Sites C, D, E, and F are located in the Salt Slough/Mud Slough system. Site C is located in Mud Slough upstream of the inflow from the SLD, and was selected for this reason. Site D is downstream of the SLD inflow. Influence of drain inflows, presence of a USGS gauging station, and an existing data base of sediment and water chemistry, were rationales for choosing this site. Site E is located on Mud Slough at Highway 140. A previous sampling site near this location was abandoned due to flooding and subsequent inaccessibility. Site F is located in Salt Slough near Highway 165.