Operation of AguaClara's twelfth water treatment plant in Honduras began in the last week of September, 2015. The plant treats 14 L/s and serves about 700 households spread across four communities in the department of El Paraíso: San Matías, Robledal, Corral Falso, and San Francisco. Six operator candidates have been operating the plant for the past few weeks under the supervision of an AguaClara technician and engineer from Agua Para el Pueblo. They will be supervised for two months as a practical training period, after which the local water board will select three of them to be permanent operators.
The San Matías plant includes a number of innovations. The most visibly obvious is an elevated entrance tank which stores a reserve of water used to increase the flow through the plant when the operator needs to backwash the filter during the dry season. The reserve has already been tested successfully several times, and backwash frequency has been estimated at 30 hours. However, this value was estimated during a period of high influent turbidity, and will be less frequent during periods of low influent turbidity and as operators refine their coagulant dosing.
Another innovation hidden in the sand bend of the stacked rapid sand filter is a new injection system. Instead of the expensive, imported, easily-clogged slotted pipes used as previous entrance module branches, the new branches have orifices and wings which were fabricated locally by plant operators. The orifices cannot be clogged, and the wings prevent sand reentry during a brief period of back-flow at the end of the backwash cycle. Researchers at Cornell are working on a similar extraction system to eliminate the use of slotted pipes in the filter altogether.
The communities served by the plant have shown a strong commitment to its success, adopting a household monthly water tariff of 100 lempiras (about $5) - the highest water tariff of any community served by an AguaClara plant to date. Roughly half of this tariff will cover the expenses of the plant (operator salaries and chemicals), while the other half will cover general maintenance expenses for the network and plumber and accountant salaries. Considering that families often spend 200 lempiras a month on bottled water, our plant is going to provide a lot of savings!