25 August 2013

New Filter and Doser Projects in India

Since May of this year, I've been in India working with Pradan to implement AguaClara's new Low Flow Stacked Rapid Sand Filter (LFSRSF) along with our chemical doser controller (CDC) in two villages in the Khunti district in the Jharkhand state of India. There were several challenges in arriving at an efficient system from beginning to end, and we went down many suboptimal paths along the way. After more than three months, we have finally zeroed in on a sleek pilot system for AguaClara technology in the Indian village. In anticipation of successful execution, and we are preparing to implement the systems in an additional three sites immediately.

In the conceptual design stages, we cycled through many different systems that each had an element of lingering discomfort. We had to integrate the CDC and LFSRSF into the usual water supply schemes where water from a lowland well was pumped up to an elevated storage tank large enough (about 25000 liters) to serve the daily demand of about 500 people. We discarded our initial idea of using a solar pump to lift water to the LFSRSF followed by a diesel pump to lift water to the overhead storage tank, since it required the operator to manage two different pumping technologies. Then, we decided to pump water up to an extra elevated storage tank, which would then gravity feed through the treatment system. At the time, we couldn't see an efficient way to handle the huge difference in flow rate between the filter and the diesel pump. 

After fabricating the body of a 24" diameter filter, we learned that in the village of Dharaidih, Pradan had installed a solar pump that was providing nearly 1 liter per second of flow over 30 meters of height. This pump opened up new doors for a more efficient system design; it was now possible to get a high-lift pump that provided a flow rate close to that of the filter. We hit the drawing board again. The result was a design that eliminated the additional storage tank and utilized three 12" diameter LFSRSFs to handle the fluctuating flow from the solar pump.

AguaClara Water Treatment Facility. The LFSRSFs and CDC are housed above the elevated storage tank.
In addition to the LFSRSF, there has been a lot of excitement about the chemical dosers. The current chemical dosing methods involve throwing matchboxes of alum, lime, and chlorine directly into the drinking water wells. UNICEF, having a close relationship with Pradan, learned about our CDCs and was eager to have a chemical dosing option that was simple to use and enabled accurate dosing. UNICEF asked Pradan to install our chemical dosers in the remaining 18 sites where they are building government-funded overhead tank water supply systems. They are also interested in making it government policy to use our dosers for new schemes.

After extensive discussions and planning for the LFSRSF-CDC systems as well as the stand-alone CDC systems, we all agreed that filtration is a critical piece of water treatment and that we should assume filters would eventually be included in the remaining 18 sites. Now we had to balance efficiency, innovation, and standardization in deciding how to tackle the rest of the projects. For us to install efficient stand-alone CDC systems now would make for a less than elegant retrofit with filters later. Similarly, for us to install the CDCs such that the filters could easily snap into place later would make for a very inefficient dosing layout now. We also did not wish to commit to building too many filters before testing and evaluating its performance in the field. In the end, we settled on installing our filter systems in an additional 3 sites -- two villages in the Koderma district and another village in Khunti. For the remaining 15 sites, we will make an efficient but flexible chemical dosing system.
In progress mild steel model of the LFSRSF.

Pradan has shown a lot of dedication to providing water treatment to villages. They are looking to form a new Water and Sanitation "thematic group," to build up this new focus area within the organization. Additionally, they have had many meetings with the Drinking Water and Sanitation Department and build up the department's interest in deploying 50 new water treatment schemes utilizing AguaClara's LFSRSF and CDC. Through their networks and personal motivation, we are very quickly nearing a stage where we can take our systems to scale.

12 August 2013

AguaClara as Part of Integral Sanitation Project in San Nicolás, Santa Bárbara, Honduras

The week of June 17th Agua Para el Pueblo (APP) began work alongside the municipality of San Nicolás, Santa Bárbara (pop. 6500) on a multi-faceted project that will improve and secure the town’s potable water and sanitation services, and which includes the 9th AguaClara plant project in Honduras. For the first time, AguaClara is just one component of an integrated project that addresses various sanitation needs, not just the incorporation of a treatment plant into the current water system. Construction of the 32 L/s plant, which will be the first to include the AguaClara Stacked Rapid Sand Filter as part of the original design, is well under way.

History and Institutional Roles

The long-awaited treatment plant was first designed by Cornell’s design server back in March 2012, delayed due to a small overhaul of the design tool code made in an effort to include the latest innovations in what was believed to be, and ultimately did turn out to be, the next AguaClara project. APP completed the final design and budget for the plant, which included an extension of the conduction line to the proposed site, placed well above the existing storage tanks in order to expand gravity-fed service to 25 households located higher on the slope, in June 2012.

The treatment plant was first formulated as a Rotary Foundation project. The Santa Bárbara Rotary Club, with whom APP had collaborated on the Atima plant project that was finished in June 2012, would again be the local Rotary counterpart, and the Baltimore Rotary district governor Mary Anne Rishebarger was leading the effort along with AguaClara alumni to raise support among US clubs. APP was working the budget with the Santa Bárbara club and awaiting their approval.

However, the Aguasan program of the Swiss Cooperation in Central America learned of the project in late 2012 through their existing relationship with APP. The program’s area of influence encompasses much of southern Honduras, including the department of El Paraíso, where APP has collaborated with them on a successful plant project in the town of Alauca and has designed another in Morocelí. The department of Santa Bárbara is not within the Swiss Cooperation’s area of influence, but they ultimately made an exception for this project, in part because they were familiar with the impressive administration of the San Nicolás water system. They offered to contribute 67% of the budget, with the municipality covering the remaining 33%, so that the project could start as soon as the proposal was approved in Managua. The program would fund the project, however, only if the scope was expanded to include broader education programs, sanitation infrastructure, and watershed management planning.

