CEMS-CGA, RATA & Certification in California: 2026 Compliance Guide for Industrial Facilities
Is your Continuous Emissions Monitoring System actually producing data that regulators can rely on?
For many industrial facilities in California, having a CEMS (Continuous Emissions Monitoring System) installed is only the beginning. Depending on the applicable permit, air-district rules, and federal requirements, the system may need initial certification, quality assurance testing, Cylinder Gas Audits (CGA), Relative Accuracy Test Audits (RATA), ongoing QA/QC and periodic reporting.
For facilities regulated by the South Coast Air Quality Management District (South Coast AQMD), Rules 218, 218.2 and 218.3 establish important requirements for CEMS administration, certification, performance specifications and QA/QC. South Coast AQMD’s current rule book lists Rule 218 as amended March 5, 2021, and Rules 218.2 and 218.3 as amended September 2, 2022.
This makes professional CEMS Certification, CGA and RATA testing an important part of an industrial facility’s compliance strategy.
CEMS Certification California
What Is CEMS?
CEMS stands for Continuous Emission Monitoring System.
A CEMS continuously measures one or more emission parameters from an industrial source.
Depending on the application, it can monitor:
NOx
SO₂
CO
CO₂
Oxygen (O₂)
Flow rate
Moisture
Other regulated pollutants
A CEMS can continuously generate emissions data that may be used for compliance demonstrations, reporting and regulatory decision-making.
South Coast AQMD explains that CEMS can be required to continuously demonstrate compliance with permitted concentration limits and, for applicable RECLAIM systems, automatically report mass emissions.
The key point:
A CEMS is not automatically a compliance instrument simply because it is installed.
It must meet the applicable certification and performance requirements.
What Are CEMS Certification, RATA and CGA?
These three terms are closely connected but have different purposes.
CEMS Certification
Demonstrates that the monitoring system meets applicable regulatory performance and quality requirements and can function as an official data-reporting instrument.
RATA — Relative Accuracy Test Audit
Compares CEMS measurements against an applicable reference method to determine whether the CEMS is sufficiently accurate.
CGA — Cylinder Gas Audit
Challenges the CEMS with certified calibration/audit gases to verify analyzer response and measurement performance.
Together, they help answer:
Can regulators trust the emissions data being produced by the CEMS?
Why Is CEMS Compliance Important in California?
Industrial facilities may have strict emission limits for pollutants such as NOx, SO₂ and other contaminants.
When CEMS data are used to demonstrate compliance, inaccurate monitoring can create a serious problem.
A facility may believe it is compliant while the monitoring system is:
Drifting
Out of calibration
Producing invalid data
Experiencing excessive downtime
Outside required performance specifications
Operating outside its approved span range
Missing required QA/QC tests
South Coast AQMD Rule 218.3 provides requirements addressing CEMS performance, QA/QC, out-of-control periods and alternative data acquisition.
2026 California CEMS Regulatory Landscape
California’s CEMS requirements continue to evolve through local air-district rules, federal requirements and pollutant-specific monitoring programs.
For South Coast AQMD-regulated facilities, Rules 218, 218.2 and 218.3 remain central to CEMS requirements.
South Coast AQMD’s FY 2026–27 budget and objectives also continue to identify CEMS Certification as a compliance activity, demonstrating that CEMS review and certification remain an active regulatory function.
2026 takeaway:
CEMS should be treated as an ongoing compliance program—not a one-time installation project.
CEMS Certification: What Does the Process Involve?
For a new or modified CEMS, certification can involve multiple stages.
South Coast AQMD’s current CEMS application package describes a certification pathway that includes:
CEMS plan, where applicable
CEMS application
Quality Assurance Plan (QAP)
Initial District approval
Certification source-test protocol
District review/approval of the protocol
Certification source testing
Certification source-test report
District approval/final certification
Continuing QA/QC and periodic testing
Once certified, the CEMS remains subject to requirements involving maintenance, modifications, outages, records and periodic QA/QC testing such as RATAs.
