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State of Colorado Provisions to Meet the Requirements

of Section 110(a) (1) and (2) of the Clean Air Act

Section 110 (a)(1) State Implementation Plan for National Ambient Air Quality Standards

Colorado has established the following State Implementation Plan local elements to address 

criteria pollutants in areas that have violated the National Ambient Air Quality Standards 

(NAAQS)

NAAQS Location Status

1-Hour Ozone Denver Attainment since 2001

1997 8-Hour Ozone Northern Front Range Ozone 

Area

Nonattainment effective November 20, 2007. Ozone 

Action Plan SIP revision submitted to EPA June 18, 

2009. Approved by EPA, August 5, 2011 (76 FR 47443)

2008 8-Hour Ozone Northern Front Range Ozone 

Area

Nonattainment (marginal classification) effective July 20, 

2012. (77 FR 30088)

Nitrogen Oxide Denver Attainment since 1984

Lead Denver Attainment since 1984

Carbon Monoxide Colorado Springs Attainment since 1999

Carbon Monoxide Denver Attainment since 2002

Carbon Monoxide Fort Collins Attainment since 2003

Carbon Monoxide Greeley Attainment since 1999

Carbon Monoxide Longmont Attainment since 1999

PM10 Aspen Attainment since 2003

PM10 Canon City Attainment since 2001

PM10 Denver Attainment since 2002

PM10 Lamar Attainment since 2005

PM10 Pagosa Springs Attainment since 2001

PM10 Steamboat Springs Attainment since 2004

PM10 Telluride Attainment since 2001

Section 110 (a)(2)(A) - Emission Limits and Other Control Measures

Enforceable emission limits and control measures are detailed in the various Air Quality Control 

Commission regulations for all sources of criteria pollutants, regulated New Source Review 

pollutants, as well as hazardous air pollutants, CFCs, smoke and odors. A summary of the 

regulations is found below under section 110 (a)(2)(C).

The enforceable emission limits also apply to periods of startup, shutdown and malfunction. The 

Colorado Common Provisions Regulation, Sections II. E. and II. J. contain emission control 

provisions specific to startup, shutdown and malfunction events that are in Colorado’s SIP, 

which was approved by EPA on August 7, 2008 (73 FR 45879).

Section 110 (a)(2)(B) - Ambient Air Quality Monitoring and Data System

The provisions for episode monitoring, data compilation and reporting, public availability of 

information, and annual network reviews are found in the federally-approved statewide monitoring 

SIP (58 FR 49435). 
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As part of the Monitoring SIP, Colorado submits a Colorado Annual Monitoring Network Plan each 

year for EPA approval. The plan details monitoring locations for all criteria pollutants, including the 

EPA’s Ozone monitoring requirements under the the 2008 Ozone NAAQS, and lists the quality 

assurance accuracy audits and precision check methods performed for each monitor.

The Colorado Air Pollution Control Division (Division) periodically submits a Quality Management 

Plan and a Quality Assurance Project Plan to EPA Region VIII. These plans cover procedures to 

monitor, analyze data and report data to an EPA central database.

The State of Colorado has an approved monitoring SIP, a plan and authority for monitoring, and the 

ability to properly handle all related data.

Section 110 (a)(2)(C) - Program for Enforcement of Control Measures

Colorado has an approved SIP regulating the construction and modification of stationary sources as 

necessary to assure that the NAAQS are achieved (Colorado Air Quality Control Commission 

Regulation 3), including a New Source Review (NSR) permitting program as required in Title I, 

Parts C and D of the federal Clean Air Act. Colorado has an approved SIP which provides for the 

enforcement of the control measures required by Clean Air Act Section 110 (a)(2)(C).

Many of the Colorado Air Quality Control Commission regulations address, in some manner, the 

programs for enforcement of control measures. Some of these regulations and other relevant 

Colorado-specific programs that are in the SIP are described below:

 Regulation 1, Particulates, Smokes, Carbon Monoxide, and Sulfur Dioxides -- Regulation 1 sets 

forth emissions limitations, equipment requirements, and work practices (abatement and control 

measures) intended to control the emissions of particulates, smoke and sulfur oxides from new 

and existing stationary sources. Control measures specified in this regulation are designed to 

limit emissions into the atmosphere and thereby minimize the ambient concentrations of 

particulates and sulfur dioxides. 

