CHIMACUM — Marrowstone Island residents who wanted a public water system got their wish Wednesday when Jefferson County Public Utility District commissioners unanimously approved an island-wide potable water system.

The vote, however, doesn’t mean the controversy over the project is ended, as opponents of the plan are threatening legal action to stop it.

“We are prepared to have the courts decide what is fair and democratic,” Wayne Chimenti, a member of the Conserve Water First group opposed to the plan, said after the commissioners voted 3-0. “Luckily, your record is so blatant that a court case will be easy.”

“We’ll see where it goes,” said Conserve Water First representative Ray Harker when asked if the anti-water system group would sue.

The estimated $4.4 million project, known as a local utility district, will carry an assessment of about $6,000 for residents who will connect to the water system and $1,500 for those who have wells certified by the county health department.

Assessment and installation costs from the line to residences can be spread over 20 years, utility district officials said.

The decision was a significant highlight of the two-year-old debate that has polarized pro- and anti-water system factions in the east Jefferson County community.

While the commissioners’ decision to move forward with the water system was unanimous, it appeared to be a difficult one.

David Sullivan, who represents the central portion of Jefferson County that includes Martrowstone Island, said last week he would vote against the system because more than 40 percent of parcel owners were against the project. He said he changed his mind after looking at a 60 percent to 70 percent approval rate for the system as a mandate to move ahead.

Sullivan called “archaic” the process used to determine whether a local utility district is formed. Under state law only people against the project needed to formally file a protest (vote) and residents favoring the idea needed to do nothing.

“It didn’t allow people to assert themselves and say ‘I’m for it,”‘ Sullivan said.