Annual Data Summary 2007

 Gaseous Pollutant Monitoring Program

 Ozone, Sulfur Dioxide, Particulate Matter, 

 Meteorological Observations

 Natural Resource Report NPS/NRPC/ARD/NRR—2008/065

 

 National Park Service

 U.S. Department of the Interior

 Natural Resource Program Center
ON THE COVER

Arches National Park, Utah

Courthouse Towers

Photograph by Debbie Miller/NPS
Annual Data Summary 2007

Gaseous Pollutant Monitoring Program

Ozone, Sulfur Dioxide, Particulate Matter, 

Meteorological Observations

Natural Resource Report NPS/NRPC/ARD/NRR—2008/065

John D. Ray, Ph.D.

National Park Service Air Resources Division, Gaseous Pollutant Monitoring Program

P.O. Box 25287

Denver, CO 80225

October 2008

U.S. Department of the Interior

National Park Service

Natural Resource Program Center

Denver, Colorado
 ii 

The Natural Resource Publication series addresses Natural Resource topics that are of interest and applicability to a 

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array of reports published in this series include vital signs monitoring plans; “how to” resource management papers; 

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of the U.S. Department of the Interior, NPS. Mention of trade names or commercial products does not constitute 

endorsement or recommendation for use by the National Park Service.

This annual data summary was prepared for the National Park Service under contract C2350064024 by Air Resource 

Specialists, Inc., Fort Collins, Colorado.

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supply lasts. This report is also available from the Natural Resource Publications Management Web site (http://www.

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Internet, or by sending a request to the address on the back cover. 

Please cite this publication as:

Ray, J. D. 2008. Annual data summary 2007: Gaseous Pollutant Monitoring Program, National Park Service Air 

Resources Division. Natural Resource Report NPS/NRPC/ARD/NRR—2008/065. National Park Service, Denver, 

Colorado.

NPS D-2017, October 2008

Printed on recycled paper
 iii 

List of Figures .............................................. iv

List of Tables ................................................v

Foreword ..................................vii 

 

Introduction ................................1

Network Description ..................3

 GPMP Network Monitoring .................3

 Cooperating Programs .........................3

 

Data Summaries .......................11

 Ozone Data Summaries .....................12

 Implications of the New

 National Ambient Air Quality 

 Standard ............................................21

 Resource Injury Indices .......................32

 Sulfur Dioxide Data Summaries ..........37

 Particulate Matter Data Summaries ....39

 Meteorological Data Summaries ........43

Contents

Photographs

Sequoia-Kings Canyon NPs ......................... iv

Rocky Mountain NP .....................................v

Great Smoky Mountains NP ....................... vii

Zion NP ......................................................2

Mount Rainier NP .........................................4

Glacier NP ..................................................12

Black Canyon of the Gunnison NP ..............18

Bryce Canyon NP .......................................41

Wind Cave NP ...........................................43
 iv 

Figure 1. 2007 Air quality monitoring 

in or nearby park units ...............................5

Figure 2. 2007 Annual fourth highest 

daily maximum 8-hour average 

ozone concentrations (in ppb) ..................15

Figure 3. 2007 Annual number of days 

with daily maximum 8-hour 

average ozone values ≥85 ppb .................16

Figure 4. 2007 Annual second highest

1-hour average ozone 

concentrations (in ppb) ............................17

Figure 5. Park units that will violate

the new ozone NAAQS based on NPS 

monitoring network data .........................22

Figure 6. Counties and park units with

monitoring data that support a possible

violation of the new ozone NAAQS of 

75 ppb. Only counties with NPS

monitors or park units are shown. See

Figure 9 for the urban counties EPA 

expects will violate the new standard .......25

Figure 7. Interpolations of monitoring

data from the Air Atlas program. Yellow 

to red areas are projected to violate the 

new standard. ..........................................26

Figure 8. Violation areas are extracted

from the Figure 6 map and the parks in

the violation areas are shown ...................27

Figure 9. This map combines the 

counties EPA projects to violate the 

new standard (orange) and the 

counties projected from Air Atlas

(rose color) as potentially in 

violation. The red, blue, and gray

 dots are park locations. Many rural 

counties have the potential to violate

the standard ............................................28

Figure 10. The counties highlighted

in green have both park unit(s) and a

monitor in the county (black dots) ............29

Figure 11. 2007 3-month maximum 

W126 exposure index during the 

ozone season (0800-2000 hourly

concentrations) ....................................... 35

Figure 12. 2007 3-month maximum 

SUM06 exposure index during the 

ozone season (0800-2000 

hourly concentrations) ............................ 36

Figures

Sequoia-Kings Canyon 

National Parks, California

Alta Meadow

Photo by Laura Weber/

Air Resource Specialists, Inc.
 v 

Table 1. 2007 Site Specifi cations .............. 6

Table 2. 2007 Summary of 8-hour 

average ozone concentrations (ppb) ........ 13

Table 3. 2007 Ozone violation 

summary - primary standard ................... 19

Table 4. Parks that violate the new 

ozone NAAQS for 3-year average

annual 4th highest 8-hour ozone (ppb) .... 21

Table 5. Parks with monitoring data

that are close to the new 

NAAQS of 75 ppb ................................... 22

Table 6. Portable ozone data (POMS) 

indicate several parks with high ozone

(bold values exceed the standard) ........... 23

Table 7. NPS units within 5 miles of an 

ozone monitor and 2005-2007 average .. 24

Table 8. Frequency of exceedances (mean 

number of days) where the daily maximum 

8 -hour average was greater than 75 ppb 

based on 2005-2007 data. This mean is 

based on a simple count of the days. No 

annual completeness criteria (such as a 

minimum number of valid daily 8-hour 

maximums) were applied ........................ 30

Rocky Mountain National Park, 

Colorado

Longs Peak

Photo by Jessica Ward/

Air Resource Specialists, Inc.

Tables

Table 9. Ozone violation severity can 

also be judged by the frequency of

events ........................................................ 31

Table 10. W126 and SUM06 thresholds 

for ozone effects to vegetation 

 (based on 3-month, 12-hour exposure) ..... 32

Table 11. 2007 Summary of indices for 

resource injury (W126 and SUM06) ............ 33

Table 12. 2007 Summary of sulfur 

dioxide data ............................................... 38

Table 13. 2007 Summary of PM2.5 data 

from reference and equivalency methods ... 40

Table 14. 2007 Summary of PM10 data 

from reference and equivalency methods ... 42

Table 15. 2007 Summary of PM10 data 

from non-equivalency methods .................. 42

Table 16. 2007 PM10 summary - 

maximum daily 24-hour average 

concentration in 2007 (μg/m3) ................... 42

Table 17. 2007 Summary of selected 

meteorological data ................................... 44

 vii 

Air quality and meteorological data from 

National Park Service (NPS) monitoring 

sites for 2007 has been fully validated 

and made available to the Environmental 

Protection Agency (EPA), the parks, and 

the public. This report provides summary 

tables and graphics to help understand how 

the measured pollutant concentrations 

compare to National Ambient Air Quality 

Standards and to concentrations measured 

in previous years. Additional tables and 

graphs can be viewed and hourly data 

retrieved from the NPS Air Resources 

Division (ARD) Web site (http://www.

nature.nps.gov/air/monitoring/index.cfm/). 

Report Changes in 2007

EPA proposed a new ozone standard in 

2007 and promulgated a new standard on 

March 12, 2008 of 75 ppb. A section of this 

report has been devoted to a summary on 

parks that could possibly be aff ected by this 

lower, more protective standard. Under 

the new standard, many parks will likely 

be in non-attainment and fall under the 

State Implementation Plans for improving 

air quality. Park visitors should consider 

the possibility of adverse health eff ects due 

to poor air quality, especially if they are 

sensitive to respiratory stresses. More parks 

should consider issuing ozone advisories to 

alert visitors when high concentrations are 

present. Review the tables and summaries 

in this report to determine where your park 

stands in the ozone rankings.

Proposed Monitoring Strategy

The ARD has looked at anticipated budgets 

for fi ve years into the future and has started 

to adjust programs accordingly. Monitoring 

plans have been formulated around a new 

proposed monitoring strategy and updated 

objectives. Some monitoring will be 

eliminated, some types of monitoring will 

be expanded, new parameters will be added, 

and new tools will be applied to gathering 

data. 

Portable Ozone Monitoring Systems

The portable ozone monitoring systems 

(POMS) continue to be used and the 

program expanded. The self-contained 

ozone monitoring systems can be placed 

in a wide variety of locations because 

they use solar power and satellite data 

communications along with a small, lowpower ozone analyzer. The NPS Inventory 

and Monitoring program is beginning to use 

more POMS to fi ll in baseline data at park 

locations that previously have not had air 

quality monitoring. 

Highlights in 2007

During 2007, 13 sites in or near 10 park units 

exceeded the 8-hour ozone standard, as 

indicated in the table below. An exceedance 

occurs when an 8-hour average ozone 

concentration is equal to or greater than 85 

ppb. Five parks violated the ozone standard 

based on the 3-year averages. Thirteen 

monitors had one or more exceedances of 

the ozone standard during the year. SequoiaKings Canyon and Joshua Tree continue 

to have the most ozone exceedances. Of 

the parks that monitor sulfur dioxide, only 

Hawaii Volcanoes violated the sulfur dioxide 

standard. This is a result of toxic gas venting 

from Kilauea volcano rather than from 

anthropogenic sources. 

 

Foreword
 viii 

Network Quality Assurance

Overall data capture for NPS ozone 

monitoring continues to be high (94%) 

and exceeds NPS objectives and EPA 

requirements. The EPA accepts data from 

the NPS ARD as high quality and uses them 

to determine park areas that are in violation 

of the standards and in non-attainment. 

NPS data are used in peer-reviewed 

publications and in several government 

agency reports, and are submitted to the 

EPA Air Quality System (AQS) database 

(http://www.epa.gov/air/data/) and to 

AIRNow for presentation daily on the Web 

(http://airnow.gov).

Park/Site

4th Highest Daily Maximum

8-Hour Avg. O3

Concentration (ppb)

Number of 

Exceedances

Acadia - Cadillac Mountain

Cuyahoga Valley

Death Valley

Great Smoky Mountains:

 Clingmans Dome

 Cove Mountain

 Look Rock

Guilford Courthouse

Indiana Dunes - Ammunition Bunker

Joshua Tree - Black Rock

Saugus Iron Works

Sequoia and Kings Canyon:

 Ash Mountain

 Lower Kaweah

Yosemite - Turtleback Dome

86

90

85

87

88

88

86

85

104

88

99

91

88

5

9

6

9

5

11

4

4

40

4

44

25

8

Great Smoky Mountains National 

Park, North Carolina/Tennessee

Purchase Knob

Photo by Joe Adlhoch/

Air Resource Specialists, Inc.

The Gaseous Pollutant Monitoring Program 

(GPMP) acknowledges and thanks all the 

park employees who perform the station 

checks and keep everything operating 

smoothly. Air quality monitoring would not 

be possible without your help. Thank you 

for a job well done.

Dr. John D. Ray

GPMP Program Manager

NPS Air Resources Division

303-969-2820

john_d_ray@nps.gov

1

The National Park Service Air Resources 

Division (NPS ARD) is responsible for 

providing policy and technical support 

to national parks on air quality issues. 

NPS ARD has established monitoring 

networks for gaseous pollutants, wet and 

dry deposition, and visibility. This 2007 

annual data summary report summarizes 

data from the ozone monitoring network. 

Dry deposition data are summarized by 

the Clean Air Status and Trends Network 

(CASTNet); wet deposition by the National 

Atmospheric Deposition Program 

(NADP); and visibility by the Interagency 

Monitoring of Visual Environments 

(IMPROVE) program. 

The NPS monitoring objectives call for 

the collection of data to support the 

National Park Service’s involvement in 

both the development of state air quality 

control plans, and the evaluation of permit 

applications for new or expanding air 

pollution sources wishing to locate near 

park units. The Clean Air Act gives federal 

land managers an affi rmative responsibility 

to protect air quality related values in Class I 

areas and to assess whether new sources will 

have an adverse impact on park resources 

and values. Information on air quality in 

NPS units can also be used to evaluate the 

performance of atmospheric models that 

simulate transport and impacts of pollutants. 

To meet these objectives the NPS ARD 

has established an air quality monitoring 

program. This data summary report presents 

only ozone (O3), sulfur dioxide (SO2), 

particulate matter (PM), and meteorological 

data from continuous monitors that report 

hourly data. Other gas, particulate, and 

precipitation monitoring are performed 

under the visibility and deposition programs 

and are reported separately. 

Ozone, meteorological, and some SO2

monitoring methods and quality assurance 

procedures adopted by the GPMP network 

were developed in accordance with the EPA 

regulations of 40 CFR, Part 58, Appendix D. 

These regulations, although addressing 

primarily health-eff ects based monitoring 

in areas of high population, are generally 

pertinent to the GPMP. These design criteria 

allow for the direct comparison of data 

collected by the NPS with that collected by 

the EPA, and state and local air pollution 

control agencies. As a supplement to the 

basic network, the ARD also conducts 

short-term air quality monitoring including 

portable ozone and special studies 

monitoring in selected parks. In addition, 

Air Resources Division

Air Quality Monitoring Objectives

Provide data to make pollutant risk assessments of adverse effects to natural resources 

(Air Quality Related Values)

Provide data related to National Ambient Air Quality Standards (NAAQS) and New Source 

Review 

Determine trends that assist in compliance predictions, policy objectives, and regional 

assessments

Provide specifi c answers from special studies that assist modeling, regional pollution transport 

issues, State Implementation Plan (SIP) development, and national control strategies

Provide timely information to the public and researchers to assess current conditions in parks

•

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•

Introduction

The overall purpose of the National Park 

Service Gaseous Pollutant Monitoring 

Program (GPMP) is to monitor the 

status and trends of ambient air quality 

conditions in national park units. This 

purpose is outlined by the Clean Air Act 

of 1977 (and 1990 amendments) and the 

Organic Act of 1916, which assign the 

federal land managers the responsibility of 

protecting the natural resources in national 

parks. Several monitoring objectives have 

been derived from this purpose.
 2

the ARD cooperates with other national 

and state programs that monitor ambient 

gases, meteorology, deposition chemistry, 

particulate matter, and visibility.

Data collected by this network are 

incorporated in the EPA Air Quality 

System (AQS) database, which is a national 

database of air quality data collected 

throughout the country. These data are 

also stored in the NPS ARD’s Information 

Management Center (IMC), and are 

publicly available through the NPS ARD’s 

Web site at http://www.nature.nps.gov/air/

Monitoring/network.cfm#data.

Zion National Park, Utah

Waterfalls

Photo by Joe Adlhoch/

Air Resource Specialists, Inc.
3

The NPS air quality monitoring strategy 

has focused primarily on Class I areas 

defi ned by the Clean Air Act Amendments 

of 1977. The GPMP network consists of 

individual stations located in park units 

throughout the United States. The NPS 

also participates with other agencies in 

cooperative monitoring programs. This 

section describes the GPMP network and 

cooperating programs.

GPMP Network Monitoring

During 2007, 84 monitoring sites in 

61 units of the National Park System 

conducted some combination of ozone, 

sulfur dioxide, particulate matter, and 

meteorological monitoring. Of these, the 

NPS ARD supported 47 monitoring sites 

in 39 units. The locations of the sites that 

operated during the year are presented 

on the map in Figure 1. The parameters 

monitored at each park unit are indicated 

with colored fl ags. The CASTNet fl ag 

identifi es sites where the NPS operates 

Clean Air Status and Trends Network 

monitoring systems in cooperation 

with EPA to estimate dry atmospheric 

deposition. The enhanced gaseous and/or 

particulates fl ag indicates that the NPS 

sponsors additional or high-resolution 

gaseous or particulate monitoring at the 

park. Monitoring agencies and park units 

with more than one monitoring site are 

indicated. Site specifi cations, including site 

names, abbreviations, AQS identifi cation 

numbers, locations, and monitored 

parameters are listed in Table 1.

In addition to monitoring for regulatory 

compliance, the NPS added non-certifi ed 

portable ozone monitoring systems 

(POMS) to the GPMP in 2003. These sites 

employ portable ozone analyzers and 

meteorological sensors, generally confi gured 

for solar and battery power. The POMS 

monitors have been extensively tested 

and compared to other NPS monitoring 

equipment. The data are equivalent to the 

certifi ed monitors and can be used for 

survey monitoring to obtain air quality 

baseline information. Throughout this 

report, POMS site names in tables and 

fi gures have been underlined to distinguish 

them from monitoring sites meeting all EPA 

guidelines.

Cooperating Programs

Data from cooperating programs are 

reported by those programs and are not 

included in this report. The exception to 

that is ozone, sulfur dioxide, particulate 

matter, and meteorology collected in NPS 

units by state agencies which supplement the 

data collected by the GPMP.

 State Programs

The NPS cooperates with a number of 

state agencies. At some sites, state air 

quality agencies provide measurement and 

operations support, and data are generally 

shared directly among cooperating agencies. 

Relevant O3, SO2, PM, and meteorological 

data submitted by states to the EPA AQS are 

retrieved for inclusion in this report. 

There are also numerous sites near park 

units operated by state or other agencies, 

independent of the NPS. Data from these 

sites are also retrieved from the EPA AQS for 

inclusion in this report, but are presented 

separately from data collected by state sites 

in cooperation with the NPS. 

Throughout this report, state-operated 

monitoring site names in tables and fi gures 

are indicated in italics.

The POMS are intended for 

short-term seasonal use at 

locations where reference 

method monitoring has not 

occurred or is not practical.

Network Description
 4

CASTNet 

Most GPMP stations operate 

cooperatively with the EPA Clean Air 

Status and Trends Network (CASTNet). 

Weekly integrated particulate samples are 

collected on fi lter packs at CASTNet sites. 

The samples are analyzed for ambient 

atmospheric nitrates, sulfates, ammonium, 

sulfur dioxide, and nitric acid, and the 

results are used to estimate atmospheric 

dry deposition. More information is 

available at the CASTNet Web site at

http://www.epa.gov/castnet.

IMPROVE 

The Interagency Monitoring of Protected 

Visual Environments (IMPROVE) is a 

consortium of federal and state agencies 

which conduct visibility monitoring in 

Class I areas, including national parks. A 

number of instruments are used to monitor 

visibility, including:

Aerosol samplers, which collect 24-

hour integrated particle samples every 

three days on a series of fi lter media. 

Filters are later analyzed for PM2.5 and 

PM10 mass, elements, ions, and carbon.

Transmissometers, which directly 

measure the atmospheric light 

extinction over a sight path of several 

kilometers.

Nephelometers, which perform point 

optical measurements of the scattering 

component of atmospheric light 

extinction.

•

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Cameras, which document the appearance 

of a scene as viewed through the 

atmosphere, are often collocated with 

IMPROVE stations. Digital images from 

many sites are posted to the Internet along 

with relevant air quality data and other 

information in near real-time for public 

viewing.

More information is available at the 

IMPROVE Web site at http://vista.cira.

colostate.edu/improve.

NADP/NTN and NADP/MDN

The National Atmospheric Deposition 

Program/National Trends Network (NADP/

NTN) includes wet deposition monitoring at 

over 250 sites nationwide. The NADP network 

has been collecting data for over 30 years, and 

is coordinated from the Program Offi ce at 

the Illinois State Water Survey in Champaign, 

Illinois. Data for all major ions are available 

in concentrations (mg/L) and depositions 

expressed by kilograms/hectare (kg/ha). The 

National Atmospheric Deposition Program/ 

Mercury Deposition Network (NADP/MDN) 

includes wet mercury deposition monitoring 

at over 90 sites nationwide. NADP sites 

are often collocated with the GPMP air 

quality monitoring stations. Data from these 

networks are not presented in this report. 

More information about both of these 

programs is available at the NADP Web site at

http://nadp.sws.uiuc.edu/.

•

Mount Rainier National Park, 

Washington

Air Quality Monitoring Station

Photo by Mike Slate/

Air Resource Specialists, Inc.
5

Figure 1. 2007 Air quality monitoring in or nearby park units.
 6

Table 1. 2007 Site specifi cations.

National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number

Latitude

(degrees 

west)

Longitude

(degrees 

north)

Elev.

(m)

O3

Yearsa SO2 WD WS TMP R

Sites operated by the National Park Service

Abraham Lincoln Birthplace Visitor’s Center KY ABLI-VC --- 21-123-1001 37.5314 85.7347 1212 2 --- X X X 

Agate Fossil Beds Residence Area NE AGFO-RA --- 31-165-1001 42.4283 103.7294 1344 1 --- X X X 

Assateague Island Maintenance Area MD ASIS-MA --- 24-047-1001 38.2511 75.1594 3 3 --- X X X 

Badlands Visitor Center SD BADL-VC --- 46-071-1001 43.7436 101.9414 739 11 X X X X 

Big Bend K-Bar Ranch Road TX BIBE-KB BBE401 48-043-0101 29.3022 103.1772 1052 18 --- X X X 

Canyonlands Island in the Sky UT CANY-IS CAN407 49-037-0101 38.4586 109.8211 1809 16 --- X X X

Carlsbad Caverns Maintenance Area NM CAVE-MA --- 35-015-3001 32.1783 104.4406 1349 2 --- X X X 

Chiricahua Entrance Station AZ CHIR-ES CHA467 04-003-8001 32.0092 109.3892 1570 17 --- X X X 

Colorado Maintenance Yard CO COLM-MY --- 08-077-1001 39.1067 108.7411 1740 2 --- X X X 

Craters of the Moon Visitor Center ID CRMO-VC --- 16-023-0101 43.4606 113.5622 1815 16 --- X X X 

Cumberland Gap Hensley Settlement KY CUHA-HS --- 21-013-1002 36.6719 83.5264 1013 2 --- X X X 

Death Valley Park Village CA DEVA-PV DEV412 06-027-0101 36.5092 116.8481 125 15 --- X X X 

Denali Headquarters AK DENA-HQ DEN417 02-290-0003 63.7258 148.9633 661 21 --- X X X 

Dinosaur West Entrance Housing UT DINO-WE --- 49-047-1002 40.4372 109.3047 1463 3 --- X X X 

Everglades Beard Center FL EVER-BC EVE419 12-086-0030 25.3911 80.6806 2 --- --- X X X 

Glacier West Glacier Horse Stables MT GLAC-WG GLR468 30-029-8001 48.5103 113.9956 976 16 --- X X X 

Grand Canyon The Abyss AZ GRCA-AS GRC474 04-005-8001 36.0597 112.1822 2073 15 --- X X X 

Great Basin Maintenance Yard NV GRBA-MY GRB411 32-033-0101 39.0053 114.2158 2060 15 --- X X X 

Great Smoky Mountains Clingmans Dome TN GRSM-CD --- 47-155-0102 35.5619 83.4981 2021 15 --- X X X 

Great Smoky Mountains Cove Mountain TN GRSM-CM --- 47-155-0101 35.6967 83.6086 1243 20 X X X X 

Great Smoky Mountains Look Rock TN GRSM-LR GRS420 47-009-0101 35.6331 83.9422 793 20 --- X X X 

Hawaii Volcanoes Observatory HI HAVO-OB --- 15-001-0007 19.4203 155.2881 1123 --- X X X X 

Hawaii Volcanoes Visitor Center HI HAVO-VC --- 15-001-0005 19.4308 155.2578 1215 --- X X X X 

Joshua Tree Black Rock CA JOTR-BR JOT403 06-071-9002 34.0714 116.3906 1244 15 --- X X X 

Joshua Tree Cottonwood Canyon CA JOTR-CC --- 06-065-0008 33.7411 115.8206 984 3 --- X X X 

Joshua Tree Pinto Wells CA JOTR-PW --- 06-065-1004 33.9397 115.4108 326 2 --- X X X 

Lassen Volcanic Manzanita Lake Fire Station CA LAVO-ML LAV410 06-089-3003 40.5403 121.5764 1756 21 --- X X X 

Mammoth Cave Houchin Meadow KY MACA-HM MAC426 21-061-0501 37.1317 86.1481 243 13 X X X X 

Mesa Verde Resource Management Area CO MEVE-RM MEV405 08-083-0101 37.1983 108.4903 2165 15 --- X X X

Mojave Kelso Mountains CA MOJA-KM --- 06-071-1001 35.1019 115.7767 1212 1 --- X X X 

Mount Rainier Tahoma Woods WA MORA-TW MOR409 53-053-1010 46.7583 122.1244 415 17 --- X X X 
7

Table 1. 2007 Site specifi cations (continued).

National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number

Latitude 

(degrees 

west)

Longitude 

(degrees 

north)

Elev.

(m)

O3

Yearsa SO2 WD WS TMP 

Sites operated by the National Park Service

Natchez Trace Parkway Dancy Ranger Station MS NATR-DR --- 28-155-1001 33.6636 89.0622 94 2 --- X X X 

North Cascades Marblemount Ranger Stn WA NOCA-MM NCS415 53-057-0013 48.5397 121.4472 109 12 --- X X X 

Olympic Hurricane Ridge Portable WA OLYM-HP --- 53-009-1004 47.9706 123.5028 1543 4 --- X X X 

Padre Island Malaquite Visitor Center TX PAIS-MV --- 48-273-1001 27.4267 97.2983 6 3 --- X X X 

Petrifi ed Forest South Entrance AZ PEFO-SE PET427 04-017-0119 34.8225 109.8919 1723 6 --- X X X

Pinnacles SW of East Entrance Station CA PINN-ES PIN414 06-069-0003 36.485 121.1556 335 21 --- X X X 

Rocky Mountain Long’s Peak CO ROMO-LP ROM406 08-069-0007 40.2778 105.5453 2743 23 --- X X X 

Sequoia and Kings Canyon Ash Mountain CA SEKI-AS SEK430 06-107-0009 36.4894 118.8269 457 9 --- X X X 

Sequoia and Kings Canyon Lower Kaweah CA SEKI-LK --- 06-107-0006 36.5658 118.7772 1890 24 --- X X X 

Shenandoah Big Meadows VA SHEN-BM SHN418 51-113-0003 38.5231 78.4347 1073 25 --- X X X 

Voyageurs Sullivan Bay MN VOYA-SB VOY413 27-137-0034 48.4128 92.8292 429 12 --- X X X 

Yellowstone Old Faithful WY YELL-OF --- 56-039-1012 44.4569 110.8314 2246 --- --- X X X 

Yellowstone Water Tank WY YELL-WT YEL408 56-039-1011 44.5597 110.4006 2400 12 --- X X X 

Yosemite School Yard CA YOSE-SY --- 06-043-1004 37.7477 119.5917 1234 2 --- X X X 

Yosemite Turtleback Dome CA YOSE-TD YOS404 06-043-0003 37.7061 119.7061 1605 15 --- X X X 

Zion Dalton’s Wash UT ZION-DW --- 49-053-0130 37.1983 113.1506 1213 4 --- X X X

 # active park units: 39 # active park sites: 47

Sites operated by cooperating state agencies

Acadia Cadillac Mountain ME ACAD-CM --- 23-009-0102 44.3472 68.2278 466 13 --- X X X 

Acadia McFarland Hill ME ACAD-MH ACA416 23-009-0103 44.3769 68.2608 158 10 --- X X X 

Cape Cod Cape Cod MA CACO-XX --- 25-001-0002 41.9758 70.0247 41 21 --- X X X 

Chamizal Chamizal TX CHAM-XX --- 48-141-0044 31.7656 106.455 1128 16 --- X X X 

Congaree Congaree Bluff SC COSW-BL --- 45-079-0021 33.8147 80.7811 34 8 X --- --- --- 

Cowpens State Monitor SC COWP-SM --- 45-021-0002 35.1303 81.8164 296 20 --- --- --- --- 

Great Smoky Mountains Cades Cove TN GRSM-CC --- 47-009-0102 35.6042 83.7831 564 15 --- X X X 

Great Smoky Mountains Purchase Knob NC GRSM-PK --- 37-087-0036 35.59 83.0775 1500 13 --- --- --- --- 

Mount Rainier Jackson Visitor’s Center WA MORA-JV --- 53-053-0012 46.7853 121.7378 1615 10 --- --- --- --- 

Saguaro Pima County AZ SAGU-PC --- 04-019-0021 32.1744 110.7364 938 16 --- X X X 

Theodore Roosevelt Painted Canyon Visitor Cntr ND THRO-VC THR422 38-007-0002 46.8947 103.3778 850 10 X X X X 

Wind Cave Visitor Center SD WICA-VC WNC429 46-033-0132 43.5578 103.4839 1292 4 X X X X 

Yosemite Village CA YOSE-VI --- 06-043-1001 37.7458 119.6028 1216 --- --- --- --- --- 

 # active park units: 11 # active park sites: 13
 8

Table 1. 2007 Site specifi cations (continued).

National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number

Latitude

(degrees 

west)

Longitude

(degrees 

north)

Elev.

