Evaluation of Sanitary Sewers as a Source of Pathogen Contamination of Municipal Water Supply WellsEPA Grant Number: R834869
Title: Evaluation of Sanitary Sewers as a Source of Pathogen Contamination of Municipal Water Supply Wells
Investigators: Bradbury, Kenneth R. , Borchardt, Mark , Gotkowitz, Madeline B
Institution: University of Wisconsin - Madison , Marshfield Clinic Research Foundation , Wisconsin Geological and Natural History Survey
EPA Project Officer: Page, Angela
Project Period: June 1, 2011 through May 31, 2013 (Extended to December 31, 2013)
Project Amount: $598,580
RFA: Advancing Public Health Protection through Water Infrastructure Sustainability (2009) RFA Text | Recipients Lists
Research Category: Drinking Water , Water
Water supply wells and sewers are critical urban infrastructure. Pathogens in water produced by water supply wells threaten public health and infrastructure sustainability. Exfiltration from sanitary sewers is a known pathogen source. Our objectives are 1) to quantify the presence of pathogenic viruses in groundwater near urban sewer systems in hydrogeologic settings appropriate for loading groundwater: 2) to establish correlations between virus presence and sewer characteristics such as age, construction, materials, depth, and overall condition: 3) to evaluate the transport pathways of pathogenic viruses to deep supply wells: and 4) to use numerical modeling to develop estimates of the amount of sewer exfiltrant reaching groundwater and the probability of contamination of nearby water supply wells, and to extrapolate this information to other areas.
We will sample and analyze shallow groundwater at field sites adjacent to sewers in and around Madison, WI, using human enteric viruses as a key indicator of wastewater presence. Sites chosen will be hydrogeologically appropriate for contributing water to nearby deep municipal wells, and shallow monitoring wells will be installed at each site. We will analyze groundwater from shallow wells, municipal wells, and sewage for human enteric viruses. E. Coil, wastewater sterols, inorganic ions, and environmental isotopes. We will relate water - quality results to sewer characteristics such as location relative to the water table, age, materials, and construction. Extrapolations from study sites to the larger sewer system will involve both statistical approaches and numerical groundwater flow modeling.
The project will produce a significant set of data on groundwater quality adjacent to potentially-leaking sewers, along with correlations between virus presence, sewer characteristics, and local hydrogeology - all critical to infrastructure sustainability. Through predictive modeling we will assess the risk of viral contamination of drinking-water supply wells. Development of statistically and hydrogeologically rigorous data, including a checklist of infrastructure characteristics, on the potential loading of pathogens to groundwater from sewer exfiltration should be an important driver for the EPA and local utilities in proactively assessing risk and recommending monitoring, modification or repair of sewer and water supply infrastructure, all critical for sustainability.