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Portable Diesel Engine ATCM Approved, Effective 11/30/18


Portable Diesel Engine Air Toxics Control Measure Revision Approved, Effective 11/30/2018

The California Air Resources Board (CARB) announced October 1, 2018 that the revisions to the Portable Diesel Engine Air Toxics Control Measure (ATCM) have been approved and will become effective on November 30, 2018. This regulation affects all owners of portable diesel engines > 50 hp unless otherwise exempt by applicability standards.

The most major changes to the revision include:

  • Updated engine phase-out schedule
  • Updated fleet average schedule
  • Low use engine exemption increased to 200 hours/year
  • Low use designation requirement: 6 months prior to phase-out
  • Early engine retirement incentives
  • Updated recordkeeping requirements
  • Prohibition of sale and change of ownership restrictions

Additionally, revisions to the Statewide Portable Equipment Registration Program Regulation have been approved to correspond with the ATCM changes and will become effective November 30, 2018.

Both of the final regulations showing the changes can be found on the CARB website at:

For questions regarding the changes and how they may affect your business, contact the District at (805) 781-5912 or contact CARB at