Annual Data Summary 2006

 Gaseous Pollutant Monitoring Program

 Ozone, Sulfur Dioxide, Particulate Matter, 

 Meteorological Observations

 Natural Resource Technical Report NPS ARD/NRPC/NRTR-2007/058

 National Park Service

 U.S. Department of the Interior

 Natural Resource Program Center

 Air Resources Division
ON THE COVER

Arches National Park, Utah

Photograph by Debbie Miller/NPS
Annual Data Summary 2006

Gaseous Pollutant Monitoring Program

Ozone, Sulfur Dioxide, Particulate Matter, 

Meteorological Observations

Natural Resource Technical Report NPS ARD/NRPC/NRTR-2007/058

John D. Ray, Ph.D.

National Park Service Air Resources Division, Gaseous Pollutant Monitoring Program

P.O. Box 25287

Denver, CO 80225-0287

October 2007

U.S. Department of the Interior

National Park Service

Natural Resource Program Center

Air Resources Division

Denver, Colorado
 ii 

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

broad readership in the National Park Service and to others in the management of natural resources, including the 

scientifi c community, the public, and the NPS conservation and environmental constituencies. Manuscripts are peerreviewed to ensure that the information is scientifi cally credible, technically accurate, appropriately written for the 

intended audience, and is designed and published in a professional manner.

The Natural Resource Technical Report series is used to disseminate the peer-reviewed results of scientifi c studies in 

the physical, biological, and social sciences for both the advancement of science and the achievement of the National 

Park Service’s mission. The reports provide contributors with a forum for displaying comprehensive data that are often 

deleted from journals because of page limitations. Current examples of such reports include the results of research 

that addresses natural resource management issues; natural resource inventory and monitoring activities; resource 

assessment reports; scientifi c literature reviews; and peer-reviewed proceedings of technical workshops, conferences, 

or symposia.

Views and conclusions in this report are solely those of the author and do not necessarily refl ect views and policies 

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.

Printed copies of reports in this series may be produced in a limited quantity and they are only available as long as the 

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

nature.nps.gov/publications/NRPM) or from http://www2.nature.nps.gov/air/monitoring/ads/ADSReport.cfm on the 

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

Please cite this publication as:

Ray, J.D. 2007. Annual Data Summary 2006: Gaseous Pollutant Monitoring Program, National Park Service Air 

Resources Division. Natural Resource Technical Report NPS ARD/NRPC/NRTR-2007/058. National Park Service, 

Denver, Colorado.

NPS D-1883, October 2007

Printed on recycled paper
 iii 

List of Figures ...............................................v

List of Tables .............................................. vii

Foreword .............................. ix

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

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

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

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

 

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

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

 Ozone Trends ....................................22

 Resource Injury Indices .......................34

Rocky Mountain National Park, 

Colorado

Horseshoe Park

Photo by Jessica Ward/

Air Resource Specialists, Inc.

Contents

 Recent Publications ............................33

 Sulfur Dioxide Data Summaries ..........38

 Particulate Matter Data Summaries ....40

 Meteorological Data Summaries ........44

Photographs

Rocky Mountain NP .................................... iii

Badlands NP .................................................v

Zion NP .................................................... vii

Lake Mead NRA .......................................... ix

Canyonlands NP ...........................................x

Acadia NP ....................................................2

Abraham Lincoln Birthplace NHS ..................3

Chiricahua NP ..............................................4

Theodore Roosevelt NP ..............................12

Grand Canyon NP ......................................18

Everglades NP ............................................31

Natchez Trace Parkway ..............................33

Hawaii Volcanoes NP ..................................38

North Cascades NP ....................................40

Glacier NP ..................................................42

Colorado NM .............................................44
 v 

Figure 1. Air quality monitoring 

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

Figure 2. Annual fourth highest 

daily maximum 8-hour average 

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

Figure 3. Annual number of days 

with daily maximum 8-hour 

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

Figure 4. Annual second highest

1-hour average ozone 

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

Figure 5. Three-year running

average ozone violation summary 

ranking (sites ≥ 80 ppb), 2004-2006 ........21

Figure 6. Map showing a simplifi ed 

version of ozone trends based on

on three categories. Trends analysis 

based on the Theil method as used

for the GPRA report .................................22

Figure 7. Map of ozone non-attainment 

areas with park units within the areas 

marked by red and blue dots. Based on

information from http://www.epa.gov/

air/data/nonat.html?us~USA~United%

20States ..................................................23

Figure 8. Time series plots for Great

Smoky Mountains NP and some 

non-urban monitors in the region ............28

Figure 9. Climatic trend plots for mean 

hourly ozone over the summer seasons 

at the Great Smoky Mountains -

Look Rock site, TN ...................................29

Figure 10. Climatic trend plots for mean 

hourly ozone over the summer seasons 

at the Great Smoky Mountains - 

Clingmans Dome site, TN .........................30

Figure 11. Statistical metrics available

for ozone trend plots .............................. 32

Figure 12. Annual 3-month maximum 

SUM06 exposure index ........................... 37

Figures

Badlands National Park, 

South Dakota

Photo by Dave Beichley/

Air Resource Specialists, Inc.
 vii 

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

Table 2. Summary of 8-hour average 

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

Table 3. Ozone violation summary - 

primary standard ..................................... 19

Table 4. Ozone trends based on the 

1997-2006 10-year period using Theil 

analysis ................................................... 24

Table 5. Station moves that may 

have affected ozone data collection. 

Combine data for trends with caution ..... 25

Table 6. Comparison of trend statistics 

for Great Smoky Mountains ozone 

monitoring stations ................................. 25

Table 7. Trends based on the 1990

reference period compared to the 

latest 3-year average for the NAAQS 

ozone metric ........................................... 26

Table 8. Status of Clean Air Act Class I

parks and their ozone trends ................... 27

Zion National Park, Utah

Photo by Joe Adlhoch/

Air Resource Specialists, Inc.

Tables

Table 9. Trend analysis using linear 

regression and Theil’s method on

de-seasonalized monthly mean O3

concentrations, daytime data

(1000-1800 LST). R2 and p-value

refer to regression trend. Values in 

bold are signifi cant with a p-value ≤.01 ...... 31

Table 10. Summary of indices for resource

injury (SUM06, W126, and N100) .............. 35

Table 11. Summary of sulfur dioxide data ... 39

Table 12. Summary of PM2.5 data from 

reference and equivalency methods ........... 41

Table 13. Summary of PM10 data from 

reference and equivalency methods ........... 43

Table 14. Summary of PM10 data from 

non-equivalency methods .......................... 43

Table 15. PM10 summary - 

daily standard ............................................ 43

Table 16. Summary of selected 

meteorological data ................................... 45
 ix 

Air quality and meteorological data 

from the National Park Service (NPS) 

monitoring sites for 2006 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 National Park Service 

Air Resources Division (ARD) Web site 

(http://www2.nature.nps.gov/air/data/

current/index.cfm).

Changes in 2006

Several report changes have been made 

this year to emphasize results from the 

monitoring and to include more analysis. 

Two signifi cant sections have been moved 

to the Web: the ozone trends plots for 

individual parks and the quality assurance 

tables showing data capture rates and results 

of precision and accuracy checks. In the 

fi rst case, this change allows for more trend 

plots to be made available and in the second, 

to reduce the number of pages devoted to 

bookkeeping tables.

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. Look for the draft monitoring strategy 

on the ARD Web site to see what is being 

proposed. 

Portable Ozone Monitoring Systems

The portable ozone monitoring systems 

(POMS) are continuing 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. Extensive testing of 

these systems has yielded equivalent results 

for summertime ozone measurements 

when compared to the full EPA-certifi ed 

instruments at fi xed-location stations. The 

NPS Inventory and Monitoring program 

is beginning to use more POMS to fi ll in 

baseline data at park locations that have 

never had air quality monitoring.

Lake Mead National Recreation 

Area, Arizona

Portable Ozone Monitoring System

Photo by Mike Slate/

Air Resource Specialists, Inc.

Foreword
 x 

In 2006, Joshua Tree National Park used 

POMS stations to get a West-East transect 

with six ozone monitoring sites. Summary 

data appear in this report’s tables, a more 

thorough publication will have fi nal 

results later. Use of these systems helped 

update and expand on monitoring done 

with passive ozone monitors in the past. 

