California Air Regulations:
In-Use Off-Road Diesel Vehicle Regulation
Portable Diesel-Fueled Engines Air Toxic Control Measure (ATCM)
By Greg Buncab
14 SOURCE summer 2013
News and Views on Issues, Legislation and Regulations
Because air regulations cover such a wide
array of operations and equipment, maintaining
an air compliance program can be a
daunting task for utilities. Even more challenging
is staying up-to-date on air regulations
that are constantly evolving.
Not only must utilities comply with local
air district regulations, they must also meet
statewide air quality regulations that are
typically administered by the California Air
Resources Board (ARB). ARB has several
regulations aimed at reducing air pollutants
throughout the state, and diesel regulations,
specifically, tend to have an impact on utilities
because of their numerous stationary
and mobile diesel sources. Two specific ARB
regulations with continuous compliance
dates are the In-Use off Road Diesel Vehicle
Regulation and the Portable Diesel-Fueled
Engines Air Toxic Control Measure (ATCM).
The In-Use off Road Diesel Vehicle Regulation
applies to all self-propelled off-road diesel
vehicles over 25 horsepower (hp). On
February 11, 2010, ARB issued a delay of
the regulation’s NOx and particulate matter
(PM) requirements pending further notice.
However, reporting, labeling, idling and
disclosure requirements are still in effect.
Dependent on fleet size, annual reports are
due by March in the years indicated below:
1. Large fleets (those with 5,000 + hp) must
report annually each year from 2012 to
2. Medium fleets (those with 2,501-5,000
hp) must report annually each year from
2016 to 2023.
3. Small fleets (those with up to 2,500 hp)
must report annually each year from
2018 to 2028.
ARB’s Portable Diesel-Fueled Engines ATCM
is another regulation that impacts utilities.
This rule applies to portable diesel-fueled
engines having a rated brake horsepower of
50 and greater. The ATCM fleet standards
went into effect as of January 1, 2013. Fleets
are subject to more stringent weighted
PM emission fleet averages by January 1
in 2013, 2017 and 2020. The ATCM also
requires owners of portable engines to
submit a statement of compliance signed by
a Responsible Official to the ARB by March
1 in 2013, 2017 and 2020. In addition to the
statement of compliance, a summary that
identifies each portable engine in the fleet
and the associated emission rate (g/bhp-hr)
must be included.
To make compliance with air regulations
easier, it is imperative that utilities maintain
current records of all engines and equipment
in their fleet. A good compliance program
is based on being proactive and maintaining
consistent record-keeping. Utilities
can stay up-to-date on air regulations by
contacting their local air quality district or
visiting the ARB website at http://www.arb.
Greg Buncab is Environmental Specialist at
Alameda County Water District. He has also
served as ACWD’s project manager for Air
Compliance, Wastewater Discharges and
National Pollutant Discharge Elimination
System (NPDES) programs.
Regulation Applies To Comments
Stationary compression ignition engines used in both
non-agricultural and agricultural operations.
These engines are typically permitted through the local air district.
Operating conditions are dependent on engine type and use.
Fleet Rule for Public
Agencies and Utilities
Any municipality or utility that owns, leases, or operates
on-road diesel-fueled heavy-duty vehicles with 1960
model year or newer heavy-duty engine.
The major compliance dates have already passed but continuous
compliance is required (i.e. recordkeeping, vehicle labeling and
Idling On and off-road diesel engines. Limits idling of diesel engines, especially around schools. There
are some exemptions to the rule.
Periodic Smoke Inspection
All heavy-duty diesel-powered vehicles that are
æ6,000 lbs. GVWR or greater.
In 2010 there were changes to Smog Check requirements.
The link for the ARB advisory is: http://www.arb.ca.gov/enf/
All diesel-powered and gasoline powered
This regulation requires vehicles to have a legible emission
control label for ARB inspectors to verify the emission standards
of the engine.