Air Pollution Control Strategies Archive
This page provides an archive of information about control strategies that the RAQC has previously considered or helped enact. For information about control strategies that the RAQC is currently exploring, please visit the Air Pollution Control Strategies page.
Control Strategies Previously Evaluated
A previous list of strategies being evaluated is available for review and feedback. The following sections provide summaries of additional strategies that have been undergone initial assessment and have been presented in Control Strategy Committee meetings.
Diesel Inspection and Maintenance
This strategy aims to mitigate emissions from on road diesel engines by expanding the existing diesel inspection and maintenance (I/M) program. Possible expansions of the program could include testing of NOx and VOC or adding an On Board Diagnostic (OBD) assessment. A preliminary analysis (October 2019) of this strategy is available for review.
Low-Emissions Diesel Fuel
This strategy aims to reduce emissions from heavy-duty diesel sources through the implementation of a low emissions diesel (LED) fuel standard. LED fuel is characterized as having a:
- •Maximum aromatic hydrocarbon content of 10% by volume
- •Minimum cetane number of 48
A preliminary analysis (October 2019) of this strategy is available for review.
Green Construction
This strategy aims to mitigate emissions associated with construction through the establishment of Best Operational Practices and public bid processes for use by local governments that will encourage the use of Tier 3 or 4 equipment. A preliminary analysis (October 2019) of this strategy is available for review.
Heavy-Duty Equipment Usage Restrictions
This strategy aims to reduce emissions from non-road sources by implementing usage restrictions on heavy-duty diesel equipment. These includes seasonal/episodic usage restrictions or tier type usage restrictions. A preliminary analysis (October 2019) of this strategy is available for review.
Establishment of Air Quality Fund
Establish dedicated fund to develop and implement projects that will benefit air quality through the implementation of fees. Projects include:
- • Emission Control Strategies
- • Capital Investments in Clean Technology
- • Elimination of older/dirtier equipment
- • Enforcement measures
A preliminary analysis (October 2019) of this strategy is available for review.
Low RVP Fuels
RAQC, and other state government agencies, are working together to evaluate strategies aimed at reducing ozone precursor emissions through the analysis of changes to motor gasoline specifications. Currently, 7.8 psi RVP gasoline with a 1 psi ethanol waiver is used in the ozone nonattainment area. A study was conducted in the spring of 2019 to determine the potential impacts of switching to a more stringent gasoline formula. A preliminary analysis (October 2019) of the strategy is available for review. A copy of the study and additional information on the low RVP fuels strategy can be found here.
Indirect Source Rule
This strategy aims to mitigate emissions associated with the construction and operation of indirect sources. Indirect sources include facilities, structures, buildings, etc. which can reasonably be expected to cause or induce substantial mobile source activity that result in emissions of air pollutants that might reasonably be expected to interfere with the attainment and maintenance of the national ambient air quality standards. The report for Equity Analysis of Indirect Sources provided by FHU can be found here (August 2023). The report for Colorado Indirect Sources Market Study provided by FHU can be found here (August 2023). The report for Analysis of Future Indirect Sources provided by FHU can be found here (August 2023). The report for Analysis of Existing Indirect Sources provided by FHU can be found here (August 2023). A preliminary analysis (December 2019) of the strategy is available for review.
Anti Idling Program
An anti-idling program expansion aims to reduce emissions associated with idling light-, medium-, and heavy-duty vehicles. A preliminary analysis (December 2019) of the strategy is available for review.
Low Carbon Fuel Standard/Clean Fuel Program
A Low Carbon/Clean Fuel Standard would reduce carbon emissions from the transportation sector by regulating the carbon intensity of transportation fuels. A preliminary analysis (December 2019) of the strategy is available for review.
Light Duty Inspection and Maintenance
This strategy aims to mitigate emissions from on-road light-duty vehicles by lowering the emission limits of the current inspection and maintenance (I/M) program. The Air Pollution Control Division conducted a study on projected emission reductions at different emission limits. A preliminary analysis (January 2020) of this strategy is available for review.
