Facility Site ID: 1220
Cleanup Site ID: 3405

Cleanup Status

A graphic showing where the Arkema Inc. is located in the MTCA cleanup process.
A graphic showing where the Arkema Inc. is located in the MTCA cleanup process.

Arkema Inc. is being cleaned up through Washington’s cleanup law, the Models Toxic Control Act. For more information about MTCA’s cleanup process, please visit Ecology’s cleanup process website.

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.

Stay informed:

  • Subscribe for site updates by clicking the blue “Subscribe to this site” button at the top of this page. Subscribers will receive automated email updates for open comment periods, new document uploads, or changes to the cleanup status. Visit Ecology’s blog to learn more about this feature.
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Description

A July 1956 aerial photo of a chemical manufacturing plant (Pennwalt) that operated at the site. Credit: Northwest Room at The Tacoma Public Library, (Richards Studio A100512-2)
A July 1956 aerial photo of a chemical manufacturing plant (Pennwalt) that operated at the site. Credit: Northwest Room at The Tacoma Public Library, (Richards Studio A100512-2)

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).

Contamination

Arkema Inc.'s main arsenic groundwater plume, sources of contamination, and proposed barrier wall.
Arkema Inc.'s main arsenic groundwater plume, sources of contamination, and proposed barrier wall.

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.

History Of Cleanup Efforts

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.

Site use restrictions called institutional controls are in effect

Institutional controls can be fences, signs, or restrictions on how the property is used. For instance, an institutional control may prohibit installing drinking water wells or disturbing a protective cap that isolates contamination. These restrictions keep the contamination contained and keep people from being exposed to the contamination. The controls are usually listed in environmental covenants recorded with the county.

Periodic reviews are required when institutional controls are required at a site. Ecology conducts reviews to make sure the controls remain effective and the cleanup still protects human health and the environment. We conduct periodic reviews about every five years.

Environmental Covenant

County Recording #: 9302020332
County Recording Date: 1/18/1993

Restrictions/Requirements

  • Ongoing Maintenance of Remedy

Restricted Media

  • Soil
Legal 5
Document Title Document Date Document Type
Arkema Inc Draft Agreed Order Amendment 10/31/2025 Agreed Order Amendment
Arkema Inc. Agreed Order 2011 7/25/2011 Agreed Order
Arkema Inc Restrictive Covenant January 1993 1/18/1993 Environmental Covenant; Alternative Mechanism
ELF Atochem Consent Decree 7/23/1992 Consent Decree
Arkema Inc Consent Decree 6/24/1987 Consent Decree
Outreach Information 2
Document Title Document Date Document Type
Arkema Inc. Public Participation Plan 6/3/2011 Public Participation Plan
Arkema Inc. Agreed Order Fact Sheet 6/1/2011 Fact Sheet\Public Notices
State Environmental Policy Act 2
Document Title Document Date Document Type
Arkema Inc SEPA DNS (Wypenn Interim Action) 10/1/2013 SEPA Documents
Arkema Wypenn Interim Action SEPA Checklist 9/3/2013 SEPA Documents
Technical Reports 21
Document Title Document Date Document Type
Arkema Inc 2025 Draft Interim Action Work Plan Appendices A-E and J-K 8/13/2025 Interim Action Plans and Reports
Arkema Inc 2025 Draft Interim Action Work Plan Appendix G 8/13/2025 Interim Action Plans and Reports
Arkema Inc 2025 Draft Interim Action Work Plan Appendix H 8/13/2025 Interim Action Plans and Reports
Arkema Inc 2025 Draft Interim Action Work Plan Appendix F 8/13/2025 Interim Action Plans and Reports
Arkema Inc 2025 Draft Interim Action Work Plan no Appendices 8/13/2025 Interim Action Plans and Reports
3405 Arkema 20250728 7/28/2025 Site Hazard Assessment and Ranking Process Report
North Boundary Area Focused Feasibility Study Report 6/28/2023 Feasibility Study
Expanded RTC Data Gaps Investigation Work Plan 6/28/2023 Remedial Investigation Work Plan
Arkema Inc. - Ecology Review Feasibility Study 8/25/2021 Site Specific Administrative Document - Other (Administrative Correspondence)
Arkema Inc - Feasibility Study 4/1/2021 Feasibility Study
Fifth Five-Year Review Report for Commencement Bay Nearshore/Tideflats Superfund Site 5/1/2020 Periodic Review (5 Year)
Feasibility Study Data Gap Investigation Report 7/25/2019 Remedial Investigation Report
Appendix A to D to Data Gap Study 7/25/2019 Remedial Investigation Report
Appendix E to the Data Gap Study Report 7/25/2019 Remedial Investigation Report
Appendix F Through J to the Data Gap Study 7/25/2019 Remedial Investigation Report
Cost Allocation Report - North Boundary Area 7/21/2017 Site Specific Technical Document - Other
Cost Allocation Report _NBA Appendix D Historical Photographs 7/21/2017 Site Specific Technical Document - Other
Arkema- Comments on feasability Study 9/12/2016 Feasibility Study
Wypenn Interim Action Report 1/14/2015 Interim Action Plans and Reports
Remedial Action Area - Former Arkema Wypenn Property 5/6/2014 Remedial Action Report
Final Remedial Investigation Report 9/17/2013 Remedial Investigation Report
There may be more documents related to this site. To obtain documents not available electronically, you will need to make a public records request.

Places to see print documents

  • Southwest Regional Office
    300 Desmond Dr SE
    Lacey, 98503-1274
    Please schedule an appointment to view print documents at this location.

Contaminants 5

Contaminant Type
Soil
Groundwater
Surface Water
Air
Sediment
Bedrock
Halogenated Organics - Halogenated Organics C C R RA
Metals - Metals Priority Pollutants C C R RA
Reactive Wastes - Corrosive Wastes C C R RA
Other Contaminant - Conventional Contaminants, Inorganic C C R RA
Metals - Arsenic C C
S
Suspected
C
Confirmed Above Cleanup Levels
B
Below Cleanup Levels
RA
Remediated-Above
RB
Remediated-Below
R
Remediated
This contaminant list was based on our best information at the time it was entered. It may not reflect current conditions at the site.