This is why certification should be planned early.
A facility should not wait until the CEMS installation is complete before considering the certification process.
RATA Testing Company
What Is a RATA?
RATA = Relative Accuracy Test Audit.
A RATA evaluates how closely the CEMS measurement agrees with an applicable reference method.
In simple terms:
CEMS Result vs. Reference Method Result
The closer they agree, the more confidence regulators can have in the CEMS data.
South Coast AQMD defines relative accuracy in terms of the difference between CEMS-generated data and reference-method results, including the confidence coefficient.
A typical RATA may involve:
CEMS operating
↓
Reference-method sampling
↓
Simultaneous measurements
↓
Multiple test runs
↓
Statistical evaluation
↓
Relative accuracy calculation
↓
Pass / Fail determination
Why Is RATA Testing So Important?
Imagine your CEMS reports:
NOx = 45 ppm
But an approved reference method produces significantly different results.
Which number should regulators trust?
That’s exactly why RATA exists.
A successful RATA provides evidence that the CEMS is accurately measuring the emissions parameter within the applicable performance specification.
South Coast AQMD provides dedicated technical guidance for RATA-related issues, including RATA outliers and mass-emissions RATA for non-concurrent concentration and flow measurements.
What Is a CGA?
CGA = Cylinder Gas Audit.
During a CGA, the CEMS is challenged using gases with known certified concentrations.
Under federal EPA QA procedures, applicable CGA testing uses a zero-level gas and two upscale audit levels within specified ranges, with repeated injections designed to challenge the measurement system.
The basic concept is:
Known Gas → CEMS → Measured Value → Compare
If the CEMS response is outside the applicable tolerance, corrective action may be required.
RATA vs. CGA
Feature
RATA
CGA
Full Name
Relative Accuracy Test Audit
Cylinder Gas Audit
Main Purpose
Compare CEMS against reference method
Check analyzer response using known gases
Reference Method
Yes
No, uses certified gases
Field Sampling
Usually required
Gas challenge
Statistical Evaluation
Yes
Yes, according to applicable procedure
Frequency
Depends on applicable rule/program
Depends on applicable rule/program
Certification Role
Important
Important QA/QC component
Failure Response
Investigation/correction/retest as required
Calibration/correction/retest as required
Important:
Don’t assume that a CGA replaces a RATA in every regulatory program.
The applicable rule, permit and federal/state monitoring requirements determine what is required.
How Often Is RATA Required?
There is no single testing frequency for every California CEMS.
The interval depends on the applicable program.
For example, EPA’s Procedure 1 for applicable gas CEMS requires a RATA at least once every four calendar quarters, subject to the applicable provisions. It also provides for CGA-based quarterly QA in certain circumstances.
Other programs can have different requirements.
Your facility’s permit and applicable regulation control.
This is especially important for facilities operating under:
Title V
South Coast AQMD rules
RECLAIM-related requirements
Federal NSPS requirements
Federal NESHAP/MACT requirements
40 CFR Part 60
40 CFR Part 75
Pollutant-specific monitoring programs
RATA Certification
What Happens When a CEMS Fails QA/QC?
This is where CEMS compliance becomes particularly important.
A failed QA/QC test can result in an out-of-control period under applicable requirements.
South Coast AQMD Rule 218.3 provides that CEMS data generated during an applicable out-of-control period can be considered invalid for emission quantification in a compliance demonstration.
The facility may then need to:
Identify the problem
Correct the CEMS
Perform the required QA/QC test
Establish when valid data resumes
Evaluate affected data
Use an approved alternative data-acquisition method where applicable
Complete required reporting
This can become expensive if the issue is discovered too late.
Common Reasons CEMS Fail RATA or QA/QC
1. Analyzer Calibration Problems
Incorrect calibration can create measurement bias.
2. Sampling-System Problems
Leaks, condensation, contamination or sample-line problems can affect readings.
3. Span Range Problems
The selected span must be appropriate for the applicable requirements.
