Grantee Research Project Results

Final Report: Predicting and Equipping Private Well Owners at Risk of Microbial Contamination After Flooding Events

EPA Grant Number: SU840586
Title: Predicting and Equipping Private Well Owners at Risk of Microbial Contamination After Flooding Events
Investigators: Terry, Leigh , Jones, Nate , Kiaupa, Jourdan , Herr, Georgia , Webb, Alisha
Institution: The University of Alabama
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 1, 2023 through July 31, 2024
Project Amount: $24,899
RFA: 19th Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet Request for Applications (RFA) (2022) RFA Text |  Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources

Objective:

Nearly eight-hundred thousand Alabama residents depend on private wells for their water supply. Because of a lack of regulatory policies concerning the inspection of domestic wells and water quality maintenance, private well owners are maintaining and monitoring their water quality. However, a large proportion of Alabama residents are subject to failing healthcare and education institutions. The Black Belt of Alabama comprises of 17 counties that represent a culturally and historically diverse region, but is also represented by endemic poverty, high unemployment rates, and little-to-no access to higher education and health services. This project examined the impact of flood-induced contamination on private well water quality in the Alabama Black Belt. By employing a case-study approach to identify microbial contamination levels in shallow groundwater wells and combining results with geospatially modeled flood risk, this project aimed to educate and equip private well owners with user-friendly educational resources to reduce their exposure to microbial contamination. 

Microbial contamination levels were determined by processing field samples using two different testing procedures. Grab samples were collected from various wells near a wetland stream in Hale County, Alabama and tested with media provided by IDEXX Laboratories and Micrology Labs. Results from this testing were combined with flood risk modeling to develop the Flood Induced Contamination Risk Assessment Model, a GIS-based interactive model that can be accessed by private well owners to determine their likelihood of being at-risk following a flooding event. A myriad of available and reliable resources were also compiled in the Private Well Ownership Guide, a website that serves as a single-point source for information on groundwater, water testing, and remediation techniques.

Summary/Accomplishments (Outputs/Outcomes):

Each collection site saw a range of contamination levels throughout the testing period, with large spikes occurring after heavy rain events. Outside of the precipitation-related spikes, contamination levels hovered around a medium- to high risk of adverse health effects. Very rarely did contamination levels in the water samples comply with limits that are legally enforced on public water systems, deeming this water unfit for consumption. This contamination was determined to be caused by floodwater runoff and infiltration. The majority of publications on private well maintenance focus on risks posed by floodwater inundation, which occurs when open wells are submerged by floodwaters. The results from both the IDEXX Laboratories and Micrology Labs testing procedures show that groundwater infiltration from floodwater runoff and floodwater pooling around wellheads, pose the same risks as floodwater inundation. This determination was considered when developing the Flood Induced Contamination Risk Assessment Model, which dictated the threshold for locating wells within or near FEMA flood hazard boundaries. Using this model, 63% of Black Belt domestic wells were found to be located within a flood hazard area. On average, 61% of private wells were within flood hazards areas throughout the 17 Black Belt counties. Montgomery county saw the highest percentage of at-risk domestic wells, at nearly 85%.

Conclusions:

Private well owners in Alabama, totaling approximately eight-hundred thousand individuals, bear the sole responsibility for ensuring the quality of their water supply. The Environmental Protection Agency (EPA) does not have regulations in place for private wells. While state government programs provide guidance on well treatment and testing, the obligation lies on well-owners to monitor and maintain the health of their private systems. Although groundwater is generally low in contaminants, septic system failures due to soil conditions combined with flooding from frequent storms have created a groundwater quality epidemic in the Black Belt region of Alabama. Floodwater can infiltrate wells for extended periods, potentially exposing households to Escherichia coli (E. coli) and fecal coliforms. Here, the impact of flooding on well water users across the Black Belt was quantified. A case-study approach was employed to identify microbial contamination in shallow groundwater wells and geospatial modeling was used to characterize flooding risk across the Black Belt. The compilation of available and reliable resources into a single-point source will aid in educating and equipping well owners to reduce their exposure to microbial contaminants. By developing a comprehensive flood-induced contamination risk assessment model and providing accessible water quality testing resources, this research supports the protection of private wells and the well-being of communities in the Black Belt region of Alabama.

Phase II will consist of extended and more refined testing methods. The 2023 storm season, in which this research was conducted, was abnormally dry. The months of June through November in 2023 ranked in the driest third of a 129-year record, causing the sample wells dedicated to this project to run dry on a consistent basis. This research should be continued in future storm seasons to gain a more accurate view of contamination levels in private wells. In addition, sampling efforts should extend to neighboring counties, as well as extended to include wells that are not capped and would be prone to flooding inflow. Drawing samples from more diverse sources will allow Phase II of this project to begin development of a more well-rounded view of the entire Black Belt region.

Expanding laboratory procedures using a wider range of at-home test kits to compare with results from the advanced IDEXX Laboratory test procedure will ensure that Phase II provides the most up-to-date and well researched recommendations to private well users. Duplicate tests of each sample should also be an added measure to laboratory procedures, allowing for improved accuracy of test results. Additionally, to aid in improved accuracy of results, each separate laboratory procedure should be performed by the same team member during each week of testing. This will help reduce small variations in testing methods that lead to skewed results.

Phase II will act as an expansion on all aspects of the project, including outreach. During the next phase, appropriate permissions should be obtained to allow publication of the Flood Induced Contamination Risk Assessment Model, making it available for use by the public. Any applicable results and recommendations gained from the expanded sampling and testing procedures should be added to the existing Private Well Ownership Guide webpage. This webpage will also be updated and expanded with the most recent information available from the wide range of resources it references. To further this project's outreach efforts, Phase II will consist of partnering with SciREN, in which lesson plans for various age ranges will be created to teach the next generation the importance of water quality maintenance. 

Journal Articles:

No journal articles submitted with this report: View all 6 publications for this project

Supplemental Keywords:

Private wells, Alabama, black belt, water quality, well ownership

Relevant Websites:

AL Black Belt Private Well Ownership Guide Exit