 Regulation 3, Stationary Source Permitting and Air Pollution Emission Notice Requirements --

Regulation 3 provides for a procedural permitting program and requires air pollution sources to 

file Air Pollutant Emissions Notices (APENs). The regulation also requires that new or modified 

sources of air pollution, with certain exemptions, obtain preconstruction permits, and to meet the 

federal requirements of Prevention of Significant Deterioration (PSD) and Non-attainment New 

Source Review (NNSR). Colorado’s NSR program applies to all regulated NSR pollutants, 

including GHGs.

Regulation 3 has been revised to incorporate PM2.5 emissions. On May 16, 2008, October 20, 

2010, April 6, 2011 and May 18, 2011, EPA promulgated a series of rules regarding the 

regulation of PM2.5 under the NSR permitting program. On November 15, 2007, Colorado’s 

Air Quality Control Commission adopted rule revisions that incorporated PM2.5 into the APEN 

and minor source permitting programs. EPA promulgated its final PM2.5 NSR 

Implementation Rules in 2010, which specifies how PM2.5 emissions are treated for PSD 

and major source NSR sources. On October 20, 2011, Colorado’s Air Quality Control 
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Commission adopted rule revisions requiring major sources in the state to be subject to PSD and 

NSR permitting thresholds for PM2.5 at the same level as PM10. The 2007 revision was 

submitted to the EPA in 2008. The 2011 revision has been submitted to EPA.

Colorado’s minor source and PSD permitting programs apply to sources that emit GHG in 

accordance with EPA’s Tailoring Rule. The Colorado Air Quality Control Commission on 

October 21, 2010, adopted revisions throughout Regulation Number 3 to address GHG 

regulation in Colorado. These revisions were made to incorporate EPA’s GHG Tailoring 

Rule into Colorado’s Title V and PSD Permitting Programs, and to extend synthetic minor 

permitting to Colorado’s stationary sources seeking federally enforceable limits to avoid 

major source or major stationary source applicability thresholds specific to GHG. On 

October 20, 2011, Colorado’s Air Quality Control Commission adopted rule revisions that 

incorporated EPA’s Biogenic CO2 Deferral into Regulation 3. The 2010 revision has been 

submitted to EPA.

Regulation 3 also was revised in 2008 to address ozone formation in the Denver Metro 

Area/North Front Range Ozone nonattainment area. Specifically, the Commission adopted 

revisions to remove and/or revise several categorical APEN reporting and/or permitting 

exemptions in order to improve the Division’s emissions inventory and for the sake of equity. 

The revisions are part of the federally-enforceable SIP and help Colorado make progress 

toward eventual compliance with the 2008 Ozone NAAQS set at 0.075 ppm. 

 Regulation 4, Woodburning Controls -- Regulation 4 requires that new woodstove and fireplace 

inserts meet the federal certification requirements in specified areas of Colorado.

 Regulation 7, Control of Ozone via Ozone Precursors and Nitrogen Oxides -- Regulation 7 

controls the emissions of volatile organic compounds, primarily in the Denver-metro area. It sets 

standards and mandates controls for specific types of volatile organic compound sources. In 

2008, Regulation 7 was revised to increase control requirements for oil and gas condensate 

tanks, glycol dehydrators and reciprocating internal combustion engines. These revisions were 

submitted to EPA in 2009 as part of the state’s State Implementation Plan for the 1997 Ozone 

Standard. EPA approved the associated Ozone attainment demonstration. 

 Regulation 11, Motor Vehicle Inspection -- Regulation 11 requires automobile emission

inspection and maintenance programs to be implemented in specified areas of the state for 

gasoline powered on-road vehicles. These programs apply to businesses, industry, and the 

general public. In addition, the State’s Automobile Inspection and Readjustment (AIR) 

program’s purpose is to reduce motor vehicle related pollution through the inspection and 

emissions related repair of automobiles. The program, as defined in Regulation 11, works in 

specific areas of the State of Colorado and requires motor vehicles to meet emission standards 

through periodic inspection and, as necessary, repair.

