Earlham scientists collaborate with city to assess risks of local dam removal

Breaching Richmond’s Weir Dam should not release significant contamination into the Whitewater River, according to a new study by researchers at Earlham College.

A team from Earlham’s Earth and Environmental Science Department collaborated with the City of Richmond Sanitary District on a pre-dam removal study to determine if there are potentially harmful levels of contamination present in the sediment trapped behind the Weir Dam. The City of Richmond recently received grants from the Indiana Department of Natural Resources and U.S. Fish and Wildlife Service to remove the dam. 

Using high-tech satellite navigation equipment, Earlham students and faculty surveyed the river channel up and downstream of the century-old dam. The team also collected sediment cores to characterize the amount and nature of the material accumulated behind the dam.  Sediment samples analyzed by an independent lab contained trace amounts of metals and hydrocarbons, but no pesticides or PCBs were detected.

“The sediment accumulated behind the dam is a record of the industrial history of the Whitewater Gorge,” said Andy Moore, a professor of earth and environmental science at Earlham. “While we cannot guarantee there isn’t any contamination, the concentrations measured were much lower than any of us anticipated.”

Moore and Shannon Hayes, an Indiana licensed professional geologist and geology curator at Earlham, began the project last summer with students Garris Radloff, Amelia Richardson and Katherine Liu. Their work was part of Earlham’s Summer Collaborative Research program and funded by an anonymous donor, the Earlham College Stephen and Sylvia Tregidga Burges Endowed Research Fund and the Borman Family Foundation.

“This is an excellent opportunity for Earlham students to gain experience working on real-world problems while providing a valuable service to the city,” Hayes said.

“Our goals were to assess the levels of contamination stored behind the dam and provide baseline data to assess changes in the river after the dam is breached,” she said. “Our research will continue after the dam is removed as we track sediment migration and monitor the river’s recovery.”

The Weir Dam was built to divert cooling water to a city-owned manufactured natural gas plant which no longer exists. City officials say removing the dam will open the river to fish passage, improve safety, and provide opportunities to redevelop the area for recreation. They plan to remove the dam in late summer 2022. 

“Andy and Shannon have a lot of real-world experience connected to every single aspect of the work that we did,” said Katherine Liu, a junior geology major from Madison, Wisconsin, who is participating in her first student-faculty research project on campus. “Now I’m considering this kind of work as a career.

“The dam is now over 100 years old,” Liu said. “I really hope to witness the removal of the dam before graduation.”

This is Richardson’s second opportunity to use high-tech surveying equipment available in Earlham’s inventory. The senior geology major from the San Francisco Bay Area was a participant in a pilot program on campus that was sponsored by the National Science Foundation. The project resulted in the creation of high-resolution topography maps of Miller Farm, Earlham’s experiential agricultural program.

“Using these tools in a real-life research setting — we’re creating a profile of the river bed — has been really valuable,” she said.

Members of the research team expect to complete their research this fall and present their findings at the Geological Society of America’s upcoming conference in Cincinnati, Ohio, in April.

“My academic interests are in water quality so I’m eager to share our findings at a professional conference,” Radloff said, a chemistry and geology double-major from the Peoria, Illinois, area.

“Most of the work I intend to apply for in the future is related to hydrology,” he said. “This is great for my resume and the opportunity to achieve that goal.”