In reply to Ma!.

The water comes from a community tank, when it's not the dry season (for groundwater). At other times, they install a gutter to catch rainwater. The soapy water just runs out into the field. This brings up the fifth technology we are promoting, one that is not even on the radar for around here: sumideros (sumps). It's basically a sand filter pit. We haven't even tried to push this; it is a great health benefit, since it keeps the water source clean, but it's an even harder concept to understand than a concrete floor keeping parasites at bay.