4. Moisture Interference
Moisture can affect certain monitoring systems if not properly accounted for.
5. Stratification
Non-uniform pollutant concentrations across the stack can affect comparison between the CEMS and reference method.
6. Flow Issues
Poor flow measurement can affect mass-emission calculations.
7. Aging Components
Sensors, analyzers, pumps and other components can degrade over time.
8. Poor Maintenance
A CEMS requires continuous attention.
CEMS Certification Is Not “Set It and Forget It”
A common mistake is:
Install CEMS → Get certified → Forget about it.
That’s not how an effective compliance program works.
After certification, facilities must continue managing:
Calibration + QA/QC + RATA + CGA + Maintenance + Data Availability + Records + Reporting
South Coast AQMD’s certification materials specifically state that certified CEMS remain subject to scheduled and unscheduled maintenance, outages, modifications, records/reporting and ongoing QA/QC.
2026 Update: CEMS Technology Is Expanding
CEMS requirements are also evolving for specialized pollutants.
A notable example is ethylene oxide (EtO).
South Coast AQMD entered into a July 2025 Memorandum of Understanding with Parter to help develop performance specifications, verification test protocols and implementation guidance for an EtO CEMS certification program. The MOU runs through December 31, 2026 unless extended.
This demonstrates an important industry trend:
Continuous monitoring is expanding beyond traditional NOx/SO₂ applications.
Facilities with specialized toxic-air-contaminant requirements should monitor regulatory developments closely.
CEMS and Environmental Compliance Are Becoming More Data-Driven
Modern air-quality compliance increasingly depends on continuous data.
Instead of relying only on periodic stack tests, regulators can use monitoring systems to evaluate:
Hourly emissions
Daily emissions
Operating conditions
Exceedances
Data availability
Control-device performance
Long-term trends
South Coast AQMD’s CEMS application materials state that applicable CEMS can continuously monitor compliance and automatically signal exceedances, breakdowns and out-of-control periods.
Accurate data is therefore a compliance asset.
Pros of CEMS, RATA, CGA & Certification
✅ 1. Continuous Compliance Visibility
CEMS provides ongoing emissions information rather than occasional snapshots.
✅ 2. Early Problem Detection
Abnormal emissions can potentially be identified faster.
✅ 3. Stronger Compliance Documentation
Certified monitoring data can support regulatory reporting where applicable.
✅ 4. Better Process Control
Operators can use emissions information to improve process operation.
✅ 5. Reduced Compliance Uncertainty
Routine QA/QC helps identify monitoring problems before they become major issues.
✅ 6. Better Long-Term Data
Historical CEMS information can help identify trends.
RATA Testing, Cylinder Gas Audit
Challenges / Cons
❌ Higher Initial Cost
Installing a compliant CEMS can require significant capital investment.
❌ Ongoing Maintenance
Analyzers, sampling systems and data-acquisition equipment require regular attention.
❌ QA/QC Requirements
RATA, CGA and other tests require planning and qualified personnel.
❌ Data Availability Issues
CEMS downtime can create compliance complications.
❌ Technical Complexity
CEMS involve instrumentation, electronics, sampling systems, software and regulatory requirements.
❌ Regulatory Changes
Changes to rules or permits can require modifications to the monitoring program.
But the cost of maintaining a reliable CEMS is usually easier to manage than discovering a monitoring failure during a compliance deadline.
Which Industries May Need CEMS Services?
Potential applications include:
Power & Energy
Power plants
Cogeneration facilities
Distributed generation
Manufacturing
Chemical plants
Metal processing
Cement
Glass
Manufacturing facilities
Petroleum & Chemical
Refineries
Petrochemical plants
Process facilities
Waste & Combustion
Waste-to-energy
Incineration
Thermal processing
Industrial Boilers
Large boilers
Steam generators
Process heaters
Other Regulated Sources
Facilities with permit or regulatory requirements for continuous monitoring.
