# STATE OF COLORADO

Bill Ritter, Jr., Governor James B. Martin, Executive Director Dedicated to protecting and improving the health and environment of the people of Colorado 4300 Cherry Creek Dr. S. Laboratory Services Division Denver, Colorado 80246-1530 8100 Lowry Blvd. Phone (303) 692-2000 Denver, Colorado 80230-6928 TOO Line (303) 691-7700 (303) 692-3090 ColoradoDepartment Located in Glendale, Colorado ofPublicHealth http://www.cdphe.state.co.us andEnvironment

June 18, 2009 Carol Rushin Acting Regional Administrator US EPA Region VIII 1595 Wynkoop Street Denver, CO 80202-1129 DearMs. Rushin: The Interstate AirPollutantTransport State Implementation Plan (SIP) is submitted to EPA for final approval and incorporation into the Colorado State Implementation Plan. Two copies ofthe materials needed for yourreview ofeach action are included withthis letter. On December 12,2008,the Colorado Air Quality Control Commission (AQCC) adopted a proposal to revise the ozone interstatetransportelement ofthe State Implementation Plan to address outstanding issues that EPA had identified with the original plan adopted by the AQCC in February 2007. This plan for the 1997 eight-hour Ozone Standard supersedes the first two elementsofthe SIP adopted by the AQCC and submittedJune 11,2008. The Interstate Transport SIP forthe 1997 eight-hour Ozone Standard submitted with this letter addresses part of the CAA Section II0(a)(2)(D)(i) provisions. The attached SIP addresses the elements covered by CAA Section IIO(a)(2)(D)(i)(I): significant contribution to nonattainment and interference with maintenance in another state. We understand that EPA intends to issue new guidance addressing thetwo elements, PSD and visibility, covered by Section 1IO(a)(2)(D)(i)(II). Upon EPA's issuance ofthe new guidance, the state will prepare the remainder of the SIP. We look forward to yourtimely review and approvalofthisrequest. The AQCC office may submit any additional technical support documentation orinformation thatyou may need for review directly tothe EPA. Should there be any questions regarding these materials, please contactthe AQCC office at 303-692-3478. Thank you. Sincerely, 

# RECEIVED JUN 23**2C~9** 

# USEPARNSOFFICE

# InterstateAirPollutant Transport State Implementation Plan

ADMINISTRATIVE MATERIALS Copies ofthe following administrative materials are included inthis submittal ofrevisionsto Interstate Air PollutantTransport State Implementation Plan. Hearingheld on December 11 & 12,2008.

• HearingNotice and Proposed Language as Published in the CCR • Meeting Agenda where Public Hearing Occurred andNoticepublished in the Legal Ads ofthe DenverPost • Procedural Documents ofthe Commission (this includes the AgendaItem Control Sheet, the Memorandum ofNotice, the Economic ImpactAnalysis) • Parties Hearing Documents (this includes a list ofthe parties, the parties prehearing statements and rebuttal statements, and any orders by the Commission

- - do not include all the attachments from theparties) • EPA Comments • Public Comments • Adopted Statement ofBasis, Specific Statutory Authority and Purpose • Adopted Languageby the Commission (inredline & footer noting adoption date and page numbers) • Final AdoptionNotice • Opinion ofthe Attorney General • Regulation as publishedin the CCR(this is the version that is publishedby Lexis Nexis)

# HearingNotice and ProposedLanguage as Publishedinthe CCR

# STATE OF COLORADO

Bill Ritter, Jr., Governor James B. Martin; Executive Director Dedicated toprotecting and improving the health and environment ofthe people ofColorado COLORADOAIR QUALITY CONTROL COMMISSION httpJ:wv.w.cdphe.state.co.us EDO-AQCC-A5 4300 Cherry Creek Drive South Denver, Colorado 80246-\530 Phone (303)692-3100 Colorado Department Fax (303) 691-7702 ofPublic Health TOO (303) 691-7700 and Environment 

### NOTICE OFPUBLIC RULEMAKINGHEARING BEFORE THE COLORADOAIRQUALITY CONTROLCOMMISSION Regardingproposed revisions to: 

### AmbientAir Quality StandardsRegulation, Regulation Numbers 3, 7, and 11 for the DenverMetropolitan &North FrontRangeArea OzoneAction Plan SUBJECT: The Air Quality Control Commission will consider aproposal from the DenverMetropolitan Area's Regional Air Quality Council, theNorth Front Range Transportation & Air Quality Planning Council and the Colorado Department ofPublic Health and Environment Air Pollution Control Division to adopt an ozone actionplanfor the DenverMetropolitan andNorth Front Range 8-hour ozone nonattainment area. The ozone actionplanproposes to reduce ambient ozone concentrations inthe nine county areato meetthe requirements ofthe national ambient air quality standard for ozone averaged over an 8-hourperiod and to address the directive of Governor Ritter to further reduce ambient ozone concentrations. The ozone action plan proposes to make revisions to the AmbientAir Quality Standards regulation to include mobile source emissionbudgets for the 8-hourozone nonattainment area for purposes ofconducting transportation conformity analyses. The ozone actionplanproposes to revise Regulation Number 3 and RegulationNumber 7to include additional emissionreduction, record keeping and emissionreportingrequirements for stationary sources ofvolatile organic compounds and for oxides ofnitrogen in the nonattainment area and on a statewidebasis. The proposed ozone action plan would make revisions to RegulationNumber 11 to require the implementation ofa vehicle emissions inspectionprogram in the North Front Range portionofthe 8-hour ozone nonattainment area and would include a March 2008 action ofthe Commission to revise the tailpipe emission standards for the program in the State Implementation Planto make it federally enforceable. The ozone actionplanproposes to include some ofthe proposed newrequirements in the federally enforceable State Implementation Plan and wouldretain some ofthe new requirements exclusively for state enforcement only. The ozone actionplanproposes to modify the provisions ofthe InterstateAir Pollutant Transport State Implementation Plan element adopted by the Commissionin February 2007, bynoting that the proposed maintenance plan would preventthe Colorado Front Range from contributing significantly to ozone non-attainment

Page 1of4or interfere with long-term maintenance ofthe national ozone standard in any other state. The ozone action planproposesto make typographical, grammatical and formatting revisionsto the above identifiedregulation's. FEDERAL REQUIREMENTS: Thefederal act requiresthe adoption ofa State Implementation Plan elementwith accompanying rules andrequirements to demonstrate compliance withtheNational AmbientAirQuality Standardfor ozone averaged overan 8-hourperiod andthe associatedtechnical support documentationto make that demonstration. A proposed Statement ofBasis, Specific Statutory Authority, and Purpose and a regulatory analysis (ifone has beenrequested) will be available for inspection no laterthanfive (5) days priorto the hearing. The language ofthe proposed rule revisions is attached to and made a part ofthis notice. HEARING SCHEDULE: DATE: December 11,2008 TIME: 9:00 AM PLACE: Colorado Department ofPublic Health & Environment 4300 Cherry CreekDrive South, SabinConference Room Denver, Colorado 80246 The hearingmaybe continuedatsuchplaces andtime as the Commission mayannounce. Interestedparties may contact the Commission Office at 303-692-3476to confirm meetingdates andtimes. PUBLIC COMMENT: The Commissionencourages all interestedpersonsto provide theirviews eitherorally atthe hearing orin writing priorto or atthe hearing. The Commissionespecially solicits comments and analyses from persons who will incurdirectly some cost orbenefit from the proposed revisions. Public testimony will betaken as close tothe start ofthe hearing as possible and duringthe hearing as necessary. Written and/orelectronic submissions priorto the hearing are requestedto allowreview priortopresentation atthe hearing. Written and/or electronic submissions shouldbe mailed to the Commission Office atleast 14dayspriorto the hearing. PARTY STATUS: In orderto obtainparty status at the hearing, compliance with several requirements as defined in the Commissions Procedural Rules is necessary. A petitionforparty status mustbe filed by electronic mail withthe Office ofthe Air Quality Control Commission no laterthan close of business on October 15, 2008. Thepetition must: 1) identifYthe applicant; 2)provide the name, address, telephone and facsimile numbers, andemailaddress of the applicants representative; and3) brieflysummarize what, 

### if any, policy,factual, andlegal issues the applicant has with the proposal(s) as of the time offilingthe application. Electronicallymailed copiesmust also be received, bythis same date, bythe Division staffperson and the AssistantAttorneys General representingthe Division and the Commissionidentified below. Anypersonmaypetitionthe Commissionto file documents inpapercopy format ifthey are unable for any reasonto not comply withthe requirements of 1.3.8(2) ofthe CommissionsProcedural Rules. Anoriginal and a specified number ofpapercopies must be filed inthe Office ofthe Air Quality Control

Page 2 of4Commission, Colorado Department ofPublic Health and Environment, 4300 Cherry Creek Drive South, Denver, Colorado 80246. Individuals may also obtainparty status throughthe submittal ofan initial alternative rule to the proposed rule. The submittal ofan alternative proposal must be accompanied by an electronic copy ofthe initial alternative proposedrule and all other associated documents as requiredby the Commission'sprocedural rules and mustbe filed by electronic mail with the Office ofthe Commissionby the date specified for party status requests. Initial alternative rules must also be filed by electronic mail with the Division staffperson and with each ofthe Assistant Attorneys General. Air Quality Control Commission Air Pollution Control Division Theresa L. Martin Mike Silverstein EDO-AQCC-A5 APCD-Bl 4300 Cherry Creek Drive South 4300 Cherry Creek Drive South Denver, CO 80246 Denver, CO 80246 Theresa.Martinrmstate.co.us Mike.Silverstein(a),state.co.us Jerry Goad Thomas Roan Attorney for the Commission Attorney for the Division Attorney General's Office Attorney General's Office 1525 Sherman St., 5th Floor 1525 Sherman St., 5th Floor Denver, CO 80203 Denver, CO 80203 Jerr)'.Goad(a),state.co.us Tom.Roanrmstate.co.us Requests received beyond the above stated deadline shall onlybe consideredupon a written motion for good cause shown. The Commissionreserves the rightto deny party status to anyone that does not comply withthe Commission's procedural rules. STATUS CONFERENCE: A status conference will be held October 

### 17,2008 at 

### 9:00 a.m., at the Department ofPublic Health and Environment to ascertain and discuss the issues involved, and to ensure that parties are making all necessary efforts to discuss and resolve such issues priorto the submission of prehearing statements. Attendance atthis status conference is mandatory for anyone who has requested party status. PREHEARING CONFERENCEIPREHEARING STATEMENTS: Attendance atthe prehearing conference is mandatory for all parties to this hearing. A prehearing conference will be held November 

### 17,2008 at 

### 1:00 p.m. in the Commission Offices at4300 Cherry Creek Drive South, Denver. All partiesmust submit by electronic mail a prehearing statementto the Commission Office byclose ofbusiness November 

### 13,2008. In addition, electronically mailed copies ofthese documents must be delivered by thatdate to all persons who have requested party status. A copy ofthe prehearing statement must also be electronicallymailedto the Divisionpoint ofcontactand each ofthe Assistant Attorney's General identified above by close ofbusiness November 

### 13, 2008. Any exhibit included in the prehearing statements will be electronically mailed to individual Commissioners for reviewprior

Page 3 of4to the hearing, providedthe party files electronic copies ofsuch exhibit. Rebuttals to the prehearing statementmay be submittedto the Commission Office and all otherpartiesby close ofbusiness November25, 2008. EXCEPTIONSTOFILE DOCUMENTS BYELECTRONIC MAIL The Commission's Procedural Rules provide for an exceptionto file documents by electronic mail. Ifgranted an exceptionto electronic filing pursuantto the provisions of 1.3.8(3) ofthe Commissions Procedural Rules, the applicant for party status shall file an original and fifteen copies ofthe prehearing statement inthe Office ofthe Air Quality Control Commission, and shall also deliver copies to each otherparty, applicantfor party status, the Assistant Attorneys General representingthe Commission and Division, and the Division staffpersonfor the proceedings, by electronic mail or as otherwise providedby the exception granted under Subsection 1.3.8(3), bythat same day. STATUTORYAUTHORITYFORTHE COMMISSION'S ACTIONS: The Commissionpromulgates these regulatory changes pursuantto its authority to 25-7-101, 25­ 7-103,25-7-105.1,25-7-109,25-7-110.5,25-7-110.8, 25-7-301 and 42-4-306, C.R.S. The rulemakinghearing will be conducted in accordance with sections 24-4-103 and 25-7-110, C.R.S., as amended, the Procedural Rules ofthe Commissionand as otherwise stated inthis notice. This list ofstatutory authority is not intended as an exhaustive list ofthe Commission's statutory authority to act inthis matter. Datedthis 25th day ofSeptember 2008 at Denver, Colorado
Colorado Air Quality Control Commission

Douglas A. Lempke, Administrator

Page 4 of4

# Meeting Agendawhere Public Hearing Occurred and Noticepublished inthe Legal Ads ofthe DenverPost

# STATE OFCOLORADO

Bill Ritter, Jr, Governor James B. Martin, Executive Director COLORADOAIR QUALITY CONTROL COMMISSION http:·wwwcdphe.state.co.lls 4300 Cherry Creek Drive South OED-OLRA-A5 Denver, Colorado**80246~** 1530 Phone (303) 692-3100 Colorado Department Fax (303) 691-7702 ofPublic Health TOO (303) 691-7700 and Environment 

# Notice ofMeeting andAgenda Air QualityControlCommission December11-13& 

# 19,2008

Colorado DepartmentofPublic Health & 

## Environment 4300 Cherry CreekDrive South, SabinRoom Denver, Colorado

Call to Order: Public Comment:

Agenda Review: 

### DECEMBER 11-13, 2008 9:00 AM

Determination ofa Quorum The public is invited to comment on any air pollution issue not on the agenda. The Commission will not take action on issues discussed under this agenda item today; however, items may be scheduled for further discussion or action. The Commission Administrator will reviewthe meeting agenda and discuss any proposed revisions to the agenda for the Commission's consideration.RULEMAKING HEARING 

### 1. DenverMetropolitan and North FrontRangeArea OzoneAction Plan (l0.5 hours presentation, 11 hours discussion) The Regional Air Quality Council, the North FrontRange Transportation and Air Quality Planning Council and the Division will presentto the Commission a proposed 8-hour ozone attainmentplan and accompanying regulations; RegulationNumbers 3, 7, 11 and the Ambient Standards Regulation, to revise the State Implementation Plan as well as state only regulatoryrequirements to reduce ozone precursor emissions and demonstrate compliance withthe 8-hourozoneNational AmbientAir Quality Standards and to address the September2007 directive ofthe Governorto worktoward attainment ofthe newly revised 8-hour ozone standard.



### DECEMBER 19, 2008 9:00AM

Call to Order: Determination ofa Quorum 

### Approval ofMinutes: Review/Approval ofthe October 16,2008 and November 20 & 21, 2008 meeting minutes ofthe Air Quality Control Commission. 

### PublicComment: The public is invited to comment on any air pollution issue not on the agenda. The Commission will not take action on issues discussed under this agenda item today; however, items may be scheduled for further discussion oraction. 

### Agenda Review: The Commission Administrator will reviewthe meeting agenda and discuss anyproposed revisions to the agenda for the Commission's consideration.
PUBLIC HEARING 

### 1. DenverRegional Council ofGovernments (DRCOG) Conformity (20 minutespresentation, 20 minutes discussion) The DRCOGwill presentto the Commission its anticipated Transportation Conformity findings regarding the 2035 Regional Transportation Plan and 2008/2013 TIP.
RULEMAKING HEARING 

### 2. Regulation Numbers 3 - BART (110 minutes presentation, 60 minutes discussion) The Commission will hold a public rulemaking hearing to consider a proposal from the Divisionto revise the regulation by adding BestAvailable Retrofit Technology (BART) Requirements to the rule for the Colorado Springs Utilities Martin Drakeunits 5, 6 and 7 and the CEMEX Lyons Cementplantregarding emission controls for sulfur oxides, nitrogen oxides, and particulates. This rulemaking activity will also be anupdate to the State Implementation Plan for Regional haze.
23. Regulation Number 9: Smoke Management Distribution ofCostUpdate (30 minutes presentation, 30 minutes discussion) The Divisionwill present to the Commissionproposed changes to RegulationNumber9, Appendix C regarding the distribution ofthe program's costto its permitteesbased on recent activity data. BRIEFINGS, DISCUSSIONS AND REpORTS 4. Commissioner Informational Items Commissioners will discuss among themselves activities that they have participated in over the past monththat they believe other Commissioners and/ormembers ofthe public may be interested in hearing about. 5. Division Director's Report

- Paul Tourangeau Monthly activities report 6. Attorney General's Report

- Jerry Goad Update ofany recent court actions on air quality issues 7. Administrator's Report - Doug Lempke January meeting agenda items review Adjourn

3

### The Denver Newspaper Agency DENVER,CO PUBLISHER'S AFFIDAVIT 

### City and County ofDenver, STATE OF COLORADO, SS

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.. .. . . .. .Jean Birch being of lawful age and being first duly awom upon oath, depo.e. and .ay.:
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.. am.nd.d and approv.d March 30, 1e23; And

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# Procedural Documents ofthe Commission

- AgendaItem Control Sheet

- Memorandum ofNotice

- Economic Impact Analysis (initial and final)

- Proposed SIP (narrative)

### COLORADO AIR QUALITY CONTROL COMMISSION AGENDA ITEM CONTROL SHEET
Item Title: Revisions to Regulation Number 7 and Regulation Number 3. Parts 

### A. Band C for Incorporation into the State Implementation Plan (SIP) Meeting date:

__.;::;S=ea:.;pt=e..:.:.m.:.:;:b"""e-,-r**~1.:.8!r...::2=0:..;:0:.=8**
TYPES OF ACTION NON-HEARING ACTIONS REQUESTFOR HEARING HEARING Administrative Public Rulemaking

_ Public Rulemaking



# -

_ Briefing Informational Informational



### - 

# -

_ Policy _Area Designations
RECOMMENDED ACTION _Adoption lApproval Denial



### - MOTION 

## --X Required Attached

_ Not applicable



### -
STATUTORY AUTHORITY General Specific

__.....;X:..:,

EPA SUBMITTAL Is this issue considered a SIP revision? Yes X No

_**---=-~** Which SIP? Ozone Reporting and Permitting Elements Date of EPA submission deadline: July 2009

Proposed Regulations 3 and 7 

### sip Revisions 

### 1 9/2/08ISSUE: The Colorado Departmentof Public Health and Environment, Air Pollution Control Division ("Division"), in coordination with the Regional Air Quality Council (RAQC) and the Northern Front Range Metropolitan Planning Organization (NFRMPO) as the Lead Planning Agencies, requests that the Colorado Air Quality Control Commission ("Commission") revise the requirements setforth in Regulation Number 7 and Regulation Number3, to address ozoneformation in the 8-hourozone non-attainmentarea (a.k.a. the 9-county DenverMetroArea/North Front Range (DMAIMFR) Non-AttainmentArea (NM)) and state-wide. Specifically, the Division's proposed revisions serve to reduce volatile organic compound (VOC) emissions, an ozone precursor, and thus reduce ozone concentrations in ambientair. These revisions are necessaryto ensure attainmentwith the current 8-HourOzone NationalAmbientAirQuality Standard (NMQS)setat0.08 parts per million (ppm), and to otherwise achieve ozone reductions in light of both the new 8-hour Ozone NMQSset at0.075 ppm and the Governor's July27,2007directiveto proactively and pragmatically reduce ozone levels. Also, the Division is proposing revisions to Regulation Number 3 to revise Air Pollution Emission Notice (APEN) reporting requirements to improve the Division's emissions inventory, to facilitate planning for developmentofadditional emissions reductions strategiesthat may be neededto meetthe Environmental ProtectionAgency's newozone NMQS,that lowersthe standardfrom 0.08 ppm to 0.075 ppm. Specifically, the Division requests that the Commission set for public hearing the proposed revisions to Regulation 7 as follows: • change the title to identify NOx in addition to VOC as an ozone precursor, • modify the emission and add monitoring control requirements applicable to condensate storage tanks at oil and gas exploration and production operations, natural gas compressor stations and natural gas drip stations located in the 8-Hour Ozone Non-attainmentArea (Regulation 7, Section XII), • set newemission control requirements for pneumatic controllers associated with oil and gas operations located in the 8-HourOzone Non-attainmentArea (Regulation 7, Section XIII), • expand the applicability of Reasonably Available Control Technology (RACT) requirements to existing, newand modified sources in ozone non-attainmentareas outside ofthe historic 1-hourOzone Non-attainmentorattainment/maintenancearea (Regulation 7, Sections I-XVIII), • make clarifications orcorrections as identified (Outline ofRegulation and Sections II, VI, VII), and • make typographical, grammatical and formatting changes, as necessary. Additionally, the Division requests that the Commission adopt proposed revisions to Regulation 3 to revise APEN reporting exemptions for specific source categories (Regulation 3, Part A, Section 

### 11.0., Part B, Section 

### 11.0., and Part C, Section II.E.).
I. Background Proposed Regulations 3 and 7 SIP Revisions 9/2/08 

### 2State and regional agencies in the Denver metropolitan area entered into a voluntary agreement with the U.S. Environmental Protection Agency (EPA) in December 2002 that laid out a process for achieving attainmentwith EPA's 1997 8-hour National Ambient Air Quality Standard (NAAQS) for ozone of0.08 ppm in an expeditious manner. Called an Early Action Compact for Ozone (lithe EAC"), the agreement set forth a schedule for the development oftechnical information and the adoption and implementation ofthe necessary control measures into the state implementation plan (SIP) in order to comply with the 0.08 ppm 8-hour standard by December 31, 2007 and maintain the standard beyond that date. The EAC Ozone Action Plan (SIP) was submitted to EPA summer 2004. EPA promulgated approval ofthe Ozone Action Plan in the Federal Register (Vol. 70, Number 94, May 17, 2005). A revision to the Ozone Action Plan to preserve the reductions estimated in the original plan was approved by the Air Quality Control Commission on December 17, 2006 and the Colorado State Legislature in spring 2007, and submitted to the EPA in February 2008. Based on the 2001-2003 design values, the DMAlNFR 8-hour ozone control area violated the 8-hour ozone standard at three monitors. In April 2004, EPA designated and classified areas ofthe country that violated the 8-hour standard. At that time, based on the EAC, the EPA deferred a DMAlNFR non-attainment area designation. The DMAlNFR deferred non-attainment area failed to achieve the standard due to high readings in July 2007 which resulted in a 3 year (2005-2007) Design Value of0.08 ppm at one monitor (Rocky Flats North) which violated the 8-hour ozone NAAQS. The EPA's deferral ofa nonattainment designation for the area expired on November 20, 2007, signifying that the area is now considered nonattainment, or in violation ofthe 1997 eight-hour ozone NAAQS of0.08 ppm for ground level ozone. The DMAlNRFA includes all ofAdams, Arapahoe, Boulder, Broomfield, Denver, Douglas, and Jefferson Counties as well as portions of Larimer and Weld Counties. This area is now known as the Denver Metro Area/North Front Range Non-Attainment Area. Pursuant to the Federal Clean Air Act, Colorado must prepare and submit to EPA a State Implementation Plan (SIP) no later than June 30, 2009. This plan must propose measures designed to reduce ground level ozone as necessary. These emission reductions must be sufficient to ensure that ozone is reduced to below the eight-hour NAAQS no laterthan 2010. IfColorado fails to submit a SIP by the deadline, the Clean AirAct mandates that the EPA prepare and implement a Federal Implementation Plan. The Colorado General Assembly has mandated that the Commission adopt such measures as are necessary to ensure compliance with the NAAQS. The Commission has adopted these rules to carry out this mandate. Photochemical grid dispersion modeling indicates that without further emission controls, Colorado will attain the eight hour standard by 2010. The dispersion modeling reflects that Colorado would attain the standard by a narrow margin
- within 0.001 ppm on a standard of 0.08 ppb. Photochemical dispersion modeling analysis is the primary tool Proposed Regulations 3 and 7 SIP Revisions 9/2/08 

### 3used to assess present and future air quality trends, and is required for EPA to approve the state attainment demonstration in the SIP. dispersion modeling results have an inherent level of uncertainty, as recognized in EPA guidance, and it is appropriate for a state to use other tools at its disposal, including further control measures, to address and mitigate any uncertainties that can be present in dispersion modeling. It is appropriate for the state to use such tools to increase the confidence in and other wise ensure that the predicted modeling results are accurate and borne-out in future air quality monitoring demonstrating attainment with the 8-hour standard. In addition, pursuant to EPA guidance, if modeling results indicate thatthe highest ozone levels will fall between 82 and 87 ppb, Colorado must conduct a "weight ofthe evidence" analysis and other supplemental analysis in order to corroborate the modeling results. Colorado's model results are within this range, and thus the state has conducted this analysis. The analysis supports the conclusion that Colorado will attain the standard by 2010, although by a narrow margin. To increase the certainty ofthe model results and the Weight of Evidence demonstration, the Commission concludes that these additional control measures are necessary to carry out its mandate to adopt a SIP that contains those elements that are necessary to assure attainment ofthe ozone NAAQS. Further, contrary to past ozone formation reductions in the DMAlNRFA, modeling has indicated that NOx reductions, in addition to VOC emissions reductions are beneficial in reducing ozone in the same area. The Division's meteorological analysis supports this conclusion. Thus, the Commission has adopted ozone reduction strategies that include both VOC and NOx emissions reductions. Modeling and supplemental analyses indicate that measures designed to reduce these precursors will be most effective in reducing ozone. The Division proposes to adopt additional controls for condensate tanks and pneumatic controllers located within the current ozone nonattainment area (the DMAlNFR). These revisions are based on reasonably available emission control techniques. All validated, reviewed and sound scientific methodologies made available by interested parties have been considered. Evidence in the record supports the finding that the rule shall result in a demonstrable reduction in ozone, and will reduce the risk to human health and the environment, and otherwise provides benefitsjustifying the costs. Among the options considered, the regulatory option chosen will maximize the air quality benefits in the most cost-effective manner. Condensate tanks are non-pressurized vessels installed at oil and gas facilities to store condensate, a petroleum product that is classified as a volatile organic compound (VOC), a ground level ozone precursor pollutant. Pneumatic controllers are natural gasactuated instruments used at oil and gas facilities. These instruments emit VOCs when the controller is actuated by pressurized natural gas and the associated volume of natural gas is bled to the atmosphere. VOCs are also emitted through the venting of associated valves, howeverthese emissions are believed to be minimal.
Proposed Regulations 3 and 7 SIP Revisions 9/2/08 

### 4Reasonably Available Control Technology (RACT) requirements of Regulation 7 are proposed to be expanded such that they apply generally to any ozone non-attainment or attainment maintenance area, and not specific one-hour or eight-hour ozone nonattainment areas or early action compact areas. Additionally, there are two types of RACT required in Regulation 7 those developed by the state to address ozone and control technique guidelines (CTGs) which are developed by EPA. The CTGs must apply to all ozone non-attainment areas. The control technology requirements of Regulation 7 are proposed to be clarified in howthey interact with Regulation 3, Part B, Section 11.0.2. The Division proposesto adoptthefollowing revisionsto Regulation 7to ensure attainment with the current eight-hourozone NAAQS setat 0.08 ppm, and to achieve additional ozone reductions in light of both the new eight-hour ozone NAAQS set at 0.075 ppm and the Governor's JUly 27, 2007 directive to proactively and pragmatically reduce ozone levels.


### II. Proposed Rule The Division's proposed revisions to Regulations 3 and 7 are part of an overall ozone reduction strategy to be incorporated into the Colorado SIP. The Division believes this strategy accomplishes five objectives: A) reduce 

## vac emissions from oil and gas operations in the ozone non-attainment area, B) revise the control requirements for condensate tanks by transitioning from a system-wide to an emissions threshold control strategy in the ozone non-attainment area, C) expand

## vac RACT requirements such that all ozone non-attainmentareas aresubjectto Regulation 7's RACT requirements, D) clarify howthe RACT requirements in Regulations 3 and 7 interact in the ozone non-attainment area, E) improvethe Division's inventory ofspecificsource category emissionsstate-wide; and F) make typographical, grammatical and formatting changes for greater clarity and readability.


### A. Reduce

## voe Emissions from Oil and Gas Operations in the Ozone Non-attainmentArea The proposal requires: 1) additional

## vac emissions reductionsfrom condensate tanks in any ozone non-attainment area compared to the established control requirements identified in Regulation 7, Section XII., and 2) sets new 

## vac control requirementsfor pneumaticcontrollers in any ozone non-attainmentarea in Regulation 7, Section XIII.

.Condensate Storage Tanks The Division's proposal revises current condensate storage tank control requirements in Regulation 7, Section XII by reorganizing the rule, adding/revising definitions, setting additional control requirements for tanks, transitioning awayfrom a system-wide control strategyto an emissionthreshold control strategy, adding monitoring requirements, and revises recordkeeping and Proposed Regulations 3 and 7 SIP Revisions 9/2/08 

### 5reporting requirements.
The Division proposes that tanks serving newly drilled, recompleted or stimulated wells be required to employ air pollution control equipment during the first 90 days ofproduction. Air pollution control equipment can include combustion devices, vapor recovery units, or Division approved alternative controls or pollution prevention activities that meetthe control efficiency requirement. Ifafterthe first 90 calendar days, the data shows that annual emissions from the tank will not exceed APEN reporting thresholds, the control may be removed. This requirement is designed to address the facts that production, and thus emissions, are greatest during the period immediately after drilling, recompletion or stimulation, and that the actual production/emission level is not known priorto drilling, recompletion or stimulation. Accordingly, significant

## vac emissions may occur before it can be determined whether a tank will need to install controls in accordance with the annual emission threshold requirement. By requiring controls on all tanks serving newly drilled, recompleted or stimulated wells, the proposed rule eliminates emissions during the initial period, while allowing owners and operators to remove controls after they can determine that emissions will not exceed the 2 ton per year threshold.
The Division proposes enhanced monitoring provisions for condensate tanks as an indicator ofcompliance to ensure actual emissions reductions occur. The Division believes it is appropriate to require the installation and operation ofauto-igniters and electronic surveillance for each combustion device. In many cases, condensate tanks are remotely located and un-manned. Autoigniters may be relied on to identify when the pilot is not lit and attempt to relight it, and ensure control operation. Electronic surveillance may be relied upon to documentthe duration oftime when the pilot is not lit, and notify an operatorthat repairs are necessary to ensure proper control operation. In an effortto offset the added control operation assurance gained through enhanced monitoring, the Division proposed to minimize the requirements for emissions recordkeeping and reporting. This revision reduces the frequency and reporting ofemissions estimation calculations, from a weekly to a monthly basis and from annual company-wide reporting to reporting upon request ofthe Division (normally during routine inspections or via APEN updates for significant increases in annual emissions). Emissions estimates are required to be maintained on a rolling-12 month basis.
The Division's proposed rule will lowerthe applicability thresholds for existing tanks from 20 down to ten tons per year ofactual uncontrolled

## vac emissions, beginning May 1, 2010. The control technology must reduce uncontrolled emissions by at least 95%. Affected tanks are required to Proposed Regulations 3 and 7 SIP Revisions 9/2/08 

### 6control emissions by 95% and to monitor associated air pollution control equipment to ensure compliance. Finally, this revision reorganizes the requirements for condensate tanks for clarity.
Pneumatic Controllers This revision establishes new VOC emission controls for pneumatic controllers in the 8-hour Ozone Non-attainmentArea in Regulation 7, Section XVIII. Pneumatic controllers are widely used in the oil and gas industry, to control or monitor process parameters such as liquid level, gas level, pressure, valve position, liquid flow, gas flow and temperature. Pneumatic controllers are instruments that are actuated by natural gas pressure (some natural gas may be bled to the atmosphere from the pneumatic controller and some may be vented from the associated valve). 

## vac emissions reductions from pneumatic controllers are specific to the bleeding of natural gas from the controller and not the venting from the valve, which is thought to be minimal. High-bleed controllers emit more than six standard cubic feet per hour (scth) of natural gas to the atmosphere, and low-bleed controllers emit less than or equal to six scfh of natural gas to the atmosphere. The oil and gas industry has already begun replacing high-bleed controllers with low-bleed controllers, understanding the financial gain of minimizing the bleed rate of pneumatic controllers and keeping the natural gas in the pipeline. Underthis revision, most high-bleed controllers must be replaced with the equivalent of low -bleed or better pneumatic controllers by May 1, 2009. Pneumatic devices installed after February 1, 2009 must be replaced with the equivalent of low -bleed or better pneumatic controllers. There is an exception for high-bleed controllers that the sourcejustifies to the Division as necessary for safety 

### andlorprocess purposes. Operators must inspect and maintain high-bleed controllers on a monthly basis. Operators must also keep logs of the number of in-use high-bleed controllers, and the reason that each highbleed controller remains in place, and the inspection and maintenance ofthe in-use high-bleed controller. These revisions require operators to physically tag the in-use high-bleed controllers to enable the Division to track compliance. A 2003 EPA study reported that emissions from pneumatic controllers are collectively one ofthe largest sources of methane emissions in the natural gas industry. Estimated annual nationwide methane emissions are approximately31 billion cubic feet (Bct) from the production sector, 16 Bcffrom the processing sector, and 14 Bcffromthe transmission sector. As stated above, by definition, high-bleed pneumatic controllers emit more than six scfh of natural gas to the atmosphere. The highest bleed rate listed in one source, atable published bythe Proposed Regulations 3 and 7 SIP Revisions 

### 9/2/08 7

### EPA, is 42 cubic feet per hour (cfh). The average bleed rate for high-bleed pneumaticcontrollers in the NAA is 21 cfh. Natural gas is primarily composed of methane, but also contains vac emissions which are ozone precursors. Therefore, emission reductions related to this source category havethe potential to be significant.


