Cleaner Runoff

Cleaner Runoff. I'm Greg Martin with today's Line On Agriculture. Water is the very lifeblood of our world. Water that runs off of the land can quickly pick up any number of contaminants spreading them from place to place and eventually ending up in our streams, lakes and oceans. Now a collaboration between two groups may have a solution to part of this problem. Northwest Ag's Lacy Gray has more. Agricultural Research Service scientists and researchers from Filtrexx International have improved on an existing method for removing contaminants from storm water runoff. These findings could provide surface waters additional protection against runoff containing pollutants from point sources such as construction sites, storm waters and other urban landscapes. "Filter socks" containing compost tucked into mesh tubes are used to capture some of the silt, heavy metals, fertilizers and petroleum products washed from compacted surface areas into nearby streams and rivers. Wastewater treatment plants use flocculation agents to help sediments and pollutants form clumps large enough to be filtered out of the water, even when the substances are in a dissolved state. The team added flocculation agents to compost socks and then ran laboratory tests to see how well the socks trapped sediment, coliforms, nitrates, E. coli bacteria, heavy metals and petroleum products in runoff after simulated "rain events." The scientists found that compost socks alone removed the majority of clay and silt particles that contribute to suspended solids in surface waters. The socks also removed 17 percent of ammonium nitrogen, 75 percent of E. coli bacteria, and from 37 percent to 72 percent of the heavy metals. In addition, runoff levels of diesel fuel dropped 99 percent, levels of motor oil dropped 84 percent, and gasoline levels dropped 43 percent. However, socks with flocculation agents removed even more of the pollutants from runoff, including 27 percent of the ammonium nitrogen, 99 percent of E. coli bacteria, 99 percent of the motor oil, 54 percent of the gasoline and from 47 percent to 74 percent of the heavy metals. Results from this research were published in the Journal of Environmental Quality. For more information be sure and visit the ARS website at www.ars.usda.gov. That's today's Line On Agriculture. I'm Greg Martin on the Ag Information Network.