wheels is surely not over in , or the starting torque of the pump motor is truly phenomenal - If that is what was told to you, it was a figure of speech. The rotating equivalent of F=Ma is still likely to hold.
        In addition following a previous remark by Lynn to the effect that if the air and the water in the pneumatic tower are in direct contact , some air will be entrained by the water and either manual or automatic provisions need to be made to reintroduce the air that is withdrawn. Is that part of the routine maintenance?

        You mention the flow rate of the pumps used as

        For a given pump the flow rate is given by the total head increase required- mostly the level difference between the water level in the well and the tower(level+maintained pressure in mt of water).Under these circumstances are these pumps' flow rate a 100l/m or something else?
        The relevance of that question is as follows: Whenever the pump output is less than the consumption rate of water by the village, the pump will work continuously and the available water at the end of the line will be limited by that output, (primarily). When the pump output is superior to the desired consumption rate by the population, it will start and stop frequently.
        It is likely that for each installation the parameters controlling the operation of such systems will be sufficiently different so that in each case a calculation taking all elements into account is necessary to predict performance. I just would like to make sure that it has really been the case for this project.
        Gilles

        • Gilles Corcos of Agua Para la Vida (APLV)

          PS. in the secon paragraph above, first line read

          PS. in the secon paragraph above, first line read

          • Katie Chandler of Etta Projects

            Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

            Hello Gilles,

            Thank you again for your continuous participation in this project. I appreciate your feedback.

            I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

            Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

            1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

            As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

            Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

            To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

            2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
            No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
            While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

            3. How many hours will the pump work and how often will it turn on and off?
            The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

            4. Do many star-ups turn into an extra power cost for the water operator?
            Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

            5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
            The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
            a). Manually turn off the electrical pump
            b). Open the THNs air valve
            c). Open the THNs pressure relief valve
            d). Wait for all water to come out of the THN
            e). Close both valves
            f). Turn pump on
            The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

            6. What happens if the electrical power has been cut off or a power line fails?

            Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

            I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

            Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
            Katie

            • Lynn Roberts of Agua Para La Salud (APLS)

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

              The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Katie Chandler of Etta Projects

          Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

          Hello Gilles,

          Thank you again for your continuous participation in this project. I appreciate your feedback.

          I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

          Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

          1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

          As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

          Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

          To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

          2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
          No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
          While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

          3. How many hours will the pump work and how often will it turn on and off?
          The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

          4. Do many star-ups turn into an extra power cost for the water operator?
          Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

          5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
          The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
          a). Manually turn off the electrical pump
          b). Open the THNs air valve
          c). Open the THNs pressure relief valve
          d). Wait for all water to come out of the THN
          e). Close both valves
          f). Turn pump on
          The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

          6. What happens if the electrical power has been cut off or a power line fails?

          Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

          I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

          Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
          Katie

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Gilles Corcos of Agua Para la Vida (APLV)

        PS. in the secon paragraph above, first line read

        PS. in the secon paragraph above, first line read

        • Katie Chandler of Etta Projects

          Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

          Hello Gilles,

          Thank you again for your continuous participation in this project. I appreciate your feedback.

          I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

          Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

          1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

          As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

          Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

          To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

          2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
          No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
          While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

          3. How many hours will the pump work and how often will it turn on and off?
          The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

          4. Do many star-ups turn into an extra power cost for the water operator?
          Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

          5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
          The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
          a). Manually turn off the electrical pump
          b). Open the THNs air valve
          c). Open the THNs pressure relief valve
          d). Wait for all water to come out of the THN
          e). Close both valves
          f). Turn pump on
          The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

          6. What happens if the electrical power has been cut off or a power line fails?

          Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

          I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

          Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
          Katie

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Katie Chandler of Etta Projects

        Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

        Hello Gilles,

        Thank you again for your continuous participation in this project. I appreciate your feedback.

