Waterborne Pathogens

Swimming Allowed

WERF researchers are diving into new efforts that will inform U.S. EPA’s upcoming revisions to recreational water criteria.

Preserving swimmable waters for our communities to enjoy is one of the cornerstones of the U.S. Environmental Protection Agency’s (U.S.EPA) Clean Water Act and a goal of the thousands of wastewater and stormwater treatment facilities throughout the country. It’s a responsibility that these facilities have upheld admirably, but one which relies on continued research to improve our understanding of waterborne pathogens and their sources, as well as development of improved tools and technologies to evaluate, and communicate, public health risks. Key to ensuring that our waters remain safe for the public’s use and enjoyment is U.S. EPA’s research plan to support the development of new or revised recreational water criteria by 2012.

WERF understands that these new criteria could have a significant impact on our subscribers and other municipalities across the country, so through our Pathogens and Human Health program, we have developed our own multi-year, multi-phase effort to inform U.S. EPA’s efforts and ensure that issues of importance to our subscribers are addressed.

Key areas of research include robust quantitative microbial risk assessment models, and relationships between standard culture and proposed genetic-based (qPCR) methods to quantify fecal indicators for water advisories. A particular effort is being made to fi ll in information gaps on inland waters, and tropical and subtropical egions. And by coordinating with U.S. EPA as it develops its research plan, we are ensuring that the resulting methods, data, and tools of our own research will inform criteria development and ultimately support utility management decisions. The table below lists four of WERF’s research efforts in this arena, either just beginning or planned to begin shortly.

Moreover, our research efforts will help make certain that there are strong correlations between the pathogen(s) and indicator(s) U.S. EPA chooses as the focus of its revised or new criteria. Our research will also help ensure that the methods U.S. EPA selects for monitoring (i.e., sampling, detecting, isolating, characterizing, and quantifying) such pathogens and indicators will make sense when employed in other Clean Water Act applications. In short, WERF wants to put the best possible science to bear on regulatory developments that stand to affect us all.

For WERF subscribers like the Northeast Ohio Regional Sewer District (NEORSD), the new criteria could have a very real impact on their efforts to address combined sewer overflows (CSO), as well as their bottom line. NEORSD is undertaking a multi-billion dollar CSO control program that must comply with the 1994 federal Combined Sewer Overflow Control Policy, which stipulates a post-construction water quality monitoring program in compliance with water quality standards and protection of designated uses. “Short of completely eliminating CSOs, full compliance with recreational use criteria for pathogens or pathogen indicators can be extremely difficult,” says Keith Linn, an environmental specialist with NEORSD. “We want EPA to have the best possible scientific information to get those criteria right.”

The pathogens issue

In this issue of Progress, we profile our first research effort designed to inform U.S. EPA’s new recreational water criteria: Quantification of Pathogens and Sources of Microbial Indicators for QMRA in Recreational Waters (PATH2R08). Work has just begun on filling in information gaps on waterborne pathogens and indicators from a range of different source waters. Researchers will then use this data to develop risk management tools to help resource managers prioritize source control and treatment programs.

One area in which U.S. EPA’s new criteria will have a major impact, is on stormwater control. WERF subscribers facing mandated improvements in CSO controls will find our profile of Characterizing the Quality of Effluent and Other Contributory Sources during Peak Wet Weather Events (03CTS12PP) of great interest. Researchers from San Francisco’s East Bay Municipal Utilities District are completing the final phase of research that will help utilities assess potential human-health risks associated with their blending efforts and compare the cost effectiveness of their in-plant wet weather flow management strategies with other options.

To learn more about our research efforts in these areas and our continuing work to inform U.S. EPA’s new recreational water criteria, visit us at www.werf.org/pathogens.

 Project Title Description
Quantification of Pathogens and Sources of Microbial Indicators for QMRA in Recreational Waters
WERF researchers will quantify the risks from waterborne pathogens from a variety of sources and use the data in Quantitative Microbial Risk Assessment models. The results will help managers make decisions on where to put their limited resources.
Determining the Relationship of Microbial Pollution and Associated Health Risks at Freshwater and Saltwater Beaches of FloridaThis cooperative research project will examine relationships between qPCR-based and culture-based test results, and identify appropriate pathogens and indicators in subtropical waters. Microbial source tracking using genetic markers and analysis of predictive modeling of health impacts will be included.
Concentration Dynamics of Fecal Indicators in Hawaiian Coastal and Inland Sand, Soil, and Water During Rainfall Events
WERF researchers will examine the fate and transport of fecal indicators in tropical sand and seawater during rainfall contamination events and look at how land-use patterns affect the abundance levels of these indicators in stream water and bank soil. The project will help us understand how indicators move in the watershed and will provide base data for management of risk. 
Measuring Water Ingestion During Water RecreationThis new WERF effort, which supports the Chicago Health, Environmental Exposure, and Recreation study, will measure water ingestion rates during primary and secondary contact recreational activities and allow to us to identify risks of ingestion.