### B. Transition from a System-wide to an Emissions Threshold Control Strategy in the Ozone Non-attainmentArea As discussed above, the current rule governing condensate tanks does not require controls at any specific unit, but instead requires asystem-wide reduction across all units. The theory behind this was to provide owners and operators with the flexibility to install controls where they saw fit. Because no particular unit had to be controlled, assessing compliance at any given point in time was close to impossible without an extremely extensive record-keeping system. In recognition of this, the current rule requires each company to maintain a spreadsheet listing all subjecttanks, production data and control data on adaily basis in order to verify compliance with the daily system wide reduction requirement. Additionally, the regulation requires companies to submit an annual system-wide report describing in detail how they complied with the emission reduction requirements. Maintaining this spreadsheet, and calculating daily emission reductions has proved to be a very challenging and laborintensive propositionfor industry (especially smallercompanies). Reviewing this data has also proved onerous for the Division. Finally, based on the Division's review ofthe data from 2005, 2006 and 2007, it appears that for the most part, owners and operators have chosen to comply with the regulation by controlling their largest emitting units. Accordingly, the flexibility inherent in the current system-wide approach lacks the anticipated utility, while at the same time imposing burdensome requirements on both the regulated community and the Division. To alleviate the burdens inherent in the current regulatory scheme, the Division proposes moving from a system-wide reduction requirement to an emission threshold control requirement, whereby any tank that emits a certain amount of vacswill be required to install and operate an air pollution control device. By eliminating the system-wide reduction approach, the daily spreadsheet and annual compliance report are unnecessary to determine compliance with the rule. Instead, the proposed rule requires companies to track condensate production from each tank and identify periodswhere a required control device is not operating. These records will allowthe Division to determine compliance at any given tank. The proposed rule does not require owners or operators to periodically submit these records to the Division, but does require that the records be maintained for a period ofthree years. The absence ofa reporting requirement on an annual basis is consistent with the reporting requirement of other minorsources acrossthe state. Moreover, the Division believesthat given the Division's broad information gathering authority under the Colorado Air Pollution Prevention and Control Act, the lack ofa reporting requirementwill not Proposed Regulations 3 and 7 SIP Revisions 9/2/08 

### 8impede the Division's ability to enforce the rule.
In addition to seeking additional VOC emissions controls, the Division believes that the proposed transition from the system-wide to an emissions threshold control strategy is necessary in order for the Division to easily determine the compliance status of a source. In addition, the threshold control strategy increases control requirements in that more tanks are required to be controlled (i.e. all new or modified tanks greaterthan 2 tons peryear).


### C. Expand and Clarify VOC RACT Requirements in the Ozone NonattainmentArea This proposal revises Regulation 7 to expand its application to all subject sources in any ozone non-attainment and attainment/maintenance areas. This regulation previously applied only to the One-hour Ozone NonAttainment Area. Accordingly, this regulation will apply to some sources that were previously outside of its geographic scope. These sources are not currently subjectto adopted Control Technique Guidelines (CTGs) orgeneral RACT requirements. This revision ensures equity across all designated ozone non-attainment areas, and complies with EPA's requirement that CTGs apply in all ozone non-attainment areas. Case-by-case RACT requirements ofSections I and II and general RACT requirements of Sections I and 111- XVIII do not apply consistently to all ozone non-attainment or attainment areas. Specific sections sometimes apply in the one-hour ozone non-attainment area, the eight-hour ozone control area, and sometimes state-wide. This revision expands Regulation 7's applicability to any ozone non-attainment or attainment/maintenance area. This is done intentionally to apply Regulation 7 requirements to current as well as any future ozone non-attainment or attainment maintenance areas in Colorado. It is possible, considering the current ozone NAAQS has been lowered from 0.08 to 0.075 ppm and the difficulties experienced in some areas in attaining the ozone NAAQS, that Colorado will have additional areas designated as being in non-attainment with the new ozone NAAQS. This revision also clarifies how the Regulation 3 RACT requirements interact with Regulation Number 7. Currently, Regulation 3, Part B, Section 111.0. requires all new and modified minor sources ofpollutants or precursors to pollutants for which the area has been designated as being in non-attainment or is currently in attainment/maintenance with a NAAQS to submit a RACT analysis and implement RACT. Further, Regulation 7 is currently unclear on whether existing sources that are modified (such that they have undergone a physical change or change in operation which causes an increase in emissions) become subject to new source requirements or not. This revision clarifies that existing sources that are modified are subject to the Regulation Proposed Regulations 3 and 7 SIP Revisions 9/2/08 9Number 3, Part B, Section II.D. requirements and are considered to be a new source for the purposes of Regulation 7. This revision also clarifies that the case-by-case RACT requirements of Regulation 7, Section II.C. only apply to existing, new and modified sources at which all air pollution generating activities at that source are already subject to RACT. 

### D. Clarify RACT Requirements in Regulations 3 and 7 in the Ozone NonattainmentArea Regulation Number 3, Part B, Section III.D. currently requires RACT in ozone non-attainment areas for all new and modified sources emitting VOC or NOx emissions and commencing construction on or after February 1, 2009. This revision specifies that pursuant to Regulation 7, Section II.C., all existing sources that emit 100 tons per year ofVOC emissions and that are located in the eight-hour ozone non-attainment area become subject to RACT. 

### E. Improve Emissions Inventory State-Wide The Division's proposal removes and/or revises several categorical APEN reporting and/or permitting exemptions in Regulation Number 3, Parts 

### A, Band C in order to improve the Division's emissions inventory and for the sake of equity. Proposed changes to exemptions fall in three categories: 1) specific APEN and permitting exemptions were removed altogether; 2) specific APEN exemptions were removed and permit exemptions were kept in place; and 3) specific APEN and permit exemptions were clarified, but kept in place. Remove APEN and Permitting Exemptions The currentAPEN and permitexemptionsfor condensatetanks were established using**~Iigher** de minimis levelsthan currently apply. Forexamplethe condensate storage tank exemptions listed under Regulation Number 3, Part A, Section II.D.1.eeee. and Part C, Section Il.e.3.gggg., based on 730 barrels ofproduction, was derived using a five ton per year VOC emissions de minimis level which appliesto attainmentareas, instead ofthe two ton per year de minimis level that applies to non-attainment areas. These current APEN and permit exemptions were established using higherde minimis levelsthan currently apply. This higher de minimis level for condensate tanks means that the Division has a limited inventoryofemissionsfrom condensatetanksthat emit lessthan thefive ton per year VOC de minimis level. Other source categories located in the 8-hour Ozone Non-attainmentArea are required to submit an APEN if actual uncontrolled emissions ofVOCs or NOx exceed one ton per year and obtain a permit ifactual uncontrolled emissions of VOCs or NOx exceed two tons per year. Thus, there is an issue of equity, allowing one source categoryto be treated differentlyfrom others. Additionally, the condensatetank exemption is based on astandardized emissionfactor, 13.7 pounds of VOC emissions per barrel of production, which may not be Proposed Regulations 3 and 7 SIP Revisions 9/2/08 10representative ofeach natural gas field. This APEN and permit exemption was removed. However, sources maystill make useofthe genericAPEN exemption, by determining that actual annual uncontrolled emissions fall below the applicable de minimis levels identified in Regulation Number 3, PartA. If based on this generic exemption, a source is determined to be APEN exempt, the source is also permit exempt. Remove APEN Exemptions, Keep Permit Exemptions Based on the Division's experience, actual emissions from several source categories are anticipated to be higher than previously believed. These categories are: petroleum industry flares (Regulation 3, Part A, Section II.D.1.m.), crude oil truck loading (Regulation 3, Part A, Section II.D.1.ee.), oil production wastewater (Regulation 3, Part A, Section II.D.1.uu.) and crude oil storage tanks (Regulation 3, Part A, Section II.D.1.ddd.). The Division wants to better understand the actual annual uncontrolled emissions from these categories, howeverthe Division has concernsthatthese source categories may trigger permitting requirements, and that the resulting permitting may require more Division resources than available. Thus, the Division's proposal is to removethe specificsource categoryAPEN exemptions
- with the understanding that sources may still make use ofthe genericAPEN exemption.
Revise APEN and/or Permitting Exemptions Based on the Division's experience, actual emissions from several source categories specificto oil and gas related operations are higherthan previously believed. Thus the APEN and permitting exemptions for surface water impoundments (Regulation 3, Part A, Section II.D.1.uuu. and Part C, Section II.E.3.yyy.) were revised to exclude from the exemption, oil and gas production wastewater (similarto Regulation 3, PartA, Section II.D.1.uu.). Also, theAPEN and permitting exemptions for chemical storage tanks (Regulation 3, Part C, Section II.E.3.n.) were revised to exclude oil and gas production wastewater or commercial facilities' operations (similar to Regulation 3, Part A, Section II.D.1.uuu. and Part C, Section II.E.3.yyy.). Finally, the APEN and permitting exemptions for fuel storage dispensing (Regulation 3, PartA, Section II.D.1.cccc. and Part C, Section II.E.3.cccc.)were revised to expand the applicability ofthe current exemption from specificallythe 1-hour Ozone Non-attainment or Attainment/maintenance Area to any ozone non-attainment area to ensure VOC controls are required in all ozone nonattainment areas.
F. Rule Reorganization and Other Changes The Division's proposal changes the title of Regulation 7 to include NOx. An outline of sections is provided to better understand contents of Regulation 7. Outdated sections are removed (Le. Section II.F.1. specific to Gates Rubber Company, which is now out of business). Section XII, specific to Proposed Regulations 3 and 7 SIP Revisions 9/2/08 11condensate tanks in the ozone non-attainment area is reorganized for clarity. One appendix (new Appendix A) is added to provide maps ofozone nonattainment areas and chronologies of attainment designations, ofwhich certain requirements key off. Finally, sections and appendices are renumbered and formatted as necessary.


### III. Conclusion The Division requests thatthe Commission modifythe requirements setforth in Regulations 3 and 7 to ensure future attainment with the current 8-Hour Ozone National Ambient Air Quality Standard (NAAQS) set at 0.08 ppm, and to achieve additional ozone reductions in light ofboth the new 8-HourOzone NAAQS set at 0.075 ppm and the Governor's July 27, 2007 directive to proactively and pragmatically reduce ozone levels.
ATTACHMENTS: 1. Memorandum of Notice 2. Regulation NO.7
- Proposed Language 3. Regulation Number7 StatementofBasis and SpecificStatutoryAuthority and Purpose 4. Regulation Number 3, Parts A, Band C - Proposed Language 5. Regulation Number 3, Parts A, Band C - Statement of Basis and Specific Statutory Authority and Purpose 6. Initial Economic ImpactAnalysis

Proposed Regulations 3 and 7 SIP Revisions 9/2/08 

### 12SIGNATURES:

Preparer: Theresa Amoroso Date

Supervisor: Dena M. Wojtach Date

Program Manager: Kirsten Linnea King Date

Division Director: Paul Tourangeau Date

Proposed Regulations 3 and 7 SIP Revisions 

### 9/2/08 13MEMORANDUM OF NOTICE

Date: September 18,2008 To: Colorado Air Quality Control Commission Subject: Proposed revisions to the Air Quality Control Commission's Regulation Number3 & Regulation Number 7; Regulation 7 Sections I, II, VI, VII, VIII, XII, XVII, and XVIII

GENERAL DESCRIPTION The Colorado Department ofPublic Health and Environment, Air Pollution Control Division ("Division"), in coordination with the Regional Air Quality Council (RAQC) and the Northern Front Range Metropolitan Planning Organization (NFRMPO) as the Lead Planning Agencies, requests thatthe Colorado Air Quality Control Commission ("Commission")revise the requirements set forth in Regulation Number 7 and Regulation Number 3, to address ozone formation in the 8-hour ozone non-attainment area (a.k.a. the 9-county Denver Metro AreaINorth Front Range (DMA/MFR) NonAttainment Area (NAA) and state-wide. Specifically,the Division's proposedrevisions serve to reduce volatile organic compound (VOC) emissions, an ozone precursor, and thus reduce ozone concentrations in ambient air. These revisions are necessary to ensure attainment with the current 8-Hour Ozone National Ambient Air Quality Standard (NAAQS) set at 0.08 parts per million (ppm), andto otherwise achieve ozone reductions in light ofboth the new 8-Hour OzoneNAAQS set at 0.075 ppm and the Governor's July 27, 2007 directive to proactively and pragmatically reduce ozone levels. Also, the Divisionis proposing revisions to Regulation Number 3 to revise Air Pollution Emission Notice (APEN) reporting requirements to improvethe Division's emissions inventory, to facilitate planning for development ofadditional emissions reductions strategies that may be needed to meet the Environmental Protection Agency's new ozone NAAQS, that lowers the standard from 0.08 ppm to 0.075 ppm. EXPLANATION OF PROPOSED RULES Specifically, the Division requests that the Commission set for public hearing the proposedrevisions to Regulation 7as follows:
• change the title to identify NOx in addition to VOC as an ozone precursor, • modify the emission control requirements applicable to condensate storage tanks at oil and gas exploration and production operations, natural gas compressor stations and natural gas drip stations located in the 8-Hour Ozone Non-attainment Area (Regulation 7, Section (XII) to: • Reduce VOC emissions,

### Revise the control requirements for condensatetanks by transitioning from a system-wide to an emissions threshold control strategy in the ozone non-attainment area, Owners or operators ofnew ormodified condensate storage tanks ortank batteries emitting 2tpy VOC must control VOC emissions by 95% beginning May 1,2009, Owners or operators ofexisting condensate storage tanks ortank batteries emitting 10 tpy VOC must control VOC emissions by 95% beginning May 1, 2010, and Condensate tanks serving wells that are drilled, stimulated orrecompleted after February 1, 2009 must control VOC emissions by 95% during the first 90 days from first production. Afterthe 90­ day period, control equipmentmay be removed ifuncontrolled actual emissions from condensate tanks are less than 2 tpy VOC. • Monitoring: Owners or operators ofcondensate tanks requiredto control VOC emissions must inspect ormonitorthe control equipment to ensure it is operating each time condensate is loaded out from the tank. • Recordkeeping: Owners or operators required of condensate tanks shall maintain monthly condensate production records, actual controlled and uncontrolled emissions, and when air pollution control equipment is not operating.
• set new emission control requirements for pneumatic controllers associated with oil and gas operations located in the 8-Hour Ozone Non-attainment Area (Regulation 7, SectionXIII), All new controllers (after February 1,2009)mustbe at least low­ bleed, All existing high-bleed controllers mustbe replaced with low­ bleedby May 1, 2009, and A safety and orprocess exemption for in-use high-bleed devices is available, howeverrecordkeeping and reporting requirements apply. • expand the applicability of Reasonably Available Control Technology (RACT) requirements to existing, new and modified sources in ozone non-attainment areas outside ofthe historic I-hour Ozone Non-attainment or attainment/maintenance area (Regulation 7, Sections I-XVIII),
• make typographical, grammatical and formatting changes for greater clarity and readability throughout Regulation 7, as necessary, and
• make clarifications orcorrections throughout Regulation 7, as identified: o 

### outline regulation, o 

### make corrections to definitions and corresponding numbering (II.AA.), o 

### add ozone non-attainment area definition (II.A.I7.) , o 

### delete regulations specific to Gates Rubber Plant because they no longer apply (Section II.F.),


### 2o Clarifyreporting requirement ofevery six months for operators ofEFR tanks (Section VI.B.2.c.(2)(B)(i)), and o Clarify the applicability ofSectionVII.A.2 to include sections XII and XVII. Additionally, the Divisionrequests thatthe Commission adoptproposed revisions to Regulation 3 to revise APEN reporting exemptions for specific source categories. This will improve the Division's inventory ofspecific source category emissions state-wide (Regulation 3, Part A, Section II.D., Part B, Section II.D., and Part C, Section II.E.).
MATERIALS TO BE INCORPORATED BY REFERENCE No materials will be incorporatedby reference in the proposed rule revisions. BACKGROUND ON DEVELOPMENT OF THE PROPOSED RULE Problem Statement Even at low levels, ground-level ozone can cause acute respiratory problems, aggravate asthma, cause significanttemporary decreases in lung capacity ofeven ofhealthy adults, cause inflammation oflung tissue and reduce the lung'scapacity to fight disease. There appears to be no "safe" inhalation level ofozone for humans. Itis evenmore toxic to plants, e.g. crops and natural flora, as well as destructive to rubber and othermaterials in the built environment. Ozone is formed when VOCs react withNOx and otherpollutants in the presence ofsunlight, especially on long, hot, sunny days. Therefore, the ozone season is designatedto be May through September. Numerous exceedances ofthe national 8-Hour Ozone Standard during 2003 broughtthe Colorado Ozone Control Areainto violation status for the 3-yearperiod from 2001-2003. In response, the Colorado Early Action Compact (EAC) was formed, which produced a federally enforceable Ozone Action Plan (approved by the Commission March 12,2004). The plan was designed to address VOC emissions quickly and avoid an EPA nonattainment designationfor the 8-hour ozone standard. The Commission initially adopted Section XII ofRegulationNumber 7 in Mach of2004 in connection with the EAC to defer an ozone non-attainment designation for the 8-Hour Ozone Control Area. However, VOC emissions in 2004 already far surpassedthe 2007 "cap." Therefore, the regulation was amended in December2006. As a result, SectionXII currently requires that owners and operators ofcondensatetanks in the 8-Hour Ozone Control Area achieve a 75% reduction in overall VOC emissions through 2011; beginning in 2012, 78%, as well as a 70% reduction during the non-ozone season. Becausethe regulation requires system-wide reductions and does not mandate reductions from specific units, it entails extensive recordkeeping and reporting to ensure compliance. Companies must maintain daily spreadsheets reflecting the total system-wide

3daily percentage reduction, identify eachtank subjectto the regulation, list daily condensateproduction for eachtank, list the emission factor for eachtank, identify the location and control efficiency for each condensate tank airpollution control device, and note any periods when control devices are not operating. Despite additional reductions obtained viaregulatory amendment, the national 8-Hour OzoneNational Ambient Air Quality Standard was exceeded in Summer2007. The 8­ Hour Ozone Control Area was designated as an EPA nonattainment area onNovember 20,2007. As a result, RegulationNumber7 is being proposed to be amended, as described in this document. How do proposed regulatory revisions help solve the problems? The proposed revisions would lead to VOC emissionreductions beneficial in achieving ozone formation in the non-attainment areato achieve attainment withthe ozone standard, thus bringing the area out ofnonattainment. How were proposed regulatory revisions developed? Ambient air monitoring data showedthat ozone levels in the 8-Hour Ozone Control Area exceededNAAQS by late Summer2007. Therefore, the EAC deferral expired and the 8­ Hour Ozone Control Area was designated as a non-attainment area onNovember 20, 2007. The RAQC, NFRMPO and the Divisionbeganholding publicly announced stakeholdermeetings in Fall 2007. Stakeholders attending meetings have included representatives from industry, consultants, EAC member agencies, government agencies, EPA, environmental groups, and the general public. Five stakeholder meetings were held which addressed proposed rule language for Stationary Sources. Input from all sectors has helpedto craft the proposed regulatory revisions included in this packet. How do proposed regulatory revisions affectthe public, regulated community, and other agencies? The proposedrevisions will protect pubic healthby reducing VOC emissions, an ozone precursor, which will reduce the potential for ozone formation and improve air quality. The regulated community will be required to: 1) place control and monitoring equipment on additional condensate tanks, 2) reduce emissions from pneumatic controllers by replacing most high-bleed controllers with low-bleed controllers (or by other means that will reduce emissions, such as using solarpowered devices), 3) report emissions at lower thresholds, 4) implement RACT inthe ozone NAA. An analysis ofthe costs associated with the additional controls is set forth in the Initial Economic Impact Analysis included withthis package. Other government agencies will benefit from the proposed rule revisions via improved air quality. How do the proposed rule revisions relate to federal and adjacent state requirements? The Division contacted adjacent states to betterunderstand their approaches towards condensate storage tanks and pneumatics. The proposed revisions will decrease ozone

4precursor formation which is beneficial to states downwind. Itis notedthatWyoming and Utah use BACT in their minor source permitting programs. Arizona: Arizona's permit de minimis is 40 tpy potential to emit (PTE). There is no BACT for minor sources, althoughthey are considering implementing it in future. Condensate Tank Batteries and Pneumatic Controllers: The oil and gas industry is limited to pipelines and fuels, therefore condensate tanks and pneumatic controllers are not specifically regulated at this time. Kansas: Kansas' permit de minimis is 40 tpy PTE. Condensate Tank Batteries: Some specific permits require controls however as a source category, tank batteries are not specifically regulated at this time. Pneumatic Controllers: Pneumatic controllers are not specifically regulated atthis time. Nebraska: Nebraska issues construction permits at40 TPY for VOC emissions. Condensate Tank Batteries and Pneumatic Controllers: The oil and gas industry is not specifically regulated atthis time for VOCs (more concerned about NOx). New Mexico: New Mexico's permit de minimis is 25 tpy PTE. There is no BACT for minor sources, although they are considering implementing it in future. Condensate Tank Batteries and Pneumatic Controllers: Condensate tanks and pneumatic controllers are not specifically regulated atthis time, although they are planning to implement changesthat resemble Colorado's Regulation 7. Utah: Utah's permitde minimis is 5tpy actual emissions. A BACT analysis is required for all sources above de minimis levels. Condensate Tank Batteries and Pneumatic Controllers: The oil and gas industry is not specifically regulated at this time; all rules are atthe Federal level. They are currently building an inventory and may regulate in future.



### 5

### Wyoming: BACT is required as discussed below. Condensate Tank Batteries: Minor source BACT programrequires controls on all condensate tank batteries within 60 days ofproduction statewide ifpredicted emissions are 20 tpy or greater. Controls may be removed after 1year ifemissions decline to less than 15 tpy. Minor source BACTprogram requires controls onall tank batteries upon first day ofproductioninthe Jonah/Pinedale Area Development (JPAD). Controls remain for the life ofthe tank battery. Pneumatic Controllers: Considering regulating pneumatic controllers by requiring one of three options: using low/no bleed devices, tie vent gas into gas line, or using compressed air ratherthannatural gas as actuating gas. Currently, BACTmustbe considered for statewide pneumatic pumps exceeding thresholds. In addition, all new and modified pneumatic pumps in the JPAD mustbe controlled. How will the regulatory revisions be implemented? The rule will be implemented through Regulations 3 and 7. The amended rules will be placed on the Commission website. Divisionpersonnel will be informed ofthese changes to ensure thatthe amended rules will be implemented. Are there time constraints? Ifadopted, the proposed amendments to Regulations 3 and 7will become effective in February 2009 such that VOC emissions reductions will occur for the next ozone season (beginning May 1,2009). However, industry and the Division will need some time in orderto implement these rules. Finally, adoption ofthe revisions must occur before December 31, 2008 in orderto meet SIP submittal deadlines. What ifthe Air Quality Control Commission does not adoptthe proposed Rule revisions? Ifthe Commission does not adopt any changes to Regulations 3 and 7 by December 31, 2008, Colorado may not achieve attainment by 2010, will miss the SIP submittal deadline, and may become subject to EPA's imposing ofaFederal Implementation Plan. Photochemical grid dispersion modeling indicates that without further emission controls, Colorado will attainthe 8-hour standard by 2010. The dispersion modeling reflects that Colorado would attainthe standard by a narrow margin

- within 0.001 ppm on a standard of0.084 ppm. Photochemical dispersion modeling analysis is the primary tool used to assess present and future air quality trends, and is required for EPAto approve the state attainment demonstration in the SIP. Dispersion modeling results have an inherent level ofuncertainty, as recognized in EPA guidance, and it is appropriate for a state to use othertools at its disposal, including further control measures, to address and mitigate any uncertainties that canbe present in dispersion modeling. It

### is appropriate for the state to use such tools to increase the confidence in and other wise ensure that the predicted modeling results are accurate and borne-out in future air quality monitoring demonstrating attainment withthe 8-hour standard.

6In addition, pursuant to EPA guidance, ifmodeling results indicate that the highest ozone levels will fall between 0.082 and 0.087 ppm, Colorado must conduct a "weight ofthe evidence" analysis and other supplemental analysis in order to corroboratethe modeling results. Colorado's model results are withinthis range, and thus the state has conducted this analysis. The analysis supports the conclusion that Colorado will attain the standard by 2010, although by a narrow margin. To increase the certainty ofthe model results and the Weight ofEvidence demonstration, the Commission concludesthat these additional control measures are necessary to carry out its mandate to adopt a SIP that contains those elements that are necessary to assure attainmentofthe ozoneNAAQS. Further, contrary to pastozone formation reductions in the DMAlNRF, modeling has indicatedthatNOxreductions, in addition to VOC emissionsreductions are beneficial in reducing ozone in the same area. The APCD's meteorological analysis supportsthis conclusion. Thus, the Commission has adopted ozone reduction strategiesthat include both VOC andNOxemissions reductions. Modeling and supplemental analyses indicate that measures designed to reduce these precursors will be most effective in reducing ozone. JUSTIFICATION FORDIFFERING FROM FEDERAL REQUIREMENTS The federal act does not expressly require the controls being proposed by the Division. Rather, federal law establishes the 8-hour ozone NAAQS and requires the State to develop a SIP adequate to attain the NAAQS. The Division proposes to adopt revisions to Regulations 3 and 7 to ensure attainment with the current 8-hour ozone NAAQS set at 0.08 ppm, and to achieve additional ozone reductions in light of both the new 8-hour ozone NAAQS set at 0.075 ppm and the Governor's July 27, 2007 directive to proactively and pragmatically reduce ozone levels.
RANGE OF REGULATORYALTERNATIVES The Commission could choose to adopt the Division proposal into the SIP, adopt as state­ only regulations, or not adoptthe proposal at all. Pursuantto C.R.S. §25-7-105(1)(a)(I), the Commission must adopt such measures as are necessary to ensure compliancewith the NAAQS. The Divisionbelieves these proposed revisions carry outthis mandate. NO-ACTION ANALYSIS Ifthe Commission does not adopt any changes to Regulations 3 and 7 by December 31, 2008, Colorado may not achieve attainment by 2010, will miss the SIP submittal deadline, and may become subjectto EPA's imposing ofa Federal Implementation Plan. PUBLIC MEETINGS The RAQC, NFRMPO, and the Division have held multiple meetings beginning in the Fall 2007 to develop ozone reduction strategies. The RAQC and the Division have held meetings specific to rule language development. Ifthe Commission grants the request for hearing ofthis proposal, the Commission will hold a Rulemaking Hearing onthe proposed rule. The Commissionwill establish a pre-hearingprocess to ensure an orderly hearing. Anyone may participate in the pre-hearing and hearing process by obtaining

7party status in accordance withthe Commission's Procedural Rules. Additional meetings may be held outside the pre-hearingprocess ifthere is sufficient interest from stakeholders. CONTACT INFORMATION: For more information please contact: Theresa Amoroso Regulatory Development Stationary Sources Program AirPollution Control Division 4300 Cherry CreekDrive South Denver, CO 80246-1530 Phone: (303) 692-3111 Fax: (303) 782-0278 E-mail: theresa.amoroso@state.co.us



### 8Initial Economic Impact Analysis for Proposed State Implementation PlanRevisions to the Air Quality Control Commission's RegulationNumber 3 and RegulationNumber 7 Regulation 3, Parts A, B, and C Regulation 7, Sections I-XVIII Per C.R.S. 25-7-110.5

September 18, 2008 I. REQUIREMENTS FORECONOMIC IMPACT ANALYSIS (EIA) Section 25-7-110.5 (4)(a), c.R.S. sets forth the requirements for initial and final Economic Impact Analysis, as stated below: "Before any permanentrule is proposedpursuant to this section, an initial economic impact analysis shall be conducted in compliance with this subsection (4) ofthe proposed rule or alternative proposed rules. Sucheconomic impact analysis shall be in writing, developed by the proponent, or the Division in cooperation with the proponent and made available to the public at the time any request for hearing on a proposedrule is heard by the commission. A final economic impact analysis shall be in writing and delivered to the technical secretary and to all parties ofrecord five working days prior to the prehearing conference. Ifno prehearing conference is scheduled, the economic impact analysis shall be submitted at leastten working days before the date ofthe rule-making hearing. The proponent ofan alternative proposal will provide, in conjunction with the Division, a final economic impact analysis five working days priorto the prehearing conference. The economic impact analyses shall be based upon reasonably available data. Exceptwhere data is notreasonably available, or as otherwise provided in this section, the failure to provide an economic impact analysis ofany noticed proposed rule or any alternative proposed rule will preclude suchproposedrule or alternative proposedrule from being considered by the Commission. Nothing in this section shall be construed to restrict the Commission's authority to consideralternative proposals and alternative economic impact analyses thathave notbeen submitted priorto the prehearing conference for good cause and so long as parties have adequate time to reviewthem." The Air Pollution Control Division (Division) has selected C.R.S. § 25-7-110.5(4)(c)(III), which calls for an EIAthat: (A)Identifies the industrial and business sectors that will be impacted by the proposal; and (B) Quantifies the direct costto the primary affected business or industrial sector; and (C)Incorporates an estimateofthe economic impact ofthe proposal on the supporting business and industrial sectors associated with the primary affected business or industry sectors. An EIA need only be based upon reasonably available data (§25-7-110.5(4)(a), C.R.S.).



### 1II. DISCUSSION Analysis Background This Economic ImpactAnalysis (EIA) considers impacts from implementing proposed regulations that are aimed at reducing ground level ozone within the nonattainment area (NAA) by reducing emissions ofozone precursors, volatile organic compound (VOC) from the following sources:

• Oil and gas industry condensatetanks in the ozone non-attainment area, • Oil and gas industry pneumatic controllers inthe ozone non-attainment area, • Multiple industries through expansion ofRegulation 7 Reasonably Available Control Technology (RACT) applicability inthe ozone non-attainment area, and • Multiple industries through revising Regulation 3 Air Pollution EmissionNotice (APEN) reporting and permittingexemptions state-wide (this strategy alone will not reduce VOC emissions; it is intended to provide information and increase equity). These proposedrevisions are necessary to ensure attainment with the current 8-Hour Ozone National Ambient Air Quality Standard (NAAQS) set at 0.08 parts permillion (ppm), and to otherwise achieve ozone reductions in light ofboth the new 8-Hour Ozone NAAQS set at 0.075 ppm and the Governor's July 27, 2007 directive to proactively and pragmatically reduce ozone levels. Proposed Rules These proposedrevisions accomplish five objectives: A) reduce volatile organic compound (VOC) emissions from oil and gas operations in the ozone non-attainment area, B) revise the control requirements for condensate tanks by transitioning from a system-wide to an emissions threshold control strategy in the ozone non-attainment area, C) expand VOC RACTrequirements suchthat all ozone non-attainment areas are subjectto Regulation 7's RACT requirements, D) clarify howthe RACT requirements in Regulations 3 and 7 interact in the ozone non-attainment area, E) improve the Division's inventory ofspecific source category emissions state-wide; and F) make typographical, grammatical and formatting changes for greater clarity andreadability. Condensate TankProposed Rules in the OzoneNon-attainment Area Proposed rules further reduce VOC emissions by: 1) requiring control device and monitoring equipment installation and operation during the first 90 days ofoperation beginning February 1, 2009; 2) redefining modification activities that trigger additional control and monitoring equipment installation and operationbeginning February 1, 2009; 3) lowering the applicability thresholds for new and modified tanks from five down to two tons peryear ofVOCsbeginning February 1,2009 and for existing tanks from 20 down to 10 tons peryear ofVOCs; and 4) increasing control requirement by initially increasing system-wide control requirements in May 1, 2009, ultimately transitioning to a emissions threshold control strategy beginning in May 1, 2010. Affectedtanks are required to control emissions by 95% and to monitor associated air pollution control equipmentto ensure compliance.

