Hawaiian news outlets have reported that the first shipment of garbage from Honolulu may be only days away from setting sail, headed to a Washington landfill near the Columbia River. Hawaiian Waste Systems, a Seattle-based company with a contract to ship 150,000 tons of waste from Honolulu to the Roosevelt Regional Landfill, told reporters it believed final USDA approval was imminent. The process has already dragged on for years and sparked controversy across the Pacific.

But the Yakama Nation, which has treaty rights to fish in the Columbia River, is continuing to raise protests over what it considers “exotic” garbage that could contaminate the region.

Yakama Chair Harry Smiskin says the federal government is obligated by treaty to consult with the Yakamas about anything that might adversely affect the land around the landfill, which the tribe ceded in 1855. According to Smiskin, the tribe is concerned that “imported” rodents from Hawaii could contaminate the groundwater and river, while Hawaiian fruit flies could decimate farms on the reservation, which lies about 50 miles north of the landfill.

Environmentalists have raised similar concerns—which the USDA eventually discounted after multiple reviews over five years, according to agency spokesperson Lawrence Hawkins. In May, the USDA gave Hawaiian Waste the go-ahead to start shipping the garbage. But the agency suspended its approval earlier this month, just as the company was about to load bales of trash onto a barge, after inspectors found tears in the plastic covering.

Hawaiian Waste Systems president Mike Chutz, talking by phone from Honolulu last week, said the company rewrapped the bales and had received word from the USDA that it will lift the suspension any day now. He pointed out that the tribe had an opportunity to comment when the USDA was conducting its review, but waited instead “until the very, very last minute to exercise its right” to be consulted.

It’s unclear, however, what power the Yakama Nation really has over the matter. Hawkins says it’s a legal question he can’t answer.

But he adds that the USDA intends to “fully explore” the tribe’s concerns. Meanwhile, Honolulu Mayor Mufi Hannemann, who is running for governor, has been threatening to call off its contract with Hawaiian Waste if it doesn’t get the garbage moving, and soon.