Clean Water from the Rainforest

December 17, 2008

How do you bring fresh spring water to families in a remote community of high-elevation coffee farmers? Answer: with concrete, rebar, sand, lime, hacksaws, piping (galvanized and PCV) and a slew of other tools and materials, all transported by rickety rigs on bad roads.

In the summer of 2008, a team of OSU undergraduates led by Water Resources Engineering Ph.D. student Kelly Kibler built a gravity-fed water delivery system in the Salvadoran community of Las Mercedes. Hand-in-hand with local tradesmen, the Engineers Without Borders teams began by building a collection network - an "infiltration gallery" - of perforated PVC piping, overlain by gravel and sand to trap sediment and debris at the water source.

diagram

From there, they dug trenches and laid nearly 4,000 feet of pipe across steep, densely vegetated slopes. Air-release valves were located at intervals along the way to ensure proper flow, which the engineers estimated at a maximum of about 1.5 gallons per minute (the equivalent of a low-flow showerhead). To store the water, they built two cinder-block storage tanks on concrete slabs, providing five families with easy access.

"Since we left," Kibler says, "we've gotten word that the system is functioning as planned."