Air Toxics "Hot Spots" and Emissions Inventory Programs

SDAPCD prepares air emission inventories for criteria pollutants and toxic air contaminants for stationary sources, and is responsible for preparing air emissions inventory reports for stationary sources annually, biennially, or once every four years depending on the applicable requirements specified by Rule 19.3 and District policies.

The emissions included in an inventory are typically from stationary emitting devices required to have District permits located or operated at a stationary source. Emitting devices that are exempt from permit requirements may also be included in these emission inventories. Emissions from mobile sources, natural sources and accidental releases are not included in these emission inventories. SDAPCD provides emission calculation procedures on how to quantify emissions from various devices.

There are three main emissions inventory programs:

1. Criteria Pollutant Emissions Inventory (Rule 19.3) (CEI)

The Criteria Pollutant Emissions Inventory requires emissions of carbon monoxide (CO), lead (Pb), oxides of nitrogen (NOx), particulate matter (PM), oxides of sulfur (SOx) and volatile organic compounds (VOC’s) to be quantified.

2. Toxic Emissions Inventory and "Hot Spots" Program (California Health & Safety Code Sections 44300 – 44400) (TEI)

The Toxics Emissions Inventory or “Hot Spots” Program requires listed toxic air contaminants to be quantified.  

For the “Hot Spots” Program, once the toxic emissions are quantified, SDAPCD is required to prioritize and categorize the subject facilities to determine if a health risk assessment is warranted. SDAPCD utilizes a prioritization procedure which takes into consideration potency, toxicity, quantity of emissions and proximity of the facility to potential receptors and any other factor that SDAPCD finds may indicate that a facility poses a potential risk to receptors. The prioritization procedure categorizes the facilities as a high, intermediate or low priority. Facilities categorized as “high” are subject to health risk assessment (HRA) requirements. Facilities categorized as “intermediate” may be subject to HRA requirements. Facilities categorized as “low” are not subject to HRA requirements.

Facilities required to submit a HRA are no longer required to submit a HRA protocol for District review. SDAPCD will review and verify that the HRA was conducted in compliance with the HRA Guidelines adopted by the State Office of Environmental Health Hazard Assessment (OEHHA) and SDAPCD’s "Hot Spots" Supplemental HRA Guidelines.

3. CARB’s Criteria and Emissions Inventory Guideline Regulations (CCR Title 17 Section 93400) (CTR)

On November 19, 2020, California Air Resources Board (CARB) adopted amendments to the proposed Regulation for the Reporting of Criteria Air Pollutants and Toxic Air Contaminants (CTR). These amendments include expanded applicability to most facilities that have been issued a Permit to Construct and/or a Permit to Operate with SDAPCD except for those listed in Title 17 CCR 93401 (b) as follows:

  • The following facility/entities that are subject to reporting greenhouse gas emissions pursuant to Title 17, CCR 95101:
    • Suppliers of Transportation Fuels
    • Electric Power Entities
    • Natural Gas Distribution Facilities
  • Emission associated with the following sources are also excluded from applicability determinations:
    • Emissions from internal combustion engines used for irrigation pumps
    • Emissions from open burning – fields, agricultural waste, prescribed forest burns or permitted open burning
    • Emissions from tactical support equipment

SDAPCD staff have made best efforts to help identify facilities that are subject to reporting. SDAPCD has prepared a list of facilities which are required to report data year emissions. Some facilities may not be included on this list based on specific emissions or activity levels which are not available to SDAPCD to assess. Please note that this list is not encompassing of all facilities required to report and if a facility is not listed, that does not mean it is exempt from reporting.

Any facility with an active permit should complete their own applicability assessment to determine if reporting is required.

SDAPCD will mail and email Data Request letters to the facilities listed and any other facility subject to the CTR reporting requirements, using best available contact information on file with SDAPCD. If your facility did not receive a Data Request Letter and is subject to CTR Reporting, please contact us at to request a letter.

List of Facilities Required to Report 2023 Data

Sample 2023 Data Request Letter

SDAPCD has a web-based program called EIS (Emissions Inventory System) to report data and compile the emissions inventory. EIS allows facilities to review data requested, provide required inventory information, and see their resulting inventory online. EIS instructions, including information related to registration can be found on the EIS homepage.