2Tanks serving newly drilled, recompleted or stimulated wells be required to employ air pollution control equipment during the first 90 days ofproduction. Air pollution control equipment can include combustion devices, vaporrecovery units, orDivision approved alternative controls or pollution prevention activities thatmeetthe control efficiency requirement. Ifafter the first 90 calendar days, the data shows that annual emissions from the tank will not exceedthe control requirementthreshold, the control may be removed. Enhanced monitoring provisions are proposed for condensate tanks as an indicatorofcompliance to ensure actual emissions reductions occur. In many cases, condensate tanks are remotely located and un-manned. For combustion control devices (flares), auto-igniters and electronic surveillance systems are requiredto identify whenthe pilot is not lit and attempt to relight it, document the duration oftime when the pilot is not lit, and notify an operatorthat repairs are necessary to ensure proper control operation and ensure control operation. Proposed recordkeeping and reporting requirements are minimized to offset the added control assurance gained through enhanced monitoring. This revision reduces the frequency and reporting ofemissions estimation calculations, from a weekly to a rolling-12 month basis and from annual company-wide reporting to reporting upon request ofthe Division (normally during routine inspections or via APEN updates for significant increases in annual emissions). Pneumatic Controller Proposed Rules inthe Ozone Non-attainment Area Proposedrules require new pneumatic controllers be at least low-bleed devices beginning February 1, 2009, and existing high-bleed pneumatic devices be retrofit orreplaced with lowbleed devices, or devices with equivalent or lower VOC emissions, by May 1,2009. An exception will allowhigh-bleed devices to be used ifthe Division determines that a safety or process reason makes it technically infeasible to use a low-bleed device. Operators will be requiredto inspect high-bleed devices on a monthly basis and perform maintenance as needed. Operators will be required to keep logs ofthe number ofdevices, device type, and inspection and maintenance that is performed. Operators will be required to tag the devices, which will help enable the Division to track compliance. Regulation 7 Expansion ofRACTProposed Rules in the Ozone Non-attainment Area Proposed rules will require that Regulation 7 expand the applicability ofReasonably Available Control Technology (RACT) requirements to existing, new, and modified sources outside ofthe historic I-hour Ozone Non-attainment or Attainment/Maintenance Area, beginning February 1, 2009. This proposedregulation change is based on equity

- sources inthe I-hour Ozone Nonattainment orAttainmentlMaintenance Area already comply with Regulation 7. The Division believes all ozone non-attainment areas (existing and future designations) should comply with Regulation 7. Regulation 3Exemptions Proposed Rules State-wide Proposed rules will revise APEN reporting exemptions for specific source categories, beginning February 1,2009. This regulation change is based on equity. Most sources ofVOC emitting one or more tonperyear file an APEN and obtain a permit ifthey emit two or more tons peryear in the ozone non-attainment area (or two or more tonper yearfile an APEN and obtain a permit
3

### ifthey emit five or more tons per year in all other areas). This proposal requires source categories currently exempt from these thresholds to obtainAPENs and permits at those same thresholds as other sources inthe respective areas. Edits to Regulation 7 Proposed Rules Proposedrules will be revised to correcttypographical, grammatical and formatting changes, as necessary, beginning February 1, 2009. Data Used in EIA 

### To perform the EIA, the following information must be obtained to calculate industry's costs to implement the proposed regulation: 1) number ofcontrol and monitoring devices required, 2) associated costs, and 3) emission reductions thatcanbe achieved. For those proposals specific to Regulation 7 expansion ofRACT, Regulation 3 Exemptions and edits to Regulation 7, detailed data is not reasonably available. There are innumerable types of facilities that would be subject to these Regulation 3 and 7 proposed rules. For example, any emission source in an ozone non-attainment area that emits VOC emissions would be subject to the expansion of RACT, and since not previously subject to RACT, these sources may have never been required to report emissions to the Division. Such facilities include, without limitation, oil and gas facilities, food processing and packaging facilities, refineries, dry cleaners, printers and other surface coating operations. Within each ofthese categories, there are many different facilities of varying sizes and configurations, which compounds the difficulty in estimating costs ofVOC emissions control. While potential costs associated with undertaking an analysis of control technology may be capable of general estimation and quantification, the potential costs associated with installing control technologies do not lend themselves to the same analysis. Such information is not reasonably available, in that it is so fact-specific as to preclude meaningful, generalized analysis. Such costs would be dependent upon numerous site-specific factors, including the type of facility, the amounts and types and constituents emitted by the facility, the concentrations ofodors, the configuration ofthe facility (for example, whether there is space available to install certain types ofequipment). Thus, the Division has an inaccurate inventory of these sources and associated emissions at this time and limits any cost analysis which may be performed. This is also true for sources affected by Regulation 3 reporting and permitting exemption changes. Clarifying edits to Regulation 7, edits are minimal and impacts are believed to be negligible Thus the Division focused efforts on this economic impact analysis on impacts to the oil and gas industry in controlling emissions from condensate tanks and pneumatic controllers. Condensate TankEIA Data The number ofunits (tanks ortank batteries) that will need to install control devices and conduct monitoring under the proposed rule and the controlled and uncontrolled emissions from large units were based on the Division's emissions inventory (data reported to the Divisionby industry via APENs) for the 2007 inventory year. The number ofsmall tanks or tank batteries (those having actual uncontrolled emissions ofequal to or more than 10 tpy uncontrolled VOC emissions) that will need to install control devices
4under the proposed rule was based on the Division's emissions inventory for the 2007 inventory year. Because the current reporting threshold is higher than five tons peryear, and therefore the Division's emissions inventory is limited, the controlled and uncontrolled emissions from small units were based on data gathered withinthe ozone non-attainment area by Independent PetroleumAssociation ofMountain States (lPAMS). The cost ofcontrolling emissions was based ondata collected from the oil and gas industry. Pneumatic Controller EIA Data The number ofhigh-bleed pneumatic controllers in place and associated emission reductions that could be obtained by retrofitting orreplacing some ofthem were estimated based on data gathered within the ozone non-attainment area by IPAMS. The percentage ofhigh-bleed pneumatic controllers that will be replaced orretrofit is based on data gatheredby the Division from industry. Controller capital, installation, andmaintenance cost data was obtained from vendors. Because this strategy increases the amount ofnatural gas that companies can sell, the strategy pays for itself. The U.S. natural gas wellhead price used in this analysis, $10.82 per thousand standard cubic foot, was currentas ofJune 2008. Regulation 7 Expansion ofRACT EIA Data Cost data is not readily available for this proposed regulation change. Industry has not indicated that this proposed regulation change will have a significant impact. Regulation 3 Exemptions EIA Data Cost data is not readily available for this proposed regulation change. The cost offiling an APEN is $152.90. Annual fees andpermit fees vary by source type. Edits to Regulation 7 EIA Data Costdata is not available to this proposed regulation change. Industry has not indicated that this proposed regulation change will have a significant impact. Impact to Public The public will be indirectly affected by the proposed rule. Reductions in VOC emissions will reduce the incidence ofozone induced human health impacts causedby pulmonary, cardiovascular, respiratory, and nervous system disease. Ozone damages crops, forests, and othernatural plantlife, so these will benefit ifVOC emissions are reduced. Reducing emissions from pneumatic controllers will also reduce methane, which is a greenhouse gas and contributes to climate change. Itis not within the scope ofthis analysis to determine ifthe public will face increased costs associated with the proposed regulation. The associated benefit ofimproved public and environmental health from this proposal is difficultto assess. Impact to Administration



### 5Implementing the proposedrule has the potential to significantly increase the number of regulated sources, and has reporting, permitting, and/orcompliance assurance impacts to the Division. Itis beyond the scope ofthis analysis to determine costs to the Division associated with rule implementation. III. ECONOMIC IMPACT ANALYSIS Various industrial and business sectors will be impactedby this proposal: • Oil and gas (controls for condensate tanks, reducing use ofhigh-bleed pneumatic controllers), and • Other stationary sources ofVOC. Supportingbusiness and industrial sectors associated withthe primary affected business and industry sectors will benefit by selling equipmentto the primary affected business and industrial sectors. For example, as aresult ofthe proposedregulation, more flares will be sold and, inthe shortterm, more low-bleedpneumatic controllers will be sold to replace the high-bleed controllers currently inthe field. Calculating supporting economic impacts is beyond the scope ofthis document. As directed by CRS 25-7-110.5, this EIA does not include an analysis ofany nonmarket costs or external costs asserted to occur notwithstanding compliance by a source with applicable environmental regulations. Directcosts to the primary affected business and industrial sectors are shown inthe remainder of this section. Condensate Tank EIA for 8-hour Ozone Non-Attainment Area (NAA)
Table 1: 8-hour Ozone NAA Retrofit ofCondensate Tanks with Flare Control Device and Surveillance System Tanks CostAnalysis:

Flares @ 

### 95% CE >10and<20tpy uncontrolled Controlled VOC Emissions (tpd) (tpy) 27.2 9,936 Annualized Cost Per Unit $8,419 Number ofUnits Controlled 773 CostPerTon $655

6Table 2: Condensate Tank Annualized Costs for Flare Control Device and Surveillance System 

### Condensate Tank: Flare ControlDevice 

### wi SurveillanceSvstem

Item Capital Costs (one time) Non Recurring (one time) O&M (recurring) Annualized Total Cost (15yrs) Flare $16,540


### - 

## -

$8,419 Freight & Design 

### - $1,500 

### - Flare Installation 

### - $6,354 

### - Auto Igniter $1,500


### - - Surveillance System $3,600


### - 

## - Pilot Fuel 

### - - $1,897 Maintenance 

## - - $2,000 Data Management 

### - - $1,000

Subtotal Costs $21,640 $7,854 $4,897 Annualized Costs $2,999 $524 $4,897 Table 3: 8-hour OzoneNAA Retrofit ofCondensate Tanks with Vapor Recovery Unit (VRU) Control Device 

### Tanks CostAnalysis: VRU (ii) 95% 

### Control >10and <20

### tpy uncontrolled Controlled VOC Emissions (tpd) (tpy) 27.2 9,936 Annualized Cost Per Unit $19,078 Number ofUnits Controlled 773 Cost Per Ton $1,484 Table 4: Condensate Tank Annualized Costs for Vapor Recovery Unit Control Device

### Co~densate Tank: VaporRecovery Unit (VRU CostAnalysis

Item Capital Costs (one time) Non Recurring (one time) O&M 

### (recurring) FuelSales (recurring) Annualized Total Cost

(15yrs) VRU $78,000

- 

### - -

$19,078 Freight & Design 

### - $1,500 

### - 

## - VRU Installation 

### - $10,154 

### - - Maintenance

- 

### - $8,553


## - RecoveredNatural Gas 

### - - - ($1,063) Subtotal Costs $78,000 $11,654 $8,553 ($1,063) Annualized Costs $10,810 $777 $8,553 ($1,063)

7Pneumatic ControllerEIA for 8-hour OzoneNAA Pneumatic Controller: ConvertingtoLow-BleedControllersandPeiforming EnhancedMaintenanceonRemainingHigh-BleedCostAnalysis Number ofHigh-Bleed Controllers 5,524 Number ofConverted Controllers' 5,248 NumberofRemaining High-Bleed Controllers 276 Controlled Emissions (tons per day/year) 23.3 /8,496 Annualized Costper Controller ($1,505) CostperTon ($747) 1 Number ofhigh-bleed controllers that can be retrofit orreplaced with low-bleed controllers is calculated by assuming a 95% conversion rate

8

### State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i) Interstate Transport Regarding 8-Hour Ozone

DRAFT November 5, 2008 Colorado Department of Public Health and Environment Air Pollution Control Division 4300 Cherry Creek Drive South Denver, Colorado 80246Colorado Department ofPublic Health and Environment/ Air Pollution Control Division

i DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division


# Table of Contents 1. OZONE-SPECIFIC PROVISIONS TOMEET THE REQUIREMENTS OF CAA llO(A)(2)(D)(I)­ INTERSTATE TRANSPORT 1 1.1. INTRODUCTION I 1.2. COLORADO OZONE MONITORING NETWORK 2 1.3. OZONE MONITORING NETWORK IN NEARBY STATES 7 104. OZONE TRANSPORT CONCLUSIONS FROM THE DMAINFR PHOTOCHEMICAL MODELING 10 1.4.1. Emission Inventories and2006and2010 Base Case II 1.4.2. Discussion of 2010 Base Case CAMx Modeling Resufts 15 1.5. DENVERMETRO AREAINORTH FRONT RANGE OZONE NONATTAINMENT AREA CONTRIBUT10N TO DOWNWIND LOCATIONS 18 1.6. SECTION II0(A)2

- OZONE TRANSPORT CONCLUSIONS 20 2. REFERENCES 22 

# List ofTables Table 1: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 4 Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30,2008) 5 Table 3: Monitored 8-Hour DesignValue Using the 3-Year (2006-2008) Average ofthe Fourth Maximum Ozone Concentration 6 Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming (see Table 5 for additional data) 7 Table 5. 2005-2007 3-YearFourth Highest Average Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming (see Table 4 for additional data) 8 Table 6. Base Case Inventories for 8-Hour Ozone DMA/NFRNAA Photochemical Modeling 14


# List of Figures Figure 1. LocationofFront Range Ozone Monitors 2 Figure 2. Location ofStatewide Ozone Monitors 3 Figure 3: 8-Hour OzoneNonattainmentAreas 9 Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE emissions modeling 10 Figure 5. Projected 2010 8-hourozone Design Values (DVF) 15 Figure 6. Rocky FlatsNorth source apportionment for 29 July including boundary conditions 16 Figure 7: Spatial extent ofthe 8-hour ozone concentrations that occurred between lOam and 6pm local time onJune 27, 2002 through July 1, 2002 19

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. Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

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- State ofColorado Implementation Plan to Meet the Requirements of CleanAirAct Section 110 (a)(2)(D)(i) -Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division



## 1. Ozone-Specific Provisions to Meet the Requirements of CAA 11O(a)(2)(D)(i) - Interstate Transport 1.1. Introduction The purpose ofthis document is to provide a technical basisfor the State ofColorado's plan to meet the requirements ofthe Clean Air Act Section 110 (a)(2)(D)(i) Interstate Transport requirements regarding the 0.08 parts per million (ppm) 8-Hour Ozone National Ambient Air Quality Standard (NAAQS). This addresses the applicable components of 110(a)(2)(D)(i) demonstrating adequate provisions to preventemissions from Colorado from interfering with attainment or maintenance ofthe federal ozoneNAAQS in any other state. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour Ozone NAAQS. This document replaces the section titled "Ozone-Specific Provisions" in the document "State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour Ozone and PM25 NAAQS." Currently, the Denver area is the only areain U.S. Environmental Protection Agency (EPA) RegionVIII that is designated as nonattainment for the 8-hour ozone NAAQS of 0.08 ppm. In this report, relevant information from the Denver Metropolitan Area and North Front Range (DMAlNFR) 8-hour Ozone State Implementation Plan (SIP) process, the Denver Early Action Compact (EAC) process, ambient ozone data for Colorado, ambient ozone data for nearby states from the EPA Air Quality System (AQS) database, and other information is used to demonstrate that Colorado does not contribute significantly to nonattainment in, or interfere with maintenance by, any other state withrespect to the 0.08 ppm ozoneNAAQS.

1 DRAFT

- State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section I10 (a)(2)(D)(i)

- InterstateTransport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment 1Air Pollution Control Division


### 1.2. Colorado Ozone Monitoring Network The 2007/2008 ozone ambient air monitoring network in the Denver area and along the northern Front Range consists of 13 stations operated by the Colorado Air Pollution Control Division (APCD) and one station operated by the National Park Service (NPS) in Rocky MountainNational Park. There have been other stations that have operated in the past. The geographical distribution ofthe Front Range monitors is presented in Figure 1. As shown in Figure 1, the ozone monitors are primarily located in urbanized areas along the Front Range corridor. The monitors are located in areas wherethe highest ozone concentrations have been monitored historically and where elevated ozone is expected to occur. High ozone concentrations along the Front Range occur near the areas with high emissions density and dense population. Inaddition, elevated ozone is observed along elevated terrainto the west ofthe DMA/NFRNonattainmentArea. All ofthese monitors are designated by the U.S. Environmental ProtectionAgency as "equivalent" analyzers and follow all quality assurance requirements as specified in40 CFRPart 58, Appendix A.

Ramah .osimla·
,­ - /'9--<:: :: Figure I. Location ofFront Range Ozone Monitors

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- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(0)(i)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment I Air Pollution Control Division

Figure 2 shows other ozone monitoring sitesthat exist in Colorado for 2008. These are operated by either Colorado, the Southern Ute Tribe, or various Federal agencies. All of these sites use monitors that are designated as "equivalent" analyzers by the U.S. Environmental Protection Agency. As shown, most ofthe sites are in the southwest comer ofColorado, either within ornear the SanJuan oil and gas development area.

"N<l"1.1t,.,"",w**T'~lh.llllK_, ~1\rI101".**  ("

,**!l.16Y-'·~ ;ipf't<lq1'''~''~"**  L'!lltll'" 'M Pn1:d'l4't\j.1'So.r ..... h;'QM'l>e'l'l**~.. "~~~.'v**  ••.**::~0'1"~~~.:~ ~-;~(;~**  0;;**-~**
Figure 2. Location ofStatewide Ozone Monitors Table I, Table 2, and Table 3presentthe monitoring data for the DMAlNFRNAA monitoring sites (including the NPS Rocky MountainNational Park monitoring site) as well as for other sites in Colorado. In Table 3, the fourth maximum 8-hour ozone concentrations along with the 3-year average ofthe fourth maximum concentrations at each site are presented. As shown in bothTable I and Table 3, the Denver area is currently meeting the 8-hour and former I-hour ozoneNAAQS for all sites, exceptfor the 8-Hour NAAQS at Rocky FlatsNorth with a design value of0.86 ppm.

3 DRAFT

- State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division


### Table I: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008)
AQS Number Site Name 1stMax I-Hour (ppm) Date 1stMax I-Hour 2nd Max I-Hour (ppm) Date 2nd Max

I-Hour 3rd Max I-Hour (ppm) Date 3rd Max I-Hour 4th Max I-Hour (ppm) Date 4th Max I-Hour 08-001-3001 Welby 0.100 08/29 0.095 08/05 0.092 07/10 0.089 06/20 08-005-0002 

### * Highland 0.065 04/04 0.064 04/08 0.064 04/18 0.062 04/19 08-013-0011 S. Boulder Creek 0.089 07/10 0.089 07/25 0.086 07/16 0.085 05/31 08-031-0014 Carriage 0.094 08/05 0.090 08/29 0.089 07/10 0.085 06/20 08-031-0025 

### ** Denver

- Animal Shelter 0.100 07/10 0.098 08/05 0.087 06/20 0.087 08/24 08-035-0004 Chatfield State Park 0.101 07/10 0.098 06/20 0.095 08/29 0.092 08/24 08-041-00 13 Colo. Spgs.

- Academy 0.085 OS/24 0.083 07/10 0.082 08/06 0.080 07/18 08-041-0016 Manitou Springs 0.087 OS/24 0.085 08/06 0.083 07/10 0.083 07/11 08-045-0012 

### ** Rifle

- Health 0.081 07/09 0.080 07/10 0.075 08/19 0.074 07/11 08-059-0002 Arvada 0.093 08/05 0.093 08/29 0.092 07/10 0.088 07/25 08-059-0005 Welch 0.102 07/10 0.090 06/20 0.088 08/05 0.088 08/29 08-059-0006 Rocky Flats - N 0.088 07110 0.088 07/18 0.088 08/29 0.087 07/02 08-059-0011 NREL 0.097 08/29 0.093 07/10 0.092 08/05 0.092 08/24 08-067-7001 

### *** So. Ute

- Ignacio 0.076 06/04 0.075 05/31 0.073 05/03 0.072 05/3 08-067-7003 

### *** So. Ute

- Bondad 0.080 06/04 0.078 05/31 0.077 OS/27 0.071 04/21 08-067

-???? USFS

- Shamrock 0.081 06/04 0.079 06/10 0.077 02/29 0.077 05/30 08-069-0007 Rocky Mountain Nat'l Park 0.092 07/09 0.090 07/31 0.090 08/28 0.085 OS/22 08-069-00I I Ft. Collins

- West 0.093 08/19 0.092 07/09 0.092 07/18 0,088 07/24 08-069-1004 Ft. Collins

- CSU 0.082 08/19 0.080 07/09 0.079 08/30 0.078 07/24 08-077-0020 

### ** Palisade

- Water 0.081 07/09 0.079 07/10 0.075 07/08 0.074 07/05 08-083-0006 

### ** Cortez 0.078 07/23 0.074 07/13 0.072 08/05 0.071 07/25 08-083-0101 Mesa Verde Nat'l Park 0.075 05/01 0.075 06/04 0.074 05/31 0.072 04/30 08-123-0009 Greeley

- Weld Tower 0.094 08/20 0.092 07/24 0.089 08/01 0.087 08/04
NOTES: 

### * Highland site shut down on 4/21/08 for approx. 6-months. 

### ** Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

### *** Southern Ute sites data only thru 6/30/08.

4 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division
Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008)
AQS Number Site Name lst Max 8-Hour (ppm) Date lstMax 8-Hour 2nd Max 8-Hour (ppm) Date 2nd Max 8-Hour 3rd Max 8-Hour (ppm) Date 3rdMax 8-Hour 4th Max 8-Hour (ppm) Date 4th Max 8-Hour 08-001-3001 Welby 0.085 07/10 0.083 08/29 0.077 07/18 0.076 06/20 08-005-0002 

### *Highland 0.062 04/04 0.060 04/08 0.060 04118 0.059 04/05 08-013-0011 S. Boulder Creek 0.080 07110 0.076 05/31 0.076 07/09 0.076 07/18 08-031-0014 Carriage 0.081 07/10 0.075 08/29 0.073 06/20 0.072 07/26 08-031-0025 

### ** Denver

- Animal Shelter 0.086 07/10 0.072 08/29 0.071 07/13 0.070 07/26 08-035-0004 Chatfield State Park 0.090 07/10 0.082 06/30 0.080 06/20 0.080 06/27 08-041 -001 3 Colo. Spgs.

- Academy 0.078 OS/24 0.077 07/10 0.073 08/06 0.070 07/18 08-041 -0016 Manitou Springs 0.080 OS/24 0.076 07/10 0.074 07/11 0.072 07/31 08-045-0012 

### ** Rifle

- Health 0.076 07/09 0.076 07/10 0.069 08/19 0.066 07/13 08-059-0002 Arvada 0.081 08/29 0.080 07/10 0.077 06/20 0.074 08/05 08-059-0005 Welch 0.095 07/10 0.079 06/20 0.077 07/18 0.073 08/19 08-059-0006 Rocky Flats - N 0.083 07/10 0.080 07/18 0.079 05/31 0.079 08/29 08-059-0011 NREL 0.085 07/10 0.085 08/29 0.077 06/20 0.076 06/02 08-067-7001 

### *** So. UteIgnacio 0.069 06/04 0.067 06/10 0.066 05/10 0.066 06/13
08-067-7003 

### *** So. UteBondad 0.073 06/04 0.067 OS/27 0.067 05/31 0.067 06/05 08-067

-???? USFS

- Shamrock 0.074 06/04 0.073 06/10 0.071 06/13 0.069 05/30 08-069-0007 Rocky Mountain Nat'l Park 0.081 07/09 0.077 OS/25 0.077 07/31 0.076 05/31 08-069-00II Ft. Collins

- West 0.081 07/18 0.079 07/09 0.078 OS/25 0.076 07/24 08-069-1004 Ft. Collins

- CSU 0.070 OS/25 0.070 07/09 0.068 07/18 0.066 05/31 08-077-0020 

### ** Palisade

- Water 0.077 07/09 0.075 07110 0.070 05/31 0.070 07/29 08-083-0006 

### ** Cortez 0.067 08/02 0.066 07/23 0.065 08/07 0.064 08/05 08-083-0101 Mesa Verde Nat'l Park 0.071 06/04 0.070 04/30 0.069 04/21 0.069 06110 08-123-0009 Greeley

- Weld Tower 0.077 07/24 0.076 08/20 0.075 07/26 0.073 08/01 NOTES: 

### * Highland site shut down on 4/21/08 for approx. 6-months. 

### ** Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

### *** Southern Ute sites dataonly thru 6/30/08.

5 DRAFT

- State ofColorado Implementation Plan to Meetthe Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

Table 3: Monitored 8-Hour Design Value Using the 3-Year (2006-2008) Average ofthe Fourth Maximum Ozone Concentration

SiteName AQS# 2006 

## 7 Maximum

8-Hour Average Value (ppm) 2007 

## 7 Maximum

8-Hour Average Value (ppm) 2008 

## 7 Maximum

8-Hour Average Value (ppm) Design Value (2006

- 2008) 3-Year Average 4th Maximum Value (ppm) Welby 08-001-3001 0.069 0.070 0.076 0.071 • Highland 08-005-0002 0.081 0.075 0.059 0.071 S. Boulder Creek 08-013-0011 0.082 0.085 0.076 0.081 Carriage 08-031-0014 0.072 0.076 0.072 0.073 •• Denver

- Animal Shelter 08-031-0025


### --­ --­ 0.070


### --- Chatfield State Park 08-035-0004 0.086 0.082 0.080 0.082 USAF Academy 08-041-0013 0.072 0.072 0.070 0.071 Manitou Springs 08-041-0016 0.076 0.072 0.072 0.073 •• Rifle

- Health 08-045-0012


### --­ --­ 0.066


### --­ Arvada 08-059-0002 0.082 0.079 0.074 0.078 Welch 08-059-0005 0.081 0.080 0.073 0.078 Rocky Flats

- North 08-059-0006 0.090 0.090 0.079 0.086 NREL 08-059-0011 0.083 0.085 0.076 0.081 ••• So. Ute

- Ignacio 08-067-7001


### --­ --­ 0.066 

## --­ ••• So. Ute

- Bondad 08-067-7003 0.063 0.071 0.067 0.067 USFS

- Shamrock 08-067-1717 0.074 0.069 0.069 0.070 Rocky Mountain Nat'l Park 08-069-0007 0.076 0.078 0.076 0.076 Fort Collins

- West 08-069-00II 0.087 0.085 0.076 0.082 Fort Collins

- CSU 08-069-1004 0.078 0.069 0.066 0.071 •• Palisade

- Water 08-077-0020 

## --­ --­ 0.070


### --­ •• Cortez 08-083-0006 

## --­ --­ 0.064


### --­ Mesa Verde Nat'l Park 08-083-0101 0.074 0.070 0.069 0.071 Greeley

- Weld Tower 08-123-0009 0.082 0.074 0.073 0.076 NOTES: • Highland site shut down on 4/21/08 for approx. 6-months

. •• Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Water commenced on 5/30/08 and Cortez commenced on 6/17/08

. ••• Southern Ute sites data only thru 6/30/08. Ignacio data invalid for 0112005 to 08/2007.

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- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment / Air Pollution Control Division 

## 1.3. Ozone Monitoring Network in Nearby States Table 4 and Table 5 present 8-hour ozone monitoring data from the surrounding states of Nebraska, Kansas, NewMexico, Wyoming, and Utah. Table 4 and Table 5 showthat none ofthe monitors in surrounding states exceed the 8-hour ozone standard. Therefore, to the extent that the network is representative ofall areas, it can be concludedthatthe DMAfNFR sources do not significantly contribute to the 8-hour ozone standard violations at these down wind locations or even further downwind.
Table 4: 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming (see Table 5 for additional data)

Site ID State County EPA Re2ion 2005 8-hr Ozone 4th Max

(ppm) 2006 8-hr Ozone 4th Max

(ppm) 2007 8-hr Ozone

4th Max

(ppm) 3-yr Avg. of 4th Max

(ppm) 20-045-0004 KS Douglas 7 0.073 0.081 End 2007 N/A 20-091-0010 KS Johnson 7 0.081 0.076 0.071 0.076 20-103-0003 KS Leavenworth 7 0.077 0.074 0.080 0.077 20-107-0002 KS Linn 7 0.075 0.079 0.070 0.074 20-173-000I KS Sedgwick 7 0.065 0.065 0.059 0.063 20-173-0010 KS Sedgwick 7 0.074 0.073 0.060 0.069 20-191-0002 KS Sumner 7 0.078 0.080 0.070 0.076 20-195-000I KS Trego 7 0.071 0.076 0.068 0.071 20-209-0021 KS Wyandotte 7 0.079 0.081 0.073 0.077 31-055-0028 NE Douglas 7 0.069 0.072 0.066 0.069 31-055-0032 NE Douglas 7 0.067 0.066 0.056 0.063 31-055-0035 NE Douglas 7 0.070 0.067 0.061 0.066 31-109-0016 NE Lancaster 7 0.056 0.056 0.054 0.055 35-001-0019 NM Bernalillo 6 0.073 0.073 0.070 0.072 35-001-0023 NM Bernalillo 6 0.072 0.073 0.069 0.071 35-001-0024 NM Bernalillo 6 0.074 0.074 0.068 0.072 35-001-0027 NM Bernalillo 6 0.073 0.072 0.071 0.072 35-001-0029 NM Bernalillo 6 0.071 0.070 0.067 0.069 35-001-1012 NM Bernalillo 6 0.077 0.047 0.074 0.066 35-001-1013 NM Bernalillo 6 0.077 0.071 0.071 0.073 35-001-1014 NM Bernalillo 6 0.072 0.072 0.064 0.069 35-013-0008 NM Dona Ana 6 0.070 0.072 0.068 0.070 35-013-0017 NM Dona Ana 6 0.070 0.073 0.070 0.071 35-013-0020 NM Dona Ana 6 0.072 0.072 0.068 0.070 35-013-0021 NM Dona Ana 6 0.076 0.080 0.076 0.077 35-013-0022 NM Dona Ana 6 0.070 0.073 0.073 0.072 35-013-0023 NM Dona Ana 6 0.066 0.070 0.062 0.066

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- State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division
Table 5. 2005-2007 3-YearFourth Highest Average Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming (see Table 4 for additional data)

Site ID State County EPA**Re~ion** 2005 8-hr Ozone 4th Max

(ppm) 2006 8-hr Ozone 4th Max

(ppm) 2007 8-hrOzone

4th Max

(ppm) 3-yr Avg. of 4th Max

(ppm) 35-015-1005 NM Eddy 6 0.067 0.076 0.066 0.069 35-017-1003 NM Grant 6 0.071 0.067 0.062 0.066 35-025-0008 NM Lea 6 0.074 0.075 0.064 0.071 35-029-0003 NM Luna 6 Start 2006 0.053 0.062 N/A 35-043-1001 NM Sandoval 6 0.069 0.064 0.063 0.065 35-043-1003 NM Sandoval 6 0.075 0.074 0.071 0.073 35-043-9004 NM Sandoval 6 0.076 0.072 0.067 0.071 35-045-0009 NM San Juan 6 0.075 0.063 0.069 0.069 35-045-0018 NM San Juan 6 Start 2006 0.079 0.079 N/A 35-045-1005 NM San Juan 6 0.072 0.071 0.073 0.072 49-003-0003 UT Box Elder 8 0.079 0.078 0.077 0.078 49-003-7001 UT Box Elder 8 0.075 0.076 0.078 0.076 49-005-0004 UT Cache 8 0.069 0.073 0.074 0.072 49-011-0004 UT Davis 8 0.092 0.082 0.082 0.085 49-035-0003 UT Salt Lake 8 0.083 0.084 0.082 0.083 49-035-2004 UT Salt Lake 8 0.086 0.082 0.082 0.083 49-035-3006 UT Salt Lake 8 0.082 0.082 0.079 0.081 49-035-3007 UT Salt Lake 8 0.085 0.080 0.080 0.081 49-035-3008 UT Salt Lake 8 0.080 0.082 0.079 0.080 49-037-0101 UT San Juan 8 0.069 0.070 0.072 0.070 49-045-0003 UT Tooele 8 0.080 0.079 0.076 0.078 49-049-0002 UT Utah 8 0.078 0.074 0.075 0.075 49-049-5008 UT Utah 8 0.080 0.077 0.078 0.078 49-049-5010 UT Utah 8 0.080 0.079 0.077 0.078 49-053-0130 UT Washington 8 0.091 0.072 0.071 0.078 49-057-0007 UT Weber 8 0.081 0.083 0.080 0.081 49-057-1003 UT Weber 8 0.084 0.083 0.082 0.083 56-005-0123 WY Campbell 8 0.063 0.072 0.072 0.069 56-005-0456 WY Campbell 8 0.063 0.065 0.072 0.066 56-035-0098 WY Sublette 8 0.075 0.069 0.068 0.070 56-035-0099 WY Sublette 8 0.079 0.072 0.067 0.072 56-035-0100 WY Sublette 8 0.066 0.074 0.066 0.068 56-037-0200 WY Sweetwater 8 Start 2006 0.067 0.064 N/A 56-039-1011 WY Teton 8 0.060 0.069 0.065 0.064 Figure 3 presents a map ofall the U.S. nonattainment areas. Since the surrounding states ofKansas, Nebraska, Wyoming, Utah, and NewMexico do not have violations the 8-hour NAAQS for ozone, it canbe reasonably concluded that Colorado sources do not significantly affect the ozone nonattainment areas evenfurther downwind such as Dallas8 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment IAir Pollution Control Division
Forth Worth and 81. Louis nonattainment areas. In addition, it is unlikely that Colorado would significantly affect nonattainment areas that are typically "upwind" such as Las Vegas and Phoenix. However, it is recognized that, under the types ofsynoptic scale meteorological regimes that occur during some regional ozone episodes, simple terms like "upwind" and "downwind" may not be applicable. Thus, photochemical modeling is neededto study the distribution ofozone under a variety ofmeteorological regimes.

