Arkema Inc

This site is being cleaned up under Washington’s cleanup law, the Model Toxics Control Act (MTCA). For more information about the MTCA process, visit Ecology’s cleanup process webpage.

This is a formal cleanup site. That means the Department of Ecology is overseeing the cleanup of this site. The Port of Tacoma is the potentially liable party (PLP) who is conducting, managing, and paying for the cleanup.

Cleanup is being conducted through a legal agreement, Agreed Order No. DE 5668 (download 13.4MB), between Ecology and the Port of Tacoma. This agreement was signed on July 25, 2011.

Last updated: May 7, 2026

Cleanup of the entire site
As of 2025, the Port of Tacoma has wrapped up its study of the site. They are currently considering different cleanup options and working on developing their plans on how to clean up the site. Ecology is overseeing the Port as they conduct this cleanup work.

Once the Port finishes their cleanup plans, the following information will be made available for public comment:

• A remedial investigation: This is the Port’s findings from when they studied the site.
• A feasibility study: This is an overview of the cleanup options that the Port considered, how they considered them, and their reasoning for pursuing or not pursuing each option.
• A cleanup action plan: This plan explains how cleanup will be carried out for the whole site, why the chosen options were selected, and gives details on the cleanup schedule, standards, and requirements.

Interim (partial) cleanup of the site
Contaminated groundwater at the site is moving into the Hylebos Waterway. To address this, the Port of Tacoma is constructing a barrier wall, water-tight cap, and permanent asphalt cap to prevent the spread of groundwater while the port continues their efforts to clean up the entire site.

On April 14, 2026, Ecology signed an amendment to the agreed order (download 616 KB) that will require the Port of Tacoma to complete an interim (partial) cleanup. This partial cleanup will help address contaminated groundwater moving into the Hylebos waterway. The port will construct a barrier wall and ground-surface caps. The port is currently working on the design and permitting for this project.

The Arkema Inc. site was formerly a chemical plant, in the past called Atofina Chemicals, Elf Atochem, and Pennwalt. It is located at 2901 Taylor Way, on the shore of the Hylebos Waterway. The Port of Tacoma bought the property in 2007.

Past Use
The site was used as a chemical manufacturing facility from 1927 to 1997 and the majority of the manufacturing operations were performed in the former Central Manufacturing Area. The products that were manufactured in that area included chlorine, sodium hydroxide (caustic), sodium chlorate, hydrochloric acid, and sodium arsenite (Penite). Penite was manufactured between circa 1944 and the early 1970s. The remaining chlorine-based manufacturing facility operations ceased in 1997, at which time the manufacturing facilities were dismantled and removed from the site. The Port removed all remaining aboveground structures in 2008.

Present Use
The site is vacant. It is currently covered with vegetation, crushed rock, and some former building/tank foundations.

Future Use
The Port of Tacoma is preparing plans to put this portion of the site back into productive use. The Port's vision for the 2901 Taylor Way portion of the site is the Hylebos Barge Terminal Concept. This concept includes removing/addressing the numerous former infrastructure features at or below ground surface, installing an upland working surface that is suitable for Port Maritime and Industrial Use, and enabling marine dependent use for this property (e.g., upgrading the existing dock).

Wastes created during Penite production were dumped into pits. Arsenic leached from the pits into soil and groundwater beneath the site, and into nearby sediments.  Wastewater from the plant was released into two areas of the site.

One area, “Taylor Lake”, contained several ponds. Some ponds are highly caustic (high pH), while others have high levels of volatile organic compounds (VOCs) and other contaminants. A 1985 storage tank rupture contaminated soil with sodium chlorate and hexavalent chromium.

Since the 1980s, several cleanup activities have been completed at the site. These cleanup activities were completed according to the Clean Water Act, CERCLA, and MTCA. Approximately $16 million dollars have been spent through February 2021 to investigate and evaluate the site, and approximately $66 million dollars have been spent through February 2021 to clean up the site.

Completed remedial cleanup actions include:

• improving previous stormwater and wastewater systems,
• removing soil and sediment,
• installing soil and sediment caps,
• installing a Sheet Pile Wall (SPW),
• installing and operating a Pump & Treat (P&T) system for the main arsenic plume,
• conducting in-situ stabilization for the main arsenic plume,
• remediating volatile organic compound (VOC) source areas, and
• completing remediation for miscellaneous other releases.

Contaminants above state cleanup levels still remain at the site. These contaminants will be addressed through future MTCA cleanup actions.

From December 4, 2025, to February 20, 2026, Ecology held a public comment period on the site’s Interim Action Work Plan, Agreed Order Amendment, and SEPA determination. Ecology produced a fact sheet (download 1.2MB) that summarizes the documents. Ecology also accommodated a public comment period extension request. During this 79-day comment period, we received three comments.

More information about this public comment period, Ecology’s public outreach methods, and how Ecology has incorporated public feedback can be found in the 2026 Responsiveness Summary (download 1.5MB).

Ecology will keep the public informed as the cleanup progresses. To receive updates about this site:

• Sign up for updates by clicking the blue “Subscribe to this site” button at the top right corner of this page. Subscribers receive a weekly automated email whenever there’s an open comment period, a new document, or other cleanup news. You can read more about this feature on Ecology's blog.
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