        I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

        Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

        1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

        As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

        Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

        To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

        2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
        No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
        While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

        3. How many hours will the pump work and how often will it turn on and off?
        The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

        4. Do many star-ups turn into an extra power cost for the water operator?
        Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

        5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
        The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
        a). Manually turn off the electrical pump
        b). Open the THNs air valve
        c). Open the THNs pressure relief valve
        d). Wait for all water to come out of the THN
        e). Close both valves
        f). Turn pump on
        The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

        6. What happens if the electrical power has been cut off or a power line fails?

        Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

        I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

        Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
        Katie

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Lynn Roberts of Agua Para La Salud (APLS)

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

        The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

    • Katie Chandler of Etta Projects

      Hello! I traveled to Cochabamba last night and finally had the opportunity to meet directly with the Engineers from Plastiforte and inquire about some of your concerns related to the hydropneumatic tower. After meeting with them, I need to make some clarifications as there were obviously some miscommunications between Etta Projects’ s...

      Hello!

      I traveled to Cochabamba last night and finally had the opportunity to meet directly with the Engineers from Plastiforte and inquire about some of your concerns related to the hydropneumatic tower. After meeting with them, I need to make some clarifications as there were obviously some miscommunications between Etta Projects’ staff in Bolivia and the crew at Plastiforte. After today´s visit, I am convinced that the system is a viable system that is not only currently effectively working in many communities in Bolivia, but will also work effectively in the village Nueva America where we are proposing this project.

      In Bolivia there are three commonly used water systems: an elevated water tank, a pressure tank, and (most recently used)the hydropneumatic water tower. The main difference between the pressure tank and the hydropneumatic water tower (being proposed in the project) is that a pressure tank has a bladder that controls the amount of pressure in the system (the bladder expands and deflates with the amount of water and pressure in the system). A hydropneumatic water tower, however, uses a cylinder of air that controls the pressure inside the tower. This system was invented here in Bolivia (by a Bolivian Engineer that was trained at Georgia Tech) and has been used in Bolivia for the past 15 years. The concept is the same as the pressure tank, but instead of using a bladder it uses a cylinder (or various cylinders) that holds air pressure. The air pressure is set according to the characteristics of the village (elevation, water demand, typography, etc); for a village such as Nueva America the pressure is usually controlled between 1.4 and 2.8 bars. The system includes a manometer which shows the pressure in the system at any given time and a pressure switch that regulates the amount of pressure in the system.

      Both the hydropneumatic tower and the pressure tower preserve the quality of water and act as a single line of water distribution (large quantities of water are not being stored for later use as in an elevated tank). The advantage of the hydropneumatic tower is that there is no bladder that can rupture and that needs to be consistently changed and maintained. The hydropneumatic tower is a simpler system that carries a longer lifeline. The only part that needs to be replaced is the pressure switch. Again, this costs $30 to $50.

      The distribution system in Nueva America will uses HDPE tubing which is known for its elasticity and resistance to extreme temperatures. Our water system will be controlled between 1.4 and 2.8 bars. The optimal use of the tubing is up to 6 bars, therefore eliminating risks of bursting pipes. In reality, the tubes have a resistance of up to 15 bars.

      There are three brands of water pumps that are recommended for this system: perrollo, caprari and grudfos. All three models allow a water flow of up to 100 liters per minute. They are known for their capacity to switch on and off as many as 60 times per hour. I learned today that the system does in fact require much more frequent use of the water pump than previously reported, and I expressed our concerns about the extra energy needed to turn the pump on and off throughout the day (versus that prolonged use of filling an elevated tank). They said that the system is different than a car or large motor that takes time to reach normal use; the water pump will reach normal speed in less than a millisecond and therefore does not expend a lot of energy each time it is activated.

