On November 22, 2019, the Washington Department of Ecology (Ecology) finalized changes to the state's toxic air pollutant (TAP) rule in Washington Administrative Code (WAC) 173-460. The rule took effect on December 23, 2019. The changes to the TAP program include:

  • Updates to the list of TAPs, including the addition of 45 new TAPs and removal of 8 former TAPs
  • Changes to TAP thresholds (de minimis thresholds, Small Quantity Emission Rates, and Acceptable Source Impact Levels) for various pollutants based on more current toxicity information. These changes relaxed the thresholds for some TAPs and tightened thresholds for others.

Due to the way air quality regulations are implemented in Washington, implementation strategies for the new rule vary among local agencies. Trinity contacted the various local agencies to gather information on their plans; their responses are summarized below.

Ecology: For sources regulated directly by Ecology Industrial Section or in counties covered by an Ecology regional office, the new TAP rule went into effect immediately upon its promulgation in December. Notice of Construction (NOC) permit applications currently in process will need to address requirements under the new TAP rule before a permit can be issued and will not be grandfathered under the old TAP rule based on the application date. As a result, applicants may need to submit an addendum to their NOC application to address the new rule.

Olympic Region Clean Air Agency (ORCAA): ORCAA indicated that it adopted the new rule with no changes, and the new rule went into effect in their jurisdiction immediately upon its promulgation in December. In line with Ecology, ORCAA requires that NOC applications in process address the requirements under the new TAP rule before a permit can be issued.

Northwest Clean Air Agency (NWCAA): The new TAP rule will not apply to sources in NWCAA's jurisdiction until NWCAA conducts their own rulemaking to adopt the rule. That rulemaking process is anticipated to take 6-12 months. NWCAA has not yet decided how they will handle pending permit applications when the new rule goes into effect, but is likely to follow the same approach as Ecology, requiring pending applications to be updated to address the new rule if the rule becomes effective prior to permit issuance.

Puget Sound Clean Air Agency (PSCAA): The new TAP rule will not apply to sources in PSCAA's jurisdiction until PSCAA updates the list of WAC provisions that are incorporated by reference in PSCAA Regulation I, Section 6.01. PSCAA intends to update those references sometime in Spring 2020. Like the other agencies, PSCAA will apply the new standard based on the day permits are issued, not the application date. Consistent with its current practice, PSCAA will not adopt the de minimis emission rates in the rule.

Southwest Clean Air Agency (SWCAA): Consistent with its decision following prior rule revisions in 2009, SWCAA will not adopt the new TAP rule. The older 1998 TAP rule will remain in effect in SWCAA's jurisdiction. SWCAA is considering writing its own rule later in 2020. SWCAA expects that the new rule will be based on a larger list of pollutants and will use a wider set of reference sources to establish health thresholds.

For more information on the new TAP rule, you can contact Aaron Day and find additional details in Trinity's previous articles: