Front Range OzoneEarly Action Compact

Presentation to WESTAR Regional Ozone Conference

Steven ArnoldAir Pollution Control Division

March 9th, 2004

Overview Denver’s Ozone Problem Sources The Early Action Compact Non-Attainment Boundary Control Actions

2000 2001 2002 2003 2000-2002 2001-20038-hr. O3 8-hr. O3 8-hr. O3 8-hr. O3 3-yr. Avg. 3-yr. Avg.4th Max. 4th Max. 4th Max. 4th Max. 4th Max. 4th Max.

Value Value Value Value Value ValueSite Name (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)

Welby 0.062 0.064 0.068 0.066 0.065 0.066Highland 0.076 0.077 0.076 0.091 0.076 0.081S. Boulder Creek 0.072 0.071 0.078 0.082 0.074 0.077Carriage 0.071 0.072 0.073 0.085 0.072 0.077Chatfield Res. 0.080 0.077 0.083 0.095 0.080 0.085USAF Academy 0.072 0.07 0.072 0.077 0.071 0.073Arvada 0.076 0.074 0.073 0.083 0.074 0.077Welch 0.068 0.064 0.069 0.077 0.067 0.070Rocky Flats North 0.081 0.082 0.088 0.091 0.084 0.087NREL 0.083 0.081 0.081 0.095 0.082 0.085Fort Collins 0.070 0.067 0.072 0.075 0.070 0.071Greeley 0.069 0.074 (Shut dow n) (Shut dow n) --- ---Rocky Mtn. N.P. 0.078 0.070 0.087 0.087 0.078 0.081Weld County Tower --- --- (0.080) (0.083) (0.080) (0.082)

Ozone Summary

Ozone Status

20043-yr. Avg. Highest4th Max. Allowable

Value 4th Max.(ppm) (ppm)

0.066 0.1200.081 0.0870.077 0.0940.076 0.0960.085 0.0760.073 0.1050.076 0.0980.070 0.1080.087 0.0750.085 0.0780.071 0.107

--- ---(0.080) (0.094)

0.081 0.080

Site Name

WelbyHighlandS. Boulder CreekCarriageChatfield Res.USAF AcademyArvadaWelchRocky Flats NorthNRELFort CollinsGreeleyWeld County Tower

Rocky Mtn. NP

Upslope Meteorology

Ozone averaging morethan 80 ppb between10,000 and 18,000feet represents carry-over from the previousday and/or transport.

This ozone would havebeen available formixing throughout themixed layer during thelate afternoon, contributing to the ozone burden at thesurface.

Back Trajectory Analysis- AQI 177- NOAA Air Resources Laboratory

Back Trajectory Analysis-AQI 129- NOAA Air Resources Laboratory

Back Trajectory Analysis-AQI 101- NOAA Air Resources Laboratory

Topography (Denver Boulder Greeley CMSA Highlighted)

Denver Metro + Weld County VOC Emission Inventory

Poin t Sources12 %

Poin t Sources-F lash26 %

Area Sources19 %

N on-R oad (exhaust)12 %

N on-R oad (evaporative)2 %

M obile Sources (exhaust)15 %

M obile Sources (evaporative)14 %

D e n ve r EAC -2 0 0 2 H yd ro ca rb o n Em ission s fo r th e D e n ve r A re a + W e ld C o u n ty (To ta l H C =5 1 1 tp d )

Point Sources12 %

Point Sources-F lash31 %

Area Sources22 %

N on-Road (exhaust)10 %

N on-Road (evaporative)1 %

M obile Sources (exhaust)10 %

M obile Sources (evaporative)14 %

D e n ve r EAC -2 0 0 7 H yd ro ca rb o n Em issio n s fo r th e D e n ve r A re a + W e ld C o u n ty (To ta l H C = 4 7 5 tp d )

Denver Metro + Weld County NOx Emission Inventory

Point Sources29 %

Area Sources7 %

N on-R oad (exhaust)24 %

M obile Sources (exhaust)40 %

D e n ve r EAC -2 0 0 2 N itro g e n Oxid e s (N Ox) Em issio n s fo r th e D e n ve r A re a + W e ld C o u n ty (To ta l N Ox= 3 6 3 tp d )

