Samples at stations in the SLD will consist of three composite samples per sampling location using a precise volume detritus and bed sediment sampler developed by LBNL (Quinn and Clyde, 1996). One sample will be zero to three centimeters, another three to eight centimeters, and the third, greater than eight centimeters. At sampling sites in the sloughs, only the first two depth intervals are collected. During the first sampling episode, both discrete and composite samples will be taken for comparison purposes. The discrete samples will be taken from the left and right sides of the drain or slough. Composite samples will be taken from both right and left, as well as center point sample locations. Care will be taken when sampling to insure that the actual bottom of the drain is sampled rather than the side slope. Where the thickness of bed sediment in the SLD is greater than 30 cm, a push tube sampler with an expandable end plug will be used.