Citing nutrient pollution, environmental groups appeal new 50-year license for Conowingo Dam

Environmental groups have appealed a ruling by a federal commission that last month granted Maryland’s Conowingo Dam a new 50-year license.

The groups are concerned that the license missed an opportunity to address several environmental problems caused by the hydroelectric dam, but they also contend that the Federal Energy Regulatory Commission ran afoul of certain legal duties in issuing it.


At one time, the dam, which spans the Susquehanna River, a Chesapeake Bay tributary that flows between Harford and Cecil counties, trapped a significant amount of sediment and pollutants that would have flowed downstream. But now it’s full, and when big storms come, the trapped debris and nutrients rush down the river and into the bay, burying underwater vegetation and contributing to damaging algae blooms.

The unnatural flow of water through the dam also affects aquatic life. Drastic fluctuations in the river’s depth below the dam sometimes strands fish in shallow pools with insufficient water, leaving them vulnerable to predators. And the dam itself blocks migrating fish from heading upstream. On average, its two fish lifts transport a couple thousand shad and herrings each year, when environmental regulators say there should be millions.


As part of its new license, some environmentalists in the state want Exelon, the power company that operates the dam, to do more to mitigate the damage, or pay a larger sum for the harm it’s causing as it profits off the river. They argue that the federal commission failed in its duty under the Clean Water Act to consider environmental impacts closely enough when it decided to grant the license.

Storm debris gathered at the northwest corner of the Conowingo Dam. A new 50-year license for the dam got key federal approval in late March, but environmental groups say the agreement is a missed opportunity to compel Exelon, which runs the dam, to do more to stop pollutants flowing down the Susquehanna River and into the Chesapeake Bay.

“The license issued is for 50 years. And there is nothing in that license that’s going to address the nutrient sediment reductions needed,” said Betsy Nicholas, executive director of Waterkeepers Chesapeake, one of the groups challenging the Conowingo license.

Nutrient sediment reductions are required under the Chesapeake Clean Water Blueprint, a plan set in 2010 to reduce a certain amount of pollution in the bay from bordering states by 2025.

In their appeal, the organizations are calling on FERC to hold another hearing to reconsider Exelon’s license for the dam.

A spokesperson for the federal commission declined to comment on the appeal, but said it has 30 days to act on the filing.

Some of the environmentalists’ concerns about Conowingo stem from a settlement agreement that Maryland reached with Exelon in 2019. In that settlement, Maryland agreed to waive its right to issue a water quality certification for the dam in exchange for $200 million from Exelon. The money was to go toward removing trash and debris, planting underwater grasses and oysters, and studying how to address the sediment issue, among other programs.

But environmental groups were miffed, because Maryland previously issued a certification that would have required Exelon to pay $172 million per year — or reduce a specified amount of pollutants. That permit also required adjustments to the dam’s water flow operations, increased fish passage through the dam and increased monitoring of pollutant levels behind it. But Exelon took to the courts to fight the certification, and ultimately reached the $200 million deal during private settlement talks with the state.

Last month’s ruling by FERC largely solidified the settlement that environmental groups deemed lackluster. They contend FERC was obligated to require the certification and its decision isn’t lawful, since the Maryland Department of the Environment isn’t legally allowed to waive its certification and replace it with a settlement hashed out behind closed doors.

Anglers take hickory shad on spin tackle below the Conowingo Dam.

MDE did not respond to questions about the specifics of the appeal.

“FERC’s action is encouraging news for the Susquehanna River and the Chesapeake Bay after almost a decade of gridlock. Now we have a hard-fought environmental commitment from Exelon, enforceable under federal and state law and worth over $200 million,” Maryland Secretary of the Environment Ben Grumbles said in a statement. “It’s a good start but we know more action is needed, which is why we’re also working with states and the federal government to increase climate resiliency and prevent pollution upstream of and behind the dam.”

An Exelon spokesperson said Wednesday that the appeal by Waterkeepers Chesapeake, the Lower Susquehanna Riverkeeper, ShoreRivers and the Chesapeake Bay Foundation is without merit.

“The license marks the beginning of a new era of critical and much needed restoration, revitalization and funding that will have a positive and lasting impact on Bay health,” wrote spokeswoman Deena O’Brien in a statement. “We’d prefer to focus on Chesapeake Bay restoration efforts — not on protracted litigation that may serve to delay or deny these benefits at a time when they are most needed.”

The company argued previously that it’s not responsible for pollutants flowing down the Susquehanna that it didn’t create, and that the license includes sufficient measures for trash cleanup, oyster planting, waterfowl nesting and fish passage.

“These benefits would not have been achieved without a settlement agreement that resolved significant legal challenges to the water quality certificate that MDE issued,” O’Brien wrote last month.

At one time, the dam, which spans the Susquehanna River, a Chesapeake Bay tributary that flows between Harford and Cecil counties, trapped a significant amount of sediment and pollutants that would have flowed downstream.

The environmental groups also took issue with the commission’s contention during the licensing process that dredging sediments from behind the dam wouldn’t be worth the cost, since the benefits would be short-lived. While the commission estimated dredging would cost $267 million a year, one contractor provided an estimate of $41 million a year. They want Exelon to consider this solution.

Separately, the environmental groups are concerned about the operation of the dam’s fish lifts, equipment that’s meant to transport fish over the dam for spawning from April to June.

The larger of the dam’s two lifts was shut down last year from March to May, a key part of the spawning season for shad and herring, because of COVID-19. The lift must be monitored and invasive species removed by hand, and the company argued that pandemic protocols wouldn’t allow that.

“They deemed fish passage as nonessential business as part of them running the dam, and for me personally, that shouldn’t be the case because fish migration is absolutely essential for these species’ survival — now and for future generations,” said Ted Evgeniadis, the riverkeeper who monitors the Lower Susquehanna.

Shortly after the lift started running again in May 2020, Exelon reported that 21 invasive northern snakeheads were able to pass through the lift within a few days, and at the request of the U.S. Fish and Wildlife Service, the lift was shut down again for the remainder of the migratory season.

This year, with the migratory season already underway, the company is asking to shut it down again due to invasive species woes. The request had to be submitted again because of the new license, Exelon said.


Environmental groups, like the riverkeepers, say they’re confused about why Exelon can’t come up with a way to successfully sift out invasive fish, perhaps by hiring more staff. They agree that snakeheads and other invasive animals, like blue catfish, pose a significant risk since they steal valuable habitat and prey on native species. But that doesn’t mean all fish passage should be slowed, impairing reproduction for natives.

“They’re not going to be going anywhere anytime soon,” Evgeniadis said of the invasive fish. “So, again, this has to be addressed.”