Petroleum refineries in the South Coast Air Quality Management District operate under the densest layer of emissions testing requirements in the country. Between Rule 1109.1 BARCT deadlines, the RECLAIM-to-command-and-control transition, fenceline monitoring under AB 1647, and ongoing CEMS/RATA obligations, the testing calendar for a single refinery can run into hundreds of individual events per year.
This guide breaks down what refinery EHS managers and compliance officers need to track right now — and what's coming next.
Rule 1109.1: BARCT Requirements for Petroleum Refineries
Rule 1109.1 implements AB 617's Best Available Retrofit Control Technology mandate specifically for petroleum refinery equipment. It targets NOx, CO, SOx, PM, and VOC emissions from boilers, heaters, FCCU regenerators, SRU/TGU systems, coke calcining operations, and other combustion sources at refineries.
The rule establishes phased compliance deadlines. Larger equipment — heaters and boilers rated above 40 MMBtu/hr — faces earlier deadlines, while smaller units have staggered timelines extending through 2031. Each compliance phase requires source testing to demonstrate that installed controls actually achieve the required emission limits.
What makes 1109.1 particularly demanding is that it applies unit-by-unit. A refinery with 50 heaters and boilers doesn't get a plantwide cap. Each unit must individually demonstrate compliance through reference method testing.
The RECLAIM Transition and Its Testing Impact
When SCAQMD dismantled RECLAIM for NOx and SOx, refineries shifted from a market-based cap-and-trade system to traditional command-and-control permitting. Under RECLAIM, a facility could buy credits to cover higher-emitting units. That flexibility is gone.
Every individual emission unit now requires its own permit condition and its own source testing to verify compliance. For a typical refinery, this means the number of required source tests can triple or quadruple compared to the RECLAIM era.
The transition also exposed units that had operated without tight emission limits for years. Some equipment that was "covered" by excess RECLAIM Trading Credits now needs retrofit controls — and testing to prove those controls work.
Facilities that haven't restructured their testing programs to match the new unit-by-unit requirements are at significant risk of Notices of Violation.
CEMS Requirements Under Rules 218.2 and 218.3
Most refinery combustion sources above a certain size are required to operate CEMS for NOx, CO, and in many cases O2. Rules 218.2 (general provisions) and 218.3 (performance specifications) govern the installation, operation, calibration, and certification of those systems.
The key testing requirement is the RATA — Relative Accuracy Test Audit — performed every four calendar quarters. During a RATA, a LAP-approved source testing company runs reference method measurements simultaneously with the CEMS readings and compares the results. If the relative accuracy falls outside allowable limits, the CEMS loses its certification.
A failed RATA isn't just a paperwork problem. The facility must revert to periodic source testing at increased frequency until the CEMS is re-certified. For a refinery running dozens of monitored units, one failed RATA cascades into scheduling headaches and increased costs.
Between RATAs, quarterly Cylinder Gas Audits (CGAs) verify analyzer accuracy. DAS (Data Acquisition System) verification, daily calibration drift checks, and routine maintenance round out the ongoing CEMS obligations.
Pollutants Tested at Refineries
Refineries emit a broader range of regulated pollutants than almost any other facility type. A typical refinery testing program covers:
Criteria Pollutants
- NOx — Primary concern from combustion sources. Tested via SCAQMD Method 100.1.
- CO — Combustion efficiency indicator. SCAQMD Method 100.1.
- SO2 — From sulfur recovery units, FCCU regenerators, and fuel gas combustion. SCAQMD Method 100.1 or SCAQMD Method 6.1.
- PM/PM10/PM2.5 — Particulate from FCCUs, coke calciners, and combustion equipment. SCAQMD Methods 5.1-5.3, EPA Method 5, or Method 201A.
- VOC — Fugitive and process emissions. SCAQMD Methods 25.1/25.3, EPA Method 25A, or Method 1.
Toxic Air Contaminants
- H2S — Monitored continuously in fuel gas systems. Source tested at SRU tail gas and flare headers.
- Metals — Nickel, vanadium, and other metals from FCCU catalyst attrition. CARB Method 436.
- Benzene — Particularly from wastewater treatment and storage operations. Method 18 or TO-15.
- PAHs, formaldehyde, HCl — Depending on process units and fuel types.
AB 2588 Air Toxics Hot Spots requirements add another layer. Refineries are typically prioritized for health risk assessments, meaning emissions data accuracy directly affects risk calculations and potential control requirements.
What Makes Refinery Testing Unique
Multiple Concurrent Units
A refinery isn't one source. It's 50 to 200+ individual emission units spread across a complex of process units, tank farms, loading racks, and wastewater systems. Coordinating source testing across that many units — each with different access requirements, process conditions, and scheduling constraints — demands careful logistical planning.
FCCU Testing
Fluid Catalytic Cracking Unit testing is among the most complex source testing performed anywhere. FCCU regenerator stacks carry high temperatures, heavy particulate loading, and a mix of pollutants including PM, SOx, NOx, CO, metals, and organics. Method 5 runs at an FCCU can take 8+ hours per run, and three runs are typically required.
