R/WQ-5

Impact/Outcome:

Assessing the Anacostia River Tunnel's Impact and Enlisting Citizen Science

Summary: Maryland Sea Grant-supported researchers studied changes in the Anacostia River's phytoplankton and bacteria to assess the effectiveness of a new wastewater remediation system, while also mobilizing and training citizen scientists to monitor their river and garnering interest from District of Columbia decision-makers.

Relevance: The Anacostia River, which flows through the nation's capital, is one of the Chesapeake Bay's most polluted tributaries. It has long been unhealthy for humans and aquatic organisms. Millions of gallons of urban sewage and stormwater runoff routinely flow into the river. Designed to reduce the combined sewer outflow by up to 80 percent, the 2.3-mile-long Anacostia River Tunnel began operating in March 2018. Studying changes in phytoplankton, bacteria, and the river's microbial community will help assess the tunnel's effectiveness in reducing algal blooms and bacterial contamination. Additionally, engaging citizen scientists to help continuously monitor the river will be critical to its ongoing restoration.

Response: Through a Sea Grant-supported project, two researchers, a Sea Grant fellow, and several undergraduate students from Gallaudet University synthesized four years of data on nutrients and phytoplankton collected biweekly and monthly before the tunnel's construction. They also conducted sampling after the tunnel began operating in spring 2018. Unrelenting rains made 2018 the wettest fall on record in Washington, D.C., leading to higher-than-normal stormwater runoff and nutrient loading from land and complicating efforts to accurately assess the tunnel's effectiveness. In 2019, 15 sampling trips were conducted, and two experiments were led by the MDSG fellow. The experiments manipulated water with various nutrient additions to understand which phytoplankton communities would develop under different nutrient regimes, helping to improve interpretation of the field data. 

Results: Working with the Anacostia Riverkeeper, the Sea Grant-supported project helped train 121 volunteers to sample for E. coli bacteria at multiple locations. Data from this new citizen-science effort is used weekly to update the SwimGuide, through which residents can evaluate the river's safety for swimming and other activities. At the 2019 Anacostia River Festival, more than 7,000 attendees interacted with the Sea Grant fellow and undergraduate students who presented a popular working model of a wastewater treatment plan to illustrate the tunnel's purpose. The researchers also shared the synthesis of the pre-tunnel monitoring data with the District of Columbia Department of Energy & Environment, which prompted it to encourage Gallaudet-a university for the education of the deaf and hard of hearing-to seek additional collaborative research opportunities and engagement with District officials.