They claim the city's water was contaminated by C-8, a chemical the company uses at the Washington Bottom plant to manufacture Teflon.

Last month a federal judge ruled the residents could individually sue DuPont, but said he couldn't certify the case for class-action status on the basis of potential harm.

DuPont has already settled a 2001 multi-million-dollar class-action case involving the chemical, with residents living in six water districts near DuPont's plant.

The newest request was filed with the 4th Circuit Court of Appeals on Wednesday.