 Regulation 16, Street Sanding and Sweeping -- Regulation 16 sets specification standards for 

street sanding material and street sweeping practices in the Automobile Inspection and 

Readjustment program area and Denver-metro particulate attainment/maintenance area.

 Common Provisions Regulation -- The Division may require owners and operators of 
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stationary air pollution sources to install, maintain, and use instrumentation to monitor and 

record emission data as a basis for periodic reports to the Division under the provisions of the 

Colorado Air Quality Control Commission Common Provisions regulation. Also, the 

Common Provisions Regulation contains emission control provisions specific to startup, 

shutdown and malfunction events that are in Colorado’s SIP, which was approved by EPA on 

August 7, 2008 (73 FR 45879). 

Section 110 (a)(2)(D)(i) - Interstate Transport

For interstate transport, the SIP needs to contain four provisions to ensure that Colorado emissions 

and pollutants do not:

 significantly contribute to nonattainment in another State (Prong 1); 

 interfere with maintenance of the NAAQS by another State (Prong 2);

 interfere with another State’s measures to prevent significant deterioration of air quality

(Prong 3); and 

 interfere with another State’s measures to protect visibility (Prong 4).

Colorado has addressed federal interstate transport requirements for the 1997 ozone and PM2.5 

NAAQS with an interstate transport SIP revision submitted to EPA March 31, 2010. EPA has since 

approved all four prongs of Interstate Transport for both the 1997 Ozone and PM2.5 standards. 

EPA has not provided Interstate Transport (IT) Guidance for the 2008 Ozone standard which 

establishes any additional technical requirements associated with demonstrating whether a state has 

transport impacts on a nearby state(s). Colorado will review such guidance when it becomes 

available. Based on consideration of the distance between Colorado and the nearest downwind 

nonattainment areas in Arkansas, Missouri and Texas, as well previous interstate transport analyses 

and beneficial changes in Colorado’s emissions inventory, Colorado does not believe that it 

significantly contributes to nonattainment or interferes with maintenance in another state. 

With regards to the 2006 PM2.5 standard, the Colorado Air Quality Control Commission 

approved an Interstate Transport SIP in December 2011, which was submitted to EPA May 11.

Prong 3 of Interstate Transport deals with prevention of significant deterioration. As explained 

under section 110 (a)(2)(C), Colorado has revised its SIP through revisions to Regulation No. 3 

in 2007, 2010 and 2011 to have a PSD program that meets all federal requirements and that 

applies to all regulated NSR pollutants.

Thus, the implementation of Colorado’s PSD and NNSR permitting programs prevent significant 

deterioration in neighboring states and thereby satisfy the PSD portion of 110(a)(2)(D)(i)(II) of 

the CAA. Colorado’s PSD and NNSR permitting programs require that demonstrations be made 

for all areas that are potentially impacted by emissions from a proposed major source or 

modification. A PSD permit may not be issued unless the new or modified source demonstrates 

that emissions from the construction or operation of the facility will not cause or contribute to air 

pollution in any area that exceeds any NAAQS.
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A NNSR permit may not be issued unless the source shows it has obtained sufficient emissions 

reductions to offset increases in emissions of the pollutants for which an area is in nonattainment, 

consistent with reasonable further progress toward attainment.

Prong 4 of Interstate Transport relates to visibility. EPA approved Colorado’s Regional Haze SIP on 

on September 10, 2012, when the Regional Administrator signed final rulemaking that is 

awaiting publication in the Federal Register. Colorado relies on its Regional Haze SIP to 

demonstrate that the state does not interfere with visibility in any other state.

Section 110 (a)(2)(D)(ii) – Interstate and International Transport 

The EPA guidance from October 14, 2011, indicates that states have no obligation at this time 

under Sections 115, 126 (b) and 126(c) of the CAA regarding interstate or international transport 

because there are no petitions or pending actions before EPA under these sections. Furthermore, 

the control measures in the SIP protect not only Colorado from NAAQS violations, but 

neighboring states and countries as well.

