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Toxics Cleanup Program

Chapter 173-360 WAC

Underground Storage Tank Regulations


The Department of Ecology (Ecology) plans to amend Chapter 173-360 WAC, Underground Storage Tank (UST) Regulations.  The regulations are intended to prevent the release of petroleum or other hazardous substances from UST systems, and ensure that any release is detected and cleaned up.    

View the Rule Announcement Notice in Korean.


Washington State currently has a federally-approved UST compliance program.  This means that state law, not federal law, applies to regulated UST systems in the State (except for those in Indian country). 

Under state law, Ecology currently regulates more than 9,000 systems at more than 3,300 facilities, including gas stations, industries, commercial properties, and governmental entities.  Ecology works to ensure that UST systems are installed, managed, and monitored in a manner that prevents releases into the environment.  To do so, Ecology conducts compliance inspections at about 1,200 facilities each year, and provides technical assistance to owners and operators.  Learn more about the program.

In October 2015, the U.S. Environmental Protection Agency (EPA) adopted changes to the rules governing the federal UST program (40 CFR Part 280) and state program approval (40 CFR Part 281).  These are the first major changes to the federal rules since 1988.  The changes implement the requirements in the UST Compliance Act of 2005, add new operation and maintenance requirements for UST systems, and establish requirements for certain types of UST systems deferred in 1988.  States with federally-approved programs must incorporate the changes by October 2018 to maintain program approval.  Learn more about the changes.

Subject and Scope of Rulemaking

Ecology plans to amend Chapter 173-360 WAC, Underground Storage Tank (UST) Regulations.  As part the rulemaking, Ecology plans to:

  1. Incorporate federal rule changes needed to maintain state program approval, as specified in 40 CFR Parts 280 and 281 and adopted in June 2015.
  2. Incorporate changes to the state’s UST program specified in the authorizing state statute, Chapter 90.76 RCW.
  3. Make other selective changes to the requirements governing the state’s UST program (such as updating UST service provider requirements).
  4. Streamline rule requirements, improve rule clarity, and improve consistency within the rule and with other state and federal laws and rules.

Reasons for Rulemaking

Ecology is conducting the rulemaking to:

  1. Maintain federal approval of the state’s UST program, as required by the authorizing state statute, Chapter 90.76 RCW.
  2. Implement changes to state’s UST program specified in the authorizing state statute, Chapter 90.76 RCW.
  3. Reduce the number and severity of releases of petroleum and other hazardous substances from UST systems, which pose a serious threat to human health and the environment, including drinking water.
  4. Make the rule easier to use and understand by the regulated community.

Persons Impacted

The rulemaking may impact persons who:

  • Own or operate UST systems.
  • Provide services to owners and operators.
  • Deliver product to, or collect waste oil from, UST systems.
  • Provide pollution liability insurance for UST systems.
  • Conduct training for operators of UST systems.

Stay Informed

You can stay informed about the rulemaking and public involvement opportunities by:

  1. Visiting our web page
  2. Signing up to receive email notices
  3. Contacting the UST Coordinator:

    Kristopher Grinnell
    Department of Ecology
    P.O. Box 47600
    Olympia, WA 98504-7600
    Phone: 360-407-7382
    Fax: 360-407-7154

Get Involved

You can get involved in the rulemaking by:

  1. Participating in Rule Development

    During the development of the rule proposal, Ecology plans to consult with:

    • The U.S. Environmental Protection Agency (EPA) to ensure the rule changes meet the minimum federal requirements for state program approval.
    • Other state agencies that implement or may be affected by the rule changes, including the Department of Revenue (about licensing), the Pollution Liability Insurance Agency (about financial responsibility), and the State Building Code Council (coordination with state codes).
    • Representatives of the regulated community and other interested persons to help determine how to incorporate required changes and whether any other changes should be made to the existing rule.

    Ecology will also extend an offer for government-to-government consultation with tribal governments during each phase of rule development.  In general, UST systems in Indian country are regulated under federal law, not state law.

    As part of the consultations, Ecology may share preliminary drafts of the rule.

  2. Commenting on the Rule Proposal

    Ecology will submit the proposal for review and comment and hold at least one public hearing on the proposal.




Kristopher Grinnell


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