There's something unseemly about Oahu, marketed worldwide as an island paradise, shipping piles of garbage to the mainland, to be dumped in somebody else's backyard.

But that's the scenario unfolding this week, as the private company Hawaiian Waste Systems began compacting and shrink-wrapping bales of trash at its $10 million Campbell Industrial Park facility.

The garbage eventually will be loaded onto barges, shipped to Washington state and dumped in a landfill there.

The process, which got under way two months late due to a contractual dispute with the city, is expected to divert about 2,000 tons of trash a week that would otherwise have gone to the Waimanalo Gulch Landfill.

But even the contractual maximum of 100,000 tons a year (shipped at about $100 per ton) is a mere fraction of the 1.75 million tons of garbage generated annually on Oahu.

Honolulu Mayor Mufi Hannemann insists that Oahu will ship trash elsewhere only temporarily, until a third boiler is operational at the city's HPOWER waste-to-energy plant by late 2011 or early 2012.

But taxpayers can be forgiven their suspicion that the three-year shipping contract likely would be continued.

After all, the announcement that the trash would be shipped came just a day after the state Land Use Commission again voted to again extend the use of Waimanalo Gulch, years after earlier city administrations had promised to end dumping at the Leeward Oahu site.

The mayor had wanted a 15-year extension, but got less than three; after July 31, 2012, the landfill is to take only ash and residue from HPOWER, the commission decided.

That short extension, coupled with Hannemann giving his word that the mainland trash shipments would be temporary, exerts pressure on all Oahu residents to pare down the growing mound of trash and ease the burden on the landfill.

The city government should swiftly expand its curbside recycling program to more neighborhoods, make sure the third boiler at HPOWER is built on schedule and identify a new landfill site so the public can reasonably assess the pros and cons of building a new dump or, as the mayor seeks, further extending the life of the old one.

Consumers, or wasteful ones anyway, should not blithely continue their ways, assuming that every deadline will be extended.

There is a limit to the amount of trash that Oahu can handle, and the overflow is a blight not only to the landscape, but also to Hawaii's image as a tourist paradise.