South Coast Air Quality Management District (SCAQMD) Rule 462 – Organic Liquid Loading governs emissions of volatile organic compounds (VOCs) from facilities that load organic liquids (such as gasoline, ethanol, and other petroleum products with a true vapor pressure (TVP) ≥ 1.5 psia) into tank trucks, trailers, or railcars. The Rule covers various points in the fuel distribution network, including large bulk terminals and refinery loading racks, smaller bulk gasoline plants, and any facility that transfers gasoline into tanker trucks. In its current form, the Rule classifies facilities by size/throughput: Class A for large terminals and major loading operations (loading ≥20,000 gallons in a day), Class B for intermediate facilities, and Class C for very small pre-1976 facilities (≤4,000 gallons/day and ≤500,000 gallons/year).

Rule 462 was last amended just over 25 years ago in 1999. These latest proposed amendments to the Rule have now been approved as of August 1, 2025, due to community air quality concerns and the region’s extreme ozone nonattainment status under the National Ambient Air Quality Standards (NAAQS). In response to these drivers, SCAQMD has developed amendments to Rule 462 to require more advanced leak detection technology and stricter emission limits at facilities that conduct Organic Liquid Loading, such as bulk gasoline plants, terminals, refineries, and some gasoline stations.

Stricter VOC Emission Limits

Amended Rule 462 lowers VOC emission limits exclusively for Class A facilities, leaving Class B and Class C emission limits unchanged. A summary of the VOC emission limit changes is provided in the image below.

TABLE 1

Large Class A facilities, such as bulk terminals and refinery loading racks, are the primary targets of the Rule 462 amendments. As of the amended rule, the VOC limits for Class A facilities are reduced from 10 mg/L (ten milligrams of VOC per liter of organic liquid loaded) down to 5 mg/L.

Fortunately, as noted by the SCAQMD Draft Staff Report, a review over Class A facilities’ source tests indicates that some facilities have vapor recovery systems that already demonstrate compliance with the 5 mg/L limit with their existing controls. Thus, the primary intent of the amendments is not to mandate new installations or retrofit existing units, but rather to ensure continued high emission control performance and to verify compliance by periodic source testing.

Periodic Source Testing

To ensure that the lower limits remain achievable in practice, PAR 462 now includes requirements for periodic source testing at Class A facilities. Under the current Rule 462, source testing frequency has been dictated by facility-specific permit or Title V conditions, with no uniform schedule embedded in the rule itself. The amendments change this by formally requiring Class A facilities to conduct source testing every sixty (60) months EPA Method 25A, 25B, or SCAQMD Method 501.1.

In addition to the five-year testing interval, the amendments set standardized requirements for testing protocols, notice to SCAQMD, and report submittal timelines. Facilities must submit and obtain approval of a source test protocol before conducting testing, notify the District at least ten (10) days in advance, and submit final results within sixty (60) days of sampling. Tests conducted under SCAQMD’s approval procedures must use District-approved laboratories.

For facilities not already on a five-year cycle, the rule sets transition deadlines: protocols must be submitted by August 1, 2026, and the first required test must be completed by August 1, 2027.

Classes B and C remain exempt from periodic source testing requirements under the amended rule.

Leak Detection and Repair (LDAR) & Optical Gas Imaging (OGI)

Compliance monitoring under Amended Rule 462 introduces the adoption of Optical Gas Imaging (OGI) as a required monitoring method for most facilities. Currently, owners and operators of any facility, regardless of class, are required to perform leak inspections either via: (1) monthly sight, sound, and smell, or (2) quarterly organic vapor analyzer (OVA) leak detection in accordance with EPA Method 21. Any leaks are required to be repaired within seventy-two (72) hours, or three (3) calendar days.

Now, with the exception of Class C facilities, owners and operators are required to conduct monthly OGI inspections in addition to the current leak checks and periodic instrument monitoring. Thus, OGI is an added inspection layer, not a leak detection method replacement, and will start as early as August 1, 2026. Components that are to be inspected with OGI include:

• All the components of the liquid loading line between any storage tanks,
• The liquid pump and the transporting vessel,
• The vapor return line from the transporting vessel to the storage tank, and
• The vapor recovery system and/or vapor disposal system.

OGI is qualitative rather than quantitative, and is thus subject to temperature, distance, gas composition, and operator techniques. Thus, “visible vapors” are subjective in nature but need consistent criteria in order to flag what is an official plume versus a one-off OGI-camera shimmer. As defined by the Draft Rule Language (7/1/2025):

VISIBLE VAPORS are any VOC vapors detected with an OGI Device, when operated and maintained in accordance with manufacturer training or certification, or equivalent CARB training, user manuals, specifications, and recommendations. Visible Vapors do not include liquid spillage or condensate resulting from Liquid Leaks.

Thus, under PAR 462, any visible vapor under OGI is therefore a leak and is subject to leak repair requirements. Through utilizing OGI, facilities can now scan entire loading systems from a distance in minutes and visualize vapor plumes that Method 21 can often miss, or leaks that humans cannot see, smell, or hear.

Lastly, a new subdivision is added to PAR 462 in the event that the U.S. EPA declares that the Coachella Valley area has failed to meet an ozone attainment deadline. Subdivision (i) of PAR 462 imposes an Ozone Contingency Measure, which increases OGI frequency from monthly inspections to inspections every two (2) weeks. As it relates to PAR 462, the main ozone attainment deadline of concern is the Coachella Valley area 2008 Ozone NAAQS, with a deadline of July 20, 2027. If the Coachella Valley area has not been attained, then the biweekly OGI requirement would start sixty (60) days after EPA issues a failure-to-attain finding. As of the current draft Staff Report and draft Rule Language, there is no provision that provides a timeline for when the contingency ends.

Title V Permit Modifications

In light of these amendments, of the estimated fifty-three (53) facilities subject to Rule 462, twenty (20) of the Class A sites are Title V major sources. Although SCAQMD does not anticipate control-device upgrades since 5 mg/L is already achieved in practice, permit updates are required regardless. Even without new installations or retrofits, Title V permits must still be modified to add the new VOC limits, OGI monitoring conditions, and associated recordkeeping.

Title V permits must include the new 5 mg/L (0.04 lb/1,000 gal) limit and the associated 60-month source test requirement, including conditions for the source test protocol, notice, and report timelines. OGI-based leak detection must be added in addition to the current provisions for instrument detection via Method 21 and for sight, smell, and sound inspections. Leak repair provisions are to be updated, including the five (5) year recordkeeping requirement. Additionally, Semiannual Monitoring and Annual Certifications may need to reflect OGI counts and schedules. Lastly, new Continuous Monitoring System (CMS) Plans may need to be submitted and approved, or existing ones may need to be modified in order to prescribe a longer averaging time to minimize potential shutdowns due to the reduced VOC limit of 0.04 lbs per 1000 gallons.

Closing Thoughts

Amended Rule 462 aims to be more of a performance and accountability amendment, and less of an equipment-upgrade mandate. The existing VOC limit for Class A facilities is cut in half in order to formalize what many terminals can already achieve in practice, and monthly OGI inspections push facilities to find and fix releases that current leak detection methods miss. An added administrative burden is added for Title V facilities, with the requirement to modify Title V permits to add the new rule provisions, with costs stemming more from the permit modifications and added LDAR operations than from installing new control devices. In short, facilities will need to shift focus towards permitting updates and LDAR procedures as the August 1, 2026 deadline continues to approach, and should be ready in the event the ozone contingency measure triggers biweekly inspections.

If you have any questions regarding the PAR or require assistance with air permitting, please contact Trinity’s Irvine office at 949.567.9880.