605 Alexander Ave, Tacoma, WA 98421-4209


Last Updated 4/27/2017

Public Comment Period Extended
We have extended the comment period on the feasibility study and related documents by an additional 60 days following a request from the Puyallup Tribe. This is the second extension to the comment period. Earlier this year, we doubled the length of the comment period to 90 days after community groups asked for more time to review and respond to the study.

Submit comments to Kerry Graber by email or mail by 5 p.m. on Monday, June 26.

Kerry Graber
Site Manager
PO Box 47775
Olympia, WA 98504-7775
Email: kerry.graber@ecy.wa.gov

The draft documents available for review and comment include:

Draft Agreed Order
The Agreed Order is a legal document that requires Occidental to:

  • Perform pumping tests to assist in evaluating the reliability and performance of hydraulic containment systems.
  • Develop and implement a monitoring program in advance of the remedy selection.
  • Submit a draft Cleanup Action Plan (dCAP). 

Draft Feasibility Study
Occidental submitted a draft Feasibility Study (FS) to Ecology. The FS develops remedial action goals, identifies remedies for contamination, and evaluates cost estimates for cleanup alternatives. All of the proposed alternatives will include institutional controls, along with groundwater and soil vapor monitoring. We’ve provided an overview of the three cleanup alternative categories below. 
1. Containment Alternatives

  • An asphalt cover over the Site.
  • A sheet pile vertical barrier wall adjacent to the Hylebos Waterway.
  • Variable amounts of groundwater extraction and treatment.

2. Volatile Organic Compounds (VOCs) Mass Removal or Reduction Alternatives

  • Extracting and treating groundwater.
  • Excavating shallow contaminated soils.
  • Treating soil contamination using heat.
  • Extracting soil vapor.
  • Treating groundwater using a chemical oxidant.
  • Treating groundwater using bioremediation.

3. pH Reduction/Enhanced Containment
The pH reduction/enhanced containment alternatives are designed to address high pH in groundwater and soil. These alternatives include in-situ treatment or containment of soil and groundwater. These alternatives would need to be combined with containment alternatives.
Vapor Intrusion Memo and Reports
Vapor intrusion (VI) occurs when gases from chemicals in the soil and groundwater enter buildings. VI can cause potentially unhealthy levels of hazardous substances in indoor air. Ecology reviewed Occidental's site vapor intrusion study and found a significant vapor footprint below the former Occidental plant production area. There is also a significant vapor footprint from the solvent production settling ponds. 
Corrective Action Permit
Corrective Action permits are administrative documents that allow cleanup work to begin at facilities that have treated, disposed of, or stored dangerous waste.
Porewater Sampling Results
In the summer of 2016, Occidental sampled porewater – the water in the small spaces between soil. Samples were taken in the Hylebos Waterway and Commencement Bay to see if any contamination from the groundwater plume was entering the water. The results show that there is one area where contamination may enter the Hylebos. However, the concentration was low enough to not pose a direct threat to the public or wildlife.

Public Hearing
Thanks to everyone who attended our open house and public hearing on March 8. We appreciate the time you took to engage with us about this complicated site. For those who missed it, check out our presentation from the hearing.

Remediation options outlined in the draft Feasibility Study report.
Please click on the photo for a larger view


Draft Agreed Order
Agreed Order

    Exhibit A: Facility Figure
    Exhibit B: Administrative Order on Consent (AOC), AOC Amendment, AOC Memorandum of Understanding
    Exhibit C: Progress Report
    Exhibit D: Schedule
    Exhibit E: Data Quality Objectives (DQOs)

Feasibility Study
Feasibility Study Report
    Occidental Letter to Agencies on draft Feasibility Comments 12/18/2016
    Occidental Letter to Agencies on draft Feasibility Study Comments 1/17/2017