If your park has an interest in deploying a 

POMS, please contact John Ray. For more 

information on the POMS, visit: http://

www2.nature.nps.gov/air/studies/portO3.

cfm.

Highlights in 2006

During 2006, only six sites, in four parks 

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. Four parks were in violation of 

the ozone standard based on the 3-year 

averages. Twelve monitors experienced 

one or more exceedances of the ozone 

Park/Site

4th Highest Daily Maximum

8-Hour Avg. O3

Concentration (ppb)

Number of 

Exceedances

Great Smoky Mountains:

 Clingmans Dome

 Look Rock

Joshua Tree - Black Rock

Sequoia and Kings Canyon:

 Ash Mountain

 Lower Kaweah

Yosemite - Turtleback Dome

 

86

85

103

104

97

85

4

6

36

49

17

4

standard during the year. Sequoia-Kings 

Canyon and Joshua Tree continue to 

experience 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 the volcano rather than from 

anthropogenic sources.

Network Quality Assurance

Overall data capture for NPS ozone 

monitoring continues to be high (97%) 

and exceeds NPS objectives and EPA 

requirements. The EPA accepts data from 

the NPS ARD as high quality and uses it 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).

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

Canyonlands National Park, Utah

NPS stock photo
1

The Air Resources Division (ARD) is 

responsible for providing policy and 

technical support to national parks on 

air quality issues. ARD has established 

monitoring networks for gaseous 

pollutants, wet and dry deposition, and 

visibility. This 2006 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. 

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 Air 

Resources Division (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, 

the ARD cooperates with other national 

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 at non-urban parks

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 (NPS) 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 

1963 (including the 1970, 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.

The NPS monitoring objectives call for the 

collection of data to support the National 

Park Service’s required involvement in 
 2

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://

www2.nature.nps.gov/air/Monitoring/

network.cfm#data.

Acadia National Park, Maine

NPS stock photo
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 2006, eighty-three (83) monitoring 

sites in fi fty-nine (59) units of the National 

Park System conducted some combination 

of ozone, sulfur dioxide, particulate matter, 

and meteorological monitoring. Of these, 

the NPS ARD supported forty-seven (47) 

monitoring sites in thirty-eight (38) 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. 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.

Abraham Lincoln Birthplace National 

Historic Site, Kentucky

Portable Ozone Monitoring System

Photo by Mike Slate/

Air Resource Specialists, Inc.

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

 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.

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: 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-hr 

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.

Cameras, which document the 

appearance of a scene as viewed through 

the atmosphere. 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 20 

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 80 

sites nationwide. More information about 

both of these programs is available at the 

NADP Web site: http://nadp.sws.uiuc.edu/.

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Chiricahua National Park, Arizona

Air Quality Monitoring Station

Photo by Martin Valvur/

Air Resource Specialists, Inc.
5

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

* Park units with more than one site are indicatedwith (x) following the park unit name, where xrepresents the number of sites within the unit.

Abraham Lincoln Birthplace

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado NM

Congare

Cowpens

Craters of the Moon

Cumberland Gap

Denali

Death Valley

Dinosaur

Glacier

Great Basin

Grand Canyon

Great Smoky Mountains (5)

Hawaii Volcanoes (2)

Joshua Tree (3)

Lake Mead

Lassen Volcanic

Mesa Verde

Mount Rainier (2)

Natchez Trace

Olympic North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (2)

Sh

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone (2)

Yosemite (2)

Zion

Appalach

Blue 

Blue Ridge Pa

Cuyahoga Valley

Gu

Indiana Dunes (3)

Mississippi (3)

Petroglyph

S

Alabama-Coushatta

Mammoth Cave

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)

Parameters

OzoneMeteorology

CASTNet FiSulfur Dioxi

Enhanced Ga
 6

Table 1. Site specifi cations.National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number Latitude Longitude

Elev.

(m)

O3

Yearsa SO2 VWDb SWSc TMP R

Sites operated by the National Park ServiceAbraham Lincoln Birthplace Visitor Center KY ABLI-KC --- --- 37.5314 85.7347 240 2 --- X X X Assateague Island Maintenance Area MD ASIS-MA --- --- 38.2511 75.1594 3 2 --- X X X Badlands Visitor Center SD BADL-VC --- 46-071-1001 43.7436 101.9414 739 10 X X X X Big Bend K-Bar Ranch Road TX BIBE-KB BBE401 48-043-0101 29.3022 103.1772 1052 17 --- X X X Canyonlands Island in the Sky UT CANY-IS CAN407 49-037-0101 38.455 109.8217 1813 15 --- X X X Carlsbad Caverns Maintenance Area NM CAVE-MA --- --- 32.1783 104.4406 1349 1 --- X X X Chiricahua Entrance Station AZ CHIR-ES CHA467 04-003-8001 32.0092 109.3892 1570 16 --- X X X Colorado Maintenance Yard CO COLM-MY --- --- 39.1067 108.7411 1740 1 --- X X X Craters of the Moon Visitor Center ID CRMO-VC --- 16-023-0101 43.4606 113.5622 1815 15 --- X X X Cumberland Gap Hensley Settlement KY CUHA-HS --- --- 36.6719 83.5264 1013 1 --- X X X Death Valley Park Village CA DEVA-PV DEV412 06-027-0101 36.5092 116.8481 125 14 --- X X X Denali Headquarters AK DENA-HQ DEN417 02-290-0003 63.0539 150.8547 661 20 --- X X X Dinosaur West Entrance Housing UT DINO-WE --- --- 40.4372 109.3047 1463 2 --- 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 15 --- X X X Grand Canyon The Abyss AZ GRCA-AS GRC474 04-005-8001 36.2828 113.0958 1433 14 --- X X X Great Basin Maintenance Yard NV GRBA-MY GRB411 32-033-0101 39.005 114.2158 2067 14 --- X X X Great Smoky Mountains Clingmans Dome TN GRSM-CD --- 47-155-0102 35.6967 83.6097 1265 14 --- X X X Great Smoky Mountains Cove Mountain TN GRSM-CM --- 47-155-0101 35.6967 83.6086 1243 19 X X X X Great Smoky Mountains Look Rock TN GRSM-LR GRS420 47-009-0101 35.59 83.0775 1500 19 --- 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 14 --- X X X Joshua Tree Cottonwood Canyon CA JOTR-CC --- 06-065-0008 33.7411 115.8206 984 2 --- X X X Joshua Tree Pinto Wells CA JOTR-PW --- --- 33.9397 115.4108 326 1 --- X X X Lake Mead Meadview AZ LAME-ME --- --- 36.0194 114.0686 881 6 --- X X X Lassen Volcanic Manzanita Lake Fire Station CA LAVO-ML LAV410 06-089-3003 40.5403 121.5764 1756 20 --- X X X Mammoth Cave Houchin Meadow KY MACA-HM MAC426 21-061-0501 37.1319 86.1478 243 12 X X X X Mesa Verde Resource Management Area CO MEVE-RM MEV405 08-083-0101 37.1983 108.4903 2177 14 --- X X X Mount Rainier Tahoma Woods WA MORA-TW MOR409 53-053-1010 46.7581 122.1225 423 16 --- X X X Mount Rainier White River WA MORA-WR --- --- 46.8919 121.5972 1193 1 --- X X X 
7

Table 1. Site specifi cations (continued).National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number Latitude Longitude

Elev.

