Public comment period opens for Cosmo Specialty Fibers cleanup

By The Daily World • January 9, 2026 1:30 am
Washington Department of Ecology Storage tanks that house hazardous chemicals onsite at the Cosmo Specialty Fibers pulp mill are in poor condition, posing a risk for chemical spills that could harm human health and the environment. The tanks rest near the Chehalis River, which increases the likelihood of environmental damage if a spill happens.
Washington Department of Ecology Storage tanks that house hazardous chemicals onsite at the Cosmo Specialty Fibers pulp mill are in poor condition, posing a risk for chemical spills that could harm human health and the environment. The tanks rest near the Chehalis River, which increases the likelihood of environmental damage if a spill happens.

The state Department of Ecology invites the public to comment through 11:59 p.m., Feb. 19, on the proposed Interim Action Order for the cleanup of the Cosmo Specialty Fibers site.

A virtual public hearing to accept oral comments will be held on Feb. 11, at 6 p.m. on ZOOM (register at https://waecy-wa-gov.zoom.us/). Registration is required. After registering, you will receive a confirmation email containing information about joining the hearing.

When the comment period ends, Ecology will review the comments received and make a final decision on the documents.

The site is in Cosmopolis, and the main mill portion is located on the south bank of the Chehalis River. Weyerhaeuser constructed the pulp mill at the site in 1957. The mill made paper grade products until 1962, when Weyerhaeuser converted production to dissolving and specialty grade pulp. The mill made pulp by using magnesium sulfite to cook wood chips, then bleached the pulp using chlorine dioxide and other chemicals.

Weyerhaeuser operated the mill until September 2006, when production shut down. The company mothballed the facility the following year in preparation of selling the mill. In May 2011 the mill resumed operation as Cosmo Specialty Fibers (Cosmo), owned by Gores Group, LLC. In December 2022, Cosmo shut down its production and transferred ownership to Charlestown Investment.

The mill has remained shut down while the new owner pursues investors to re-start mill operations. However, chemicals used for the pulping process remain stored at the site. Staffing at the site has significantly reduced during that time and both power and water were shut off in the fall of 2024. As of the date of this document, there are about 800,000 gallons of chemical stored onsite as the current owner plans to use them during future startup.

Closed Cosmo pulp mill fined $2.3M

The owner of the closed Cosmo Specialty Fibers pulp mill was fined $2.3 million last summer for lack of action on leaking hazardous chemicals at the site in Cosmopolis.

Storage tanks, treatment systems and environmental equipment at the Cosmo Specialty Fibers pulp mill continue to steadily deteriorate, leading to dangerous conditions and mounting threats to nearby neighborhoods, the Chehalis River and Grays Harbor.

While the pulp mill has not operated since 2022, large quantities of chemicals and dangerous waste remain stored at the site. Even while closed, state and federal laws require the mill’s owner to properly maintain the facility, manage the hazardous materials and follow environmental regulations.

In response to dangerous conditions and the mill owner’s lack of action, the Washington Department of While the facility has been dormant, Cosmo has failed to meet other regulatory requirements. This includes participating in the state’s Cap-and-Invest program, which reduces greenhouse gas emissions across the state’s economy. Historically, Cosmo was one of the largest sources of carbon pollution in the state, which meant that it is covered under the emissions reduction program. However, Cosmo was the only company that did not comply with the program in 2024.

How the site became contaminated

Constructed in 1957, the facility predates environmental laws and regulations, including the 1976 Resource Conservation and Recovery Act (RCRA) and the 1989 Model Toxics Control Act (MTCA). Over the years, there have been documented releases, including the following:

• Liquid chlorine leak from a chlorine car on Oct. 27, 1979.

• Release of magnesium oxide dust from a recovery bypass valve on Dec. 1, 1979 for a duration of five hours.

• Spill of about 1,000 gallons of red liquor to the stormwater system on Feb. 6, 1980. Red liquor is a mixture of spent pulping chemicals and organics specific to the sulfite pulping process.

• Spill of sodium hydroxide from a railcar off-loading in February 1995, resulting in groundwater exceeding the pH 12.0.

• Spill of acidified water to the ponds on Jan. 6, 1998, resulting in pH measurements as low as 1.0 in the adjacent ditches.

• About 16 leaks in the wastewater pipe over the last 10 years, with the most recent leak discovered on Sept. 12, 2023 at the residential area. The pipe is made of wood stave and runs about 2.5 from the mill through the town of Aberdeen and Cosmopolis.

In addition to documented spills, the November 2017 Sediment Study found elevated levels of dioxin and furans in the vicinity of the mill’s outfalls.

You can submit online comments at https://swm.ecology.commentinput.com/?id=CSti4GcVk or by mail to:

Ha Tran

Department of Ecology

Industrial Section

P.O. Box 47600

Olympia, WA 98504-7600

For more information on this cleanup site see Ecology’s cleanup webpage.