Nonattainment and Maintenance Areas in the U. S. 8-hour Ozone Standard

J'\**'~\-.** - ........'-

... ·..v,...**~"'-:~/** 

### \**""::~:i-,/.r~~ ._~.----~~~~**  )**""-'V',,');~"\** 

# t {' "J



### . i!f\ 

# ·,-··r'· \,,- \u..••

# 1.

" 'j. \ .

.**;-~-.** - ----A...-

__, " ,...<



## ..**~_** 

## \. --( , \ '\1 •.**~,,~\lllilv_'~<,** /" ·:"k.':tf 

### \, r-·.. (;
.... /f'

_**>"'~** )'

....".-,,.

# ~~~,,-_~'_~- 

# ,:'--**~--.~LlSf,~~Z~>l** wmoo

" \,. (

.. '.
- •• ,

### ~'--'"**-\l~**

'-'-.

..?",._lr:.»--

.... r', '. \\

( -,-t; """'. "**,.:/'~'_.""""-" .,-._~.s~">.~"r';'** **'""""~**

.. Nonattainment Areas (263 entire counties) \ '... 

# >.

.... NonattainmentAreas (30 partial counties) \

...... 

### i Maintenance Areas (141 entire or partial countles)\,.:\ Partial counties, those with part ofthe county designated nonattainment and art attainment, are shown as fun counties on the ma . 

# ."".

.,Jf. "i

Figure 3: 8-Hour Ozone Nonattainment Areas

9 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division



### 1.4. Ozone Transport Conclusions from the DMA/NFR Photochemical Modeling The DMAlNFRphotochemical model domain was defined on a nested 36-kilometer (km), 12 km, and a 4 km nested-grid structure. This structure was utilized in conjunctionwith the Comprehensive Air-quality Model with extensions (CAMx) air quality model (ENVIRON, 2008). CAMx, SMOKE (Coats, 1996), and CONCEPT MS (Loomis et aI., 2005) air quality and emissions modeling was performed for the June-July 2006 period. Nested 36/12/4 km modeling domains were used in the Denver 8-hour ozone modeling study. The CAMx model was first applied to the 36 km continental U.S. domain using boundary conditions (BCs) from a global climate air quality model. The CAMx 2006 and 2010 base case modeling results from the 36 km continental U.S. domain simulation were then processed to generate BCs for the CAMx 12/4 km domain (Figure 4) for the 2006 12/4 kmbase case and 2010 12/4 km base case and sensitivity simulations. The CAMx simulations for the 12/4 km domains were run using two-way interactive grid nesting (i.e., pollutants canflow backand forth between the 12 km and 4 km domains to account for recirculation). The larger 36kmdomain was selectedto address the impact ofboundary conditionuncertainties for the FrontRange area ofColorado, as APCD was concerned there may be transport from Southern California and Texas. The 12 km grid resolution domain essentially covers the central Rocky Mountain States orportions thereof(i.e., Arizona, Colorado, NewMexico, Utah and Wyoming.) The4 km nested-grid covers most ofthe state ofColorado.
480 I 

### J ( 360 

### 1---

­

- -.,' l r I , I 240 120­

o
-120
-240 

### / L----

# T -

--**--.------L=t~** 

# \,' j 

# I i : ! I , ! 

### i

, , ;'A

__ \" r 

### ,j 

## -.L.. CAMx

### 4~m ' 

# :::" J' 

# j ; CAM'12k: l I" ',',' " ' 'I' "! 'I 'I' ' , ""I', -1680-1560-1440-1320-1200-1080 -960 -840 -720 -600 -480 ·360 -240 -120 0 120 240 Figure 4. Nested 12/4 km modeling domains for the DenverCAMx air quality and SMOKEemissions modeling.

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- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division



### 1.4.1. Emission Inventories and 2006 and 2010 Base Case The photochemical modeling for the "2010base case" emissions scenario performed for the DMAINFR Ozone SIP process demonstrates compliance in the Front Range Region with the 8-hour0.08 ppm ozone NAAQS. Control measures in place in 2006 and assumed for 2010 include: 1. Federal tailpipe standards and regulations, including those for small engines and non-road mobile sources. Credit is taken for these federal requirements but they are not part ofthe Colorado SIP. The credits change from 2006 to 2010 as the United States Environmental ProtectionAgency (EPA) Tier II and low sulfur gasoline standards become effective. 2. Air Quality Control Commission RegulationNo. ll--coveringthe Automobile Inspection and Readjustment (A.I.R.) program in place during the 2006 ozone season, which includes an enhanced InspectionlMaintenance (11M). For 2006, a maximum of 10% fleet coverage is assumed, and for 2010, a maximum of50% fleet coverage is assumed for the remote sensing clean screen program in the Denvermetro area (DMA) based on RegulationNo. 11. 3. Air Quality Control CommissionRegulations No.3, No.6, No.7, and Common Provisions--covering gasoline station and industrial source control programs. The Common Provisions, Parts A and B ofRegulationNo.3, and the volatile organic compounds (VQC) control requirements ofRegulation No.7 are already included inthe approved SIP. Regulation No.6 and Part C ofRegulationNo.3 implement the federal standards ofperformance for new stationary sources and the federal operating permitprogram. This reference to RegulationNo.6 and Part C of RegulationNo.3 shall not be construed to meanthat these regulations are included in the SIP. 4. Since 2004, gasoline sold in the Denver metro area during the summer Reid Vapor Pressure (RVP) ozone season (June 1to September 15) has been subjectto a national RVP limit of7.8 pounds per square inch (psi) to reduce fuel volatility. For ethanol-blended fuels, the RVP limit is 8.8 psi due to the federal 1.0 psi RVP waiver for ethanol. Since 1991, gasoline sold in the Larimer and Weld area during the summer ozone season (June 1to September 15) has been subject to a national RVP limit of9.0psi to reduce fuel volatility. Forethanol-blended fuels, the RVP limit is 10.0 psi due to the federal 1.0 psi RVP waiver for ethanol. For 2006, the RVP ofgasoline for the Denvermetropolitan portion of nonattainment areawas determined by survey to be at 8.2 psi, with an ethanol market share of60%, and for the Larimer and Weldportion ofthe nonattainment areathe RVP was determined to be 8.4 psi with the same ethanol share of60%. For purposes ofthe base case 2010 mobile source inventory, the RVP ofthe base 11 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division gasoline is assumed to be 7.8 psi for the Denver metropolitanportion of nonattainment area, with an ethanol market share of85%, and for the Larimer and Weld portion ofthe nonattainment areathe RVP was assumed to be 9.0 psi with an ethanol share of25%. 5. The EPA approved the EAC Ozone Action Plan (OAP) on August 19,2005. The OAP included an amendmentto Regulation No.7 requiring the reduction offlash emissions ofvolatile organic compounds from condensate collection, storage, processing and handling operations by May 1,2005. This initial rule required the installationofairpollution controltechnology to achieve a system-wide 47.5% reduction from uncontrolled emissions ofvolatile organic compounds from new and existing oil and gas exploration and production operations located withinthe 8-hour ozone nonattainment area designated by EPA for operators with total emissions greater than 30tons per year. The 2006base case estimate was developed from actual reported emissions based onthe system-wide 47.5% reduction requirement. 6. In February 13,2008,the EPA approvedrevisions to RegulationNo.7to require the system-wide reduction ofcondensate tank flash VOC emissions of75% for the 2007 ozone seasonby May 1, 2007 and 78% reduction for the 2012 ozone season, withtechnology that achieves a 95% reduction in VOC emissions. The 2010 base case emissions estimate assumes the 75% system-wide reduction requirement. 7. The effect ofEPA final locomotive Tier 3 standards were considered and included, where appropriate, inthe 2010 area source estimates. Tier4 10comotive standards do not go into effect until 2015 and therefore were not included in the 2010 inventories. All ofthe inventories inthis 8-hour Ozone Attainment SIP were developed using EPA approved emissions modeling methods, including EPA's MOBlLE6 model and local VMT data for on-road mobile source emissions, EPA'snon-road model and local demographic information for area and off-road sources, and reported actual emissions for point sources. Estimates for future emissions are based onthe above-mentioned tools and the EPA's Economic Growth and Analysis System (EGAS) model for estimating future point sources activity, VMT growth for on-road mobile sources, and 2010 and 2012 demographic data for off-road and area sources. The technical support document contains detailed information onmodel assumptions and parameters for each source category. Highway mobile source emissions are from the ENVIRON Consolidated Community Emissions Processing Tool (CONCEPT) model inventory, which is based on DRCOG VMT data and MOBILE6 inputdataprovided by APCD and expandedto the entire NAA based on VMT from the NorthFront Range Transportation and Air Quality Planning Council and CDOT. Non-road source emissions are from the EPANon-Road Model. This model includes the impactoffuture controls on non-road engines, which is used in equipment suchas lawn and garden equipment and construction equipment. Oil and gas source emissions are from 12 DRAFT
- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment IAir Pollution Control Division
the revised Independent Petroleum Association ofMountain States (IPAMS) inventory, and were projected to 2010 using the methodology in the IPAMS projection methodology document. The IPAMS inventory was sponsoredby the IPAMS and is Phase III ofa regional oil and gas emission inventory for the Inter-Mountain Westjointlywith the Western Regional Air Partnership (WRAP). Non-oil and gas area source emissions (including heating, consumer solventuse, aircraft and railroads, etc.) are from the 2002 EPANational Emissions Inventory (NEI), grown to 2006 and 2010 by population growth from data from the State Demographer. Consumer solvent emission reductions based on 75% ofthe per-personreductions listed in the EPA May 30, 2007 Emission Reduction CreditMemo were applied to the projected 2010 nonoil and gas area source inventory. A check on the non-oil and gas area sources estimates comparing the recently available 2005 NEI emissions data is shown later in this document. An inventory completed in 2005 for DenverInternational Airport (OIA) was used for aircraft and airport non-road source emissions from DIAfor both 2006 and 2010. Non-oil and gas point source emissions were grown to 2010 by the EPA EGAS economic model, and by adding sources for which permits have been issued. Emissions ofVOC and nitrogen oxides (NOx) from biogenic sources have been generated by the Model ofEmissions ofGases and Aerosols from Nature (MEGAN) Biogenic Emissions Model using land cover database ofbiomasstype and density and hourly meteorology data. The National Center ofAtmospheric Research (NCAR) has produced a global data base oflanduse data, the MEGAN Driving Variable Database Version 1.2, for use with MEGAN. Surface temperatures are provided by the Mesoscale Meteorological Model (MM5) modeling. Summaries ofthe VOC and NOx base case inventories for the nonattainment areafor 2006 and 2010 are presented in Table 6. Emissions ofNOx and VOCs are in tons peraverage episode day. Additional detail on the categories ofemissions can be found in the TSO. Wildfire emissions, though not included in tables, have been considered for the background ozone concentrations in the modeling effort. Wildfire emissions can vary significantly on a day-to-day basis depending on conditions.

13 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

Table 6. Base Case Inventories for 8-Hour Ozone DMAINFR NAA Photochemical Modeling (tons per average episode day) 2006 2010 Source eateaory NOx: voe


# . NOx : voe 

# · · Point Sources Electric Generation Units (EGU) 55.6 0.7 58.5 : 1.6 External Combustion Boilers 9.5 0.4 10.0 1 0.5 Industrial Processes 12.5 10.2 14.0 : 11.0 Petroleum and Solvent Evaporation 0.3 19.0 0.3 : 22.0 Other 3.1 1.8 36: 2.0 Point Sources Subtotal 81.0 32.1 86.4 37.0 Oil & Gas Point & Area Sources Condensate Tanks 126.5 129.6 Other O&G Point Sources 22.6 6.8 23.6 8.6 Pneumatic Devices (Area Source) 24.8 31.1 Unpermitted Fugitives (Area Source) 16.2 20.4 Other Area Sources 17.1 10.8 22.5 137 O&G Point & Area Sources Subtotal 39.7 185.2 46.2 203.3 Area Sources Personal Care Products 7.1 7.0 Household Products 21.4 17.9 Automotive Aftermarket Products 11.9 13.0 Architectural Coatings 20.1 16.8 Aircraft 7.4 1.3 8.2

. 1.5 Railroad 12.8 05 13.8 0.6 Other CoatingslPesticides/Cooking/ Miscellaneous. 3.9 41 Area Source Subtotal 20.2 66.3 22.1 61.0 Non-Road Mobile Sources Agricultural Equipment 70 0.9 6.3 0.7 Airport EqUipment 0.7 0.1 0.6 0.1 Commercial Equipment 5.3 6.2 5.1 7.0 Construction and Mining Equipment 35.7 5.5 31.2 4.5 Industrial Equipment 10.5 2.4 6.9 1.4 Lawn and Garden EqUipment (Commercial) 9.4 35.9 8.9 281 Lawn and Garden Equipment (Residential) 1.2 7.5 1.2 11.8 Boats/Recreational EquipmenUMiscellaneous 07 6.9 0.8 78 Non-Road Mobile Source Subtotal 70.5 65.3

1655 129.7 165.5 129.7 376.8 478.6

53.0 694.0 429.8 1172.6 61.0 61.3

1229 : 109.2 122.9 : 109.2 338.5 : 471.8

53.0 : 694.0 

# · 391.5 : 1165.8 On-Road Mobile Sources On-Road Mobile (including vehicle refueling) On-Road Mobile Subtotal Anthropogenic Total Biogenic Total Anthropoaenic & Bioaenic Total

14 DRAFT
- State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section I IO (a)(2)(D)(i)
- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

1.4.2. Discussion of2010 Base Case CAMxModelingResults Currently, Colorado'shighest emissions density is along the FrontRange. As shown in Figure 5 Photochemical Modeling done for the DMA/NFR SIP process showsthatthe highest 2010 ozone design values along the foothills west ofDenver andFort Collins. Ozone concentrations decrease rapidly to the east ofDenver. The maximumprojected 2010 base case 8-hour ozone Design Value of84 ppb occurs at both the Rocky Flats North and Fort Collins Westmonitoring sites. Asthis value is 84 ppb or lower, the 2010 base case modeling results pass the EPA modeled attainment demonstration test. Although the EPA 8-hour ozone projectionprocedure is to truncate the final projected DVFfor comparisons with the NAAQS, the projected 2010 base case future years design value is 84.9 ppb (Morris, et aI, 2008a).

.' "*Itt**~._',** .....

/"0 

# l-**b::~':f.,,;,)**

, Oerwet1l4km_dorn_OV

- ---, , --1 BASE DVF 

# - l1li

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) Figure 6 presentsthe ozone source apportionmentresults, including the boundary conditions. The boundaryconditions (BCs) showthe contribution from sources outside the 12 km domain (see Figure 4) for a given high ozone day (results vary by day). Onthis day, 15 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division
ofthe 76.1 ppb ofozone estimated at the monitor, approximately 48 ppb was transported into the 12 km domain and approximately 8ppb was attributedto sources in the sevencounty Denver Metro area (Morris, et aI, 2008a) while the rest was from other counties in Colorado or from other states. This suggests that, on this day, ozone was generated primarily by global/continental scale "background" and local sources ofemissions in the Denver Metro area. Transport from nearby states was relatively small.

runl6c.osaUy20 10.1204 060729 (2006210) Metric-03M Average >= 70.0 PPB Total Ozone 76.1 (ppb)

- Receptor rfno 72 64 56

.-.. .0 p.. 8 48 <) 40 0 u <l! Q 0 t'l 0 32 24 Ie !!II!I Be • EGU • NonEGU lIlII! Area OiIGas • Nonroad Motor Veb.

- BioFire

16 8 (L



### __**,...,e..-_--._~** 0 

### g; 23 o o 00+ + L> L> + '-' r.:I N l:Il rn [II z E-< ..: OSAT Source Regi8bs Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions. Conclusions from ozone source apportionment results (Morris, et aI, 2008a) vary by day and by location. However, several overall trends emerged, namely:

• Regional ozone transport into the 12 km domain is the largest contributor, often accounting for more than two-thirds ofthe total ozone; • Atthe Denver Metropolitan monitors the largest contributors are Denver Metropolitan metro area motor vehicle and non-road sources; • At the Fort Collins and Greeley monitors, the largest contributorstend to be Larimer and Weld County motor vehicles, non-road sources and oil and gas sources, and Denver Metropolitan sources; • The majority ofthe ozone formed is attributable to anthropogenic NOx emissions.
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- State ofColorado Implementation Plan to Meetthe Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division
In interpreting these results, it is importantto keep in mind that the source apportionment results are based onthe Denver SIP 2006 modeling episode and are meteorologically dependent For instance, the source apportionment modeling in support ofthe Denver Early Action Compactusing a 2002 ozone episode (Morris, et aI, 2004a) showed more impact from sources in northern Colorado in the DenverMetropolitan area. Other ozone transport studies also confirm that Denveris impacted by ozone from areas well outside ofColorado. A report sponsored by the Western States Air Resources Council (WESTAR) indicates that, when ozone is greaterthan 85 ppb in Denver, natural background accounts for 37.5% ofthe total concentration, transported anthropogenic generated ozone is 37.5%, and the local anthropogenic ozone contribution is about 25% (MacDonald, et. aI, 2006). A common theme at all ozone monitors is that a majority ofthe peak 8-hour ozone is due to ozone transportfrom sources outside ofColorado and outside the 12km domain boundary. Source apportionmentmodeling indicatesthat transport into the region accounts for approximately 60-75% ofthe ozone formation in the DMAINFR. This indicates that the DMAINFR is more ofa receptor ofozone and ozone precursors rather than a producer of ozone and precursors that transports ozone to areas outside ofthe FrontRange. While the modeling suggests that the transport ofozone and/or ozone precursors is a significantissue in the west, the magnitude ofozone transport from Colorado to other states is too lowto significantly contribute to nonattainment in, or interfere with maintenance by, any other state with respectto the 0.08 ppm ozone NAAQS.

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- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division



### 1.5. Denver Metro Area/North Front Range Ozone Nonattainment Area Contribution to Downwind Locations As part ofthe DenverEAC, source apportionment modeling was conducted to evaluate the spatial extent ofthe 8-hour ozone impacts due to emissions from various source regions in Colorado. A similar analysis was not done as part ofthe DMA/NFR ozone SIP analysis, however, a similar conclusion would be expected. The conclusion is that ozone formed specifically from sources inthe DMA/NFRnonattainment area decreases rapidly in concentration overthe eastern plains ofColorado. Therefore, the photochemical modeling that was done for boththe DMA/NFRozone SIP and the DenverEAC suggestthat ozone and/or ozone precursors from the Front Range do not contribute significantly to downwind monitors in other states. Figure 7 displays the spatial extent ofthe 8-hour ozone concentrations that occurred between 10am and 6pm local time (the time whenthe daily maximum 8-hour ozone typically occur) onJune 27, 2002 through July 1,2002 due to all emissions (anthropogenic and biogenic) from the DMA. As shown in Figure 7, which represents a high ozone episode in Denver, the DMA can contribute approximately 10 ppb ofozone at the eastern border ofColorado. However, the concentration gradient falls offquickly and emissions from the DMA are not expected to be a significant contributor to any ozone nonattainment areadownwind ofthe Front Range. Weld, Elbert, Morgan, Larimer, EI Paso and other counties contribute even less ozone to the Colorado border states with a maximum contribution of 5-10 ppb.

18 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

10-000

$.000

0,000 I PPB Conlribulions 10 S·h,' Owne

0.000 1 PI'S**Cont1"ibution~** 10g·h" (hone from Denver M'tropolilanHllil C.AAl><**'.~.02lOOl** <nll4l12.3grd

Contributions 10 8-hrOzone ''''>Im [lflW'I'**~tll** i)JlnHu.'"l**~\t\!'. CAM''oI'10~**  1001 cntl4

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...**O.oOO;i'(l_:)R).M~** 7.8.211 at(:l6;J3 Figure 7: Spatial extent ofthe 8-hour ozone concentrationsthat occurred between lOam and 6pm local time on June 27, 2002 through July 1,2002

19 DRAFT

- State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division 

### 1.6. Section 11O(a)2 - Ozone Transport Conclusions With respect to the 0.08 ppm ozone NAAQS, emission control programs in the Colorado SIP are expected to adequately protectneighboring states from interstate transport of ozone, per Clean AirAct (CAA) Section II0(a)(2)(D)(i). Ambient monitoring data in and around Colorado support the assertionthat Colorado does not contribute significantly to nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm ozone NAAQS. Specifically: 1. A review ofrecent ozone observations from the EPA AQS database shows that, with the exception ofa single monitor in Jefferson County, Colorado (i.e., Rocky Flats North), all monitoring sites in Colorado and adjacent states that are likely to be impacted by Colorado demonstrated attainment ofthe 0.08 ppm 8-hour ozone NAAQS for the three year period of2005-2007. Since ozone monitors in adjacent states comply with the 0.08 ppmNAAQS, it logically follows that Colorado does not cause or contribute to monitored violations or interfere with maintenance ofthe 0.08 ppmozone NAAQS in any other state. 2. For Rocky Flats North, which is the only monitor in Colorado that has levels above the 0.08 ppm ozone NAAQS, the preliminary three-year average (2006-2008) fourth high value is 0.086 parts per million (ppm), which is only slightly above the 0.08 ppm ozone NAAQS. 3. Observations from current networks showthat the highest ozone levels in Colorado occur along the Colorado Front Range and not in other areas ofColorado. 4. Ozone monitoring data from the surrounding states that are most likely to be impacted by Colorado (i.e., Nebraska, Kansas, New Mexico, Wyoming, and Utah) showthat none ofthe monitors exceed the 0.08 ppm 8-hour ozone standard. Since the areas represented by these monitors are in monitored attainment, it is highly unlikely that existing 0.08 ppmozone nonattainment areas beyondthese areas are significantly affected by emissions from Colorado. The nearest 0.08 ppmozone nonattainment areas to DMAlNFRNonattainment Areaare: a. Phoenix, Arizona (Basic Area for 8-Hour ozone) at a distance of586 miles; b. Las Vegas, Nevada (Basic Area for 8-hour ozone) at a distance of628 miles; c. Dallas, Texas (Moderate 8-hour ozone nonattainment area) at a distance of 663 miles; and d. St. Louis, Missouri (Moderate 8-hour ozone nonattainment area) at a distance of796 miles. Photochemical modeling and other technical analyses performed for the DenverEarly Action Compact (EAC) and the DenverMetro Area and North Front Range (DMAlNFR) 8-hour Ozone SIP support the assertion that Colorado does not contribute significantly to

20 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment I Air Pollution Control Division
nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm ozoneNAAQS. Specifically: 1. The Denver 8-hour Ozone SIP photochemical modeling for 2010 and the associated weight ofevidence analyses suggest that the DMAlNFRnonattainment area and downwind areas already comply or will comply with the 0.08 ppm ozone NAAQS by 2010. 2. Photochemical modeling shows that elevated ozone concentration levels generated from local emissions decrease rapidly with distance. 3. A review ofphotochemical modeling performedfor both the DMAlNFR Ozone SIP andthe DenverEAC, including boundary condition analyses, suggests that the magnitude ofozone transport from Colorado to other states is too low to significantly contribute to nonattainment in, or interfere with maintenance by, any other state with respectto the 0.08 ppm ozone NAAQS. In summary, a review ofmonitoring data, photochemical modeling, and weight ofevidence analyses generated for the DMAINFR SIP process suggests that the transport ofozone and ozone precursors from Colorado does not cause or significantly contribute to nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm 8-hour ozone NAAQS. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour

. Ozone NAAQS.

21 DRAFT

- State ofColorado Implementation Plan to Meetthe Requirements of Clean Air ActSection 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division 

# 2. REFERENCES Coats, C.l. Jr. "High-performance algorithms in the Sparse Matrix Operator Kernel Emissions (SMOKE) modelingsystem."Proc. NinthAMSJoint Conference onApplications of Air PollutionMeteorology withAWMA. Amer. Meteor. Soc., Atlanta, GA, 584-588. 1996. ENVIRON. User's Guide

- Comprehensive Air Quality Model with Extensions

- Version 4.40. ENVIRON International Corporation, Novato, CAhttp://www.camx.com. February 2008. Loomis, C., l. Wilkinson, J. Haasbeek, A. Pollack and M. Jansen. 2005. "ConCEPTConsolidatedCommunityEmissionsProcessing Tool, An Open-Source Toolfor the Emissions Modeling Community." Presented at the 14thInternational Emission Inventory Conference "Transfonning Emission Inventories

- Meeting Future ChallengesToday", Las Vegas, Nevada, April 11- 14. <http://\vww.epa.gov/ttn/chieflconferencc/ci14/sessionlllloomis.pdf> MacDonald, C., Miller, D., Raffuse, S., 2006. Regional and Local Contributions to Peak Local Ozone Concentrations in Six Western Cities. Sonoma, Technology, Inc., Petaluma, CA. Prepared for WESTAR Council ofGovernments

.. May 16 Morris R, E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008a. 2010 Ozone Projections for the 2010 Base Case and2010Sensitivity Tests and2010 Ozone Source ApportionmentModelingfor the Denver 8-Hour Ozone State Implementation Plan. ENVIRON International Corporation, Novato, California. Prepared for DenverRegional Air Quality Council (RAQC), Denver, Colorado. September 8. Morris R, E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008b. 2010 Ozone AttainmentDemonstration Modelingfor the Denver8-Hour Ozone State Implementation Plan Control Strategy. ENVIRON International Corporation, Novato, California. Prepared for DenverRegional Air Quality Council (RAQC), Denver, Colorado. September 22. Morris, RE., G.E. Mansell, E. Tai, D.A. McNally and T.W. Tesche. 2004a.Air Quality ModelingAnalysis for the DenverEarlyAction Compact: Ozone SourceApportionment Modelingfor the DenverEAC. Prepared for the Colorado Department ofHealth and Environment and DenverRegional Air Quality Council, Denver, Colorado. Prepared by ENVIRON International Corporation, Novato, CA. May 31

..

22 DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-Hour OzoneStatement ofBasis, Specific Statutory Authority and Purpose

THIS STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND PURPOSE SUPPORTS REVISIONS TO COLORADO'S IMPLEMENTATION PLAN REGARDING THE INTERSTATE TRANSPORT OF AIR POLLUTANTS (HEREINAFTER "INTERSTATETRANSPORT SIP"). THESE REVISIONS APPLY TO COLORADO'S STATE IMPLEMENTATION PLAN ONLY AND DO NOT REVISE ANY REGULATION. THEREFORE, THIS STATEMENT IS NOT REQUIRED BY THE ADMINISTRATIVE PROCEDURES ACT. NEVERTHELESS, THE COMMISSION OFFERS THIS STATEMENTTO FURTHERTHE UNDERLYING OBJECTIVES OF THE APA AND THE COLORADO AIR POLLUTION PREVENTION AND CONTROL ACT.
BASIS
THEAIR QUALITY CONTROL COMMISSION HAS ADOPTED REVISIONS TO THE INTERSTATE TRANSPORT SIPTO ADDRESS COMMENTS FROM THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (EPA) FINDING THE SIP DEFICIENT.
IN FEBRUARY OF 2007THE COMMISSION ADOPTED AN INTERSTATE TRANSPORT SIP FOR OZONE AND PM2.5. THIS SIPWAS TRANSMITTED TO EPA IN JUNE OF 2008. SINCETHAT SIPPRECEDED THE 2007 OZONE SEASON, IT DID NOT REFLECT THE MONITORING RESULTS FROM THAT PERIOD, INCLUDING THE VIOLATION OF THE 1997GROUND-LEVEL OZONE NATIONAL AMBIENT AIR QUALITY STANDARDS (NAAQS) AND EPA's SUBSEQUENT DESIGNATION OF NONATTAINMENT FOR THE DENVERMETRO AREA AND NORTH FRONTRANGE (DMAINFR). EPA OFFERED INFORMAL COMMENTS ON THE INTERSTATE TRANSPORT SIP, OPINING ON THIS AND OTHER PERCEIVED DEFICIENCIES. IN RESPONSE, THE COMMISSION ADOPTED THE FOREGOING REVISIONS TO ADDRESS DEFICIENCIES PERTAINING TO OZONE.
STATUTORY AUTHORITY
THE STATUTORY AUTHORITY FOR THESE REVISIONS IS SET FORTH IN § 25-7-105(1), c.R.S. OF THE COLORADO AIR POLLUTION PREVENTION AND CONTROL ACT ("ACT"), WHICH AUTHORIZES THE COMMISSION TO ADOPT A STATE IMPLEMENTATION PLAN THAT MEETS ALL REQUIREMENTS OF THE CLEAN AIR ACT.
PURPOSE
THE PURPOSE OF THIS INTERSTATE TRANSPORT SIP REVISION IS TO ADDRESS EPA COMMENTS THAT THE SIP DOES NOT ADEQUATELY ADDRESS ANY ADVERSE IMPACTS THE DMAlNFRNONATIAINMENT AREA MAY HAVE ON OTHER STATES' COMPLIANCE WITH THE OZONE NAAQS. PURSUANT TO 42 U.S.C. § 741O(A)(2)(D)(I), COLORADO'S INTERSTATE TRANSPORT SIPMUST DEMONSTRATE, AMONG OTHER THINGS, THAT COLORADO'S AIR POLLUTION SOURCES WILL NOT CONTRIBUTE SIGNIFICANTLY TO NONATTAINMENT, OR INTERFERE WITH MAINTENANCE BY, ANY OTHER STATE OF THE OZONE NAAQS. THE COMMISSION HAS REVISED THE OZONE TRANSPORT SECT10N OF THE INTERSTATE TRANSPORT SIPTO INCLUDE ANALYSIS, MONITORING AND MODELING INFORMATION DEMONSTRATING THAT COLORADO, INCLUDING THE DMAlNFRNON-ATTAINMENT AREA, DOES NOT CONTRIBUTE SIGNIFICANTLY TONONATTAINMENT OR INTERFERE WITH MAINTENANCE BY ANY OTHER STATE WITH RESPECT TO THE 0.08 PPM OZONE NAAQS. Regulation No. 7 Page 1IN A SEPARATE ACTION, THE COMMISSION HAS ADOPTED THE OZONE ATTAINMENT PLAN TO ADDRESS EPA's NON-ATTAINMENT DESIGNATION OF THE DMAINFRAREA. THE OZONE ATTAINMENT PLAN AND THE INTERSTATE TRANSPORT PLAN, TOGETHER, FORM THE BASIS FOR A CONCLUSION THAT COLORADO'S SIP SATISFIES CLEAN AIRACT REQUIREMENTS PERTAINING TO GROUND-LEVEL OZONE.

COLORADO AIR QUALITY CONTROL COMMISSION
ADOPTED: DECEMBERXX, 2008



### Regulation No.7 Page 2

# Parties Hearing Documents (this includes a list ofthe parties, the parties prehearing statements and rebuttal statements, and any orders by the Commission)

# Parties Hearing Documents

PARTY

- Air Quality Control Commission o 

### Orderto Deny Motionto Bifurcate Air Pollution Control Division o 

### Motionto Bifurcate Anadarko Petroleum Company, Noble Energy, Inc., Whiting Oil and Gas Company, and Williams ProductionRMT Company o 

### Responseto Bifurcation WildEarth Guardians o 

### Response to Bifurcation

## RECEIVE[j1 BEFORE THE AIR QUALITY CONTROL COMMISSION 

## NOV 28 2008 STATE OF COLORADO A1RQUAUTY -----------------------------;oNT.u:::RQl:-::::=::COMt"ISS10 

### ORDER TODENYMOTIONTO BIFURCATE

- November28,2008

IN THE MATTER OF PROPOSED REVISIONS TO THE AMBIENT AIR QUALITY STANDARDS REGULATION, REGULATIONNUMBERS 3,·7, AND 11 FORTHE DENVERMETROPOLITAN & 

### NORTH FRONTRANGE AREA OZONE ACTION PLAN.
This matter came before the Hearing Officer on a motion ofthe Colorado DepartmentofPublic Health and Environment, AirPollution Control Division ("Division"), to bifurcate the proceeding and separately considertheproposed Interstate Transport SIP revision. The public has received notice thatthe Interstate Transport SIP may be revised on a statewide basis to address the interstatetransport ofozone as a part ofthe Commission's consideration ofthe proposed ozone action plan and accompanying proposed regulatory revisions. Thepublic has had an opportunity to reviewthe proposed revisions to the Interstate Transport SIP and provide commentregarding those revisions. Afterconsidering the motion and the responses, and having been otherwise fully informed, hereby orders that the motion to bifurcate the hearing be denied. It

### is also orderby the Hearing Officerthat: 1. The Division will provide a revised Chapter V, Section H ofthe proposed Ozone ActionPlan that is responsive to the comments ofEPA to the extentthat they remain withinthe scope ofthe noticed rulemaking hearing. The Division will provide this response to the Commission Office and the parties to the rulemaking hearing by 3:00 PM, Monday, December 1,2008. 2. The Divisionresponse, along withthe Motion to Bifurcate, the responses ofthe parties andthis order shall be provided to the Commissioners as soon as practicable after its receipt. 3. The parties to the hearing may provide a response to the Division's December 1, 2008 filing. The parties will provide any responses to the Division's December I, 2008 filing by 1:00 PM, Friday, December 5, 2008. The parties will provide their responses to the Commission office and to each otherparty to the rulemaking hearing andthe Division. The Commission Office will provide the response of the parties to the Commissioners as soon as is practicable aftertheir receipt.