(m)

O3

Yearsa SO2 VWDb SWSc TMP 

Sites operated by the National Park ServiceNatchez Trace Parkway Dancy Ranger Station MS NATR-DR --- --- 33.6636 89.0622 94 1 --- X X X North Cascades Marblemount Ranger Stn WA NOCA-MM NCS415 53-057-0013 48.5397 121.4472 109 11 --- X X X Olympic Hurricane Ridge Portable WA OLYM-HP --- --- 47.995 123.3847 939 3 --- X X X Padre Island Malaquite Visitor Center TX PAIS-MV --- --- 27.4267 97.2983 6 2 --- X X X Petrifi ed Forest South Entrance AZ PEFO-SE PET427 04-017-0119 34.8225 109.8919 1723 5 --- X X X Pinnacles SW of East Entrance Station CA PINN-ES PIN414 06-069-0003 36.485 121.1556 317 20 --- X X X 

Rocky Mountain Long’s Peak CO ROMO-LP ROM406 08-069-0007 46.4411 105.7539 3597 22 --- X X X Sequoia and Kings Canyon Ash Mountain CA SEKI-AS SEK430 06-107-0009 36.4894 118.8269 457 8 --- X X X Sequoia and Kings Canyon Lower Kaweah CA SEKI-LK --- 06-107-0006 36.5658 118.7772 1890 23 --- X X X Shenandoah Big Meadows VA SHEN-BM SHN418 51-113-0003 38.5231 78.4347 1073 24 X X X X Voyageurs Sullivan Bay MN VOYA-SB VOY413 27-137-0034 48.4128 92.8292 429 11 --- 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 11 --- X X X Yosemite School Yard CA YOSE-SY --- --- 37.7478 119.5917 1234 1 --- X X X Yosemite Turtleback Dome CA YOSE-TD YOS404 06-043-0003 37.7133 119.7061 1605 14 --- X X X Zion Dalton’s Wash UT ZION-DW --- 49-053-0130 37.1983 113.1506 1213 3 --- X X X  # active park units: 38 # active park sites: 47Sites operated by cooperating state agenciesAcadia Cadillac Mountain ME ACAD-CM --- 23-009-0102 44.3472 68.2278 466 12 --- X X X Acadia McFarland Hill ME ACAD-MH ACA416 23-009-0103 44.3739 68.2606 129 9 --- X X X Cape Cod Cape Cod MA CACO-XX --- 25-001-0002 41.9758 70.0247 41 20 --- X X X Chamizal Chamizal TX CHAM-XX --- 48-141-0044 31.7656 106.455 1128 15 --- X X X Congaree Congaree Bluff SC COSW-BL --- 45-079-0021 33.8147 80.7811 34 7 X --- --- --- Cowpens State Monitor SC COWP-SM --- 45-021-0002 35.1303 87.8164 297 19 --- --- --- --- Great Smoky Mountains Cades Cove TN GRSM-CC --- 47-009-0102 35.5619 83.4981 2021 14 --- X X X Great Smoky Mountains Purchase Knob NC GRSM-PK --- 37-087-0036 35.59 83.0775 1500 12 --- --- --- --- Saguaro Pima County AZ SAGU-PC --- 04-019-0021 32.1744 110.7364 938 15 --- --- --- --- Theodore Roosevelt Painted Canyon Visitor Cntr ND THRO-VC THR422 38-007-0002 46.8947 103.3778 850 9 X X X X Wind Cave Visitor Center SD WICA-VC WNC429 46-033-0132 43.5578 103.4839 1292 3 X X X X Yosemite Village CA YOSE-VI --- 06-043-1001 37.7458 119.6028 1216 --- --- --- --- ---  # active park units: 10 # active park sites: 12
 8

Table 1. Site specifi cations (continued).National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number Latitude Longitude

Elev.

(m)

O3 

Yearsa SO2 VWDb SWSc TMP R

Nearby sites operated by other agenciesAlabama-Coushatta CASTNet Site TX ALCO-CA ALC188 --- 38.8689 89.6228 164 19 --- X X X Appalachian Trail Mount Greylock Summit MA APTR-MG --- 25-003-4002 42.6367 73.1686 1140 18 --- --- --- --- -

Blue Ridge Parkway 7510 Blue Ridge Parkway NC BLRI-75 --- 37-011-0002 35.9717 81.9342 987 8 --- --- --- X Blue Ridge Parkway Barnet Knob Firetower Road NC BLRI-BK --- 37-099-0005 35.5244 83.2361 1433 8 --- --- --- --- -

Blue Ridge Parkway Blue Ridge Parkway NC BLRI-BR --- 37-199-0003 35.7378 82.2853 1982 15 --- --- --- --- -Blue Ridge Parkway Frying Pan Mountain NC BLRI-FP --- 37-087-0035 35.3792 82.7925 1585 13 --- --- --- --- -Blue Ridge Parkway Route 191 NC BLRI-RO --- 37-021-0030 35.5 82.6 675 18 --- --- --- --- -Blue Ridge Parkway Ranger Station VA BLRI-RS --- 51-163-0003 37.6261 79.5131 280 8 --- --- --- --- -Blue Ridge Parkway Vinton Elementary VA BLRI-VE --- 51-161-1004 37.2856 79.8842 346 26 X --- --- --- -Boston Harbor Islands Former Nike Missile Site MA BOHA-NM --- 25-025-0041 42.3175 70.9689 10 9 --- X X X Cuyahoga Valley 800 Patterson OH CUVA-PA --- 39-153-0020 41.1061 81.5039 305 27 --- --- --- --- -Everglades Cutler Road FL EVER-CR --- 12-086-0029 25.5861 80.3269 4 22 --- --- --- --- -George Washington Pkwy Alexandria Health VA GEWA-AH --- 51-510-0009 38.8108 77.0447 23 38 X --- --- --- -Guilford Courthouse Mendenhall Middle School NC GUCO-NM --- 37-081-0013 36.1092 79.8011 247 6 --- --- X X Indiana Dunes Ammunition Bunker IN INDU-AB --- 18-089-0022 41.5733 87.3047 183 14 --- X X X Indiana Dunes Gas Station IN INDU-GS --- 18-091-0005 41.7169 86.9075 187 31 X X X X -Indiana Dunes Water Treatment Plant IN INDU-WT --- 18-127-0024 41.6175 87.1992 183 24 --- --- --- --- -Mississippi Anoka County Airport MN MISS-AC --- 27-003-1002 41.1397 93.2075 281 28 X --- --- --- -Mississippi Somerset Town Hall WI MISS-ST --- 55-109-1002 45.1244 92.6625 278 40 --- X X --- -Mississippi Washington County MN MISS-WC --- 27-163-6015 45.1189 92.855 0 10 --- --- --- --- -Petroglyph Westside Taylor Ranch NM PETR-WT --- 35-001-0027 35.1519 106.6836 5111 8 --- --- --- X -Rock Creek Achbold Parkway DC ROCR-AP --- 11-001-0025 38.9753 77.0228 91 27 --- --- --- --- -
9

Table 1. Site specifi cations (continued).National Park Unit Site Name State

NPS

Abbr. 

CASTNet 

Abbr.

AQS

ID Number Latitude Longitude

Elev.

(m)

O3 

Yearsa SO2 VWDb SWSc TMP R

Nearby sites operated by other agenciesSaratoga Stillwater NY SARA-ST --- 36-091-0004 43.0122 73.6489 120 19 --- --- --- --- -Saugus Iron Works Lynn Water Treatment MA SAIR-LW --- 25-009-2006 42.4744 70.9725 52 15 --- X X X  # active park units: 15 # active park sites: 24a The values in this column represent the number of years an ozone analyzer has been operational at the site.b Cape Cod reports wind direction as scalar wind direction rather than vector wind direction.c Saguaro reports wind speed as vector wind speed rather than scalar wind speed.d 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 instrumentationParameter key: O3 = ozone analyzer VWD = vector wind direction TMP = ambient temperature RNF = precipitation DTP = delta tempera

 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

Ground-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. 

The primary NAAQS 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. 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 is the same as the primary 

standard.

This section presents 2006 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

 0.08 ppm 

0.03 ppm (primary)

0.14 ppm (primary)

0.5 ppm (secondary)

15.0 μg/m3

65 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

daily arithmetic mean

daily arithmetic mean
 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 

adults, 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 34, 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 EPA-certifi ed monitoring site, 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 2006. Note that other 

sites may have experienced fewer than four 

exceedances of the 8-hour standard, but are 

not color coded. Ozone summary statistics 

from POMS are not color coded and should 

be compared to EPA standards for reference 

purposes only.

In 2006, six of the NPS and cooperating state 

operated sites exceeded the 8-hour standard, 

as compared to eight sites in 2005. From 

2005 to 2006, six sites had an increase in the 

number of days with an exceedance of the 

8-hour standard and 10 sites 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. Data from portable sites 

(no color) 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 only.

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.

In 2006 there were fi res near the stations at 

Zion National Park that contributed to some 

very high hourly ozone values (Figure 4). 