However, the guidance indicates an obligation under Section 126(a) that directs each SIP to 

include provisions requiring new or modified sources to notify neighboring states of potential 

impacts from the sources. Colorado’s approved NSR program has a regulatory provision in place 

that requires notification of neighboring states of potential impacts from sources, specifically, 

Regulation No. 3, Part D, Section IV, provides for notice to any state, tribal governing body, 

federal land manager or local agency that may be affected by emissions from a major source or 

major modification subject to the PSD program.

Clean Air Act Section 110 (a)(2)(E) - Adequate Resources, State Boards, and Authority

Personnel, Funding, and Authority

There are no state or federal provisions prohibiting the implementation of any provision of the 

Colorado SIP. In general, Colorado provides the necessary assurances that funding, personnel, and 

authority exist and that the State of Colorado has responsibility for implementing local provisions. 

The Air Quality Control Commission adopted all of the regulatory provisions in the SIP pursuant to 

authority delegated to it by statute. The Commission’s general authority to adopt the rules and 

regulations necessary to implement the SIP is set out in the Colorado Air Pollution Prevention and 

Control Act Section 25-7-105 of the Colorado Revised Statutes (C.R.S.). The general authority for 

the Division to administer and enforce the program is set out at 25-7-111, C.R.S. Additional 

authority to regulate air pollution and implement provisions in the SIP is set out elsewhere in the 

Colorado Air Pollution Prevention and Control Act, Article 7 of Title 25. In addition, the 

Commission and the Division have the authority delegated to them in Sections 42-4-301 through 

42-4-316, C.R.S. (concerning motor vehicle emissions) and 42-4-414, C.R.S. (concerning emissions 

from diesel-powered vehicles). 

The Air Quality Control Commission’s authority includes the authority to regulate particulate 

emissions, regardless of size (Section 25-7-109 (2)(b), C.R.S.).

The Division has staff and an annual budget to operate its six programs (Stationary Sources, Mobile 

Sources, Indoor Environment, Technical Services, Planning and Policy, Administrative Services). 
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The Division employed 161 people and had a budget of $21.2 million for fiscal year 2011.

Of the total budget, 21 percent was derived from federal grants, 31 percent from mobile source fees, 

43 percent from stationary source fees, and 5 percent from other cash sources.

State Boards

Section 128 of the CAA indicates Colorado’s State Implementation Plan must contain requirements 

that any board or body which approves permits or enforcement orders under the CAA must have a 

majority of members who represent the public interest and do not derive any significant portion of 

their income from persons subject to permits or enforcement orders.

The Air Quality Control Commission’s Procedural Rules, section 1.11.0 state that “The 

Commission shall have at least a majority of members who represent the public interest and do 

not derive a significant portion of their income from persons subject to permits or enforcement 

orders under this article or under the federal act. The members of the Commission shall disclose 

any potential conflicts of interest that arise during their terms of membership to the other 

Commissioners in a public meeting of the Commission.” AQCC Procedural Rules, section 1.11.0 

were incorporated into Colorado’s SIP and approved by EPA on January 4, 2012 (77 FR 235).

Relationships with other agencies responsible for carrying out State activities

The Division contracts with local governments in two distinct ways:

1. Colorado grants monies to local health departments to endow them as agents of the State to 

provide inspections of some local stationary sources, asbestos abatement jobs, and CFC 

sources. Some local health departments also operate gaseous and particulate monitors under 

contract for the state. These efforts must comply with federal and state regulations.

2. Colorado grants monies to local governments to help pay for their support of SIP elements 

via public and private partnerships, education and informational campaigns. Most of these 

agencies create their own work plan that consists of programs they believe will help enhance 

air quality in their communities in accordance with general SIP directives. 

Colorado has adopted specific regulations for local attainment/maintenance areas to assure these 

areas meet requirements of the state SIP. These regulations include The Colorado Air Quality 

Control Commission SIP-specific regulations, 5 CCR 1001-20. These regulations provide the 

necessary authority for the Division to adequately enforce the provisions of the SIP elements in 

local attainment/maintenance areas.

In addition, Colorado retains its full authority and responsibility to enforce the SIP and the Colorado 

Pollution Prevention and Control Act in local jurisdictions under the local government provisions of 

25-7-128, C.R.S. 

