Robert B. Goebel General Contractor Inc., of Spokane, has begun work on the $7.6 million first phase of an estimated $43.5 million project to build a wastewater treatment plant for the city of Airway Heights.

Airway Heights, which doesn't have its own wastewater treatment plant, contracts with the city of Spokane to treat its effluent at the Riverside Park Water Reclamation Facility, on the Spokane River at 4401 Aubrey L. White Parkway. Airway Heights began planning in 2003 to build its own wastewater treatment plant in anticipation it eventually would use up the treatment capacity for which it had contracted with the city of Spokane, says Albert Tripp, Airway Heights city administrator.

The West Plains city secured environmental permits last summer to build a wastewater treatment plant and has identified grant and loan funding to go ahead with the project, Tripp says. System users could see higher rates, depending on how much of the facility the city is able to pay for with grants, Tripp says.

The facility will be located within the city of Airway Heights on a 75-acre parcel bordered by 21st Avenue on the north, Russell Street on the east, McFarlane Road on the south, and Lawson Street to the west.

Goebel's bid for the first phase of the project was 32 percent lower than the engineers' estimate of $11.2 million, says Tripp. The city plans to seek bids soon for the next phase of work on the project.

That work, which it's calling phase 1B, is to begin later this year and is expected to cost about $32.5 million, Tripp says. The city expects to award a contract for it in May. A later phase is planned to increase the plant's capacity to 1.5 million gallons a day.

The first phase of work is expected to take about a year to complete, and site work began last week, Tripp says. The first phase includes construction of sewer lines, administrative buildings, tanks, an anaerobic process basin, and a 2 million gallon reclaimed water storage tower, all on the treatment-plant property.

The second phase of work will consist mostly of construction that won't be on the treatment-plant property and will include installation of water lines that will carry treated wastewater to various commercial and industrial customers for irrigation and other uses. That phase also will involve construction of two pumping stations, Tripp says.

The wastewater treatment plant will serve about 1,600 customers and will be able to treat up to 1 million gallons of wastewater a day. A number of potential users are interested in the treated reclaimed wastewater the plant will produce.

Those potential customers include Fairchild Air Force Base, which would use the water to wash down airplanes and runways; the Washington state Department of Corrections, which would use the water for irrigation; and Spokane County, which would use the water for irrigation at its Spokane County Raceway.

The city of Airway Heights has requested funds from the Washington Legislature to help pay for some of the long-term cost of the project, and could potentially get some federal stimulus funding through the Washington state Department of Ecology, Tripp says.