Vapor Intrusion Reports and Memos
    May 2014 Vapor Investigation
        Appendix A: Survey Questionnaires and Tenant Provided MSD Sheets
Appendix B: Cross-sectional views illustrating building specific concentrations in air, soil and groundwater.
        Appendix C: Data Quality Assessment and Validation
        Appendix D: Laboratory Analytical Reports (This is a very large file. If you are interested in accessing this document, contact Bridgette Valdez-Kogle).
    March 2016 Vapor Intrusion Report
        Appendix A: Survey Questionnaires and Tenant Provided MSD Sheets
        Appendix B: Cross-sectional views illustrating building specific concentrations in air, soil and groundwater.
        Appendix C: Data Quality Assessment and Validation
        Appendix D: Laboratory Analytical Reports (This is a very large file. If you are interested in accessing this document, contact Bridgette Valdez-Kogle).

    Vapor Intrusion Mitigation Report
    Ecology's Vapor Intrusion Memo

Corrective Action Permit
Corrective Action Permit

Porewater Data Report
Porewater Data Report
    Appendix D: Field Data Reports. (This is a very large file. If you are interested in accessing this appendix, contact Bridgette Valdez-Kogle.)
    Appendix E: Data Validation
    Appendix F: Laboratory Reports. (This is a very large file. If you are interested in accessing this appendix, contact Bridgette Valdez-Kogle.)

University of Washington Study
Examination of Silica Precipitation, Gelation, and Hydraulic Fouling at the OCC Site

Please click on the photo for a larger view


This former manufacturer of chlorine, bleach, and other chemicals for the paper industry is no longer operating. The above-ground features of the manufacturing plant are removed, and little remains of the industrial equipment except for the groundwater treatment plant. Other activities on-site includ ship-building and dismantling and chemical manufacturing.

Primary products produced on-site include:

  • Chlorine and chlorinated solvents (TCE and PCE)
  • Caustic soda
  • Ammonia
  • Calcium chloride
  • Muriatic acid.

Site History
Prior to 1920: Undeveloped tidal mudflats.

1920-1936: Area filled with dredge material as part of an upland expansion project.

1929-2002: Occidental Chemical Corporation (Occidental) and its predecessors make chemicals. Other owners and operators during this period include the US Navy, US Defense Plant Corporation, Todd Shipyards, and Pioneer Americas.

1988-2004: EPA conducted a RCRA Facility Investigation and later activities to investigate the site.

2005: Ecology and the EPA issued a Statement of Work for the Administrative Order on Consent. These documents guide site investigation activities.

2006-2008: Occidental demolished former manufacturing facilities.

2005-Present: Occidental conducted numerous investigations to assess impacts to on-Site and off-Site soil, groundwater, sediment, and soil vapor.

Please click on the photo for a larger view


There are hazardous substances in the groundwater, soil, and sediment throughout the site. Contamination is from historical operations and waste disposal practices. Occidental and past owners and operators of the facility contributed to the contamination.
The primary contaminants include:    

  • Chlorinated volatile organic compounds (CVOCs)
  • Sodium hydroxide
  • Salt (sodium chloride)
  • Metals 
  • By-products of chlorinated solvent production
  • Poly-chlorinated Biphenyls (PCB)
  • Dioxins/furans
Soil contamination
CVOCs, hexachlorobenzene (HCB), PCBs, and metals are present in Site soil. CVOC and HCB impacts are found on Site and beneath the Hylebos Waterway. There are PCBs and metals impacts primarily along the embankment.
Groundwater contamination
The groundwater is contaminated with CVOCs, dense non-aqueous phase liquid (DNAPL) consisting of concentrated PCE and TCE, and elevated pH.
The CVOC plume extends to the north from below the Site to the northern end of the peninsula and under Commencement Bay, and to the east below the Hylebos Waterway. The plume gets deeper as it extends away from the Site. The depth of the CVOC plume extends to 160 ft below sea level.
The pH plume is mostly below the Site, but does extend to the north under the peninsula and to the west under the Hylebos Waterway. The depth of the pH plume extends to 100 ft below sea level. Other contaminants including HCB, PCBs, and metals were found in groundwater, but in localized areas.

