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Underground Storage Tank Rule-making

Adopted Rule

On August 8, 2012, the Department of Ecology (Ecology) adopted changes to Chapter 173-360 WAC, Underground Storage Tank (UST) Regulations. The changes will be published in the Washington State Register on September 5, 2012, and become effective on October 1, 2012.

To view the Rule Adoption Notice in Korean, see 개정 법규 알림

Text of Rule Changes

To view the text of the adopted changes to Chapter 173-360 WAC, click here.

Summary of Rule Changes

The adopted changes to Chapter 173-360 WAC:
  • Authorize Ecology to stop regulated substances from being delivered to UST systems that do not comply with regulatory requirements.
  • Establish an operator training program for individuals who operate and maintain UST systems.  Current operators must be trained by December 31, 2012.
  • Require emergency response signage at all UST facilities.
  • Require secondary containment and interstitial monitoring of tanks and pipes installed or replaced after October 1, 2012.
  • Require containment under dispenser systems if the dispenser, dispenser system, or underground piping connected to the dispenser system is installed or replaced after October 1, 2012.

Persons Affected by the Rule Changes

The rule changes affect:

  • Persons who own or operate UST systems.
  • Persons who provide services to owners and operators.
  • Persons who deliver product to, or collect waste oil from, UST systems.
  • Persons who train operators of UST systems.

Response to Comments on Rule Proposal

Ecology’s response to comments received during the public comment period is now available.  The response is contained within the Concise Explanatory Statement.
The purpose of the Concise Explanatory Statement is to:

  • Provide reasons for adopting the rule.
  • Describe any differences between the proposed and adopted rule.
  • Provide Ecology’s response to public comments on the proposed rule.

This documentation is required by the Administrative Procedure Act (RCW 34.05.325).  

Supporting Documentation

The following economic and environmental analyses were performed on the adopted rule changes:  

Rule Implementation

Ecology has developed an Implementation Plan for the adopted rule changes.  The purpose of this plan is to inform those who must comply with amended rule how Ecology intends to: 

  • Implement and enforce the amended rule.
  • Inform and educate persons affected by the amended rule.
  • Promote and assist voluntary compliance with the amended rule.
  • Evaluate compliance with the amended rule.
  • Train and inform Ecology staff about the amended rule.

This information is required by the Administrative Procedure Act (RCW 34.05.328).

More Information


Rule-Making Order (CR103)

Rule Adoption Notice

News Release

Contact Info

UST Coordinator

Ecology Rule Page

UST Rule Making

Focus Sheets:

"New" icon Focus on Emergency Signage Required for UST Sites

Focus on Delivery Prohibition or “Red Tagging”

Focus on the new UST Secondary Containment Requirements