(m)

O3 

Yearsa SO2 WD WS TMP R

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet Site TX ALCO-CA ALC188 --- 30.4211 94.4044 4 --- X X X 

Appalachian Trail Mount Greylock Summit MA APTR-MG --- 25-003-4002 42.6367 73.1686 1140 19 --- --- --- --- -

Blue Ridge Parkway 7510 Blue Ridge Parkway NC BLRI-75 --- 37-011-0002 35.9717 81.9342 987 9 --- --- --- X 

Blue Ridge Parkway Barnet Knob Firetower Road NC BLRI-BK --- 37-099-0005 35.5244 83.2361 1433 9 --- --- --- --- -

Blue Ridge Parkway Frying Pan Mountain NC BLRI-FP --- 37-087-0035 35.3792 82.7925 1585 14 --- --- --- --- -

Blue Ridge Parkway Route 191 NC BLRI-RO --- 37-021-0030 35.5 82.6 675 19 --- --- --- --- -

Blue Ridge Parkway Ranger Station VA BLRI-RS --- 51-163-0003 37.6261 79.5131 280 9 --- --- --- X 

Blue Ridge Parkway Vinton Elementary VA BLRI-VE --- 51-161-1004 37.2856 79.8842 346 27 X --- --- --- -

Boston Harbor Islands Former Nike Missile Site MA BOHA-NM --- 25-025-0041 42.3175 70.9689 10 10 --- X X X 

Cuyahoga Valley 800 Patterson OH CUVA-PA --- 39-153-0020 41.1061 81.5039 305 28 --- --- --- --- -

Everglades Cutler Road FL EVER-CR --- 12-086-0029 25.5861 80.3269 4 23 --- --- --- --- -

George Washington Pkwy Alexandria Health VA GEWA-AH --- 51-510-0009 38.8108 77.0447 23 39 X --- --- --- -

Guilford Courthouse Mendenhall Middle School NC GUCO-MM --- 37-081-0013 36.1092 79.8011 247 7 --- --- X X 

Indiana Dunes Ammunition Bunker IN INDU-AB --- 18-089-0022 41.5733 87.3047 183 15 X X X X 

Indiana Dunes Gas Station IN INDU-GS --- 18-091-0005 41.7169 86.9075 187 32 X X X X -

Indiana Dunes Water Treatment Plant IN INDU-WT --- 18-127-0024 41.6175 87.1992 183 25 --- --- --- --- -

Mississippi Anoka County Airport MN MISS-AC --- 27-003-1002 41.1397 93.2075 281 29 X --- --- --- -

Mississippi Somerset Town Hall WI MISS-ST --- 55-109-1002 45.1244 92.6625 278 41 --- X X --- -

Mississippi Washington County MN MISS-WC --- 27-163-6015 45.1189 92.855 0 11 --- --- --- --- -

Mount Baker Mount Baker WA MTBA-XX --- --- 48.8561 121.6817 1463 1 --- X X X 

Petroglyph Westside Taylor Ranch NM PETR-WT --- 35-001-0027 35.1519 106.6836 5111 9 --- --- --- --- -

Rock Creek Achbold Parkway DC ROCR-AP --- 11-001-0025 38.9753 77.0228 91 28 --- --- --- --- -
9

Table 1. 2007 Site specifi cations (continued).

National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number

Latitude 

(degrees 

west)

Longitude 

(degrees 

north)

Elev.

(m)

O3 

Yearsa SO2 WD WS TMP R

Nearby sites operated by other agencies

Saratoga Stillwater NY SARA-ST --- 36-091-0004 43.0122 73.6489 120 20 --- --- --- --- -

Saugus Iron Works Lynn Water Treatment MA SAIR-LW --- 25-009-2006 42.4744 70.9725 52 16 --- X X X 

 # active park units: 15 # active park sites: 24

a The values in this column represent the number of years an ozone analyzer has been operational at the site.

b A fi lter pack is a part of the CASTNet network and is used to measure dry deposition using the “inferential method.” This method combines air quality concentration data with meteorologica

compute deposition velocities. Ambient air is drawn across the fi lter at either 3.0 or 1.5 liters per minute. The fi lter is then analyzed in a lab to yield weekly average concentrations of particulate 

particulate ammonium (NH4+), sulfur dioxide (SO2), and nitric acid (HNO3). In some cases, the positive ions Na+, K+, Ca2+, and Mg2+ are also measured from the fi lter samples.

Operating agency key: plain text = site operated by the National Park Service italics = site operated by a state agency underline = site operated by the National Park Service, but consisting of non-EPA certifi ed portable instrumentation

Parameter key: O3 = ozone analyzer WD = vector wind direction TMP = ambient temperature RNF = precipitation DTP = delta temperatu

 SO2 = sulfur dioxide analyzer SWS = scalar wind speed RH = relative humidity WET = wetness SOL = solar radiation

Note: Dashed lines indicate parameter not measured at that site. 

11

Surface-level ozone, sulfur dioxide, and 

particulate matter are regulated under the 

Clean Air Act, the comprehensive federal 

law that regulates air quality in the United 

States. Among other things, the Clean Air 

Act requires the EPA to set standards for 

“criteria pollutants.” These standards, 

known as the National Ambient Air Quality 

Standards (NAAQS), defi ne the national 

targets for acceptable concentrations of 

each of the criteria pollutants. 

In 2007 the primary NAAQS for ozone 

was 0.08 ppm (85 ppb) equivalent) over 

an 8-hour period. An exceedance of the 

standard occurs when an 8-hour average 

ozone concentration is greater than or equal 

to 85 ppb. An exceedance of the standard 

is not the same as a violation. A violation 

occurs when the 3-year average of the fourth 

highest daily maximum 8-hour average 

ozone concentration equals or exceeds 85 

ppb. The secondary ozone standard defi ned 

by the EPA, which is supposed to protect 

the environment, is the same as the primary 

standard. In this report, ozone concentrations 

are compared to the NAAQS that was in place 

during the time period reported.

This section presents 2007 data summaries 

for the NPS GPMP. Ozone summaries for 

all sites are presented fi rst, followed by data 

summaries for sulfur dioxide, particulate 

matter, and meteorological parameters. In 

these data summary products, site names 

of EPA-certifi ed sites operated by the NPS 

are indicated with plain text, site names 

of EPA-certifi ed sites operated by state or 

other agencies are written in italics, and 

site names of portable ozone monitoring 

systems (POMS) operated by the NPS are 

underlined.

Throughout this report data summary tables 

are split according to each of these groups. 

Generally, four site groupings are provided 

in each table to compare data among sites 

that are operated in a similar manner.

Data Summaries

Pollutant

Ozone (O3) 

Sulfur Dioxide (SO2) 

Particulate Matter (PM2.5)

Particulate Matter (PM10)

Primary and Secondary 

NAAQS Standards During 2007

 0.08 ppm (84 ppb)

0.03 ppm (primary) (34 ppb)

0.14 ppm (primary) (144 ppb)

0.5 ppm (secondary) (549 ppb)

15.0 μg/m3

35 μg/m3

150 μg/m3

Averaging Time

 4th highest 8-hour average over 

3 years

annual arithmetic mean

daily arithmetic mean

3-hour average

annual arithmetic mean

98th percentile of the highest 

daily average over 3 years

daily arithmetic mean

http://www.epa.gov/air/criteria.html

Note: To convert from ppm to ppb, multiply by 1000.
 12

Ozone Data Summaries

Ground-level ozone, produced by the 

reaction of nitrogen oxides (NOx) and 

volatile organic compounds (VOCs) in the 

presence of sunlight, is one of the most 

widespread pollutants aff ecting vegetation 

and public health in the U.S. Although 

ozone is principally viewed as an urban 

problem, ozone and its precursor emissions 

can travel long distances, resulting in 

elevated ozone levels in national parks. 

Combustion processes from power plants, 

automobiles, and industries are the main 

anthropogenic emitters of NOx. Vehicles, 

industries, and natural vegetation emit 

VOCs.

Exposure to ozone aff ects human health, 

causing acute respiratory problems, 

aggravation of asthma, temporary 

decreases in lung capacity in some 

people, infl ammation of lung tissue, and 

impairment of the body’s immune system. 

Ozone also aff ects vegetation in national 

parks. 

To quantify ozone exposure to plants, 

various indices other than the primary and 

secondary standards are often used. These 

indices, described further on page 32, are 

believed to be biologically relevant because 

they take into account both peak ozone 

concentrations and cumulative exposure to 

ozone.

Annual Ozone Summaries

Table 2 summarizes O3 measurements with 

respect to the daily maximum 8-hour average 

concentrations at each NPS monitoring 

site. The fi ve highest daily maximum 8-hour 

average ozone concentrations are listed, as well 

as the total number of days with exceedances of 

the NAAQS 8-hour standard (8-hour average 

ozone values greater than or equal to 85 ppb). 

At each site with an EPA-certifi ed monitor, the 

fourth highest value column and the number of 

days column are both color-coded to identify 

sites where the fourth highest daily maximum 

8-hour average ozone value exceeded the 

8-hour standard during 2007. Note that other 

sites may have experienced fewer than four 

exceedances of the 8-hour standard, and are 

not color coded. Ozone summary statistics 

from POMS are highlighted bold where 

exceedances occurred. These sites should 

be compared to EPA standards for reference 

purposes only.

In 2007, six park units operated by the NPS 

and cooperating state agencies exceeded the 

8-hour standard, as compared to six sites in 

2006 (see Table 2). From 2006 to 2007, six of 

the NPS and cooperating state-operated park 

units had an increase in the number of days 

with an exceedance of the 8-hour standard 

and seven park units had a decrease.

The map in Figure 2 presents the annual 

fourth highest 8-hour average ozone 

concentrations for all network sites listed in 

Table 2. Ozone values for EPA-certifi ed sites 

are color-coded to represent values below 

(green) and above (orange and red) the 

national standard. Values from portable sites 

that exceed the standard are in bold but are 

not colored and are included for reference 

only.

The map in Figure 3 presents the annual 

number of days which exceeded the 8-hour 

standard for all network sites listed in Table 2. 

The data points are color-coded to distinguish 

between sites that did not exceed NAAQS 

(green) and those that did (orange and red). 

Data from portable sites (no color) are 

included for reference.

The map in Figure 4 presents the annual 

second highest 1-hour average ozone 

concentrations for all network sites. Ozone 

values for EPA-certifi ed sites are color-coded 

to represent four distinct levels. Ozone values 

from portable sites (no color) are included for 

reference only.

Research shows that some plants 

are more sensitive than humans 

to ozone and that effects on 

plants occur well below the EPA 

National Ambient Air Quality 

Standards (NAAQS).

Glacier National Park, Montana

Air Quality Monitoring Station

Photo by Martin Valvur/

Air Resource Specialists, Inc.
13

Table 2. 2007 Summary of 8-hour average ozone concentrations (ppb).

National Park Unit Site Name

Valid Number

of Days

1st

Highest

2nd

Highest

3rd 

Highest

4th 

Highesta

5th

Highest

# Days with 8-Hour 

Average O3 Values 

≥85 ppba

Sites operated by the National Park Service

Badlands Visitor Center 363 68 65 65 64 64 0

Big Bend K-Bar Ranch Road 355 72 72 71 68 67 0

Canyonlands Island in the Sky 339 74 74 73 72 71 0

Chiricahua Entrance Station 352 73 70 68 67 67 0

Craters of the Moon Visitor Center 220 71 68 67 67 65 0

Death Valley Park Village 351 94 91 91 85 85 6

Denali Headquarters 348 55 55 53 53 53 0

Glacier West Glacier Horse Stables 339 59 54 54 54 54 0

Grand Canyon The Abyss 352 72 70 70 69 69 0

Great Basin Maintenance Yard 348 82 80 78 75 75 0

Great Smoky Mountains Clingmans Dome 174 92 90 88 87 87 9

Great Smoky Mountains Cove Mountain 360 89 89 88 88 86 5

Great Smoky Mountains Look Rock 363 96 95 92 88 87 11

Joshua Tree Black Rock 341 106 105 104 104 103 40

Joshua Tree Cottonwood Canyon 281 82 78 76 76 75 0

Lassen Volcanic Manzanita Lake Fire Station 362 78 77 76 76 73 0

Mammoth Cave Houchin Meadow 359 84 84 83 82 82 0

Mesa Verde Resource Management Area 356 72 71 71 70 69 0

Mount Rainier Tahoma Woods 342 65 62 61 58 54 0

North Cascades Marblemount Ranger Stn 354 57 51 50 48 48 0

Petrifi ed Forest South Entrance 278 74 71 69 69 68 0

Pinnacles SW of East Entrance Station 361 83 77 76 75 74 0

Rocky Mountain Long’s Peak 335 79 79 78 78 77 0

Sequoia and Kings Canyon Ash Mountain 238 102 102 102 99 98 44

Sequoia and Kings Canyon Lower Kaweah 360 94 93 92 91 91 25

Shenandoah Big Meadows 339 75 75 74 73 73 0

Voyageurs Sullivan Bay 327 75 68 67 63 63 0

Yellowstone Water Tank 347 69 67 66 65 64 0

Yosemite Turtleback Dome 334 97 92 92 88 88 8

Zion Dalton’s Wash 305 77 77 71 71 70 0

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 186 98 94 89 86 85 5

Acadia McFarland Hill 300 92 85 83 83 82 2

Cape Cod Cape Cod 170 93 85 82 82 80 2

Chamizal Chamizal 359 78 77 77 75 73 0

Congaree Congaree Bluff 333 76 72 71 70 69 0

Cowpens State Monitor 358 74 68 67 67 67 0

Great Smoky Mountains Cades Cove 243 86 79 77 74 74 1

Great Smoky Mountains Purchase Knob 208 78 78 78 78 77 0

Mount Rainier Jackson’s Visitor’s Center 326 72 68 68 64 62 0

Saguaro Pima County 357 75 73 73 73 73 0

Theodore Roosevelt Painted Canyon Visitor Cntr 352 69 64 64 64 64 0

Wind Cave Visitor Center 363 75 71 69 69 68 0

85

88

87

88

104

11

40

99

91

88

86 5

6

5

9

25

44

8
 14

Table 2. 2007 Summary of 8-hour average ozone concentrations (ppb) (continued).

National Park Unit Site Name

Valid Number

of Days

1st 

Highest

2nd

Highest

3rd 

Highest

4th 

Highesta

5th

Highest

# Days with 8-Hour 

Average O3 Values 

≥85 ppba

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet Site 240 73 73 70 69 66 0

Appalachian Trail Mount Greylock Summit 143 93 86 83 80 79 2

Blue Ridge Parkway 7510 Blue Ridge Parkway 181 76 73 68 66 66 0

Blue Ridge Parkway Barnet Knob Firetower Road 200 84 83 80 80 77 0

Blue Ridge Parkway Frying Pan Mountain 193 90 84 78 77 77 1

Blue Ridge Parkway Route 191 213 77 77 73 73 72 0

Blue Ridge Parkway Ranger Station 205 73 70 66 65 65 0

Blue Ridge Parkway Vinton Elementary 182 86 79 77 76 76 1

Boston Harbor Islands Former Nike Missile Site 53 82 80 76 72 69 0

Cuyahoga Valley 800 Patterson 213 97 92 90 90 89 9

Everglades Cutler Road 357 75 75 74 71 69 0

George Washington Pkwy Alexandria Health 211 90 85 85 84 83 3

Guilford Courthouse Mendenhall Middle School 198 103 89 87 86 84 4

Indiana Dunes Ammunition Bunker 143 89 89 85 85 80 4

Indiana Dunes Gas Station 162 81 78 77 73 67 0

Indiana Dunes Water Treatment Plant 176 91 89 89 84 81 3

Mississippi Anoka County Airport 358 86 80 75 74 74 1

Mississippi Somerset Town Hall 358 79 78 78 75 73 0

Mississippi Washington County 176 79 79 79 77 71 0

Mount Baker Mount Baker 103 56 52 50 49 49 0

Petroglyph Westside Taylor Ranch 363 75 73 72 71 71 0

Rock Creek Achbold Parkway 350 87 87 85 84 83 3

Saratoga Stillwater 349 88 87 83 82 82 2

Saugus Iron Works Lynn Water Treatment 299 103 102 93 88 83 4

Portable ozone monitoring systems

Abraham Lincoln Birthplace Visitor Center 168 85 83 75 72 72 1

Agate Fossil Beds Residence Area 65 69 68 66 66 65 0

Assateague Island Maintenance Area 130 96 86 76 74 73 2

Carlsbad Caverns Maintenance Area 137 67 66 66 66 65 0

Colorado Maintenance Yard 150 67 67 67 67 67 0

Cumberland Gap Hensley Settlement 149 88 88 87 85 82 4

Dinosaur West Entrance Housing 163 68 64 63 63 63 0

Joshua Tree Pinto Wells 138 83 83 82 81 78 0

Mojave Kelso Mountains 118 101 91 89 88 87 6

Natchez Trace Parkway Dancy Ranger Station 184 73 73 70 70 69 0

Olympic Hurricane Ridge Portable 40 56 53 51 51 45 0

Padre Island Malaquite Visitor Center 161 80 78 75 75 72 0

Yosemite School Yard 195 72 67 66 66 66 0

a The primary and secondary National Ambient Air Quality Standard for ozone is 0.08 ppm over an 8-hour period. (An exceedance of the standard occurs when an 8-hour 

average ozone concentration is greater than or equal to 85 ppb. A violation of the standard occurs when the 3-year average of the fourth highest daily maximum 8-hour average 

ozone concentration equals or exceeds 85 ppb.) Exceedances of the standard are highlighted here in orange or red.