Proximity of the facility to the Hylebos Waterway poses unique challenges for measuring the contamination. More than one study was conducted over the years to attempt to understand the hydrogeology. Efforts over the past two years have focused on filling data gaps and supplementing remedial investigation data. 


Occidental submitted a risk assessment that has not been formally approved by Ecology. The risk assessment predicts possible affects to the environment or people and is referred to in the draft Remedial Investigation (RI). Ecology will work with a contractor, Ridolfi Environmental, to evaluate the quality of the risk assessment and exposure pathway information as the cleanup process moves forward.
Chemicals could enter the body three ways: breathing dust, touching contaminated soil, or swallowing contaminated soil or groundwater. Based on the current risk assessment, there is no direct risk to the public of exposure to these chemicals. Only authorized persons may enter the site area. Cleanup workers at the site follow a site safety plan developed and overseen by Occidental and its contractors. The plan limits the workers’ direct contact with contaminated soil, groundwater, and sediment, or breathing in indoor air at the site and at the neighboring Port of Tacoma property. Air samples taken in the buildings in and near the site showed CVOC levels below industrial standards. This means, in an industrial setting, potential exposure is below a level that would pose a risk to adult humans.
People that consume resident fish and shellfish from the Hylebos creek may have an indirect risk of exposure. Ecology is addressing this indirect risk and will keep the public updated. Find more information about healthy fish consumption at Washington Department of Health’s website.

Shellfish harvesting is closed in Commencement Bay due to pollution. Find out more by visiting Tacoma-Pierce County Health Department’s Safe Shellfish program's website.
Contamination does not affect public drinking water. If you have a private well nearby, please contact Tacoma-Pierce County Health Department at 253-798-6470.

Please click on the photo for a larger view


The EPA oversees the mouth of the Hylebos, Commencement Bay, and sediments areas. Ecology’s Hazardous Waste and Toxics Reduction Program leads the investigation and cleanup of the uplands, including the groundwater, surface water, and soil. The two agencies work together on the major milestones of the cleanup process.

A Remedial Investigation (RI) is an in-depth study to:

  • Determine site features such as groundwater flow, sediment type, and other factors.
  • Define the type and extent of contamination.
  • Assess potential effects on human health and the environment.
  • Establish cleanup criteria.
Ecology held a public comment period for the draft RI from Oct. 23, 2015-Feb. 2, 2016. We received thoughtful questions and comments from the public. The Occidental Remedial Investigation Responsiveness Summary is now available. 
Ecology approved the RI Report with specific wording changes and the removal of references not previously approved by Ecology or EPA. We kept our edits and deletions clear using red strike outs and end notes in the Final RI Report.

While questions remain about certain aspects of the contamination, Ecology believes that sufficient information was collected to proceed to the problem-solving phase of the Feasibility Study (FS).

A Feasibility Study (FS):

  • Establishes cleanup criteria.
  • Evaluates cleanup alternatives.
  • Evaluates cost estimates of cleanup alternatives.

The draft Feasibility Study is now available for public comment and review.

A Cleanup Action Plan CAP:
  • Describes the selected cleanup methods.
  • States cleanup standards and other requirements.
The CAP is based on information and technical analyses from the RI/FS and public comments and community concerns. A draft of the CAP will be available for public review and comment before it becomes final. The draft CAP is expected after the FS is approved.



Map showing site location as Pierce County, WA SITE INFORMATION


View Electronic Documents

Site Summary Report

Facility Site ID: # 1212

Cleanup Site ID: 4326

Tacoma, Pierce County

Status: Cleanup Started   Get definitions of Status terminology

Comment Period:
JANUARY 27, 2017 - JUNE 26, 2017

Kerry Graber
Site Manager
(360) 407-0241

Bridgette Valdez-Kogle
Public Involvement Coordinator
(360) 407-7616

Document Repositories:

Southwest Regional Office
300 Desmond Dr SE
Lacey, 98503-1274

Citizens for a Healthy Bay
535 Dock St., Suite 213
Tacoma, 98402

Kobetich Library
212 Browns Point Blvd. NE
Tacoma, 98422