A method for removing contaminants from storm water runoff has been developed by a team of scientists.
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.
Agricultural Research Service (ARS) scientists Eton Codling, microbiologist Dan Shelton and soil scientists Yakov Pachepsky and Ali Sadeghi, and their collaborators Britt Faucette and Fatima Cardoso-Gendreau have created 'filter socks'.
"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.
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 socks with flocculation agents removed27 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.