The Conowingo Factor

Since its inception in 2012, the Clean Chesapeake Coalition has fought to bring attention to the largest single point source of pollution to Bay waters: the reservoir behind the Conowingo Dam in the lower Susquehanna River. Exelon, current owner of the Dam, is in the process of seeking a new, 46-year license from the Federal Energy Regulatory Commission (FERC) and, as part of that process, section 401 of the federal Clean Water Act requires that the state of Maryland issues a Water Quality Certification (WQC) for the Dam. On April 27th of this year, the Maryland Department of the Environment (MDE) did indeed issue the WQC, with special conditions - conditions that Exelon is now suing Maryland over in two courts and administratively. Exelon maintains that the Dam is not a source of pollution and that the conditions imposed by the State are impracticable. On July 26, 2018 rain events (not hurricanes or tropical storms) caused Exelon to open 20+ spill gates resulting in a river flow in excess of 400,000 cubic feet per second (cfs). At least two million tons of sediment was scoured from behind the Dam into the Bay, bringing with it an estimated 42,000 tons of nitrogen and 3,400 tons of phosphorus. To put this in perspective, the EPA's ANNUAL nitrogen target for 2025 the ENTIRE STATE of Maryland is 23,000 tons, or approximately half of what came through those gates over the course of a couple of days in July of this year. During the recent midpoint assessment of the Bay Total Maximum Daily Load (TMDL), aka pollution diet, the EPA made a bold decision – they created an additional WIP specific to the Conowingo Dam. This calls for the watershed states, the District of Columbia and Exelon to formulate a plan to deal with this imminent threat. Yet Exelon has repeatedly stated that their renewable energy plant should not be held responsible and pointed to the upstream states as the culpable parties. While there is no doubt that we all have a ways to go to meet TMDL goals, the Dam represents a ticking time bomb for past, current and future efforts that cannot be denied, downplayed or ignored.