### 4. The Commission shall considerthe interstate transportplanprovisions ofthe proposed ozone actionplan in the scheduled rulemaking hearing, but shall take a separate action inregard to the proposed interstate transportprovisions at the conclusion ofthe rulemaking hearing for the proposed ozone actionplanin response to the comments ofEPA.
So Ordered, 

### this 28th 

### day ofNovember 2008.

Commissioner BarbaraRoberts Hearing Officer

## RECEIVED BEFORE THE AIR QUALITY CONTROL COMMISSION 

## WOV 

## 13 2008 STATE OF COLORADO AlRQUALID 

### carontalIMISSlQI\' AIR POLLUTION CONTROLDIVISION'S MOTION TO BIFURCATE INTERSTATE TRANSPORT SIP REVISION IN THE MATTER OF PROPOSED REVISIONS TO THE AMBIENT AIR QUALITY STANDARDS REGULATION, REGULATION NUMBERS 3. 7, AND II FOR THE DENVER METROPOLITAN &NORTH FRONT RANGE AREA OZONEACTION PLAN.
The Colorado DepartmentofPublic Health and Environment, Air Pollution Control Division ("Division"), through the Office ofthe Attorney General, moves the Commission to bifurcate the hearing in this matter, and in supportofthis motion, offers the following: 1. During the September 18th Request for Hearing on theproposed Ozone Action Plan, at the request ofthe Division, the Commission added Section H. "Section IIO(a)2­ Transport Requirements," to Chapter V ofthe 8-hourOzone State Implementation Plan, PhotochemicalModelingandOther Weight of EvidenceAnalyses ForAttainment Demonstration. The Division proposed this section to address EPA as well as stakeholder comments concerningozonetransport and to ensurethat the Ozone SIP has no deficiency concerning the Interstate Transport ofozone. 2. Colorado is required to submit an Interstate Air PollutantTransport SIP (Transport SIP) pursuant to the Clean Air Act, 42 U.S.c. Section 741 0(a)(2)(D)(i). 3. The Commission adopted a Transport SIP in Februaryof2007. That plan was submitted to EPA in Jtme of2008. 4. EPA has provided preliminarycomment to the Division indicating that the Transport SIP has deficiencies. EPAhas also commented that the Transport SIP should be separated from the Ozone SIP because the plans are separate elements ofthe State Implementation Plan. 5. Based on this comment, the Division proposes that the Commission bifurcate the proceeding, separate the TransportSIP from the Ozone SIP and considerTransport SfP in a separate hearing during the Commission's December meeting. The scopeofnoticed

. revisions remains the same. The Transport SIP document is attached hereto. 6. The public, including all parties to this proceeding, has received notice ofa pending proposal on the Transport SIP via the Notice ofHearing for the Ozone Action Plan, which states: The ozone action plan proposes to modify the provisions ofthe Interstate Air Pollutant Transport State Implementation Plan element adopted by the Commission in February 2007. bynoting that the proposed maintenance plan would prevent the Colorado Front Range from contributing significantly to ozone non-attainment orinterfere with (ong-term maintenance ofthe national ozone standard in any otherstate.7. The Notice ofHearing in this matterput the public on notice that the Commission would be considering modifications to the Transport SIP. Ifthe notice and opportunity to comment are to have any meaning, changes to the original proposal mustbe reasonably expected. As long as any changes to the noticed proposal are a logical outgrowth ofthe original proposal, the changes comport with administrative procedure. Long Island Care at Home, Ltd. v. Coke, 127 S.Ct. 2339,2351 (U.S., 2007). Therefore, the Division respectfully requests that the hearing officerissue an order bifurcating this proceeding and schedule a separate hearing during the Commission's Decembermeeting, and thereafter considering the attached revisions to the Transport SIP.

DATEDthis 13th dayofNovember2008.

JOHN W. SUTHERS Attorney General

... =­

# ~- /., . ?" THOMAS A. ROAN, 30867* Assistant Attorney General Environmental Quality Natural Resources and Environment Section Attorneys for AIR POLLUTION CONTROL

DIVISION 1525 Shennan Street, 5th Floor Denver, Colorado 80203 Telephone: (303) 866-5280 *CounseI ofRecord

2CERTIFICATE OF SERVICE Iherebycertify on this 13th dayofNovember, 2008, a true and correct copyofthe foregoing Motion to Bifurcate Interstate Transport SIP Revision and CAA 110 (a)(2)(D)(i) InterstateTransport Draft was served on the following via electronic mail: JeremyNichols WildEarth Guardians 1536Wynkoop, Suite 302 Denver, CO 80202 jnichols(ffwiIdeanhguardialls,org Michael E. Korenblat JayChristopher Director, Legal Affairs Manager, Environmental SuncorEnergy (U.S.A.) Inc. SuncorEnergy(U.S.A.) Inc. 7800 East Orchard Road, Suite 300 Denver West Refinery Greenwood Village, CO 801 I I 5801 Brighton Blvd. mkorenblat@suncor.com Commerce City, CO 80022 jchristopher@sllllcor.com Allan L. Hale AmandaA. Bradley MatthewW. Spengler Hale Friesen, LLP 1430 Wynkoop St., Suite 300 Denver, CO 80202 ahale@halefriesell.colll abradley@.halcfricscn.com !11spenglerC{lihalefriesell.co

### m Daniel J. Schnee El PasoWestern Pipelines 2 North Nevada, No. 1414 Colorado Springs, CO 80903 daniel.sclmec(aklpaso.colll Ted Orf Dianna L. Orf Orf& OrfPC 1410 Grant St., Suite C-207 P.O. Box 102036 Denver, CO 80250-2036**Jaw({i.~orfco.l1e[** (counsel for the Colorado Mining Association) Stan Dempsey, Jr. Colorado Petroleum Association 1580 Lincoln St., Suite 1125 Denver, CO 80203sran(2i.coloradopetrolclimassociatioll.org Jeffrey W. Schwarz CarverSchwarz McNab & Bailey, LLC 1600 Stout St., Suite 1700 Denver, CO 80202 b-c**Il\varz@..ck~m** b.colll (counsel for DCP Midstream, LP) Linda L. Rockwood Eric J. Triplett Faegre & Benson, LLP 1700 Lincoln St. 3200 Wells Fargo Center Denver, CO 80203 lrockwood@faegre.com etripIett(a!raegre.com (counsel for Public Service Companyof Colorado (PSCo) Steve Cook DenverRegional Council ofGovemments 1290 Broadway, Suite 700 Denver, CO 80203 scook(chlrcog.org Kevin Lynch Environmental Defense Fund RockyMountain Office 2334 North Broadway Boulder, CO 80304 klvllch@edf.org Kenneth A. Wonstolen Benjamin Vetter Fulbright & Jaworski LLP 370 I

## t h St., Suite 2150 Denver, CO 80202 k.!Vollstolen(U;fuIbril!ht.co1l1 bvcttcncUuIbnllht.com (counsel for the Colorado Oil & Gas Association) John R. Jacus Todd A. Weaver AbbyJ. Gaffney Davis Graham & Stubbs LLP 1550 I

## t h St., Suite 500 Denver, CO 80202 Lauren C. Buehler Xcel Energy, Inc. 1225 Seventeenth St., Suite 900 Denver, CO 80202 Laurcn.C.Buehler(a!xcelenergy.com

Meg Collins, President Colorado Oil & Gas Association 1660 Lincoln St., Suite 2710 Denver. CO 80264 !1l9ll.COllins((licoga.orgjohn.jacus@dgslaw.com todd.weaver((i;dgslavv'.com abby.garfney(ci,dgslaw.com (counsel for Anadarko Petroleum Corporation, Noble Energy, Inc., Whiting Oil and Gas Corporation, and Williams Production RMT Company) Colin G. Harris Holme Roberts & Owen LLP 1801 13lh St., Suite 300 Boulder, CO 80302 colin.harris(c(hro.com (counsel for EnCanaOil 

### & Gas (USA) Inc.) Pamela H. Milmoe Air/WasteProgram Coordinator BoulderCountyPublic Health 3450Broadway Boulder, CO 80304 pmilmoe@bouidercolillty.org

Richard L. Griffith Richard L. Griffith, LLC 1580Lincoln St., Suite 700 Denver, CO 80203 ricklgri**f(a~~aol.com** (counsel for Colorado Ethanol Group) Kenneth Lloyd Regional Air Quality Council 1445 Market St., Suite 260 Denver, CO 80202 klloydui'faqc.org Suzette Mallette North Front Range Metropolitan Planning

Organization 419 Canyon Fort Collins, CO 80521 smalktte(cLnfimpo.org Diane M. Blieszner EnCana Oil & Gas (USA) Inc. 370 17th St., Suite 1700 Denver, CO 80202**dialle.blicsznen'(l~EnCana.co11l** GreggThomas SabrinaM. Williams DenverEnvironmental Health 201 W. Colfax Ave., Dept. 1009 Denver, CO 80202 Gregg.thornas({udenvergov.org**Sabrina.williams@denv~[gQv.org** (representing Local Government Coalition)Barbara Roberts, Commission Hearing Officer Ashley Campsie, Commissioner Rad Byerly, Commissioner Doug Lempke, Administrator Theresa Martin, Program Assistant Air Quality Control Commission 4300CherryCreek Drive South EDO-AQCC-A5 Denver, CO 80246 barbarawrobgrts(Zi;comcasl.nct**ashlev.campsie(a~eh2m.coln** hrbverl**v~l;emai** l.eom 90uglas.lcmpkca-vstate.co.LLs theresa.marlin(custalc.eo.lIs Kirsten King Mike Silverstein AirPollution Control Division 4300 Cherry CreekDrive South APCD Bl Denver, CO 80246 kirsten.k**ing(iL~'Slatc.co.lIs** mikc.siIvcrstcin@:statc.co.us Jerry Goad, Commission Attorney William Allison, Division Attorney Office ofthe Attorney General 1525 Shennan St. Denver, CO 80203 jerry.goad('(t:state.eo.us 

### william.alliSOrl((ustale.co.us Kerri Fiedler US EPA Region 8 1595 Wynkoop St. 8P-AR Denver, CO 80202-1129 IIedlcr.kerri<iiepa.go\:

## ReCEIVED UEe 

## 01 200B**~jkOUAUTY** PROPOSALTO REVISE COLORADO's INTERSTATE TRANSPORT**IMPLEMENTATl~.r~:U):MlISSDi** PLAN FORTHE 1997 8-HOUR OZONE NAAQS
Overview: In September 2008, the Air Pollution Control Division (Division) included interstate ozone transport summary language and technical support information as part ofthe proposed Denver Metro AreaINorth Front Range 8-hour OzoneAction Plan. Atthat time, the Division found that Colorado air pollution sources do not contribute significantly to nonattainment ofor interfere with maintenance with the 1997 8-hour ozone National Ambient Air Quality Standard of0.08 parts permillion in another state. This finding is required by the Clean Air Act, Section 110 (a)(2)(D)(I) regarding interstate transport. As a result ofits review ofthe Ozone Action Plan, EPA noted that the Interstate Transport Plan does not belong in the Ozone Action Plan because ofthe Plan's limited focus on the Front Range region and notthe entire State, as is required. The Division concurred with this finding and then asked the Commission to bifurcate the hearing so that the ozone element ofthe Interstate Transport Plan would be heard and considered separately. The Commission Pre-hearing officer has since determined that it is appropriate to hear the State-wide Ozone Interstate Transport Plan as part ofthe proposed Ozone Action Plan public hearing, but there would be a separate motion to approve the Transport Plan. The Division has removed the ozone transport summary language from the Ozone Action Plan and has created a stand-alone State-wide Ozone Interstate Transport Plan (attached). This standalone plan has been available to the public as part ofthe Ozone Action Plan's technical support document since November 6,2008. Background: In November 2006, the AirQuality Control Commission adopted an Interstate Transport Plan addressing both the 8-hourozone NAAQS and for PM-2.5 NAAQS. This SIP document was transmitted to EPA following legislative review in June 2007. EPA has since provided informal comments on November 12,2008 (via email) identifying deficiencies in the ozone and PM-2.5 Interstate Transport Plan. EPA'scomments on the ozone portion ofthe Plan and the Division's response are as follows:
I. EPA (pg. 1): Colorado must demonstrate that it will not contribute significantly to nonattainment or interfere with maintenance ofthe 8-hour ozone NAAQS. Division: The revised document for ozone makes an affirmative declaration that is summarized in the conclusion ofthe document (Section 1.6). 2. EPA (pg 1): The 2007 Plan referred to Colorado's deferred nonattainment status and doesn'treference subsequent violations ofthe 8-hour ozone NAAQS (over a year after the hearing). EPA requests this section be rewritten. Division: The revised document does address the violations ofthe ozone NAAQS.3. EPA: The previous document used the Early Action Compact (EAC) modeling as a technical basis for concluding there are no interstate impacts. EPA requests this section be updated. Division: The revised document has been updated to include an analysis ofresults from the Ozone Action Plan base case modeling and recent monitoring datato concludethat Coloradowill not cause or significantly contribute to nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm 8-hour ozoneNAAQS

.. 4. EPA: EPA points outthedated language in the Plan aboutthe EAC. They request that this be updated. Division: The revised document does remove all inconsistent language and out dated references to the EAC. 5. EPA: EPA requests thatthe state specifically address why, with the exceedances mentioned, Colorado does not contribute to nonattainment in other states. Division: The revised document has been restructured to provides answers to this question in Section IA.2,Section 1.5, and in the Conclusion. 6. EPA: EPA has requested that the State remove outdated language on the Clean Air Interstate Rule (CAIR) modeling from the narrative. Division: References to the CAIR modeling have been removed. 7. EPA: EPA has requested the State remove language relating to "maintenance plans" and use the term, "maintenance". Division: References to "maintenance plans" havebeen removed from the revised document. The analysis and language in the revised document address "maintenance" as required by Clean AirAct, Section 110 (a)(2)(D)(I) regarding interstate transport.
8. EPA: EPA has commented thatthe State should referto the specific standard in question, in this case the 1997 8-hour NAAQS for ozone. Division: This has been addressed in the revised document. 9. EPA has commented on the unclear graphs in the original report. Division: The graphs in the revised document have been fixed to be more readable. EPA's comments on the PM2.5 and visibility portions ofthe Plan are not addressed atthis time and will be addressed at a later date.The Division requests thatthe Commission approve the State-wide Ozone Interstate Transport State Implementation Plan.Bi-frication'motion to be denied Overview document from the Division: Description ofwhat we've done Response to comments Remove text from OAP made a stand alone document Monday: Denial ordergoes out wi original bi-frication motion, two Party responses to the motion. And the Division's overview paper and the Plan

### State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i) Interstate Transport Regarding 8-Hour Ozone

DRAFT November 5, 2008 Colorado Department of Public Health and Environment Air Pollution Control Division 4300 Cherry Creek Drive South Denver, Colorado 80246Colorado DepartmentofPublic Health and Environment/ AirPollution Control Division

i DRAFT

- State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublicHealth and Environment/ AirPollution Control Division


# Table ofContents I. OZONE-SPECIFIC PROVISIONS TO MEETTHEREQUIREMENTS OFCAA 1I0(A)(2)(D)(I)­ INTERSTATE TRANSPORT 1 1.1. INTRODUCTION I 1.2. COLORADO OZONE MONITORING NETWORK 2 1.3. OZONE MONITORING NETWORK IN NEARBY STATES 7 104. OZONETRANSPORTCONCLUSIONS FROM TIlE DMAINFR PHOTOCHEMICAL MODELING 10 1.4.1. EmissionInventories and2006and2010 Base Case

_ 11 1.4.2. Discussion 0/2010Base Case CAMx ModelingResults 15 1.5. DENVERMETROAREAINORTH FRONT RANGE OZONENONAITAINMENT AREA CONTRIBUTION TO DOWNWINDLOCATIONS 18 1.6. SECTION I IO(A)2

- OZONETRANSPORT CONCLUSIONS 20 2. REFERENCES 22 

# List ofTables Table 1: 2008 I-HourOzone Monitored Concentration (updated through Sept. 30, 2008) 4 Table 2: 2008 8-HourOzone Monitored Concentration (updated through Sept. 30, 2008) 5 Table 3: Monitored 8-HourDesign Value Using the 3-Year(2006-2008) Average ofthe Fourth Maximum Ozone Concentration 6 Table 4: 2005-2007 3-YearFourthHighest Average Monitoring Concentrations from Kansas, Nebraska, NewMexico, Utah and Wyoming (see Table 5 for additional data) 7 Table 5. 2005-2007 3-YearFourth Highest Average Monitoring Concentrations from Kansas, Nebraska, NewMexico, Utah and Wyoming (see Table 4 for additional data) 8 Table 6. Base Case Inventories for 8-HourOzone DMAlNFR

### NAA Photochemical Modeling 14


# List of Figures Figure 1. 

### Location ofFrontRange Ozone Monitors 2 Figure 2. Location ofStatewide Ozone Monitors 3 Figure 3: 8-Hour OzoneNonattainmentAreas 9 Figure 4. Nested 12/4 

### km modeling domains for the Denver CAMx airquality and SMOKE emissions modeling 10 Figure 5. Projected 2010 8-hour ozone DesignValues (DVF) 15 Figure 6. Rocky Flats North source apportionment for 29July including boundary conditions 16 Figure 7: Spatial extent ofthe 8-hourozone concentrations that occurred between lOam and 6pm local time onJune 27, 2002 through July 1, 2002 19

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- Interstate Transport Regarding 8-HourOzoneColorado DepartmentofPublic Health and Environment/ Air Pollution Control Division

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- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air PollutionControl Division



## 1. Ozone-Specific Provisions to Meet the Requirements of CAA 11O(a)(2)(D)(i) - Interstate Transport 1.1. Introduction The purpose ofthis document is to provide a technical basis for the State ofColorado's planto meet the requirements ofthe Clean Air Act Section 110 (a)(2)(D)(i) Interstate Transport requirements regarding the 0.08 parts permillion (ppm) 8-HourOzone National Ambient Air Quality Standard (NAAQS). This addresses the applicable components of 110(a)(2)(D)(i)demonstrating adequate provisions to preventemissions from Colorado from interfering with attainment ormaintenance ofthe federal ozone NAAQS in any other state. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour Ozone NAAQS. This document replaces the sectiontitled "Ozone-Specific Provisions" in the document "State ofColorado Implementation Planto Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)

- Interstate Transport Regarding 8-HourOzone and PM2.5 NAAQS." Currently, the Denverarea is the only area in U.S. Environmental Protection Agency (EPA) Region VIII that is designated as nonattainment for the 8-hourozone NAAQS of 0.08 ppm. Inthis report, relevant informationfrom the DenverMetropolitanArea and North Front Range (DMA/NFR) 8-hour Ozone State Implementation Plan (SIP) process, the Denver Early Action Compact (EAC) process, ambient ozone data for Colorado, ambientozone data for nearby states from the EPA Air Quality System (AQS) database, and other information is used to demonstrate that Colorado does not contribute significantly to nonattainment in, orinterfere withmaintenance by, any other state withrespect to the 0.08 ppm ozoneNAAQS.

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### 1.2. Colorado Ozone Monitoring Network The 2007/2008 ozone ambient air monitoring network in the Denverarea and along the northern Front Range consists of 13 stations operatedby the Colorado AirPollution Control Division (APCD) and one station operatedby the National Park Service (NPS) in Rocky MountainNational Park. Therehave been other stations thathave operated in the past. The geographical distribution ofthe Front Range monitors is presented inFigure 1. As shown in Figure 1, the ozone monitors are primarily located in urbanized areas along the FrontRange corridor. The monitors are located in areas where the highest ozone concentrationshave been monitored historically and where elevated ozone is expectedto occur. High ozone concentrations along the Front Range occur nearthe areas with high emissions density and dense population. In addition, elevated ozone is observed along elevatedterrain to the westofthe DMAlNFRNonattainment Area. All ofthese monitors are designated by the U.S. Environmental Protection Agency as "equivalent" analyzers and follow all quality assurance requirements as specified in 40 CFRPart 58, Appendix A.

Figure I. Location ofFront Range Ozone Monitors

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### Figure 2 shows other ozone monitoring sites that exist inColorado for 2008. These are operated by either Colorado, the Southern Ute Tribe, or various Federal agencies. All of these sites use monitors that are designated as "equivalent" analyzers by the U.S. Environmental Protection Agency. As shown, most ofthe sites are in the southwest comer ofColorado, either within ornearthe San Juan oil and gas development area.

Figure 2. Location ofStatewide Ozone Monitors 

### Table 1, Table 2, and Table 3presentthe monitoring data for the DMAINFR

### NAA monitoring sites (including the NPS Rocky MountainNational Park monitoring site) as well as for other sites in Colorado. In Table 3, the fourth maximum 8-hourozone concentrations along withthe 3-yearaverage ofthe fourth maximum concentrations at each site are presented. As shown in both Table I and Table 3, the Denver area is currently meeting the 8-hourand former I-hourozoneNAAQS for all sites, except for the 8-Hour NAAQS at Rocky Flats North witha designvalue of0.86 ppm.

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Table I: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008)
AQS Number Site Name 1stMax I-Hour (ppm) Date 1stMax I-Hour 2ndMax I-Hour (ppm) Date 2nd Max I-Hour 3rdMax I-Hour (ppm) Date 3rd Max I-Hour 4thMax I-Hour (ppm) Date 4th Max I-Hour 08-001-3001 Welby 0.100 08/29 0.095 08/05 0.092 07/10 0.089 06/20 08-005-0002 • Highland 0.065 04/04 0.064 04/08 0.064 04/18 0.062 04/19 08-013-0011 S. Boulder Creek 0.089 07/10 0.089 07125 0.086 07/16 0.085 05/31 08-031-0014 Carriage 0.094 08/05 0.090 08/29 0.089 07/10 0.085 06120 08-031-0025 •• Denver

- Animal Shelter 0.100 07/10 0.098 08/05 0.087 06/20 0.087 08/24 08-035-0004 Chatfield State Park 0.101 07/10 0.098 06120 0.095 08129 0.092 08124 08-041-0013 Colo. Spgs.

­ Academy 0.085 OS/24 0.083 07/10 0.082 08/06 0.080 07/18 08-041-00.16 Manitou Springs 0.087 OS/24 0.085 08/06 0.083 07/10 0.083 07/11 08-045-0012 •• Rifle

- Health 0.081 07/09 0.080 07/10 0.075 08/19 0.074 07/11 08-059-0002 Arvada 0.093 08/05 0.093 08/29 0.092 07/10 0.088 07/25 08-059-0005 Welch 0.102 07/10 0.090 06/20 0.088 08/05 0.088 08/29 08-059-0006 Rocky Flats - N 0.088 07/10 0.088 07/18 0.088 08129 0.087 07/02 08-059-00II NREL 0.097 08/29 0.093 07/10 0.092 08/05 0.092 08/24 08-067-7001 ••• So. Ute'- Ignacio 0.076 06/04 0.075 05/31 0.073 05/03 0.072 05/3 08-067-7003 ••• So. UteBondad 0.080 06/04 0.078 05/31 0.077 OS/27 0.071 04/21 08-067-???? USFS

- Shamrock 0.081 06/04 0.079 06/10 0.077 02/29 0.077 05/30 08-069-0007 Rocky Mountain Nat'l Park 0.092 07/09 0.090 07/31 0.090 08/28 0.085 OS/22 08-069-00II Ft. Collins

- West 0.093 08/19 0.092 07/09 0.092 07/18 0.088 07/24 08-069-1004 Ft. Collins

- CSU 0.082 08/19 0.080 07/09 0.079 08/30 0.078 07/24 08-077-0020 •• Palisade

- Water 0.081 07/09 0.079 07/10 0.075 07/08 0.074 07/05 08-083-0006 •• Cortez 0.078 07/23 0.074 07/13 0.072 08/05 0.071 07/25 08-083-0I0 1 Mesa Verde Nat'l Park 0.075 05/01 0.075 06/04 0.074 05/31 0.072 04/30 08-123-0009 Greeley

- Weld Tower 0.094 08/20 0.092 07/24 0.089 08/01 0.087 08/04
NOTES: • Highland site shut down on 4/21/08 for approx. 6-months. •• Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Watercommenced on 5/30/08 and Cortezcommenced on 6/17/08

. ••• Southern Ute sites data only thru 6/30/08.

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- Interstate Transport Regarding 8-HourOzoneColoradoDepartment ofPublic Health and Environment/ Air Pollution Control Division


### Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008)
AQS Number Site Name 1stMax 8-Hour (ppm) Date IstMax 8-Hour 2nd Max 8-Hour (ppm) Date 2nd Max 8-Hour 3rd Max 8-Hour (ppm) Date 3rd Max 8-Hour 4th Max 8-Hour (ppm) Date 4th Max 8-Hour 08-001-3001 Welby 0.085 07/10 0.083 08/29 0.077 01/18 0.076 06/20 08-005-0002 

### *Highland 0.062 04/04 0.060 04/08 0.060 04/18 0.059 04/05 08-013-0011 S. Boulder Creek 0.080 07/10 0.076 05/31 0.076 07/09 0.076 07/18 08-031-0014 Carriage 0.081 07/10 0.075 08129 0.073 06/20 0.072 07126 08-031-0025 

### ** Denver

- Animal Shelter 0.086 07/10 0.072 08/29 0.071 07/13 0.070 07/26 08-035-0004 Chatfield State Park 0.090 07/10 0.082 06/30 0.080 06/20 0.080 06127 08-041-0013 Colo. Spgs.

­ Academy 0.078 OS/24 0.077 07/10 0.073 08/06 0.070 07/18 08-041-0016 Manitou Springs 0.080 OS/24 0.076 07/10 0.074 07/11 0.072 07/31 08-045-0012 

### **Rifle

- Health 0.076 07/09 0.076 07/10 0.069 08/19 0.066 071I3 08-059-0002 Arvada 0.081 08/29 0.080 07/10 0.077 06/20 0.074 08/05 08-059-0005 Welch 0.095 07/10 0.079 06/20 0.077 07/18 0.073 08/19 08-059-0006 Rocky Flats - N 0.083 07/10 0.080 07/18 0.079 05/3J 0.079 08/29 08-059-00II NREL 0.085 071I0 0.085 08/29 0.077 06120 0.076 06/02 08-067-700I 

### *** So. UteIgnacio 0.069 06/04 0.067 06/10 0.066 05/10 0.066 06/13 08-067-7003 

### *** So. UteBondad 0.073 06/04 0.067 OS/27 0.067 05/31 0.067 06/05 08-067-???? USFS

- Shamrock 0.074 06/04 0.073 06/10 0.071 06/13 0.069 05/30 08-069-0007 Rocky Mountain Nat'l Park 0.081 07/09 0.077 OS/25 0.077 07/31 0.076 05/31 08-069-00II Ft. Collins

- West 0.081 07/18 0.079 07/09 0.078 OS/25 0.076 07/24 08-069-1004 Ft. Collins

- CSU 0.070 OS/25 0.070 07/09 0.068 07/18 0.066 05/31 08-077-0020 

### ** Palisade

- Water 0.077 07/09 0.075 07/10 0.070 05/31 0.070 07/29 08-083-0006 

### ** Cortez 0.067 08/02 0.066 07123 0.065 08/07 0.064 08/05 08-083-0101 Mesa Verde Nat'l Park 0.071 06/04 0.070 04/30 0.069 04/21 0.069 06/10 08-123-0009 Greeley

- Weld Tower 0.077 07/24 0.076 08/20 0.075 07/26 0.073 08/01 NOTES: 

### * Highland site shut down on 4/21/08 for approx. 6-months. 

### ** Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Watercommenced on 5/30/08 and Cortezcommenced on 6/17/08. 

### *** Southern Ute sites data only thru 6/30/08.

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Table 3: Monitored 8-HourDesign ValueUsingthe 3-Year (2006-2008) Average ofthe Fourth Maximum Ozone Concentration

Site Name AQS# 2006 

## 7 Maximum

8-Hour Average Value (ppm) 2007 

## 7 Maximum

8-Hour Average Value (ppm) 2008 

## 7 Maximum

8-Hour Average Value(ppm) Design Value (2006

­ 2008) 3-Year Average 4th Maximum Value (ppm) Welby 08-001-3001 0.069 0.070 0.076 0.071 *Highland 08-005-0002 0.081 0.075 0.059 0.071 S. BoulderCreek 08-013-0011 0.082 0.085 0.076 0.081 Carriage 08-031-0014 0.072 0.076 0.072 0.073 **Denver

- Animal Shelter 08-031-0025 

### --­ --­ 0.070 

### --- Chatfield State Park 08-035-0004 0.086 0.082 0.080 0.082 USAF Academy 08-041-0013 0.072 0.072 0.070 0.071 Manitou Springs 08-041-0016 0.076 0.072 0.072 0.073 **Rifle

- Health 08-045-0012 

### --­ --­ 0.066 

### --­ Arvada 08-059-0002 0.082· 0.079 0.074 0.078 Welch 08-059-0005 0.081 0.080 0.073 0.078 Rocky Flats

- North 08-059-0006 0.090 0.090 0.079 0.086 NREL 08-059-0011 0.083 0.085 0.076 0.081 *** So. Ute

- Ignacio 08-067-7001 

## --­ --­ 0.066


### --­ *** So. Ute

- Bondad 08-067-7003 0.063 0.071 0.067**0~067** USFS

- Shamrock 08-067-???? 0.074 0.069 0.069 0.070 Rocky Mountain Nat'l Park 08-069-0007 0.076 0.078 0.076 0.076 FortCollins

- West 08-069-0011 0.087 0.085 0.076 0.082 FortCollins

- CSU 08-069-1004 0.078 0.069 0.066 0.071 ** Palisade

- Water 08-077-0020


## --­ --­ 0.070


### --­ ** Cortez 08-083-0006 

### --­ --­ 0.064 

### --­

.Mesa Verde Nat'l Park 08-083-0101 0.074 0.070 0.069 0.071 Greeley

- Weld Tower 08-123-0009 0.082 0.074 0.073 0.076 NOTES: 

### * Highland site shutdown on 4/21/08 for approx. 6-months. *

### * Denver

- Animal Shelter site commenced on4/22/08, Rifle

- Healthcommenced on 6/20/08, Palisade

- Water commenced on 5/30/08 and Cortezcommenced on 6/17/08. 

