The Navy has plans to clean up a chemical that has been creeping underground toward Oak Harbor for years from its old landfill and Superfund site, Area 6.

The Navy has requested to buy an easement from the City of Oak Harbor to install underground pipes along State Highway 20 to treat contaminated water at its new facility, City Engineer James Bridges told city council members on Sept. 15.

The chemical known as 1,4-dioxane is moving southeast in groundwater — toward Oak Harbor — from part of a capped landfill on Ault Field known as Area 6. The Navy began testing for 1,4-dioxane in private wells in 2005, according to a Whidbey News-Times article published at the time. No drinking water was affected since city water is piped in from the Skagit River.

The chemical 1,4-dioxane is used as a stabilizer in certain “chlorinated solvents, paint strippers, greases and waxes,” and is found at many federal facilities, according to a fact sheet from the Environmental Protection Agency. The EPA has found 1,4-dioxane “likely to be carcinogenic to humans” and said it moves quickly in groundwater.

The chemical, 1,4-dioxane, should not be confused with a group of chemicals called dioxins, which are highly toxic and not made or used commercially in the United States, according to the EPA.

The Navy proposed to buy the easement for $23,325.

The easement would be used to install four or five pipes running north along Highway 20, starting close to where Northeast 16th Avenue and West Cemetery Road cross the highway.

The pipes would continue north until crossing back onto Navy property, where the water would be treated.

The Navy’s contractor began building part of the system on federal property in August, according to Mike Welding, a Navy spokesperson. Five groundwater extraction wells and the pipes will follow once the easement has been finalized, he explained.

There was some concern among the state, Island County and the city about the proximity of the Navy’s pipes and treatment facility to Highway 20 in case the road should ever be expanded, Bridges explained.

The city and the county also have plans to construct a pedestrian and bicycle path in the area.

Bridges said the plan for the easement is the best solution.

There will be approximately 17 feet between the state highway and edge of the Navy’s underground pipes, Bridges said.

The city’s bicycle path would be about two to three feet away from the Navy’s trench.

Pollutants such as 1,4-dioxane and millions of gallons of oil, acids and other sludge was dumped in the landfill at Ault Field for years. It was designated as a Superfund site by the federal government in 1992, meaning it will take years of work to clean up the site.

“The amount of this pollutant is such that it’s going to take about 50 years,” Bridges said.

Oak Harbor City Council is scheduled to make a decision about the easement at a meeting Sept. 23.