CHARLESTON, W.Va. (AP) — A group of Parkersburg residents is asking a federal appeals court for permission to pursue its effort to collectively press a water contamination lawsuit against DuPont.

Thousands of Parkersburg residents want to sue DuPont as a group, claiming the city’s water was contaminated by perfluorooctanoic acid, known as PFOA or C8. The company uses the chemical at its nearby Washington Works plant to manufacture Teflon. The residents were asking that DuPont clean up the water and fund a medical monitoring program.

In September, U.S. District Judge Joseph R. Goodwin ruled the residents could individually sue DuPont, but they had failed to meet the requirements to be certified as a class, in part because they couldn’t prove that all were affected the same way and because they were not “sufficiently cohesive” to be a class. Goodwin suggested residents could pursue other approaches.

Lawyers representing the residents have asked the 4th Circuit Court of Appeals for permission to appeal now rather than wait for a final outcome of the case, which is still pending before Goodwin.

The residents argued they should be allowed to obtain class-action status because DuPont settled a state-filed class-action lawsuit involving the same chemical in February 2005. That lawsuit involved Ohio and West Virginia residents who lived in six water districts near the Washington Works plant.

As part of the 2005 settlement, DuPont agreed to fund a health screening project to determine if there are any long-term health issues related to C8.

The request to appeal Goodwin’s ruling was filed Wednesday, the same day a three-member science panel released the first of its findings from the health screening. The panel noted that people who lived closest to the plant had the highest levels of C8 in their blood, and those with the highest levels also had high cholesterol levels. Given the data, the panel could not make a link between C8 and diabetes.

DuPont spokeswoman Robin Ollis said Thursday that Goodwin “made an appropriate ruling in denying class certification. We believe that plaintiff’s request for permission to appeal is without merit.”