Temporal Variation of Mercury in Effluent from Two Municipal Wastewater-Treatment Plants in Southwest Ohio

Wastewater-treatment plants (WWTPs) are an important source of mercury (Hg) to surface waters, but little is known about temporal variability of efflux to aquatic systems. We found that Hg concentrations in effluent varied by about a factor of 2 on monthly, weekly, and hourly timescale comparisons. These results suggest that limited sampling can yield a representative concentration with reasonable uncertainty for purposes of estimating the environmental significance of Hg from WWTPs. Environ Toxicol Chem 2020;39:1027-1031. © 2020 SETAC.