Asphalt Plants, Storage Silos, Tanks and Associated Equipment

Asphalt Associated Equipment

Asphalt plants and associated equipment including storage silos, tanks, aggregate handling equipment and related processes emit air contaminants including oxides of nitrogen, carbon monoxide, volatile organic compounds, oxides of sulfur, particulate matter and toxic air contaminants. This equipment requires a permit to operate.

Hot mix asphalt plants typically include storage hoppers, silos and material conveyance equipment for aggregate and liquid asphalt used to make the asphaltic concrete. The main plant consists of separate or a combined dryer and mixing drum/barrel including a large burner (typically natural gas or propane fired). The mixture is transferred to storage silos loaded into trucks for transport to paving projects. The plants typically require a hot oil heater to maintain the liquid asphalt at correct temperature/viscosity. Plants may also include mixing and blending tanks for producing rubberized asphalt or other specialty asphalt products. Emissions are controlled through a variety of means, typically including water to minimize dust during aggregate transfer, condensers to prevent vapor emissions from liquid storage tanks, controlled combustion/low-NOx burners to minimize combustion emissions, a baghouse to remove particulate from the dryer/drum exhaust and a blue smoke control filter to collect vapor, smoke and odor emissions during transfer, storage and load-out to transport trucks.

Asphalt Associated Equipment

This page also contains application information for permitting stand-alone asphalt tanks/kettles that are not eligible for portable registrations. For registering asphalt (roofing) kettles, see the Registration Page.

The information on this page will assist in the completion and submittal of an application for each plant. Each section of the page contains important information needed to submit an application.

Application Forms

Application forms tell us about your operation and allow us to permit your process. Accurate and complete information decreases processing time and helps avoid additional charges for unnecessary revisions. Please carefully review and complete the following forms. Also listed below are required attachments that need to be submitted with the application. You may contact the District with any questions.

General Application Word PDF

Asphalt Kettle Supplemental Form (no emission controls) Word PDF

Asphalt Kettle Supplemental Form (with emission controls) Word PDF

Toxics Form Word PDF

Required Attachments (for asphalt kettles/tankers only):

    Control equipment specifications (if applicable)

Required Attachments (for asphalt plants):

    Plot Plan including location of all emission points and nearby building dimensions

    Manufacturer emission data and emission calculations

    Proposed material throughputs

    Equipment specifications/data sheets including operating parameters and process flow diagrams

    Control equipment specifications (if applicable)

    BACT analysis including manufacturer/supplier cost estimates (if applicable)

    Actual emissions from existing facility (for major sources)

The general and equipment specific application forms along with required attachments must be submitted with each application packet.

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Estimated Fees

The correct fee must be submitted with your application in order for it to be accepted. For this type of equipment, fees are determined based on the time and materials required to conduct the review, so a fee estimate must be obtained from the District prior to submittal. Please note that application fees are estimated and the final fee may be more or less than this amount based on time and materials spent processing the application. The District maintains work records for this purpose.

Before submitting an application, contact the District (see bottom of page) to obtain an application fee estimate for application submittal. Please note that an additional fee may also apply depending on the method of payment. A breakdown of how the application fee(s) are determined can be seen here. Additional information can be found in District Rule 40.


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How to Pay

These fees may be paid by check payable to "Air Pollution Control District" or by credit card (Visa, MasterCard, Discover, and American Express). 

If you choose to email or fax your application and intend on paying with a credit card, you must provide contact information (name and phone number) so that the District can complete payment.

Please note that credit card payments are assessed a transaction fee of 2.19% that is charged by the credit card provider.

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Best Available Control Technology

If a piece of equipment or a process emits more than 10 pounds per day of particulate matter (PM10), oxides of nitrogen (NOx), volatile organic compounds (VOC) or oxides of sulfur (SOx), the application must include a best available control technology (BACT) analysis. Asphalt plants often trigger BACT requirements for any or all of these pollutants. Please note that the 10 pounds per day threshold is based on emissions for the entire process line including fugitive emissions from haul roads and storage piles and any other associated equipment. 