      After speaking with members of Plastiforte, I met with the folks from Water for People to ask why they have turned to this system over the elevated water tank. They explained various problems they had faced over the years with the elevated water tanks, including: the ability of the operator to correctly fulfill his/her daily responsibilities of filling the tank, the need to pay the operator more money for sustainability, how various untrained people turn the pump on and off when the operator is not present, the negative consequences that occur when the operator gets bored waiting for the tank to fill and forgets to shut off the pump, how there is no water in the community if the tank empties and the community waits for operator to be available to fill it, the contamination of water in the water tank (the project director said you can visibly see the difference in the quality of water between water leaving the hydropneumatic tower and a water tank), and maintenance costs to clean the tank. Rosario Villarpando Project Director from Water For People said, ¨If it´s a question of the quality of water, the cost of the system and the maintenance of the system I only see advantages to the hydropneumatic tower compared to the elevated water tank.¨ She noted that certain conditions have to be present in a village (constant electricity, a viable well) but based on her experience, she highly preferred the hydropneumatic tower to the elevated water tower. She again confirmed that the price of the electricity bills do not alter between the tank and the tower, both being around 200-250 Bs ($28-$36) monthly for as village the size of Nueva America.

      I am including some pictures of the various parts of the system in the attachment section that may be helpful. Tomorrow I am meeting again with the Engineers from Plastiforte to do a long-term cost analysis of the three systems. Please let me know if you have any specific questions you would like to get answered.

      Thank you for your patience and for your inquiries. I believe Etta Projects truly benefited from this experience. I apologize for any previous confusion.

      Katie

      • Gilles Corcos of Agua Para la Vida (APLV)

        Dear Katie: OK, we're slowly creeping towards a convergence of views: Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds. The convergence would be more rapid if you were able to provide the information that I spe...

        Dear Katie:

        OK, we're slowly creeping towards a convergence of views:
        Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds.
        The convergence would be more rapid if you were able to provide the information that I spelled out to you as needed to calculate the pump behaviour, prominent among which is the inner diameter of that air-water tower which is essentially your tank (aside from the elasticity of your conduction line) . Is it 4", ,a foot 50cms or what? These things matter.

        Also the torque required to accelerate the pump wheels is surely not over in , or the starting torque of the pump motor is truly phenomenal - If that is what was told to you, it was a figure of speech. The rotating equivalent of F=Ma is still likely to hold.
        In addition following a previous remark by Lynn to the effect that if the air and the water in the pneumatic tower are in direct contact , some air will be entrained by the water and either manual or automatic provisions need to be made to reintroduce the air that is withdrawn. Is that part of the routine maintenance?

        You mention the flow rate of the pumps used as

        For a given pump the flow rate is given by the total head increase required- mostly the level difference between the water level in the well and the tower(level+maintained pressure in mt of water).Under these circumstances are these pumps' flow rate a 100l/m or something else?
        The relevance of that question is as follows: Whenever the pump output is less than the consumption rate of water by the village, the pump will work continuously and the available water at the end of the line will be limited by that output, (primarily). When the pump output is superior to the desired consumption rate by the population, it will start and stop frequently.
        It is likely that for each installation the parameters controlling the operation of such systems will be sufficiently different so that in each case a calculation taking all elements into account is necessary to predict performance. I just would like to make sure that it has really been the case for this project.
        Gilles

        • Gilles Corcos of Agua Para la Vida (APLV)

          PS. in the secon paragraph above, first line read

          PS. in the secon paragraph above, first line read

          • Katie Chandler of Etta Projects

            Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

            Hello Gilles,

            Thank you again for your continuous participation in this project. I appreciate your feedback.

            I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

            Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

            1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

            As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

            Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

            To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

            2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
            No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
            While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

            3. How many hours will the pump work and how often will it turn on and off?
            The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

            4. Do many star-ups turn into an extra power cost for the water operator?
            Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

            5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
            The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
            a). Manually turn off the electrical pump
            b). Open the THNs air valve
            c). Open the THNs pressure relief valve
            d). Wait for all water to come out of the THN
            e). Close both valves
            f). Turn pump on
            The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

            6. What happens if the electrical power has been cut off or a power line fails?

            Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

            I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

            Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
            Katie

            • Lynn Roberts of Agua Para La Salud (APLS)

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

              The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

              The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Katie Chandler of Etta Projects

          Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

          Hello Gilles,

          Thank you again for your continuous participation in this project. I appreciate your feedback.

