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ARS Home » Midwest Area » St. Paul, Minnesota » Soil and Water Management Research » Research » Publications at this Location » Publication #321112
Title: Contaminants of emerging concern: Mass balance and comparison of wastewater effluent and upstream sources in a mixed-use watershed

Author
item FAIRBAIRN, DAVID - University Of Minnesota
item ARNOLD, WILLIAM - University Of Minnesota
item BARBER, BRIAN - University Of Minnesota
item KAUFENBERG, ELIZABETH - University Of Minnesota
item KOSKINEN, WILLIAM - Retired ARS Employee
item NOVAK, PAIGE - University Of Minnesota
item Rice, Pamela
item SWACKHAMER, DEBORAH - University Of Minnesota

Submitted to: Environmental Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/2015
Publication Date: 1/5/2016
Citation: Fairbairn, D., Arnold, W., Barber, B., Kaufenberg, E., Koskinen, W.C., Novak, P., Rice, P.J., Swackhamer, D. 2016. Contaminants of emerging concern: Mass balance and comparison of wastewater effluent and upstream sources in a mixed-use watershed. Environmental Science and Technology. 50(1):36-45. doi: 10.1021/acs.est.5b03109.

Interpretive Summary: Understanding the sources, transport, and spatiotemporal variability of contaminants of emerging concern is important for understanding risks and developing monitoring and mitigation strategies. This study compared contaminants of emerging concern loading and transport from a wastewater treatment plant and upstream areas in a mixed-use watershed in Minnesota, USA, under different seasonal and hydrological conditions. Mass balances were used to characterize the sources, loadings, and variability of sixteen contaminants of emerging concerns. Three distinct contaminants of emerging concern groups emerged with respect to their total loading and source proportionality. Agricultural herbicides and daidzein inputs were primarily by upstream routes and their loadings and concentrations were greatest during high flows. Trimethoprim, mecoprop, non-prescription pharmaceuticals, and personal care products entered the system by balanced/mixed pathways with peak loadings and concentrations in high flows. Carbaryl, 4-nonylphenol, and the remaining prescription pharmaceuticals entered the system by wastewater treatment plant outflow. Loadings of the outflow-dominated pharmaceuticals were relatively stable across sampling events. Mass balance analysis based on multiple sampling events and sites facilitate contaminants of emerging concern source comparison and can be used to identify appropriate mitigation strategies. For example contaminants of emerging concerns identified as primarily effluent-associated contaminants would trigger wastewater treatment plant based mitigation while agricultural herbicides that were predominantly a result of upstream sources would trigger a need for agricultural and storm water best management practices to prevent mobilization and promote attenuation of contaminants of emerging concerns through filtration, sorption, and biodegradation. These practices may be useful in concert with increasingly proposed contaminants of emerging concern source reductions and wastewater treatment plant based mitigation strategies, especially in mixed-use areas where additional sources, high-flow events, and runoff components are likely to be important.

Technical Abstract: Understanding the sources, transport, and spatiotemporal variability of contaminants of emerging concern (CECs) is important for understanding risks and developing monitoring and mitigation strategies. This study compared CEC loading and transport from a wastewater treatment plant and upstream areas in a mixed-use watershed in Minnesota, USA, under different seasonal and hydrological conditions. Mass balances were used to characterize the sources, loadings, and variability of sixteen CECs. Three distinct CEC groups emerged with respect to their total loading and source proportionality. Agricultural herbicides and daidzein inputs were primarily by upstream routes and their loadings and concentrations were greatest during high flows. Trimethoprim, mecoprop, non-prescription pharmaceuticals, and personal care products entered the system by balanced/mixed pathways with peak loadings and concentrations in high flows. Carbaryl, 4-nonylphenol, and the remaining prescription pharmaceuticals entered the system by wastewater treatment plant effluent. Loadings of the effluent-dominated pharmaceuticals were relatively stable across sampling events. Mass balance analysis based on multiple sampling events and sites facilitated CEC source comparison, which can be used in the exploration of appropriate mitigation strategies.