M2 PM Non-Point Source Pollution and TMDLs
Monday, 14 November 2005: 1:50 PM - 5:30 PM in Ballroom 2

(LET-1117-815179) Point versus non-point sources and fate of major PPCPs and herbicides in the Detroit River: Wasterwater effluent to surface water to drinking water.

Letcher, R.^{1, 2}, Hua, W.², Bennett, E.², Metcalfe, C.³, ¹ Environment Canada, Canadian Wildlife Service, National Wildlife Research Centre, Ottawa, Ontario, Canada² University of Windsor, Great Lakes Institute for Environmental Research, Windsor, Ontario, Canada³ Trent University, Water Quality Centre, Peterborough, Ontario, Canada

ABSTRACT- Pharmaceuticals (PhACs) and personal care products are collectively referred to as PPCPs, and are used in considerable quantities for, e.g. therapeutic, clinical and disease alleviation purposes by humans and in veterinary science. Triclosan (5-chloro-2-(2,4-dichlorophenoxy) phenol) is a broad-spectrum antibacterial and used heavily as an antimicrobial agent. The Detroit River passes through one of the most densely populated areas in the Great Lakes basin, accepting significant urban/agricultural runoff and wastewater (WSTP) discharge from the U.S and Canadian sides. Surface water of the upper Detroit River is also the important source of drinking water for the surrounding urban complex. We report on point versus non-point source input, fate, drinking water treatment effects and annual variations of seventeen major PhACs, triclosan and the herbicide class of chloro-s-triazines (atrazine), in waters from the Canadian side of the upper Detroit River. Fifteen out of seventeen PhACs, triclosan and atrazine were detected in all WSTP effluent samples, and concentrations were highly variable (1.7 to 1244 ng/L) for three annual sampling periods. A reduction of >90% for all concentrations was found in surface waters from shoreline sites along the Canadian side of the upper Detroit River. For PhACs and triclosan, large-scale dilution upon entering river waters occurs from point source inputs from WSTPs. This was not true for atrazine, where surface water concentrations were higher than in WSTP effluent. Regardless of the season of sampling, and despite large scale dilution, trimethoprim, caffeine, carbamazepine and cotinine were consistently measurable at sites downstream of the Detroit River/Little River confluence. Only atrazine carbamazepine, cotinine and caffeine were quantifiable with any frequency near the raw water intake for City of Windsor, drinking water treatment facility. For these PhACs and atrazine, conventional treatment processes that included ozonation had a dramatic reductive effect on water concentrations, whereas conventional treatment alone had a more minor reductive effect.

Key words: PPCPs, atrazines, water, Detroit River