Under EPA rules these values could probably 

meet the “exceptional event” criteria.

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).

Theodore Roosevelt National Park, 

North Dakota

Webcamera view
13

Table 2. 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 358 74 73 71 71 69 0

Big Bend K-Bar Ranch Road 355 67 66 66 65 65 0

Canyonlands Island in the Sky 361 73 71 70 70 70 0

Chiricahua Entrance Station 351 76 75 75 74 72 0

Craters of the Moonb Visitor Center 0 -- -- -- -- -- --

Death Valley Park Village 347 88 85 84 82 80 2

Denali Headquarters 355 60 57 54 53 53 0

Glacier West Glacier Horse Stables 346 67 63 61 59 58 0

Grand Canyon The Abyss 360 77 74 71 70 70 0

Great Basin Maintenance Yard 349 77 73 72 72 71 0

Great Smoky Mountains Clingmans Dome 185 89 88 88 86 84 4

Great Smoky Mountains Cove Mountain 359 86 85 81 80 80 2

Great Smoky Mountains Look Rock 356 89 87 86 85 85 6

Joshua Tree Black Rock 348 105 105 104 103 103 36

Joshua Tree Cottonwood Canyon 270 87 81 80 79 78 1

Lassen Volcanic Manzanita Lake Fire Station 353 77 75 75 74 74 0

Mammoth Cave Houchin Meadow 364 74 74 72 71 71 0

Mesa Verde Resource Management Area 360 84 79 74 74 72 0

Mount Rainier Tahoma Woods 351 75 72 64 64 62 0

North Cascades Marblemount Ranger Stn 348 60 60 56 53 51 0

Petrifi ed Forest South Entrance 307 85 73 71 71 71 1

Pinnacles SW of East Entrance Station 355 88 82 81 78 76 1

Rocky Mountain Long’s Peak 337 91 76 76 76 74 1

Sequoia and Kings Canyon Ash Mountain 299 109 107 104 104 103 49

Sequoia and Kings Canyon Lower Kaweah 348 101 99 98 97 95 17

Shenandoah Big Meadows 318 81 81 79 77 77 0

Voyageurs Sullivan Bay 318 68 68 64 63 63 0

Yellowstone Water Tank 338 82 70 70 69 69 0

Yosemite Turtleback Dome 289 94 88 87 85 84 4

Zion Dalton’s Wash 354 138 137 76 75 74 2

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 178 92 85 82 80 77 2

Acadia McFarland Hill 359 74 72 72 70 69 0

Cape Cod Cape Cod 178 106 104 98 82 81 3

Chamizal Chamizal 351 89 88 79 78 77 2

Congaree Congaree Bluff 350 81 79 74 72 71 0

Cowpens State Monitor 355 90 81 79 76 76 1

Great Smoky Mountains Cades Cove 241 74 73 72 71 71 0

Great Smoky Mountains Purchase Knob 203 78 77 74 73 73 0

Saguaro Pima County 362 80 76 76 76 76 0

Theodore Roosevelt Painted Canyon Visitor Cntr 359 70 67 67 66 66 0

Wind Cave Visitor Center 364 78 76 73 73 71 0

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet site 331 83 73 72 70 69 0

36

49

17

86 4

85 6

103

104

97

85 4
 14

Table 2. 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

Appalachian Trail Mount Greylock Summit 170 82 79 77 76 74 0

Blue Ridge Parkway 7510 Blue Ridge Parkway 199 72 70 68 67 67 0

Blue Ridge Parkway Barnet Knob Firetower Road 199 85 84 83 81 80 1

Blue Ridge Parkway Blue Ridge Parkway 49 79 69 67 61 61 0

Blue Ridge Parkway Frying Pan Mountain 199 87 81 80 79 75 1

Blue Ridge Parkway Route 191 213 83 78 71 71 67 0

Blue Ridge Parkway Ranger Station 151 73 72 69 68 68 0

Blue Ridge Parkway Vinton Elementary 212 83 82 78 76 76 0

Boston Harbor Islands Former Nike Missile Site 174 83 83 83 79 77 0

Cuyahoga Valley 800 Patterson 213 82 80 77 77 77 0

Everglades Cutler Road 359 95 80 78 71 69 1

George Washington Pkwy Alexandria Health 204 118 98 94 84 83 3

Guilford Courthouse Mendenhall Middle School 164 88 86 80 80 80 2

Indiana Dunes Ammunition Bunker 179 78 74 73 73 68 0

Indiana Dunes Gas Station 179 80 77 76 75 75 0

Indiana Dunes Water Treatment Plant 182 76 75 74 70 69 0

Mississippi Anoka County Airport 330 75 71 65 65 63 0

Mississippi Somerset Town Hall 358 76 74 70 68 67 0

Mississippi Washington County 180 80 72 69 68 68 0

Petroglyph Westside Taylor Ranch 357 79 74 73 72 72 0

Rock Creek Achbold Parkway 364 86 85 85 83 81 3

Saratoga Stillwater 273 90 80 75 73 71 1

Saugus Iron Works Lynn Water Treatment 346 86 84 79 78 77 1

Portable ozone monitoring systems

Abraham Lincoln Birthplace Visitor Center 109 79 78 78 77 75 0

Assateague Island Maintenance Area 152 88 86 84 84 83 2

Carlsbad Caverns Maintenance Area 107 78 77 75 74 73 0

Colorado Maintenance Yard 150 78 76 74 73 72 0

Cumberland Gap Hensley Settlement 154 80 79 74 71 70 0

Dinosaur West Entrance Housing 196 69 69 68 68 67 0

Joshua Tree Pinto Wells 120 89 85 83 83 82 2

Lake Mead Meadview 132 87 82 82 81 79 1

Mount Rainier White River 0 --- --- --- --- --- ---

Natchez Trace Parkway Dancy Ranger Station 170 72 70 68 67 66 0

Olympic Hurricane Ridge Portable 82 63 63 59 59 57 0

Padre Island Malaquite Visitor Center 150 89 83 82 80 77 1

Yosemite School Yard 115 76 72 71 71 70 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.

b Ozone data at Craters of the Moon were invalid in 2006 due to a leak that was found in the inlet tubing in Spring 2007. The leak was caused during roof replacement at the 

visitor center in Winter 2004.

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
15

Figure 2. 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

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado NM

Conga

Cowpens

Craters of the Moon

Cumberland

Gap

Denali

Death Valley

Dinosaur

Glacier

Great Basin

Grand Canyon

Joshua Tree

Lake Mead

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Rainier

Natchez Trace

North Cascades

Olympic

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (2) Shenandoah

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite

Zion

Appalach

Blu

Blue Ridge Parkway (south unit) (5)

Cuyahoga Va

Gu

Indiana Dunes (3)

Mississippi (3)

Petroglyph

Sa

Alabama-Coushatta

77

71

65

70

74 78 74

73

72

76

71

53

82

68

59

72

70

86 103

81

74

71

74

64

67

59 53

80

71

78

76

76

104

77

66

63

73

69

85

75

76

81

77

80

75

68

72

71

70

N/A
 16

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

Abraham Lincoln Birthplace

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado NM

C

Cowpen

Craters of the Moon

Cumberland Gap

Denali

Death Valley

Dinosaur

Glacier

Great Basin

Grand Canyon

Great Smoky Mountains (5) Joshua Tree

Lake Mead

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Rainier

Natchez Trace

Olympic North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (2) 

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite (2)

Zion

App

B

Blue Ridge 

Cuyahoga 

Indiana Dunes (3)

Mississippi (3)

Petroglyph

Alabama-Coushatta

655

N/A

0

0

0

0

0 2 0

0

0

1

0

0

2

0

0

0

0

6 36

1

0

0 0

0

0

0 0

1

1

1

1

0

49

0

0

0

0

4

2

0

1

0

2

0

0

0

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. 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)

Abraham Lincoln Birthplace

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal

Chiricahua

Colorado NM

Con

Cowpe

Craters of the Moon

Cumberland Gap

Denali

Death Valley

Dinosaur

Glacier

Great Basin

Grand Canyon

Joshua Tree

Lake Mead

Lassen Volcanic

Mammoth Cave

Mesa Verde

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

Zion

Appalac

B

Blue Ridge Parkway (south unit) (5)

Cuyahoga V

Indiana Dunes (3)

Mississippi (3)

Petroglyph

Sa

Alabama-Coushatta

95

77

70

75

84 108 79

82

85

102

86

62

91

79

69

84

78

96 124

90

86

83

89

86

79

69 74

96

90

104

106

86

117

92

73

71

84

88

99

184

91

98

90

111

91

86

83

11

90

N/A
 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 and 2004-2006 violation 

summaries are presented. 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 2006, four of the NPS and cooperating 

state-operated sites within three national 

park units were in violation of the NAAQS 

8-hour standard, down from six sites within 

fi ve units in 2005. No sites that operated 

independently of the NPS recorded a 

violation in 2006.