### *** SouthernUte sites data only thru 6/30/08. Ignacio data invalid for 0112005 to 08/2007.

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### 1.3. Ozone Monitoring Network in Nearby States Table 4 and Table 5 present 8-hourozone monitoring data from the surrounding states of Nebraska, Kansas, NewMexico, Wyoming, and Utah. Table 4 and Table 5 showthat none ofthe monitors in surrounding states exceedthe 8-hourozone standard. Therefore, to the extentthatthe network is representative ofall areas, it canbeconcluded that the DMA/NFR sources do not significantly contributeto the 8-hour ozone standard violations at these down wind locations oreven further downwind.
Table 4: 2005-2007 3-YearFourth Highest Average Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming (seeTable 5 for additional data)

SiteID State County EPA Re2ion 2005 8-hr Ozone 4th Max

(ppm) 2006 8-hr Ozone 4th Max

(ppm) 2007 8-hrOzone

4th Max

(ppm) 3-yr Avg. of 4th Max

(ppm) 20-045-0004 KS Douf:das 7 0.073 0.081 End 2007 N/A 20-091-00I0 KS Johnson 7 0.081 0.076 0.071 0.076 20-103-0003 KS Leavenworth 7 0.077 0.074 0.080 0.077 20-107-0002 KS Linn 7 0.075 0.079 0.070 0.074 20-173-000I KS Sedgwick 7 0.065 0.065 0.059 0.063 20-173-0010 KS Sedgwick 7 0.074 0.073 0.060 0.069 20-191-0002 KS Sumner 7 0.078 0.080 0.070 0.076 20-195-0001 KS Trego 7 0.071 0.076 0.068 0.071 20-209-0021 KS Wyandotte 7 0.079 0.081 0.073 0.077 31-055-0028 NE Douglas 7 0.069 0.072 0.066 0.069 31-055-0032 NE Douglas 7 0.067 0.066 0.056 0.063 31-055-0035 NE Douglas 7 0.070 0.067 0.061 0.066 31-109-0016 NE Lancaster 7 0.056 0.056 0.054 0.055 35-001-0019 NM Bernalillo 6 0.073 0.073 0.070 0.072 35-001-0023 NM Bernalillo 6 0.072 0.073 0.069 0.071 35-001-0024 NM Bernalillo 6 0.074 0.074 0.068 0.072 35-001-0027 NM Bernalillo 6 0.073 0.072 0.071 0.072 35-001-0029 NM Bernalillo 6 0.071 0.070 0.067 0.069 35-001-1012 NM Bernalillo 6 0.077 0.047 0.074 0.066 35-001-1013 NM Bernalillo 6 0.077 0.071 0.071 0.073 35-001-1014 NM Bernalillo 6 0.072 0.072 0.064 0.069 35-013-0008 NM Dona Ana 6 0.070 0.072 0.068 0.070 35-013-0017 NM Dona Ana 6 0.070 0.073 0.070 0.071 35-013-0020 NM Dona Ana 6 0.072 0.072 0.068 0.070 35-013-0021 NM Dona Ana 6 0.076 0.080 0.076 0.077 35-013-0022 NM Dona Ana 6 0.070 0.073 0.073 0.072 35-013-0023 NM Dona Ana 6 0.066 0.070 0.062 0.066

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Table 5.2005-20073-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming (see Table 4 for additional data)

Site ID State County EPA Resdon 2005 8-hr Ozone 4th Max

(ppm) 2006 8-hr Ozone 4th Max

(ppm) 2007 8-hrOzone

4th Max

(ppm) 3-yr Avg. of 4th Max

(ppm) 35-015-1005 NM Eddy 6 0.067 0.076 0.066 0.069 35-017-1003 NM Grant 6 0.071 0.067 0.062 0.066 35-025-0008 NM Lea 6 0.074 0.075 0.064 0.071 35-029-0003 NM Luna 6 Start 2006 0.053 0.062 

### N/A 35-043-100I NM Sandoval 6 0.069 0.064 0.063 0.065 35-043-1003 NM Sandoval 6 0.075 0.074 0.071 0.073 35-043-9004 NM Sandoval 6 0.076 0.072 0.067 0.071 35-045-0009 NM San Juan 6 0.075 0.063 0.069 0.069 35-045-0018 NM San Juan 6 Start 2006 0.079 0.079 

### N/A 35-045-1005 NM San Juan 6 0.072 0.071 0.073 0.072 49-003-0003 UT Box Elder 8 0.079 0.078 0.077 0.078 49-003-700I UT Box Elder 8 0.075 0.076 0.078 0.076 49-005-0004 UT Cache 8 0.069 0.073 0.074 0.072 49-011-0004 UT Davis 8 0.092 0.082 0.082 0.085 49-035-0003 UT SaltLake 8 0.083 0.084 0.082 0.083 49-035-2004 UT Salt Lake 8 0.086 0.082 0.082 0.083 49-035-3006 UT Salt Lake 8 0.082 0.082 0.079 0.081 49-035-3007 UT Salt Lake 8 0.085 0.080 0.080 0.081 49-035-3008 UT SaltLake 8 0.080 0.082 0.079 0.080 49-037-0101 UT SanJuan 8 0.069 0.070 0.072 0.070 49-045-0003 UT Tooele 8 0.080 0.079 0.076 0.078 49-049-0002 UT Utah 8 0.078 0.074 0.075 0.075 49-049-5008 UT Utah 8 0.080 0.077 0.078 0.078 49-049-5010 UT Utah 8 0.080 0.079 0.077 0.078 49-053-0130 UT Washington 8 0.091 0.072 0.071 0.078 49-057-0007 UT Weber 8 0.081 0.083 0.080 0.081 49-057-1003 UT Weber 8 0.084 0.083 0.082 0.083 56-005-0123 WY Campbell 8 0.063 0.072 0.072 0.069 56-005-0456 WY Campbell 8 0.063 0.065 0.072 0.066 56-035-0098 WY Sublette 8 0.075 0.069 0.068 0.070 56-035-0099 WY Sublette 8 0.079 0.072 0.067 0.072 56-035-0100 WY Sublette 8 0.066 0.074 0.066 0.068 56-037-0200 WY Sweetwater 8 Start 2006 0.067 0.064 

### N/A 56-039-1011 WY Teton 8 0.060 0.069 0.065 0.064 

### Figure 3 presents a map ofall the U.S. nonattainmentareas. Since the surrounding states ofKansas, Nebraska, Wyoming, Utah, and NewMexico do not have violations the 8-hour NAAQS for ozone, it canbe reasonably concludedthat Colorado sources do not significantly affect the ozone nonattainment areas even further downwind such as Dallas8 DRAFT

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ForthWorth and St. Louis nonattainment areas. In addition, it is unlikely that Colorado would significantly affect nonattainment areas that are typically "upwind" such as Las Vegas and Phoenix. However, it is recognizedthat, under the types ofsynoptic scale meteorological regimes that occurduring someregional ozoneepisodes, simple terms like "upwind" and "downwind" may not be applicable. Thus, photochemical modeling is needed to study the distribution ofozone under a variety ofmeteorological regimes.

Nonattainment and Maintenance Areas in the U. S. 8-hour Ozone Standard

Figure 3: 8-HourOzone Nonattainment Areas

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# --- -120 -240 Colorado Department ofPublic Health and Environment/ Air Pollution Control Division



### 1.4. Ozone Transport Conclusions from the DMA/NFR Photochemical Modeling The DMAlNFRphotochemical model domain was defined on a nested 36-kilometer (km), 12 km, and a 4 km nested-grid structure. This structure was utilized in conjunction with the Comprehensive Air-quality Model with extensions (CAMx) airqualitymodel (ENVIRON, 2008). CAMx, SMOKE (Coats, 1996), and CONCEPTMS (Loomis etaI., 2005) airquality and emissions modeling was performed for the June-July 2006 period. Nested 36/12/4 km modeling domains were used in the Denver 8-hourozone modeling study. The CAMxmodel was first applied to the 36 km continental U.S. domain using boundary conditions (BCs) from a global climate airquality model. The CAMx 2006 and 2010 base case modelingresults from the 36 km continental U.S. domain simulation were then processedto generate BCs for the CAMx 12/4 km domain (Figure 4) for the 2006 12/4 km base case and 2010 12/4 km base case and sensitivity simulations. The CAMx simulations for the 12/4km domains were run using two-way interactive grid nesting (i.e., pollutants can flow back and forth betweenthe 12 km and4 km domains to account for recirculation). The larger 36km domain was selectedto address the impact ofboundary condition uncertainties for the FrontRange area ofColorado, as APCD was concerned there may be transport from SouthernCaliforniaandTexas. The 12 km grid resolution domain essentially covers the central Rocky Mountain Statesorportions thereof(i.e., Arizona, Colorado, NewMexico, Utah and Wyoming.) The4 km nested-grid covers most ofthe state ofColorado.
480 360 

### --I I 240 

# I L 

# r-i

!----t:=

__

## ~;;;C;;AM~X**~4k~1** m:=!lI 

# ._J I I 120

0 

### I 

# I I 

# \L

I 

# \1 I 

# I

I

## ~_. 

# i-I \-\ I I

. / CAMx 12k'

> j -1680-1560-1440-1320-1200-1080 -960 -840 -720 -600 -480 -360 -240 -120 0 120 240 I J'

Figure 4. Nested 12/4 km modeling domains for the DenverCAMx air quality and SMOKE emissions modeling.

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### 1.4.1. Emission Inventories and 2006 and 2010 Base Case The photochemical modeling for the "2010base case"emissions scenario perfonned for the DMAlNFR Ozone SIP process demonstrates compliance in the Front Range Region withthe 8-hour 0.08 ppm ozone NAAQS. Control measures in place in 2006 and assumed for 2010 include: 1. Federal tailpipe standards andregulations, including those for small engines and non-road mobile sources. Credit is taken for these federal requirements but they are not part ofthe Colorado SIP. The credits change from 2006 to 2010 as the United States Environmental ProtectionAgency (EPA) Tier II and low sulfur gasoline standards become effective. 2. Air Quality Control CommissionRegulationNo. 11--covering the Automobile Inspection and Readjustment (A.I.R.) program inplace during the 2006 ozone season, which includes an enhancedInspection/Maintenance (11M). For 2006, a maximum of 10% fleet coverage is assumed, and for 2010, a maximum of50% fleet coverage is assumed for the remote sensing clean screenprogram in the Denvermetro area (DMA) based on RegulationNo. 11. 3. Air Quality Control CommissionRegulations No.3,No.6, No.7, and Common Provisions--covering gasoline stationand industrial source control programs. The Common Provisions, Parts A and B ofRegulationNo.3, and the volatile organic compounds (VOC) control requirements ofRegulation No.7 are already included in the approved SIP. RegulationNo.6 and Part C ofRegulation No.3 implement the federal standards ofperfonnance for new stationary sources and the federal operating pennitprogram. This reference to Regulation No.6 and Part C of RegulationNo.3 shall not be construed to mean that these regulations are included in the SIP. 4. Since 2004, gasoline sold in the Denvermetro area during the summerReid Vapor Pressure (RVP) ozone season (June 1to September 15) has been subjectto a national RVP limit of7.8 poundsper square inch (psi) to reduce fuel volatility. For ethanol-blended fuels, the RVP limit is 8.8 psi due to the federal 1.0psi RVP waiver for ethanol. Since 1991, gasoline sold in the Larimer and Weld area during the summer ozone season (June 1 to September 15) has been subject to a national RVP limit of9.0 psi to reduce fuel volatility. Forethanol-blended fuels, the RVP limit is 10.0 psi due to the federal 1.0 psi RVP waiver for ethanol. For 2006, the RVP ofgasoline for the Denver metropolitan portion of nonattainment area was detennined by survey to be at 8.2 psi, with an ethanol market share of60%, and for the Larimerand Weld portion ofthe nonattainment area the RVP was detennined to be 8.4 psi withthe same ethanol share of60%. For purposes ofthe base case 2010 mobile source inventory, the RVP ofthe base I1 DRAFT

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### gasoline is assumed to be 7.8 psi for the Denvermetropolitanportionof nonattainment area, with anethanol market share of85%, and for the Larimer and Weld portion ofthe nonattainment area the RVP was assumed to be 9.0 psi with an ethanol share of25%.**5~** 

### The EPA approved the EAC Ozone Action Plan (OAP) on August 19,2005. The OAP included an amendment to Regulation No.7requiring the reduction offlash emissions ofvolatile organic compounds from condensate collection, storage, processing and handling operations by May 1,2005. This initial rule required the installation ofair pollution control technology to achieve a system-wide 47.5% reduction from uncontrolled emissions ofvolatile organic compounds from newand existing oil and gas exploration andproduction operations located within the 8-hour ozone nonattainment area designated by EPA for operators with total emissions greater than 30 tons peryear. The 2006 base case estimate was developed from actual reported emissions based onthe system-wide 47.5% reduction requirement. 6. In February 13,2008,the EPA approved revisions to Regulation No.7to require the system-wide reduction ofcondensate tank 

### flash VOC emissions of75% for the 2007 ozone season by May 1, 2007 and 78% reduction for the 2012 ozone season, with technology that achieves a 95% reduction in VOC emissions. The 2010 base case emissions estimate assumes the 75% system-wide reduction requirement. 7. The effect ofEPA final locomotive Tier 3 standards were considered and included, where appropriate, in the 2010 area source estimates. Tier 4 locomotive standards do not go into effect until 2015 andtherefore were not included in the 2010 inventories. All ofthe inventories inthis 8-hourOzone Attainment SIP were developed using EPA approved emissions modeling methods, including EPA's MOBILE6 model and local VMT data for on-roadmobile source emissions, EPA's non-road model and local demographic information for areaand off-road sources, and reported actual emissions for point sources. Estimates for future emissions are based on the above-mentioned tools and the EPA's Economic Growth and Analysis System (EGAS) model for estimating future point sources activity, VMT growth for on-road mobile sources, and 2010 and 2012 demographic data for off-road and area sources. The technical support document contains detailed information on model assumptions and parameters for each source category. Highway mobile source emissions are from the ENVIRON Consolidated Community Emissions Processing Tool (CONCEPT) model inventory, which is based onDRCOG VMT data and MOBILE6 input dataprovided by APCD and expanded to the entire NAA based on VMT from the NorthFront Range Transportation and Air QualityPlanning Council and CDaT. Non-road source emissions are from the EPA Non-RoadModel. This model includes the impactoffuture controls onnon-road engines, which is used in equipment suchas lawn and garden equipment and construction equipment. Oil and gas source emissions are from 12 DRAFT

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the revised Independent Petroleum Association ofMountain States (IPAMS) inventory, and were projected to 20lOusing the methodology in the IPAMS projection methodology document. The IPAMS inventory was sponsored by the IPAMS and is Phase 

### III ofa regional oil and gas emissioninventory for the Inter-Mountain Westjointly withthe Western Regional Air Partnership (WRAP). Non-oil and gas area source emissions (including heating, consumer solventuse, aircraft and railroads, etc.) are from the 2002 EPA National Emissions Inventory (NEI), grownto 2006 and 2010 bypopulation growthfrom data from the State Demographer. Consumer solvent emissionreductions based on 75% ofthe per-personreductions listed in the EPA May 30, 2007EmissionReduction CreditMemo were applied to the projected 20I0 nonoil and gas area source inventory. A check on the non-oil and gas area sources estimates comparing the recently available 2005 NEI emissions data is shown laterin this document. Aninventory completed in 2005 for DenverInternational Airport (DIA) was used for aircraft and airportnon-road source emissions from DIA for both 2006 and 2010. Non-oil and gas point source emissions were grown to 2010by the EPA EGAS economic model, andbyadding sources for whichpermitshave beenissued. Emissions ofVOC andnitrogen oxides (NOx) from biogenic sources have been generated by the Model ofEmissions ofGases andAerosols from Nature (MEGAN) Biogenic Emissions Model using land cover data base ofbiomass type and density and hourly meteorology data. The National Center ofAtmospheric Research (NCAR) has produced a global database ofland use data, the MEGAN Driving Variable Database Version 1.2, for use withMEGAN. Surface temperatures are provided by the Mesoscale Meteorological Model (MM5) modeling. Summaries ofthe VOC andNOxbase case inventories for the nonattainment area for 2006 and 2010 are presented inTable 6. Emissions ofNOx and VOCs are in tons per average episode day. Additional detail onthe categories ofemissions can be found in the TSD. Wildfire emissions, though not included in tables, have been considered for the background ozone concentrations in the modeling effort. Wildfire emissions canvary significantly on a day-to-day basis depending onconditions.

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Table 6. Base Case Inventories for 8-HourOzone DMA/NFR NAA Photochemical Modeling (tons per average episode day) 2006 2010 SOurce Category NOx: 

## voc


# . NOx: VOC



# · Point SOurces Electric Generation Units (EGU) 55.6 : 0.7 58.5 : 1.6 External Combustion Boilers 9.5 1 0.4 10.0 ; 0.5 Industrial Processes 12.5 : 10.2 14.0; 11.0 Petroleum and Solvent Evaporation Other 0.3 ; 19.0 3.1 

## ! 1.8 0.3 : 22.0 3.6 

### 1 2.0 PointSourcesSubtotal 81.0 : 32.1

, , :
, 126.5 22.61 6.8
, 24.8 16.2 17.1 10.8 39.7 185.2 86.4 : 37.0



# · · · 129.6 23.6 8.6 31.1 20.4 22.5 13.7 46.2: 203.3 Oil & Gas Point & Area Sources Condensate Tanks OtherO&G Point Sources Pneumatic Devices (Area Source) Unpermitted Fugitives (Area Source) Other Area Sources O&G Point & Area Sources Subtotal Area Sources Personal Care Products 7.1 7.0 Household Products 21.4 17.9 Automotive Aftermarket Products 11.9 13.0 Architectural Coatings 20.1 16.8 Aircraft 7.4 1.3 8.2 1.5 Railroad 12.8 0.5 13.8 0.6 OtherCoatingslPesticides/Cooking/ Miscellaneous. 3.9 4.1 Area SourceSubtotal 20.2 66.3 22.1 61.0 Non-Road Mobile SOurces Agricultural Equipment 7.0 0.9 6.3 0.7 Airport EqUipment 0.7 0.1 0.6 0.1 Commercial Equipment 5.3 6.2 5.1 7.0 Construction and Mining EqUipment 35.7· 5.5 31.2 4.5 Industrial Equipment 10.5 2.4 6.9 1.4 Lawn and Garden Equipment (Commercial) 9.4 359 8.9 28.1 Lawn and Garden Equipment (Residential) 1.2 7.5 1.2 11.8 Boats/Recreational Equipment/Miscellaneous 0.7 6.9 0.8 7.8 Non-Road Mobile SOurce Subtotal 70.5 65.3

165.5 129.7 165.5 129.7
376.8. 478.6

63.0 : 694.0



# . 429.8 : 1172.6 61.0 61.3

122.9 109.2 122.9 109.2
338.5 471.8

53.0 694.0 391.5 1165.8 On-Road Mobile Sources On-Road Mobile (including vehicle refueling) On-Road Mobile Subtotal Anthropogenic Total BiogenicTotal AnthroPOaenic & BioaenicTotal

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### 1.4.2. Discussion of2010Base Case CAMx ModelingResults Currently, Colorado'shighest emissions density is along the FrontRange. As shown in Figure 5Photochemical Modeling done for the DMA/NFR SIP process shows that the highest 2010 ozone design values alongthe foothills west ofDenverandFort Collins. Ozone concentrations decrease rapidly to the east ofDenver. The maximumprojected 2010 base case 8-hour ozone Design Value of84 ppb occurs at both the Rocky Flats North and Fort CollinsWest monitoring sites. As this value is 84 ppb orlower, the 2010 base case modelingresults pass the EPAmodeled attainment demonstration test. Although the EPA 8-hour ozone projectionprocedure is to truncate the final projectedDVF for comparisons with the NAAQS, the projected 2010 base case future years design value is 84.9ppb (Morris, et ai, 2008a).

# ~g~~/--L-;-L--J Leg.ld 

## ***Oz~ne** Mondor 

## o o>::u1ty'_ICP 

### J 

### 0 51.",_1", 

# r------L O.m&f04km_dom_DV i**r~--",.J-l** BASE OW

_ fj$ l1(1'"= jI( c.:= 6'5 00

_ 65 :)0-< 'l'i' <,;; 1() (I (I**70ilO<~<=r500** IS 1)0< 1. <='0000 

# ···lJI 

# r I

# ··~·-T-----,---l----­ I 

# t-----_I 

# I

# ,:~I /' .--r--'­

Figure 5. Projected 2010 8-hourozone DesignValues (DVF) 

### Figure 6presents the ozone source apportionmentresults, including the boundary conditions. The boundary conditions (BCs) showthe contribution from sources outside the 12 km domain (see Figure 4) for a given high ozone day (results vary by day). Onthis day, 15 DRAFT

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- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division


### ofthe 76.1 ppb ofozone estimated at the monitor, approximately 48 ppb was transported into the 12 

### kIn domain and approximately 8ppb was attributed to sources in the sevencounty DenverMetro area (Morris, et aI, 2008a) while the rest was from other counties in Colorado or from other states. This suggests that, onthis day, ozone was generated primarily by globaVcontinental scale "background" and local sources ofemissions inthe Denver Metro area. Transport from nearby states was relatively small.

run16c.osaUy2010.1204 060729 (2006210) Metric-03M Average >= 70.0 PPB Total Ozone 76.1 (ppb)

- Receptor rfno 72 64 56 48 40 32 24 Ie • Be • EGU • NonEGU • Area • OilGas • Nonroad • Motor Veh. • BioFire

16 8 

### o t3 o o 0 + + C) u w III Z**~ ~**

GSAT Source**Regi~s** Figure 6. Rocky Flats North source apportionment for 29 July including boundary conditions. 

### Conclusions from ozone source apportionmentresults (Morris, et aI, 2008a) vary by day and by location. However, several overall trends emerged, namely:

• Regional ozonetransport into the 12 

### kIn domain is the largest contributor, often accounting for more than two-thirds ofthe total ozone; • At the DenverMetropolitan monitors the largest contributors are Denver Metropolitan metro areamotorvehicle and non-road sources; • Atthe FortCollins and Greeley monitors, the largest contributors tend to be Larimer and Weld County motorvehicles, non-road sources and oil and gas sources, and DenverMetropolitan sources; • The majority ofthe ozone fonned is attributable to anthropogenicNOxemissions.
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### In interpreting these results, it is importantto keep in mind thatthe source apportionment results are based onthe Denver SIP 2006 modeling episode andare meteorologically dependent Forinstance, the source apportionment modeling in support oftheDenver Early Action Compact using a 2002 ozone episode (Morris, et aI, 2004a) showed more impact from sources innorthern Colorado in the DenverMetropolitan area. Other ozone transport studies also confirm that Denver is impactedby ozone from areas well outside ofColorado. A report sponsoredby the Western States Air Resources Council (WESTAR) indicates that, whenozone is greater than 85 ppb inDenver, natural background accounts for 37.5% ofthe total concentration, transported anthropogenic generated ozone is 37.5%, andthe local anthropogenic ozone contributionis about 25% (MacDonald, et. aI, 2006). A commontheme at all ozone monitors is that a majority ofthe peak 8-hour ozone is due to ozone transport from sources outside ofColorado and outside the 12km domain boundary. Source apportionment modeling indicatesthat transport into the region accounts for approximately 60-75% ofthe ozone formation in the DMA/NFR. This indicates that the DMA/NFRis more ofa receptor ofozone and ozoneprecursors ratherthana producerof ozone and precursors that transports ozone to areas outside ofthe Front Range. While the modeling suggests that the transport ofozone and/orozone precursors is a significant issue in the west, the magnitude ofozone transport from Colorado to other states is too lowto significantly contribute to nonattainmentin, orinterfere with maintenance by, any other state with respectto the 0.08 ppm ozoneNAAQS.

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### 1.5. Denver Metro Area/North Front Range Ozone Nonattainment Area Contribution to Downwind Locations As partofthe DenverEAC, source apportionment modeling was conducted to evaluate the spatial extent ofthe 8-hourozone impacts due to emissions from various source regions in Colorado. A similar analysis was not done as part ofthe DMA/NFRozone SIP analysis, however, a similar conclusionwould be expected. The conclusion is that ozone formed specifically from sources inthe DMA/NFRnonattainment area decreases rapidly in concentration over the easternplains ofColorado. Therefore, the photochemical modeling that was done for both the DMA/NFRozone SIP and the DenverEAC suggest that ozone and/or ozone precursors from the FrontRange do notcontribute significantly to downwind monitors inother states. Figure 7 displays the spatial extentofthe 8-hourozone concentrations that occurred between lOam and 6pm local time (the time when the daily maximum 8-hour ozone typically occur) onJune 27, 2002 throughJuly 1,2002due to all emissions (anthropogenic and biogenic) from the DMA. As shown in Figure 7, whichrepresents a high ozone episode in Denver, the DMA cancontribute approximately 10ppb ofozone at the eastern borderofColorado. However, the concentration gradient falls offquickly and emissions from the DMA are not expectedto be a significant contributor to any ozone nonattainment areadownwind ofthe FrontRange. Weld, Elbert, Morgan, Larimer, EI Paso and other counties contribute evenless ozone to the Colorado border states with a maximum contributionof 5-10 ppb.

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S.OlIII

•.000 1'1'8 Contributionsto 3-hrOzone**fr_~~Al'** .. CAMo<votM**Zlib1<"""'''''~**

I ",,;l..=._..1

1 II Contributionsto 3-hrOzonE'

ConII1bulion,to 8-hl"Oronp



### ..... n"" Contributions to8·llr Ozone

Contribution.,to8-hr()zon('

Figure 7: Spatial extent ofthe 8-hourozone concentrations that occurred between lOam and 6pm local time on June 27, 2002 throughJuly 1,2002

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### 1.6. Section 110(a)2 - Ozone Transport Conclusions With respect to the 0.08 ppm ozone NAAQS, emission control programs in the Colorado SIP are expected to adequately protect neighboring states from interstate transport of ozone, per Clean AirAct (CAA) Section 11O(a)(2)(D)(i). Ambient monitoring data in and around Colorado supportthe assertion that Colorado does not contribute significantly to nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm ozone NAAQS. Specifically: 1. A review ofrecent ozone observations from the EPA AQS database shows that, withthe exception ofa single monitor in Jefferson County, Colorado (Le., Rocky Flats North), all monitoring sites in Colorado and adjacent states that are likely to be impacted by Colorado demonstrated attainment ofthe 0.08 ppm 8-hour ozone NAAQS for the three yearperiod of2005-2007. Since ozone monitors in adjacent states comply with the 0.08 ppm NAAQS, it logically follows that Colorado does not cause orcontribute to monitored violations or interfere with maintenance ofthe 0.08 ppm ozone NAAQS in any other state. 2. ForRocky Flats North, which is the only monitor in Colorado that has levels above the 0.08 ppm ozone NAAQS, the preliminary three-year average (2006-2008) fourth highvalue is 0.086 parts permillion (ppm), which is only slightly above the 0.08 ppm ozone NAAQS. 3. Observations from current networks showthat the highest ozone levels inColorado occur along the Colorado Front Range and not inother areas ofColorado. 4. Ozone monitoring data from the surrounding states that are most likely to be impacted by Colorado (i.e., Nebraska, Kansas, NewMexico, Wyoming, and Utah) showthat none ofthe monitors exceed the 0.08 ppm 8-hour ozone standard. Since the areas represented by these monitors are in monitored attainment, it is highly unlikely that existing 0.08 ppm ozone nonattainment areas beyondthese areas are significantly affected by emissions from Colorado. The nearest 0.08 ppm ozone nonattainment areas to DMA/NFRNonattainment Area are: a. Phoenix, Arizona (Basic Area for 8-Hour ozone) at a distance of586 miles; b. Las Vegas, Nevada (Basic Area for 8-hour ozone) at a distance of628 miles; c. Dallas, Texas (Moderate 8-hour ozone nonattainment area) at a distance of 663 miles; and d. S1. Louis, Missouri (Moderate 8-hour ozone nonattainment area) at a distance of796 miles. Photochemical modeling and othertechnical analysesperformed for the Denver Early Action Compact (EAC) and the DenverMetro Area andNorth Front Range (DMA/NFR) 8-hour Ozone SIP support the assertion that Colorado does not contribute significantly to
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### nonattainment in, orinterfere with maintenance by, any other state with respect to the 0.08 ppm ozone NAAQS. Specifically: I. The Denver 8-hour Ozone SIP photochemical modeling for 20I0 and the associated weight ofevidence analyses suggest that the DMAlNFRnonattainment area and downwind areas already comply orwill comply with the 0.08 ppm ozone NAAQS by 2010. 2. Photochemical modeling shows that elevated ozone concentration levels generated from local emissions decrease rapidly withdistance. 3. A reviewofphotochemical modelingperfonned for boththe DMA/NFR Ozone SIP andthe DenverEAC, includingboundary condition analyses, suggests thatthe magnitude ofozonetransport from Coloradoto other states is too lowto significantly contribute to nonattainment in, orinterfere with maintenance by, any other state with respectto the 0.08 ppm ozone NAAQS. In summary, a reviewofmonitoring data, photochemical modeling, and weight ofevidence analyses generated for the DMA/NFR SIP process suggests that thetransportofozone and ozoneprecursors from Colorado does not cause or significantly contributeto nonattainment in, orinterfere with maintenance by, any other state with respect to the 0.08 ppm 8-hour ozone NAAQS. This analysis does not address ozonetransport for the revised 0.075 ppm 8-Hour OzoneNAAQS.

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# 2. REFERENCES Coats, C.J. Jr. 

### "High-performance algorithms in the Sparse Matrix OperatorKernelEmissions (SMOKE) modelingsystem."Proc. NinthAMSJoint Conference onApplications of Air PollutionMeteorology withAWMA. Amer. Meteor. Soc., Atlanta, GA, 584-588. 1996. ENVIRON. User's Guide

- Comprehensive Air Quality Model withExtensions

- Version 4.40. ENVIRON International Corporation, Novato, CAhttp://www.camx.com. February 2008. Loomis, C., J. Wilkinson, J. Haasbeek, A. Pollack and M. Jansen. 2005. 

### "ConCEPT

­ Consolidated CommunityEmissionsProcessing Tool, An Open-Source Tool for the Emissions Modeling Community." Presented at the 14thInternationalEmissionInventory Conference "Transforming Emission Inventories

- Meeting Future ChallengesToday", Las Vegas, Nevada, April 11- 14.**<http://w~w.epa.gov/ttn/chief/conference/eiI4/session11/loomis.pdt>** MacDonald, C., Miller, D., Raffuse, S., 2006. Regional and Local Contributions to PeakLocal Ozone Concentrations in Six WesternCities. Sonoma, Technology, Inc., Petaluma, CA. Prepared for WESTARCouncil ofGovernments

.. May 16 Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008a. 

### 2010 Ozone Projectionsforthe 2010Base Case and2010Sensitivity Tests and2010 Ozone Source ApportionmentModelingfor the Denver8-Hour Ozone State Implementation Plan. ENVIRON International Corporation, Novato, California. Prepared for DenverRegional Air Quality Council (RAQC), Denver, Colorado. September 8. Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008b. 

### 2010 Ozone AttainmentDemonstrationModelingfor the Denver8-Hour Ozone State Implementation Plan ControlStrategy. ENVIRON International Corporation, Novato, California. Prepared for DenverRegional Air Quality Council (RAQC), Denver, Colorado. September22. Morris, R.E., G.E. Mansell, E. Tai, D.A. McNally and T.W. Tesche. 2004a.

### Air Quality ModelingAnalysis for the DenverEarlyAction Compact: Ozone SourceApportionment Modelingfor the DenverEAC. Prepared for the Colorado Department ofHealth and Environment and Denver Regional Air Quality Council, Denver, Colorado. Preparedby ENVIRON International Corporation, Novato, CA. May 31

..

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## RECEIVED**~OV** 

## 2"] 2009 AlRUUALlTY**~n** CCMo\lSSlOi' 

### BEFORETHEAIR QUALITY CONTROL COMMISSION, STATEOFCOLORADO

In the Matter ofProposed Revisions to Ambient Air Quality Standards Regulation, Regulation Numbers 3, 7, and 11 for the DenverMetropolitan and North Front Range Ozone Action Plan


### JOINTRESPONSE IN SUPPORT OFMOTIONTOBIFURCATEBY ANADARKO PETROLEUM CORPORATION,NOBLE ENERGY, INC., andWILLIAMS PRODUCTIONRMT COMPANY
Anadarko Petroleum Corporation ("Anadarko"), Noble Energy, Inc. ("Noble"), and Williams Production RMT Company ("Williams") (collectively the "Well Operators")jointly submit to the State ofColorado Air Quality Control Commission ("Commission") this Response in Support ofthe Colorado Department ofPublic Health and Environment, Air Pollution Control Division's ("Division") Motion to Bifurcatethe Interstate Transport SIP Revision ("Motion to Bifurcate"), and state as follow: 1. 

### On November 13, 2008, the Division filed its Motion to Bifurcate with the Commission requesting that the Interstate Air PollutantTransport State Implementation Plan ("Transport SIP")bebifurcatedfrom the present rulemaking process on the proposed Ozone Action Plan. 2. TheDivision's motion is based, in part, upon comments from the U.S. Environmental Protection Agency indicating that the Transport SIP should be seperated from the Ozone Action Plan because it is a separate element ofthe State Implementation Plan. 3. In response, the Division has proposed to separate the Transport SIP from the December hearing on the Ozone Action Plan, and have the Transport SIP considered during the Commission's regularDecember meeting. 4. TheWell Operators support the Division's Motion to Bifurcate as it well help to further narrow the numerous issues to be resolved by the Commission during the hearing on the OzoneAction Plan. Therefore, the Well Operators respectfully request that the hearing officer grantthe Division's Motion to Bifurcate, and issue an orderbifurcating the Transport SIP from the Ozone Action Plan proceedings and scheduling the Transport SIP for hearing during the Commission'sregular Decembermeeting.

#879403.2

### Dated this 21st day ofNovember, 2008. Respectfully submitted, sl

### John R. 

### Jacus John R. Jacus, Esq. Todd A. Weaver, Esq. Abby J. Gaffney, Esq. DAVIS GRAHAM & 

### STUBBS LLP 1550 Seventeenth Street, Suite 500 Denver, Colorado 80202 Telephone: 303-892-9400 Facsimile: 303-893-1379 john.jacus@dgslaw.com todd.weaver@dgslaw.com abby.gaffney@dgslaw.com ATIORNEYS FORANADARKO PETROLEUM CORPORATION, NOBLEENERGY, INC., AND WILLIAMS PRODUCTION RMT COMPANY

-2­

### CERTIFICATE OFSERVICE
I hereby certify that a true and correct copy ofthe attached

### JOINT RESPONSE IN SUPPORT OFMOTION TO BIFURCATE BY ANADARKO PETROLEUM CORPORATION, NOBLE ENERGY, INC., and WILLIAMS PRODUCTION RMT COMPANY was filed and servedbyelectronic mail on the 21st day ofNovember, 2008, upon the following:

Air Quality Control Commission BarbaraRoberts,barbarawroberts@gmail.com Ashley Campsie, ashley.campsie@ch2m.com Rad Byerly, hrbyerly@gmail.com Douglas Lempke, douglas.lempke@state.co.us TheresaMartin, theresa.martin@state.co.us North Front Range Metropolitan Planning Organization Suzette Mallette, smallette@nfrmpo.org
Regional Air Quality Council Kenneth Lloyd, klloyd@raqc.org

Orf& Orf, P.c.,law@orfco.net TedOrf DiannaL. Orf for ColoradoMining Association

Colorado Petroleum Association Stan Dempsey, Jr. stan@coloradopetroleumassociation.org Denver Regional Council ofGovernments Steve Cook, scook@drcog.org AirPollution Control Division Mike Silverstein, mike.silverstein@state.co.us Kirsten King, kirsten.king@state.co.us

Office ofthe Attorney General Jerry Goad,jerry.goad@state.co.us WilliamAllison, william.allison@state.co.us Thomas Roan, tom.roan@state.co.us Richard L. Griffith, ricklgrif@aol.com for Colorado Ethanol Group, including: ERAS, Inc.; Pacific Ethanol, Inc.; Sterling Ethanol LLC; and YumaEthanolLLC Fulbright & Jaworski LLP Kenneth A. Wonstolen, kwonstolen@fulbright.com Benjamin Vetter, bvetter@fulbright.com for Colorado Oil & Gas Association Meg Collins, meg.collins@coga.org Carver SchwarzMcNab & Bailey, LLC Jeffrey W. Schwarz,jschwarz@cksmb.com for DCPMidstream, LP Daniel J. Schnee, daniel.schnee@elpaso.com for EI Paso WesternPipelines consisting of: Colorado Interstate Gas Company; EI Paso Natural Gas Company; Wyoming Interstate Company, Ltd.; Cheyenne Plains Gas Pipeline Company, L.L.c.; and Mojave Pipeline Company; who are all subsidiaries of: TheEI Paso CorporationHolme Roberts & Owen LLP Colin G. Harris, colin.harris@hro.com for EnCana Oil & Gas (USA) Inc. DianeM. Blieszner, diane.blieszner@EnCana.com Hale Friesen, LLP Allan L. Hale, ahale@halefriesen.com AmandaA. Bradley, abradley@halefriesen.com Matthew W. Spengler, mspengler@halefriesen.com for Environmental Systems Products, Inc.

