Technological Innovation to Remove Water Pollutants

Irrigation and precipitation runoff from agricultural fields contributes to topsoil loss and to the sedimentation of river basins. The movement of suspended soil particles from fields to streams can also serve as a transport mechanism for agricultural chemicals. These agricultural nonpoint sources of pollution (NSP) are receiving increased attention from water quality regulators. Potential actions to curb such pollutants include regulating runoff and return flows, restricting chemical applications, and imposing agricultural best management practices (BMP), such as catch-basins and tailwater recovery systems. An improved technology, Polyacrylamide polymer (PAM), may offer a cost-effective alternative for reducing the transport of chemicals on soil particles. PAM can be added to irrigation water or spread directly on fields to flocculate the suspended soil particles, causing them to settle out of the water column. This chapter explored the conditions under which the on-farm benefits (such as reduced topsoil loss, increased infiltration, reduced water use and reduced chemical use) will be sufficient to promote the adoption of PAM, and the conditions under which additional incentives may be needed to encourage innovative technological adoption.