Groundwater near base tests safe for dioxanes
July 3, 2008 · Updated 4:56 PM
Whidbey Island Naval Air Station announced the finding of no harmful levels of 1,4 dioxane in groundwater tested from local wells.
The Navy, in a coordinated effort with the Environmental Protection Agency, Washington State Department of Health and the Island County Health Department has conducted three rounds of sample testing over the past year on privately-owned wells adjacent to base property.
The chemical, 1,4 dioxane, is a chemical once employed by the Navy to stabilize degreasing solvents applied to aircraft parts prior to painting or repair.
It is not, however, the same chemical as the highly toxic compounds known as dioxins, according to the news release issued last week.
How much of the 1,4 dioxane was found in well water?
Over the past year, quarterly sampling for 1,4 dioxane has shown levels below the Model Toxics Control Act cleanup level of 7.95 parts per billion, said Marie Piper, Island County Public Health environmental health specialist, as well as below a more stringent guidance level of 3 parts per billion.
Yet 1,4 dioxane has potential risks. The U.S. Department of Health and Human Services considers the chemical as reasonably anticipated to be a human carcinogen. Studies show that laboratory rats and mice that drank water containing 1,4 dioxane during most of their lives developed liver cancer.
Scientists are debating the degree to which the findings in rats and mice apply to exposure situations commonly encountered by people.
The highest area of local concern is an old landfill on NAS Whidbey property known as Landfill Area 6 near the corner to Ault Field Road and Highway 20 which has seen concentrated efforts to remove other contaminants over the past decade.
For the past 10 years, the Navy has been treating the groundwater beneath Landfill Area 6 to remove the chlorinated solvents trichloroethylene and 1,1,1-trichloroethane from the groundwater and return the treated water to the underground aquifer.
The EPA initiated the testing for 1,4 dioxane in response to some areas of the nation having dangerous elevated levels.
Were working closely with the Navy base, Said Nancy Harney, EPA project manager, and will stay close with them the whole way.
The Navy will continue quarterly sampling for at least another year to check long-term trends.
Another round of sampling is scheduled for later this month, said Piper.