          I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

          Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

          1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

          As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

          Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

          To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

          2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
          No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
          While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

          3. How many hours will the pump work and how often will it turn on and off?
          The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

          4. Do many star-ups turn into an extra power cost for the water operator?
          Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

          5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
          The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
          a). Manually turn off the electrical pump
          b). Open the THNs air valve
          c). Open the THNs pressure relief valve
          d). Wait for all water to come out of the THN
          e). Close both valves
          f). Turn pump on
          The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

          6. What happens if the electrical power has been cut off or a power line fails?

          Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

          I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

          Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
          Katie

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Gilles Corcos of Agua Para la Vida (APLV)

        PS. in the secon paragraph above, first line read

        PS. in the secon paragraph above, first line read

        • Katie Chandler of Etta Projects

          Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

          Hello Gilles,

          Thank you again for your continuous participation in this project. I appreciate your feedback.

          I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

          Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

          1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

          As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

          Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

          To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

          2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
          No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
          While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

          3. How many hours will the pump work and how often will it turn on and off?
          The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

          4. Do many star-ups turn into an extra power cost for the water operator?
          Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

          5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
          The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
          a). Manually turn off the electrical pump
          b). Open the THNs air valve
          c). Open the THNs pressure relief valve
          d). Wait for all water to come out of the THN
          e). Close both valves
          f). Turn pump on
          The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

          6. What happens if the electrical power has been cut off or a power line fails?

          Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

          I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

          Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
          Katie

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Katie Chandler of Etta Projects

        Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

        Hello Gilles,

        Thank you again for your continuous participation in this project. I appreciate your feedback.

        I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

        Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

        1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

        As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

        Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

        To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

        2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
        No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
        While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

        3. How many hours will the pump work and how often will it turn on and off?
        The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

        4. Do many star-ups turn into an extra power cost for the water operator?
        Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

        5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
        The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
        a). Manually turn off the electrical pump
        b). Open the THNs air valve
        c). Open the THNs pressure relief valve
        d). Wait for all water to come out of the THN
        e). Close both valves
        f). Turn pump on
        The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

        6. What happens if the electrical power has been cut off or a power line fails?

        Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

        I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

        Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
        Katie

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Lynn Roberts of Agua Para La Salud (APLS)

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

        The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

    • Gilles Corcos of Agua Para la Vida (APLV)

      Dear Katie: OK, we're slowly creeping towards a convergence of views: Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds. The convergence would be more rapid if you were able to provide the information that I spe...

      Dear Katie:

      OK, we're slowly creeping towards a convergence of views:
      Your original suggestion of a pump cycle every week is now down to one a minute. On the basis of a guess about the diameter of your hydro tower I had come up with 20 seconds.
      The convergence would be more rapid if you were able to provide the information that I spelled out to you as needed to calculate the pump behaviour, prominent among which is the inner diameter of that air-water tower which is essentially your tank (aside from the elasticity of your conduction line) . Is it 4", ,a foot 50cms or what? These things matter.

      Also the torque required to accelerate the pump wheels is surely not over in , or the starting torque of the pump motor is truly phenomenal - If that is what was told to you, it was a figure of speech. The rotating equivalent of F=Ma is still likely to hold.
      In addition following a previous remark by Lynn to the effect that if the air and the water in the pneumatic tower are in direct contact , some air will be entrained by the water and either manual or automatic provisions need to be made to reintroduce the air that is withdrawn. Is that part of the routine maintenance?