EES can help bring these pieces together into one coordinated compliance program.
South Coast AQMD maintains a Laboratory Approval Program (LAP) under which laboratories and source-testing firms are evaluated method-by-method for personnel, equipment, documentation, QA and other criteria. Facilities should verify that the testing provider and applicable methods meet the requirements of their specific program.
Rule 1147.2 in California 2026: Latest Updates, Pros, Cons & How EES Helps Industries
Rule 1147.2 — NOx Reductions from Metal Melting and Heating Furnaces is a key South Coast AQMD regulation for facilities operating permitted metal melting, metal heat-treating, metal heating, and metal forging furnaces.
A critical clarification before discussing 2026: Rule 1147.2 is not a statewide California regulation. It is a South Coast AQMD rule applicable within the District’s jurisdiction when the equipment meets the rule’s applicability requirements. The current official rule is identified as Rule 1147.2, adopted April 1, 2022.
As of August 2026, the official South Coast AQMD material reviewed does not show a newly adopted 2026 amendment replacing Rule 1147.2. However, 2026 remains important because South Coast AQMD has an active rulemaking agenda with more than two dozen planned amendments/adoptions across its regulatory program, while the agency continues implementing measures aimed at reducing emissions and improving air quality.
For metal-processing facilities, the practical question is therefore not simply, “Was Rule 1147.2 changed in 2026?” It is:
“Is my furnace currently meeting the applicable Rule 1147.2 limits, testing schedule, permit conditions and monitoring requirements?”
That’s where professional source testing and compliance support become valuable.
Energy Environmental Solutions, Inc. (EES) can help industries with Rule 1147.2 source testing, NOx testing, CO testing, compliance test protocol development, CEMS, RATA, CGA, engineering studies, emissions monitoring and regulatory reporting.
What Is Rule 1147.2?
Rule 1147.2 was created specifically to reduce nitrogen oxide (NOx) and carbon monoxide (CO) emissions from four major categories of combustion equipment:
Metal melting furnaces
Metal heat-treating furnaces
Metal heating furnaces
Metal forging furnaces
The rule applies to an owner or operator of one of these furnaces when the equipment requires a South Coast AQMD permit.
The regulation was developed as part of South Coast AQMD’s broader transition away from the RECLAIM program toward more source-specific emissions controls. South Coast AQMD documents describe Rule 1147.2 as moving metal melting and heating furnace operations from Rule 1147 into a dedicated rule with NOx limits reflecting current BARCT — Best Available Retrofit Control Technology.
That makes Rule 1147.2 particularly relevant to businesses in the metal-processing sector.
Why Does Rule 1147.2 Matter in 2026?
NOx is a major precursor to ozone and particulate pollution. In Southern California, reducing stationary-source NOx remains an important component of regional air-quality planning.
South Coast AQMD’s 2026 outlook identifies extensive rulemaking activity intended to implement the 2016 and 2022 Air Quality Management Plans and the 2024 PM Plan, reduce health risks, and support attainment of state and federal air-quality standards.
That means industrial facilities shouldn’t treat Rule 1147.2 as an old compliance document sitting in a filing cabinet.
And 2026 is especially relevant for facilities managing multiple furnaces because some of the rule’s multi-unit implementation schedule reaches 100% compliance milestones in 2026 and beyond.
Latest Rule 1147.2 Updates for 2026
1. The Current Adopted Rule Is Still the April 1, 2022 Rule
The official South Coast AQMD rulebook identifies Rule 1147.2 as:
Rule 1147.2 — NOx Reductions from Metal Melting and Heating Furnaces Adopted: April 1, 2022
The current official rule remains the primary document facilities should use when evaluating compliance in 2026.
There is an important distinction between current regulatory obligations and future rulemaking activity.
A facility shouldn’t assume that every item appearing on a proposed-rule page is already law.
2. 2026 Is an Important Milestone for Multiple-Furnace Facilities
One of the most relevant provisions for 2026 is the multiple-unit implementation schedule.
