On August 20, 2019, the San Diego Air Pollution Control District (SDAPCD) released a public notice proposing a major overhaul of permitting and emission control requirements for boilers, water heaters, steam generators, and process heaters. The proposed changes will require a large amount of retroactive permitting and registration activity for existing units that were previously exempt from permitting requirements. Additional changes are proposed to restrict emissions from new fuel combustion units to reduce their impact on the area's ozone nonattainment status, and require annual tune-ups of larger new and existing combustion equipment. The proposed changes will require all new and existing boilers, process heaters, and steam generators with a heat input rating of 2 to 5 MMBtu to obtain a District permit or registration.

The proposed amendments to Rule 69.2.1 will limit NOX emissions for new boilers, process heaters, steam generators, and water heaters to 20 ppmv when operated on natural gas and 30 ppmv when operated on other fuels. Emissions of CO would be limited to 400 ppmv for all fuels. The limits will apply to units as small as 75,000 Btu/hour and up to 2 million Btu/hour; the expanded size range reaches units so small as to affect even light commercial water heaters and residential tankless water heaters. Sale of affected equipment would be illegal for sale in San Diego County unless the manufacturer submits a certification of compliance in advance to SDAPCD, on a per model number basis, at least 30 days in advance of offering any affected unit for sale. The shipping carton and nameplate of every unit sold would be required to show the certification status of the unit with respect to this rule or the equivalent South Coast Air Quality Management District Rule (1146.2).

The proposed new Rule 69.2.2 will require all boilers, process heaters, and steam generators with a heat input rating of 2 to 5 million Btu/hour to be tuned up by July 1, 2021 and annually thereafter. The tune-ups would require measurement of exhaust NOX and CO concentrations using a portable instrument. Recordkeeping of tune-ups would be required for compliance demonstration. All units subject to the new rule without a current permit to operate (PTO) will be required to apply for a permit or registration by January 1, 2021. Additionally, new boilers, process heaters, and steam generators of the same sizes would be limited to exhaust concentrations of NOX of 30 ppmv when operated on gaseous fuels and 40 ppmv when operated on liquid fuels. Emissions of CO would be limited to 400 ppmv for all fuels. New units would also be subject to certification requirements similar to those described in the previous paragraph, but the certification for each model number in this size class would not be effective until specifically approved by the District. Annual tune-up measurements for new units subject to these emission limits would be expected to continue to demonstrate compliance with the limits. Units capable of firing liquid fuels would be subject to additional fuel usage monitoring and recordkeeping requirements.

The public notice for the proposed rules and amendments can be reviewed on the SDAPCD's website. For more information regarding the proposed rules and amendments, please contact our Irvine office at (949) 567-9880.