Reclaimed Water Use Regulations in the U.S.: Evaluating Changes and Regional Patterns in Patchwork State Policies from 2004–2023

Abstract

Water reuse, the beneficial use of highly treated municipal wastewater (reclaimed water), is expanding throughout the United States (U.S.); however, there are currently no federal reclaimed water use regulations, only guidelines. As a result, state policies on reclaimed water vary widely, emphasizing the need for a comprehensive understanding to facilitate coordinated national planning. Our systematic literature review, utilizing an online legal research database, presents an updated overview of U.S. reclaimed water policies from 2004 to 2023. A novel categorization scheme tracks policy changes, highlighting a 38% increase in states regulating reclaimed water between 2004 and 2023. We also created maps of current reclaimed water use regulations across the U.S. including: (1) a national overview of the reclaimed water policy landscape; and (2) documentation of non-food crop and food crop irrigation policies. As of November 2023, 74% of states (37/50) intentionally regulated reclaimed water use. Regions with historically low water scarcity, such as the Midwest, exhibited lower participation rates in reclaimed water regulation than water-scarce regions in the West. Of the 37 states regulating direct reclaimed water use in 2023, all allowed for at least some agricultural uses; 23 permitted non-food and food crop production use, while 14 states have statutory allowances for direct reclaimed water use on non-food crop production. As climate change stresses freshwater resources, our work provides up-to-date information for policymakers to navigate existing reclaimed water use policies.