The primary goal of this study was to assess the presence or absence of organic chemicals originating from pharmaceutical and personal care products in ambient waters in the study areas. These contaminants are collectively called contaminants of emerging concern (CECs) to distinguish them from more conventional pollutants.  A secondary goal was to describe the relative magnitude of the detected CECs. A total of 51 samples were collected across multiple depths within the three study areas and were analyzed for 140 CECs.

Results show that 26 different CECs were detected out of the 140 that were analyzed.  The type 2 diabetes drug Metformin had the highest concentrations (up to 786 ng/L) and a high frequency of detection (27 of 51 samples, or 52.9 percent). Caffeine and sulfamethoxazole (an antibiotic) were also commonly detected in 25 (50 percent) and 28 (55 percent) of 51 samples, respectively.  The most commonly detected CEC was benzoylecgonine (the metabolite of cocaine), which was found in 48 of 51 samples (94.1 percent).