California’s South Coast Air Quality Management District (South Coast AQMD) Governing Board recently adopted Rule 2306, otherwise known as the Freight Rail Yards Indirect Source Rule (ISR), which requires rail yard operators to take actions to meet specific emission reductions targets.

The rule is expected to reduce NO_x emissions associated with freight rail yards by about 10.5 tons per day between 2027 to 2050.

The rule is designed to work together with the regulations recently adopted by the California Air Resources Board (CARB) and will ensure that rail yards in the South Coast Air Basin reduce emissions.

Freight rail yards subject to the rule will be required to achieve up to 82% emissions reductions by 2037 through a variety of actions including using cleaner technologies or lower emitting equipment associated with rail yards.

More than 80% of the NO_x emissions in the South Coast Air Basin are from mobile sources, and nearly half of these come from mobile sources associated with goods movement. Reductions in NO_x are essential to reducing smog and meeting federal clean air standards. Rail yard related emissions overall contribute about 9% of total smog-forming emissions in the region.

The rule applies to owners or operators of proposed, new, and existing freight rail yards located within South Coast AQMD’s jurisdiction. As part of the rule, owners and operators of freight rail yards will be required to report on the planning, development, and use of zero-emission infrastructure to support state regulations and meet broader federal and state zero-emission goals. The rule also requires state and local government agencies to require rule compliance when they enter, renew, or amend a contract with the facility owner or operator.

The Rail Yards ISR covers about 25 facilities located throughout the South Coast AQMD jurisdiction.

The Rail Yards ISR will become effective after EPA approves the Rail Yards ISR and CARB’s associated rules on locomotives and drayage truck fleets.

Freight rail yards covered by the rule are locations where locomotive switching activities occur or where cargo is loaded or unloaded from railcars for transportation to or from the rail yard using the rail yard operator’s locomotives. Emissions associated with freight rail yards are emitted from locomotives, drayage trucks, cargo handling equipment (CHE), and miscellaneous off-road equipment such as transportation refrigeration units (TRUs).

South Coast AQMD is the regulatory agency responsible for improving air quality for large areas of Los Angeles, Orange, Riverside and San Bernardino counties, including the Coachella Valley.