EPA says it has ‘no confidence’ in plan to address sediment pollution coming from behind Conowingo Dam

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The Environmental Protection Agency has “no confidence” that a plan to mitigate sediment pollution overflowing from behind the Conowingo Dam in northeastern Maryland will be completed, the federal agency said in a letter issued last week.

EPA came to the conclusion due to a “continued lack of dedicated funding” supporting the plan, the letter stated.


The Conowingo Watershed Implementation Plan was finalized over the summer, and lays out a series of methods to reduce pollution flowing down the Susquehanna River and out from behind the hydroelectric dam and into the Chesapeake Bay, including by planting forest buffers in key areas to reduce runoff.

The plan was crafted by a 15-member steering committee, including representatives from Maryland’s Department of the Environment and those of other nearby states. The committee crafted a strategy that calls for the establishment of a financing authority capable of collecting funds from the private and public sectors. But how exactly the funds will be obtained remains an open question.


Completing the Conowingo plan would mean offsetting the roughly 6 million pounds of nitrogen and 0.26 million pounds of phosphorous expected to flow from behind the dam, which weren’t accounted for in the EPA’s Chesapeake Bay cleanup plan established in 2010.

In his letter, dated Jan. 24, EPA Regional Administrator Adam Ortiz wrote that if the Conowingo funding issue is not addressed within 60 days, those nutrient totals will need to be added to the requirements placed on states via the larger cleanup plan, which has a 2025 deadline.

The Conowingo Dam is located along the Susquehanna River, near where it empties into the Chesapeake Bay.

In a statement, Matthew Rowe, chair of the Conowingo plan steering committee, said he welcomed the EPA’s letter.

“The upfront funding challenge has always been one of the biggest issues,” said Rowe, assistant director of the Maryland Department of the Environment’s Water and Science Administration.

When the multistate Chesapeake Bay cleanup plan — known as the Total Maximum Daily Load, or TMDL — was established in 2010, setting pollutant limits for the bay, officials expected the Conowingo dam to continue to trap a considerable amount of sediment flowing down the Susquehanna through at least 2025.

But studies have shown that the dam no longer trapping sediment as effectively because the area behind it is virtually full, and when significant storms take place, sediment stuck behind the dam is churned up and flows downstream. That sediment brings with it damaging nutrients, which overstimulate the growth of algae that hogs oxygen and sunlight, stealing from underwater life.

To compensate, the EPA has determined additional nutrient pollution reductions might be necessary for states in the bay’s watershed, including Maryland, Delaware, New York, Pennsylvania, Virginia, West Virginia and Washington, D.C.

That is, unless those states can come to an agreement to fund the new Conowingo watershed plan, which targets efforts at specific areas within the Susquehanna River basin that will have the greatest impact on reducing pollution flowing downstream. The Susquehanna watershed, which drains much of central Pennsylvania and parts of New York, accounts for about half of the fresh water flowing into the Chesapeake Bay.


Because it is targeted, and therefore may be more cost effective, the Conowingo plan is the preferred route, said Beth McGee, director of science and agricultural policy at Chesapeake Bay Foundation. Not to mention that for states like Pennsylvania, which is already behind the pace needed to achieve its 2025 goals, tacking on extra requirements may not be fruitful, she said.

“The notion of telling Pennsylvania, which is already really far behind in getting their pollution reductions, that they now need to do more on their own dime is not a winning strategy,” McGee said.

Shortly before the EPA letter was issued, Gov. Larry Hogan announced that $25 million in his proposed state budget would go toward Conowingo restoration projects, in addition to $6 million for an experimental dredging project for the dam’s reservoir.

“EPA and other federal agencies should lead as well and match or exceed state efforts on this longstanding problem,” wrote Jay Apperson, spokesman for the Maryland Department of the Environment, in a statement.

But environmental groups have long hoped that the dam’s operator — then Exelon — would shoulder more of the burden associated with the dam’s lost trapping capacity. Environmentalists say Exelon profits from using the waterway to create energy, and doing so has fundamentally altered the river’s flow — impacting migrating wildlife such as shad and eel, and changing the way sediment flows downstream. Now, the dam is managed by Baltimore-based Constellation Energy, which split from Exelon this week.

A set of requirements issued by Maryland in 2018 brought hope for environmental groups. It stated that Exelon would need to cough up $172 million annually to account for the nutrients overflowing from the dam. But after Exelon challenged Maryland’s requirements in court, the two parties came to a new agreement. Instead, Exelon would pay about $200 million total for wildlife restoration and pollution reduction efforts.


Many environmental groups hoped that the Federal Energy Regulatory Commission would reconsider requirements for Exelon as it reviewed a new 50-year license for dam operations, but the commission okayed Maryland’s decision, and the groups are now challenging that decision in court.

“Constellation agrees that solving the upstream pollution problem affecting the Chesapeake Bay requires each state to fulfill the commitments agreed to in the multistate Watershed Implementation Plan,” Constellation spokesman Paul Adams said in a statement. “While, unfortunately, those commitments remain unmet, we are already doing our part by providing up to $700 million in funding for environmental programs, projects and payments that directly benefit water quality, aquatic life and citizens living near the bay.”

Included in those funds are the settlement agreement with Maryland; up to $300 million for measures to improve fish passage through the dam from a settlement with the U.S. Fish and Wildlife Service; and $175 million for recreational facilities and wildlife based on a recommendation from FERC, Adams said.

In the current state legislative session, there’s talk of introducing a bill that, if passed, would charge hydroelectric dam operators annually for how much riverbed they’re using to store sediment, said Betsy Nicholas, executive director of the nonprofit Waterkeepers Chesapeake.

At a possible cost of ten cents per square foot, the proposal could cost Constellation millions each year, she said. And the funds would go toward projects meant to mitigate the dam’s impact. Such a bill has not been filed yet.

Meanwhile, dredging sediment from the dam’s reservoir is a complex path, partially because doing so may not actually remove pollutants from the water, and partially because it could disturb pollutants long ago buried by silt, Nicholas said. A study conducted recently found that granular bits of coal are buried in the sediment, alongside chemicals and nutrients. A dredging feasibility study from Maryland is due out later this year.


“If your bathtub is overflowing and you scoop a few buckets of water out of it, you’ve got a little while before it overflows again, but that’s it,” Nicholas said.

In order to fully solve the problem, you have to turn off the tap, she said. And that means reducing the flow of nutrients down the river, as called for in the Conowingo watershed plan.