Figure 5 presents a ranked list of sites based 

on the 2004-2006 ozone violation summary 

data presented in the fi rst column of Table 3.

Only sites with a 3-year average fourth 

highest daily maximum 8-hour average of 80 

ppb or greater are presented in this fi gure.

Grand Canyon National Park, 

Arizona

Photo by Joe Adlhoch/

Air Resource Specialists, Inc.
19

Table 3. Ozone violation summary - primary standarda.

National Park Unit Site Name 2004 - 2006 2003 - 2005 2002 - 2004 2001 - 2003 2000 - 2002 1999 - 2001 1998 - 2000 1997 - 1999

Sites operated by the National Park Service

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

Big Bend K-Bar Ranch Road 63 63 62 62 (62) (63) 66 65

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

Chiricahua Entrance Station 72 71 70 69 69 70 70 68

Craters of the Moonb Visitor Center --- --- 67 (65) (63) (63) 66 (64)

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

Denali Headquarters 51 52 53 54 49 49 48 53

Glacier West Glacier Horse Stables 54 56 55 53 49 48 51 47

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

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

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

Great Smoky Mountains Cove Mountain 77 78 86 92 96 96 101 (100)

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

Joshua Tree Black Rock 103 105 106 99 94 92 102 109

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

Lassen Volcanic Manzanita Lake Fire Station 69 68 71 72 74 77 78 76

Mammoth Cave Houchin Meadow 72 73 77 80 84 88 94 (92)

Mesa Verde Resource Management Area 73 70 68 67 69 69 70 (66)

Mount Rainier Tahoma Woods (58) (61) 63 61 56 60 57 51

North Cascades Marblemount Ranger Stn (48) (51) 51 50 46 48 46 43

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

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

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

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

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

Shenandoah Big Meadows 77 (80) 82 87 85 87 93 96

Voyageurs Sullivan Bay 64 66 64 65 (64) 67 68 70

Yellowstone Water Tank 63 61 63 65 65 67 67 65

Yosemite Turtleback Dome 86 88 90 90 89 86 88 86

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

 # park units with violations:

 # sites with violations:

3

4

4

5

4

7

5

8

5

8

6

9

6

9

6

9

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 80 82 88 94 93 89 87 (89)

Acadia McFarland Hill 71 74 80 87 84 85 83 (90)

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

Chamizal Chamizal 73 72 78 79 81 75 (79) (76)

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

Cowpens State Monitor 74 75 80 84 87 87 92 93

Great Smoky Mountains Cades Cove 67 (67) 73 76 79 81 (85) (83)

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

Saguaro Pima County 76 (76) (75) (76) (54) (33) (33) (33)

Theodore Roosevelt Painted Canyon Visitor Cntr 60 59 60 61 59 58 (57) (56)

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

 # park units with violations:

 # sites with violations:

0

0

1

1

2

2

3

4

4

4

4

5

4

5

4

5

106

86

103 105

(87)

86

109

94

86

94

91

92

(92)

96

92

(98)

99

(98)

92

88

96

96 101

102

(102)

104

(92)

(100)

(98)

94

104

86 88 90 90 89 86 88

87 85 87 93 96

101 101 98 (94) (93) (96)

(103) (104)

96 97

(105) (105) (107) (105) (105) (105)

86

(90)

(95)

93

90 90

(85)

92

89

87

87

87

96

85

89

88

87

93

93

95

87

94

88

88 (89)

86
 20

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

National Park Unit Site Name 2004 - 2006 2003 - 2005 2002 - 2004 2001 - 2003 2000 - 2002 1999 - 2001 1998 - 2000 1997 - 1999

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet Site (71) (72)

Appalachian Trail Mount Greylock Summit (78) (80)

Blue Ridge Parkway 7510 Blue Ridge Parkway 69 71

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

Blue Ridge Parkway Blue Ridge Parkway (70) 76

Blue Ridge Parkway Frying Pan Mountain 78 78

Blue Ridge Parkway Route 191 74 74

Blue Ridge Parkway Ranger Station (69) 71

Blue Ridge Parkway Vinton Elementary 74 74

Boston Harbor Islands Former Nike Missile Site 81 81

Cuyahoga Valley 800 Patterson 81

Everglades Cutler Road 68 66

George Washington Pkwy Alexandria Health 81 81

Guilford Courthouse Mendenhall Middle School (81) (82)

Indiana Dunes Ammunition Bunker 75 76

Indiana Dunes Gas Station 76 78

Indiana Dunes Water Treatment Plant 76 78

Mississippi Anoka County Airport 66 68

Mississippi Somerset Town Hall 67 (69)

Mississippi Washington County (67) (68)

Petroglyph Westside Taylor Ranch 71 72

Rock Creek Achbold Parkway 80 78

Saratoga Stillwater 83 83

Saugus Iron Works Lynn Water Treatment 77 82

 # park units with violations:

 # sites with violations:

0

0

1

1

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.

b Ozone data at Craters of the Moon were invalid in 2006 due to a leak that was found in the inlet tubing in Spring 2007. The leak was caused during roof replacement at the 

visitor center in Winter 2004.

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. 

85
21

Figure 5. Three-year running average ozone violation summary ranking (sites ≥ 80 ppb), 2004-2006.

0 20 40 60 80 100 1

Joshua Tree - Black Rock

Sequoia and Kings Canyon -

Ash Mountain

Sequoia and Kings Canyon -

Lower Kaweah

Yosemite - Turtleback Dome

Cape Cod

Great Smoky Mountains -

Look Rock

Saratoga - Stillwater

Death Valley - Park Village

Boston Harbor Islands -

Former Nike Missile Site

Cuyahoga Valley - 800

Patterson

Gearge Washinton Pkwy -

Alexandria Health

Guilford Courthouse -

Mendenhall Middle School

Acadia - Cadillac Mountain

Great Smoky Mountains -

Clingmans Dome

Rock Creek - Achbold Parkway

Zion - Dalton's Wash

Ozone Concentration (ppb)

85 ppb or greater 

violates the 8-hr ozone 

National Ambient Air 

Quality Standard
 22

Ozone Trends 

An important objective of the GPMP 

network is determining ozone trends, 

usually calculated based on 1-hour 

average (old NAAQS metric) or 8-hour 

average (current NAAQS metric) ozone 

concentrations. Trend analysis can help 

scientists relate changes in ozone levels 

to factors that control its concentration, 

including precursor emissions, climate 

changes, changing transport patterns, 

global transport, and short-term 

events such as wildfi res. Some of the 

methods used for trend analysis and the 

usefulness of the resulting information 

were discussed in the 2005 Annual Data 

Summary Report1. This report presents 

some factors to consider in trends 

evaluations and includes details on trends 

from several specifi c parks and regions.

As part of the annual Government 

Performance and Results Act (GPRA) 

report, each year the NPS ARD estimates 

ozone trends from monitoring stations 

in or very near park units using the Theil 

method2. (For more detail on these trend 

results, consult the 2007 GPRA report.) 

As can be seen in Figure 6, most GPMP 

network sites show either an improvement 

in ozone concentrations or no change. 

This is especially true in the Eastern United 

States and in California, with a couple of 

exceptions. However, some mountainous 

regions in the West show degrading ozone 

concentrations. Figure 7 displays areas of 

the country that are currently classifi ed by 

the EPA as non-attainment areas based on 

the ozone standard. Reviewing ozone trends 

from parks in or near these areas reveals that 

most sites next to non-attainment areas show 

improving or stable ozone conditions. Rocky 

Mountain National Park is an exception to 

this since it exhibits an increasing trend in 

ozone concentrations. (Denver is listed as an 

Early Action Area, not technically a nonattainment area.)

