Research To Standardize Pathogen Monitoring For Water Reuse

Study funded by The Water Research Foundation will create a protocol for evaluating pathogens in treated wastewater effluent

Walnut Creek, CA - A new study from The Water Research Foundation (WRF) is underway to help utilities and regulators evaluate pathogen concentrations in treated wastewater effluent for potable reuse applications. Led by Carollo Engineers, with the Southern Nevada Water Authority, San Diego State University, CDM Smith, and Trussell Technologies as co-investigators, WRF project 5309, Developing a Protocol for Evaluating Pathogen Concentrations in Secondary Effluent, will run over 24 months to close a gap in how the industry assesses treated effluent.

The research team also includes 21 utilities across the United States and Australia, along with regulatory agencies from Arizona, California, Colorado, Nevada, and Utah.

As interest in potable reuse grows, utilities and regulators lack a standardized method for determining pathogen concentrations in treated effluent. Extensive research has been conducted on pathogen monitoring in raw wastewater, but no broadly accepted protocol exists for characterizing pathogens in secondary and tertiary effluent. That gap creates uncertainty for utilities pursuing potable reuse projects and for regulators evaluating pathogen reduction requirements.

To close that gap, the research team will review existing regulations, monitoring programs, and pathogen characterization studies from across the water sector. Researchers will evaluate sampling approaches, analytical methods, and treatment performance data, then combine those findings with utility datasets, stakeholder interviews, and field verification to develop guidance that applies across a variety of reuse projects and regulatory requirements.

Applying Machine Learning to Pathogen Data

A key element of the study is the evaluation of pathogen monitoring data from utilities representing a wide range of treatment technologies and geographic regions. The team will also apply advanced statistical analyses and machine learning techniques to better understand what drives pathogen occurrence and treatment performance in secondary and tertiary treatment systems.

Amos Branch, Ph.D., water reuse technologist at Carollo Engineers and principal investigator for the project, believes clear, consistent pathogen data is essential to advancing potable reuse with confidence:

"Potable reuse projects depend on a clear understanding of pathogen occurrence and treatment performance, but approaches for characterizing pathogens in treated effluent vary significantly," said Branch. "Our goal is to give utilities and regulators a consistent, scientifically robust framework they can rely on. By bringing together data, experience, and perspectives from across the industry, we can replace that inconsistency with a standard the whole sector can build on."

Upon completion, the research team will produce a guidance document and protocol for evaluating pathogen concentrations in secondary and tertiary effluent, along with recommendations for data quality, study design, and future research needs. Findings will also be shared through technical publications, industry presentations, and WRF communication channels.

About Carollo Engineers

For over 90 years, Carollo Engineers has provided a full range of innovative planning, design, and construction management services to address the water needs of municipalities, public agencies, private developers, and industrial clients. Carollo develops robust water management strategies that leverage collaboration, provide multi-benefit solutions, and achieve sustainability and resilience. Carollo has 1,900 employees located in more than 60 offices across North America. To learn more about how Carollo is “Working Wonders With Water®” call (800) 523-5826 or visit www.carollo.com

About The Water Research Foundation

The Water Research Foundation (WRF) is the leading research organization advancing the science of all water to meet the evolving needs of its subscribers and the water sector. WRF is a nonprofit, educational organization that funds, manages, and publishes research on the technology, operation, and management of drinking water, wastewater, reuse, and stormwater systems—all in pursuit of ensuring water quality and improving water services to the public. For more information, visit www.waterrf.org