Faegre & Benson, LLP Linda L. Rockwood, lrockwood@faegre.com Eric J. Triplett, etriplett@faegre.com for Public Service Company ofColorado d/b/a Xcel Energy Lauren C. Buehler, lauren.c.buehler@xcelenergy.com WildEarth Guardians Jeremy Nichols, jnichols@wildearthguardians.org Environmental Defense Fund, Rocky Mountain Office Kevin Lynch, klynch@edf.org

BoulderCounty Public Health Pamela H. Milmoe, pmilmoe@bouldercounty.org Denver Environmental Health GreggThomas, gregg.thomas@denvergov.org SabrinaM. Williams, sabrina.williams@denvergov.org for Local Government Coalition representing: Denver Environmental Health; BoulderCounty Public Health; City ofAspen; and City ofBoulder SuncorEnergy (U.S.A.) Inc. Michael E. Korenblat, mkorenblat@suncor.com Jay Christopher,jchristopher@suncor.com

sfChristine M. Thompson



### -2­

## RECEIVED BEFORETHEAIR QUALITY CONTROLCOMISSION STATE OF COLORADO

### ~OV 

## 2 j 

## 2008 AIR QUALITY -----------------------------.......;;:COlQaQlmfll(l

..COMMISSOl WILDEARTH GUARDIANS' RESPONSEIN OPPOSITION TO THEAIR POLLUTION CONTROLDMSION'S MOTION TO BIFuRcATETHE INTERSTATE TRANSPORT SIPREVISION
INRE: PROPOSED REVISIONS TO AMBIENTAIR QUALITY STANDARDS REGULATION, REGULATION NUMBERS 3, 7, AND 11 FORTHEDENVER METROPOLITANAND NORTHFRONTRANGEAREA OZONEACTION PLAN

The Colorado Department ofPublic Health andEnvironment, Air Pollution Control Division ("Division"), by and through the Colorado Office ofAttorney General, has moved the Commission to bifurcate these proceedingsby (I) separating the Interstate Air Pollutant Transport component ofthe Colorado SIP ("Transport SIP") from the DenverlNorth Front Range Ozone component ofthe SIP and (2) considering the Transport SIP in a separate hearing during the Commission's December meeting. WildEarth Guardians opposes the Division's Motion to Bifurcate. As an initial matter, we so no reason that the current proposalbefore the Commission needs to be bifurcated for purposes ofadministrative convenience. In its motion, the Divisionhas asked the Commission to hold two separate hearings on the bifurcated SIP components at the very same Decembermeeting. In essence, this means that the parties will be required to produce the very same witnesses, and engage in examination andcross-examination of these witnesses, twice. This makes little sense from the standpoint ofefficiency. Moreover, it undermines the hearingwithregards to ensuring adequate fact-finding and public participation. Inreality, the two elements ofthe proposed Colorado SIP raise very similar questions for the Commission to consider, 

### e.g., whether the Divisionhas adequately modeled sources ofVOCs and NOx in the DenverlNorth Front Rangeboth to assure timely attainment ofthe ozone NAAQS in the region and to assure that these very same sources are not contributing to violations ofNAAQS or interfering with NAAQS attainment in downwind states. The Commission and parties to the hearing shouldbe given the opportunity to examine these related issues within the same hearing and at the same time. Second, the proposed bifurcation may result in the submission ofa SIP that violates federal law. Section llO(a)(2) ofthe federal Clean Air Act ("CAA"), 42 U.S.c. § 741O(a)(2), states in relevant part that:Eachimplementationplan submitted by a State under this chapter shall be adopted by the State after reasonable notice and public hearing. Each such plan shall­ (A) included enforceable emission limitations and other control measures ... [and] (C) include a program for the enforcement [ofsuch] measures ... to assure that national ambient air quality standards are achieved

... [and] (D) contain adequate provisions

­ (i) prohibiting, consistent with the provisions ofthis subchapter, any source orother type ofemissions activity within the State from emitting any airpollutant in amounts which will­

(I) contribute significantly to nonattainment in, or interfere withmaintenance by, any otherState with respect to any suchnational primary or secondary ambient air quality standard, or (II) interfere with measures required to be included in the applicable implementation planfor any other State under part C ofthis subchapter to prevent significant deterioration ofair quality orto protect visibility

... WEG believes that these provision ofthe federal CAA require that the State submit a singleproposed SIPrevision to the Federal EnvironmentalProtectionAgency ("EPA") that can ensure both future attainment ofthe national ambient air quality standard for ozone and that emission sources located within the DenverlNorthFront Range attainment air are not contributing to violations ofNAAQS or interfering with NAAQS attainment in downwind states. A submission to EPA ofonly one ofthese required SIP elements wouldbe incomplete, and the SIPproposal could notbe timely consideredbyEPA under theprovisions ofthe court-approved settlement agreement in Rocky Mountain Clean AirAction v. EPA, Civ. No. 07-1012 (D.C. Cir. 2006). See42 U.S.c. § 741O(K)(1); 40 C.F.R. Part 5 1,.App. V. Bifurcation ofthe proposed SIP revision is particularlyproblematic forpurposes of compliance with the federal CAA because it can potentially lead to the approval bythe State ofonly one ofthe two proposed elements ofthe SIP. This mayoccur, for instance, because the Commission chooses to adopt only one ofthe elements in Decembereither 2because oftime constraints at hearing orbecause the Division has not demonstrated that one ofthe elements is adequate under state orfederal law. Similarly, even ifboth elements are adopted bythe Commission, the Colorado legislature could choose to exercise its authority pursuant to state law to disapprove eitherthe Ozone SIP or Transport SIPs alone. In either case, the granting ofthe motion to bifurcatepotentially jeopardizes the timely approval ofthe proposed SIP by EPA because the state will notbe able to submit a complete SIP revision in compliance with Section 110 ofthe CAA. Finally, in its motion the Division suggests that the motivation for requesting bifurcation stems from acomment from EPA that the "Transport SIP has deficiencies

... and shouldbe separated from the Ozone SIP." While it may be true that, as it stands, the transport component ofthe SIP has legal deficiencies, separatingit from the Ozone SIP will not, for reasons stated above, ensure compliance with the CAA. More importantly, the EPA has statutory tools available to it to address a proposed SIP in which one or more elements are deficient. Specifically, Section 11O(k)(3) provides the EPA authority to issue a full orpartial approval (and disapproval) ofaSIP submission. In otherwords, there is no reason for the State tojeopardize compliancewith the CAA merelybecause one portion ofthe proposed SIP revisionmay not ultimately be approvable. EPA has sufficient legal authority to address that concern whenthe time comes for its evaluation of the SIP. In conclusion, for the foregoingreasons WildEarth Guardians requests that the Commission deny the Division's Motionto Bifurcate. Respectfully submitted this 21 st day ofNovember2008.

AND Michael R. Harris Asst. Professor ofLaw 

### &Director ENVIRONMENTAL LAW CLINIC UNIVERSITY OF DENVER STURM COLLEGE OFLAW

3

# EPA Comments

No Comments

# Public Comments



# No Comments

# Adopted Statement ofBasis, Specific Statutory Authority and PurposeStatementofBasis, Specific StatutoryAuthority and Purpose

THIS STATEMENT OF BASIS, SPECIFIC STATUTORY AUTHORITY AND**~URPOSE** SUPPORTS REVISIONS TO COLORADO'S IMPLEMENTATION PLAN REGARDING THE INTERSTATE TRANSPORT OF AIR POLLUTANTS (HEREINAFTER "INTERSTATETRANSPORT SIP"). THESE REVISIONS APPLY TO COLORADO'S STATE IMPLEMENTATION PLAN ONLY AND DO NOTREVISE ANY REGULATION. THEREFORE, THIS STATEMENT IS NOT REQUIRED BY THE ADMINISTRATIVE PROCEDURES ACT. NEVERTHELESS, THE COMMISSION OFFERS THIS STATEMENT TO FURTHER THE UNDERLYING OBJECTIVES OF THE APA AND THE COLORADO AIRPOLLUTION PREVENTION AND CONTROL ACT.
BASIS
THEAIRQUALITY CONTROL COMMISSION HAS ADOPTED REVISIONS TO THE INTERSTATE TRANSPORT SIP TO ADDRESS COMMENTS FROM THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (EPA) FINDING THE SIP DEFICIENT.
IN FEBRUARY OF 2007 THE COMMISSION ADOPTED AN INTERSTATE TRANSPORT SIP FOR OZONE AND PM2.5. THIS SIP WAS TRANSMITTED TO EPA IN JUNE OF 2008. SINCETHAT SIP PRECEDED THE 2007 OZONE SEASON, IT DID NOT REFLECT THE MONITORING RESULTS FROM THAT PERIOD, INCLUDING THE VIOLATION OF THE 1997 GROUND-LEVEL OZONENATIONAL AMBIENT AIR QUALITY STANDARDS (NAAQS) AND EPA's SUBSEQUENT DESIGNATION OF NONATTAINMENT FOR THE DENVER METRO AREA AND NORTH FRONT RANGE (DMAINFR). EPA OFFERED INFORMAL COMMENTS ON THE INTERSTATE TRANSPORT SIP, OPINING ON THIS AND OTHER PERCEIVED DEFICIENCIES. IN RESPONSE, THE COMMISSION ADOPTED THE FOREGOING REVISIONS TO ADDRESS DEFICIENCIES PERTAINING TO OZONE.
STATUTORY AUTHORITY
THE STATUTORY AUTHORITY FOR THESE REVISIONS IS SET FORTH IN § 25-7-105(1), C.R.S. OF THE COLORADO AIR POLLUTION PREVENTION AND CONTROLACT ("ACT"), WHICH AUTHORIZES THE COMMISSION TO ADOPT A STATE IMPLEMENTATION PLAN THAT MEETS ALL REQUIREMENTS OF THE CLEAN AIR ACT.
PURPOSE
THE PURPOSE OF THIS INTERSTATE TRANSPORT SIP REVISION IS TO ADDRESS EPA COMMENTS THAT THE SIP DOES NOT ADEQUATELY ADDRESS ANY ADVERSE IMPACTS THE DMAINFR NONATTAINMENTAREA MAY HAVE ON OTHER STATES' COMPLIANCE WITH THE OZONENAAQS. PURSUANT TO 42 U.S.c. § 7410(A)(2)(D)(I), COLORADO'S INTERSTATE TRANSPORT SIP MUST DEMONSTRATE, AMONG OTHER THINGS, THAT COLORADO'S AIR POLLUTION SOURCES WILL NOT CONTRIBUTE SIGNIFICANTLY TO NONATTAINMENT, OR INTERFERE WITH MAINTENANCE BY, ANY OTHER STATE OF THE OZONENAAQS. THE COMMISSION HAS REVISED THE OZONE TRANSPORT SECTION OF THE INTERSTATE TRANSPORT SIP TO INCLUDE ANALYSIS, MONITORING AND MODELING INFORMATION DEMONSTRATING THAT COLORADO, INCLUDING THE DMAINFR NON-ATTAINMENT AREA, DOES NOT CONTRIBUTE SIGNIFICANTLY TO NONATTAINMENT OR INTERFERE WITH MAINTENANCE BY ANY OTHER STATE WITH RESPECT TO THE 0.08 PPM OZONENAAQS.IN A SEPARATE ACTION, THE COMMISSION HAS ADOPTED THE OZONE ATTAINMENT PLAN TO ADDRESS EPA'sNON-ATTAINMENT DESIGNATION OF THE DMA/NFR AREA. THE OZONE ATTAINMENT PLAN AND THE INTERSTATE TRANSPORTPLAN, TOGETHER, FORM THE BASIS FOR A CONCLUSION THATCOLORADO'S SIP SATISFIES CLEAN AIR ACT REQUIREMENTS PERTAINING TO GROUND-LEVEL OZONE.

# AdoptedLanguagebythe Commission

### State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(l) Interstate Transport Regarding the 1997 8-Hour Ozone Standard

December 9, 2008 Colorado Department of Public Health and Environment Air Pollution Control Division 4300 Cherry Creek Drive South Denver, Colorado 80246 

### Adopted by the Air Quality Control Commission December 12,2008Colorado Department ofPublic Health andEnvironment/ Air Pollution Control Division

j State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division


# Table ofContents 1. OZONE-SPECIFIC PROVISIONS TO MEETTHE REQUIREMENTS OFCAA 11O(A)(2)(D)(I)(I)­ IN:rERSTATE TRANSPORT 1 1.1. INTRODUCTION I 1.2. COLORADO OZONE MONITORINGNETWORK 2 1.3. OZONE MONITORINGNETWORK IN NEARBY STATES 7 1.4. OZONETRANSPORT CONCLUSIONS FROM THE DMAINFRPHOTOCHEMICAL MODELING 10 1.4.1. Emission Inventories and2006and2010Base Case II 1.4.2. Discussion 0/2010Base Case CAMx Modeling Results 15 1.5. DENVER METRO AREAlNORTH FRONT RANGE OZONE NONATTAINMENTAREA CONTRIBUTION TO DOWNWIND LOCATIONS 18 1.6. SECTION llO(A)(2)(D)(J)(I)

- OZONE TRANSPORT CONCLUSIONS 20 2. REFERENCES 22 

# List ofTables Table 1: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008) 

### .4 Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30,2008) 5 Table 3: 8-Hour Design Value Using the 3-Year (2006-2008) Average ofthe Fourth Maximum Ozone Concentration 6 Table 4: 2005-2007 3-Year Fourth HighestAverage Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming 7 Table 5. Base Case Inventories for 8-Hour Ozone DMAlNFRNAA Photochemical Modeling 14


# List of Figures Figure 1. Location ofFront Range Ozone Monitors 2**Fig~re** 2. Location ofStatewide Ozone Monitors 3 Figure 3: 8-Hour Ozone Nonattainment Areas 9 Figure 4. Nested 12/4 km modeling domains for the Denver CAMx air quality and SMOKE emissions modeling : 10 Figure 5. Projected 2010 8-hour ozone Design Values (DVF) 15 Figure 6. Rocky FlatsNorth source apportionment for 29 July including boundary conditions 16 Figure 7: Spatial extent ofthe 8-hour ozone concentrations that occurred between lOam and 6pm local time on June 27, 2002 through July 1, 2002 19

ii State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

iii State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment I Air Pollution Control Division



## 1. Ozone-Specific Provisions to Meet the Requirements of CAA 11O(a)(2)(D)(i)(I) - Interstate Transport 1.1. Introduction The purpose ofthis document is to provide a plan for the State ofColorado to meet the requirements ofthe Clean Air Act Section 110 (a)(2)(D)(i)(I) Interstate Transport requirements regarding the 0.08 parts per million (ppm) 8-Hour Ozone National Ambient Air Quality Standard (NAAQS). This addresses the applicable components of 110(a)(2)(D)(i)(I) demonstrating adequate provisions to prevent emissions from Colorado from interfering with attainment ormaintenance ofthe federal ozone NAAQS in any other state. This analysis does not address ozone transport for the revised 0.075 ppm 8-Hour Ozone NAAQS. This document replaces the section titled "Ozone-Specific Provisions" in the document "State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour Ozone and PM25

. NAAQS." Currently, the Denverarea is the only area in U.S. Environmental Protection Agency (EPA) Region VIII that is designated as nonattainment for the 8-hour ozoneNAAQS of 0.08 ppm. . In this report, relevant information from the DenverMetropolitan Area and North Front Range (DMAlNFR) 8-hour Ozone State ImplementationPlan (SIP) process, the Denver Early Action Compact (EAC)process, ambient ozone data for Colorado, ambient ozone data for nearby states from the EPA Air Quality System (AQS) database, andother information is usedto demonstrate that Colorado does not contribute significantly to nonattainment in, orinterfere with maintenance by, any other state with respect to the 0.08 ppm ozoneNAAQS.

1 State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section J10 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division


### 1.2. Colorado Ozone Monitoring Network The 2007/2008 ozone ambient air monitoring network in the Denver area and alongthe northern Front Range consists of 13 stations operated by the Colorado Air Pollution Control Division (APCD) and one station operated by the National Park Service (NPS) in Rocky MountainNational Park. There have been other stations that have operated in the past. The geographical distribution ofthe Front Range monitors is presented in Figure 1. As shown in Figure 1, the ozone monitors are primarily located in urbanized areas along the Front Range corridor. The monitors are located in areas where the highest ozone concentrations have beenmonitored historically and where elevated ozone is expected to occur. Highozone concentrations along the Front Range occurnear the areas with high emissions density and dense population. In addition, elevated ozone is observed along elevated terrain to the west ofthe DMAlNFRNonattainment Area. All ofthese monitors are designated by the U.S. Environmental ProtectionAgency as "equivalent" analyzers and follow all quality assurance requirements as specified in 40 CFR Part 58, Appendix A.

simla'" Ramah,,"#," .//" Figure 1. Location ofFront Range Ozone Monitors

2 State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division



### Figure 2 shows other ozone monitoring sites that existin Colorado for 2008. These are operated by either Colorado, the Southern Ute Tribe, or various Federal agencies. All of these sites use monitors that are designated as "equivalent" analyzers by the U.S. Environmental Protection Agency. As shown, most ofthe sites are in the southwest comer ofColorado, either within ornear the San Juan oil and gas development area.



# .­ " _0 (noftMllfl

### .,,"":~**V<"!:~'"** """" (,k..,' 

# J
w.-....(#} <?­ ., -,.**)'~:** ..**,,~**

Figure 2. Location ofStatewide Ozone Monitors 

### Table I, Table 2, and Table 3present the monitoring datafor the DMA/NFRNAA monitoring sites (including the NPS Rocky Mountain National Parkmonitoring site) as well as for other sites in Colorado. In Table 3, the fourth maximum 8-hour ozone concentrations along with the 3-year average ofthe fourth maximum concentrations at each site are presented. As shown in both Table I and Table 3, the Denver area is currently meeting the 8-hour and former I-hour ozone NAAQS for all sites, except for the 8-Hour NAAQS at Rocky Flats North with a design value of0.86 ppm.

3 State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(1)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division
Table I: 2008 I-Hour Ozone Monitored Concentration (updated through Sept. 30,2008)
AQS Number Site Name 1st Max I-Hour (ppm) Date 1stMax I-Hour 2nd Max I-Hour (ppm) Date 2nd Max I-Hour 3rd Max I-Hour (ppm) Date 3rd Max I-Hour 4th Max I-Hour (ppm) Date 4th Max I-Hour 08-001-3001 Welby 0.100 08/29 0.095 08/05 0.092 07/10 0.089 06/20 08-005-0002 * Highland 0.065 04/04 0.064 04/08 0.064 04/18 0.062 04/19 08-013-0011 S. Boulder Creek 0.089 07/10 0.089 07/25 0.086 07116 0.085 05/31 08-031-0014 Carriage 0.094 08/05 0.090 08/29 0.089 07/10 0.085 06/20**08~031-0025 Denver

- Animal Shelter 0.100 07/10 0.098 08/05 0.087 06/20 0.087 08/24 08-035-0004 Chatfield State Park 0.101 07/10 0.098 06/20 0.095 08/29 0.092 08/24 08-041-0013 Colo. Spgs.

- Academy 0.085 OS/24 0.083 07/10 0.082 08/06 0.080 07/18 08-041-0016 Manitou Springs 0.087 OS/24 0.085 08/06 0.083 07/10 0.083 07/11 08-045-0012 **  Rifle

- Health 0.081 07/09 0.080 07/10 0.075 08/19 0.074 07/11 08-059-0002 Arvada 0.093 08/05 0.093 08/29 0.092 07/10 0.088 07/25 08-059-0005 Welch 0.102 07/10 0.090 06/20 0.088 08/05 0.088 08/29 08-059-0006 Rocky Flats - N 0.088 07/10 0.088 07/18 0.088 08/29 0.087 07/02 08-059-0011 NREL 0.097 08/29 0.093 07/10 0.092 08/05 0.092 08/24 08-067-7001 *** So. UteIgnacio 0.076 06/04 0.075
----05/31 0.073 05/03 0.072 05/3 08-067-7003 *** So. UteBondad 0.080 06/04 0.078 05/31 0.077 OS/27 0.071 04/21 08-067-???? USFS

- Shamrock 0.081 06/04 0.079 06/10 0.077 02/29 0.077 05/30 08-069-0007 Rocky Mountain Nat'l Park 0.092 07/09 0.090 07/31 0.090 08/28 0.085 OS/22 08-069-0011 Ft. Collins

- West 0.093 08/19 0.092 07/09 0.092 07/18 0.088 07124 08-069-1004 Ft. Collins

- CSU 0.082 08/19 0.080 07/09 0.079 08/30 0.078 07124 08-077-0020 

### ** Palisade

- Water 0.081 07/09 0.079 07/10 0.075 07/08 0.074 07/05 08-083-0006 ** Cortez 0.078 07/23 0.074 07113 0.072 08/05 0.071 07/25 08-083-0101 Mesa Verde Nat'l Park 0.075 05/01 0.075 06/04 0.074 05/31 0.072 04/30 08-123-0009 Greeley

- Weld Tower 0.094 08/20 0.092 07/24 0.089 08/01 0.087 08/04 NOTES: 

### *Highland site shut down on 4/21/08 for approx. 6-months. 

### ** Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Water commenced on 5/30/08 and Cortezcommenced on 6/17/08. 

### *** Southern Ute sites dataonlythru 6/30/08.

4 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ AirPollution Control Division
Table 2: 2008 8-Hour Ozone Monitored Concentration (updated through Sept. 30, 2008)
AQS Number Site Name 1st Max 8-Hour (ppm) Date 1st Max 8-Hour 2nd Max 8-Hour (ppm) Date 2nd Max 8-Hour 3rd Max 8-Hour (ppm) Date 3rd Max 8-Hour 4th Max 8-Hour (ppm) Date 4th Max 8-Hour 08-001-3001 Welby 0.085 07/10 0.083 08/29 0.077 07/18 0.076 06/20 08-005-0002 • Highland 0.062 04/04 0.060 04/08 0.060 04/18 0.059 04/05 08-013-00II S. Boulder Creek 0.080 07/10 0.076 05/31 0.076 07/09 0.076 07/18 08-031-0014 Carriage 0.081 07/10 0.075 08/29 0.073 06/20 0.072 07/26 08-031-0025 .. Denver

- Animal Shelter 0.086 07/10 0.072 08/29 0.071 07/13 0.070 07/26 08-035-0004 Chatfield State Park 0.090 07/10 0.082 06/30 0.080 06/20 0.080 06/27 08-041-0013 Colo. Spgs.

- Academy 0.078 OS/24 0.077 07/10 0.073 08/06 0.070 07/18 08-041-0016 Manitou Springs 0.080 OS/24 0.076 07/10 0.074 07/11 0.072 07/31 08-045-0012 *II< Rifle

- Health 0.076 07/09 0.076 07/10 0.069 08/19 0.066 07/13 08-059-0002 Arvada 0.081 08/29 0.080 07/10 0.077 06/20 0.074 08/05 08-059-0005 Welch 0.095 07/10 0.079 06/20 0.077 07/18 0.073 08/19 08-059-0006 Rocky Flats - N 0.083 07/10 0.080 07/18 0.079 05/31 0.079 08/29 08-059-00II NREL 0.085 07/10 0.085 08/29 0.077 06/20 0.076 06/02 08-067-700I ... So. UteIgnacio 0.069 06/04 0.067 06/10 0.066 05/10 0.066 06/13 08-067-7003 

### ..*So. UteBondad 0.073 06/04 0.067 OS/27 0.067 05/31 0.067 06/05 08-067-???? USFS

- Shamrock 0.074 06/04 0.073 06/10 0.071 06/13 0.069 05/30 08-069-0007 Rocky Mountain Nat'l Park 0.081 07/09 0.077 OS/25 0.077 07/31 0.076 05/31 08-069-00II Ft. Collins

- West 0.081 07/18 0.079 07/09 0.078 OS/25 0.076 07/24 08-069-1004 Ft. Collins

- CSU 0.070 OS/25 0.070 07/09 0.068 07/18 0.066 05/31 08-077-0020 

### ** Palisade

- Water 0.077 07/09 0.075 07/10 0.070 05/31 0.070 07/29 08-083-0006 

### ** Cortez 0.067 08/02 0.066 07/23 0.065 08/07 0.064 08/05 08-083-0101 Mesa Verde Nat'l Park 0.071 06/04 0.070 04/30 0.069 04/21 0.069 06/10 08-123-0009 Greeley

- Weld Tower 0.077 07/24 0.076 08/20 0.075 07/26 0.073 08/01 NOTES: 

### *Highland site shut down on 4/21/08 for approx. 6-months. 

### ** Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Watercommenced on 5/30/08 and Cortez commenced on 6/17/08. 

### *** Southern Ute sites dataonly thru 6/30/08.

5 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(iXI)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

Table 3: 8-Hour Design Value Usingthe 3-Year (2006-2008) Average ofthe Fourth Maximum Ozone Concentration

.

Site Name AQS# 2006 

## 7 Maximum

8-Hour Average Value (ppm) 2007 

## 7 Maximum

8-Hour Average Value (ppm) 2008 

## 7 Maximum

8-Hour Average Value (ppm) Design Value (2006

- 2008) 3-Year Average 4th Maximum Value (ppm) Welby 08-001-300I 0.069 0.070 0.076 0.071

... Highland 08-005-0002 0.081 0.075 0.059 0.071 S. Boulder Creek 08-013-0011 0.082 0.085 0.076 0.081 Carriage 08-03 1-0014 0.072 0.076 0.072 0.073

..Denver

- Animal Shelter 08-03 1-0025


### --­ 

## --­ 0.070


### --- Chatfield State Park 08-035-0004 0.086 0.082 0.080 0.082 USAF Academy 08-041-0013 0.072 0.072 0.070 0.071 Manitou Springs 08-041-0016 0.076 0.072 0.072 0.073

...... Rifle

- Health 08-045-0012 

### --­ 

## --­ 0.066


### --­ Arvada 08-059-0002 0.082 0.079 0.074 0.078 Welch 08-059-0005 0.081 0.080 0.073 0.078 Rocky Flats

- North 08-059-0006 0.090 0.090 0.079 0.086 NREL 08-059-00II 0.083 0.085 0.076 0.081

..... So. Ute

- Ignacio 08-067-7001


### --­ 

## --­ 0.066


### --­

..* So. Ute

- Bondad 08-067-7003 0.063 0.071 0.067 0.067 USFS

- Shamrock 08-067-71?? 0.074 0.069 0.069 0.070 Rocky Mountain Nat'l Park 08-069-0007 0.076 0.078 0.076 0.076 Fort Collins

- West 08-069-00II 0.087 0.085 0.076 0.082 Fort Collins

- CSU 08-069-1004 0.078 0.069 0.066 0.071 

### ** Palisade

- Water 08-077-0020


### --­ --­ 0.070


### --­ ** Cortez 08-083-0006


### --­ --­ 0.064


### --­ Mesa Verde Nat'IPark 08-083-0I0 I 0.074 0.070 0.069 0.071 Greeley

- Weld Tower 08-123-0009 0.082 0.074 0.073 0.076 NOTES: 

### *Highland site shut down on 4/21108 for approx. 6-months. 

### ** Denver

- Animal Shelter site commenced on 4/22/08, Rifle

- Health commenced on 6/20/08, Palisade

- Water commenced on 5/30/08 and Cortez commenced on 6/17/08. 

### *** Southern Ute sites data onlythru 6/30/08. Ignacio data invalid for 0112005 to 08/2007.

6 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment IAir Pollution Control Division 

### 1.3. Ozone Monitoring Network in Nearby States Table 4 present 8-hour ozone monitoring data from the surrounding states ofNebraska, Kansas, New Mexico, Wyoming, and Utah. Table 4 and showthat none ofthemonitors in surrounding states exceed the 8-hour ozone standard except for Davis County Utah. Therefore, to the extent that the network is representative ofall areas, it can be concluded thatthe DMAlNFR sources do not significantly contribute to the 8-hourozone standard violations at these down wind locations or evenfurther downwind. In addition, Colorado does not significantly contribute to violations upwind including Davis County Utah. Utah's 8-hourproposed 8-hour maintenance plan for the 1997 8-hour ozone standard does not suggestthat Colorado interferes with the maintenance ofthe standard in Davis County Utah. Table 4: 2005-2007 3-Year Fourth HighestAverage Monitoring Concentrationsfrom Kansas, Nebraska, New Mexico, Utah and Wyoming

SiteID State County EPA Ree:ion 2005 8-hr Ozone 4th Max

(ppm) 2006 8-hr Ozone 4th Max

(ppm) 2007 8-hrOzone

4th Max

(ppm) 3-yr Avg. of 4th MaxI

(ppm) 20-045-0004 KS Douglas 7 0.073 0.081 End 2007 N/A 20-091-0010 KS Johnson 7 0.081 0.076 0.071 0.076 20-103-0003 KS Leavenworth 7 0.077 0.074 0.080 0.077 20-107-0002 KS Linn 7 0.075 0.079 0.070 0.074 20-173-0001 KS Sedgwick 7 0.065 0.065 0.059 0.063 20-173-0010 KS Sedgwick 7 0.074 0.073 0.060 0.069 20-191-0002 KS Sumner 7 0.078 0.080 0.070 0.076 20-195-0001 KS Trego 7 0.071 0.076 0.068 0.071 20-209-0021 KS Wyandotte 7 0.079 0.081 0.073 0.077 31-055-0028 NE Douglas 7 0.069 0.072 0.066 0.069 31-055-0032 NE Douglas 7 0.067 0.066 0.056 0.063 31-055-0035 NE Douglas 7 0.070 0.067 0.061 0.066 31-109-0016 NE Lancaster 7 0.056 0.056 0.054 0.055 35-001-0019 NM Bernalillo 6 0.073 0.073 0.070 0.072 35-001-0023 NM Bernalillo 6 0.072 0.073 0.069 0.071 35-001-0024 NM Bernalillo 6 0.074 0.074 0.068 0.072 35-001-0027 NM Bernalillo 6 0.073 0.072 0.071 0.072 35-001-0029 NM Bernalillo 6 0.071 0.070 0.067 0.069 35-001-1012 NM Bernalillo 6 0.077 0.047 0.074 0.066 35-001-1013 NM Bernalillo 6 0.077 0.071 0.071 0.073 35-001-1014 NM Bernalillo 6 0.072 0.072 0.064 0.069 35-013-0008 NM Dona Ana 6 0.070 0.072 0.068 0.070 35-013-0017 NM Dona Ana 6 0.070 0.073 0.070 0.071 35-013-0020 NM Dona Ana 6 0.072 0.072 0.068 0.070 35-013-0021 NM DonaAna 6 0.076 0.080 0.076 0.077 35-013-0022 NM DonaAna 6 0.070 0.073 0.073 0.072 35-013-0023 NM Dona Ana 6 0.066 0.070 0.062 0.066

7 State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(l)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division
Table 4 (continued) 2005-2007 3-Year Fourth Highest Average Monitoring Concentrations from Kansas, Nebraska, New Mexico, Utah and Wyoming

Site ill State County EPA Reeion 2005 8-hr Ozone 4th Max

(ppm) 2006 8-hr Ozone 4th Max

(ppm) 2007 8-hrOzone

4th Max

(ppm) 3-yr Avg. of 4th Max

(ppm) 35-015-1005 NM Eddy 6 0.067 0.076 0.066 0.069 35-017-1003 NM Grant 6 0.071 0.067 0.062 0.066 35-025-0008 NM Lea 6 0.074 0.075 0.064 0.071 35-029-0003 NM Luna 6 Start 2006 0.053 0.062 N/A 35-043-1001 NM Sandoval 6 0.069 0.064 0.063 0.065 35-043-1003 NM Sandoval 6 0.075 0.074 0.071 0.073 35-043-9004 NM Sandoval .6 0.076 0.072 0.067 0.071 35-045-0009 NM San Juan 6 0.075 0.063 0.069 0.069 35-045-0018 NM San Juan 6 Start 2006 0.079 0.079 N/A 35-045-1005 NM San Juan 6 0.072 0.071 0.073 0.072 49-003-0003 UT Box Elder 8 0.079 0.078 0.077 0.078 49-003-7001 UT BoxElder 8 0.075 0.076 0.078 0.076 49-005-0004 UT Cache 8 0.069 0.073 0.074 0.072 49-011-0004 UT Davis 8 0.092 0.082 0.082 0.085 49-035-0003 UT Salt Lake 8 0.083 0.084 0.082 0.083 49-035-2004 UT Salt Lake 8 0.086 0.082 0.082 0.083 49-035-3006 UT Salt Lake 8 0.082 0.082 0.079 0.081 49-035-3007 UT Salt Lake 8 0.085 0.080 0.080 0.081 49-035-3008 UT Salt Lake 8 0.080 0.082 0.079 0.080 49-037-0101 UT. San Juan 8 0.069 0.070 0.072 0.070 49-045-0003 UT Tooele 8 0.080 0.079 0.076 0.078 49-049-0002 UT Utah 8 0.078 0.074 0.075 0.075 49-049-5008 UT Utah 8 0.080 0.077 0.078 0.078 49-049-5010 UT Utah 8 0.080 0.079 0.077 0.078 49-053-0130 UT Washington 8 0.091 0.072 0.071 0.078 49-057-0007 UT Weber 8 0.081 0.083 0.080 0.081 49-057-1003 UT Weber 8 0.084 0.083 0.082 0.083 56-005-0123 WY Campbell 8 0.063 0.072 0.072 0.069 56-005-0456 WY Campbell 8 0.063 0.065 0.072 0.066 56-035-0098 WY Sublette 8 0.075 0.069 0.068 0.070 56-035-0099 WY Sublette 8 0.079 0.072 0.067 0.072 56-035-0100 WY Sublette 8 0.066 0.074 0.066 0.068 56-037-0200 WY Sweetwater 8 Start 2006 0.067 0.064 N/A 56-039-1011 WY Teton 8 0.060 0.069 0.065 0.064 Figure 3 presents a map ofall the U.S. nonattainment areas for the 1997 8-hourozone standard

.. Since the surrounding states ofKansas, Nebraska, Wyoming, Utah, and New Mexico do not have violations the 8-hour NAAQS for ozone, it canbe reasonably concluded that Colorado sources do not significantly affectthe ozone nonattainment areas 8 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

even further downwind such as Dallas-Forth Worth and 81. Louis nonattainment areas. In addition, it is unlikely that Colorado would significantly affect nonattainment areas that are typically "upwind" such as Las Vegas and Phoenix. However, it is recognizedthat, under the types ofsynoptic scale meteorological regimes that occur during some regional ozone episodes, simple terms like "upwind" and "downwind" maynot be applicable. Thus, photochemical modeling is neededto study the distribution ofozone under a variety of meteorological regimes.