Figure 6. Map showing a simplifi ed 

version of ozone trends based on 

three categories. Trends analysis 

based on the Theil method as used 

for the GPRA report. 
23

Acadia National Park in Maine and 

Shenandoah National Park in Virginia 

are examples of two Eastern park units 

that are close to violation of the standard, 

but due to recent decreases in ozone 

concentrations are currently in attainment. 

Two monitoring stations operate in 

Acadia National Park: McFarland Hill 

and Cadillac Mountain. The McFarland 

Hill station returned to compliance of 

the ozone standard in the mid-1990s 

and has remained just below the 8-hour 

average standard ever since. At the 

Cadillac Mountain site, which is at a higher 

elevation than McFarland Hill, the ozone 

concentrations are slightly higher and 

the station came into compliance only in 

the last couple of years. At ShenandoahBig Meadows, ozone increased during the 

1990s to above the 8-hour average standard, 

but since the peak in 1999, the ozone 

concentrations have decreased and the 

park is currently below and in attainment 

of the standard. Although these two parks 

are currently in attainment, since the start 

of monitoring at these two parks the net 

change in the highest ozone concentrations 

has shown no improvement at Cadillac 

Mountain and Big Meadows. At McFarland 

Hill in Acadia, there has been a decrease in 

ozone concentrations since the high in 1988, 

but there are large swings in annual highest 

concentrations. Ozone should be watched 

carefully at these two parks to see if the 

current improving trend persists.

Figure 7. Map of ozone nonattainment areas with park units 

within the areas marked by red and 

blue dots. Based on information 

from http://www.epa.gov/air/data/

nonat.html?us~USA~United%20States.
 24

Ozone trends based on changes in 

the 3-year average of the annual 

fourth highest daily maximum 8-hour 

concentration over a 10-year period 

using the Theil analysis technique have 

been widely reported and serve as the 

basis for the ARD GPRA report. This 

trend is expressed as a change in ozone 

concentrations (in ppb) per year where 

negative slopes correspond to improving 

ozone conditions. This approach does not 

consider if ozone concentrations are high 

or low at individual sites, but only if ozone 

concentrations are trending upward or 

downward. To identify potential trends 

early, a statistical signifi cance based on 

a more lenient p-value of 0.15 is used, 

rather than a stricter, more robust p-value 

of 0.05. The Theil trends, as presented in 

the GPRA report, are included in Table 4. 

Trends with p-values less than or equal 

to 0.15 are indicated in dark green. Three 

trend categories are provided in this 

table: a degrading trend (highlighted in 

blue), no change in trend (no highlight), 

and improving trend (highlighted in 

light green). There are more parks with 

improving (a decreasing trend) or no 

change than with degrading (an increasing 

trend) ozone air quality. Thirteen (13) 

parks show a strongly signifi cant trend 

based on a p-value of 0.05 or better. 

In any trend determination there is an 

uncertainty band in which Improving or 

Degrading air quality is indeterminate. 

Various factors contribute to this No 

Change band, including the following:

Lack of statistical signifi cance – Trends 

with a statistical signifi cance of p = 0.05 

or less can be considered acceptable. 

P-values in the range of 0.05 to 0.15 have 

greater uncertainty but are considered in 

the GPRA report as statistically signifi cant. 

P-values greater than 0.15 should be 

considered no trend.

Trend change is small – The slope of a 

trend is also important. Very small slopes 

are indistinguishable from a slope of 

zero. A slope of 0.10 ppb/yr, for example, 

represents a change of only 1 ppb over 

10 years. This is not an important change 

and because of instrument uncertainties, 

would be very hard to distinguish. As 

a practical matter, an overall change in 

ozone of 3-5 ppb over 10 years is needed. 

For this analysis, the range within which 

a trend is considered too small to be 

determined is -0.5 to 0.5 ppb per year.

Table 4. Ozone trends based on the 1997-2006 10-year 

perioda using Theil analysis.

Park

Theil Trenda

ppb/yr p-value

Mammoth Cave -3.67 0.00

Channel Islands -2.00 0.04

Big Thicket -1.83 0.00

Shenandoah -1.50 0.15

Cowpens -1.00 0.11

Joshua Tree -1.00 0.15

Cape Cod -1.00 0.02

Pinnacles -1.00 0.00

Big Bend -0.83 0.00

Voyageurs -0.58 0.09

Lassen Volcanic -0.57 0.15

Yellowstone -0.53 0.20

Saguaro -0.50 0.11

Great Smoky Mountains -0.14 0.43

Sequoia / Kings Canyon -0.14 0.36

Great Basin 0.00 0.24

Yosemite 0.13 0.36

Denali 0.14 0.30

Canyonlands 0.33 0.04

Grand Canyon 0.33 0.00

Craters of the Moon 0.40 0.15

Mesa Verde 0.43 0.02

Death Valley 0.50 0.00

Theodore Roosevelt 0.67 0.14

Acadia 0.83 0.18

Glacier 0.83 0.02

Mount Rainier 0.83 0.15

Rocky Mountain 1.00 0.01

North Cascades 1.29 0.00

a As reported in the GPRA report for 2007 (1997-2006).

italics = site operated by a state agency

Improving

Degrading

Statistically Signifi cant at <0.15
25

Method, site, and instrument uncertainties –

Errors in trend determination are 

introduced if other variability in data is 

not considered. Over the 20 or more years 

that air quality monitoring stations have 

been in the parks, changes in instruments, 

shelter types, inlet confi gurations, inlet 

heights, shelter locations, operators, 

calibration equipment, and standard 

operating procedures have all changed 

slightly. These factors aff ect the trend 

assessments and have not always been 

taken into account when reporting trends. 

Table 5 lists monitoring stations that have 

moved location in the past. Trend data 

from these sites should be treated carefully. 

Between 1995 and 1997, most monitoring 

stations had inlet confi guration changes 

and inlet height changes from 3.5 meters 

to 10 meters as part of standardization to 

CASTNet procedures. Although there is 

little indication that the inlet change made 

much diff erence in ozone concentrations, 

recent comparisons of ozone analyzers 

Table 5. Station moves that may have affected ozone data collection. Combine data for trends with caution.

Park Name Old Site ID Location 1 Dates Location 2 Dates New Site ID

Yellowstone YELL-LY Lake 1987-1996 Water Tank 1996-present YELL-WT

Mammoth Cave MACA-OC Onyx Cave 1984-1997 Houchin Meadow 1997-present MACA-HM

Joshua Tree JOTR-LH Lost Horse 1987-1993 Black Rock (Yucca Valley) 1993-present JOTR-BR

Voyageurs VOYA-BB Black Bay 1987-1996 Sullivan Bay 1996-present VOYA-SB

Acadia ACAD-HQ Headquarters 1982-1997 McFarland Hill 1998-present ACAD-MH

Table 6. Comparison of trend statistics for Great Smoky Mountains ozone monitoring stations.

Site

Years of 

data Elevation (m)

Regression Slope 

(to 2006) R2

Theil Slope

1996-2005

p-value

1996-2005

Cades Cove 13 564 -1.08 0.38 -1.00 0.15

Look Rock 22 793 0.27 0.07 -1.13 0.05

Cove Mountain 19 1243 0.11 0.01 -1.33 0.15

Purchase Knob 7 1500 -3.00 0.96 -1.00 0.13

Clingmans Domea 14 2021 -0.19 0.01 -0.14 0.43

a Operated during the summer season only.

at diff erent inlet heights have shown 

diff erences during daily periods when the 

atmospheric boundary layer is changing 

rapidly after sunrise and around sunset. 

Since these periods do not coincide with 

peak daily ozone, there is no eff ect on metrics 

such as the 4th highest daily maximum 8-hour 

ozone.

Data from multiple monitoring sites are 

available – Some park units have multiple 

monitoring sites that show slightly diff erent 

ozone concentrations and patterns. In the 

GPRA report, only the station with the 

largest trend is reported. As Table 6 shows 

for Great Smoky Mountains, the station 

and time period selected makes a diff erence 

in trend analysis. All of the Great Smoky 

Mountains ozone stations have reported an 

improvement in ozone concentrations since 

1999, yet the regression slopes reported in 

Table 6 have no consistent agreement. The 

Purchase Knob station record is too short 

for an accurate comparison to the other 

stations.
 26

A simple approach to trends was used 

in the 2005 Annual Data Summary 

Report that presented the diff erence 

between a base year and the present. 

