Early Career Award: Framework for Quantifying Microbial Risk and Sustainability of Potable Reuse Systems in the United States

EPA Grant Number: R835823
Title: Early Career Award: Framework for Quantifying Microbial Risk and Sustainability of Potable Reuse Systems in the United States
Investigators: Gerrity, Daniel
Institution: University of Nevada - Las Vegas
EPA Project Officer: Packard, Benjamin H
Project Period: August 1, 2015 through July 31, 2018
Project Amount: $329,650
RFA: Human and Ecological Health Impacts Associated with Water Reuse and Conservation Practices (2014) RFA Text |  Recipients Lists
Research Category: Water , Health


This research addresses three critical issues related to the spectrum of potable reuse applications in the United States: (1) quantifying the microbial and chemical risks associated with various treatment trains in de facto, ‘planned’ indirect (IPR), and direct potable reuse (DPR) paradigms; (2) developing a framework for comparing the sustainability of IPR versus DPR; and (3) evaluating alternative treatment trains based on the formation and mitigation of conventional and emerging disinfection byproducts (DBPs) and other contaminants of emerging concern (CECs). The research is intended to demonstrate that ‘planned’ potable reuse offers a safe and sustainable alternative to conventional drinking water practices, although the regulatory framework may need to be augmented to ensure that all potable reuse treatment trains are adequately protective of public and ecological health.


Public health will be evaluated based on static and dynamic risks associated with pathogens and CECs at concentrations typically observed across the potable reuse spectrum. The quantitative microbial risk assessment (QMRA) will include a disease transmission model (i.e., S-E-I-R) to account for temporal variability in pathogen loading to wastewater systems, which will provide a feedback mechanism to characterize outbreak conditions. A system dynamics model will be used to evaluate the sustainability of IPR versus DPR in Southern Nevada on the basis of sociopolitical, economic, and environmental factors. Operational conditions specific to ozone and biological activated carbon (BAC) will be optimized at pilot-scale with respect to the formation and mitigation of trihalomethanes (THMs), haloacetic acids (HAAs), nitrosamines, and a suite of CECs (e.g., perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)).

Expected Results:

The research will generate models and frameworks that can be used to quantify the impacts of potable reuse paradigms or treatment trains on public and ecological health. The results will be broadly disseminated to promote widespread implementation of potable reuse, which will increase resource security by expanding water portfolios throughout the United States in a sustainable manner.

Publications and Presentations:

Publications have been submitted on this project: View all 23 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 3 journal articles for this project

Supplemental Keywords:

drinking water, decision making, engineering,

Progress and Final Reports:

  • 2016 Progress Report
  • 2017 Progress Report
  • Final Report