The Bellevue City Council approved a measure on Monday that would help transform more than 27 acres of landfill into a city park.

After years of research and interviews, the City Council approved Portland-based firm Walker|Macy to take over the design, permitting and construction of the former landfill into what will be called the Bellevue Airfield Park.

Swing sets and base field fields, however, will be years away, as the city will spend the foreseeable future working the land and making renovations to existing below-ground systems to make the land ready for construction.

“It’s going to take many years to develop this property,” said Planning Manager Glenn Kost. “This project will be a little more difficult because it was a landfill. There’s a couple of different systems in the ground that need significant renovation.”

The majority of the acreage previously owned by Boeing at the Eastgate Area Properties at 2997 160th Ave. S.E. that has been allocated for the Bellevue Airfield Park was used as a landfill from 1951 to 1964. It was then used as an airfield until 1983.

Below the surface is a landfill gas migration system to collect the gas being emitted from the decomposing garbage. Although the amount of gas being produced has tapered off over the last 50 years, the system is still necessary and needs significant renovations, according to Kost.

Crews would also need to update the storm water management and water monitoring systems, including adding a barrier to prevent water from passing through the garbage remnants and polluting the groundwater.

The city did their due diligence before purchasing the property, said Kost, including an extensive study and master plan that was released in 2012.

“This is a very, very common use of completed landfills. It just happens to a use new to Bellevue,” he said.

Parks all over the world have been built over landfills, including locations in New York, Virginia, Colorado and even Seattle. The Washington State Arboretum was built over the Miller Street Landfill, a dump that ceased operation in the early 20th century.

Plans for the park have been slowly building since the city obtained the smallest chunk of property, measuring about two-and-a-half acres, from the Bellevue Utilities Department.

The purchase of more than 14 acres of landfill from Boeing gave traction to the project in 2002. The $3.5 million price tag, which Kost said was likely well below market value, counterweighted the projected cost of making the land usable.

“Yes, (the work) will be expensive, and that’s probably why we got such a good bargain on the property to begin with,” he said. “And it is likely less expensive to develop a park than housing or something else on this land.”

Given the scope of the needed work to make the land useable and the current lack of funding, construction is many years off.

The Parks department will go back to the City Council for funding in two to three years after Walker|Macy completes the design and permitting phase, according to Kost.