For facilities with two or more applicable units, Rule 1147.2 provides a phased approach based on the percentage of total rated heat-input capacity represented by units covered by the implementation schedule.
The rule specifies a January 1, 2026 milestone requiring:
100% of applicable rated heat-input capacity for facilities with 2–9 units
67% for facilities with 10–19 units
The schedule continues to January 1, 2028, when 100% applies to the 20-or-more-unit category under the specified schedule.
Why is this important?
A company operating one furnace may have a relatively straightforward compliance program.
A company operating 10, 15 or 20 furnaces has a much more complicated compliance calendar.
For those facilities, 2026 is not simply another year on the calendar—it can represent a significant implementation milestone.
3. Rule 1147.2 Has Different Limits for Different Furnaces
One of the biggest mistakes a facility can make is assuming there is one universal NOx limit for every furnace.
There isn’t.
For existing units below 40 MMBtu/hr, Table 1 establishes different NOx limits depending on furnace type and operating temperature.
Existing Furnace
NOx Limit
CO Limit
Metal Melting
40 ppm
1,000 ppm
Metal Heat Treating / Heating / Forging ≤1,200°F
40 ppm
—
Metal Heat Treating / Heating / Forging >1,200°F
50 ppm
—
Radiant-Tube Burners
50 ppm
—
Units ≥40 MMBtu/hr
15 ppm
—
The applicable ppm limits are corrected to 3% oxygen on a dry basis, with an 8-hour rolling average applying where specified for units equipped with certified NOx CEMS.
That means compliance testing has to be designed around the actual furnace configuration.
4. New Units Face Different Requirements
Rule 1147.2 also establishes a separate Table 3 for new units.
For example:
Metal melting furnaces below 40 MMBtu/hr: 40 ppm NOx
Metal heat treating/heating/forging ≤1,200°F: 30 ppm NOx
Metal heat treating/heating/forging >1,200°F: 40 ppm NOx
Radiant-tube burners: 40 ppm NOx
Units ≥40 MMBtu/hr: 15 ppm NOx
The rule specifies the applicable oxygen correction and averaging provisions.
This is an important consideration when a facility is replacing an old furnace.
Replacing equipment does not necessarily mean you can simply carry the old compliance assumptions into the new installation.
5. Burner Age Can Affect Implementation
For certain units below 40 MMBtu/hr, Rule 1147.2 uses burner age as part of its implementation schedule.
For applicable existing units, facilities need to determine burner age using documentation such as:
Burner manufacturer invoices
Previous permit applications
Manufacturer identification/rating plates
Other substantiated written information approved by the Executive Officer
Where burner age cannot be determined through the specified methods, the rule provides a default treatment.
This makes equipment records extremely important.
Think of burner documentation as part of your compliance evidence.
If you don’t know when the burner was installed, you may have difficulty determining which implementation pathway applies.
6. Source Testing Is a Core Requirement
Rule 1147.2 contains specific source-testing requirements.
For units subject to the applicable concentration limits:
Units below 10 MMBtu/hr
A source test is required no later than 60 calendar months from the previous source test.
Units ≥10 MMBtu/hr
The testing interval depends on annual heat input:
≤23 billion Btu/year: up to 60 months
>23 billion Btu/year: up to 36 months
These requirements are based on the rule’s specified testing provisions.
This means the test frequency isn’t necessarily determined by furnace size alone.
Annual heat input can matter.
7. New Furnaces Have an Initial Testing Requirement
For new units, Rule 1147.2 requires an initial source test no later than 18 months after the Permit to Construct is issued, unless the Executive Officer approves an extension in writing.
For existing units, the rule establishes its own initial testing provisions and allows certain previously conducted South Coast AQMD-approved source tests to be used when the specified conditions are satisfied.
This creates an important project-management requirement:
Environmental compliance should be included in the equipment installation schedule from the beginning.
Don’t wait until the furnace is commissioned and production is underway to start thinking about source testing.