Clean Air Act Section 110 (a)(2)(F) - Stationary Source Monitoring and Reporting

Colorado Air Quality Control Commission Regulations 1, 3, and 7, as well as the Common 

Provisions Regulation, address the issue of stationary source monitoring.

Colorado Regulation 1 sets forth emission limitations, equipment requirements and work practices 

(abatement and control measures) intended to control the emissions of particulates, smoke, and 
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sulfur dioxides from new and existing stationary sources.

An Air Pollutant Emission Program is required in the Colorado Pollution Prevention and Control 

Act Section 25-7-114.1, C.R.S. APEN requirements are further defined in Regulation 3, which 

requires stationary sources to report their emissions on a regular basis through APENs. These 

requirements are found in Regulation 3, Part A, Section II, “Air Pollutant Emission Notice 

Requirements.”

Regulation 3 also requires stationary sources to monitor their emissions under certain conditions. 

Part A. Section VIII requires monitoring performed in accordance with EPA accepted procedures, 

and record keeping of air pollutants.

Regulation 3 also provides for a permitting program that establishes emission limitations and 

standards. Emissions must be reported by sources to the state for correlation with applicable

emissions limitations and standards. Monitoring may be required for both construction and 

operating permits. 

Regulation 7 includes requirements for owners and operators of VOC sources to conduct 

monitoring, keep records, and report results to the Division.

The Common Provisions Regulation may require owners and operators of stationary air pollution 

sources to install, maintain, and use instrumentation to monitor and record emission data as a basis 

for periodic reports to the Division.

Section 110 (a)(2)(G) - Emergency Power

The State has the authority to implement emergency powers similar to Section 303 of the Clean Air 

Act. First, the EPA-approved “Denver Emergency Episode Plan” (74 FR 47888) addresses ozone, 

particulate matter, and carbon monoxide for the Denver metro region and requires the State to

implement protective measures when air quality exceeds defined thresholds. 

Additionally, the Colorado Pollution Prevention and Control Act, Sections 25-7-112 and 25-7-113,

C.R.S. generally describe Colorado’s authority regarding air pollution emergencies for any air 

pollutants endangering public health, welfare or the environment anywhere in the state. These 

sections provide authority comparable to CAA Section 303. The Colorado act allows the Division to 

issue a cease-and-desist order if conditions warrant, and to apply for a restraining order or injunction 

in district court. Sections 25-7-112 and 113, C.R.S. also allow the Governor to declare a state of air 

pollution emergency and take any and all actions necessary to protect the health of the public.

As described in EPA’s September 25, 2009 guidance, areas that have had a PM2.5 exceedance 

greater than 140.4 ug/m3 should have an emergency episode plan. If no such concentration was 

recorded since 2006, the state can rely on its general emergency authorities. Colorado has never 

recorded such a PM2.5 level and thus an emergency episode plan for PM2.5 is not necessary. 

Nevertheless, the State hereby certifies that it has the appropriate emergency powers to address 

PM2.5 episodes, as described above.
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Additionally, the State implements EPA’s air quality index system and typically issues alerts and 

advisories to the public when any pollutant is expected to or exceeds an AQI index value of 100. If 

pollutant concentrations are expected to or actually exceed EPA’s recommended index value 

thresholds of 201 (alert), 301 (warning), 350.5 (significant harm), or 401 (emergency), the State can 

invoke emergency powers.

Section 110 (a)(2)(H) - Provisions for SIP Revisions Due to NAAQS Changes 

or Findings of Inadequacies

The State of Colorado has the ability and authority to address and revise the State Implementation 

Plan due to changes in the NAAQS or due to findings of inadequacies.

The Colorado Air Quality Control Commission has the authority and the duty to adopt and revise a 

State Implementation Plan as necessary to comply with the federal requirements. Colorado Air 

Pollution Prevention and Control Act, Section 25-7-105 (1)(a)(I), C.R.S. directs the Colorado Air 

Quality Control Commission to promulgate rules and regulations as related to a comprehensive SIP

which will assure attainment and maintenance of the NAAQS and which will prevent significant 

deterioration of air quality in the State of Colorado. The Colorado Act states that the 

comprehensive SIP shall meet all requirements of the federal act and shall be revised whenever 

necessary or appropriate.

