In California, a C-57 specialty contractor is a well drilling contractor that "installs and repairs water wells and pumps by boring, drilling, excavating, casing, cementing and cleaning to provide a supply of uncontaminated water." Cal. Code of Regs., Tit. 16, Div. 8, Art. 3. In its Industry Bulletin 14-04, the California Contractors State License Board (CSLB) reminds C-57 licensees that certain portable engines to power well drilling equipment require registration.

C-57 licensees must register their fuel-powered portable internal combustion engines of 50 horsepower or greater used to power drilling equipment either with:

  1. the State using the Statewide Portable Equipment Registration Program (PERP) to operate their equipment using the engines throughout the state without stationary source construction and operating permits from local air districts, or
  2. (A) those C-57 licensees who drill within the San Joaquin Valley Air Pollution Control District (District), which includes San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, Tulare and part of Kern, may register equipment under Rule 2280 (Portable Equipment Registration), and (B) those C-57 licensees whose work takes them beyond the District, may register their equipment with the California Air Resources Board (CARB).

The Industry Bulletin also reminds licensees that the District also regulates the use of internal combustion engines used on a temporary basis to power agricultural wells while they are being connected to electric power. Use of this type of engine requires a permit from the District depending on the size of the farm. Farms subject to District permits must obtain an Authority to Construct (ATC) permit from the District in order to install and operate a new IC engine greater than 50 horsepower (continuous rating). Farms that are exempt from District permits require a District Permit-Exempt Equipment Registration (PEER) for each engine greater than 50 horsepower (continuous rating). For more information, read San Joaquin Valley Air Pollution Control District, Compliance Assistance Bulletin 2014, Electrification of New Irrigation Wells.