Top sewer plant choice on the Seaplane Base
July 3, 2008 · Updated 11:35 AM
In ten years at the latest, the city of Oak Harbor will need to expand its sewage treatment capabilities.
But with possible new regulations and the age of the plant in Windjammer Park, that need may occur much sooner. And planning for a new treatment facility can take years.
The city, therefore, set up an ad hoc committee more than a year ago to look at the future of wastewater treatment in the city. City Engineer Eric Johnston presented their two-part conclusions at the City Council meeting last week.
The top recommendation is to build either an activated sludge with filtration or membrane bioreactor plant at the Seaplane Base lagoon site. They are estimated to cost $34 or $50 million, respectively. The city runs the lagoon treatment system, which treats sewage from Navy housing and facilities on the Seaplane Base. The city and Navy have a complicated joint ownership of the lagoons, which could pose problems.
Johnston said the committee recommended that the city negotiate an enhanced use lease at the lagoons with the Navy, guaranteeing that the city has long-term access to the area before expending millions of dollars on a facility. If the issue isnt resolved with the Navy in the next three or four years, the group recommends dropping the option.
If that occurs, Johnston said, the committee recommends instead expanding the plant in the waterfront Windjammer Park by building on a membrane bioreactor plant. Its estimated to cost $24 million.
The idea of expanding the facility would seem to fly in the face of the Windjammer Plan for redeveloping downtown Oak Harbor and the waterfront. One of the consultants prominent recommendations was to remove the aesthetically-challenged, often-stinky plant from the midst of Windjammer Park.
But Johnston pointed out that committee members visited several state-of-the-art facilities and found they can actually be attractive buildings. He said the Edmonds treatment plant, for example, hosts weddings, is near a city park and generates few odor complaints.
Sewer treatment plants dont have to look like sewer treatment plants, he said.
Also, Johnston said an expanded facility at Windjammer would make sense because the city could use the treated gray water in the park.
The committee looked at building a sewer treatment plant at the Old City Shop at the north end of City Beach Street, but they found that it was too small to provide treatment capacity for 20 years.
While the costs of an expanded system will be large, Johnston pointed out that the local environment will definitely benefit. The state Puget Sound Action Teams report, State of the Sound 2007, says that nutrient and pathogen pollution are major concerns and it identifies wastewater treatment plants as primary sources of these pollutants.
Johnston said nitrogen limits in effluent discharged by plants are very likely to be enforced in the near future. The city would have to build a facility that uses an activated sludge process or a membrane bioreactor to comply with such a regulation.
The citys plant at Windjammer Park complies with all the states current regulations and even has won awards but its old, worn and doesnt deal with nitrogen. It treats sewage with rotating biological contactor tanks and is one of the last such plants in operation in Western Washington.
In a visual demonstration at the council meeting, Johnston held up a bottle of the murky water that the city discharges along side crystal-clear water from a facility with newer technology.