Colorado Air Pollution Prevention and Control Act Section, 25-7-109, C.R.S. also gives the 

Colorado Air Quality Control Commission the authority to promulgate emission control regulations.

Section 110 (a)(2)(I) – Provisions for Nonattainment Areas to Meet the Applicable 

Requirements of Part D

While the EPA 110 SIP guidance of both October 2, 2007, and October 14, 2011, excludes the 

need for determinations under Part I, Colorado meets the applicable requirements for SIPS and 

SIP revisions in nonattainment areas under the Colorado Air Quality Control Commission’s 

Regulation 3, Part D, as explained above.

Section 110 (a)(2)(J) – Consultation with government officials, Public Notification, 

Prevention of Significant Deterioration of Air Quality and Visibility Protection

Consultation with Government Officials

The Colorado Air Pollution Prevention and Control Act 25-7-105(1)(d), C.R.S. requires a

satisfactory process of consultation with general purpose local governments and any federal land 

manager having authority over federal land to which the state implementation plan applies, 

pertaining to transportation controls, air quality maintenance plan requirements, preconstruction 

review of stationary sources of air pollution, or any measure referred to in the PSD or the NNSR 

permitting programs, or granting delayed compliance orders pursuant to Section 25-7-118, C.R.S.

Colorado’s Transportation Conformity Rule, Regulation 10, Part III, specifies in detail the process 

for interagency consultation related to transportation conformity in SIP planning. The rule sets out 

the minimum requirements and roles and responsibilities for interagency consultation (Federal, 
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State, regional and local) and resolution of conflicts.

Consultation requirements are also detailed in Chapters 2 and 10 of Colorado’s Regional Haze SIP. 

The chapters specify the consultation process with federal land managers, tribes and other states, 

both during the development of the plan and in future commitments under the plan.

Local government coordination and consultation is also described in 25-7-128, C.R.S. which covers 

local government’s authority to enact air pollution resolutions or ordinances, standards and 

regulations, their submission and enforceability as part of the SIP, and the coordination of air 

pollution plans and programs between the state and local governments.

Engineering and meteorological consultation is provided by the State to local agencies. The State 

assists local agencies in planning air management programs for their respective areas. The Colorado 

Air Quality Control Commission holds public meetings and hearings on all SIP revisions in 

accordance with the Air Quality Control Commission Procedural Rules. Public comment is solicited 

and accepted at Colorado Air Quality Control Commission meetings and hearings.

Public Notification

Colorado notifies the public of instances or of areas in which any national primary ambient air 

quality standard is exceeded through the website and public announcements. Included in this 

notification are public awareness announcements regarding health hazards and manners in which 

the public can participate in regulatory and other efforts to improve Colorado’s air quality. Not only 

does the State provide after-the-fact information about readings in excess of the NAAQS, the 

Denver PM10 SIP provides for advance warnings to the public that the NAAQS may be exceeded 

whenever meteorological conditions make it possible or likely for ambient concentrations to exceed 

the NAAQS.

The Air Quality Control Commission also issues an annual Report to the Public, as part of its duties 

under 25-7-105, C.R.S. which notifies the public of areas of NAAQS exceedances statewide, 

associated health hazards, and how the public can participate in regulatory and other efforts to 

improve air quality. The Report to the Public is distributed through the Commission’s mailing list 

and posted on the Commission’s public website.

The Division prepares a daily public notification in the form of an Air Pollution Advisory for a

nine-county Denver-Boulder metropolitan and North Front Range area and the communities of 

Grand Junction, Fort Collins, Greeley and Colorado Springs. The advisory is posted on the 

Division website and includes details of the day’s air quality and visibility, a forecast of the 

coming day’s air quality, residential burning restrictions and voluntary motor vehicle driving 

reduction requests during the winter high pollution season. The advisory includes links to an 

open burning forecast and other important information such as the day’s Air Quality Index, the 

health effects of specific pollutants and measures that can be taken by the public to reduce 

exposure. While not part of Colorado’s SIP, the advisories are part of an ongoing commitment 

by the State to inform and educate citizens about air quality.

