Sediment samples were collected from mercury-contaminated streams and lakes in Texas, Virginia, and Tennessee and were analyzed for total carbon (TC) and total nitrogen (TN). A portion of the sample was combusted at 550 degrees C for 2 hours prior to analysis to remove the organic carbon and nitrogen, thus giving total inorganic carbon (TIC) and total inorganic nitrogen (TIN). Total organic carbon (TOC) and total organic nitrogen (TON) were calculated from these values.