Sediment and Nutrient Removal from Storm Runoff with Compost Filter Socks and Silt Fence

Compost Filter Socks, used in a variety of sediment control and storm water management applications, are being used primarily to filter sediment and other potential pollutants in storm water runoff. The objective of this study was to evaluate flow through rates and sediment and nutrient removal or loss capability of these newly developed sediment control devices. Five experimental treatments were replicated in triplicate: three filter sock treatments, silt fence (24 in.) and control (no sediment control). The treatments were installed in large chambers (110 cm x 35 cm x 25 cm), to roughly simulate the field conditions, with 2 to 3 inches of silt loam soil. Chambers were adjusted on the rain simulated table to have a 10% slope. A rainfall simulation system was used to provide 3 inches/hour of rainfall intensity for 0.5 hr duration on the respective chamber treatments. Runoff samples were taken at the base of the soil chamber immediately after overland flow runoff passing through the treatment. Samples were quantified for turbidity, total solids, total N, ammonium N, nitrate + nitrite N, and total P and dissolved reactive P concentrations. Direct water balance measurements included total rainfall and total runoff. Flow rates from the filter socks averaged 50%