EPA Research Partner Support Story: Obtaining water quality data to inform processing and treating stormwater reuse

Partners: Minnesota Department of Health; University of Minnesota
Challenge: Obtaining water quality data and best technologies for informing processing and treating stormwater reuse
Resource: Water quality assessments of stormwater harvested for landscaping and agricultural irrigation near four midwestern towns
Project Period: 2019 – 2020

There is limited data to determine the suitability of stormwater for direct reuse in surface irrigation systems, either on a commercial or residential scale. In locations with limited infiltration capacity or stressed water supplies, water reuse can conserve resources and benefit surface water quality. However, it is also important to ensure that reuse projects are implemented in ways that protect human health and the environment.

“This project will help Minnesota to keep moving forward with stormwater reuse as a tool to conserve water resources and improve surface water quality while protecting public health.” – Minnesota Department of Health, Engineer Anita Anderson

EPA ORD, in collaboration with the Region 5 (Great Lakes) and the Minnesota Department of Health, planned and implemented stormwater sampling events to determine water quality impacts on irrigation and agricultural stormwater reuse. Specifically, stormwater samples were collected in Chicago, IL; Cincinnati, OH; Cleveland, OH; and Minneapolis, MN, in August 2019 for physical, chemical and microbial indicators and in October 2020 for pathogen samples. Samples were collected from various collection areas including 1) rooftop water collection tanks, 2) permeable pavement catch basins, 3) mixed use (roofs, parking lots) urban underground cisterns and storage tanks, and 4) mixed use (roofs, vegetated lands) suburban ponds and farm wetlands. Reuse site characteristics of interest include age, tributary area, land use, end-use of water, size and type of storage, and type of treatment (e.g., sediment screens, filtration, chlorination, ultraviolet disinfection). 

The research provided relevant information on the extent of physical, chemical and microbial contamination of reuse waters and the effectiveness of filtration and disinfection technologies to reduce public health risks.