A barrel for recycling rainwater. Photo credit: Shutterstock Droughts and major water shortages are leading parts of the U.S. to turn to alternative water sources such as graywater and stormwater. Graywater is untreated wastewater from bathroom sinks, showers, tubs, washers, and laundry sinks, and stormwater is runoff from rainfall or snowmelt from roofs, parking areas, and land surfaces.
But before either can be used safely, guidelines and research are needed on their risk to public health and the environment, according to a new 420-page report from the National Academies of Sciences, Engineering, and Medicine (NAS). The publication, “Using Graywater and Stormwater to Enhance Local Water Supplies: An Assessment of Risks, Costs, and Benefits,” was written in part by Robert Raucher of Abt Associates, a member of the NAS Committee on the On-Site Reuse of Graywater and Stormwater.
Graywater and stormwater could significantly supplement traditional potable water supplies using existing capture and treatment technology, but limited information exists on the costs, benefits, risks, and regulation of such projects, the report concludes. Additional research and changes in infrastructure will be necessary to take full advantage of the potential of graywater and stormwater.
One line of research should focus on the types and concentrations of pathogens that are likely to occur in stormwater and graywater, the report says. Additional information is also needed on the organic chemicals in stormwater and their consequences for various uses.
Read the full report:
Using Graywater and Stormwater to Enhance Local Water Supplies: An Assessment of Risks, Costs, and Benefits