Lab Matters Spring 2023 | Page 24


Water Reuse in the United States : A Growing Practice with Public Health Implications

By Hunter Adams , environmental laboratory supervisor , City of Wichita Falls and Sarah Wright , manager , Environmental Laboratories
Water reuse can take many forms , including direct potable reuse ( DPR , from wastewater straight to drinking water ); indirect potable reuse ( IPR , from wastewater to surface / groundwater to drinking water ) and non-potable reuse ( water reused directly from treated wastewater for agricultural and industrial purposes ). In contrast to the more traditional process of wastewater effluent being discharged into a waterbody and eventually being treated at a downstream site , IPR is usually more of a closed loop system and the water is reused by the same drinking water / wastewater jurisdiction .
In an effort to combat rising drought conditions and shrinking natural water supplies across the United States , the US Environmental Protection Agency ( US EPA ) developed a National Water Reuse Action Plan ( WRAP ) in 2020 . WRAP focuses innovation , funding and research on the nation ’ s water supply with the goal to improve water resilience , security and sustainability through collaboration . In October 2022 , a delegation of 42 water reuse experts traveled to Israel to examine their centralized water reuse systems .
A Desert Solution
Existential threats of water scarcity , rising sea levels and climate change have driven Israel ’ s water reuse policies . Since water is one of its most precious resources , every drop of water — even rooftop runoff — is regulated by the Ministry of Environmental Protection with all water rights belonging to the government . Because of this centralized approach , Israel produces nearly 80 % of the nation ’ s drinking water supply by desalination , and reuses 85 % of their treated wastewater effluent primarily for irrigation and some industrial uses .
The US has currently taken a very different regulatory approach to water reuse , with US EPA establishing guidance and a support framework through WRAP and states having primacy when it comes to establishing driking water and wastewater regulations equal to or more protective than SDWA and CWA . But as reuse practices progress , these decentralized state requirements will develop according to regional needs and create a patchwork of regulations . This means that while public health laboratories will not have a clear-cut template for reuse , they can prepare for potential monitoring needs to protect public health .
Planning and Looking Ahead
At a minimum , DPR will continue to follow the Safe Drinking Water Act ( SDWA ) regulatory framework . Designated state primacy agencies enforce SDWA compliance and may add any additional monitoring requirements that they see fit . IPR will follow the Clean Water Act ( CWA ) regulatory framework , because wastewater effluent intended for reuse enters an environmental buffer ( e . g ., receiving stream or reservoir ) before its final use . Once sourced for drinking water , that water will need to comply with SDWA regulations .
However , because reused water has not been acknowledged as a traditional potable water source in the US , there have not been long-term studies conducted on the composition of that water , specifically with contaminants of concern . It is not clear whether reused water , particularly DPR , will have higher or lower concentrations of unregulated contaminants such as perand polyfluoroalkyl substances ( PFAS ) and microplastics . A jurisdiction will need to determine if their wastewater and / or their environmental water sources in general have concerning levels of unregulated contaminants to decide whether water reuse can be equally protective of public health .
Monitoring needs could include routine unregulated contaminant testing in drinking water and wastewater . In wastewater , a jurisdiction may benefit from increased testing frequency of
22 LAB MATTERS Spring 2023
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