A large report by the National Academies of Sciences, Engineering and Medicine says gray water and stormwater are great new sources for water supplies, but we don’t know enough about the risks of reusing the water for landscape irrigation, toilet flushing and groundwater recharge.
One of the greatest hurdles is the absence of risk-based guidelines that ensure water quality is protective of public health, the report says. Rigorous, risk-based guidelines could improve safety, reduce spending on unnecessary treatment, and assist communities that lack an existing regulatory framework for on-site water supplies.
The authors make three recomendations:
- Develop rigorous, risk-based guidelines at the national level (EPA) in consultation with the states
- Study the behavioral responses of homeowners who reuse greywater to see long-term water use trends
- Regulations need to take into consideration new technologies for grey water and stormwater treatment.
The report was sponsored by by the U.S. Environmental Protection Agency; National Science Foundation; Water Research Foundation; Water Environment Research Foundation; Los Angeles Department of Water and Power; WateReuse; City of Madison, Wisconsin; National Water Research Institutes; and through the Academies’ Presidents’ Fund