In addition to the daily Front Range and Grand Junction air quality forecasts, the state has 

expanded its forecasting and notification abilities statewide. The state utilizes data from monitors 
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throughout Colorado and will issue a health advisory if monitors show, or are expected to show, 

an exceedance of air quality standards.

The state issues statewide smoke and blowing dust advisories when conditions show that such an 

event is imminent or in process. The advisories include public notification and education elements, 

and inform the public about actions to take during imminent blowing dust and wildfire events that 

could lead to high levels of particulate matter.

The smoke and blowing dust advisories may be issued as part of EPA-approved Natural Events 

Action Plans that have been developed for Lamar and Alamosa, and for wildfires. The advisories 

may also be issued independently of such Natural Events Action Plans for communities not 

covered by the plans. 

Other Colorado communities also maintain and operate daily air quality forecasts, including 

Mesa County on the Western Slope and El Paso County in the Colorado Springs area.

Prevention of Significant Deterioration of Air Quality and Visibility Protection

Prevention of Significant Deterioration

Colorado Air Quality Control Commission Regulation 3 (Stationary Source Permitting and Air 

Pollution Emission Notice Requirements), Regulation 6 (Standards of Performance for New 

Stationary Sources) and Colorado’s Long Term Strategy for Visibility Protection adequately 

address Prevention of Significant Deterioration and Visibility Protection. For example, new major 

stationary sources or major modifications are restricted in their emissions in order to protect the 

PSD increment under Colorado Air Quality Control Commission Regulation 3. PSD and visibility 

analyses are also required by NSR regulations of Colorado. Colorado is required to review new 

major stationary sources and major modifications prior to construction to assess potential impacts 

on visibility in any Class I Area. Colorado Air Quality Control Commission Regulation 3.XI.E, 

“New Source Review” (Appendix D) describes the applicant’s demonstration that the proposed 

source will not have an adverse effect on visibility in Class I Areas. 

Visibility

Colorado relies on its Regional Haze SIP to protect visibility. The Regional Haze SIP received 

approval from the U.S. EPA on September 10, 2012, when the Regional Administrator signed 

final rulemaking that is awaiting publication in the Federal Register.

In addition, The Interstate Transport SIP submitted to EPA on March 31, 2010 and approved by 

EPA (77 FR 1027, 75 FR 31306, 76 FR 22036), demonstrates that there is a significant 

downward trend in Colorado’s visibility impairing emissions, visibility in surrounding 

Mandatory Class I Areas is improving over time, and regional modeling indicates that Colorado 

has an extremely small contribution to out-of-state haze. Thus, air pollution sources and other 

types of emission activity within the State of Colorado do not interfere with measures required to 

be included in the applicable implementation plan of another state to protect visibility.

Clean Air Act Section 110 (a)(2)(K) - Air Quality Modeling and Data Handling
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Colorado has the authority and resources to model for all criteria pollutants. Air quality modeling is 

done for SIP revisions and for transportation conformity. Colorado Air Quality Control Commission 

Regulation 3 (Stationary Source Permitting and Air Pollution Emission Notice Requirements) 

requires stationary sources to predict the effect of air pollutants in attainment areas. Regulation 3 

also details the State of Colorado’s program regarding permitting as related to air quality modeling 

and data handling in predicting the effect of emissions of a pollutant with an established NAAQS.

Regulation 3 Part A, Section VIII "Technical Modeling and Monitoring Requirements" states that 

all estimates of ambient concentrations required under Regulation 3 shall be based on the applicable 

air quality models, data bases, and other requirements generally approved by EPA and specifically 

approved by the Division. Part A also requires all modeling data used to determine compliance to be 

appropriate given the topography, meteorology and other characteristics of the region.

The Modeling, Meteorology, and Emission Inventory Unit within the Division performs and 

reviews air quality impact analyses for a variety of programs, including state implementation plan 

revisions, transportation conformity determination, stationary source permitting, environmental 

impact statements, and hazardous waste site studies. The analyses include modeling, meteorological 

analysis, and emission inventory development for mobile sources and area stationary sources such 

as woodburning. The unit also performs air quality forecasting for the Denver-area High Pollution 

Season, open burning, and for special air quality studies. Additional information regarding these 

programs and authority is provided below. Some of these programs are found in the SIP. For 

example, both Colorado Air Quality Control Commission Regulation 4 (Woodburning) and the 

Denver PM10 SIP address State air quality modeling programs. 

