Washington's Department of Ecology has issued the disposal decision the Onni 606 cleanup schedule anticipated. The August 13 contained-in determination applies to a specific 21,250 tons of PCE-contaminated soil expected during excavation at 606 and 620 106th Avenue NE, within the lateral and vertical limits mapped in the letter. Ecology's public cleanup file was checked through August 23.
Ecology found that the identified soil contains F002-listed dangerous-waste constituents—tetrachloroethene, or PCE—at concentrations that do not warrant management as dangerous waste, provided every condition in the letter is followed. The decision applies only to those 21,250 tons. It does not cover contaminated water, soil-and-fluid mixtures, material outside the mapped limits or soil excavated from other areas of the property.
The new number needs its date and scope. The project's 2021 cleanup plan estimated roughly 17,500 tons of PCE-affected soil, based on about 2,500 cubic yards of shallow material and 10,000 cubic yards of deeper material. The August 2026 determination instead defines the specific quantity covered by the current contained-in disposal pathway after additional characterization. The two figures should not be merged, and neither is the total quantity of ordinary earth removed for the five-level garage.
The handling conditions are specific. Any truck bed or roll-off bin carrying the CID soil must be plastic-lined and covered, with standing water removed. The material may not be mixed with other soil. A properly trained transporter must take it directly to a Washington-permitted solid-waste landfill or transfer station; an out-of-state destination would require written approval in advance from the receiving state's hazardous-waste program and landfill. The letter does not publicly name a receiving facility.
The paperwork will follow every load. Onni or environmental consultant TRC must give Ecology at least five days' notice before removal, allowing the agency to elect to observe. Itemized tables are due monthly beginning August 31, 2026 and ending April 30, 2027, with each shipment's departure and receipt dates, weight, cumulative tonnage, approximate percentage removed, and the landfill's name and location. Disposal under the determination must finish by April 30; signed landfill receipts or a disposal certificate are due May 31, 2027.
This is not a declaration that the site is clean. Ecology states that the letter is neither a No Further Action letter nor written approval of a cleanup action plan; cleanup levels, the remedy and any final opinion remain separate Model Toxics Control Act decisions. Ecology's December 15, 2021 'No Further Action Likely' opinion is itself prospective: it says further remedial action will likely not be needed if the proposed independent cleanup is completed, and a completion report and new opinion request are still required afterward.
That 2021 opinion also supplies the careful account of where the plume came from. Ecology says the contamination on the Onni property is believed to originate solely from the upgradient Thinker Toys and Bellevue Corner Unocal sites across NE 8th Street, and that no current or historical operation suggests PCE use on the Onni block. It does not allocate how much each northern site contributed, resolve liability to the state or determine that Onni's independent cleanup is equivalent to an Ecology-conducted or Ecology-supervised action.
Finally, the August decision should not be applied retroactively to earlier camera or permit observations. Bellevue's July 28 early-grading inspection recorded soil being exported and required a mechanical street sweeper, but did not identify that material as contaminated or state its destination. With no public landfill named as of August 23, the defensible update is narrow: Ecology has now established the controlled disposal and reporting rules for the 21,250-ton CID soil stream; the public record does not yet show which observed loads, if any, were part of it.
Sources
Independent and unaffiliated with Onni Group. Written from the public City of Bellevue record; corrections via the contact form.