Point Sources33 %

Area Sources9 %

N on-R oad (exhaust)25 %

M obile Sources (exhaust)33 %

D e n ve r EAC -2 0 0 7 N itro g e n Oxid e s (N Ox) Em issio n s fo r th e D e n ve r A re a + W e ld C o u n ty (To ta l N Ox= 32 4 tp d )

To avoid nonattainment, the Denver area entered into the Early Action Compact A multi-agency agreement

RAQC, CDOT, AQCC, EPA, DRCOG, CDPHE, and Elbert, Larimer, Morgan and Weld Counties

Controls implemented faster than traditional process

Requires complex modeling Requires implementing controls by 12/31/05 Success must be shown by 12/31/07 – attainment

Early Action Compact

Joining the EAC ensures a nonattainment designation will be deferred for all counties Control over control measures No transportation or general conformity No nonattainment NSR permitting requirements No RACT for all stationary sources No “nonattainment” stigma Basically, an “insurance policy” from nonattainment

Failure to meet any of the EAC deadlines triggers automatic activation of nonattainment

Early Action Compact

3/11 - AQCC public hearing

3-5/04 - Legislative review of AQCC adopted SIP

4/15/04 - EPA finalizes designation (deferred) and boundaries

12/31/04 - Plan due to EPA

Overview of the EAC Schedule

If an area violates the standard, then EPA designates “nonattainment”

A State Implementation Plan (SIP) is required SIP = control strategy plan with technical

information Emission controls must be enforceable Conformity and more stringent source

controls

The Concept of Nonattainment

EPA guidance recommends a minimum nonattainment boundary as the Denver/Boulder/Greeley CMSA

Also, the CAA requires the area to include “…the area that can be shown to cause or contribute to nonattainment…”

Review of sources, modeling, topography, and meteorology are considered in determining the boundaries

Potential Ozone Nonattainment Boundary

New Boundary May Include

North Front Range Counties

Sources in many counties may “cause or contribute” to violations

Weld County and RMNP monitors are perilously close to recording violations

EPA recommends 11 counties as the 8-hour ozone nonattainment area Adams, Arapahoe, Boulder, Broomfield, Denver,

Douglas, Elbert, Jefferson, Larimer, Morgan and Weld

CDPHE responded to EPA proposal Shave off northern Larimer and Weld Counties, all

of Elbert County, and eastern Morgan, Weld, Adams, and Arapahoe Counties from boundary

Proposed 8-hour Ozone Nonattainment

Area

Eastern Colorado VOC Sources (Denver Boulder Greeley CMSA Highlighted)

Eastern Colorado NOx Sources (Denver Boulder Greeley CMSA Highlighted)

Oil/Gas Activities(from Colorado Oil and Gas Conservation

Commission)

Purple: Permits

Green/Red: All Oil/Gas

Wells

Eastern Colorado Oil and Gas (Denver Boulder Greeley CMSA Highlighted)

1.3 -km Grid

4-km Grid

12-km Grid

200 0 200 Miles

N

EW

S

Modeling Domain for the Denver Ozone EAC

Ozone Modeling Area for EAC

Development of theOzone Plan

A plan has been drafted and proposed to the Air Quality Control Commission Description of the problem Accounting of all emission sources

(“inventories”) Photochemical modeling to predict success

by 2008

Controls on certain sources proposed Flash emissions from oil/gas sources 8.1 psi RVP gasoline

EPA may set RVP at 7.8 psi Uncontrolled industrial engines Natural gas processing plants Dehydrators at oil/gas operations Current controls remain in place

Enhanced I/M, federal measures, existing stationary sources rules

Development of theOzone Plan

Modeling these reductions shows improvement, but not enough All monitoring sites below 85 ppb in 2007 except the

Rocky Flats site – 85.6 ppb “Weight of the evidence” used to show attainment

Used if modeled concentrations less than 90 ppb Corroborative analysis of modeling results/uncertainties,

emissions trends, anomalous meteorology, levels of control

Attainment presumed based on the proposed plan AQCC hearing March 11th; Legislature then reviews

Development of theOzone Plan

What Next? Monitoring this summer will provide

new perspectives Modeling will continue to be refined Legislative session and AQCC Actions

are only Round 1 EPA actions and actions of 22 parties

and other interests are all unknowns