Settlement Agreement: A settlement between the City of Bellingham (the City) and the Northwest Clean Air Agency (NWCAA) regarding the City’s Post Point Wastewater Treatment Plant (Post Point) requires the installation of additional air pollution controls and the operation of carbon monoxide (CO) continuous emission monitors for both sludge incinerators to meet emission limits that apply to new incinerators (40 CFR 60 Subpart LLLL).
How long will it take to install additional air pollution controls?
Continuous air quality improvements are expected during the next 5 years. The incinerators already operate with afterburners, which burn off air pollution. Installing additional controls to further reduce air pollution is complicated and time consuming, especially since the incinerators must continue operating throughout the project. Post Point presented, and NWCAA reviewed, a detailed timeline created by their consultants. NWCAA found the timeline to be reasonable and relied on it in the settlement agreement.
What about interim controls?
The settlement requires Post Point to operate the existing afterburners at or above minimum temperatures which have been shown effective in meeting the limits in 40 CFR 62 Subpart LLL. In addition, the CO continuous monitors will provide operators with tools to optimize incinerator operation.
Why not require something else, like off-site sludge disposal, instead of incineration?
Decisions regarding how to dispose of sludge from Post Point rest with the City rather than NWCAA. NWCAA regulates air emissions, not waste disposal methods, and NWCAA acts on the project the City puts in front of us for review. The City has indicated that it plans to continue using incineration for sludge disposal, as it has since the 1970s. NWCAA has worked with the City to establish a process to assure that future use of the incinerators will meet air regulatory requirements.
Is there an air quality concern?
No. The incinerators are tested annually and this testing has demonstrated that the City’s incinerators comply with health-based limits in EPA rules (40 CFR 62 Subpart LLL) that apply to existing incinerators.
If there is no air quality concern, why does 40 CFR 60 Subpart LLLL have stricter limits than 40 CFR 62 Subpart LLL?
EPA rules recognize that as technology evolves, newer equipment will be capable of operating with less air pollution. Hence, 40 CFR 60 Subpart LLLL, which applies to “new” incinerators, has stricter air pollution limits than 40 CFR 62 Subpart LLL, which applies to “existing” incinerators. The limits in 40 CFR 60 Subpart LLLL are technology-based standards.
EPA’s rules recognized that facilities may try to extend the useful life of existing equipment through a series of projects. This can preclude making investments in new, less-polluting equipment. The rules address this by requiring existing equipment to meet the stricter limits that apply to “new” equipment when projects exceed a certain cost threshold.
NWCAA and Post Point discussed the investments made to continue operating the Post Point incinerators. We were unable to agree on whether sufficient investments have already been made to make the incinerators subject to 40 CFR 60 Subpart LLLL. However, we did agree that it was in the public’s interest to put aside the rule-applicability discussion and focus instead on installing air pollution controls expeditiously, so the incinerators can meet the limits in 40 CFR 60 Subpart LLLL.
Post Point WWTP RO-52: The Washington State Clean Air Act provides a mechanism for facilities to request an enforceable limit on emissions of a pollutant from their operations. The clean air agency with jurisdiction can agree to this request and include emissions monitoring, reporting, and recordkeeping requirements to ensure that the requested limit is met.
On August 13, 2025, NWCAA issued Regulatory Order 52 (RO-52) to the Post Point Wastewater Treatment Plant. The Order, requested by the City of Bellingham and to which NWCAA agreed, establishes a limit on carbon monoxide (CO) air emissions from the existing incinerators. The Order requires continuous monitoring, recordkeeping and reporting to show whether the limit is being met. RO-52 does not approve, deny, or modify ongoing operation of the existing incinerators or any other equipment at the facility.
This is just one action that NWCAA and the City of Bellingham are taking to resolve alleged emission issues at Post Point. NWCAA and the City are engaged in ongoing discussions and the agency’s investigation is continuing at this time.
Post Point’s Application, RO-52, and the Worksheet that summarizes the technical basis for the Order:
NWCAA accepted public comments on the draft Order from April 12, 2025, through June 11, 2025, and conducted an in-person public hearing on the draft Order on June 11, 2025. Comments (written and verbal) were reviewed and grouped by content. NWCAA’s comment response is provided in the linked document below.
Pursuant to Section 123.1 of the NWCAA Regulations, this Order shall become final unless, no later than thirty (30) days after the date that the Order is served, any person appeals the Order to the Pollution Control Hearings Board as provided by chapter 43.21B RCW.
Additional information regarding appeal procedures can be found at https://eluho.wa.gov/boards/pollution-control-hearings-board.