Note: The color coding break points follow the color categories used on the EPA’s AIRNow Web Site (http://www.airnow.gov). Dashed lines represent no data available at that site.

Operating agency key: plain text = site operated by the National Park Service italics = site operated by a state agency

 underline = site operated by the National Park Service, but consisting of non-EPA certifi ed portable instrumentation

Color shading key: 4th highest 8-hour average = 85 - 105 ppb ozone concentration # days with 8-hour average ≥85 ppb = 4 - 10 days

 > 105 ppb ozone concentration > 10 days

Note: On March 12, 2008, the EPA revised the ozone standard from 0.08 ppm to 75 ppb. 8-hour average ozone concentrations > 75 ppb will exceed the new ozone standard.

90

86 4

85 4

88

9

4
15

Figure 2. 2007 Annual fourth highest daily maximum 8-hour average ozone concentrations (in ppb).

Legend

0 - 84 ppbozone concentration

85 - 105 ppbozone concentration

> 105 ppbozone concentrationPortable site

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

Operating agency key:

plain text = site operated by the National Park Service

italics

underline

= site operated by other agencies

 = National Park Service operatedportable ozone system (POMS)

Great Smoky Mountains (5)

Abraham Lincoln Birthplace

Agate Fossil Beds

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado

Con

Cowpen

Craters of the Moon

Cumberland

 Gap

Denali

DeathValley

Dinosaur

Glacier

Great Basin

Grand Canyon

Joshua Tree (3)

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Baker

Mojave

Mount Rainier

Natchez Trace

Olympic North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (2) Shenandoah

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite (4)

Zion

Alabama-Coushatta

Appala

B

Blue Ridge Parkway (south unit) (4)

Cuyahoga 

Indiana Dunes (3)

Mississippi (3)

Petroglyph

72

66

64

68

72

66 75 67

67

70

67

67

85

53

85

63

54

75

69

88 104

76

82

70

88

64

70

48 51

75

69

75

78

73

99

73

64

63

69

65

88

71

69

76

80

90

86

85

77

71

49
 16

Figure 3. 2007 Annual number of days with daily maximum 8-hour average ozone values ≥85 ppb.

Abraham Lincoln Birthplace

Agate Fossil Beds

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado

Co

Cowpen

Craters of the Moon

Cumberland G

Denali

Death Valley

Dinosaur

Glacier

Great Basin

Grand Canyon

Great Smoky Mountains (5) Joshua Tree (3)

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Baker

Mojave

Mount Rainier

Natchez Trace

Olympic North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (2) Shenandoah

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite (4)

Zion

Alabama-Coushatta

App

B

Blue Ridge 

Cuyahoga 

Indiana Dunes (3)

Mississippi (3)

Petroglyph

655

1

0

0

0

0

0 0 0

0

0

0

0

4

0

6

0

0

0

0

11 40

0

0 0

0

5

0

0

0 0

0

0

0

0

0

44

0

0

0

0

8

0

0

1

1

9

4

4

1

0

Legend

0 - 3 days4 - 10 days

> 10 days

Portable site

Operating agency key:

plain text = site operated by the National Park Serviceitalics = site operated by other agencies

 = National Park Service operated underline portable ozone system (POMS)

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.
17

Figure 4. 2007 Annual second highest 1-hour average ozone concentrations (in ppb).

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

Operating agency key:

plain text = site operated by the National Park Service

italics = site operated by other agencies

underline = National Park Service operated

portable ozone system (POMS)

Legend

0 - 50 ppbozone concentration

51 - 100 ppbozone concentration101 - 150 ppbozone concentration

Portable site

>150 ppbozone concentration

Great Smoky Mountains (5)

Indiana Dunes (3)

Abraham Lincoln Birthplace

Agate Fossil Beds

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado

Cong

Cowpen

Craters of the Moon

Cumberland Gap

Denali

Death Valley

Dinosaur

Glacier

Great Basin

Grand Canyon

Joshua Tree (3)

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Baker

Mojave

Mount Rainier

Natchez Trace

Olympic North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (2)

Shenandoah

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite (4)

Zion

Alabama-Coushatta

Appalach

Bl

Blue Ridge Parkway (south unit) (4)

Cuyahoga 

Mississippi (3)

Petroglyph

Sar

98

76

72

77

79

71 101 74

73

84

82

80

92

56

105

77

63

84

78

115

122

82

91

76

105

78

83

63 57

86

79

95

89

83

114

84

75

79

81

74

98

81

82

94

96

105

9

107

89

87

102

55
 18

Ozone Violation Summaries

Table 3 presents ozone violation summaries 

for NPS-operated and cooperating sites for 

all 3-year periods over the last 10 years, with 

violations indicated in orange and red. For 

sites operating independently of the NPS, 

only the 2003-2005, 2004-2006, and 2005-

2007 violation summaries are presented. 

During the summarized period, a violation of 

the standard occurs when the 3-year average 

of the fourth highest daily maximum 8-hour 

average ozone concentration equals or 

exceeds 85 ppb. Table values in parentheses 

indicate that the EPA data completeness 

requirement for the 3-year period was not 

met. However, annual fourth highest daily 

maximum 8-hour ozone concentrations 

greater than or equal to 85 ppb for calendar 

years not meeting the EPA data completeness 

requirement are included in the NAAQS 

violation computation.

In 2007, fi ve of the NPS and cooperating 

state-operated sites within four national 

park units were in violation of the NAAQS 

8-hour standard, up from four sites within 

three units in 2006 (see Table 3). One site 

operated independently of the NPS recorded 

a violation in 2007.

Black Canyon of the Gunnison 

National Park, Colorado

Photo by Jessica Ward/

Air Resource Specialists, Inc.
19

Table 3. 2007 Ozone violation summary - primary standarda.

National Park Unit Site Name 2005 - 2007 2004 - 2006 2003 - 2005 2002 - 2004 2001 - 2003 2000 - 2002 1999 - 2001 1998 - 2000

Sites operated by the National Park Service

Badlands Visitor Center 68 67 (66) (64) (67) --- --- ---

Big Bend K-Bar Ranch Road 66 63 63 62 62 (62) (63) 66

Canyonlands Island in the Sky 69 69 71 72 70 (71) (71) 73

Chiricahua Entrance Station 71 72 71 70 69 69 70 70

Craters of the Moon Visitor Center (67) --- --- 67 (65) (63) (63) 66

Death Valley Park Village 84 82 81 80 81 81 79 80

Denali Headquarters 52 51 52 53 54 49 49 48

Glacier West Glacier Horse Stables 55 54 56 55 53 49 48 51

Grand Canyon The Abyss 72 73 74 74 74 73 72 73

Great Basin Maintenance Yard 73 72 72 72 70 72 72 73

Great Smoky Mountains Clingmans Dome (83) (80) (79) (87) (92) (98) (98) (102)

Great Smoky Mountains Cove Mountain 82 77 78 86 92 96 96 101

Great Smoky Mountains Look Rock 86 84 86 91 92 94 96 104

Joshua Tree Black Rock 103 103 105 106 99 94 92 102

Joshua Tree Cottonwood Canyon (66) (62) (45) --- --- --- --- ---

Lassen Volcanic Manzanita Lake Fire Station 72 69 68 71 72 74 77 78

Mammoth Cave Houchin Meadow 76 72 73 77 80 84 88 94

Mesa Verde Resource Management Area 73 73 70 68 67 69 69 70

Mount Rainier Tahoma Woods (56) (58) (61) 63 61 56 60 57

North Cascades Marblemount Ranger Stn (47) (48) (51) 51 50 46 48 46

Petrifi ed Forest South Entrance (70) (70) (71) (66) (64) (55) --- ---

Pinnacles SW of East Entrance Station 74 75 75 80 81 81 (79) (82)

Rocky Mountain Long’s Peak 75 74 77 82 81 78 74 77

Sequoia and Kings Canyon Ash Mountain (103) (103) (105) (105) (107) (105) (104) (105)

Sequoia and Kings Canyon Lower Kaweah 95 96 97 101 101 98 (94) (93)

Shenandoah Big Meadows 77 77 (80) 82 87 85 87 93

Voyageurs Sullivan Bay (65) 64 66 64 65 (64) 67 68

Yellowstone Water Tank 64 63 61 63 65 65 67 67

Yosemite Turtleback Dome 86 86 88 90 90 89 86 88

Zion Dalton’s Wash 79 80 (82) (74) --- --- --- ---

 # park units with violations:

 # sites with violations:

4

5

3

4

4

5

4

7

5

8

5

8

6

9

6

9

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 82 80 82 88 94 93 89 87

Acadia McFarland Hill 74 71 74 80 87 84 85 83

Cape Cod Cape Cod 84 84 86 88 95 93 96 89

Chamizal Chamizal 74 73 72 78 79 81 75 (79)

Congaree Congaree Bluff 71 71 71 74 77 77 (74) (73)

Cowpens State Monitor 73 74 75 80 84 87 87 92

Great Smoky Mountains Cades Cove 70 67 (67) 73 76 79 81 (85)

Great Smoky Mountains Purchase Knob 77 75 78 82 86 88 87 90

Mount Rainier Jackson Visitor’s Center 61 (60) (59) --- --- --- --- ---

Saguaro Pima County 76 76 (76) (75) (73) 72 69 (71)

Theodore Roosevelt Painted Canyon Visitor Cntr 63 60 59 60 61 59 58 (57)

Wind Cave Visitor Center 70 (71) (70) --- --- --- --- ---

 # park units with violations:

 # sites with violations:

0

0

0

0

1

1

2

2

3

4

4

4

4

5

4

5

103 103 105 106 99 94 92 102

91

86

(87)

92

92

(92)

94

96

(98)

96

96

(98) (102)

101

86 86 104

88 94

86 86 88 90 90 89 86 88

87 85 87 93

95 96 97 101 101 98 (94) (93)

(103) (103) (105) (105) (107) (105) (104) (105)

86

86

95

87

94

88

88

88

87

93

93

90

(85)

92

89

87

87

87

96

85

89
 20

Table 3. 2007 Ozone violation summary - primary standarda (continued).

National Park Unit Site Name 2005 - 2007 2004 - 2006 2003 - 2005 2002 - 2004 2001 - 2003 2000 - 2002 1999 - 2001 1998 - 2000

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet Site (70) (71) (72) --- --- --- --- ---

Appalachian Trail Mount Greylock Summit (81) (78) (80) --- --- --- --- ---

Blue Ridge Parkway 7510 Blue Ridge Parkway 69 69 71 --- --- --- --- ---

Blue Ridge Parkway Barnet Knob Firetower Road (76) (73) (72) --- --- --- --- ---

Blue Ridge Parkway Frying Pan Mountain 79 78 78 --- --- --- --- ---

Blue Ridge Parkway Route 191 74 74 74 --- --- --- --- ---

Blue Ridge Parkway Ranger Station 69 69 71 --- --- --- --- ---

Blue Ridge Parkway Vinton Elementary 76 74 74 --- --- --- --- ---

Boston Harbor Islands Former Nike Missile Site (79) 81 81 --- --- --- --- ---

Cuyahoga Valley 800 Patterson 85 81 85 --- --- --- --- ---

Everglades Cutler Road 69 68 66 --- --- --- --- ---

George Washington Pkwy Alexandria Health 83 81 81 --- --- --- --- ---

Guilford Courthouse Mendenhall Middle School (82) (81) (82) --- --- --- --- ---

Indiana Dunes Ammunition Bunker 82 75 76 --- --- --- --- ---

Indiana Dunes Gas Station 77 76 78 --- --- --- --- ---

Indiana Dunes Water Treatment Plant 81 76 78 --- --- --- --- ---

Mississippi Anoka County Airport 69 66 68 --- --- --- --- ---

Mississippi Somerset Town Hall 71 67 (69) --- --- --- --- ---

Mississippi Washington County (72) (67) (68) --- --- --- --- ---

Petroglyph Westside Taylor Ranch 72 71 72 --- --- --- --- ---

Rock Creek Achbold Parkway 81 80 78 --- --- --- --- ---

Saratoga Stillwater 79 77 82 --- --- --- --- ---

Saugus Iron Works Lynn Water Treatment 84 83 83 --- --- --- --- ---

 # park units with violations:

 # sites with violations:

1

1

0

0

1

1

0

0

0

0

0

0

0

0

0

0

a The primary and secondary National Ambient Air Quality Standard for ozone is 0.08 ppm over an 8-hour period. (An exceedance of the standard occurs when an 8-hour 

average ozone concentration is greater than or equal to 85 ppb. A violation of the standard occurs when the 3-year average of the fourth highest daily maximum 8-hour average 

ozone concentration equals or exceeds 85 ppb.) Exceedances of the standard are highlighted here in orange or red.

Note: The color coding break points follow the color categories used on the EPA’s AIRNow Web Site (http://www.airnow.gov).

Operating agency key: plain text = site operated by the National Park Service

 italics = site operated by a state agency

 underline = site operated by the National Park Service, but consisting of non-EPA certifi ed portable instrumentation

Color shading key: 4th highest 8-hour average 

 = 85 - 105 ppb ozone concentration 

 > 105 ppb ozone concentration 

Note: A number in parenthesis ( ) indicates that data completeness was not met. The primary standard requires 90 percent data completeness, on average, during the 3-year 

period, with no single year within the period having less than 75 percent data completeness. This data completeness requirement would have to be satisfi ed in order to determine 

that the standard has been met at a monitoring site. However, calendar years with less than 75 percent data completeness are included in the computation if the annual fourthhighest daily maximum 8-hour concentration is greater than the level of the standard. A site could be found not to have met the standard with less than complete data. 

Dashed lines represent no data available at that site. 

Note: On March 12, 2008, the EPA revised the ozone standard from 0.08 ppm to 75 ppb. In future years, 3-year average of the fourth highest daily maximum 8-hour average 

ozone concentrations greater than 75 ppb will violate the new ozone standard. 

