A linear steady state model of the food web linking sediment to piscivorous predators was used to derive ecological risk based clean-up concentrations for mercury in sediment of East Fork Poplar Creek (EFPC), Oak Ridge, TN. The model partitions aquatic invertebrates into two classes based on the primary source of exposure to mercury in sediment, and the prey-fish community into three classes based on differences in their diets and feeding habits. Biotransfer factors for the links between sediment and sediment-dwelling invertebrates, water and aquatic biota and fish, and prey and predators are published values. The model uses site specific data on the fraction of methylmercury in sediment, the relative abundance of prey fish, and the predicted flux of mercury from sediment. Monte Carlo analysis quantifies the uncertainty in the risk to top predators of fish. At 96 mg/kg mercury in sediment, less than 20% of the exposures exceed dietary limits for endpoint receptors. The fraction of methylmercury in sediment, the three biotransfer factors for methylmercury, and diet are sensitive parameters.