      You mention the flow rate of the pumps used as

      For a given pump the flow rate is given by the total head increase required- mostly the level difference between the water level in the well and the tower(level+maintained pressure in mt of water).Under these circumstances are these pumps' flow rate a 100l/m or something else?
      The relevance of that question is as follows: Whenever the pump output is less than the consumption rate of water by the village, the pump will work continuously and the available water at the end of the line will be limited by that output, (primarily). When the pump output is superior to the desired consumption rate by the population, it will start and stop frequently.
      It is likely that for each installation the parameters controlling the operation of such systems will be sufficiently different so that in each case a calculation taking all elements into account is necessary to predict performance. I just would like to make sure that it has really been the case for this project.
      Gilles

      • Gilles Corcos of Agua Para la Vida (APLV)

        PS. in the secon paragraph above, first line read

        PS. in the secon paragraph above, first line read

        • Katie Chandler of Etta Projects

          Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

          Hello Gilles,

          Thank you again for your continuous participation in this project. I appreciate your feedback.

          I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

          Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

          1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

          As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

          Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

          To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

          2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
          No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
          While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

          3. How many hours will the pump work and how often will it turn on and off?
          The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

          4. Do many star-ups turn into an extra power cost for the water operator?
          Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

          5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
          The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
          a). Manually turn off the electrical pump
          b). Open the THNs air valve
          c). Open the THNs pressure relief valve
          d). Wait for all water to come out of the THN
          e). Close both valves
          f). Turn pump on
          The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

          6. What happens if the electrical power has been cut off or a power line fails?

          Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

          I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

          Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
          Katie

          • Lynn Roberts of Agua Para La Salud (APLS)

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

            The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

            The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Katie Chandler of Etta Projects

        Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

        Hello Gilles,

        Thank you again for your continuous participation in this project. I appreciate your feedback.

        I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

        Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

        1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

        As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

        Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

        To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

        2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
        No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
        While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

        3. How many hours will the pump work and how often will it turn on and off?
        The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

        4. Do many star-ups turn into an extra power cost for the water operator?
        Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

        5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
        The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
        a). Manually turn off the electrical pump
        b). Open the THNs air valve
        c). Open the THNs pressure relief valve
        d). Wait for all water to come out of the THN
        e). Close both valves
        f). Turn pump on
        The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

        6. What happens if the electrical power has been cut off or a power line fails?

        Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

        I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

        Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
        Katie

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Lynn Roberts of Agua Para La Salud (APLS)

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

        The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

    • Gilles Corcos of Agua Para la Vida (APLV)

      PS. in the secon paragraph above, first line read

      PS. in the secon paragraph above, first line read

      • Katie Chandler of Etta Projects

        Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

        Hello Gilles,

        Thank you again for your continuous participation in this project. I appreciate your feedback.

        I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

        Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

        1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

        As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

        Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

        To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

        2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
        No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
        While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

        3. How many hours will the pump work and how often will it turn on and off?
        The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

        4. Do many star-ups turn into an extra power cost for the water operator?
        Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

        5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
        The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
        a). Manually turn off the electrical pump
        b). Open the THNs air valve
        c). Open the THNs pressure relief valve
        d). Wait for all water to come out of the THN
        e). Close both valves
        f). Turn pump on
        The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

        6. What happens if the electrical power has been cut off or a power line fails?

        Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

        I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

        Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
        Katie

        • Lynn Roberts of Agua Para La Salud (APLS)

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

          The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

          The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

      • Lynn Roberts of Agua Para La Salud (APLS)

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

        The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

    • Katie Chandler of Etta Projects

      Hello Gilles, Thank you again for your continuous participation in this project. I appreciate your feedback. I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of ...

      Hello Gilles,

      Thank you again for your continuous participation in this project. I appreciate your feedback.

      I have presented many of your concerns to the Engineers at Plastiforte and together we have responded to your inquiries. I have also posted a new attachment on the project page that shows the advantages and disadvantages of each system, including a long-term cost analysis. The cost analysis was an interesting exercise. When considering the monthly depreciation cost plus the operation and maintenance cost, the hydro tower proved to be the most cost effective per household with a monthly fee of $1.50 compared to $3.70 for a elevated tank and $1.80 for a pressure tank (this is considering 40 families as in the case of Nueva America). I think this document is worth checking out. Do you feel the elevated tank is a more viable system?

