Last updated: August 31st, 2026
C-57 Well Drilling contractors who use portable internal combustion engines need to be aware of California air-quality permitting and registration requirements.
Depending on the engine, equipment, horsepower, operating location, and how the equipment is used, you may need to register the equipment or obtain a permit through:
For contractors operating in the San Joaquin Valley, the San Joaquin Valley Air Pollution Control District’s Rule 2280 is particularly important.
Portable auxiliary engines rated at 50 horsepower or greater may require a permit or registration to operate legally in California.
But don’t interpret 50 horsepower as meaning every engine automatically follows the exact same permitting or registration process.
The requirements depend on factors such as:
California has numerous local air districts, and portable equipment that isn’t registered through PERP may be subject to the permitting or registration requirements of the district where it operates.
Before putting an engine into service, determine which rules apply to that specific equipment.
For C-57 contractors working within the San Joaquin Valley Air Pollution Control District, Rule 2280 governs the District’s Portable Equipment Registration program.
One important update for older articles and bulletins:
Rule 2280 was amended on December 20, 2018.
Contractors should therefore use the current version of Rule 2280 rather than relying on older guidance or the original 2014-era compliance information.
You can review the current Valley Air District rules for the latest version.
The San Joaquin Valley Air Pollution Control District covers:
If you’re operating well-drilling equipment in these areas, check the District’s portable-equipment requirements before beginning work.
Yes, depending on the equipment.
The Valley Air District specifically identifies portable engines used for activities including:
But the equipment still has to satisfy the District’s definition of a portable emissions unit.
Simply putting an engine on wheels or a trailer does not automatically make it eligible for portable registration.
Under the Valley Air District’s current Rule 2280 framework, equipment must actually qualify as portable.
Among other requirements, the unit must generally:
The District currently explains that qualifying portable equipment generally cannot remain at one non-storage location for more than six months.
Equipment can also lose eligibility for portable registration when its operation effectively becomes part of an ongoing stationary source.
If your drilling rig or engine will remain at a site for an extended period, confirm its status with the District before assuming portable registration applies.
For contractors who operate qualifying portable engines or equipment across multiple air districts, the California Air Resources Board operates the Portable Equipment Registration Program (PERP).
PERP is a statewide registration program.
Qualifying equipment registered through PERP can generally operate throughout California without obtaining a separate operating permit from every local air district where the equipment is used.
That can be particularly useful for C-57 contractors whose drilling operations move between different regions of California.
You can review the current CARB Portable Equipment Registration Program for current requirements.
The purpose of PERP is to provide a statewide registration option for qualifying portable engines and equipment.
Without PERP, a contractor operating portable equipment in several air districts may otherwise need to comply with the individual permitting or registration requirements of each district.
However, PERP registration is not automatically available to every portable engine.
The engine or equipment must satisfy CARB’s current eligibility requirements.
CARB’s current requirements vary based on factors including:
For example, current initial-registration requirements for many diesel engines rated from 50 to 750 bhp are tied to specific Tier 4 or qualifying flexibility standards.
Different rules apply to engines above 750 bhp and certain special engine categories.
Don’t purchase or put an engine into service based solely on horsepower and assume that PERP registration will be available.
Check the current eligibility requirements first.
CARB maintains current application, reporting, and recordkeeping forms through the Portable Equipment Registration Program.
Importantly, CARB currently accepts PERP registration applications and reports by email.
Use the latest forms and submission instructions rather than relying on older paper-only procedures.
You can access the current PERP Application, Record Keeping & Reporting Forms.
For questions about the program, CARB currently lists:
For a C-57 contractor, the right path may depend on where the equipment will be used.
This may make sense when:
This may make sense when:
Registration under either system still comes with operating, recordkeeping, emissions, and other compliance requirements.
Valley Air District Rule 2280 does not impose one identical technical requirement on every piece of portable equipment.
The District states that technology and operating requirements can vary depending on the:
Each District registration contains conditions intended to ensure the equipment complies with applicable rules.
That’s another reason contractors should avoid relying on simplified advice such as:
“Every engine over 50 horsepower needs the same registration.”
It doesn’t work that way.
Before operating portable well-drilling equipment in California:
No.
A 50+ hp portable engine may be subject to permitting or registration requirements, but PERP is one possible statewide registration path, not an automatic requirement for every engine.
The applicable requirements depend on the engine, equipment, eligibility, location, and local air-district rules.
Potentially, yes.
The San Joaquin Valley Air District specifically lists engines used for well drilling and servicing among equipment that may be eligible for portable registration.
The engine still has to satisfy Rule 2280’s eligibility requirements.
The current District rules list Rule 2280 as last amended on December 20, 2018.
Contractors should follow that current rule rather than relying on earlier bulletins or pre-2018 versions.
PERP is CARB’s Portable Equipment Registration Program.
It provides qualifying portable engines and equipment with a statewide registration option that can eliminate the need to obtain separate local operating permits in each air district.
Qualifying PERP-registered equipment can generally operate throughout California without individual operating permits from each local air district.
However, operators must still follow PERP requirements and other applicable state and local rules.
Generally, no.
For Valley Air District registration, equipment must satisfy Rule 2280’s definition of portable equipment. The District currently explains that a portable unit generally cannot remain at the same non-storage location for more than six months.
Use CARB’s current PERP Application, Record Keeping & Reporting Forms.
C-57 Well Drilling contractors using portable engines need to look beyond horsepower alone when determining California air-quality requirements.
The key points are:
For Central Valley work, review the Valley Air District Portable Equipment Registration resources.
For statewide registration, review the CARB Portable Equipment Registration Program.