8. A Test Protocol Must Be Submitted Before Testing
Rule 1147.2 requires the source-test protocol to be submitted to the Executive Officer for approval at least 90 days before the scheduled source test.
The rule also specifies when the actual test must occur relative to protocol approval.
This is one of the strongest reasons to work with an experienced source-testing company.
A compliance test is not simply:
“Bring the analyzer → measure emissions → issue a report.”
Rule 1147.2 specifies approved source-testing procedures, including applicable South Coast AQMD methods and EPA Method 19, with alternative methods requiring the appropriate advance approvals.
The rule specifically references methods including:
South Coast AQMD Method 100.1
South Coast AQMD Method 7.1
South Coast AQMD Method 10.1
EPA Method 19
It also requires compliance source testing to use a South Coast AQMD-approved contractor under the Laboratory Approval Program for the applicable procedures.
That makes contractor selection a compliance issue—not merely a purchasing decision.
10. Source-Test Reports Have a 60-Day Deadline
After testing, Rule 1147.2 requires source-test reports to be submitted to the Executive Officer within 60 days of completion of the source test.
This creates three separate deadlines that facility managers should track:
Protocol submission → Test date → Report submission
A facility can conduct a technically successful test and still create a compliance problem if the required documentation isn’t handled correctly.
11. Large Furnaces May Require CEMS
For units with a rated heat-input capacity of 40 MMBtu/hr or greater, Rule 1147.2 includes CEMS requirements for measuring NOx and oxygen under specified facility circumstances.
The rule references applicable requirements under South Coast AQMD Rules 218.2 and 218.3, and Rule 2012 for certain RECLAIM facilities.
This means large-furnace compliance may involve much more than periodic stack testing.
Facilities may need to manage:
CEMS → Certification → QA/QC → RATA → Monitoring → Data validation
That is where specialized environmental testing expertise becomes especially valuable.
Pros of Rule 1147.2
1. Lower NOx Emissions
The primary benefit is reduced NOx emissions from metal-processing furnaces.
Lower NOx supports regional efforts to improve ozone and particulate pollution.
2. Better Combustion Performance
Testing can identify combustion problems involving:
Burner settings
Air/fuel ratio
Excess oxygen
Burner deterioration
Furnace operation
Control systems
3. More Transparent Compliance
Measured emissions data provide a stronger compliance record than relying solely on theoretical calculations.
4. Encourages Cleaner Technology
The regulation can encourage facilities to consider:
Low-NOx burners
Improved combustion controls
Burner modernization
Better monitoring
Furnace upgrades
5. Supports Long-Term Planning
A structured testing program gives facility managers better information about equipment performance.
6. Helps Reduce Community Exposure
Metal-processing facilities can be located near industrial communities. Reducing combustion-related pollutants can support broader air-quality objectives.
Cons and Challenges of Rule 1147.2
1. Testing Costs
Professional source testing requires specialized personnel, equipment, calibration, field measurements, data analysis and reporting.
2. Production Disruption
Testing must be coordinated with furnace operations and production schedules.
3. Equipment Upgrades Can Be Expensive
Older burners may not easily achieve newer emission limits without modification or replacement.
4. Multiple Units Increase Compliance Complexity
Facilities with many furnaces may have different:
Burner ages
Heat-input ratings
Operating temperatures
Emission limits
Test frequencies
Permit conditions
5. CEMS Adds Another Layer
Large units may have continuing CEMS-related responsibilities involving certification, maintenance and performance testing.
6. Documentation Is Critical
Permit records, burner-age documentation, source-test reports and monitoring records need to remain organized.
What Industries Should Pay Attention to Rule 1147.2?
Potentially affected operations include facilities involved in:
Metal Casting
Foundries
Metal Forging
Heat Treating
Metal Heating
Aluminum Processing
Steel Processing
Iron Processing
Nonferrous Metal Manufacturing
Industrial Furnace Operations
Metal Fabrication
The exact applicability depends on the equipment and permit.
