Where do you want the Oak Harbor sewer plant?

The public will have a chance to weigh in on the location of a proposed $70-million wastewater treatment facility in Oak Harbor next week.

The public will have a chance to weigh in on the location of a proposed $70-million wastewater treatment facility in Oak Harbor next week.

City officials and representatives from Carollo Engineers, a national engineering firm with an office in Seattle, will host a special meeting Monday, Dec. 6, from 6:30 to 8 p.m. at Skagit Valley College’s Hayes Hall. A quorum of the City Council is expected to attend.

While several details of the proposed project will likely be discussed at the meeting, City Administrator Paul Schmidt said the officials are hoping for one thing in particular from the public.

“We’re really seeking input about where to build,” he said.

The city is looking at the new facility to satisfy a recommendation in Oak Harbor’s 2008 Comprehensive Plan to replace its two existing facilities at Windjammer Park and the Seaplane Base.

While both are keeping up with the city’s current demand, they are aged and city officials do not believe they will be able to handle ever-more stringent water quality standards being passed down from the state.

Carollo was hired by the City Council in August at a cost of $1.09 million to create a preliminary engineering and facilities plan for the proposed treatment plant. The plant, which is hoped to be built and in operation within seven years, is expected to cost about $70 million.

The contract tasks Carollo with developing a range of alternatives, identifying improvements to existing outfalls, investigating effluent reuse opportunities, creating a facilities plan, conducting an environmental review of the proposed alternative, and effectively communicating with the public.

Schmidt said that a number of different sites scattered across the city, from Goldie to Swantown roads, are being considered so location will be the primary focus of the meeting. However, wastewater treatment technologies vary and can effect both cost and size so that also will be discussed.

City Engineer Eric Johnston confirmed that the two technologies being considered are “activated sludge” and “membrane bio reaction.” Both have their own pros and cons. Activated sludge is older, takes up nearly twice the space as membrane bio reaction facilities — six acres compared to three — and are generally less effective, he said. However, they can also be considerably cheaper to build.

Johnston said this is just the first of series of public meetings that will occur over the next year and a half discussing details of the proposed facility.