Vehicle Electrification
Zero Emission Vehicles (ZEV) and the associated charging station infrastructure are a critical strategy in reducing emissions from light, medium and heavy-duty mobile sources. Strategies associated with expanding the use of ZEVs include expanding charging infrastructure, exchanging high emitters for electric vehicles, and electrifying tourism. A preliminary analysis (January 2020) of this strategy is available for review.
Commuter Trip Reduction Program
A commuter trip reduction strategy would be aimed at lowering vehicle miles traveled in the nonattainment area by working with employers to mitigate the number of employees traveling to work in single occupancy vehicles. The RAQC has compiled many resources on commuter trip reduction programs that are available on the Employer-Based Trip Reduction Program Resource page.
Extended Ozone Outlook
This strategy would create an “extended ozone outlook” for the general public in the nonattainment area. Providing the general public with an extended outlook would all individuals additional time to plan out personal ozone limiting actions. Additional information on this strategy is available for review.
Out of Area Vehicle Inspection
This strategy would increase public outreach regarding vehicle inspections to drivers outside the nonattainment area who frequently travel/commute to the nonattainment area. A preliminary analysis (February 2020) of this strategy is available for review.
Motorized Boating Restrictions
This strategy aims to mitigate emissions associated with boating activities within the nonattainment area by limiting motorized boating on high ozone days. A preliminary analysis (February 2020) of this strategy is available for review.
Control Strategies Currently Enacted
Clean Air Fleets
The Clean Air Fleets program, started in 2003, is a regional public-private initiative to educate on- and off-road diesel vehicle operators on how to voluntarily reduce diesel emissions while saving money. The program provides information on, and funding for, simple retrofit technologies and fuels to reduce emissions. The Clean Air Fleets website at www.CleanAirFleets.org provides the latest program information and provides resources on advances in diesel engines, emissions control, idling reduction technology, alternative fuels, engine and fuel standards, and much more. Download the program overview
Lawn & Garden
The Regional Air Quality Council conducted a stakeholder process during 2023 to develop its Lawn & Garden emission reduction strategy and received the RAQC Board endorsement of the proposal. The proposed regulation and supporting documentation below were submitted and scheduled for hearing by the Air Quality Control Commission, culminating in a rulemaking in December 2023. The RAQC proposal addressed Lawn & Garden emission controls to reduce ozone for nonattainment area planning efforts to reach compliance with National Ambient Air Quality Standards during the 2024-26 time frame, as well as to reduce greenhouse gases and toxic air contaminants. The AQCC passed a Lawn & Garden regulation in February 2024 that took effect in April 2024 that focused on banning the use of certain gas-powered lawn and garden equipment on government property.
Simple Steps. Better Air.
Simple Steps. Better Air is a voluntary program lead by the RAQC. It is administered in the Denver Metropolitan area and by the North Front Range Metropolitan Planning Organization (NFRMPO) in Larimer and Weld Counties. The Simple Steps. Better Air program provides information and education about ozone pollution and strategies to address the creation of ozone pollution. More information is available at www.simplestepsbetterair.org/
Mow Down Pollution
Mow Down Pollution is a voluntary program implemented by the RAQC. Mow Down Pollution provides free recycling of gasoline–powered lawn mowers and reduced pricing on the purchase of new, cordless, electric lawn mowers. More information on the Mow Down Pollution program can be found at www.mowdownpollution.org
Low/Zero Emission Vehicles
In response to Executive Order B 2018 006 and Executive Order B 2019 002 the Air Quality Control Commission (AQCC) passed Regulation 20 – The Colorado Low Emission Automobile Regulation. The Regulation makes Colorado the 10th state to join California’s ZEV program.
