Wasco County targeted in renewed push to block Portland Harbor sediment disposal

Dust blowing from the Wasco County Landfill traffic in March.

Meanwhile, alternative Ross Island proposal emerges

The Dalles, Ore., April 12, 2026 — A regional environmental group is escalating efforts to keep contaminated sediment from the Portland Harbor Superfund Site out of Wasco County, as a separate proposal in Portland could offer an alternative to shipping the material east.

Neighbors for Clean Air announced new campaigns in Portland and Wasco County urging local elected officials to oppose any plan that would send Superfund sediment to the Wasco County Landfill.

The group, which is an Oregon-based environmental advocacy organization that works to reduce air pollution and protect public health, is calling on the Wasco County Commission and The Dalles City Council to formally advocate against the project.

Neighbors for Clean Air say accepting the material is a bad choice, citing concerns about increased truck traffic, air pollution and potential long-term impacts to local communities.

The renewed push builds on concerns raised earlier this year when Wasco County, along with landfill sites near Arlington and Bickleton, were identified as possible destinations for contaminated sediment removed from Portland Harbor.

Local estimates previously suggested roughly 19,000 truckloads could move through the region over a period of months, raising alarms about road safety and environmental impacts.

Neighbors for Clean Air said it plans to launch a public petition in the coming weeks and will expand outreach through local media and community networks. A public meeting is scheduled for May 11 in The Dalles, with legal experts from the Northwest Environmental Defense Center expected to attend.

Despite its name, the Wasco County Landfill is a privately operated facility managed by Waste Connections Inc. under a franchise agreement with Wasco County. The county and the City of The Dalles retain regulatory and contractual authority over the landfill’s operation, including franchise terms and waste flow policies, but day-to-day operations are handled by the private operator.

Neighbors for Clean Air is an Oregon-based environmental advocacy organization that works to reduce air pollution and protect public health through community organizing, policy advocacy, and public education.

Meanwhile: Ross Island proposal under discussion

At the same time, a separate concept being explored in the Portland area could significantly change how and where the sediment is handled.

Global consulting firm Tetra Tech has approached the U.S. Environmental Protection Agency with an idea to transport contaminated sediment a short distance upriver by barge and use it to fill the Ross Island quarry.

The proposal is tied to an investor group, Heronpark LLC, which is seeking to acquire the island. The plan would involve placing sediment into the 130-foot-deep lagoon left by decades of mining, potentially accelerating cleanup of the Superfund site while contributing to restoration of the island, according to OregonLive.com

As of April 2026, however, no formal written proposal has been submitted to the EPA, and the concept remains under consideration rather than an approved plan, according to OregonLive.

Reporting also notes that Heronpark LLC shares an address with Tetra Tech, and the proposal could create financial incentives by allowing investors to collect fees for accepting the material while reducing transportation costs for responsible parties.

The idea has drawn scrutiny from some observers, who point to a similar effort decades ago that ended unsuccessfully and raised environmental concerns.

Growing regional tension

Local farmer and rancher Doug Weimar on Five Mile Road said he was against the sediment coming to the Wasco County Landfill because of the unsafe county road with blind corners and hairpin turns.

Together, the competing paths — shipping sediment to Eastern Oregon landfills or keeping it closer to Portland — are intensifying debate over who should bear the burden of one of the state’s largest environmental cleanups.

For communities in Wasco County, the issue has quickly shifted from a distant Portland cleanup to a local concern with potential impacts on transportation corridors, air quality and landfill use.

Organizers say the coming weeks — including the planned petition and May community meeting — will be critical in shaping how local leaders respond.

Read Aaron Girdham’s orginal CCCNews story on this project here.