Nonattainment and Maintenance Areas in the U. S. a-hour Ozone Standard



# ( \ .: :' I-**~-** 

# \ L{\\:.---..--­ j

### ~~' ..!' 

# -···-r---- ------!

-- " - l----­**\-~-~** ! I II

, " ,**-~--~**

# ""'"'·""--L:.---,\~---,-j • I I. 

# Y -) (' " \ L' \ ----,"-,

..--,.;\

, J- '. 'I '

• Nonattainmen'A,ea. (263 enti

..

# ,,,"::'~;"\,**(_~~(C-'V'\**

# \ i-' '-. Nonattainment Areas (30 partial counties) \ '\ ' 

# mrJ Maintenance Areas (141 entire or partial counties)""'

__ \'\.j



### . . Partial counties, those with part ofthe county designated nonattainment and art attainment, are shown as fuR counties on the rna . Figure 3: 8-HourOzone NonattainmentAreas

9 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour Ozone--- Colorado Department ofPublic Health and Environment/ Air Pollution Control Division



### 1.4. Ozone Transport Conclusions from the DMAlNFR Photochemical Modeling The DMAlNFRphotochemical model domain was defined ona nested 36-kilometer (km), 12 km, and a 4 km nested-grid structure. This structure was utilized in conjunction with the Comprehensive Air-quality Model with extensions (CAMx) air quality model (ENVIRON, 2008). CAMx, SMOKE (Coats, 1996), and CONCEPT MS (Loomis et aI., 2005) air quality and emissions modeling was performed for the June-July 2006 period. Nested 36/12/4 km modeling domains were used in the Denver 8-hour ozone modeling study. The CAMx model was first applied to the 36km continental U.S. domain using boundary conditions (BCs) from a global climate air quality model. The CAMx 2006 and 2010 base case modeling results from the 36 km continental U.S. domain simulation were then processed to generate BCs for the CAMx 12/4 km domain (Figure 4) for the 2006 12/4 km base case and 2010 12/4 km base case and sensitivity simulatioris. The CAMx simulations for the 12/4 km domains wererun using two-way interactive grid nesting (i.e., pollutants can flow back and forth between the 12 km and 4 km domains to account for recirculation). The larger 36km domain was selected to address the impact ofboundary condition uncertainties for the Front Range area ofColorado, as APCD was concerned there may be transport from Southern California and Texas. The 12 km grid resolution domain essentially covers the central Rocky Mountain States orportions thereof(i.e., Arizona, Colorado, New Mexico, Utah and Wyoming.) The 4 km nested-grid covers most ofthe state ofColorado.
480 , / :I ..••

.L.

.._.._ ; ! 360...:**~----.** I 1-
- ----.-.- _ .. 

## -----'1I

- 240­ 

### t .,---£::------r--,**----~** 

# " -1 :... 120 , I
, I I 

### \-.-­ '. 

### -'._

.. -- .,---""? 0

I 

## \ -120 , I , \ 

### / i r---

# --

...

### --- 

### I
, ·240 I, i II --- .t---­ CAMx4km I "**=~--=-=----=-=--** I 

# r'/ -360 \ \, , I \, \ 

# I
" J -480 "...' H I r) t, !: 1/ i CAMx 12km -600 ,i I" "

.. 'I' ":. "I -1680-1560-1440-1320-1200-1080 ·960 -840 -720 -600 -480 -360 -240 -120 o 120 240 

## \

Figure 4. Nested 12/4 km modelingdomains for the DenverCAMx air quality and SMOKE emissions modeling.

10 State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division



### 1.4.1. Emission Inventories and 2006 and 2010 Base Case The photochemical modeling for the "2010base case" emissions scenario perfonned for the DMAlNFR Ozone SIP process demonstrates compliance in the FrontRange Region with the 8-hour 0.08 ppm ozoneNAAQS. Control measures in place in 2006 and assumed for 2010 include: 1. Federal tailpipe standards and regulations, including those for small engines and non-road mobile sources. Creditis taken for these federal requirements butthey are notpart ofthe Colorado SIP. The credits change from 2006 to 2010 as the United States Environmental ProtectionAgency (EPA) TierII and low sulfur gasoline standards become effective. 2. Air Quality Control Commission Regulation No. ll--coveringthe Automobile Inspection and Readjustment (A.LR.) program in place during the 2006 ozone season, which includes an enhanced Inspection/Maintenance (11M). 

### For2006, a maximum of 10% fleet coverage is assumed, and for 2010, a maximum of50% fleet coverage is assumed for the remote sensing clean screenprogram in the Denver metro area (DMA) based on Regulation No. 11. 3. Air Quality Control Commission Regulations No.3, No.6, No.7, and Common Provisions--covering gasoline station and industrial source control programs. The Common Provisions, Parts A and B ofRegulation No.3, and the volatile organic compounds (VOC) control requirements ofRegulation No.7 are already included in the approved SIP. Regulation No.6 and Part C ofRegulationNo.3 implement the federal standards ofperfonnance for new stationary sources and the federal operating permit program. This reference to Regulation No.6 and Part C of Regulation No.3 shall not be construed to mean thatthese regulations are included in the SIP. 4. Since 2004, gasoline sold in the Denvermetro area during the summerReid Vapor Pressure (RVP) ozone season (June 1to September 15) has been subjectto a national RVP limit of7.8 poundsper square inch (psi) to reduce fuel volatility. For ethanol-blended fuels, the RVP limit is 8.8 psi due to the federal 1.0 psi RVP waiver for ethanol. Since 1991, gasoline sold in the Larimer and Weld area during the summerozone season (June 1to September 15) has been subject to a national RVP limit of9.0psi to reduce fuel volatility. Forethanol-blended fuels, the RVP limit is 10.0 psi due to the federal 1.0 psi RVP waiver for ethanol. For 2006, the RVP ofgasoline for the Denver metropolitan portion of nonattainment areawas determined by survey to be at 8.2 psi, with an ethanol market share of60%, and for the Larimer and Weld portion ofthe nonattainment area the RVP was determined to be 8.4 psi with the same ethanol share of60%. For purposes ofthe base case 2010 mobile source inventory, the RVP ofthe base II State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section JI

### o(a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ AirPollution Control Division 

### gasoline is assumed to be 7.8 psi for the Denver metropolitanportion of nonattainment area, with an ethanol market share of85%, and for the Larimer and Weld portion ofthe nonattainment area the RVP was assumed to be 9.0 psi with an ethanol share of25%. 5. The EPA approved the EAC Ozone Action Plan (OAP) onAugust 19, 2005. The OAP included an amendment to Regulation No.7 requiring the reduction offlash emissions ofvolatile organic compounds from condensate collection, storage, processing and handling operations by May 1, 2005. This initial rule required the installation ofair pollution control technology to achieve a system-wide 47.5% reduction from uncontrolled emissions ofvolatile organic compounds from new and existing oil and gas exploration and production operations located within the 8-hour ozone nonattainment area designated by EPA for operators with total emissions greaterthan 30 tons per year. The 2006 base case estimate was developed from actual reported emissions based onthe system-wide 47.5% reductionrequirement. 6. In February 13,2008,the EPA approved revisions to Regulation No.7to require the system-wide reduction ofcondensate tank flash VOC emissions of75% for the 2007 ozone seasonby May 1,2007 and 78% reduction for the 2012 ozone season, with technology that achieves a 95% reduction in VOC emissions. The 2010 base case emissions estimate assumes the 75% system-wide reductionrequirement. 7. The effect ofEPA final locomotive Tier 3 standards were considered and included, where appropriate, in the 2010 area source estimates. Tier4 locomotive standards do not go into effect until 2015 and therefore were not included in the 2010 inventories. All ofthe inventories in this 8-hour Ozone Attainment SIP were developed using EPA approved emissions modeling methods, including EPA's MOBILE6 model and local VMT datafor on-road mobile source emissions, EPA's non-road model and local demographic information for area and off-road sources, and reported actual emissions for point sources. Estimates for future emissions are based onthe above-mentioned tools and the EPA's Economic Growth and Analysis System (EGAS) model for estimating future point sources activity, VMT growth for on-road mobile sources, and 2010 and 2012 demographic data for off-road and area sources. The technical support document contains detailed information onmodel assumptions and parameters for each source category. Highway mobile source emissions are from the ENVIRON Consolidated Community Emissions ProcessingTool (CONCEPT) model inventory, which is based on DRCOG VMT data and MOBILE6 input dataprovided by APCD and expanded to the entireNAA based on VMT from the North Front Range Transportation and Air Quality Planning Council and CDOT. Non-road source emissions are from the EPA Non-Road Model. This model includes the impact offuture controls on non-road engines, which is used in equipment such as lawn and garden equipment and construction equipment. Oil and gas source emissions are from 12 State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment I Air Pollution Control Division
the revised Independent Petroleum Association ofMountain States (lPAMS) inventory, and were projected to 20lOusing the methodology in the IPAMS projection methodology document. The IPAMS inventory was sponsored by the IPAMS and is Phase III ofa regional oil and gas emission inventory for the Inter-Mountain Westjointly with the Western Regional Air Partnership (WRAP). Non-oil and gas area source emissions (including heating, consumer solventuse, aircraft and railroads, etc.) are from the 2002 EPA National Emissions Inventory (NEI), grownto 2006 and 2010 by population growth from data from the State Demographer. Consumer solvent emission reductions based on 75% ofthe per-person reductions listed in the EPA May 30, 2007 Emission Reduction Credit Memo were appliedto the projected 2010 nonoil and gas area source inventory. A checkon the non-oil and gas area sources estimates comparing the recently available 2005 NEI emissions data is shown later in this document. An inventory completed in 2005 for Denver International Airport (DIA) was used for aircraft and airportnon-road source emissions from DIA for both 2006 and 2010. Non-oil and gas point source emissions were grownto 2010 by the EPA EGAS economic model, and by adding sources for which pennits have been issued. Emissions ofVOC and nitrogen oxides (NOx) from biogenic sources have been generated by the Model ofEmissions ofGases and Aerosols from Nature (MEGAN) Biogenic Emissions Model using land cover database ofbiomass type and density and hourly meteorology data. The National Center ofAtmospheric Research (NCAR) has produced a global database ofland use data, the MEGAN Driving Variable Database Version 1.2, for use with MEGAN. Surface temperatures are providedby the Mesoscale Meteorological Model (MM5) modeling. Summaries ofthe VOC and NOx base case inventories for the nonattainment area for 2006 and 2010 are presented in Table 5. Emissions ofNOx and VOCs are in tons per average episode day. Additional detail on the categories ofemissions can be found in the TSD. Wildfire emissions, though not included in tables, have been considered for the background ozone concentrations inthe modeling effort. Wildfire emissions canvary significantly on a day-to-day basis depending on conditions.

13 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health andEnvironment / Air Pollution Control Division

Table 5. Base Case Inventories for 8-Hour Ozone DMAlNFRNAA Photochemical Modeling (tons per average episode day) 2006 2010 Source Category NOx VOC NOx VOC Point Sources Electric Generation Units (EGU) 55.6 0.7 58.5 1.6 External Combustion Boilers 9.5 04 10.0 0.5 Industrial Processes 12.5 10.2 14.0 11.0 Petroleum and Solvent Evaporation 0.3 190 0.3 22.0 Other 3.1 1.8 3.6 2.0 Point Sources Subtotal 81.0 32.1 86.4 37.0 Oil & Gas Point & Area Sources Condensate Tanks 126.5 129.6 Other O&G Point Sources 22.6 6.8 23.6 8.6 Pneumatic Devices (Area Source) 248 31.1 Unpermitted Fugitives (Area Source) 162 204 Other Area Sources 17.1 10.8 22.5 13.7 O&G Point & Area Sources Subtotal 39.7 185.2 46.2 203.3 Area Sources Personal Care Products 7.1 7.0 Household Products 214 179 Automotive Aftermarket Products 11.9 13.0 Architectural Coatings 201 16.8 Aircraft 74 : 1.3 82 1.5 Railroad 12.8 : 0.5 13.8 0.6 Other CoatingslPesticides/Cooking/ Miscellaneous. 

# · 3.9 4.1 Area Source Subtotal 20.2 : 66.3 22.1 61.0 Non-Road Mobile Sources Agricultural Equipment 70: 0.9 6.3 : 07 Airport EqUipment 0.7 : 0.1 0.6 : 0.1 Commercial Equipment**53~** 62 5.1 : 7.0 Construction and Mining Equipment 35.7 : 55 31.2 : 4.5 Industrial Equipment 10.5 : 24 6.9 : 14 Lawn and Garden Equipment (Commercial) 9.4 : 35.9 8.9 

## ! 28.1 Lawn and Garden Equipment (Residential) 1.2 : 7.5 1.2 : 11.8 Boats/Recreational EquipmenUMiscellaneous 0.7 : 6.9 0.8 : 7.8 Non-Road Mobile Source Subtotal 70.5 : 65.3 

# · 165.5 : 129.7 165.5 : 129.7
376.8 : 478.6

53.0 : 694.0 

# · 429.8 : 1172.6 61.0 : 61.3

122.9 : 1092 122.9 : 109.2
338.5 : 471.8

53.0 : 694.0 391.5 : 1165.8 On-Road Mobile Sources On-Road Mobile (inclUding vehicle refueling) On-Road Mobile Subtotal Anthropogenic Total Bioaenic Total Anthropoaenic & Bioaenic Total


### 14 State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(I)
- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division

1.4.2. Discussion of2010 Base Case CAMx ModelingResults Currently, Colorado's highest emissions density is along the FrontRange. As shown in Figure 5 Photochemical Modeling done for the DMAINFR SIP process shows that the highest 2010 ozone design values along the foothills west ofDenver and Fort Collins. Ozone concentrations decrease rapidly to the east ofDenver. The maximum projected 20I0 base case 8-hour ozone Design Value of84 ppb occurs at both the Rocky FlatsNorth and Fort Collins West monitoring sites. As this value is 84 ppb or lower, the 2010 base case modeling results pass the EPA modeled attainment demonstration test. Although the EPA 8-hour ozone projection procedure is to truncate the final projected DVF for comparisons with the NAAQS, the projected 2010 base case future years design value is 84.9ppb (Morris, et aI, 2008a). White (unshaded) areas in Figure 5 have future design value ofless than 63.8 ppb.

Figure 5. Projected 2010 8-hour ozone Design Values (DVF) Figure 6 presents the ozone source apportionment results, including the boundary conditions. The boundary conditions (BCs) showthe contribution from sources outside the 15 State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/Air Pollution Control Division
12 

### kIn domain (see Figure 4) for a given high ozone day (results vary by day). On this day, ofthe 76.1 ppb ofozone estimated at the monitor, approximately 48 ppb was transported into the 12 

### kIn domain and approximately 8ppb was attributed to sources in the sevencounty Denver Metro area (Morris, et aI, 2008a) while the rest was from othercounties in Colorado orfrom other states. This suggests that, on this day, ozone was generated primarilyby global/continental scale "background" and local sources ofemissions in the DenverMetro area. Transport from nearby states was relatively small.

,-. .a 0.. 0 >::: 0 u I1J >::: 0 N 0 72 64 56 48 40 32 24 16

8 0 run16c.osaUy2010.1204 060729 (2006210) Metric-03M Average >= 70.0 PPB Total Ozone 76.1 (ppb)
- Receptor rfno**~-~----_.~----------~** § + CI '" + IC • BC • EGU • NonEGU • Area iilII OiICas • Nonroad Motor Veh. • BioFire

23 o 0 + + U u 8 IiO + + til Z t:

OSAT Source Regi6hs o (.) z Figure 6. Rocky Flats North source apportionment for 29 July includingboundary conditions.
Conclusions from ozone source apportionmentresults (Morris, et aI, 2008a) vary by day and by location. However, several overall trends emerged, namely:

• Regional ozonetransport into the 12 km domain is the largest contributor, often accounting for more than two-thirds ofthe total ozone; • Atthe Denver Metropolitanmonitors the largestcontributors are Denver Metropolitan metro areamotor vehicle and non-road sources; • Atthe Fort Collins and Greeley monitors, the largest contributors tend to be Larimer and Weld County motorvehicles, non-road sources and oil and gas sources, and DenverMetropolitan sources; • The majority ofthe ozone formed is attributable to anthropogenic NOx emissions. 16 State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-HourOzoneColorado Department ofPublic Health and Environment I Air Pollution Control Division



### In interpreting these results, it is important to keep in mind that the source apportionment results are based on the Denver SIP 2006 modeling episode and are meteorologically dependent For instance, the source apportionment modeling in support ofthe Denver Early Action Compactusing a 2002 ozone episode (Morris, etaI, 2004a) showed more impact from sources in northern Colorado in the Denver Metropolitan area. Other ozone transport studies also confirm that Denver is impactedby ozone from areas well outside ofColorado. A report sponsored by the Western States Air Resources Council (WESTAR) indicates that, when ozone is greaterthan 85 ppb in Denver, natural background accounts for 37.5% ofthetotal concentration, transported anthropogenic generated ozone is 37.5%, and the local anthropogenic ozone contribution is about 25% (MacDonald, et. aI, 2006). A common theme at all ozone monitors is that amajority ofthe peak 8-hour ozone is due to ozone transport from sources outside ofColorado and outside the 12km domain boundary. Source apportionment modeling indicates that transport into the region accounts for approximately 60-75% ofthe ozone formation in the DMAINFR. This indicates that the DMAINFR

### is more ofareceptor ofozone and ozone precursors ratherthan a producer of ozone and precursors that transports ozone to areas outside ofthe Front Range. While the modeling suggests that the transport ofozone andlor ozoneprecursors is a significant issue in the west, the magnitude ofozone transport from Colorado to other states is too low to significantly contribute to nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm ozone NAAQS.

17 State ofColorado Implementation Plan to Meetthe Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(1) • Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division



### 1.5. Denver Metro Area/North Front Range Ozone Nonattainment Area Contribution to Downwind Locations As part ofthe DenverEAC, source apportionment modeling was conducted to evaluate the spatial extent ofthe 8-hourozone impacts due to emissions from various source regions in Colorado. A similar analysis was not done as part ofthe DMA/NFR ozone SIP analysis, however, a similarconclusion would be expected. The conclusion is that ozone formed specifically from sources in the DMA/NFRnonattainment area decreases rapidly in concentration overthe eastern plains ofColorado. Therefore, the photochemical modeling that was done for both the DMA/NFRozone SIP and the Denver EAC suggestthat ozone and/or ozone precursors from the Front Range do not contribute significantlyto downwind monitors in other states. Figure 7 displays the spatial extent ofthe 8-hourozone concentrations that occurred between lOam and 6pm local time (the time when the daily maximum 8-hour ozone typically occur) on June 27,2002 through July 1,2002due to all emissions (anthropogenic and biogenic) from the DMA. As shown in Figure 7, whichrepresents a high ozone episode in Denver, the DMA can contribute approximately 10 ppb ofozone at the eastern border ofColorado. However, the concentration gradient falls offquickly and emissions from the DMA are not expected to be a significant contributorto any ozone nonattaihment area downwind ofthe Front Range. Weld, Elbert, Morgan, Larimer, El Paso and other counties contribute even less ozone to the Colorado border states with a maximum contribution of 5-10 ppb.

18 State ofColorado Implementation PLan to Meet the Requirements of Clean AirAct Section lID (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment! Air Pollution Control Division

ContJ1butions fa 8-hr Ozone Contributionsto 8-hrOzone
#1 0 ..**Dft:nv~r ~I'Qp()Ul4ln**  ATe. trom**D~r",e,.** Mll'tropolitilfl**AA~** CAlAx"".01 2OO1·cntlQ.al.3grd CAtot< 'I'I.lU**1OOI-1:nlJ<l.~.:lgrd** 20.00000 --_.•

15.000 15.000

10.000 10.000

So,OOO

0.000 I**"""""-~** .. > 0.000 rr'o ppa 

### ""n<**V20~** 10;00:00 June 28.2002 10:00100 Min O.«jlh1[lIoIl.np

....·**IS.~fIl'** 01(17.371 l.tIn**O.OS6at(I.'~M"',** 21.(1:JIIII(3:l27) Contributionsto 8-hrOzone Conldbutionllto 8-h.Ozone

I 1).000

10.000

s.ooo

OJlOO I PP8
Contl'ibutions to 8-hrOzonehom l}el1ver MrtropolihnArY-ii**CAMII(y,q.A)~ ~l-cnt"'.a:2.3grd**  ..,..... .., r---,----.,-----Tl

15.000

HJ.OOO
'.OQO



## .. July 1.2002 10iJO:110 ",. Min- OJlOO at 1.Sll1 M
.... :18.21\ 0«:1<1.33) Figure 7: Spatial extent ofthe 8-hour ozoneconcentrationsthat occurred between lOam and 6pm local time on June 27,2002 through July 1,2002

/9 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division 

### 1.6. Section 110(a)(2)(D)(i)(l) - Ozone Transport Conclusions With respectto the 0.08 ppm ozone NAAQS, emission control programs in the Colorado SIP are expected to adequately protectdownwind neighboring states from interstate transport ofozone, per CleanAir Act (CAA) Section 11

### 0(a)(2)(D)(i)(I). Ambient monitoring data in and around Colorado support the assertionthat Colorado does not contribute significantlyto nonattainment in, or interfere with maintenance by, any other state withrespect to the 1997 8-hourozone NAAQS of0.08 ppm. Colorado is unlikely to interfere with maintenance ofthe 8-hour ozone standard in downwind or potentially doWnwind states is supported by monitoring datacollected in neighboring states (see Table 4) and the results ofphotochemical modeling analysis as discussed in Section 1.4.2 and 1.5. Specifically: 1. Ozone concentrations measured at Kansas, Nebraska, and Wyoming monitors closest to Colorado are significantly below the nonattainmentthreshold. In addition, the results ofthe photochemical analysis discussed in the sections noted above show that the ozone values in the easternmost Colorado counties are sufficiently low to make it unlikely for ozone transport from Colorado to interfere with maintenance ofthe 1997 NAAQS in downwind state. 2. A review ofrecent ozone observations from the EPA AQS database shows that, with the exception ofa single monitor in Jefferson County, Colorado (i.e., Rocky Flats North), all monitoring sites in Colorado and adjacent states that are likely to be impacted by Colorado demonstrated attainment ofthe 0.08 ppm 8-hour ozone NAAQS for the three year period of2005-2007. Since ozone monitors in adjacent states comply with the 0.08 ppm NAAQS, it logically follows that Colorado does not cause or contribute to monitored violations or interfere with maintenance ofthe 0.08 ppm ozone NAAQS in any other state. 3. For Rocky Flats North, which is the only monitor in Colorado that has levels above the 0.08 ppm ozone NAAQS, the preliminary three-year average (2006-2008) fourth high value is 0.086 partsper million (ppm), which is only slightly above the 0.08 ppm ozone NAAQS.

. 4. Observations from current networks showthat the highest ozone levels in Colorado occur along the Colorado Front Range and not in other areas ofColorado. 5.0zone monitoring data from the surrounding states that are most likelyto be impacted by Colorado (i.e., Nebraska, Kansas, NewMexico, Wyoming, and Utah) showthat none ofthe monitors exceed the 0.08 ppm 8-hour ozone standard. Since the areas represented by these monitors are in monitored attainment, it is higWy unlikely that existing 0.08 ppm ozone nonattainment areas beyond these areas are significantly affected by emissions from Colorado. The nearest 0.08 ppm ozone nonattainment areas to DMAlNFRNonattainment Area are: a. Phoenix, Arizona (Basic Area for 8-Hour ozone) at a distance of586 miles; 20 State ofColorado Implementation Plan to Meet the Requirements of Clean Air Act Section 110 (aX2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment IAir Pollution Control Division
b. Las Vegas, Nevada (Basic Area for 8-hour ozone) at a distance of628 miles; c. Dallas, Texas (Moderate 8-hour ozone nonattainment area) at a distance of 663 miles; and d. St. Louis, Missouri (Moderate 8-hour ozone nonattainment area) at a distance of796 miles. Photochemical modeling and other technical analyses performed for the Denver Early Action Compact (EAC) and the Denver Metro Area and North Front Range (DMA/NFR) 8-hour Ozone SIP supportthe assertion that Colorado does not contribute significantlyto nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm ozone NAAQS. Specifically: 1. The Denver 8-hour Ozone SIP photochemical modeling for 2010 and the associated weight ofevidence analyses suggest that the DMA/NFRnonattainment area and downwind areas already comply or will comply with the 0.08 ppm ozoneNAAQS by2010. 2. Photochemical modeling shows that elevated ozone concentration levels generated from local emissions decrease rapidly with distance. 3. A review ofphotochemical modeling performed for both the DMA/NFR Ozone SIP andthe Denver EAC, includingboundary condition analyses, suggests that the magnitude ofozone transport from Colorado to other states is too lowto significantly contributeto nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm ozone NAAQS. In summary, a review ofmonitoring data, photochemical modeling, and weight ofevidence analyses generated for the DMA/NFR SIP process suggests that the transport ofozone and ozoneprecursors from Colorado does not cause or significantly contribute to nonattainment in, or interfere with maintenance by, any other state with respect to the 0.08 ppm 8-hour ozone NAAQS. This analysis does not address ozonetransportfor the revised 0.075 ppm 8-Hour OzoneNAAQS.



### 21 State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(l) • Interstate Transport Regarding 8-Hour OzoneColorado Department ofPublic Health and Environment/ Air Pollution Control Division 

# 2. REFERENCES Coats, C.J. Jr. "High-performance algorithms in the Sparse Matrix OperatorKernel Emissions (SMOKE) modelingsystem." Proc. NinthAMSJoint Conference onApplicationsof Air PollutionMeteorology withAWMA. Amer. Meteor. Soc., Atlanta, GA, 584-588. 1996. ENVIRON. User's Guide

- Comprehensive Air Quality Model with Extensions

- Version 4.40. ENVIRON International Corporation, Novato, CAhttp://www.carnx.com. February 2008. Loomis, C., 1. Wilkinson, J. Haasbeek, A. Pollackand M. Jansen. 2005. "ConCEPTConsolidated CommunityEmissionsProcessing Tool, An Open-Source Toolfor the Emissions Modeling Community." Presented atthe 14thInternational Emission Inventory Conference "TransformingEmission Inventories

- Meeting Future Challenges Today", Las Vegas, Nevada, April 11- 14. <http://www.epa.gov/ttn/chief/conference/ei14/sessionl1/loomis.pdf> MacDonald, C., Miller, D., Raffuse, S., 2006. Regional and Local Contributions to PeakLocal Ozone Concentrations in Six WesternCities. Sonoma, Technology, Inc., Petaluma, CA. Prepared for WESTARCouncil ofGovernments

.. May 16 Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008a. 2010 Ozone Projectionsfor the 2010Base Case and2010Sensitivity Tests and2010 Ozone Source ApportionmentModelingfor the Denver 8-Hour Ozone State Implementation Plan. ENVIRON International Corporation, Novato, California. Prepared for DenverRegional Air Quality Council (RAQC), Denver, Colorado. September 8. Morris R., E. Tai, Tanarit Sakulyanontvittaya, D. McNally and C. Loomis. 2008b. 2010 Ozone AttainmentDemonstration Modelingfor the Denver8-Hour Ozone State Implementation Plan ControlStrategy. ENVIRON International Corporation, Novato, California. Preparedfor DenverRegional Air Quality Council (RAQC), Denver, Colorado. September22. Morris, R.E., G.E. Mansell, E. Tai, D.A. McNally and T.W. Tesche. 2004a.Air Quality ModelingAnalysis for the DenverEarlyAction Compact: Ozone SourceApportionment Modelingfor the DenverEAC. Prepared for the Colorado Department ofHealth and Environment andDenverRegional Air Quality Council, Denver, Colorado. Preparedby ENVIRON International Corporation, Novato, CA. May 31

.. Utah Air Quality Board, 8-Hour Ozone Maintenance ProvisionforSaltLake andDavis Counties, January 

### 3, 2007.

22 State ofColorado Implementation Plan to Meet the Requirements of Clean AirAct Section 110 (a)(2)(D)(i)(I)

- Interstate Transport Regarding 8-Hour Ozone

# Final AdoptionNotice

# STATE OF COLORA.DO

Bill Ritter, Jr., Governor James B. Martin, Executive Director Dedicated to protecting and improving the health and environment of the people of Colorado 4300 Cherry Creek Dr. S. Laboratory Services Division Denver, Colorado 80246-1530 8100 Lowry Blvd. Phone (303) 692-2000 Denver, Colorado 80230-6928 TOO Line (303) 691-7700 (303) 692-3090 ColoradoDepartment Located in Glendale, Colorado ofPublicHealth http://www.cdphe.state.co.us andEnvironment

NOTICE OFFINAL ADOPTION PURSUANT to the provisions ofsections 25-7-105,25-7-105(12),25-7-114 through 25-7-114.7, 25-7­ 106,25-7-119 and 25-7-132 C.R.S. ofthe Colorado Pollution Prevention and Control Act. NOTICE IS HEREBY GIVEN that after a public rulemaking hearing December 12,2008, and in compliance with the requirements ofsections 25-7-105, 25-7-110, and 25-7-110.5, C.R.S., the Colorado Air Quality Control Commission made revisions to: Interstate Air PollutantTransport State Implementation Plan The Commission adopted revisions to an ozone action plan for the Denver Metropolitan and North Front Range 8-hour ozone nonattainment area. The ozone action plan modified the provisions ofthe Interstate AirPollutantTransport State Implementation Plan elementadopted by the Commission in February 2007, by noting thatthe proposed maintenance plan would preventthe Colorado FrontRange from contributing significantly to ozone non-attainment or interfere with long-term maintenance ofthe national ozone standard in any other state. This action was submitted to the Secretary ofState's Office within 20 days after adoption for publication in the Colorado Register, pursuant to 24-4-103(5) and (11)(d), C.R.S., and will become effectiveJanuary 30,2009. Additionally, pursuantto 24-4-103(8)(d), C.R.S., within 20 days afterthe date ofthe Attorney General's Opinion, this action will be submittedto the Office ofLegislative Legal Services for review.

# Opinion ofthe Attorney General

NotApplicable

# Regulation as Published inthe CCR (this is the version that is publishedby LexisNexis)



# NotApplicable