There are a number of parks where 

direct ozone monitoring since 1990 has 

occurred and the change in the 8-hour 

ozone metric used for the NAAQS can 

be used for a trend. In contrast to the 

Theil analysis previously discussed, this 

analysis, presented in Table 7, allows for 

a comparison between current values 

and the standard. The number of parks 

violating the NAAQS and the number 

within 80% of the NAAQS have been 

decreasing (air quality improving). 

Thus, the number of parks in Table 7 

Table 7. Trends based on the 1990 reference period compared to the latest 3-year average for the NAAQS 

ozone metric.

EPA 

Region Park Name

1988-1990

4th Highest

Daily Maximum

8-Hour

2004-2006

4th Highest 

Daily Maximum 

8-Hour

1990-2006

% Change

1 Acadia National Park - Cadillac Mountain 93 80 -14

1 Cape Cod National Seashore 110 84 -24

4 Cowpens National Battlefi eld 75 74 -1

10 Denali National Park 49 51 4

9 Great Basin National Park 54 72 33

4 Great Smoky Mountains NP - Cove Mountain 84 77 -8

4 Great Smoky Mountains NP - Look Rock 84 84 0

9 Joshua Tree National Park - Black Rock 98 103 5

9 Lassen Volcanic National Park 73 69 -5

4 Mammoth Cave National Park 92 72 -22

9 Pinnacles National Monument 83 75 -10

8 Rocky Mountain National Park 67 74 10

9 Saguaro National Monument 74 76 3

9 Sequoia National Park - Lower Kaweah 95 96 1

3 Shenandoah National Park - Big Meadows 86 77 -10

8 Theodore Roosevelt National Park - South 64 60 -6

5 Voyageurs National Park 57 64 12

8 Yellowstone National Park 61 63 3

Codes:

Less than 80% of NAAQS

Greater than 80% of NAAQS

Violation of the NAAQS

Trend: Degrading ozone

Trend: Improving ozone

italics = site operated by a state agency

with ozone above the NAAQS dropped 

from seven to two between 1990 and 2006. 

Seven parks show a long-term degradation 

in air quality, while nine show a long-term 

improvement. Notable successes in ozone 

reduction at eastern parks have occurred at 

Great Smoky Mountains, Mammoth Cave, 

and Shenandoah, where ozone at these 

parks has dropped below the NAAQS. The 

parks showing increases in ozone levels 

include: Denali, Great Basin, Joshua Tree, 

Rocky Mountain, Saguaro, Voyageurs, and 

Yellowstone. Parks violating the standard in 

California have not improved and still have 

a signifi cant number of days when ozone 

concentrations exceed the standard.
27

Trends for Parks in Non-Attainment and 

Nearby Areas

Table 8 presents ozone trends for areas that 

are in non-attainment. In the last six years, 

ozone concentrations at Mammoth Cave, 

Great Smoky Mountains, Shenandoah, 

Cape Cod, and Cowpens have decreased 

so that none of these parks are currently 

in violation of the NAAQS. This decrease 

is important from a regulatory standpoint 

and indicates a decreased likelihood of 

resource injury. As shown in Figure 8, these 

sites had a large increase in ozone peaking 

around 1999, followed by a rapid decrease, 

a sequence that confounds the statistical 

trends and probably relates to ozone 

precursor emissions in the region. Trend 

plots for other rural monitors in the region 

around Great Smoky Mountains National 

Park are given for comparison. Peak ozone 

values occurred around 1999-2000 and 

have decreased since. If the entire periods 

of record are used, the statistical trend 

methods suggest no change or a slight 

decrease. In the next two years, the Theil 

method is likely to show a strong decrease 

in ozone as the 10-year period includes 

more points since 1999.

Another view of ozone at Great Smoky 

Mountains can be gained by taking a 

climatic approach. In Figures 9 and 10, the 

seasonal mean ozone concentrations are 

plotted by year and color-coded contours 

to help to illustrate the changes in ozone 

by time of day and year. This approach 

shows the lower elevation site at Look Rock 

follows a diurnal pattern with peak ozone 

concentrations in late afternoon. Ozone 

increases for the 5 pm hour until about 

1999 (the dashed hour-17 line on the Mean 

Ozone Climatic Pattern moves from green, 

through yellow and orange to red) then 

starts to decrease again. The 9 am hour and 

5 pm hour ozone values are plotted in the 

time series below to help present the trend.

The high elevation Clingmans Dome site 

has a diff erent diurnal pattern with peak 

ozone concentrations late at night and the 

lowest ozone values during mid-day. This 

site also has an ozone peak around 1999 

with decreasing values afterwards. The 

noon hour and midnight hour time series 

show this pattern. Clingmans Dome is 

cut off from the nighttime boundary layer, 

which is when it reports its highest ozone 

concentrations. In contrast, Look Rock 

reports its highest ozone concentrations 

during the daytime when the site is within 

the boundary layer. Clingmans Dome ozone 

data represents more of the regionally 

transported air pollution and Look Rock 

data more of the locally transported air 

pollution, yet both sites indicate decreasing 

ozone concentrations over the last 6 years. 

Both the highest ozone concentrations 

and the mean concentrations of ozone are 

decreasing at Great Smoky Mountains.

Table 8. Status of Clean Air Act Class I parks and their ozone trends.

Non-attainment Areas

Park Name

2004-2006

O3 3-year

Averagea Trendb

Slope

ppb/yr p-valuec

Yosemite - Turtleback Dome 86 +0.13 0.36

 Sequoia - Ash Mountain 103 -0.14 0.36

Joshua Tree - Black Rock 103 -1.00 0.15

Rocky Mountain 74 +1.00 0.01

Great Smoky Mountains - Look Rock 84 -0.14 0.43

Maintenance Areasd

Shenandoah 77 -1.50 0.15

Acadia - Cadillac Mountain 80 -1.00 0.05

a 4th highest annual daily maximum 8-hr average ozone, ppb. b Theil technique, 4th highest 8-hour O3, 10-year period, break points by p-value. c p-values greater than 0.15 indicate trends are not signifi cant. d Maintenance areas are designated when an area comes out of non-attainment, but is still near the standard.

italics = site operated by a state agency
 28

Figure 8. Time series plots for Great Smoky Mountains NP and some non-urban monitors in the region. 

3-yr avg of 4th hi daily 

Cowpens

405060708090

100110

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 

Y

Ozone (ppb)

3-yr avg of 4th hi daily max 8-h O3

Great Smoky Mountains - Look Rock

405060708090

100110

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Year

Ozone (ppb)

3-yr avg of 4th hi daily max 8-h O3

Great Smoky Mountains - Cove Mountain

y = 0.1078x - 126.12

R2 = 0.0056

405060708090

100110

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Year

Ozone (ppb)

3-yr avg of 4th hi daily max 8-h O3

Mammoth Cave

y = -0.5173x + 1116.2

R2 = 0.153 40

5060708090

100110

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Year

Ozone (ppb)

3-yr avg of 4th hi daily m

Shenandoah

y = 0.2236x - 362.29

R2 = 0.0736

405060708090

100110

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 199

Ye

Ozone (ppb)

Mammoth Cave

Great Smoky Mtns

Cowpens

Shenandoah

Lawrence County

SITE= 470990002 POC=1

Murray County

SITE= 132130003 POC=1
29

Figure 9. Climatic trend plots for mean hourly ozone over the summer seasons at the Great Smoky Mountains - Look Rock site, TN.