The test crew needs to work at elevation in a hot, confined environment with specialized equipment. Errors in isokinetic sampling or probe positioning can invalidate an entire test day.
Flare Monitoring
SCAQMD Rule 1118 requires refineries to monitor and minimize flaring events. While flares aren't source-tested in the traditional sense, compliance involves continuous flow monitoring, composition analysis, and emission calculations. Testing the monitoring systems themselves — verifying flow meter accuracy, gas chromatograph calibration — falls into the source testing scope.
Storage Tank Testing
Rule 1178 and federal MACT standards require emission assessments for storage tanks containing VOC-emitting materials. Floating roof tanks need seal gap measurements and fitting inspections. Fixed roof tanks with controls require outlet testing to verify destruction efficiency.
High-Stakes Compliance Environment
Refineries operate under Consent Decrees, Title V permits, SCAQMD rules, CARB regulations, and EPA MACT/NSPS standards simultaneously. A single missed test or failed result can trigger enforcement from multiple agencies. The tolerance for errors is essentially zero.
AB 1647 Fenceline Monitoring
AB 1647 requires petroleum refineries in California to install and operate fenceline air monitoring systems. The January 2026 deadline has passed, meaning systems should now be operational and reporting data.
Fenceline monitoring measures ambient concentrations of specified pollutants at the refinery boundary. While this is distinct from stack source testing, the two programs interact. When fenceline monitors detect elevated readings, the first question regulators ask is whether emission units are operating within their permitted limits — which source test data answers.
Facilities that can demonstrate current, passing source test results across their units are in a stronger position when fenceline data triggers inquiries.
Testing Frequency and Scheduling
Refinery testing programs operate on overlapping cycles:
- RATA testing — Every 4 calendar quarters for each CEMS-equipped unit.
- Permit-required source testing — Typically annual or biennial per unit, as specified in individual permit conditions.
- Rule 1109.1 compliance demonstrations — At initial compliance and as specified by SCAQMD.
- MACT/NSPS testing — Per federal requirements, often biennial.
- AB 2588 updates — Quadrennial or as directed by the district.
- Startup/shutdown testing — After turnarounds or process modifications.
For a mid-size refinery, this can mean 100+ individual source tests per year. Scheduling becomes a project management exercise — coordinating with process operations, turnaround schedules, weather windows, and testing crew availability.
Our Refinery Testing Experience
Accurate Environmental Services has performed emissions testing at Southern California refineries for over three decades. Our refinery client history includes ExxonMobil Torrance, Ultramar (now Valero Wilmington), ARCO Los Angeles (now Marathon), and Marathon Carson.
We maintain LAP approval for all reference methods required in refinery testing — SCAQMD Methods 1.1-4.1, 5.1-5.3, 6.1, 100.1, 207.1, 307.91, and others. Our crews are trained and badged for refinery access, familiar with hot work permits, confined space entry, and refinery-specific safety requirements.
We handle RATA testing, Rule 1109.1 compliance demonstrations, FCCU particulate and metals testing, SRU/TGU testing, and AB 2588 toxic emissions quantification.
Planning Your Testing Program
Refinery compliance testing isn't something you schedule one test at a time. It requires a structured annual program that accounts for every unit, every applicable rule, every RATA cycle, and every permit condition.
Start with a master testing calendar. Map every unit against its permit conditions, applicable rules, and CEMS certification cycle. Identify conflicts with planned turnarounds. Build in contingency time for weather delays, process upsets, and retest needs.
The cost of reactive testing — scrambling after a Notice of Violation or failed RATA — far exceeds the cost of a planned program.
Frequently Asked Questions
Frequency varies by unit, permit condition, and applicable rule. CEMS-equipped units require RATA testing every four calendar quarters. Non-CEMS units typically require annual or biennial source testing per permit conditions. Rule 1109.1 compliance demonstrations are required at initial compliance deadlines and per SCAQMD direction. Most refineries run 100+ individual tests per year across all units.
The CEMS for that unit loses its certification. The facility must revert to periodic reference method source testing — typically quarterly — until the CEMS is repaired, recalibrated, and passes a new RATA. During the uncertified period, the facility may also face increased scrutiny from SCAQMD inspectors and potential enforcement action if emissions data gaps occur.
No. Fenceline monitoring and stack source testing serve different purposes. Fenceline monitoring measures ambient pollutant concentrations at the facility boundary. Stack testing measures emissions directly from individual units to verify permit compliance. Both are required. However, strong source testing records support a refinery's position when fenceline data triggers regulatory inquiries.
Under RECLAIM, refineries operated under a facility-wide emissions cap and could use trading credits to cover higher-emitting units. After the transition to command-and-control, each individual unit must have its own permit limits and demonstrate compliance through unit-specific source testing. This has significantly increased the total number of required tests at most refineries — in many cases tripling or quadrupling the pre-transition testing workload.
Accurate Environmental Services has performed emissions testing at Southern California refineries for over three decades. We handle RATA testing, Rule 1109.1 compliance demonstrations, FCCU testing, and AB 2588 toxic emissions quantification.
Call (714) 379-9200, email wallymoe@accuenviro.com, or request a quote at accuenviro.com