South Coast Air Quality Management District (South Coast AQMD) Proposed Rule 2306 sets emission reduction targets and mandates zero-emission infrastructure reporting for new and existing freight rail yards to help meet California and National Ambient Air Quality Standards (CAAQS & NAAQS). The rule was sent to board consideration on August 2, 2024 and is assumed to be approved with minimal changes to the draft language.
The rule focuses on reducing NOx emissions from freight rail yard operations by setting reduction targets that match or exceed statewide standards. State or local government agencies contracting with freight rail yard owners must include compliance requirements in their agreements. Operators must meet the NOX emission reduction targets for each Milestone Year for each freight rail yard that it operates.
Table 1
| Calendar Year | % Emission Reduction Target | Calendar Year | % Emission Reduction Target |
| 2027 | 9.2 | 2039 | 13.2 |
| 2028 | 13.6 | 2040 | 13.2 |
| 2029 | 16.9 | 2041 | 13.2 |
| 2030 | 13.1 | 2042 | 13.2 |
| 2031 | 13.1 | 2043 | 13.2 |
| 2032 | 13.1 | 2044 | 13.2 |
| 2033 | 13.1 | 2045 | 13.2 |
| 2034 | 13.1 | 2046 | 13.2 |
| 2035 | 13.1 | 2047 | 13.3 |
| 2036 | 13.2 | 2048 | 13.3 |
| 2037 | 13.2 | 2049 | 13.4 |
| 2038 | 13.2 | 2050 | 13.4 |
South Coast AQMD has released a Draft Calculation Methodology, which provides additional guidance regarding the calculation methodology. Based on this draft methodology, operators will be required to meet the NOX emissions reduction targets listed in Table 1 through the replacement of the following equipment with cleaner or ZE alternatives:
- Locomotives
- Drayage Trucks
- Transport Refrigeration Units (TRU)
- Cargo Handling Equipment (CHE)
- Other On-Site Support Equipment (OSE)
Important Clarifications
- The throughput is total number of visits by railcars that move through the yard over a set period.
- The Base Period is the first 2 years after the rule is passed.
- Milestone Year (MY) means any of the calendar years including the third calendar year immediately after the calendar year when the rule becomes effective and every third calendar year thereafter.
Rule 2306 Reporting Requirements
The table below shows the various reporting requirements and respective due dates.
Table 2
| Report | Due Date |
| Initial Facility Information Report (IFIR) | 90 Days After Base Period / Shutdown Date |
| Initial Zero Emission Infrastructure Report (IZIR) | 120 Days After Base Period |
| Milestone Compliance Report (MCR) | July 15th After Milestone Year / 90 Days After Shutdown Date |
| Zero Emissions Infrastructure Status Update Report | October 15th After Milestone Year (MY) |
Initial Facility Information Report (IFIR)
The IFIR is due 90 days after the Base Period and requires the following information:
- Freight Rail Yard Basic Information
- Applicable Mobile Sources Information
- Number of Calendar Days with Switching Activities for Each Base Year
- Annual Throughput & Annual Average Throughput for each year of the Base Period
- Annual Aggregate Emissions Factor (average rate of NOX emissions per unit of energy consumed) for each calendar year
Initial Zero Emission Infrastructure Report (IZIR)
The IZIR is due 120 days after the Base Period and requires the following information:
- A descriptive list of on-site and off-site zero emissions (ZE) infrastructure that has previously been designed, developed, or installed to comply with regulations, such as the In-Use Locomotive Regulation or the Advanced Clean Fleets Regulation, and specify any future on-site and/or off-site ZE infrastructure that will be used for compliance.
- A descriptive list of installed and operative over the Base period and any ongoing or planned ZE infrastructure.
The operator is required to submit a request to the local electrical utility to upgrade the electrical service within 180 days after submitting the IZIR.
Milestone Compliance Report (MCR)
The MCR is due by July 15th after the Milestone Year and requires the following information:
- Any changes compared to the IFIR or the most recent MCR.
- Applicable Mobile Sources
- Number of Calendar Days with Switching Activities
- Annual Throughput for the MY and the previous two calendar years
- Annual Aggregate Emissions Factor with detailed calculations
- Emissions Reduction Target
- Demonstration of compliance via calculations
Zero Emissions Infrastructure Status Update Report (ZSUR)
The ZSUR is due by October 15th after the Milestone Year and requires the following information:
- Any ZE infrastructure on-site or off-site that has been designed, developed, or installed since the IZIR or the most recent ZSUR
- Any updates for future needs for on-site or off-site ZE infrastructure
- Information about the MY including any ZE infrastructure installed, being installed, or planning on being installed.
Additional requirements such as notifications and fees can be found in the draft rule language.
CARB In-Use Locomotive Regulation
For more information on CARB requirements, please see our overview of CARB’s In-Use Locomotive Regulation. In addition, please see our article discussing how this Regulation and Rule 2306 differ and overlap.
Trinity can assist with reporting, calculations, and compliance strategies with both rules. If you have any questions regarding the rule and maintaining compliance for your facility, please email Tiffany Wang or Trinity’s Irvine office.