Rulemakings
APCD LEV Rulemaking (Approved Nov. 16, 2018) APCD ZEV Rulemaking (Approve Aug. 16, 2019)
Presentations
LEV/ZEV Overview (Jan. 2016 MS/F Committee Mtg, APCD)
Enhanced Inspection and Maintenance
Under the Clean Air Act, nonattainment areas classified as Moderate or higher are required to implement a motor vehicle inspection and maintenance (I/M) program as part of the State Implementation Plan. To attain the carbon monoxide (CO) NAAQS, the Denver metropolitan area was required to implement an “enhanced” I/M Program. Colorado began implementing an enhanced program in 1995 and continues to implement it in the Denver metropolitan seven–county area, including Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, and Jefferson counties. In 2010, parts of Larimer and Weld Counties in the North Front Range area were added to the program area as a State–Only requirement. More information on the program is available on the Colorado Department of Public Health and Environment’s website.
Optical Gas Imaging Camera Loans
In 2011, the Regional Air Quality Council (RAQC) received a Supplemental Environmental Project (SEP) grant from the Colorado Department of Public Health and Environment (CDPHE) to acquire an OGI Camera for the purpose of loaning out to Qualified Users (i.e., industry representatives, local government, health department, and university staff) to identify and repair gas leaks primarily at oil and gas industry exploration and production facilities across Colorado. In addition, the RAQC provides periodic training to potential Qualified Users to become level 1 certified, which enables individuals to borrow the camera for such activities. The availability of this camera has been instrumental in the identification of hundreds of leaks in the Denver Metro/North Front Range nonattainment area and the RAQC plans to continue this program for the foreseeable future.
Low VOC AIM Coatings and Consumer Products
To address VOC emissions from consumer products and Architectural and Industrial Maintenance (AIM) coatings, the RAQC and the Colorado Air Pollution Control Division (APCD) investigated the feasibility of adopting model rules crafted by the Ozone Transport Commission (OTC) based on California Air Resources Board (CARB) regulations. This was identified as a viable control strategy and was developed into a rulemaking. Regulation 21, the Low VOC Architectural and Industrial Maintenance (AIM) coatings and consumer products rule, was approved by the Air Quality Control Commission and will go into effect May 21st, 2020. Additional information is available here.
Street Sanding/Sweeping
In conjunction with local and state street maintenance departments, the RAQC developed a street sanding program, which has achieved a weighted average region-wide emissions reduction of approximately 50% and has allowed us to comply with the PM10 federal standard since 1993. The Street Sanding Program was originally incorporated into the federally approved PM10 State Implementation Plan (SIP) as Air Quality Regulation No. 16 in 1993. The Regulation was revised a number of times and was last updated by the State in 2000 for the 2001 PM10 SIP. Our challenge now is to maintain current street sanding practices in the face of increasing vehicle traffic and significant budget constraints in some jurisdictions. Additional program information and related reports are available here.
Reasonably Available Control Technology
As a Moderate nonattainment area for ozone, the Denver Metro/North Front Range region is required by the Clean Air Act to implement Reasonably Available Control Technology (RACT) for all major sources within the nonattainment area. For a Moderate area, major source is defined as a source that emits 100+ tons per year (tpy) of nitrogen oxides (NOX) or volatile organic compounds (VOC). This threshold for what is considered a ‘major sources’ gets tighter as the region is reclassified to higher levels under the various ozone standards. As a region on the cusp of becoming a Serious nonattainment area, the major sources threshold has the potential to go down to 50 tpy as soon as January 2020. As a result, the Colorado Air Pollution Control Division (APCD, or Division) continues to work with stakeholders in developing RACT for major sources of NOx or VOCs in the Denver Metropolitan/North Front Range Moderate ozone nonattainment area.
Further Information
Colorado Air Pollution Control Division (APCD)
Presentations
RACT for New Major Sources (May 2019) Colorado’s MS RACT Efforts (Sept. 2017)