Appeal says certification fails to recognize potential harm to the Chesapeake Bay from sediment stored behind the dam
(Baltimore, Md.) – Waterkeepers Chesapeake and the Lower Susquehanna Riverkeeper Association filed an administrative appeal on June 8, 2018, 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, in order to receive that license, the State of Maryland 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 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 that the reservoir behind the dam is now 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 that 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 25-year 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,” said Nicholas. “It’s irresponsible not to account for the increasingly likelihood that Conowingo Dam experiences a major flood during the next fifty years.”
The Maryland Department of the Environment issued its water quality certification for the Conowingo Dam on May 11, 2018. 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 Maryland 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.
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Waterkeepers Chesapeake is a coalition of nineteen independent programs working to make the waters of the Chesapeake and Coastal Bays swimmable and fishable. www.waterkeeperschesapeake.org
The Lower Susquehanna Riverkeeper Association is a non-profit watershed association that seeks safe drinking water, sustainable use of natural resources, and the ability to fish and swim in the Susquehanna River and her tributaries. www.lowersusquehannariverkeeper.org
As the nation’s original and largest nonprofit environmental law organization, Earthjustice leverages our expertise and commitment to fight for justice and advance the promise of a healthy world for all. www.earthjustice.org
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