The Maryland Dept. of the Environment has reached a deal with Exelon Generation Co. LLC in which the electric utility company will spend more than $200 million over 50 years to improve the water quality of lower Susquehanna River and Chesapeake Bay

The agreement, announced on Oct. 29, now will be reviewed by the Federal Energy Regulatory Commission. [View copy of settlement agreement here.]

Elements of the plan will become part of Exelon’s previously submitted application with FERC to renew the company’s license for the 90-year-old Conowingo Dam and hydroelectric plant on the lower Susquehanna, the bay’s largest tributary. The company is seeking a 50-year license renewal.

The state and the company praised the outcome of their negotiations. Maryland Gov. Larry Hogan [R] in a statement called the settlement “a significant and positive step.”

Chris Crane, Exelon president and chief executive officer, said in a statement, “The agreement is designed to substantially improve water quality while ensuring Maryland’s largest source of renewable energy continues to deliver environmental and economic benefits for the next generation.”

But environmental groups question whether the new deal’s provisions are strong enough to make the river and bay water cleaner. Betsy Nicholas, Waterkeepers Chesapeake Executive Director, said in a statement that provisions for Exelon to pay Maryland for such things as restoring mussel habitat, “are merely statements of intent and they are not binding.”

Nicholas added, “There are no assurances that the agreement will actually result in improvements to mitigate the impacts of the dam on Maryland’s water quality.”

Exelon’s investment—much of which would be payments to the state for various projects—includes: $47 million for projects aimed at improving the river's and bay's ability to withstand storms and other extreme weather; $41 million to increase removal of debris that moves down the river; and $25 million to restore mussels, including Exelon-owned land for a new 40,000-sq-ft mussel hatchery.

Also on the list are: $19 million for other bay water-quality projects, such as cover crops and forest buffers; $12 million to help fund Maryland state agencies’ implementation and oversight for the agreement; and $11 million to make changes to smooth the migration of fish and eels.

The projects in the Maryland-Exelon pact supplement a 2016 agreement between the company and the U.S. Fish and Wildlife Service. That pact includes improved fish passage facilities at the dam, at a cost that Exelon estimated at more than $300 million.

Maryland and Exelon have been tussling over environmental issues at the dam for months. Last year, the company  filed a challenge in federal district court against the state's water quality certification for the dam under the Clean Water Act. [See ENR story 6/6/2018).

Under the new agreement, Exelon is “conditionally” withdrawing that petition before the court, with the condition being FERC approval of the settlement.