Cowlitz County health officer says major industrial release was rapidly diluted; drinking water tests show no detections

Dr. Steve Greger, Cowlitz County health officer, told the Board of Health that about 600,000 gallons of a substance the meeting referred to as “white liquor” was released in a sudden tank failure and that 11 people died in the incident.

Greger said county public health’s role was primarily monitoring and communications while state and federal agencies led cleanup and remediation. He described a fast, multi‑agency response that focused on preventing the contaminated water from reaching the Columbia River and on testing air and drinking water for contamination.

“The force of that spill ... was pretty great,” Greger said, and agencies measured pH and other markers as they worked to move contaminated water out of on‑site dikes and ditches. He described the response to flushing those containment features with river and hydrant water and then monitoring the outfall to the Columbia River to ensure pH did not reach unsafe levels.

Greger explained that the substance is highly alkaline and that, as it interacted with air, it produced hydrogen sulfide — the rotten‑egg smell residents reported. He noted that odor can be detected by the nose at levels below instrument detection, and that air monitoring did not show hydrogen sulfide at levels that would be considered harmful.

“About 600,000 gallons of a substance called white liquor ... was released,” Greger said. He said the county did not lead the cleanup but worked closely with the EPA, the state Department of Ecology, the dyking district, city public works and tribal partners to protect the river and public health.

A board member who sits on the clean‑air board said local monitoring showed no particulate matter and added, “If you can smell it, it’s probably not going to hurt you,” a point echoed in the meeting as officials stressed the difference between odor perception and measured toxic exposures.

Greger also said initial drinking‑water monitoring in the city did not detect contamination and that rapid flushing of dikes and ditches likely limited the duration that contaminated water sat in those systems. He noted the response had environmental consequences — including fish kills in the dikes and ditches — but said state and federal partners judged the dilution and monitoring plan sufficient to protect the Columbia River.

Greger described the chemical’s pH as very high — near the alkali end of the scale — which is what makes the substance corrosive and why quick mitigation was important. He told the board that precise estimates of long‑term soil or groundwater movement would require additional geologic data and that the number of people transported to hospitals varied because some self‑transported, so the exact injury count beyond the 11 fatalities was not available in the meeting record.

The board and Greger thanked first responders and hospital staff for their work and noted the emotional toll on survivors and families. No formal actions or new directives were recorded during the discussion; the board received the update and proceeded to other agenda items.

The board adjourned at 10:35 a.m.