Microbial Treatment\nTargets for Potable and Nonpotable\nWater Reuse – A Comprehensive Update and Harmonization

Increasing\npressures on traditional sources of water\nhave accelerated\nthe adoption of water reuse throughout the world. A key consideration\nfor communities pursuing water reuse is understanding the amount of\ntreatment that is needed to ensure adequate human health protection.\nSeveral U.S. EPA documents describe the importance of managing acute\nmicrobial risks and highlight the utility of quantitative microbial\nrisk assessment for developing “fit-for-purpose” treatment\ntargets based on the source of water and end-use. However, there are\nno U.S. federal water reuse regulations and states are currently considering\nmicrobial treatment targets for various applications. Previous publications\nhave yet to address this need by using an updated and consistent set\nof input parameters to present risk-based microbial treatment targets\nacross a wide range of sources of water, end-use applications, and\nhealth benchmarks. This work combines the most current modeling inputs\nand dose–response parameter values to provide probability of\ninfection and disease burden-based microbial treatment targets for\nuntreated municipal wastewater, untreated onsite wastewater, graywater,\nstormwater, and roof runoff water used for potable reuse, indoor nonpotable\nuse, and landscape irrigation applications.