Department of Biosystems & Agricultural Engineering Risk Modeling

EPA awarded $8,492,000 to four institutions for research to improve our understanding of the occurrence and concentration of opportunistic pathogens (OPs) and disinfection by-products (DBPs) in drinking water distribution systems.

OPs, such as Legionella, mycobacteria, and Pseudomonas, can grow in drinking water systems and pose potential risks to public health. The occurrence of these and other microbial pathogens are also associated with contaminated storage facilities and other problems in water distribution such as backflow, cross-connections, and low and negative pressure incidents. If left untreated, these contamination events can increase public health risks from gastrointestinal and other waterborne illnesses. Unfortunately, the disinfectants used to control these pathogens can cause additional problems by reacting with natural organic matter, bromide, and other contaminants to form DBPs, which also have the potential to be harmful to human health.

The goal of this research is to identify environmental conditions and niches favorable to colonization, microbial growth, and propagation of these contaminants in drinking water distribution systems. Research results from this RFA should improve our understanding of how to control these contaminants and help inform water infrastructure management and risk mitigation practices to ensure clean and safe drinking water.

The following institutions are receiving an award:

Georgia Tech Research Corporation, Atlanta, Georgia

Project Title: Integrated Water Microbiome and Disinfection Byproducts Monitoring and Management to Advance Drinking Water Quality

Principal Investigator: A.J. Pinto

Award Amount: $2,123,000

Project Summary: The overall goals of this project are to develop an integrated framework to quantitatively monitor the drinking water microbiome, including waterborne pathogens (WPs) and DBPs, and holistically manage WP and DBP risks in drinking water storage and distribution systems (DWSDSs) using inclusive and actionable risk metrics. This goal of an integrated framework will be realized through two research objectives: (1) enacting a comprehensive spatial-temporal monitoring and characterization of water chemistry and microbiology of multiple full scale DWSDSs in different regions of the country; and (2) formulating an integrated and actionable risk assessment and management framework to mitigate WP and DBP risks and identify the underlying trade-offs to optimize drinking water quality in DWSDSs. This project will generate a unique dataset that concurrently quantifies WPs and regulated and unregulated DBPs in a diverse range of DWSDSs and puts this data in rich context with a thorough characterization of water chemistry and microbiology.

View the research abstract from the Georgia Institute of Technology.

Michigan State University, East Lansing, Michigan

Project Title: Winning the Race Against Competing Risks: Optimizing Drinking Water Disinfection to Minimize Opportunistic Pathogen & DBP Risks

Principal Investigator: Jade Mitchell

Award Amount: $2,123,000

Project Summary: The goal of this project is to better understand and predict occurrence of DBPs, OPs and the associated health risk tradeoffs posed by them in drinking water distribution systems (DWDS) across the continental U.S. The objectives of this project are to: (1) Develop a strategic sampling program based on health data and DWDS characteristics; (2) Assess the occurrence and co-occurrence of DBPs and OPs and evaluate contributing factors in nationally representative DWDS through field sampling; (3) Characterize risks and system risk factors associated with DBP and OP occurrence and concentrations and their risk tradeoffs for multiple communities and populations; and (4) Engage and collaborate with stakeholders and partners to support risk management within the water quality community of practice. The outcome of this work will enable movement away from routine monitoring for these hazards towards tools for more comprehensive water system evaluation, and risk-based and prioritized monitoring strategies based on DWDS characteristics, biological, chemical, and physical parameters.

View the research abstract from Michigan State University.

University of Minnesota, Minneapolis, Minnesota

Project Title: Innovations in Sampling, (Bio)Analytical Chemistry, and Analytics to Characterize Disinfectant Use Tradeoffs in U.S. Water Systems for Minimizing Exposure to Opportunistic Pathogens and DBPs

Principal Investigator: Raymond M. Hozalski

Award Amount: $2,122,997

Project Summary: This application proposes a highly innovative project to assess the tradeoffs between OPs and DBPs and develop strategies for limiting exposure to both classes of water contaminants via U.S. drinking water distribution systems. Water utilities selected for this project represent a range of water qualities, treatment operations, and geographic distribution across the U.S. The proposed project will generate novel data on OP and DBP occurrence in U.S. water distribution systems, including small systems in rural Alaska that typically are understudied and serve economically disadvantaged Alaska native populations.

View research abstract from the University of Minnesota.

University of Texas, Austin, Texas

Project Title: Consortium on Disinfection By-products and Opportunistic Pathogens in Water Networks (CO-DOWN)

Principal Investigator: Mary Jo Kirisits

Award Amount: $2,123,000

Project Summary: This proposal’s aim is to achieve a nationwide study of the prevalence of OPs, their free-living amoebae vectors, and (un)regulated DBPs across a wide variety of sizes and types of DWDS; further, researchers will examine fundamental scientific hypotheses related to the occurrence of OPs and DBPs in DWDS and their relative risks. Utility partners will assist with performing one sampling event per year from 5- 10 locations in their DWDSs. Results will help identify patterns of OPs and DBPs, as well as how hazard prevalence is correlated with general water quality and DWDS factors.

View the research abstract from the University of Texas at Austin.

Originally Published on the EPA website