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File #: 25-1231    Version: 1
Type: Agenda Item Status: Approved
File created: 7/3/2025 In control: Board of Supervisors
On agenda: 10/21/2025 Final action: 10/21/2025
Title: HEARING - Air Quality Management District (AQMD) recommending the Board, acting as the AQMD Board of Directors: 1) Adopt and authorize the Chair to sign Resolution 141-2025, approving the amendments to Rule 239, Natural Gas-Fired Water Heaters Less than 1,000,000 BTU per Hour; and 2) Direct staff to forward the rule to the California Air Resources Board for transmittal to the U.S. Environmental Protection Agency as a revision to the State Implementation Plan. FUNDING: N/A
Attachments: 1. A - 2013 SIP Revision Report 1997 Std, 2. B - AQMD Legal Services Request, 3. C- Mountain Democrat Public Notice Proof of Publication, 4. D - Tahoe Daily Tribune Public Notice Proof of Publication, 5. E - AQMD REVISED RULE 239 NATURAL GAS-FIRED WATER HEATERS LESS THAN 1000000 BTU PER HOUR - Redline, 6. F - AQMD REVISED RULE 239 NATURAL GAS-FIRED WATER HEATERS LESS THAN 1000000 BTU PER HOUR-CLEAN, 7. G - AQMD Rule 239 Staff Report - Final, 8. H - 239 Rule BOS Presentation- October 2025, 9. I - Public Hearing Notice Rule 239-AB2588, 10. J - AQMD Proposed Rule 239 Resolution CoCo Reviewed, 11. FE Resolution 141-2025
Title
HEARING - Air Quality Management District (AQMD) recommending the Board, acting as the AQMD Board of Directors:
1) Adopt and authorize the Chair to sign Resolution 141-2025, approving the amendments to Rule 239, Natural Gas-Fired Water Heaters Less than 1,000,000 BTU per Hour; and
2) Direct staff to forward the rule to the California Air Resources Board for transmittal to the U.S. Environmental Protection Agency as a revision to the State Implementation Plan.

FUNDING: N/A
Body
DISCUSSION / BACKGROUND
The Sacramento Federal Nonattainment Area (SFNA) comprises Sacramento and Yolo Counties, the western portion of El Dorado and Placer Counties, the southern portion of Sutter County, and the northeastern portion of Solano County. AQMD is the agency responsible for maintaining the National Ambient Air Quality Standards (NAAQS) in El Dorado County.
Ozone is formed when volatile organic compounds (VOCs) and nitrogen oxides (NOx) undergo photochemical reactions in the presence of sunlight. In 2009, the AQMD Board and the Boards of other SFNA air districts approved the 1997 SFNA 8-hour Ozone Attainment and Reasonable Further Progress Plan (Plan), with revisions adopted in 2011 and 2013. This Plan demonstrates how existing and new control strategies will provide the necessary emission reductions to meet Clean Air Act (CAA) requirements for attainment of the 1997 8-hour ozone NAAQS. To achieve the additional reductions needed, the Plan included new control measures to be incorporated into the SIP. As part of these SIP commitments, the SFNA air districts agreed to adopt various control strategies and rule updates. Specifically, the Plan included a commitment for the AQMD to achieve NOx emission reductions from a water heater control measure within the heat input range of 75,000 to 1,000,000 Btu/hr.
The ozone NAAQS were first established in 1979 as a 1-hour standard. They were later revised to 8-hour standards in 1997, 2008, and 2015. The 1997 8-hour ozone NAAQS was s...

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