85 85
21

Implications of the New National Ambient 

Air Quality Standard 

New Ozone Standard

On March 12, 2008, the EPA issued new, 

more stringent NAAQS for ozone by 

lowering the ozone standard from 84 

parts per billion (ppb) (0.08 ppm) to 75 

ppb (0.075 ppm) for both the primary and 

secondary standard1. The new standard 

is a signifi cant enhancement to protection 

of both human health and for vegetation 

and other natural resources. The primary 

standard is designed to better protect 

human health, and the secondary standard 

is intended to provide protection against 

“welfare” eff ects, including harm to native 

vegetation in protected areas1,2,3. By law, 

the EPA is required to base the NAAQS 

on science while providing an adequate 

margin for human safety. Economic issues 

related to the implementation of standards 

are not considered when determining 

NAAQS. 

Current Status

Many NPS units exceed the existing ozone 

NAAQS, prompting concerns for human 

health and vegetation. Aff ected parks issue 

health advisories to visitors and employees 

on high ozone days because ozone harms 

lung tissue and can cause respiratory 

problems. The new lower ozone standard 

will result in NAAQS exceedances at more 

parks. Also, there will be a greater number 

of days considered unhealthy in parks, and 

thus more health advisory alerts. 

Based on recent data, ozone 

concentrations in 11 parks operated 

by the NPS and state agencies violate 

the new standard. Data from the NPS 

portable stations and state monitoring 

near parks suggest another 73 sites have 

ozone concentrations that exceed the new 

standard. Rural counties without ozone 

monitoring may also exceed the standard. 

NPS interpolation mapping of ozone 

estimates that more than 150 park units 

may have concentrations that exceed the 

standard. How the EPA will structure rural 

monitoring and the specifi c requirements 

used to determine areas in violation are 

unknown at this point.

Ozone also aff ects vegetation. Visible plant 

injury and reduced growth from ozone 

have been documented in parks. Ozone 

can cause stress on entire ecosystems by 

reducing the ability of sensitive plant species 

and genotypes to adapt to or withstand 

environmental stresses, including freezing 

temperatures, pest infestations, or root 

disease. In addition, because it interferes 

with photosynthesis, ozone decreases the 

potential for carbon sequestration by plants. 

When revising the ozone standard the EPA 

did not adopt a separate secondary standard 

to protect “public welfare”2,3. 

Parks That May Violate the NAAQS Based 

on Measurements

In all past designations of non-attainment, 

EPA has required a minimum of 3 years’ 

of ozone data collected according to EPA 

monitoring regulations using certifi ed 

equivalent-method analyzers. Usually 

attainment status is determined at the 

county or metropolitan level based on 

monitors in those areas. Many natural 

areas and national parks are in rural areas 

and counties that do not have monitoring. 

Furthermore, when a park is in more than 

one county usually only the county with the 

direct monitoring data gets the designation 

status. Examples of this are Joshua Tree NP 

and Shenandoah NP where NPS monitoring 

showed a violation of the old NAAQS, 

but only the county in which the monitor 

was located received a non-attainment 

designation.

Table 4 lists the 11 parks that violate the 

new standard (greater than 75 ppb) based 

on direct monitoring in the parks. See 

Figure 5 for locations. Ozone concentrations 

from Rocky Mountain NP are right at the 

standard (75 ppb).

Table 4. Parks that violate the new ozone NAAQS for 

3-year average annual 4th highest 8-hour ozone (ppb).

Park Name

Park 

Code

2005-

2007

2004-

2006

Joshua Tree JOTR 103 103

Sequoia & Kings Canyon SEKI 103 103

Great Smoky Mountains GRSM 86 84

Yosemite YOSE 86 86

Cape Cod CACO 84 84

Death Valley DEVA 84 82

Acadia ACAD 82 80

Zion ZION 79 80

Shenandoah SHEN 77 77

Mammoth Cave MACA 76 72

Saguaro SAGU 76 76
 22

The parks in Table 5 have monitors that 

show ozone concentrations close to the 

new standard. Rocky Mountain NP and 

Chamizal are very close to the standard 

based on monitoring data.

POMS data indicate an additional eight parks 

with measured data that are very likely to 

violate the 75 ppb standard. POMS stations 

are temporary monitors that move after a few 

seasons and are intended only to provide a 

baseline measurement. The POMS stations 

in Table 6 have at least one year with a 4th

highest 8-hour ozone average greater than 

75 ppb. It is unlikely the EPA will designate 

an area as non-attainment based on these 

measurements since these monitors are not 

reference or equivalency methods. However, 

the data support arguments for reference 

or equivalency method monitoring in these 

areas.

Figure 5. Park units that will violate 

the new ozone NAAQS based on 

NPS monitoring network data.

Table 5. Parks with monitoring data that are close to 

the new NAAQS of 75 ppb.

Park Name

Park 

Code

4th Highest 8-Hour Ozone

2005-2007

3-year avg

2004-2006

3-year avg

Chamizal CHAM 74 73

Cowpens COWP 73 74

Rocky Mountain ROMO 75 74

Great Basin GRBA 73 72

Grand Canyon GRCA 72 73
23

Table 6. Portable ozone data (POMS) indicate several parks with high ozone (bold values exceed the standard).

POMS Network Annual 4th Highest 8-Hour Ozone Concentration (ppb)

Park Name

Park 

Code 3-year avg 2007 2006 2005 2004 2003

Black Canyon of the Gunnison BLCA 71 --- --- 68 80 67

Padre Island PAIS 75 75 80 71 --- ---

Assateague Island ASIS 78 74 84 72 --- ---

Lake Mead LAME 82 --- 81 84 80 77

Joshua Tree (eastern POMS site) JOTR --- 81 83 --- --- ---

Abraham Lincoln Birthplace ABLI --- 72 77 --- --- ---

Cumberland Gap CUGA --- 85 71 --- --- ---

Gulf Islands GUIS --- --- --- 74 78 ---

Mojave MOJA -- 88 --- --- --- ---

Source Park Counts Period

NPS monitored parks 11 2005-2007

POMS monitor data 8 1-3 seasons

Nearby monitors (SLAMS) 73 2005-2007

 92 parks potentially violate the new standard

Nearby monitors (within 5 miles of a 

park unit) have been found for a number 

of parks (Table 7). The 30 parks listed 

in Table 7 are projected to violate the 

new standard based on 2005-2007 data. 

If the park and the monitor are in the 

same county, then the violation may lead 

to designation of the county as nonattainment which would include the park. 

In total, 92 parks with direct data 

measurements are likely to violate the 

new NAAQS. This number is based on 

current and recent past data, not on future 

predictions from modeling or projected 

emission changes. Figures 5 and 6 display 

park units that exceed and may potentially 

violate the new ozone standard. 
 24

Table 7. NPS units within 5 miles of an ozone monitor and 2005-2007 average. 

Park Name

Park 

Code State

4th Highest 

8-Hour Ozone 

(2005-2007) Park Name

Park 

Code State

4th Highest 

8-Hour Ozone 

(2005-2007)

Martin Luther King, Jr. NHS MALU GA 89 Fredericksburg NC FRED VA 80

Fire Island NS FIIS NY 88 Jean Lafi tte NPres JELA LA 80

Chattahoochee River NRA CHAT GA 87 Adams NHS ADAM MA 80

Kennesaw Mountain NBP KEMO GA 87 Chickamauga and Chattanooga NMP CHCH TN 80

Gateway NRA GATE NY 86 Boston Harbor Islands NRA BOHA MA 80

Statue of Liberty NM STLI NJ 86 Boston African American NHS BOAF MA 80

General Grant NM GEGR NY 86 Boston NHP BOST MA 80

Hamilton Grange NMem HAGR NY 86 Frederick Law Olmsted NHS FRLA MA 80

Saint Paul’s Church NHS SAPA NY 85 John Fitzgerald Kennedy NHS JOFI MA 80

Hampton NHS HAMP MD 85 Longfellow NHS LONG MA 80

National Capital Parks - East NACE DC 85 Gulf Islands NS GUIS MS 80

National Capital Parks NRA NACA MD 85 James A. Garfi eld NHS JAGA OH 80

Ben Franklin NMem BEFR PA 85 Maggie L. Walker NHS MALW VA 80

Edgar Allan Poe NHS EDAL PA 85 Richmond NBP RICH VA 79

Gloria Dei (Old Swedes) Church NHS GLDE PA 85 Dayton Aviation Heritage NHP DAAV OH 79

Independence NHP INDE PA 85 Timpanogos Cave NM TICA UT 79

Thaddeus Kosciuszko NMem THKO PA 85 Fredericksburg & Spotsylvania NMP FRSP VA 79

John F. Kennedy Cntr for Performing Arts JOFK DC 84 Lake Mead NRA LAME NV 79

Lafayette Square P WHHO DC 84 First Ladies NHS FILA OH 79

National Mall & Memorial Parks NACC DC 84 Cuyahoga Valley NP CUVA OH 79

Rock Creek P ROCR DC 84 Saugus Iron Works NHS SAIR MA 79

Theodore Roosevelt NMem THIS VA 84 Lowell NHP LOWE MA 78

Arlington House Robert E. Lee ARHO VA 84 Little Rock Central High School NHS CHSC AR 78

Lyndon Baines Johnson NMem LYBA VA 84 Natchez NHP NATC MS 78

Clara Barton NHS CLBA MD 84 Guilford Courthouse NMP GUCO NC 78

George Washington Mem PKWY GWMP MD 84 Indiana Dunes NL INDU IN 78

Ulysses S. Grant NHS ULSG MO 84 Petersburg NB PETE VA 78

Jefferson National Expansion Mem NHS JEFF MO 83 Antietam NB ANTI MD 78

Wolf Trap Farm Park WOTR VA 83 Santa Monica Mountains NRA SAMO CA 77

Ocmulgee NM OCMU GA 82 Cumberland Gap NHP CUGA KY 76

New Bedford Whaling NHP NEBE MA 82 Tonto NM TONT AZ 76

Roger Williams NMem ROWI RI 82 Tupelo NB TUPE MS 76

William Howard Taft NHS WIHO OH 82 Allegheny Portage Railroad NHS ALPO PA 76

Prince William Forest Park PRWI VA 81 Big Thicket NPres BITH TX 76

Sleeping Bear Dunes NL SLBE MI 81 Blue Ridge Parkway BLRI VA 76

Monocacy NB MONO MD 81 Illinois & Michigan Canal NHC ILMI IL 75

Manassas NBP MANA VA 81

Notes:

- NPS units within 5 miles of ozone monitors used to compute 2005-2007 4th Highest 8-hour average

- Monitors used include ozone monitors and CASTNet monitors

- Ozone values are taken at park centroid - for parks with multiple units centroid of the largest unit was used
25

Figure 6. Counties and park units 

with monitoring data that support a 

possible violation of the new ozone 

NAAQS of 75 ppb. Only counties 

with NPS monitors or park units are 

shown. See Figure 9 for the urban 

counties EPA expects will violate the 

new standard.
 26

Estimates From GIS Interpolation 

The NPS Air Atlas project4 (http://www.

nature.nps.gov/air/maps/AirAtlas/index.

cfm) has taken data reported to the EPA 

AQS database plus Clean Air Status and 

Trends Network (CASTNet) data and 

interpolated the ozone values over the 

continental U.S. Although interpolated 

ozone values do not translate to a violation 

of the standard, this analysis does 

suggest a broader range of high ozone 

concentrations than direct monitoring 

alone indicates. In Figure 7, the yellow 

through the reds have 4th highest 8-hour 

ozone values of 75 ppb or greater for a 

three-year average. These are the areas 

Figure 7. Interpolations of 

monitoring data from the Air 

Atlas program. Yellow to red areas 

are projected to violate the new 

standard.

most likely to violate the new standard. On 

this map, the boundary of the 75 ppb and 

greater areas is only approximate.

Park units with interpolation zones that 

project possible violations of the ozone 

NAAQS are shown more clearly in Figure 8. 

Blue square symbols are park units within the 

violation zone and open squares are outside. 

Some parks are borderline or show locally 

monitored concentrations that confl ict with 

interpolations, such as Rocky Mountain 

NP, Pinnacles NM, and Acadia NP. Actual 

monitoring data will have to be used to 

resolve these confl icts.
27

Figure 8. Violation areas are 

extracted from the Figure 6 map and 

the parks in the violation areas are 

shown.

In its announcement of the new standard, 

the EPA provided a map and list of 

counties it expects to violate the new 

standard. Combining this information 

with the parks that are projected to violate 

the NAAQS based on monitoring and the 

parks in the >75 ppb O3 interpolation areas 

(Figure 8) another map can be generated 

based on counties (Figure 9). More than 

150 park units fall within counties that 

by measurement or interpolation might 

violate the new standard.

Since counties are designated nonattainment based on monitors within their 

boundaries, Figure 9 is an estimate of which 

counties and parks will be represented 

by monitors and which ones will not. If 

the counties become designated as nonattainment the parks would benefi t from 

clearer air associated with the control 

measures that might be implemented.

Counties Potentially in Violation

325 counties that could violate the standard according to interpolation intersect with a county containing 

an NPS unit.

141 NPS units in counties that could violate the standard according to interpolation of which counties 

have an ozone monitor (some counties have multiple park units).

1457 counties that could violate the standard according to interpolation of which counties do NOT have 

an ozone monitor.

•

•

•
 28

Figure 9. This map combines the 

counties EPA projects to violate 

the new standard (orange) and 

the counties projected from Air 

Atlas (rose color) as potentially in 

violation. The red, blue, and gray 

dots are park locations. Many rural 

counties have the potential to 

violate the standard. 
29

Figure 10. The counties highlighted 

in green have both park unit(s) 

and a monitor in the county (black 

dots) and are in areas that are 

potentially in violation according to 

interpolation.

EPA has proposed that each state should 

have at least two rural monitors, but a 

rule has not yet been promulgated. If EPA 

requires only two rural monitors in each 

state then very large areas that may exceed 

the 75 ppb standard will not be eff ectively 

covered. Current EPA plans (not formally 

announced or fi nal) are to use the rural 

CASTNet monitors as the foundation for 

rural monitoring. Most of the CASTNet 

stations in the Western states are NPS 

monitors. At least 22 states have fewer than 

two CASTNet rural monitors. The EPA 

network (http://www.epa.gov/ttn/amtic/

ncore/networks.html) with trace-leveling 

monitoring (NCORE) may fi ll in rural 

monitoring in some states. Many states 

also run rural monitors to get upwind or 

background concentrations to assist in 

pollutant modeling. Despite the planned 

rural monitoring coverage there will still 

be a large number of rural counties (and 

parks) with no monitoring data (Figure 10).

Frequency of Exceedances 

The standard doesn’t specifi cally address 

the number of days that exceed the standard 

and are therefore considered unhealthy air 

quality days. In many places the number 

of days that exceed the standard are many 

more than four per year. The frequency of 

exceedances per year, for locations where 

there is monitoring information, is given 

in Table 8 as an average number per year 

for the period 2005-2007. Five parks are 

highlighted that either already issue health 

warnings or might consider it because of 

the high number of exceedance days. In 

many cases, visibility and PM2.5 air quality 

is also quite poor during high ozone days. 

The combination of pollutants is more 

serious than when pollutants are considered 

separately and should be included in air 

quality advisories.
 30

Table 8. Frequency of exceedances (mean number of days) where the daily maximum 8-hour average was greater than 75 ppb based on 2005-2007 data. This 

mean is based on a simple count of the days. No annual completeness criteria (such as a minimum number of valid daily 8-hour maximums) were applied. 

