Assessment of sediment monitoring at LLNL

Three separate sediment monitoring studies have been conducted at the Lawrence Livermore National Laboratory (LLNL) Livermore site. ``Sediment`` is defined here as finely divided solid materials that have settled out of an active stream or standing water. Sediment samples from all three studies were analyzed for a number of contaminants including {sup 239}pu, {sup 3}H, gamma emitting radionuclides, heavy metals, volatile organic compounds and pesticides. The analytical results for metals and organic compounds were compared to limits for disposal of hazardous waste, the tritium values were compared to drinking water standards, and the other radionuclides were compared to soils monitoring values. No tritium values were above (or were greater than 55% of drinking water standards), and no other radionuclides in sediments were above soils values. In all of the studies, only two metals, lead and mercury, and six organic compounds, benzo(a)-pyrene, Dieldrin, p,p{prime}-DDT, Endosulfan L endosulfan sulfate, and vinyl chloride were above waste disposal limits. Three of the high contaminants, mercury, benzo(a)-pyrene, and vinyl chloride, were found at one sampling location; the others were not connected by drainage channels or physical proximity to each other. Overall, a total of 247 samples were analyzed, and the sporadic identification of materials over disposal limits demonstrates that there is negligible contamination of sediment