title: Sources and transport of contaminants of emerging concern: A two-year study of occurrence and spatiotemporal variation in a mixed land use watershed.
abstract: The occurrence and spatiotemporal variation of 26 contaminants of emerging concern (CECs) were evaluated in 68 water samples in 2011-2012 in the Zumbro River watershed, Minnesota, U.S.A. Samples were collected across a range of seasonal/hydrological conditions from four stream sites that varied in associated land use and presence of an upstream wastewater treatment plant (WWTP). Selected CECs included human/veterinary pharmaceuticals, personal care products, pesticides, phytoestrogens, and commercial/industrial compounds. Detection frequencies and concentrations varied, with atrazine, metolachlor, acetaminophen, caffeine, DEET, and trimethoprim detected in more than 70% of samples, acetochlor, mecoprop, carbamazepine, and daidzein detected in 30%-50% of samples, and 4-nonylphenol, cotinine, sulfamethoxazole, erythromycin, tylosin, and carbaryl detected in 10%-30% of samples. The remaining target CECs were not detected in water samples. Three land use-associated trends were observed for the detected CECs. Carbamazepine, 4-nonylphenol, erythromycin, sulfamethoxazole, tylosin, and carbaryl profiles were WWTP-dominated, as demonstrated by more consistent loading and significantly greater concentrations downstream of the WWTP and during low-flow seasons. In contrast, acetaminophen, trimethoprim, DEET, caffeine, cotinine, and mecoprop patterns demonstrated both seasonally-variable non-WWTP-associated and continual WWTP-associated influences. Surface water studies of CECs often target areas near WWTPs. This study suggests that several CECs often characterized as effluent-associated have additional important sources such as septic systems or land-applied biosolids. Finally, agricultural herbicide (atrazine, acetochlor, and metolachlor) profiles were strongly influenced by agricultural land use and seasonal application-runoff, evident by significantly greater concentrations and loadings at upstream sites and in early summer when application and precipitation rates are greatest. Our results indicate that CEC monitoring studies should consider a range of land uses, seasonality, and transport pathways in relation to concentrations and loadings. This knowledge can augment CEC monitoring programs to result in more accurate source, occurrence, and ecological risk characterizations, more precisely targeted mitigation initiatives, and ultimately, enhanced environmental decision-making.
authors.affiliation: University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108, United States. Electronic address: fairb109@umn.edu.
authors.forename: David J
authors.initials: DJ
authors.lastname: Fairbairn
authors.affiliation: University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108, United States.
authors.forename: M Ekrem
authors.initials: ME
authors.lastname: Karpuzcu
authors.affiliation: University of Minnesota, Civil, Environmental, and Geo-Engineering, 500 Pillsbury Drive SE, Minneapolis, MN 55455, United States.
authors.forename: William A
authors.initials: WA
authors.lastname: Arnold
authors.affiliation: University of Minnesota, Department of Soil, Water, and Climate, 1902 Dudley Ave, Saint Paul, MN 55108, United States.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Barber
authors.affiliation: University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108, United States.
authors.forename: Elizabeth F
authors.initials: EF
authors.lastname: Kaufenberg
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, 1991 Upper Buford Circle, University of Minnesota, Saint Paul, MN 55108, United States.
authors.forename: William C
authors.initials: WC
authors.lastname: Koskinen
authors.affiliation: University of Minnesota, Civil, Environmental, and Geo-Engineering, 500 Pillsbury Drive SE, Minneapolis, MN 55455, United States.
authors.forename: Paige J
authors.initials: PJ
authors.lastname: Novak
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, 1991 Upper Buford Circle, University of Minnesota, Saint Paul, MN 55108, United States.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Rice
authors.affiliation: University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108, United States.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Swackhamer
mesh_terms: D000383:Agriculture; D004784:Environmental Monitoring; D008910:Minnesota; D010575:Pesticides / Q000032:analysis; D010636:Phenols; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*; D014881:Water Supply / Q000706:statistics & numerical data*
chemical_list: D010575:Pesticides; D010636:Phenols; D062065:Wastewater; D014874:Water Pollutants, Chemical; C041594:4-nonylphenol
keywords: Agricultural; Endocrine disrupting compound (EDC); Fate transport; Pesticide; Pharmaceutical personal care product (PPCP); Urban