Colorado’s oil and gas general permits for well production facilities have changed significantly with the release of General Permit 12 (GP12) on May 28, 2026. The prior framework under General Permit 09 (GP09) and General Permit 10 (GP10) established a standardized approach for permitting common equipment and emissions sources at well sites. GP12 builds on that structure and introduces a permitting framework aligned closely with updated Regulation 7 requirements.
Background: Colorado’s GP09 and GP10 Permitting Framework
Under GP09 and GP10, oil and gas operators would submit facility-wide emission limits under a single Well Production Facility Air Pollution Emission Notice (APEN) (Form APCD-216). Operators typically relied on emissions estimates supported by default emission factors and demonstrated compliance through periodic reporting and recordkeeping tied to those predefined assumptions. This allowed field operations to move efficiently under their own conservative assumptions and standardized factors; however, it also meant that compliance was tied primarily to estimations rather than site-specific data and operational performance. Furthermore, within 18 months of submittal, the GP09 and GP10 authorization would expire forcing operators to transition each piece of equipment from the facility-wide coverage to equipment-specific general permits and individual APENs.
Updates with the Colorado’s GP12
GP12 applies specifically to well production facilities and aligns with the latest Colorado air quality regulations. The permit covers storage tanks (oil, condensate, and produced water), hydrocarbon loadout operations, gas venting from separators, natural gas and diesel engines, fugitive emissions, and routine operational emissions such as venting, blowdowns, and pigging. These equipment types were each permitting under a source speficic general permit (GP01-11). GP12 moves to group everything under a single permit while updated regulatory definitions based on current Regulation 7 and identifies excluded facility types such as compressor stations and refineries. Dehydration units are not included under GP12, meaning operators would still need to complete the applicable construction permitting process before operating that equipment.
GP12 calls for each eligible piece of equipment at a facility to be permitted under GP12 through individual APENs (Form APCD Series 200), rather than having a single facility-wide APEN. It also removes the requirement to transition onto individual GPs within 18 months, and rather the only timelines to adhere to are the 5-year expiration of APEN’s.
The transition to GP12 introduces important timing considerations for operators. GP12 does not immediately invalidate existing GP09 or GP10 permits and facilities already permitted under GP09 or GP10 may continue operating under those permits. The cutoff day for acceptance of GP09 and GP10 will likely be July 15, 2026. After that, CDPHE will no longer accept new GP09 or GP10 applications. This creates a phased approach where both systems remain in use for a period, but new permitting efforts must align with GP12 moving forward after July 15, 2026.
Key changes with the GP12
One of the most notable changes under GP12 is the shift from facility-wide structure to equipment-specific emissions and process-based framework.
GP12 requires operators to track the operational parameters such as throughput, fuel use, and vented gas volumes. The result is a stronger connection between how facilities operate and how compliance is demonstrated. Tracking some of these parameters may help other Regulation 7 requirements such as the Annual Emissions Inventory Report (AEIR) or operator intensity requirements.
GP12 also places greater emphasis on site-specific data. Operators are expected to develop updated emission factors based on sampling and measurement rather than relying primarily on default values. This shift improves the reliability of emissions estimates and strengthens the defensibility of compliance demonstrations. In turn, it requires more robust data collection, quality control, and coordination between field teams and compliance personnel.
Previously operators who used general permits were forced to account for the maximum limit of the permit. For example, if an operator used a GP01 for condensate storage tanks this would consume 39 tons of volatile organic compounds (VOC), even if the potential to emit (PTE) was below this limit. Another common area that is over permitted is the GP07 for Hydrocarbon truck loading which include a 10 tons per year (tpy) limit of VOC. The GP12 will allow operators more tailored permitting limits specific to their equipment specific PTE significantly helping facilities close to title v permitting thresholds.
Emission factors and site-specific sampling will have to be developed periodically. Table 5 within the GP12 dictates the frequency. Sampling frequencies are dictated by attainment status and facility-wide emissions. If operators are still able to comply with the established limits, operators do not need to submit a new application to modify their GP12 registration.
| Area Classification | Facility-wide Permitted VOC Emissions | Sampling Frequency | Sampling Frequency for Storage Tanks with Actual Uncontrolled VOC Emissions ≥ 80 Tons per Year |
| Attainment | Less than 90 TPY | Every 5 years | Every 2 years |
| Attainment | Greater than or equal to 90 TPY | Annually | Annually |
| Marginal/Moderate Non-Attainment | Less than 90 TPY | Every 5 years | Every 2 years |
| Marginal/Moderate Non-Attainment | Greater than or equal to 90 TPY | Annually | Annually |
| Serious Non-Attainment | Less than 40 TPY | Every 5 years | Every 2 years |
| Serious Non-Attainment | Greater than or equal to 40 TPY | Annually | Annually |
| Severe Non-Attainment | Less than 15 TPY | Every 5 years | Every 2 years |
| Severe Non-Attainment | Greater than or equal to 15 TPY | Annually | Annually |
| Extreme Ozone Non-Attainment | Any Emissions | Every 5 years | Every 2 years |
CDPHE has developed an updated GP12 modeling workbook to help inform operators of their potential to exceed modeling thresholds. There are ten distinct regions. The GP12 workbooks are region-specific and are accessible here: General Permit 12 for oil and gas operations and workbooks.
Operators should also consider how GP12 may affect overall permitting costs when compared with other available general permits. For facilities that are transitioning from GP09 or GP10 coverage to individual equipment-specific permits, the GP12 may provide a more cost-effective path. For example, a GP12 fee is $5,629 plus $675 for each required APEN, while a single GP02 for a natural gas-fueled engine is $3,589.40 plus the $675 APEN fee. In situations where a facility has multiple engines or several equipment types requiring individual permits, GP12 may reduce permitting fees while also consolidating applicable requirements under one permitting framework.
GP12 includes flexibility through the concept of Alternative Operating Scenarios (AOS). This allows operators to plan for potential equipment or operational changes within the permit itself, reducing the need for frequent permit revisions. An additional element of the AOS operators should be aware of is qualifying for like-kind replacement includes having identical stack characteristics. When used effectively, this can streamline facility management and provide more adaptability as operations evolve over time.
Conclusion
Overall, GP12 represents a shift toward a more site-specific and operationally aligned permitting framework for Colorado well production facilities. While GP09 and GP10 provided a simpler, standardized approach, GP12 places greater emphasis on equipment-specific APENs, facility-specific emissions data, and planning for future operating scenarios. Operators should evaluate upcoming permitting needs, strengthen data collection and compliance tracking practices, and determine where GP12 may provide long-term operational or cost advantages.
