Assessment of Health Risks Associated with Wastewater Treatment During Extreme Precipitation events from a Great Lakes Region Case Study

Introduction: Climate variability including changes in the frequency of high precipitation events is stressing the already taxed wastewater infrastructure in the United States and Canada. During periods of intense rainfall, stormwater runoff into wastewater treatment facilities can exceed treatment capacities as well as impact treatment performance, resulting in sewage spills, blending events, and an increase in public health risks. The frequency of heavy precipitation events in the Great Lakes region has increased in recent years and is projected to increase in the future.The wastewater industry will need to make major investments in related infrastructure to protect public health during the next 10-20 years. A quantitative analysis of related infrastructure failure risks and subsequent human health risks is needed to help guide the wastewater industry. Our overall goal is to assist the wastewater industry in quantifying climate- and health-related risks through the proposed project gathering and analyzing data linking treatment technology, efficacy, and water quality with heavy precipitation events. This will provide the industry with the knowledge needed for decision-making at the community level for appropriate investment to protect water quality and health now and in the future.

Specific Goals and Outcomes: There are three major objectives in our two-year project: 1) Development of a wastewater quality sampling system to help determine links between causal precipitation events, treatment system technologies, and water quality; 2) An analysis of heavy precipitation event frequency and wastewater quality impacts including quantitative microbial risk assessment (QMRA) over historical and projected future time frames; and 3) Development of a meaningful and actionable climate-related information resource that can be shared interactively with the wastewater industry to assist with management-related decisions on infrastructure and planning. Our proposed project domain is the southeastern one-quarter of Michigan’s Lower Peninsula, an area which includes some of the most stressed fresh water systems in the world. Outcomes will advance the resilience of wastewater/stormwater management across the region and the science of knowledge usability.

Significance and Broader Impacts: This proposal couples NOAA’s mission of “Science, Service, and Stewardship” to IRAP’s focus to “link science and assessments to practice risk management challenges in regions where weather and climate affect U.S. interests at home and abroad.” Byactively co-producing climate information with end-users to address near- and long term risks facing stormwater-impacted treatment systems and associated public health risks, we will both increase partnerships between academia and local governments and enhance the uptake and use of knowledge produced and supported by NOAA.