      Members of Plastiforte and I read over and summarized your previous emails . Below are our responses:

      1. Do you need a water storage structure when using a THN in combination with a well and an electrical pump?

      As long as the water production capacity of the well is equal or greater than the water demand at peak time you don’t need a water tank. The aquifer acts as a natural reservoir and water is pumped directly to the network. In the case of NUEVA AMERICA, the well is able to produce 2.2 liters/second and the water demand at peak time will only be 0.5 liters/second, therefore we do not need a water storage tank.

      Conversely, when the well’s capacity is less that water demand at peak time you must pump and store water during low-demand hours (usually at night time).

      To answer your question, the cylinders have a diameter of 4 inches and are 6 meters tall; however, Plstiforte stresses not to consider this as a storage unit because the aquifer acts as a natural reservoir.

      2. When using an electrical pump in combination with a THN, does the pump start every time a tap is opened?
      No, not necessarily. The pump will start when one or more taps are open long enough so the service pressure drops to the minimum set pressure (normally around 20 psi). Once the pump starts it will replenish the pressure up to the maximum set pressure (normally around 40 psi). The THN ensures service pressure will remain within this range (20-40 psi) at all times.
      While the THN is not considered a water storage device, it acts as a pressure based flow buffer to level a variable water demand with the fixed water flow generated by the electrical pump.

      3. How many hours will the pump work and how often will it turn on and off?
      The pump will work as many hours as necessary so as to keep up with demand. The pump production time is made up of small and variable time periods. During peak demand time the pump will work for longer periods and during low-demand hours the pump will work shorter time periods. Normally the pump might start-up around 70 times per day (5-8 times per hour). It is important to use pumps that are specifically designed to start-up frequently. CAPRARI, and PEDROLLO pumps (Made in Italy) can start-up up to 60 times per hour. GRUNDFOS (made in Denmark) has has been designed for an unlimited number of start-ups per hour.

      4. Do many star-ups turn into an extra power cost for the water operator?
      Since submersible pump rotors are very small in diameter (less than 3 inches) as well as light weight (made out of light weight fiberglass), the force needed to overcome inertia is very small a well; therefore several star-ups a day do not turn into significant additional power cost.

      5. What happens if the air trapped into the THN is diluted into the water overtime and needs to be replenished?
      The operator must follow the following pressure: (Operator might need to do this once a year, especially when network is several meters above the THN level - this is not the case of NUEVA AMERICA)
      a). Manually turn off the electrical pump
      b). Open the THNs air valve
      c). Open the THNs pressure relief valve
      d). Wait for all water to come out of the THN
      e). Close both valves
      f). Turn pump on
      The operator will be trained by Plastiforte on how to identify the problem and to perform this procedure.

      6. What happens if the electrical power has been cut off or a power line fails?

      Without power the electrical pump will not work so there will be no water service on the network until power is back. Once the power is back the pump will start automatically.

      I hope this cleared up your concerns. When I think of Nueva America and this project- the well, the capacity of the pump, the water demand, and the preservation of clean water we believe this is a good choice for this village.

      Please let me know if you have any other questions. I’ve spent the last two days with the staff at Plastiforte and they are happy to work with us and respond to your concerns. Thanks again!
      Katie

      • Lynn Roberts of Agua Para La Salud (APLS)

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

        The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

        The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

    • Lynn Roberts of Agua Para La Salud (APLS)

      The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow w...

      The math for this system according to our experience in the rural setting does fit the actual situation. Our field tests indicate that in a rural village when the tap is turned on in one home the flow is about .167 L/sec to fill a 10 liter vessel with water in about 1 minute. ( we normally double this for 20 year growth in a gravity flow water system) Our peak factors tests for rural villages indicate that no more than 1/3 rd of the homes in a village will be using water at any given time during peak flow hours. If this village has 40 families then about 13 families or 13 x 0.167 = 2.17 L/sec ( 2.17 x 2 = 4.34L/sec for 20 years) would be the demand from the pump during peak flow. This also indicates that the pump will run nearly 100% of the time during peak flow hours and will steadily increase as the village grows.

