COLLEGE PARK, Md. – Following one of the largest sewage spills in U.S. history, University of Maryland researchers have detected high levels of fecal-related bacteria and disease-causing pathogens in the Potomac River, raising urgent public health concerns and underscoring the risks posed by aging sewer infrastructure.
Water sample results collected at the site by researchers show high levels of E. coli are present along with Staphylococcus aureus (the bacteria that causes Staph infections). An antibiotic-resistant strain of S. aureus, MRSA, was also identified at the site of the sewage overflow.
"People coming into contact with the impacted water or land are at risk of becoming infected with these bacteria, which can lead to serious health conditions," said Dr. Rachel Rosenberg Goldstein , microbiologist and assistant professor at UMD's Department of Global, Environmental, and Occupational Health. "Although most people are not swimming in the frozen river in February, bacteria can survive in freezing temperatures and become active again when temperatures rise."
Results include:
E. coli bacteria – on Jan. 21 water samples from where sewage entered the Potomac were over 10,000 times above EPA recreational water quality standards. On Jan. 28 samples at the site were lower, but still over 2,500 times above water quality standards. At a site over 10 miles downstream from the sewage overflow on Jan. 28, E. coli were 1.5 times above the standard.
Staphylococcus aureus – on Jan. 21 and 28, the pathogen was detected at the site where sewage entered the Potomac and at a site nine miles away. Of the sites sampled, 33% were positive for S. aureus, higher than found in other surface waters containing this bacteria. An antibiotic-resistant strain of S. aureus, MRSA, was also identified at the site of the sewage overflow.
Out of an abundance of caution, people near the spill site in Maryland, Washington, D.C. and downstream should avoid contact with impacted river water and land until E. coli levels meet water quality standards again, says Goldstein. For people who come into contact with impacted water or soil, she recommends washing skin with soap and water or an alcohol-based sanitizer and laundering clothes with detergent at the warmest temperature and machine dry.
The team's testing began after hundreds of millions of gallons of sewage gushed from a broken pipe into the Potomac River on Jan. 19. Goldstein's Water Quality, Outreach and Wellness Lab (WOW) went directly to the source and other sites downriver to test the water for fecal-related bacteria and pathogens shortly afterward. The team returned one week later, working with members of the Potomac Riverkeeper Network (PRKN), to take more samples. The results analyzed by the WOW Lab point to major public health concerns and highlight the risks of crumbling sewer infrastructure.
Up to 75,000 sewage overflows happen every year in the United States, according to UMD's Water Emergency Team (WET), exposing residents to raw sewage, waterborne pathogens and possibly antibiotic-resistant bacteria. The effects are serious, including illnesses such as bacterial infections that can cause serious illness and death. The overflows can also raise feelings of anxiety.
Goldstein and Dr. Marccus D. Hendricks , associate professor of Urban Studies and (Environmental) Planning at UMD, co-lead the WET project, a UMD Grand Challenges awardee and joint venture between the WOW Lab and the Stormwater Infrastructure Resilience and Justice (SIRJ) Lab. WET was developed as a community-driven rapid-response to sewer overflows and backups in underserved African American communities in Baltimore and the surrounding region.
WET's earlier research showed that marginalized urban communities are often most vulnerable to sewage overflows, and along with the physical effects, these overflows can contribute to stigma and feelings of disenfranchisement in the communities.
Studies by Hendricks' SIRJ Lab in Washington, D.C. shows that above-ground development in the city has outpaced stormwater and sewer infrastructure development, likely straining the capacity of already outdated systems.
"Investment, maintenance and rehabilitation of drainage and other water resources infrastructure have been slow and the effects of this are clear in this Potomac sewage spill," Hendricks said. "National reporting has consistently shown over time that water resources infrastructure, such as stormwater and sewer systems, are underfunded compared to other essential systems like transportation. And then you have incidents like this."
Despite bipartisan efforts to invest and update infrastructure, such as the 2021 Bipartisan Infrastructure Law and provisions in the 2022 Inflation Reduction Act, Hendricks says it is likely that incidents similar to the Potomac spill will continue to happen at various scales due to underfunding and the enormity of the job.
"This issue isn't going away – solving the recent Potomac spill is not a simple one-time fix. We need significant and ongoing investment in system upgrades and maintenance," said Hendricks.
The WOW Lab team and PRKN, a non-profit working to protect the right to clean water in the Potomac and Shenandoah watersheds, worked together to increase the number and sites of water samples tested. They continue to take water and soil samples in the area. The WET project regularly works directly with community organizations and neighborhood associations, with a commitment to sharing lab research findings with affected communities and local policymakers.
The WET project, led by the UMD School of Public Health and School of Architecture, Planning, & Preservation, is one of 16 UMD Grand Challenges Team Grants that provide three years of funding to research teams seeking solutions to the grand challenges of our time.
