Microbial Source Tracking-Driven Remediation of Recreational WatersCommunity Science/Research
Oral Presentation
Prepared by S. Esenther1, M. Pascucilla2
1 - East Shore District Health Department, 688 E Main St, Branford, CT, 06405, United States
2 - East Shore District Health Department, 688 E Main St, Branford, CT, 06405, United States
Contact Information: [email protected]; (203) 481-4233
ABSTRACT
Recreational beach closures are currently determined by simple fecal indicator bacteria thresholds. Water samples exceeding the threshold - or in some jurisdictions, precipitation levels statistically likely to correlate with exceedant bacteria levels - initiate closure of beaches or beds without providing information about the root cause of the contamination. While this simplifies routine administration procedures, it may be insufficient to provide identifying information necessary to understand patterns of fecal contamination and to direct mitigation efforts in waters with chronically poor water quality. We here provide an example of the use of microbial source tracking (MST) to identify the species source of fecal indicator bacteria from outfalls in Branford, Connecticut entering the Long Island Sound near swimming beaches. Contrary to the assumption that leaky sewage disposal systems were responsible for the high levels of contamination, we find that canine bacteria enter the waters in high concentrations at these outfalls. In response, an infrastructure and behavior change campaign was initiated that decreased canine bacterial contamination and resulted in no beach closures in 2024. As the magnitude and frequency of extreme precipitation events is anticipated to increase with climate change, coastal waters will likely face increasing bacterial contamination from precipitation-induced runoff in coming years. Use of MST and other technologies will likely become increasingly important to understand recreational beach and aquaculture water quality and protect public health in a changing climate.
