Located near the mouth of the Susquehanna River, Conowingo Hydroelectric Generating Station, also known as Conowingo Dam, is a hydroelectric power plant owned by Exelon Corporation (Leaving MDE). The dam was originally constructed in 1928 and has been in operation ever since. Special attention has recently been drawn to the Conowingo due to it losing its ability to trap nutrient and sediment pollution, and the application by Exelon Corporation to renew their Hydropower license to operate the dam.
The Susquehanna River provides almost 50% of the freshwater entering the Chesapeake Bay. The river carries about 40% of the nitrogen, and 25% of the phosphorus and sediment that enter the Bay. Conowingo, like other dams, has a large reservoir behind the dam that traps some of the nutrient and sediment pollution. However, over time the sediments, nitrogen, and phosphorus have gradually accumulated behind the dam, filling the reservoir and causing the Conowingo to stop trapping nutrient and sediment pollution.
To protect water quality and safeguard the river from environmental harm, operators of hydroelectric dams periodically required to obtain a Hydropower license to continue operation. Hydropower licenses are reissued by the Federal Energy Regulatory Commission (FERC) every 30-50 years. Applicants for license renewal must first obtain a water quality certification from the state in which the project is located. Conditions specified in a State water quality certification become conditions in the federal license.
Exelon Corporation applied for water quality certification of the project on May 16, 2017. Maryland Department of the Environment has one year from the application date to make a final decision.
Learn more about the Conowingo and its environmental impacts (Leaving MDE).
Please direct questions or comments to Dinorah Dalmasy
1800 Washington Boulevard, Baltimore, MD 21230