Vienna residents were advised not to drink or cook with their municipal water on Thursday because five water samples, taken last year from throughout the water system, showed levels of C8 higher than a new advisory level for the chemical released earlier that day.

Vienna’s water comes from eight wells in three well groupings, and all three groupings were found to have elevated levels of C8 — a chemical linked to cancer and numerous other health problems — when tests were done in May and December of 2015.

In 2009, the U.S. Environmental Protection Agency set a provisional health advisory for C8 of 400 parts per trillion in drinking water.

Recent test results all fall below that limit.

On Thursday, though, after years of delays, the EPA set a long-term advisory limit of 70 parts per trillion.

Environmental groups and local lawyers have been pleading with the EPA to take action for more than 15 years, and many say the new level is still far too lenient in the amount of C8 it says is permissible in drinking water. They’re also critical that the limit is advisory only, and does not carry the force of law.

“[The] EPA must set a legally enforceable standard that will protect the millions of Americans drinking C8-contaminated water,” said Paul Brooks, a Vienna doctor and leader of the group Keep Your Promises DuPont. “This guideline falls short of that goal.”

Vienna’s water does not meet the new guideline. Water distribution sites were set up for the community early Friday.

C8, also known as PFOA or perfluorooctonate acid, was manufactured at DuPont Co.’s Washington Works Plant, south of Parkersburg in Wood County, and has contaminated the ground water there for years.

Of six tests done on Vienna’s wells in 2015, in compliance with EPA regulations, five were above the new limit, and the sixth was barely below.

The six tests found C8 ranging from 67.4 parts per trillion (just below the EPA’s new level) up to 129 parts per trillion, nearly double the EPA’s new level.

Other tests found levels of 76, 92, 99 and 106 parts per trillion of the chemical.

The testing was done in accordance with the EPA’s Unregulated Contaminant Monitoring Rule, which requires water systems to be tested for a different list of 30 contaminants every five years.

In 2012, PFOA and PFOS, a related chemical, were added to the list.

Out of more than 36,000 PFOA tests taken from about 4,900 water systems across the country, the EPA found 354 with evidence of the chemical, including those six in Vienna.

There were several more in Parkersburg.

Recent tests in Parkersburg found levels of PFOA of 72 parts per trillion (just above the EPA’s limit), as well as 13 parts per trillion and 33 parts per trillion.

Two tests in Parkersburg from 2014 found the chemical at levels of 63 and 41 parts per trillion, both below the EPA’s new level.

Parkersburg is one of two cities that, according to state officials, took action Thursday to shut down parts of its water system that had contaminated water.

The other city, Martinsburg, is on the other side of West Virginia from Parkersburg and Vienna, nowhere near the Washington Works Plant.

In 2014, tests at two Martinsburg water treatment plants found levels of PFOS in excess of the EPA’s new standard.

Out of 36,000 tests nationwide, only 285 found evidence of PFOS.

The Martinsburg tests found 74 parts per trillion of PFOS in February 2014, 86 parts per trillion in May 2014 and 79 parts per trillion in November 2014.

Two more recent tests found a combined total of 145 parts per trillion of PFOS and PFOA in Martinsburg’s water system.

Parkersburg and Martinsburg found chemical contamination in limited wells only and were able to shut off those wells while still providing regular water service, according to Walt Ivey, director of environmental health services for the West Virginia Bureau for Public Health.