Two homeowners near a Dominion Virginia Power plant in Possum Point are suing the utility company for several million dollars, alleging that coal-ash water dumped into a Potomac River tributary caused their drinking wells to be contaminated with toxic metals.

The lawsuits, filed in Prince William County Circuit Court this week, claim that Dominion was being negligent when it released 27.5 million gallons of untreated coal-ash water into Quantico Creek in 2015.

State environmental authorities have said that the release of the water was legal. The plaintiffs, who live in Dumfries, say they were worried about their health because they used the wells for months before learning that they had been contaminated.

Daniel Marrow and his family are seeking $6 million in compensatory damages, while Brian G. West is seeking $3 million, the lawsuits state.

Dominion spokesman Robert Richardson declined to comment on the lawsuits.

Last year, Dominion offered to pay to connect local residents to the Prince William County water system because of the well contamination. Three of the eight affected residents have accepted, Richardson said.

Dominion, which stopped using coal at the Possum Point site in 2003, is awaiting state approval to bury 1 million tons of treated coal ash there.