PARKERSBURG — This marks the two-year anniversary since the first C8 water filtration plants went on line.

Five plants are operational with construction on a sixth to possibly begin this summer.

DuPont officials say the systems have been “effective and efficient” and C8 levels at those sites are below the allowable community exposure standards for the chemical.

In a phone interview Wednesday with The Parkersburg News and Sentinel, David Boothe, global business manager, DuPont Fluoroproducts, said the first two granular activated carbon water filtration plants were constructed in Belpre and Pomeroy, having gone on line about two years ago. Since that time, plants at Tuppers Plains and Little Hocking, Ohio, have become operational.

The chemical ammonium perfluorooctanoate, also known as C8 is used by DuPont Washington Works in the manufacturing process of nonstick and stain/water resistant coatings. Construction of the water filtration plants was part of the settlement in a class-action lawsuit brought by area residents against DuPont Washington Works. The plaintiffs alleged the C8 DuPont discharged into area water supplies caused health problems. Also as part of the settlement, a major health study of nearly 70,000 people in the six affected water districts was undertaken which included blood testing for C8. A three-member science panel was appointed by the court to examine the health information and test results from the health project participants as well as health information on DuPont employees and determine whether there is a probable link between C8 and human health.

DuPont has said it will phase out use of C8 in its plants by 2015.

In the settlement, DuPont agreed to pay for installation of filtration systems for the water supplies in the six affected districts that were part of the civil action lawsuit: Belpre, Little Hocking, Tuppers Plains and Pomeroy in Ohio, and Lubeck and Mason County in West Virginia.

“We now have two years of experience with these systems and we have learned a lot about how they work and how they behave. Overall, our experience has been good, they are working extremely well. We are getting results from the treatment that indicate C8 levels are far below any of the regulatory guidelines for C8,” Boothe said, noting most levels are at “non-detect.”

“We think the success seen so far is a good indication of the design, construction and operation of the units in general. We have five out of the six on line. The final two treatment units will be installed in Mason County, W.Va. The design is done for the last unit and has been approved by the West Virginia Department of Health and Human Resources. By mid-March we will be submitting our certificate to the West Virginia Public Service Commission for review and approval and if all goes as expected, we hope to begin construction in early summer and have the Mason County facility operational within a few months after that,” Boothe said.