Publication Summary

In August 2008, the Washington State Department of Ecology and the U.S. Environmental Protection Agency conducted a screening study to characterize pharmaceuticals and personal care products (PPCPs) in municipal wastewater treatment plants (WWTPs). Samples of influent (untreated), effluent (treated), reclaimed water, and biosolids were analyzed from five WWTPs in the Pacific Northwest. The treatment technologies ranged from secondary processes such as activated sludge to advanced nutrient removal and tertiary filtration. Target analytes included PPCPs, hormones, steroids, semi-volatile organic chemicals, nutrients, and total suspended solids. Overall, the study results indicate that advanced nutrient reduction and tertiary filtration provide additional benefits for PPCP removal.

In August 2008, the Washington State Department of Ecology (Ecology) and the U.S. Environmental Protection Agency (EPA) conducted a one-day screening study to characterize pharmaceuticals and personal care products (PPCPs) at five municipal wastewater treatment plants (WWTPs) in the Pacific Northwest. Wastewater influent, secondary effluent, tertiary effluent, and biosolids were sampled.

Four of the five WWTPs discharge within the Puget Sound watershed. Two of the plants provide secondary treatment, and three employ advanced (tertiary) treatment for nitrogen and phosphorus removal. Two of the plants produce tertiary-treated reclaimed water.

Target analytes included 172 organic compounds (PPCPs, hormones, steroids, semi-volatile organics). In addition, nutrients and total suspended solids were sampled. Newly approved EPA methods were used to measure PPCPs, hormones, and steroids at low concentrations. Removal efficiencies were evaluated for each analyte at the five WWTPs.

In the study, PPCPs were found in all samples at concentrations comparable to those found in the literature. Secondary treatment alone achieved high removals for hormones and steroids. Approximately 21% of the 172 analytes were reduced to below reporting limits by conventional secondary treatment, whereas 53% were reduced to below reporting limits by at least one advanced nutrient-removal technology.

Roughly 20% of the 172 analytes (mainly polycyclic aromatic hydrocarbons) were found only in the biosolids and not the wastewater samples. Some analytes were clearly concentrating in the biosolids.

Three PPCPs (carbamazepine, fluoxetine, and thiabendazole) were relatively untreated by the surveyed WWTP technologies. These three PPCPs may serve well as human-influence tracer compounds in the environment.

Overall, this screening study indicates that (1) there are differences in PPCP removal between the WWTP processes and (2) advanced nutrient reduction and tertiary filtration may provide additional PPCP removal.

Link to EIM data for User Study ID BRWA0005