Park Name Site Code

Park 

Code

Average 

Exceeds/

Year

Number 

of Years Park Name Site Code

Park 

Code

Average 

Exceeds/

Year

Number 

of Years

Abraham Lincoln Birthplace ABLI-VC ALBI 2 1 Indiana Dunes INDU-GS INDU 5 3

Acadia ACAD-CM ACAD 8 3 Indiana Dunes INDU-WT INDU 8 3

Acadia ACAD-MH ACAD 3 3 Isle Royale AQS Comparison Site #1 ISRO-X1 ISRO 0 3

Agate Fossil Beds AGFO-RA AGFO 0 1 Isle Royale AQS Comparison Site #2 ISRO-X2 ISRO 8 3

Appalachian Trail APTR-MG APTR 8 3 Joshua Tree JOTR-BR JOTR 68 3

Assateague Island ASIS-MA ASIS 3 1 Joshua Tree JOTR-CC JOTR 5 3

Badlands BADL-VC BADL 0 3 Joshua Tree JOTR-PW JOTR 6 1

Big Bend BIBE-KB BIBE 0 3 Lake Mead AQS Comp. Site #1 LAME-X1 LAME 6 3

Big South AQS Comparison Site BISO-XX BISO 2 3 Lake Mead AQS Comp. Site #2 LAME-X2 LAME 1 3

Blue Ridge Parkway BLRI-75 BLRI 1 3 Lassen Volcanic LAVO-ML LAVO 2 3

Blue Ridge Parkway BLRI-BK BLRI 5 3 Mammoth Cave MACA-HM MACA 6 3

Blue Ridge Parkway BLRI-BR BLRI 6 2 Mesa Verde MEVE-RM MEVE 2 3

Blue Ridge Parkway BLRI-FP BLRI 8 3 Mississippi MISS-AC MISS 1 3

Blue Ridge Parkway BLRI-RO BLRI 3 3 Mississippi MISS-ST MISS 2 3

Blue Ridge Parkway BLRI-RS BLRI 0 3 Mississippi MISS-WC MISS 2 3

Blue Ridge Parkway BLRI-VE BLRI 5 3 Mojave MOJA-KM MOJA 26 1

Boston Harbor Islands BOHA-NM BOHA 6 3 Mount Rainier MORA-JV MORA 0 3

Canyonlands CANY-IS CANY 0 3 Mount Rainier MORA-TW MORA 0 3

Cape Cod CACO-XX CACO 13 3 Natchez Trace NATR-DR NATR 0 1

Carlsbad Caverns CAVE-MA CAVE 0 1 North Cascades NOCA-MM NOCA 0 3

Chamizal CHAM-XX CHAM 4 3 Olympic OLYM-BL OLYM 0 1

Chiricahua CHIR-ES CHIR 0 3 Olympic OLYM-HP OLYM 0 1

Colorado COLM-MY COLM 0 1 Padre Island PAIS-MV PAIS 2 1

Congaree COSW-BL COSW 2 3 Petrifi ed Forest PEFO-SE PEFO 1 3

Cowpens COWP-SM COWP 4 3 Petroglyph PETR-WT PETR 1 3

Craters of the Moon CRMO-VC CRMO 0 3 Pinnacles PINN-ES PINN 4 3

Cumberland Gap CUGA-HS CUGA 16 1 Rock Creek ROCR-AP ROCR 10 3

Cuyahoga Valley CUVA-PA CUVA 16 3 Rocky Mountain ROMO-LP ROMO 4 3

Death Valley DEVA-PV DEVA 17 3 Saguaro SAGU-PU SAGU 4 3

Denali DENA-HQ DENA 0 3 Saratoga SARA-ST SARA 7 3

Dinosaur DINO-WE DINO 0 1 Saugus Iron Works SAIR-LW SAIR 10 3

Everglades EVER-CR EVER 1 3 Sequoia and Kings Canyon SEKI-AS SEKI 82 3

George Washington GEWA-AH GEWA 12 3 Sequoia and Kings Canyon SEKI-LK SEKI 63 3

Glacier GLAC-WG GLAC 0 3 Shenandoah SHEN-BM SHEN 5 3

Grand Canyon GRCA-AS GRCA 2 3 Theodore Roosevelt THRO-VC THRO 0 3

Great Basin GRBA-MY GRBA 2 3 Voyageurs VOYA-SB VOYA 1 3

Great Smoky Mountains GRSM-CC GRSM 1 3 Wind Cave WICA-VC WICA 1 3

Great Smoky Mountains GRSM-CD GRSM 21 3 Yellowstone YELL-WT YELL 0 3

Great Smoky Mountains GRSM-CM GRSM 18 3 Yosemite YOSE-M2 YOSE 0 1

Great Smoky Mountains GRSM-LR GRSM 26 3 Yosemite YOSE-MO YOSE 1 1

Great Smoky Mountains GRSM-PK GRSM 8 3 Yosemite YOSE-MR YOSE 0 1

Guilford Courthouse GUCO-MM GUCO 14 3 Yosemite YOSE-SY YOSE 0 1

Gulf Is. Port. AQS Comparison Site GUIS-XX GUIS 12 3 Yosemite YOSE-TD YOSE 23 3

Indiana Dunes INDU-AB INDU 7 3 Zion ZION-DW ZION 4 3
31

Severity of the NAAQS violation can be 

judged by both high concentrations of 

the 4th highest 8-hour values and by the 

number of exceedances per year. Parks can 

assess the severity based on frequency of 

exceedances during the summer season. 

Table 9 is a proposed scale that defi nes and 

categorizes violation severities. 

Timelines for Implementation of the New 

Standard 

The following is the EPA schedule for 

implementation of the new standard if the 

fi nal rule is not challenged and delayed by 

court action1. 

The Clean Air Act requires EPA to 

designate areas as attainment (meeting the 

standards), nonattainment (not meeting the 

standards), or unclassifi able (insuffi cient 

data to classify) after the Agency sets a new 

standard, or revises an existing standard. 

The following schedule will apply to the 

revised ozone standards: 

• States must make recommendations 

to EPA no later than March 2009 for 

areas to be designated attainment, 

nonattainment or unclassifi able. 

• EPA will issue fi nal designations of 

attainment, nonattainment and 

unclassifi able areas no later than 

March 2010, unless there is insuffi cient 

information to make these designation 

decisions. In that case, EPA will issue 

designations no later than March 2011. 

• States must submit State Implementation 

Plans outlining how they will reduce 

pollution to meet the standards by a date 

that EPA will establish in a separate rule. 

That date will be no later than three 

years after EPA’s fi nal designations. If 

EPA issues designations in 2010, then 

these plans would be due no later than 

2013. 

• States are required to meet the standards 

by deadlines that may vary based on the 

severity of the problem in the area. 

The years 2006 – 2008 will be the 3-year 

basis for designating non-attainment based 

on the new ozone standard. The current 

non-attainment areas will remain in eff ect 

and must progress towards attainment 

until new designations in 2010 and new 

plans in 2013. EPA modeling has projected 

that ozone concentrations will continue to 

decrease during that time. If that happens, 

then the number of locations that might 

violate the new standard, based on 2004-

2006 and 2007 data, may be an overestimate.

Conclusions 

The new ozone standard of 75 ppb is more 

protective and will result in signifi cantly 

more rural park units being included 

in the regulatory process for air quality 

improvement. Best information at this time 

indicates 92 parks have measured ozone 

concentrations that could put them in 

violation of the 75 ppb ozone NAAQS. There 

will be many more cultural and battlefi eld 

park units in urban areas classifi ed as nonattainment. Some of these, like Rock Creek 

in Washington DC, do have signifi cant 

natural resources. Potentially, more than 

150 parks highlighted in this analysis could 

violate the ozone standard. 

Many of the park units that would 

violate the new NAAQS are rural or in 

low population areas. Based on this, two 

challenges present themselves:

1. Notify visitors and staff of the ozone 

health risks.

2. Assure that all park units that violate the 

ozone standard actually get designated 

as non-attainment so that State 

Implementation Plans are revised to 

specifi cally address control measures to 

improve the ozone in these parks. 

Although current EPA rules specify that 

monitoring data must be used to designate a 

county non-attainment, for rural counties in 

the future, some combination of monitoring 

and modeling is more likely to be used, but 

is currently not specifi ed by the EPA. The 

secondary ozone standard has not been 

used much in the past since the primary 

and secondary standards have been the 

same values. At the new standard of 75 ppb 

many more rural and natural areas without 

signifi cant emission sources will have to be 

considered for non-attainment designation 

and some form of control strategies be 

implemented. 

Table 9. Ozone violation severity can also be judged by the frequency of events.

Number of exceedances per year Severity

 4 Borderline, likely to violate standard

 20 Serious, average of once per week

 50 30% of days unhealthy

> 75 > 50% of days unhealthy
 32

Resource Injury Indices

To quantify ozone exposure to plants, 

various indices other than the NAAQS 

primary and secondary standards are 

often used. These indices, defi ned below, 

take into account both peak ozone 

concentrations and cumulative exposure to 

ozone.

W126 – A cumulative index that is 

calculated as the maximum 3-month 

sum of the 0800-2000 hourly average 

ozone concentrations during the 

EPA-designated ozone season, where 

a weighting function is used to give 

increasing signifi cance (weights 

between 0 and 1) to concentrations of 

ozone greater than 0.04 ppm (40 ppb), 

and no weight to concentrations below 

0.04 ppm (40 ppb). Units of this index 

are ppm-hr. EPA considered using the 

W126 metric for the secondary standard 

in its recent review of the ozone 

NAAQS. In its technical review, EPA 

recognized that the W126 was a more 

biologically relevant measure of ozone 

exposure to plants. NPS supported a 

secondary standard of 7-9 ppm-hr.

SUM06 – A cumulative index that is 

calculated as the maximum 3-month 

sum of the 0800-2000 hourly average 

ozone concentrations during the ozone 

season that are equal to or greater than 

0.06 ppm (60 ppb). The units of this 

index are ppm-hr. Several thresholds 

have been developed for SUM06 (Heck 

and Cowling, 19975).

Table 10 displays the W126 and SUM06 

thresholds for ozone eff ects to vegetation. 

•

•

Table 11 presents the ozone exposure indices 

summary statistics for 2007. Summaries for 

POMS are included for reference only. Since 

portable sites are deployed for seasonal use, 

there may be signifi cant biases in W126 and 

SUM06 exposure indices calculated from 

their data. These statistics were not calculated 

for sites that were operational for less than 

three months during the year. In 2007 these 

sites were Agate Fossil Beds and Olympic. 

Figure 11 presents the 3-month maximum 

W126 exposure index. Figure 12 presents 

the annual 3-month maximum SUM06 

exposure index for all network sites listed 

in Table 11. Index values are color-coded to 

represent three distinct levels of cumulative 

exposure. Data from portable sites (no 

color) are included for reference only. 

Ozone eff ects depend not only on ozone 

exposure, but on other factors that may 

ameliorate or magnify the extent of ozone 

injury, including soil moisture, presence of 

other air pollutants, insects or diseases, and 

other environmental stresses. A high W126 

exposure in a drought year, for example, 

may not result in vegetation injury because 

stomatal closure to prevent moisture loss will 

also prevent ozone uptake.

In 2006, assessments were completed to 

evaluate the potential for ozone injury to 

vegetation at many national park service 

units. The assessments are available at

http://www.nature.nps.gov/air/pubs/

ecoeff ects.cfm. Information on ozonesensitive plant species is available at

http://www.nature.nps.gov/air/pubs/pdf/

baltfi nalreport1.pdf.

Table 10. W126 and SUM06 thresholds for ozone effects to vegetation (based on 3-month, 12-hour exposure)5

W126 SUM06

Growth Reduction

Tree seedlings - natural forest stands 7-13 ppm-hrs 10-15 ppm-hrs

Tree seedlings/saplings - plantations 9-14 ppm-hrs 12-16 ppm-hrs

Visible Foliar Injury

Plants in natural ecosystems 5-9 ppm-hrs 8-12 ppm-hrs
33

Table 11. 2007 Summary of indices for resource injury (W126 and SUM06).

National Park Unit Site Name

O3%

Valid

W126a

(ppm-hr)

SUM06b

(ppm-hr)

Sites operated by the National Park Service

Badlands Visitor Center 99.8 5.9 4.5

Big Bend K-Bar Ranch Road 98.8 17.5 17.3

Canyonlands Island in the Sky 97.2 27.9 33.0

Chiricahua Entrance Station 97.1 18.4 20.8

Craters of the Moon Visitor Center 60.4 14.7 10.7

Death Valley Park Village 97.3 51.4 80.0

Denali Headquarters 97.3 4.0 0.0

Glacier West Glacier Horse Stables 96.2 0.9 0.0

Grand Canyon The Abyss 97.6 32.7 48.4

Great Basin Maintenance Yard 96.6 27.8 34.3

Great Smoky Mountains Clingmans Dome 95.6 53.4 79.9

Great Smoky Mountains Cove Mountain 99.6 45.6 65.9

Great Smoky Mountains Look Rock 99.7 42.9 61.9

Joshua Tree Black Rock 95.5 88.2 119.0

Joshua Tree Cottonwood Canyon 77.0 30.0 41.1

Lassen Volcanic Manzanita Lake Fire Station 99.7 18.9 23.5

Mammoth Cave Houchin Meadow 99.3 25.1 35.0

Mesa Verde Resource Management Area 98.5 25.9 32.0

Mount Rainier Tahoma Woods 97.0 1.9 1.6

North Cascades Marblemount Ranger Station 98.7 1.2 0.2

Petrifi ed Forest South Entrance 86.6 19.9 25.3

Pinnacles SW of East Entrance Station 99.7 15.5 20.6

Rocky Mountain Long’s Peak 96.7 25.7 31.4

Sequoia and Kings Canyon Ash Mountain 69.0 75.5 111.2

Sequoia and Kings Canyon Lower Kaweah 99.6 75.6 102.2

Shenandoah Big Meadows 96.2 25.1 39.2

Voyageurs Sullivan Bay 94.9 7.8 5.3

Yellowstone Water Tank 96.7 13.7 11.9

Yosemite Turtleback Dome 96.6 44.4 67.0

Zion Dalton’s Wash 92.0 24.5 34.9

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 99.3 14.5 16.2

Acadia McFarland Hill 99.5 10.9 10.9

Cape Cod Cape Cod 94.1 17.4 20.6

Chamizal Chamizal 99.0 14.2 17.2

Congaree Congaree Bluff 93.0 10.1 13.3

Cowpens State Monitor 98.9 8.7 9.1

Great Smoky Mountains Cades Cove 99.2 15.5 22.2

Great Smoky Mountains Purchase Knob 94.4 26.9 36.6

Mount Rainier Jackson Visitor’s Center 86.9 4.6 3.9

Saguaro Pima County 98.4 19.9 24.5

Theodore Roosevelt Painted Canyon Visitor Center 96.8 5.9 3.4

Wind Cave Visitor Center 99.8 9.7 8.8
 34

Table 11. 2007 Summary of indices for resource injury (W126 and SUM06) (continued).