The District has a BACT guide to assist with the analysis. If you have questions or need assistance reference the contact information at the bottom of this page. Please review District Rules 20.1 and 20.2

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District Rule 1200 applies to any new, relocated, or modified emission unit which may increase emissions of one or more toxic air contaminant(s). The proposed project must comply with Rule 1200. Proposed equipment may require toxics best available control technology (TBACT) depending on the project. Please review District Rule 1200 for further details. 

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Trade Secret

District rules address how information that is submitted to the District is managed. District Regulation IX contains District rules 176 and 177. Please refer directly to these rules when submitting trade secret information. However, be aware that you will need to submit:

1.       A letter disclosing the proprietary information. This can be submitted electronically.

2.       A letter for the public record explaining why the information needs to be held as trade secret.

The inclusion of proprietary information can significantly delay permit applications. In an effort to expedite the permit application process it is recommended that you contact the manufacturer or vendor of any proprietary materials that are used in the process and prepare the required letters as part of your application submittal. 

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In 1989, the California state legislature passed a law, AB 3205, designed to protect schoolchildren from hazardous air contaminants. The law, as currently written, requires the District to notify parents of schoolchildren, neighboring businesses and residents of all new or modified equipment that emits any hazardous air contaminant into the air which will be installed within 1,000 feet of a school site. The law also requires the District to consider any comments before authorizing construction. Please review your proposed location. If a school property boundary is located within 1,000 feet of the proposed emissions point, the AB3205 process will be initiated. This process requires a 30 day public comment period and the overall process will delay projects by at least six weeks.

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How to Submit Application Packet



Permit Processing

10124 Old Grove Rd

San Diego, CA 92131-1649


(858) 586-2601

Select equipment type applications can now be submitted online through Citizen Access. Sign up today to get connected to your applications and permits. 

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Application Status

The District is required to act on complete applications within 180 days. If a specific turnaround time is required, discuss this with the assigned engineer. More complex processes will take longer. Ensuring your application is complete is the best way to reduce processing time. Complete emissions data is the most important factor in minimizing application processing time and iterative information requests. If you have any questions about what information is required, please contact the District using the information at the bottom of this page. Learn more about the rules that govern application processing time. 

Sign up for Citizen Access to get up to date information on the status of your application.

Learn more about the application process and what to expect.

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Asphalt plants are subject to a federal New Source Performance Standard (NSPS) which is implemented by the District:

NSPS I - Contains emission standards for particulate matter and required performance tests.

The engineer assigned to an application will review the proposed equipment to determine the requirements of these regulations that may apply to the asphalt plant and include them as conditions in your authority to construct.

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District Rules

Several District rules may apply to your equipment. General rules that may apply to asphalt plants and tanks/kettles include Rules 5051525354 and 62.

There are no equipment specific rules that apply to this equipment. A complete listing of the District's rules can be found here.

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Calculation Procedures and Additional Resources

Asphalt Production Calculation Procedures - This page contains procedures to be used for calculating emissions from the asphalt production portion of the equipment that should be submitted with each application if applicable. 

Haul Road Calculation Procedures - This page contains procedures that should be used to calculate emissions from any of the plant's haul roads.

Mineral Products Industry Calculation Procedures - This page contains procedures that should be used to calculate emissions from equipment such as crushers, screens, conveyers, storage piles and other mineral products industry related emissions associated with the process that occur on-site.

Combustion Equipment Calculation Procedures - This page contains procedures that should be used to calculate emissions from any hot-oil or other process heaters (emissions from the dryer should be calculated using the asphalt production calculations procedures). 

Use of these calculation procedures will aid in minimizing application review time and costs. The calculation procedure can be found at the link at the top of each page, and the correct emission factors selected from the list based on equipment. If available, manufacturer provided equipment specific emission data or source test results should be utilized before using default emission factors. Sources of all emission data used must be included as attachments to the application.

 - An alternative compilation of emission factors and calculation procedures prepared by the EPA that may be utilized by the District in some situations for some equipment types. 

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Obtain Assistance

Need Help? Have Questions?

Email the District or call (858) 586-2600 and ask for the duty engineer.

More in depth help and site visits can be performed by the District Small Business Assistance Program Coordinator who can be reached at (858) 586-2656.

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