Environmental Permitting

Energy Systems specializes in permitting emergency standby and prime power engines, and can assist with all phases of the air permitting process, including but not limited to:

Regulatory applicability analysis
Determination of engine emissions and compliance requirements
Permitting strategy development
Emissions control technology evaluations
Completion of air permit applications
Emissions quantification
Air District negotiations

California Air Permitting

To achieve the objectives of the federal Clean Air Act (CAA), the United States Environmental Protection Agency (USEPA) has established permitting programs through its regional offices. USEPA has delegated authority over air permitting in California to the California Air Resources Board (CARB). Air permitting in California is administered at a local level through 35 individual air districts, that enforce federal and state regulations, as well as implement their own unique regulations, permitting policies, and procedures. As a result, air permitting covers a combination of federal, state, and local rules and regulations, as well as source-specific requirements.

Local air districts may impose more stringent requirements than the federal and state regulations, but they cannot have lesser requirements. Permitting and air emissions requirements vary by air district due to region-specific air quality issues (attainment status), as well as economic and environmental factors.

Air permitting is often a complex and lengthy process, and permitting requirements are continuously updated on a local level. Our expertise in California air permitting and compliance ensures you will receive the most up-to-date guidance on permitting requirements specific to your project. With our expert knowledge, Energy Systems can prepare and submit complete and accurate air permit applications, which streamlines the permitting process and helps secure the air permit for your project in a timely manner.

Who Needs a Permit?

CARB requires stationary engines rated 50 brake-horsepower (bhp) (equivalent to 37 kW) or greater to obtain an air permit issued by the local air district. A limited few air districts have permitting exemptions based on specific criteria (limited operational hours, fuel type, etc.). Any new or modified sources are required to obtain a permit. This includes replacement or modified engines. Engines that are moved to a new facility are also required to obtain an air permit.

Portable engines require equipment registration through the CARB Portable Equipment Registration Program (PERP). The Energy Systems can assist with PERP registration through our Rental Department.

What Types of Permits are Issued for Engines?

There are typically two parts to an engine air permit, which include:

Authority to Construct (ATC) – the ATC allows the permit holder to commence installation and construction of the equipment. Initial testing is permissible to establish equipment settings, test alarms, etc.
- The ATC is typically valid for a period of 12 – 24 months and can potentially be renewed. The equipment must be installed before the ATC expires

Permit to Operate (PTO) – once the equipment is ready for commissioning and operation, the permit holder is typically required to notify the Air District of the initial operational date. This may consist of a phone call, completion of a form, or regulatory inspection
- Once the Air District verifies that have received appropriate notification, and/or the inspection is complete, the Air District will issue the PTO
- Typically, the PTO is valid for a period of one to three years and must be renewed by the required deadline to remain valid

Tier 4F Requirements for Stationary Diesel Engines

CARB’s Air Toxics Control Measure for Stationary Compression-Ignition Engines (ATCM) sets forth the emissions standards and operational requirements for stationary diesel engines at the state level. Most air districts follow the state’s ATCM emissions standards, which require stationary diesel engines comply with the following:

Tier 3 compliance for engines rated 50 to <750 bhp
Tier 2 compliance for engines rated 750 bhp or greater
Particulate Matter (PM) emissions standard of 0.015 g/bhp-hr for all engines 50 bhp or greater

Due to the need to reduce regional diesel engine emissions, several air districts are now requiring Tier 4F certification or compliance for engines rated 1,000 bhp or greater, including:

Bay Area AQMD
Sacramento Metropolitan AQMD
San Luis Obispo AQMD

Other air districts are currently considering changes to their emissions requirements:

San Joaquin Valley APCD is currently considering updating their BACT guideline to require all emergency standby diesel engines rated 50 bhp or greater to be Tier 4F certified or compliant
South Coast AQMD is currently considering updating their BACT guideline to require emergency standby diesel engines rated 1,000 bhp or greater, and located at major source facilities, to be Tier 4F certified or compliant

Energy Systems can provide information and guidance on the latest regulatory developments to ensure that your equipment can secure an air permit. We are also able to provide Tier 4F solutions and emissions controls technology evaluations to help you determine the best solution for your project.