National Park Unit Site Name

O3%

Valid

W126a

(ppm-hr)

SUM06b

(ppm-hr)

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet site 65.9 3.8 2.9

Appalachian Trail Mount Greylock Summit 96.6 24.0 31.3

Blue Ridge Parkway 7510 Blue Ridge Parkway 89.8 10.5 13.8

Blue Ridge Parkway Barnet Knob Firetower Road 92.2 21.2 34.4

Blue Ridge Parkway Frying Pan Mountain 92.3 32.2 52.4

Blue Ridge Parkway Route 191 99.7 14.7 18.8

Blue Ridge Parkway Ranger Station 97.5 8.1 8.9

Blue Ridge Parkway Vinton Elementary 99.7 15.8 19.4

Boston Harbor Islands Former Nike Missile Site 29.2 3.2 2.1

Cuyahoga Valley 800 Patterson 99.8 23.9 31.5

Everglades Cutler Road 98.8 12.2 11.1

George Washington Pkwy Alexandria Health 100.0 19.0 24.0

Guilford Courthouse Mendenhall Middle School 92.8 25.9 37.1

Indiana Dunes Ammunition Bunker 91.2 13.4 17.2

Indiana Dunes Gas Station 90.5 6.2 6.2

Indiana Dunes Water Treatment Plant 97.1 14.9 19.9

Mississippi Anoka County Airport 99.2 9.6 10.9

Mississippi Somerset Town Hall 99.1 9.8 10.0

Mississippi Washington County 98.0 10.0 10.8

Mount Baker Mount Baker 94.4 0.9 0.0

Petroglyph Westside Taylor Ranch 99.7 18.5 25.4

Rock Creek Achbold Parkway 97.8 17.2 22.4

Saratoga Stillwater 98.6 13.1 15.0

Saugus Iron Works Lynn Water Treatment 97.5 12.0 13.7

Portable ozone monitoring systems

Abraham Lincoln Birthplace Visitor Center 98.4 12.1 14.8

Assateague Island Maintenance Area 90.5 15.5 20.0

Carlsbad Caverns Maintenance Area 82.7 11.0 9.0

Colorado Maintenance Yard 91.8 9.1 9.2

Cumberland Gap Hensley Settlement 99.3 37.8 52.1

Dinosaur West Entrance Housing 99.9 12.2 7.4

Joshua Tree Pinto Wells 94.6 33.6 51.1

Mojave Kelso Mountains 82.2 50.4 75.6

Natchez Trace Parkway Dancy Ranger Station 100.0 8.6 10.0

Padre Island Malaquite Visitor Center 88.6 13.4 19.6

Yosemite School Yard 98.2 7.3 6.1

a W126 exposure index represents 0800-2000 hourly ozone concentrations where each concentration is weighted by a function that gives greater emphasis to the higher hourly 

concentrations while still including the lower ones. The value reported here represents a three-month maximum value during the ozone season. Units are ppm-hr. For more 

information on the W126 exposure index go to http://www.nature.nps.gov/air/maps/AirAtlas/docs/air_quality_glossary.pdf.

b SUM06 exposure index represents the 0800-2000 hourly ozone concentrations equaling or exceeding 0.06 ppm. The value reported here represents a three-month maximum 

value during the ozone season. Units are ppm-hr.

Operating agency key: plain text = site operated by the National Park Service italics = site operated by a state agency

 underline = site operated by the National Park Service, but consisting of non-EPA certifi ed portable instrumentation
 3

5

Great Smoky Mountains (5)

Abraham Lincoln Birthplace

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado

Congar

Cowpens

Craters of the Moon

Cumberland Gap

Denali

DeathValley

Dinosaur

Glacier

Great Basin

Grand Canyon

Joshua Tree

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Baker

Mojave

Mount Rainier

Natchez Trace

North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/KingsCanyon (2)

Shenandoah

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite (4)

Zion

Alabama-Coushatta

Appalac

Blue R

Blue Ridge Parkway (south unit) (4)

Cuyahoga V

Gui

Indiana Dunes (3)

Mississippi (3)

Petroglyph

Sar

12.1

5.9

17.5

27.9

11.0 14.2 18.4

9.1

10.1

8.7

14.7

37.8

4.0

51.4

12.2

0.9

27.8

32.7

53.4

88.2

18.9

25.1

25.9

0.9

50.4

4.6

8.6

1.2

13.4

19.9

15.5

25.7

19.9

75.6

25.1

5.9

7.8

9.7

13.7

44.4

24.5

3.8

15.8

32.2

23.9

25.9

19

14.9

10.0

18.5

17.

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

Operating agency key:

plain text = site operated by the National Park Service

italics = site operated by other agencies

 = National Park Service operatedportable ozone system (POMS)

underline

Legend

0 - 7.9 ppm-hr8 - 12.9 ppm-

13 - 20.9 ppm-h

Portable site

>= 21 ppm-hr

Figure 11. 2007 3-month maximum W126 exposure index during the ozone season (0800-2000 hourly concentrations).
3

6Great Smoky Mountains (5)

Abraham Lincoln Birthplace

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado

Congar

Cowpens

Craters of the Moon

CumberlandGap

Denali

DeathValley

Dinosaur

Glacier

Great Basin

Grand Canyon

Joshua Tree

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Baker

Mojave

Mount Rainier

Natchez Trace

North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/KingsCanyon (2)

Shenandoah

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite (4)

Zion

Alabama-Coushatta

Appalachian 

B

Blue Ridge Parkway (south unit) (4)

Cuyahoga V

Indiana Dunes (3)

Mississippi (3)

Petroglyph

Sa

15

5

17

33

9 17 21

9

13

9

11

52

0

80

7

0

34

48

80

119

24

35

32

0

76

4

10

0

20

25

21

31

25

111

39

3

5

9

12

67

35

3

19

52

32

37

20

11

25

* Park units with more than one site are indicated with (x) following the parkunit name, where x represents the number of sites within the unit. At unitswhere more than one site exists, the highest value from all sites was reported.

Operating agency key:

plain text = site operated by the National Park Service

italics = site operated by other agencies

 = National Park Service operatedportable ozone system (POMS)

underline

Legend

0 - 7 ppm-hr8 - 16 ppm-h

> 16 ppm-hr

Portable site

Figure 12. 2007 3-month maximum SUM06 exposure index during the ozone season (0800-2000 hourly concentrations).
37

Sulfur Dioxide Data Summaries

Sulfur dioxide (SO2) is a criteria pollutant 

that over time undergoes chemical 

transformations in the atmosphere to 

form sulfur compounds, such as sulfuric 

acid and particulate sulfate, that can lead 

to environmental and health eff ects. Both 

sulfur dioxide and fi ne particulate sulfate 

can cause respiratory problems. Sulfur 

dioxide and acidic sulfate deposited on 

the earth’s surface can aff ect aquatic and 

terrestrial ecosystems. Sulfur compounds 

are a major constituent of acid rain and 

sulfate is one of the particulate species 

responsible for visibility degradation and 

regional haze.

The primary NAAQS for sulfur dioxide are 

an annual arithmetic mean of 0.03 ppm 

and a 24-hour mean of 0.14 ppm, not to 

be exceeded more than once per year. The 

secondary NAAQS is a 3-hour mean of 

0.50 ppm, not to be exceeded more than 

once per year. Table 12 summarizes sulfur 

dioxide measurements for comparison to 

these standards and lists the number of 

exceedances for each. Maximum hourly 

concentrations for each site are also 

presented in the table for reference. The SO2

at Hawaii Volcanoes National Park violates 

the SO2 NAAQS and is unhealthy. In 2007, it 

exceeded the 24-hour standard of 0.14 ppm 

nine times.

At Hawaii Volcanoes National Park, sulfur 

dioxide data are collected using a lower 

range and an upper range. The lower range 

does not capture values higher than 1 ppm 

(1,000 ppb), but is considered to be an 

EPA equivalency method. The upper range 

captures values above 1 ppm accurately, but 

is not an EPA equivalent range. The Hawaii 

Volcanoes National Park data presented in 

this report were collected using the upper 

range to give a more accurate representation 

of sulfur dioxide values.

Hawaii Volcanoes has an SO2 alert system to 

use current data to warn visitors and staff of 

developing unhealthy air quality conditions. 

A color code severity level is used to 

determine in-park actions using 15-minute 

average data. See the alert system Web site 

and associated links for more detail, at 

http://www.nature.nps.gov/air/WebCams/

parks/havoso2alert/havoalert.cfm.

Halema`uma`u plume, Hawaii,

just minutes after it turns from 

bright white to reddish-brown from 

ash and particulate matter

Photo by J. Kauahikaua
 38

Table 12. 2007 Summary of sulfur dioxide data.

National Park Unit Site Name

Annual

Arithmetic

Mean (ppb)a

Highest Daily 24-Hour

Average Concentrationb (ppb)

Highest Daily Maximum 3-Hour

Average Concentrationc (ppb)

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of Days

with 24-Hour 

Average

≥ 145 ppb

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of D

with 3-H

Maximu

≥ 550 p

Sites operated by the National Park Service

Great Smoky Mountains Cove Mountain 1 6666 0 21 19 13 13 0 

Hawaii Volcanoes * Observatory 18 222 221 217 217 9 879 830 698 585 5 

Hawaii Volcanoes * Visitor Center 14 187 168 163 163 6 1019 604 487 434 2 

Sites operated by cooperating state agencies

Badlands Visitor Center 1 2222 0 5433 0 

Congaree Congaree Bluff 1 10 8 7 7 0 41 38 32 30 0 

Theodore Roosevelt Painted Canyon Visitor Ctr 0 3 2 2 1 0 9 6 5 5 0 

Wind Cave Visitor Center 0 2111 0 4333 0 

Nearby sites operated by other agencies

Blue Ridge Parkway Vinton Elementary 3 9 9 8 8 0 25 21 20 20 0 

George Washington Pkwy Alexandria Health 3 12 12 11 10 0 48 33 33 32 0 

Indiana Dunes Ammunition Bunker 3 22 21 20 19 0 71 56 54 53 0 

Indiana Dunes Gas Station 2 15 10 9 9 0 27 23 22 20 0 

Mississippi Anoka County Airport 1 10 7 6 6 0 22 21 21 19 0 

a The primary annual National Ambient Air Quality Standard for sulfur dioxide is an annual arithmetic mean of 0.03 ppm. (A value greater than 0.03 ppm, 34 ppb, or 80 μg/m3 exceeds the sta

b The primary daily National Ambient Air Quality Standard for sulfur dioxide is 0.14 ppm over a 24-hour period not to be exceeded more than once per year. (A value greater than 0.14 ppm, 14

(40 CFR 50.4.)

c The secondary National Ambient Air Quality Standard for sulfur dioxide is 0.5 ppm over a 3-hour period not to be exceeded more than once per year. (A value greater than 0.5 ppm, 549 ppb

(40 CFR 50.5.)

* This site collected sulfur dioxide data using an instrument or a range that is not an EPA reference method.

Operating agency key: plain text = site operated by the National Park Service

italics = site operated by a state agency

Color shading key: >34 ppb annual arithmetic mean, >144 ppb 24-hour average, or >549 ppb 3-hour average

222 585

604

830 698

1019

879

163

217

163

217

168

221

187
39

Particulate Matter Data Summaries

Particulate matter (PM), is a complex 

mixture of extremely small particles and 

liquid droplets. Particle pollution is made 

up of a number of components, including 

acids (such as nitrates and sulfates), 

organic chemicals, metals, and soil or dust 

particles. Particles smaller than about 

10 micrometers in diameter (PM10) can 

enter the human respiratory system and 

cause health problems. Particles smaller 

than about 2.5 micrometers in diameter 

(PM2.5) are most signifi cantly tied to health 

concerns and, additionally, predominantly 

responsible for visibility degradation 

and regional haze. Particulate matter 

with nitrogen or sulfur species can lead 

to acid deposition or acid rain. Sources 

of particulate matter include: industrial 

activities, vehicle exhaust, fi res, vegetation, 

construction activities, wind-blown dust, 

and gaseous emissions which undergo 

chemical processes in the atmosphere to 

condense into particulate or liquid form.

The primary NAAQS for PM2.5 are an 

annual arithmetic mean of 15 μg/m3 and 

a daily arithmetic mean of 35 μg/m3. 

The daily arithmetic mean standard for 

PM2.5 changed from 65 μg/m3 to 35 μg/m3

in September 2006, and took eff ect on 

December 18, 2006. An exceedance of the 

standard occurs when either an annual 

arithmetic mean is greater than 15.0 μg/m3

or a daily arithmetic mean is greater than 

35 μg/m3. An exceedance of the standard 

is not the same as a violation. A violation 

occurs when either the 3-year average of 

the annual mean is greater than 15.0 μg/m3

or the 3-year average of the 98th percentile 

daily mean concentrations is greater than 

35 μg/m3.

The primary NAAQS for PM10 is a 

daily arithmetic mean of 150 μg/m3. An 

exceedance of the standard occurs when 

a daily arithmetic mean is greater than 

150 μg/m3. Again, an exceedance of the 

standard is not the same as a violation. A 

violation occurs when a 24-hour average 

concentration greater than 150 μg/m3 occurs 

more than once per year on average over 

three years. 

PM2.5 Data Summaries 

Table 13 summarizes PM2.5 measurements 

with respect to both the daily 24-hour 

average maximum concentrations and the 

annual arithmetic mean. None of the PM2.5

monitors at these sites are EPA-reference 

methods but rather are continuous analyzer 

methods EPA is considering for equivalency. 

The four highest and 98th percentile 24-hour 

average concentrations are listed, as well 

as the total number of days with 24-hour 

average PM2.5 concentrations greater than 

35μg/m3. No violation summaries for PM2.5

data are presented.
 40

Table 13. 2007 Summary of PM2.5 data from reference and equivalency methods.

National Park Unit Site Name

Sampler

Type*

%

Valida

Annual Arithmetic

Meanb (μg/m3)

Highest Daily 24-Hour Average Concentrationsc (μg/m3)

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

98th

Percentile

Value

No. of Days with 

24-Hour Average

>35 μg/m3

Sites operated by the National Park Service

Badlands Visitor Center BAM 99.2 4.0 27 25 18 18 12 0

Great Smoky Mountains Look Rock TEOM 99.1 15.8 97 86 49 44 40 12

Shenandoah Big Meadows TEOM 95.1 8.0 36 30 28 28 25 1

Yellowstone Old Faithful BAM 90.5 4.8 31 23 19 17 14 0

Sites operated by cooperating state agencies

Acadia McFarland Hill TEOM 91.2 3.8 37 29 25 25 22 1

Theodore Roosevelt Painted Canyon Visitor Ctr TEOM 96.5 6.0 24 21 19 18 15 0

Wind Cave Visitor Center BAM 94.5 3.8 28 27 25 18 13 0

Yosemite Village BAM 94.7 13.8 134 47 45 38 32 4

Nearby sites operated by other agencies

Guilford Courthouse Mendenhall Middle School TEOM 92.3 14.3 49 37 36 36 35 4

Indiana Dunes Ammunition Bunker TEOM 98.9 13.0 36 35 35 35 32 1

Indiana Dunes Water Treatment Plant BAM 98.9 14.0 51 38 33 31 38 2

Mississippi Anoka County Airport BAM 99.1 10.3 51 47 45 45 28 4

Petroglyph Westside Taylor Ranch BAM 73.6 6.0 37 25 22 20 19 1

Saugus Iron Works Lynn Water Treatment BAM 99.3 10.5 56 38 37 35 29 3

a At sites operated by an agency other than the National Park Service, the primary responsibility for the operation and data reporting of particulate matter belongs to the 

operating agency.

b The primary annual National Ambient Air Quality Standard for PM2.5 is an annual arithmetic mean of 15.0 μg/m3. (An exceedance of the standard occurs when an annual 

arithmetic mean of PM2.5 concentrations is greater than 15.0 μg/m3. A violation of the standard occurs when the 3-year average of the weighted annual mean PM2.5

concentrations is greater than 15.0 μg/m3 (40 CFR 50.7.)

c The primary daily National Ambient Air Quality Standard for PM2.5 is a 24-hour average concentration of 35 μg/m3. (An exceedance of the standard occurs when a 24-hour 

average PM2.5 concentration is greater than 35 μg/m3. A violation of the standard occurs when the 3-year average of the annual 98th percentile of 24-hour PM2.5 concentrations 

is greater than 35 μg/m3.) (40 CFR 50.7.)