Rule 1147.2 Compliance: What Should a Facility Check?
A facility manager should review the following:
Is the furnace subject to Rule 1147.2?
What type of furnace is it?
What is its rated heat-input capacity?
What is the burner age?
What is the applicable NOx limit?
Does a CO limit apply?
Is the unit a new or existing unit?
Is the facility RECLAIM, former RECLAIM or non-RECLAIM?
When was the last source test?
When is the next test due?
Is the source-test protocol approved?
Is CEMS required?
Are RATA/CGA requirements applicable?
Are the required permits current?
Are source-test reports submitted on time?
Are records complete?
How EES Helps With Rule 1147.2 Compliance
Energy Environmental Solutions, Inc. (EES) provides environmental testing and engineering support to industrial facilities.
Rule 1147.2 Source Testing
EES can help facilities perform compliance source testing for applicable metal-processing furnaces.
NOx Testing
Accurate NOx measurement is fundamental to demonstrating compliance with Rule 1147.2.
CO Testing
Where applicable, EES can support CO emissions testing alongside NOx measurements.
For large furnaces subject to CEMS requirements, EES can support emissions monitoring programs.
RATA & CGA
EES can assist facilities with applicable Relative Accuracy Test Audits (RATA) and Cylinder Gas Audits (CGA).
Engineering Studies
EES can evaluate combustion performance and help facilities understand potential compliance strategies.
Regulatory Reporting
After testing, EES can assist with technical documentation and reporting.
Rule 1147.2 Testing Process
A professional compliance project can be organized into the following stages:
1. Permit Review
Review the current South Coast AQMD permit and equipment information.
2. Applicability Review
Determine exactly how Rule 1147.2 applies to the furnace.
3. Limit Identification
Determine the applicable NOx and CO limits.
4. Testing Schedule
Calculate when the next source test is due.
5. Protocol Development
Develop and submit the source-test protocol.
6. Field Testing
Conduct the required emissions measurements under appropriate operating conditions.
7. QA/QC
Review calibration, sampling and analytical data.
8. Emissions Calculations
Calculate concentrations and applicable emission rates.
9. Reporting
Prepare and submit the source-test report.
10. Follow-Up
If results indicate noncompliance, evaluate appropriate corrective actions.
Why Proactive Rule 1147.2 Testing Is Important in 2026
South Coast AQMD’s 2026 regulatory agenda demonstrates that the District continues to actively develop and implement air-quality controls. The agency says its 2026 rule calendar contains more than two dozen planned rule amendments and adoptions aimed at implementing air-quality plans, reducing health risks and improving compliance clarity.
That doesn’t mean Rule 1147.2 itself was amended in 2026.
It means the regulatory environment surrounding industrial emissions continues to evolve.
A facility that waits until an inspection, permit renewal or failed test to examine its furnace emissions may have fewer options than a facility that monitors performance proactively.
Rule 1147.2: 2026 Pros vs. Cons
Pros
Cons
Reduces NOx emissions
Source testing costs
Supports cleaner air
Production scheduling challenges
Encourages modern burners
Potential equipment upgrades
Provides measurable compliance data
Complex requirements for multiple furnaces
Helps identify combustion problems
CEMS obligations for certain large units
Improves regulatory readiness
Detailed documentation required
Supports long-term environmental planning
Testing must follow approved methods
The 2026 Takeaway
Rule 1147.2 remains an important compliance requirement for applicable metal-processing furnaces in the South Coast AQMD jurisdiction.
The current adopted rule dates to April 1, 2022, and the official material reviewed does not show a replacement 2026 amendment. At the same time, 2026 includes important implementation and regulatory-planning milestones, particularly for facilities with multiple furnaces.
For facility managers, the smartest approach is not to wait for a regulatory surprise.
Know your furnace. Know your burner age. Know your NOx limit. Know your testing frequency. Know your permit. Know your CEMS obligations.
And most importantly:
Know whether your emissions data can demonstrate compliance.
