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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Environmentally Integrated Dairy Management Research » Research » Publications at this Location » Publication #408170
Research Project: Managing Nutrients and Assessing Pathogen Emission Risks for Sustainable Dairy Production Systems

Location: Environmentally Integrated Dairy Management Research

Title: Des Moines water trails: health risk from waterborne pathogens during recreational water use

Author
item Burch, Tucker
item STOKDYK, JOEL - Us Geological Survey (USGS)
item FIRNSTAHL, AARON - Us Geological Survey (USGS)
item Opelt, Sarah
item Cook, Rachel
item Borchardt, Mark

Submitted to: Government Publication/Report
Publication Type: Government Publication
Publication Acceptance Date: 6/10/2024
Publication Date: 6/26/2024
Citation: Burch, T.R., Stokdyk, J.P., Firnstahl, A.D., Opelt, S.A., Cook, R.M., Borchardt, M.A. 2024. Des Moines water trails: health risk from waterborne pathogens during recreational water use. Government Publication/Report. https://www.polkcountyiowa.gov.

Interpretive Summary:

Technical Abstract: Recreational sites are being developed on waterways near Des Moines as part of the Iowa Water Trails. Waterways can be contaminated by pathogens that cause acute gastrointestinal illness (AGI) when ingested during recreation, but prevailing risk for these sites and planned activities are unknown. For six recreational sites near Des Moines, we estimated AGI risk for recreators while swimming and during limited contact activities like kayaking and fishing. Water samples (n = 147) collected over two years were tested for a variety of bacterial, viral, and protozoan pathogens using molecular methods (n = 27 assays), and AGI risk was estimated using quantitative microbial risk assessment (QMRA). Overall, AGI risk varied from < 1 to 83 AGI cases per 1,000 recreators depending on site and activity. For two sites, average swimming risk was higher than USEPA’s acceptable risk benchmark from the 2012 Recreational Water Quality Criteria (36 AGI cases per 1,000 recreators). Risk estimates for other sites and for limited contact activities were generally lower than the benchmark. Risk was examined relative to specific fecal sources (human, bovine, porcine, and avian) using microbial source tracking data, and no single fecal source dominated risk; risk was generally highest when multiple fecal sources were present. The risk of AGI was compared to the state of Iowa’s beach action value for E. coli, which is used for routine monitoring of water, and E. coli exceedances were generally more frequent than periods of elevated risk as determined by pathogen measurements and QMRA. Results inform continued development of these sites as part of the Iowa Water Trails project by characterizing the risk posed to recreators, and results provide information that can be used for risk mitigation initiatives and for managing recreators’ exposure to high-risk conditions.