* TEOM = tapered element oscillating microbalance

 BAM = beta attenuation monitor 
41

PM10 Data Summaries

Table 14 summarizes PM10 measurements 

with respect to both the daily 24-hour 

average maximum concentrations. 

The four highest 24-hour average 

concentrations are listed, as well as the 

total number of days with exceedances of 

the NAAQS 24-hour standard. The number 

of days column is color-coded to identify 

sites where an exceedance of the 24-hour 

standard occurred.

Table 15 presents the same summaries 

for sites that collected PM10 using nonequivalency methods.

Table 16 presents a PM10 violation summary 

based on the 24-hour average standard for 

one-year periods over the last three years, 

with violations indicated in red. Table values 

in parentheses indicate that the EPA data 

completeness requirement was not met. 

However, calendar quarters not meeting 

the EPA data completeness requirements 

are included in the NAAQS violation 

computation if the resulting 24-hour average 

exceeds the standard.

Bryce Canyon National Park,

Utah

Photo by Laura Weber/

Air Resource Specialists, Inc.
 42

Table 14. 2007 Summary of PM10 data from reference and equivalency methods.

National Park Unit Site Name

Sampler

Type*

%

Valida

Highest Daily 24-Hour Average Concentrationsb (μg/m3)

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of Days with 

24-Hour Average

>150 μg/m3

Sites operated by cooperating state agencies

Badlands Visitor Center BAM 95.9 50 40 40 40 0

Wind Cave Visitor Center BAM 97.4 40 40 40 40 0

a At sites operated by an agency other than the National Park Service, the primary responsibility for the operation and data reporting of particulate matter belongs to the 

operating agency.

b The primary daily National Ambient Air Quality Standard for PM10 is a 24-hour average concentration of 150 μg/m3. (An exceedance of the standard occurs when a 24-hour 

average PM10 concentration is greater than 150 μg/m3. A violation of the standard occurs when a 24-hour average concentration greater than 150 μg/m3 occurs more than once 

in a calendar year.) (40 CFR 50.6.)

* TEOM = tapered element oscillating microbalance

 BAM = beta attenuation monitor 

Color shading key: >50 μg/m3 annual arithmetic mean, >150 μg/m3 24-hour average

italics = site operated by a state agency 

Table 15. 2007 Summary of PM10 data from non-equivalency methods.

National Park Unit Site Name

Sampler

Type

%

Valida

Highest Daily 24-Hour Average Concentrationsb (μg/m3)

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of Days with 

24-Hour Average

>150 μg/m3

Sites operated by the National Park Service

Joshua Tree Cottonwood Canyon E-sampler 69.0 30 20 10 10 0

a At sites operated by an agency other than the National Park Service, the primary responsibility for the operation and data reporting of particulate matter belongs to the 

operating agency.

b The primary daily National Ambient Air Quality Standard for PM10 is a 24-hour average concentration of 150 μg/m3. (An exceedance of the standard occurs when a 24-hour 

average PM10 concentration is greater than 150 μg/m3. A violation of the standard occurs when a 24-hour average concentration greater than 150 μg/m3 occurs more than once 

in a calendar year.) (40 CFR 50.6.)

Color shading key: >50 μg/m3 annual arithmetic mean, >150 μg/m3 24-hour average

 

Table 16. PM10 summary - maximum daily 24-hour average concentration in 2007 (μg/m3)a.

National Park Unit Site Name Sampler Type* 2006 2005 2004

Sites operated by cooperating state agencies

Badlands Visitor Center BAM 50 30 40

Wind Cave Visitor Center BAM 40 30 30

a The primary daily National Ambient Air Quality Standard for PM10 is a 24-hour average concentration of 150 μg/m3. (An exceedance of the standard occurs when a 24-hour 

average PM10 concentration is greater than 150 μg/m3. A violation of the standard occurs when a 24-hour average concentration greater than 150 μg/m3 occurs more than once 

in a calendar year.) (40 CFR 50.6.)

* TEOM = tapered element oscillating microbalance

 BAM = beta attenuation monitor 

Color shading key: > 1 24-hour average concentration >150 μg/m3

italics = site operated by a state agency

 
43

Meteorological Data Summaries

Meteorological data collected along with 

air quality parameters are used to better 

understand the local conditions and 

transport of air pollutants. In addition, 

meteorological data are essential for air 

quality deposition modeling eff orts. Refer 

to Table 1 for a list of meteorological 

parameters collected at each site.

Wind Cave National Park,

South Dakota

Meteorological Instrumentation

Photo by Martin Valvur/

Air Resource Specialists, Inc.

Table 17 presents a summary of selected 

meteorological data for all sites. The 

parameters included are wind speed, 

ambient temperature, relative humidity, and 

precipitation.
 44

Table 17. 2007 Summary of selected meteorological data.

National Park Unit Site Name

Wind Speed 

(Scalara)

(m/s)

Ambient Temperature

(degrees C)

Relative Humidity

(%)

Precipitation

(mm)

Average Average Maximum Minimum Average Maximum Minimum

Annual 

Accumulation

Sites operated by the National Park Service

Badlands Visitor Center 4.0 10.9 41.7 -28.4 57 100 6 54.0

Big Bend K-Bar Ranch Road 3.5 19.5 38.4 -4.7 48 99 3 252.0

Canyonlands Island in the Sky 2.8 11.7 34.9 -14.3 38 100 0 217.7

Chiricahua Entrance Station 2.9 15.6 36.4 -8.5 44 100 6 451.4

Craters of the Moon Visitor Center 3.4 7.3 35.2 -22.2 52 100 7 ---

Death Valley Park Village 3.9 26.3 49.8 1.1 16 95 1 42.8

Denali Headquarters 1.3 -1.1 24.7 -32.6 68 99 17 206.7

Everglades Beard Center 2.3 23.3 34.2 0.5 84 100 29 1513.1

Glacier West Glacier Horse Stables 0.9 6.4 35.8 -28.6 70 99 10 603.6

Grand Canyon The Abyss 2.8 11.7 33.0 -15.5 38 100 2 289.2

Great Basin Maintenance Yard 2.8 9.8 33.5 -22.4 39 98 2 214.7

Great Smoky Mountains Clingmans Dome 3.5 13.1 22.9 -1.4 81 100 1 685.7

Great Smoky Mountains Cove Mountain 4.5 11.8 29.8 -18.0 68 100 5 608.1

Great Smoky Mountains Look Rock 2.5 14.1 32.4 -14.8 65 100 10 911.6

Hawaii Volcanoes Observatory 5.2 16.0 27.1 9.6 87 100 7 2051.2

Hawaii Volcanoes Visitor Center 3.8 14.9 23.7 8.0 91 100 11 2829.1

Joshua Tree Black Rock 4.0 16.7 39.4 -8.5 29 96 2 47.5

Joshua Tree Cottonwood Canyon 3.7 19.7 40.0 -4.3 27 100 3 100.1

Lassen Volcanic Manzanita Lake Fire Station 2.0 7.2 30.5 -14.4 59 100 6 640.7

Mammoth Cave Houchin Meadow 1.7 15.3 39.7 -13.2 66 100 19 1159.8

Mesa Verde Resource Management Area 3.0 10.7 32.3 -15.2 43 97 5 361.7

Mount Rainier Tahoma Woods 1.0 8.5 32.9 -10.1 86 100 16 1297.7

North Cascades Marblemount Ranger Station 1.2 9.1 36.2 -9.4 81 97 11 1965.4

Petrifi ed Forest South Entrance 4.0 13.1 36.3 -13.4 43 100 3 256.8

Pinnacles SW of East Entrance Station 2.3 14.1 41.1 -9.6 58 97 5 145.4

Rocky Mountain Long’s Peak 2.7 4.5 25.1 -24.5 51 97 4 272.2

Sequoia and Kings Canyon Ash Mountain 2.6 16.9 41.3 -3.4 50 100 8 423.5

Sequoia and Kings Canyon Lower Kaweah 1.7 9.4 30.5 -14.0 57 100 4 383.0

Shenandoah Big Meadows 2.6 1.9 21.2 -21.4 71 99 11 930.5

Voyageurs Sullivan Bay 2.7 4.5 34.9 -33.7 70 100 17 628.7

Yellowstone Old Faithful 1.7 3.2 31.0 -38.5 66 100 9 ---

Yellowstone Water Tank 1.7 2.1 28.2 -32.3 64 98 9 439.6

Yosemite Turtleback Dome 4.0 11.5 33.1 -10.9 47 99 5 294.3

Zion Dalton’s Wash 2.9 17.2 41.7 -11.9 31 100 3 179.4

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 5.9 13.5 29.8 -1.9 78 100 17 ---

Acadia McFarland Hill 3.0 7.3 33.9 -22.2 71 100 13 1202.2

Cape Cod Cape Cod 2.5 9.8 32.9 -14.2 69 92 14 ---

Chamizal Chamizal 3.3 19.2 39.8 -3.6 37 97 5 ---

Great Smoky Mountains Cades Cove 1.3 14.2 34.9 -12.9 72 100 13 866.8

Saguaro Pima County --- 21.7 42.1 -4.0 34 98 5 ---

Theodore Roosevelt Painted Canyon Visitor Center 5.3 6.3 39.7 -26.4 63 100 11 239.0

Wind Cave Visitor Center 3.2 8.4 35.9 -24.7 51 100 8 316.4
45

Table 17. 2007 Summary of selected meteorological data (continued).

National Park Unit Site Name

Wind Speed 

(Scalara)

(m/s)

Ambient Temperature

(degrees C)

Relative Humidity

(%)

Precipitation

(mm)

Average Average Maximum Minimum Average Maximum Minimum

Annual 

Accumulation

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet Site 1.9 19.6 36.8 -4.9 78 99 16 1290.3

Blue Ridge Parkway 7510 Blue Ridge Parkway --- 10.8 32.7 -15.3 76 100 12 ---

Blue Ridge Parkway Ranger Station --- 12.6 37.3 -15.7 67 99 7 ---

Boston Harbor Islands Former Nike Missile Site 2.9 10.5 35.9 -15.1 72 100 16 ---

Guilford Courthouse Mendenhall Middle School 0.9 17.4 37.7 -7.2 61 91 2 689.5

Indiana Dunes Ammunition Bunker 3.5 10.9 34.6 -22.6 70 97 16 ---

Indiana Dunes Gas Station 3.5 11.0 33.5 -20.0 --- --- --- ---

Mississippi Somerset Town Hall 2.6 --- --- --- --- --- --- ---

Mount Baker Mount Baker 1.9 9.9 26.7 -1.6 79 100 21 509.3

Saugus Iron Works Lynn Water Treatment 2.6 9.8 35.9 -17.1 60 90 3 35.5

Portable ozone monitoring systems

Abraham Lincoln Birthplace Visitor Center 0.5 22.7 39.4 1.9 69 99 21 428.8

Agate Fossil Beds Residence Area 3.3 20.0 38.7 -3.9 57 100 9 34.2

Assateague Island Maintenance Area 1.5 22.3 37.5 7.2 75 100 25 186.3

Carlsbad Caverns Maintenance Area 4.0 22.9 38.1 9.2 54 98 8 411.7

Colorado Maintenance Yard 1.8 22.1 37.1 1.3 31 100 3 103.1

Cumberland Gap Hensley Settlement 2.0 19.8 30.2 4.2 70 100 16 132.5

Dinosaur West Entrance Housing 1.4 21.7 38.9 1.6 37 97 5 85.2

Joshua Tree Pinto Wells 3.3 31.9 47.4 14.1 20 94 2 13.7

Mojave Kelso Mountains 3.4 26.5 40.0 8.5 22 100 4 75.5

Natchez Trace Parkway Dancy Ranger Station 0.3 23.1 40.1 -1.7 75 98 20 283.2

Olympic Hurricane Ridge Portable 0.7 10.0 26.4 -0.5 77 100 7 106.1

Padre Island Malaquite Visitor Center 5.7 26.4 32.5 5.7 82 100 39 520.1

Yosemite School Yard 0.8 16.4 37.8 -3.6 51 96 8 140.1

a Saguaro reports wind speed as vector wind speed rather than scalar wind speed.

Note: Dashed lines represent no data available for that particular parameter at that site.

Operating agency key: plain text = site operated by the National Park Service

 italics = site operated by a state agency

 underline = site operated by the National Park Service, but consisting of non-EPA certifi ed portable instrumentation
 46

References

1 EPA Final Rule on Revision to the 

National Ambient Air Quality Standard 

for ozone, March 12, 2008. http://www.

epa.gov/groundlevelozone/actions.

html#mar07s 

2 Proposed Rule; National Ambient Air 

Quality Standards for Ozone, 40 CFR 

Part 50, July 11, 2007. http://www.epa.

gov/groundlevelozone/pdfs/20070711_

proposal_fr.pdf 

3 Review of the National Ambient Air 

Quality Standards for Ozone: Policy 

Assessment of Scientifi c and Technical 

Information OAQPS Staff Paper, EPA452/R-07-007 July 2007. http://epa.gov/

ttn/naaqs/standards/ozone/data/2007_

07_ozone_staff _paper.pdf

4 NPS Air Atlas of Air Quality, Air 

Resources Division. http://www.

nature.nps.gov/air/maps/AirAtlas/index.

cfm 

5 Heck, W.W. and E.B. Cowling. 1997. The 

 Need for a Long-Term Cumulative 

 Secondary Ozone Standard – An 

 Ecological Perspective. Environmental 

 Management. January.
Data quality tables associated with the data presented in this report can be found at 

http://ard-request.air-resource.com. Click “Get Reports.”

The Department of the Interior protects and manages the nation’s natural resources and cultural 

heritage; provides scientifi c and other information about those resources; and honors its special 

responsibilities to American Indians, Alaska Natives, and affi liated Island Communities. 

NPS D-2017, October 2008
 EXPERIENCE YOUR AMERICATM

 Natural Resource Program Center

 Air Resources Division

P.O. Box 25287

 Denver, CO 80225

 www.nature.nps.gov/air

 National Park Service

 U.S. Department of the Interior

 Natural Resource Program Center