The investment on the part of the community prior to the project’s initiation included the design/study for the treatment plant, valued at $7,100, 30% of which was paid by the water board ASANIC. The other 70% was absorbed the AguaClara program of APP/Cornell. ASANIC had also purchased the land on which the plant would be built at a cost of $3,827.

The institution responsible for carrying out the project is the municipality of San Nicolás. They will manage all funds and the purchase of materials. They will receive technical support in the form of civil engineering, certain administrative roles, and watershed management from the Associated Municipalities of the Southwest of Santa Bárbara (MUNASBAR), an association of six municipalities in the region of which San Nicolás is a member. APP plays its role in the project as a supporting implementation partner of the municipality.

Components and Goals

The water system in San Nicolás has undergone an overhaul in the past five years with a loan from the Inter-American Development Bank that was absorbed by the central government. Carried out between 2008 and 2010, the previous project included the construction of an intake structure at the source on Cerro el Volcán in the neighboring municipality of Larada, a new 16-km conduction line with a capacity of 32 L/s (500 gpm) to transport water from the source, improvements in the distribution system, and the creation of the decentralized autonomous water board ASANIC (Aguas de San Nicolás). Furthermore, a higher tariff with a tiered structure based on number of taps in each household was put in place in order to sustain the independent operation and maintenance of the water system, with an average monthly household water bill of 60 lempiras.

Increasing the tariff upon the introduction of a treatment plant into the water system that covers the costs of the operation sustainably is perhaps the most challenging and sensitive part of AguaClara projects. The starting point is often a deficient rate that does not cover the maintenance and operation costs of even the existing water system without the treatment plant, and the adjustment to make the new plant and system sustainable, now including chemicals and plant operators, can be several-fold. The San Nicolás project has the advantage that ASANIC begins with an ample income that allows them to employ an administrator and maintenance staff, maintain a challenging conduction line, and keep savings. Compared to the hike of up to 400% that the tariff has seen in other communities when the plant was introduced, the difference in San Nicolás may be more palatable. On the other hand, the average tariff will likely be higher than the starting point for any previous AguaClara plant project.

The water from the source on Cerro El Volcán in San Nicolás is not safe for human consumption, showing moderate to high turbidity in all seasons and consistent presence of fecal coliforms. The source has shown the unusual quality of producing higher-turbidity water in the dry season than in the rainy season (the hydrology hasn’t been studied, but locals speak of a snake that stirs up sediment in the cave where the water emerges when it becomes active in the summertime). In the formulation of the project, the construction of the treatment plant is not a primary goal but rather a means to an end, which is consistent filtered and disinfected water service.

A second project objective is to expand and improve water and sanitation services. One piece of this is adding piped water connections to the 25 households located above the distribution tank. This is made possible in the gravity-fed system by building the treatment plant higher on the hill than the tank, which necessitates an extension of the conduction line and substitution of 6” pipe for 8” pipe on a section of the line to maintain the same design flow rate with the higher outlet point. The other piece is sanitation infrastructure. San Nicolás has partial coverage of sewer connections. A large part of the population, however, lacks sanitary installations entirely. The project will include the construction of at least 75 latrines in neighborhoods without access to the sewer. Bathrooms in the elementary school and high school will also be renovated and installations expanded.

Infrastructure is just one component. The project also includes intervention in households and schools to improve hygiene practices. This process is guided by the ESCASAL methodology (Escuela y Casa Saludable, or Healthy School and Home), a curriculum and supporting materials developed by UNICEF and the Honduran central water and sanitation authority SANAA in the 90’s. Project personnel aim to visit 80% of homes to educate on hand washing, responsible use of water supplies, and proper use of sanitary installations. Furthermore, teachers and select students will be trained as ambassadors to lead the effort in educating and improving sanitary practices in the schools.

Finally, the project goals include the development and implementation of a watershed protection and management plan for the source on Cerro El Volcán to secure the water supply used by the municipalities of San Nicolás and San Vincente Centenario for future generations.

Progress and Timeline

The infrastructure components of the project have advanced quickly in the first five weeks. 6” pipes have been swapped out for 8” pipes on a remote 720m section of the conduction line across the valley from San Nicolás. Furthermore, the extension of the line which brings water past the distribution tank to the plant site and back again over a 470m stretch is finished. The work on the conduction line was delayed because the river which runs between the town and the section being worked on was impassable after heavy rains, which forced workers to bring water manually or by car to the construction site until last week.

The work on the plant has been sped up by the presence of foreman German Castejón and mason Kiki Rodríguez, who both worked on the Alauca and Atima AguaClara projects. While the San Nicolás plant is higher capacity and features new innovations including the Stacked Rapid Sand Filter and a re-designed sedimentation tank, their familiarity with the plant processes down to minute details has facilitated work meetings, reduced errors, and freed up time for the engineers to divide attention among other components of the project. The date for completion of the plant is February 15th, 2014. After two months of follow-up, the entire project should be finished by April 15th.

In order to measure project results, a baseline study is being carried out which surveys water system users and students on their familiarity with hygiene practices and the water system, and will collect data on sanitation installations. The ESCASAL training is now underway in its first stages, beginning last week with meetings with school teachers. The socialization of the treatment plant and higher tariff has seen progress with local television programs and meetings in the schools, health center, and individual neighborhoods. In the coming weeks ASANIC will define the tariff structure for when the plant is put into operation, in order to work with precise numbers in meetings with system users.

Training of plant operators is scheduled to begin in September. Eight candidates will be trained and narrowed down to three permanent operators during the first months of operation. APP technician Antonio Elvir, who has been involved in training AguaClara operators in the other seven plants in Honduras, will assist in San Nicolás as well.

For project photos, which will continue to be posted approximately weekly for the duration of project, visit: