Western Regional Ozone Issues

Observations and concerns Changing perspective- not all isolated

ozone issues Trends in Colorado areas Near non-attainment and excessions of

the standard Transport versus local Rural sources versus urban

1995 Forest Ozone Paper

Bohm, McCune & Vandetta, JAWMA, June 1995 published two papers identifying impact on rural Western Forests from transport, non-urban ozone formation or tropospheric reservoir downward mixing

Observations and Concerns

Nationally, 1-hour ozone levels have declined over the past 20 years as VOC and NOx emissions have been reduced

Many areas met the 1-hour standard AND…

National Trends

National 8-hour ozone trends show a 14% decrease in composite 4th maximum levels over the past 20 years

However:– Trends over the past 10 years show a 4%

ozone increase while a subset of meteorologically adjusted sites show no change even with decreasing VOCs

Regional Trends

The Pacific Southwest – LA area- indicates substantial improvements in 8-hour ozone over the past twenty years

BUT- the Pacific Northwest indicates ozone levels are increasing

AND- trends at individual more rural locations show mixed trends over the past ten years

Western Emissions and Non-Attainment Texas and California rank #1 and #2 for

total Western Emissions of VOC’s and NOx

There are only two other Western N/A areas with substantially lower VOC and NOx emissions

Other Western States have comparable emissions but meet the standards

Emissions & Rank of Western States With Ozone Issues

State Western Rank

1996 NEI

NOx TPY VOC TPY

Texas 1 2,202,935 1,451,353

California 2 1,556,374 1,213,033

Arizona 3/5 463,034 312,039

Colorado 4/6 425,539 298,347

New Mexico

6/8 324,939 155,835

Western Non-Attainment Areas

Western Non-Attainment Areas

Threatened Non-attainment Areas of Colorado

8-hour Ozone --- 4th Max.Northern Colorado

0.000

0.020

0.040

0.060

0.080

0.100

1995 1996 1997 1998 1999 2000 2001 2002 2003

Year

pp

m

RMNP Ft. Collins Greeley Weld Co. Tower

Rural Ozone VS Urban

8-hour Ozone --- 4th Max.Southern Colorado

0.0000.0200.0400.0600.0800.100

1995 1996 1997 1998 1999 2000 2001 2002 2003

Year

pp

m

Colo. Spgs.-Tejon Colo. Spgs.-Academy

Other rural trends?

8-hour Ozone --- 3-year Avg. of 4th Max.Southwestern Colorado

0.040

0.060

0.080

0.100

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Year

pp

m

Ute-Ignacio Ute-Hwy. 550 MVNP

thru7/23

Standard

8-hour Ozone --- 3-year Avg. of 4th Max.Denver metro area (west)

0.040

0.060

0.080

0.10019

92

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Year

pp

m

Chatfield Welch Rocky Flats-N NREL

thru8/31

Standard

Denver High Station Trend

8-hour Ozone --- 3-year Avg. of 4th Max.Denver metro area (core)

0.040

0.060

0.080

0.10019

92

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Year

pp

m

CAMP Carriage Arvada

thru8/31

Standard

Denver Core Site Trend

8-hour Ozone --- 3-year Avg. of 4th Max.Denver metro area (north and south)

0.040

0.060

0.080

0.100

Year

pp

m

Welby Highland S. Bldr. Ck. Boulder

thru8/31

Standard

Denver North South Trends

Episodes and Background

Urban Denver ozone once thought to be isolated to the dynamics of front range emissions, topography and photochemistry

Current analysis indicates episodes of high ozone can be a combination of long range transported ozone mixed with rural and urban components

Back Trajectory Analysis- AQI 119- NOAA Air Resources Laboratory

Emissions VOC and NOx

Front range emissions have a substantial local source component

Statewide VOC emissions are dominated by biogenic sources

Future emissions are expected to decline only slightly

2002 Denver Metro and Statewide NOx EI with Biogenicand Wildfire Emissions

Point Sources26 %

Area Sources6 %

Non-Road (exhaust)22 %

M obile Sources (exhaus t)36 %

Biogenic8 %

W i ldfire2 %

D env er EAC -2 002 N itrogen Oxides (NOx ) Em is sions fo r th e D e nver Area + We ld C oun ty+ B io genic Em iss ion s and Wi ld fire

(To ta l N Ox= 407 tp d)

Point S ources28 %

Area Sources5 %

Non-Road (ex haust)15 %

M obile Sources (ex haus t)26 %

Biogenic22 %

W i ldfire3 %

D enve r EAC -2 002 Sta tew ide N itrogen Oxides (N Ox ) Em is sions+ Biogenic Em is sions and W ild fi re

(Tota l N Ox= 1159 tpd)

2002 Denver Metro and Statewide VOC

EI with Biogenic Emissions

Point Sources7 %

Point Sources-F lash15 %

Area Sources11 %

N on-R oad (exhaust)7 %

N on-R oad (evaporative)1 %

M obile Sources (exhaust)9 %

M obile Sources (evaporative)8 %

B iogenic43 %

D e n ve r EAC -2 0 0 2 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 w ith B iog e n ic Em issio n s

(To ta l H C =8 9 3 tp d )

Point Sources2 %

Point Sources-F lash2 %

Area Sources3 %

N on-R oad (exhaust)2 %N on-R oad (evaporative)0 %

M obile Sources (exhaust)2 %

M obile Sources (evaporative)2 %

B iogenic88 %

D e n ve r EAC -2 0 0 2 S ta te w id e H yd ro ca rb o n Em issio n s+ B io g e n ic Em issio n s a n d W ild fire

(To ta l H C = 7 3 7 8 tp d )

Existing O&G Sources in the San Juan Basin 22,500 existing

sources- VOC’s and NOx

11,000 proposed new O&G sources

New Mexico Ozone Task Force

Only other Early Action Compact area of the West

Recognized signs of possible ozone problems

Establishes a stepping stone for coordination of multi-State or Interstate ozone issue