Water Resources Research Act Program

Details for Project ID 2017PA231B

Evaluating Septic Systems as a Source of Enteric Pathogens in Private Water Supply Wells of Pennsylvania

Institute: Pennsylvania
Year Established: 2017 Start Date: 2017-03-01 End Date: 2018-02-28
Total Federal Funds: $22,000 Total Non-Federal Funds: $47,645

Principal Investigators: Heather Murphy

Abstract: Pennsylvania (PA) has the second highest number of private water supply wells in the US, with approximately 3 million people relying on well water (Fleeger, 1999). Private wells are not regulated by the U.S. Environmental Protection Agency or any other authority, and thus the burden is on the homeowner to test and treat their water accordingly. Between 1971 and 2008, 30% of all waterborne outbreaks in the US were associated with the consumption of untreated groundwater. PA had the second highest number of outbreaks during this time period. The CDC recently identified that the burden of disease associated with private wells in the US is unknown and could be significant. Based on previous research (Murphy et al., 2015), I estimate that there could be 81,000 cases of acute gastrointestinal illnesses (AGI) per year in PA due to private well water. The social and economic burden of waterborne AGI can account for numerous lost work/ school days, higher health care costs and the potential development of longer-term health complications. In order to better understand the health risks associated with the consumption of private well water, it is crucial to understand the occurrence of microbial pathogens in groundwater as well as the factors that contribute to pathogen presence in groundwater supplies such as geology, location and design of septic systems, well construction, and rainfall events. Collection of microbial water quality information is necessary in order to design more targeted public health studies, and to inform risk assessment models so that appropriate recommendations for public health interventions can be conceived. In this project, I will investigate whether septic systems are the source of enteric pathogens found in private wells and how rainfall events may contribute to their occurrence in groundwater supplies. The approach will include observation of the temporal variability of pathogen presence in groundwater supplies in PA. There are two key hypotheses of this research: 1) Septic systems are contaminating groundwater supplies with enteric pathogens, specifically enteric viruses in fractured rock aquifers in rural PA; and 2) A temporal shift exists between the detection of microbial indicator organisms and enteric pathogens following rainfall events in groundwater wells in fractured rock aquifers because of different transport mechanisms in the subsurface environment. These hypotheses will be tested by investigating the mechanisms contributing to the leaching of septic systems and resulting microbial contamination of private groundwater wells. This research will help State and Federal regulators establish guidelines to support households in the protection or treatment of their private well to ultimately protect public health.