PUBLIC NOTICE
PUGET SOUND CLEAN AIR AGENCY
PROPOSED ORDERS OF APPROVAL
and
DRAFT AIR OPERATING PERMIT
Applicant:
King County West Point Wastewater Treatment Plant
1400 Discovery Park Blvd
Seattle WA 98199
Puget Sound Clean Air Agency (the Agency) is seeking comments on two proposed Notices of Construction Order of Approvals (NOCs 11470 & 10107) and draft Air Operating Permit (Permit No. 10088) for the King County West Point Wastewater Treatment Plant located at 1400 Discovery Park Blvd, Seattle, WA, 98199. This facility is a municipal wastewater treatment plant serving central King County. Facility operations result in releases of volatile organic compounds, oxides of nitrogen, carbon monoxide, sulfur dioxide, particulate matter, hazardous and toxic air pollutants.
The proposed Order of Approval 10107 is for the addition of air-to-fuel ratio controls and 3-way catalysts for each of four Waukesha L5790G- 600 HP raw sewage pump internal combustion engines, fueled with biogas pre-scrubbed for hydrogen sulfide and siloxane, with propane as backup emergency fuel. This Order also includes a change in the units of measure from g/bhp-hr to ppm at 15% O2 for emissions of NOx and CO. This will allow for clearer compliance determinations and will result in a reduction in emissions. This Order of Approval cancels and supersedes an earlier Order of Approval issued in 1992.
The proposed Order of Approval 10470 is for Two Caterpillar G3612 Lean Burn Engine Generators rated at 3,221 hp at 100% load each and combusting digester gas. The engines are part of a 4.6 Megawatt cogeneration system that generates heat for the West Point facility and generates electricity for sale to Seattle City Light. This Order approves cancelling and superseding OA 8914 and changing the units on the engine exhaust emission limits from g/bhp-hr to ppm at 15% O2 . It also includes periodic monitoring and testing of the engines and compliance methods for the PSD synthetic minor limits that were originally included in OA 8914. OA 8914 contained the emission limits for NOx and CO, but did not contain compliance methods.
These proposed Orders of Approval are included in this public notice for comments along with the draft Air Operating Permit. These actions are concurrent because the proposed projects contravene terms in the existing Air Operating Permit and cannot be issued until the Air Operating Permit is put out for public notice and modified or renewed. There has not been a modification to the existing Air Operating Permit to include these two projects and this is the first renewal of the existing Air Operating Permit. It is also the first time that the terms of the Air Operating Permit can be modified or enhanced to include the conditions in the two Orders of Approval.
An Air Operating Permit is a document that combines all air pollution-related requirements for operation and procedures, applicable rules, emission standards, monitoring, recordkeeping, and reporting. The draft Air Operating Permit is a renewal of the current Air Operating Permit that is already in force. Air Operating Permits expire every five years and need to be renewed. This renewal incorporates all the new compliance requirements that have come into effect for the facility since the previous Air Operating Permit was issued.
Copies of the draft Air Operating Permit, the application, and all supporting materials are available below for review:
How to Comment
The Agency will accept comments on this permit starting January 25, 2024 until February 23, 2024.
Send comments by e-mail to: PublicComment@pscleanair.gov
Send written comments to:
Air Operating Permit Program
Puget Sound Clean Air Agency
1904 Third Ave, Suite 105
Seattle, WA 98101
A public hearing may be held if the Agency determines that there is significant public interest. Requests for a public hearing must be submitted within the comment period. Any such request for a public hearing must indicate the interest of the person or organization filing it, and describe why a hearing is necessary.
This Notice is published pursuant to the Washington State Clean Air Act (Chapter 70A.15 RCW and WAC 173-401-800). The Air Operating Permit is issued pursuant to Chapter 173-401 WAC and Title V of the Federal Clean Air Act Amendments of 1990.
Air Operating Permits are also subject to review and approval by US EPA. If a public comment is sent to the Agency for this permit, and the Agency has not addressed the comment in a satisfactory manner, and the EPA has not objected to the proposed permit, then the public may submit a petition requesting that the EPA reconsider the decision not to object. Petitions shall be submitted electronically to US EPA at TitleVPetitions@epa.gov or by mail to US EPA, Office of Air Quality Planning and Standards, Air Quality Policy Division, Operating Permits Group Leader, 109 T.W. Alexander Dr. (C-504-01), Research Triangle Park, NC 27711. Petitions shall be submitted within 60 days after the end of the 45-day EPA review period. The EPA review period for this permit starts no earlier than March 30, 2023.