December 8, 2008—The US Environmental Protection Agency (EPA) is seeking comments on its proposed guidelines to control the discharge of pollutants from construction sites. The Proposed Effluent Guidelines would require all construction sites to implement erosion and sediment control best management practices to reduce pollutants in stormwater discharges.
In addition, for certain large sites located in areas of the country with high rainfall intensity and soils with a high clay content, stormwater discharges from the construction site would be required to meet a numeric limit on the allowable level of turbidity, which is a measure of sediment in the water. In order to meet the proposed numeric turbidity limit, many sites would need to treat and filter their stormwater discharges.
Construction activities such as clearing, excavating, and grading significantly disturb the land, explains EPA. The disturbed soil, if not managed properly, can easily be washed off the construction site during storms and enter streams, lakes, and other waters.
Sediment is one of the leading causes of water quality impairment nationwide, including reducing water depth in small streams, lakes, and reservoirs, adds EPA. Stormwater discharges from construction activities can reportedly cause an array of physical, chemical, and biological impacts.
