Groups push for cleaner water at Conowingo Dam
BALTIMORE — The Waterkeepers Chesapeake and the Lower Susquehanna Riverkeeper Association filed an administrative appeal on June 8, urging the Maryland Department of the Environment to reconsider its recent water quality certification for the Conowingo Dam, which is owned and operated by Exelon Corporation.
Exelon has requested a new 50-year federal license to operate the dam, and to receive that license, the state must certify that the dam’s operations will not adversely impact water quality under the Clean Water Act.
“This is one of the most important decisions in the effort to clean up the Chesapeake Bay,” said Betsy Nicholas, executive director of Waterkeepers Chesapeake, a coalition of 19 independent waterkeeper organizations. “We shouldn’t be approving a 50-year license without a solid, accountable plan for
“This is one of the most important decisions in the effort to clean up the Chesapeake Bay. We shouldn’t be approving a 50-year license without a solid, accountable plan for removing sediment from behind the dam.” Betsy Nicholas, Waterkeepers Chesapeake executive director
removing sediment from behind the dam.”
The Conowingo Dam was completed in 1928, and since that time, it has been trapping sediment and nutrient pollution from the Susquehanna River and its 27,000-square-mile drainage area. Sediment is one of the three key pollutants, along with nitrogen and phosphorus, that is regulated under the federal Chesapeake Bay cleanup plan, known as the TMDL.
Scientists have concluded the reservoir behind the dam is at capacity and cannot trap any more sediment. After large storms, powerful floodwaters can scoop out, or “scour,” the stored sediment behind the dam and send that downstream to the Chesapeake Bay in the form of pollution.
“Sediment runoff from agriculture and development has been stockpiling behind Conowingo dam for nearly 100 years,” said Ted Evgeniadis, Lower Susquehanna Riverkeeper. “The Susquehanna River is a public resource, and Exelon profits from operating a dam on it. Exelon therefore shares a responsibility to help prevent this sediment from polluting the Bay, and we believe the State of Maryland must hold them accountable to do so.”
Waterkeepers Chesapeake, Lower Susquehanna Riverkeeper Association and Earthjustice submitted public comments during the relicensing process. The organizations say the Maryland Department of the Environment has failed to address them.
The organizations also say that, for the certification to protect water quality, the state must understand the full potential of large flooding events that could cause dramatic harm to the Bay. The new license covers 50 years, but the state has yet to conduct a study or model how much sediment pollution would be scoured from behind the dam during a 50-year storm, or even a 25year storm, which has an 83 percent chance of occurring during the license period. Scientists say large storms and heavy rain events are happening more frequently due to climate change, which means the risk of a catastrophic storm continues to increase.
“In just the last month, we’ve seen serious, damaging flooding throughout the region,” Nicholas said. “It’s irresponsible not to account for the increasingly likelihood that Conowingo Dam experiences a major flood during the next 50 years.”
The Maryland Department of the Environment issued its water quality certification for the Conowingo Dam on May 11. While the certification acknowledged the impact of the dam on water quality, including the threat posed by the accumulated sediment, it does not put specific measures in place to address the sediment.
“When Congress adopted the Clean Water Act, it purposefully gave states a very broad authority on federal permits,” said Jennifer Chavez, attorney for Earthjustice, which is serving as legal counsel for the appeal. “We’ve filed this request for reconsideration because we want to ensure that Mar yland uses the best available science before exercising that critical authority.”
The Maryland Department of the Environment will review the appeal and either grant the request to reconsider and revise the certification or deny it. There is no deadline by which the department must make its decision.