      The load on the pump at start up is much more than overcoming the plastic rotor inertia. The actual load is the inertia of the rotors plus the weight of the column of water between the pump in the well and the column of water to the tower and the village.

  • Rating: 6

    review by Blue Planet Network

    The need is clearly there. But to fulfill it with an energy intensive option that:
    1) is likely more expensive to install and to operate
    2) does not meet the beneficiaries perception (they are used to water towers)
    3) makes the implementer & community dependent on technology provider
    should be questioned.

    It was not clear that a full gravity fed system was completely not feasible. And no real comparison to a traditional water tower was made.

    So i support this project, but in the context of it being a solid data provider (over time) allowing for consideration of alternatives in the future.

  • Rating: 8

    review by Gram Vikas

    The quantum of discussion has been very useful in understanding the system and we feel that this technology can provide useful feedback for similar contexts and therefore should be pursued.

  • Rating: 8

    review by Agua Para La Salud (APLS)

    The challenges to deliver water to villages as gravity water system options diminish are becoming more complicated and expensive. The situation is not only true in Bolivia, but in many parts of the world including Guatemala. The technologies ; methods of paying for the technology; and long term maintenance will be key factors in the long term sustainability of the water systems.
    This project has considered these factors and attempted to address them. The calculations for peak factor use which will ultimately impact all of these factors need to be studied in the field at length under actual use in the village since the peak factor variables do not appear reasonable for the populations served.

  • Rating: 6

    review by Agua Para la Vida (APLV)

    This project presents a technical solution which is not widely used , certainly outside of Bolivia.
    t has been presented by a representative of ETTA who was insufficiently aware of its technical aspects. Furthermore in appears that ETTA is relying on an outside vendor for these aspects. This to me has two consequences:

    1. That ETTA is not ideally situated to be responsible for the technical operation of the system- being an intermediary .
    2. That in order to evaluate the system a large number of exchanges with the ETTA representative have been necessary . The reviewers are busy folks and in spite of what the representative seems to think they spend a lot of their time looking for the cheapest solution for their water systems.

    Still the tecchnical aspects of the proposed system remain fuzzy to me. The output of the pump is in doubt since in an early comment the presenter mentioned a 1.5 HP pump and in a later comment said that a 0.75HP to 1HP pump was sufficient for the first 10 years- in any case never mentioning what the output of these pumps are around the operating point.

    That issue has its importance: Leaving aside the question of the cycling frequency, not only is the village demand over a short interval of time difficult to predict but the response of the system to that demand modifies it importantly.: Whenever the supply does not keep up with the demand the demand is often radically increased. In this respect the Bolivian official norms for village water consumption have very little relevance. Furthermore our own measurements over several similar villages have indicated that peak use rates can only be defined together with the time lapse for the measurement.

    Summary: This system will work after a fashion. But at this stage (8-17)one cannot say more.

  • Not Reviewed

    by Team Blue

  • Rating: 8

    review by Bank-On-Rain

    The hydropneumatic tower is an interesting approach to providing system pressure to many users on a single community well. I am a little unsure of how much of an improvement this system is over a conventional pressure tank, but it will be informative to track the metrics and see if it is actaully more cost-effective and easier to maintain (not much maintenance required with a pressure tank).

    Without trying new ideas we have no opportunity to incorporate systems that may improve access to safe water and improved hygiene. The pneumatic tower does not directly affect water quality, but it may facilitate more homes having access to a single well. I particularly like that this system is procured locally and not dependent upon imported equipment (other than the pumps).

Name Status Completion Date Final Cost
Construction & Implementation of Water System in Nueva America, Bolivia completed Dec 2013 12,000