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Effects-based monitoring of bioactive contaminants discharged to the Colorado River before and after upgrades to a municipal wastewater treatment facility
Citation:
Cavallin, J., W. Battaglin, J. Beihoffer, B. Blackwell, P. Bradley, A. Cole, D. Ekman, J. Kinsey, K. Keteles, R. Weissinger, D. Winkelman, AND D. Villeneuve. Effects-based monitoring of bioactive contaminants discharged to the Colorado River before and after upgrades to a municipal wastewater treatment facility. SETAC North America, Toronto, ON, CANADA, November 03 - 07, 2019.
Impact/Purpose:
The lack of established water quality criteria or guidelines for many contaminants of emerging concern (CECs) in surface waters represents a significant challenge to state and regional risk assessors charged with protecting our nations waters and associated aquatic ecosystems from harmful impacts of toxic chemicals. For example, recent contaminant and biological effects surveillance on the South Platte and Colorado rivers in Region 8 have detected complex mixtures of contaminants and estrogen receptor (ER), glucocorticoid receptor (GR), and peroxisome proliferator activated receptor (PPAR)-mediated biological activities in surface waters downstream of municipal waste-water treatments plants (WWTP). Their spatial and temporal variation in relation to discharge and flows, potential hazards to resident aquatic organisms, and whether adverse biological effects are occurring, are unknown. Environmental surveillance and monitoring approaches capable of detecting sublethal impacts of chemical contaminants in complex mixtures before they manifest into ecosystem-level impairments, are needed. Furthermore, approaches that provide the ability to relate these effects to potential causative agents and sources are critical for enabling Regional Offices to meet their mandates. The present RARE project (#2100) builds upon several years of preliminary chemical monitoring research on the Colorado River as a basis for further investigation of ER, GR, and PPAR-bioactive contaminants and potential responses elicited in caged fish.
Description:
The present study highlights the utility of bioeffects-based monitoring in conjunction with analytical chemical measurements of surface waters on the Colorado River associated with a historically bioactive wastewater treatment plant effluent. Concurrent with chemical monitoring and in vitro bioactivity measurements, in situ caged fish systems were employed to evaluate the potential bioavailability of predicted biologically-active contaminants associated with ER, GR, and PPAR-associated activities. The present study compares the effects of a wastewater treatment plant facility upgrade on bioactive contaminant loading. Abstract:Recent monitoring of surface water from the Colorado River near the wastewater treatment plant (WWTP) outfall in Moab, UT, detected chemicals of emerging concern and estrogen-receptor (ER)-, glucocorticoid receptor (GR)-, and peroxisome proliferator activated receptor-gamma (PPAR)-mediated biological activities. In 2018, the Moab WWTP was modernized and upgraded to accommodate the increased influent associated with tourism in the area. The present, multi-year study aimed to determine whether the plant upgrade reduced bioactive contaminant loading and if so, over what geographic area relative to the discharge site. Water samples were collected bimonthly, pre- and post-upgrade, at 10 sites along the CO River, upstream and downstream of the Moab WWTP. Water samples were analyzed for in vitro biological activities (e.g., ER, GR, and PPAR). To evaluate the potential in vivo bioavailability of contaminants and potential impacts of the WWTP upgrade, adult fathead minnows were caged at five or six sites at various proximities to the WWTP pre- (2018) and post- (2019) upgrade. After four days of exposure, muscle, livers, gonads, and brains were collected for measurement of targeted gene expression. An autosampler was simultaneously deployed at each site to collect a composite water sample representative of the fish exposure. Composite water samples were analyzed for a suite of pharmaceuticals, pesticides, steroid hormones, wastewater indicators, and in vitro biological activities. Prior to the WWTP upgrade, in vitro ER, GR, and PPAR activities were associated with the surface water at the WWTP outfall site, but activities rapidly diminished with downstream dilution. Based on bioanalytical equivalents, estrone and estriol (38 and 66 ng/L) were the prominent drivers of in vitro ER activity at the WWTP site. No dramatic responses were observed in ER-, GR-, and PPAR-related gene expression in male livers of caged fish prior to the facility upgrade; however, 100% mortality was observed at the WWTP site, likely due to ammonia toxicity (0.91 mg NH3/L measured in the composite sample). No treatment-related mortalities were observed in the post-upgrade fish exposure. Results from 2018 and 2019 will be compared to evaluate effects of the upgrade on ER, GR, and PPAR-related bioactive contaminant loading.