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The sediment, water, and three species of fish from 24 of Massachusetts' (relatively) least‐impacted water bodies were sampled to determine the patterns of variation in edible tissue mercury concentrations and the relationships of these patterns to characteristics of the water, sediment, and water bodies (lake, wetland, and watershed areas). Sampling was apportioned among three different ecological subregions and among lakes of differing trophic status. We sought to partition the variance to discover if these broadly defined concepts are suitable predictors of mercury levels in fish. Average muscle mercury concentrations were 0.15 mg/kg wet weight in the bottom‐feeding brown bullheads (Ameiurus nebulosus) (range = 0.01–0.79 mg/kg); 0.31 mg/kg in the omnivorous yellow perch (Perca flavescens) (range = 0.01–0.75 mg/kg); and 0.39 mg/kg in the predaceous largemouth bass (Micropterus salmoides) (range = 0.05–1.1 mg/kg). Statistically significant differences in fish mercury concentrations between ecological subregions in Massachusetts, USA, existed only in yellow perch. The productivity level of the lakes (as deduced from Carlson's Trophic Status Index) was not a strong predictor of tissue mercury concentrations in any species. pH was a highly (inversely) correlated environmental variable with yellow perch and brown bullhead tissue mercury. Largemouth bass tissue mercury concentrations were most highly correlated with the weight of the fish (+), lake size (+), and source area sizes (+). Properties of individual lakes appear more important for determining fish tissue mercury concentrations than do small‐scale ecoregional differences. Species that show major mercury variation with size or trophic level may not be good choices for use in evaluating the importance of environmental variables.

Corrosion, even in water supply systems with treatment to reduce it, can be a major contributor of copper and lead to both treated municipal (publicly owned treatment works, POTW) wastewater effluents and biosolids. Lead and copper concentrations were measured at several points in the water/wastewater systems of four Massachusetts municipalities. Domestic wastewater was found to contain concentrations of lead and copper significantly higher (p < 0.05) than those in source waters. For each facility, the median concentration of Cu in domestic wastewater was a substantial fraction of the median concentration found in the influent to the POTWs with ratios of 0.36, 0.41, 0.65, and 1.25 for Gardner, New Bedford, Fall River, and Clinton, respectively. The values for lead, in the same order, were 0.28, 0.19, 0.17, and 0.69 (this last ratio based on mean values). Data from the study indicate that minimizing influent concentrations of Cu and Pb to POTWs is an important control factor since the finding of constant removal efficiency for these two constituents means that the higher their concentrations in the influent, the higher they will be in the effluent. These observations strongly support the concern that corrosive drinking water contributes substantially to exceeding, at a minimum, water quality criteria for copper, where dilution of wastewater effluents is low. In turn, this argues for corrosion reduction efforts in water supply systems and the means by which such controls are effected to consider impacts on wastewater as well, which generally is not now done.