Modifications To Improve Sediment Pond Performance (073a2ef3-724f-4100-81cc-836f3c56b373)

Three sedimentation ponds had their performance evaluated before and after installation of modifications. Each pond had a floating baffle installed, two had siphon outlets and one had a floating outlet device. Baffles inhibited short circuiting, and the outlet devices retarded flow following a rainfall event, and drained the pond creating a large storage volume to maximize detention time. Total suspended solids and settleable solids tests were run on samples of influent and effluent to evaluate pond performance. Particle size analyses were run on samples containing measurable amounts of solids. Performance improved in each pond, with baffles providing the major improvement. Through the entire surface mining process un- protected soil is exposed to direct rainfall and subject to accelerated erosion. Without controls, receiving streams would be "choked" by the additional sediment load. Several states, including West Virginia, require that sediment control ponds be constructed to trap the sediment before the water enters receiving streams. Even well designed ponds have exhibited difficulty in meeting effluent limitations. In a study supported by EPA, about half the ponds did not meet effluent limitations (1). There is a critical need to reduce sediment losses using presediment pond controls or by improving sediment pond performance. The objectives of this study were to evaluate modifications designed to improve sediment pond performance by; 1) monitoring three ponds prior to modification, 2) install floating baffles and 3) modify the principle spillway and determine the change in pond performance.