Maryland’s Conowingo Dam has become the center of a legal battle between state environmental regulators and the energy company that owns it.
Chicago-based Exelon Corp. is suing the Maryland Department of the Environment over conditions imposed in a water quality certification that is part of the dam’s federal relicensing process, the Bay Journal reported. The company filed suit last week in the U.S. District Court for the District of Columbia and the Circuit Court for Baltimore City. It also appealed to the state environmental agency, asking that it reconsider its decision.
The conditions imposed by the state create an “unfair and onerous burden,” Exelon said in a statement.
Among other conditions, Exelon needs to reduce the amount of nitrogen and phosphorus pollution that flows past the dam annually by millions of pounds, state regulators said in the certification. Alternatively, the company can pay the state more than $170 million per year. That amounts to more than $7 billion over the term of its license and “exceeds, by orders of magnitude, the economic value of the Conowingo Project as an operating asset,” according to court documents.
Exelon contends that the conditions in the certification were designed to “leave Exelon with no choice but to pay Maryland a massive annual fee,” according to court documents filed by the company.
Doug Myers, Maryland senior scientist with the Chesapeake Bay Foundation, sees other options for Exelon to reduce pollution in the river.
“If they were to form a partnership with the other states and work on agricultural best management practices upstream in the watershed, in the Susquehanna, they could do that for a fraction of the cost,” Myers said.
Exelon also said in a statement that the dam itself doesn’t produce pollution.
The 90-year-old dam used to effectively remove sediments from the Susquehanna River. But over the years, sediment and nutrients have built up behind the dam.
“It has effectively lost its removal capacity for sediments,” said William P. Ball, an environmental engineering professor at Johns Hopkins University’s Department of Environmental Health and Engineering. “For long-term modeling purposes, it’s best to treat the dam as if it were not there for removal of sediments and phosphorus.”
The dam has never been very good at removing nitrogen, he added.
Nitrogen and phosphorus can end up in the river from sources such as agricultural runoff and sewage treatment plants. These nutrients can cause excessive amounts of algae to grow. When the algae dies and decomposes, it leads to lower dissolved oxygen levels in the water — a problem for other forms of marine life.
The state environmental agency stands by the water quality certification it issued in April.
“We will vigorously defend our comprehensive Conowingo plan to restore the river and the bay,” the Department of the Environment said in a statement.