Environmentalists take their fight against Conowingo Dam license to federal court

Environmental groups have asked a federal appeals court to weigh in on a license granted to Maryland’s Conowingo Dam earlier this year, due to their concerns about pollution flowing through it.

The groups, including Waterkeepers Chesapeake and the Chesapeake Bay Foundation, filed a petition urging the appeals court for the D.C. District to reverse the Federal Energy Regulatory Commission’s decision this spring to grant Exelon a new 50-year license to operate the hydroelectric dam. They argue the new license ignores some of the dam’s most damaging environmental impacts, and doesn’t do enough to compel Exelon to address or compensate for them. That, they contend, is a violation of environmental laws.


The dam, located along the Susquehanna River near where it empties into the Chesapeake Bay, has trapped a large amount of sediment and debris for years. But now, the reservoir behind it is largely full, so pollutants continue downstream and into the bay. And when big storms come, large amounts of nutrients are released all at once, burying aquatic life and spurring the overgrowth of algae, which sucks oxygen from the water and creates dead zones in the bay.

Back in 2018, Maryland environmental officials announced they intended to charge Exelon up to $172 million each year unless it came up with a plan to trap as much nutrient pollution as it had years ago. But when Exelon challenged them in court, the state backed down, arriving at a settlement that would charge Exelon a total of $200 million for cleanup efforts.


The environmentalists argue Maryland couldn’t abandon its original requirements on Exelon in favor of a closed door agreement with the company. And therefore, they said in Thursday’s filing, the court should order FERC to include Maryland’s original requirements in the 50-year license.

Conowingo Dam, located along the Susquehanna River near where it empties into the Chesapeake Bay, is the focus of a lawsuit by environmentalists who say large amounts of pollution are trapped behind the dam.

The environmental groups initially appealed to FERC to reconsider the ruling, but the commission didn’t act, which amounts to a denial.

In a statement, Exelon spokeswoman Deena O’Brien said the company supports FERC’s ruling, which requires Exelon to contribute to other environmental programs focused on restoring aquatic life, among other items.

“This new license provides immediate and significant help to the Chesapeake Bay including up to $700 million in environmental programs, projects and payments that directly benefit citizens, water quality, and aquatic life in the State of Maryland,” O’Brien said.

Celeste Miller, a FERC spokesperson, declined to comment on the pending court proceedings.

In the meantime, environmental groups are left to worry about what a substantial storm, like Hurricane Agnes in 1972, could do to the bay ecosystem if the dam’s problems aren’t addressed. That storm caused extensive flooding, forcing the dam to open its gates and release years worth of pollutants at once, burying ecosystems downstream. Now, the dam holds even more sediment behind those gates.

“When we get that next very large storm, which is going to happen over this next 50-year license term, the Chesapeake Bay — mark my words — it’s going to be dead if what’s behind this dam is not mitigated,” said Ted Evgeniadis, riverkeeper for the Lower Susquehanna, during a news conference Thursday.

That mitigation could come in the form of dredging the dam’s reservoir to remove some of the sediment trapped there, a solution that environmentalists argue could be cheaper than originally estimated.


When contacted by environmental groups, one company offered to dredge the dam hydraulically for $41 million a year, Evgeniadis said.

But without the requirements from Maryland’s water quality certification from 2018, that kind of investment from Exelon seems unlikely to occur, said Morgan Johnson, a staff attorney with Waterkeepers Chesapeake. Instead, cleanup costs associated with the pollution could fall to taxpayers, she said, all while Exelon profits from the waterway.

“If Maryland’s certification was upheld as valid — as it is — the funds outlined as necessary to make those vital reductions would be there, rather than passed off to folks in Baltimore and the farmers on the Shore,” Johnson said.

Even now, storms are causing significant problems for the bay, some of which, the environmentalists say, can be traced back to the dam on the Susquehanna, among the Chesapeake’s largest tributaries. So-called “scour events,” which churn up pollutants from Pennsylvania and New York trapped behind the dam and send them down the river.

“Any time it rains and we have those gates open, the Coast Guard is on the marine radio every couple minutes warning about what’s floating down in the rivers,” said Zack Kelleher, the riverkeeper for the Sassafras, another bay tributary south of the Susquehanna.