PSD and Increment Consumption - Colorado's PSD program includes a requirement that the State 

periodically assess the adequacy of its plan to prevent significant deterioration of air quality. This is 

presented in Regulation 3, Part D, Section X.A.4. Part D also requires major sources to conduct air 

quality impact analyses for PSD increment consumption and for compliance with NAAQS. Part D 

also requires analysis of the impairment to visibility, water, soils, and vegetation that would occur as 

a result of the emissions of a regulated pollutant in significant amounts and general commercial, 

residential, industrial, and other growth associated with the source or modification.

SIP Development - Modeling is performed in the development and revision of State Implementation 

Plans, as needed or prescribed by the U.S. EPA, to ensure that specific areas of the state will 

maintain or re-attain compliance with the NAAQS in light of development and increased population 

and traffic.

Permits - The primary Colorado regulation for air quality permits is Colorado Air Quality Control 

Commission Regulation No. 3. Certain new/modified air pollution sources are subject to the 

regulatory modeling requirements in Regulation 3. Regulation 3, Part A, subsection VIII describes 

Colorado’s technical modeling and monitoring requirements. Modeling is often required to obtain a 

construction permit. 

The state submits data to the U.S. EPA as required under Regulation No. 3, Part D, Section VI.C. 

requiring the Division to transmit to the Administrator of the U. S. EPA a copy of each permit 

application relating to a major stationary source or major modification subject to this regulation, 
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and provide notice of every action related to the consideration of such permit.

Clean Air Act Section 110 (a)(2)(L) - Permitting Fees

The State of Colorado requires the owner or operator of a major stationary source to pay the 

Division any fee necessary to cover the reasonable costs of reviewing and acting upon any permit 

application. The collection of fees is described in Colorado Air Quality Control Commission 

Regulation 3. Specifically, Regulation 3, Part A. Section VI describes that each applicant required to 

obtain a permit must pay a fee, including the cost of permit review and relevant actions and that

stationary source owners or operators must pay an annual fee based on total emissions. The funds 

are used by the State to administer programs for the control of air pollution from stationary sources.

Clean Air Act Section 110 (a)(2)(M) - Consultation/Participation by Affected Local Entities

The Colorado Air Pollution Prevention and Control Act 25-7-105(1)(d), C.R.S. requires a

satisfactory process of consultation with general purpose local governments and any federal land 

manager having authority over federal land to which the state implementation plan applies, 

pertaining to transportation controls, air quality maintenance plan requirements, preconstruction 

review of stationary sources of air pollution, or any measure referred to in the PSD or the NNSR 

permitting programs, or granting delayed compliance orders pursuant to Section 25-7-118, C.R.S.

Colorado Air Quality Control Commission Regulation 3 provides for consultation and participation 

by local entities. Local governments receive notice and have the opportunity to comment on and 

participate in construction permit review procedures and operating permit application procedures 

under the provisions of Reg. 3, Part D. Section IV.A.1., “Public Comment Requirements.”

Local government coordination and consultation is also described in 25-7-128, C.R.S. which covers 

local government’s authority to enact air pollution resolutions or ordinances, standards and 

regulations, their submission and enforceability as part of the SIP, and the coordination of air 

pollution plans and programs between the state and local governments.

Colorado Air Quality Control Commission Regulation 10, “Transportation Conformity,” defines the 

criteria the Colorado Air Quality Control Commission uses for transportation conformity 

determinations to develop SIP revisions in non-attainment areas. Interagency consultation 

requirements are detailed in Reg. 10, and meet the federal requirements under 40 CFR 51.390, as 

published on August 15, 1997 (62 FR 158).

The Colorado Air Quality Control Commission holds a public hearing before adopting any 

regulatory revisions to the SIP. Local political subdivisions may participate in the hearing. The 

requirements for public hearings, including public notice of hearings, are established in 25-7-110, 

C.R.S. that describes the procedures to be followed in setting standards and regulations.