The city of Seattle could take Harbor Island off its list of potential sites for a garbage-handling facility because the Port of Seattle might need the property for its growing shipping business.

Seattle Public Utilities has been looking for a site to build a "solid waste intermodal transfer facility," a place where the city's garbage would be compacted, packed into shipping containers, and then loaded onto railroad cars for shipment to a landfill in Eastern Oregon.

King County has plans to build a similar facility and has already purchased the old Fisher flour mill on Harbor Island.

The county and city briefly considered building a joint-use facility but the two local governments are on different timelines. King County doesn't need such a facility until the Cedar Hills landfill is full, which isn't expected to happen for 10 years. However the city of Seattle's need for a garbage transfer facility is much more pressing.

Two of the four sites the city has been studying are on either side of the former Fisher mill. If the Harbor Island sites are ruled out, the city would look more closely at the two other potential sites, which are in Georgetown, said Henry Friedman, project manager for the city's solid waste intermodal transfer facility.

Meanwhile the Harbor Island sites, which are located on Terminal 10, could be leased to other interested parties.

"We are actively marketing the property," said David Schaefer, a Port of Seattle spokesman. The Port, which owns the Harbor Island sites being considered by the city, wants to keep the properties and lease them for five to 10 years in case the land is needed later to store shipping containers.

Seattle Public Utilities is looking for a site where it could operate for a half century, Schaefer said.

"Our fear is we might need it for containers in the future," he said. Terminal 18, the largest container terminal in the state, is nearby.

The sites in question are part of Terminal 10. The water there isn't deep enough for large container ships to dock, but the site could be used to store additional containers, a rail-loading facility or it could be suitable for smaller ships and barges, Schaefer said.

"You can't say it would never be sold to the city, but that isn't what we're looking at at the moment," he said.

Meanwhile the environmental impact statement for the city's potential sites was made public recently and it indicates the environmental impacts would be similar at each site being considered.

One of the main aspects of the environmental impact statement pertained to what effects such a facility would have on traffic. The study showed traffic impacts would be greatest at a site in Georgetown, west of Airport Way and south of Edmunds Street.

Tim St. Clair can be reached at 932-0300 or tims@westseattleherald.com