Figure

Great Smoky MouLook Rock site793 m elevation

0123456789

1011121314151617181920212223

hour

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

YEAR

seas

_

hr

_

mean

<= 30<= 35<= 40<= 45<= 50<= 55<= 60<= 65> 65

Legend

303540455055606570

seas_hr_mean

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

YEAR

9 am

303540455055606570

seas_hr_mean

1988 1990 1992 1994 1996 1998 

YEAR

5 pm

303540455055606570

Mean(seas_hr O3)

0 3 6 

Diurn

Mean Ozone Climatic Pattern

Great Smoky MouLook Rock site793 m elevation

0123456789

1011121314151617181920212223

hour

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

YEAR

seas

_

hr

_

mean

<= 30<= 35<= 40<= 45<= 50<= 55<= 60<= 65> 65

Legend

303540455055606570

seas_hr_mean

1988 1990 1992 1994 1996 1998 2000 2002 2004 2006

YEAR

9 am

303540455055606570

seas_hr_mean

1988 1990 1992 1994 1996 1998 

YEAR

5 pm

303540455055606570

seas_hr_mean

1988 1990 1992 1994 1996 1998 

YEAR

5 pm

303540455055606570

Mean(seas_hr O3)

0 3 6 

Diurn

Mean Ozone Climatic Pattern
 30

Figure 10. Climatic trend plots for mean hourly ozone over the summer seasons at the Great Smoky Mountains - Clingmans Dome site, TN.

303540455055606570

seas_hr_mean

1992 1994 1996 1998 2000 2002 2004 2006

YEAR

0123456789

1011121314151617181920212223

hour

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

YEAR

seas

_

hr

_

mean

<= 30<= 35<= 40<= 45<= 50<= 55<= 60<= 65> 65

Legend

12 noon

303540455055606570

seas_hr_mean

1992 1994 1996 1998 2000 

YEAR

midnight

Great Smoky MouClingmans Dome site2021 m elevation

303540455055606570

Mean(seas_hr O3)

0 3 6 

Diurn

Mean Ozone Climatic Pattern

303540455055606570

seas_hr_mean

1992 1994 1996 1998 2000 2002 2004 2006

YEAR

0123456789

1011121314151617181920212223

hour

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

YEAR

seas

_

hr

_

mean

<= 30<= 35<= 40<= 45<= 50<= 55<= 60<= 65> 65

Legend

12 noon

303540455055606570

seas_hr_mean

1992 1994 1996 1998 2000 

YEAR

midnight

303540455055606570

seas_hr_mean

1992 1994 1996 1998 2000 

YEAR

midnight

Great Smoky MouClingmans Dome site2021 m elevation

303540455055606570

Mean(seas_hr O3)

0 3 6 

Diurn

Mean Ozone Climatic Pattern
31

Everglades National Park, Florida

NPS stock photo

Western Parks De-Seasonalized Trends

A number of western NPS monitoring sites 

were selected for additional trends analysis 

that uses monthly statistical values rather 

than just a single ozone summary statistic 

for each year. Relatively remote sites were 

chosen that were mostly unaff ected by 

nearby pollution sources (Jaff e and Ray, 

20073) and had extended periods (15 years 

or more) of ozone data. Hourly averages 

were converted into daytime (10 am - 6 pm 

local time) monthly means. The seasonal 

component was removed from the monthly 

means using the seasonal decomposition 

procedure in SPSS (statistical analysis) 

software. The month-to-month seasonal 

variation was removed by subtracting from 

each monthly concentration the mean 

monthly values for the whole period being 

examined. Linear regression analysis was 

Table 9. Trend analysis using linear regression and Theil’s method on de-seasonalized monthly mean O3 concentrations, daytime data (1000-1800 LST). R2 and 

p-value refer to the regression trend. Values in bold are signifi cant with a p-value ≤ .01.

Site Mean

# days > 80 ppb

in data recorda Regression trend R2 p-value

Theil trend

(ppbv/year)

Rocky Mountain 47.2 19 0.51 0.22 <0.01 0.48

Yellowstone 43.6 0 0.50 0.32 <0.01 0.45

Lassen Volcanic 43.3 6 0.33 0.17 <0.01 0.32

Canyonlands 48.0 0 0.28 0.11 <0.01 0.26

Craters of the Moon 44.0 0 0.22 0.05 0.01 0.22

Denali 32.4 0 0.08 0.02 0.06 0.13

Glacier 32.8 0 0.00 0.00 0.45 -0.08

a This column gives the number of days in the data record with 8-hour daily maximum O3 concentrations greater than 0.08 ppm.

then conducted on the de-seasonalized 

values .This procedure gives a robust 

measure of the trend, so long as the trend is 

present and relatively uniform in all seasons.

The de-seasonalized monthly means 

trend results are presented in Table 9. 

Good agreement was obtained using the 

regression technique and the Theil method 

on the de-seasonalized monthly means. 

Rocky Mountain and Yellowstone show 

degrading ozone conditions of about 0.5 

ppb/year. Rocky Mountain National Park 

is closer to the national ozone standard 

than Yellowstone, therefore the eff ect that 

increasing ozone concentrations has on 

park resources and visitors may be evident 

there fi rst. Greater detail on the trend 

technique summarized here can be found in 

Jaff e and Ray, 20073.
 32

Web Resources to Plot Ozone Trends for 

Parks

Trends plots for GPMP ozone monitoring 

stations can be plotted interactively from 

the NPS Web site at: http://www2.nature.

nps.gov/air/monitoring/o3Plots/index.cfm. 

At this Web site several diff erent statistical 

metrics can be used (Figure 11).

Previously, selected trend plots were 

included in the Annual Data Summary 

Report. Now all of these plots for all sites 

are available from the Web site.

Reviewing trends plots based on these 

diff erent statistics allows for a more 

complete picture of ozone changes over 

time in park units. On the Web page, 

an example trend plot is shown for 

Rocky Mountain National Park, that has 

remained below the ozone standard based 

on the 3-year average used to determine 

violations. However, the trend in ozone 

has been upward and recent data approach 

the standard. When plotting the number 

of exceedances (refer to http://www.epa.

gov/airtrends/ozone.html) infrequent 

exceedances of 85 ppb based on daily 

maximum 8-hour ozone concentrations 

appear. In 2002 and 2003, six and seven 

exceedances occurred, respectively. These 

two high years correspond to hot, drought 

conditions in Colorado. Emissions 

from wildfi res in Colorado and other 

Western states likely contributed to ozone 

formation during these two years. The 

high variability from year to year and the 

infl uence of multiple factors, even when 

a strong trend appears to be present, is 

illustrated by this example.

Other ozone trends information for 

CASTNet and state operated monitoring 

locations is available on the Internet at: 

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

Figure 11. Statistical metrics 

available for ozone trend plots.

The EPA has two Web sites for ozone trends. 

Trends in the NAAQS metric (annual 4th

highest daily average 8-hour ozone) are 

available at: http://www.epa.gov/airtrends/

ozone.html. Use the map at the bottom of the 

Web page to select a state and then select a 

monitoring station.

Meteorologically adjusted ozone trends 

for selected sites are plotted at http://www.

epa.gov/airtrends/weather.html. The 

adjusted trends posted here remove weather 

variations due to temperature and humidity 

fl uctuations that occur between years so that 

a more accurate relationship between ozone 

and emissions can be assessed.

More information on the Web

Annual 4th highest 8-hr concentrations 

in parks http://www2.nature.nps.gov/air/

monitoring/docs/2006_O3ParkConc.pdf

Annual NAAQS exceedance counts in 

parks http://www2.nature.nps.gov/air/

monitoring/docs/2006_O3ParkExceedDays.

pdf

Performance measures (GPRA report on 

trends) http://www2.nature.nps.gov/air/

who/npsPerfMeasures.cfm

Ozone interpolation maps as 5-year 

averages (Air Atlas) http://www2.nature.

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

NPS GIS map products for ozone http://

www2.nature.nps.gov/air/maps/AirAtlas/

gisprojects.cfm

References

1 Annual Data Summary Report for 2005; 

NPS Gaseous Pollutant Monitoring Program, 

Air Resources Division, July 2006. http://

www2.nature.nps.gov/air/Monitoring/ads/

ADSReport.cfm

2 2007 GPRA report, http://www2.nature.

nps.gov/air/who/npsPerfMeasures.cfm

3 Dan Jaff e and John Ray, Increase in surface 

ozone at rural sites in the Western U.S, 

Atmospheric Environment, 41, 5452-5463 

(2007).

•

•

•

•

•
33

Natchez Trace Parkway, Mississippi

Portable Ozone Monitoring System

Photo by Mike Slate/

Air Resource Specialists, Inc.

Recent Published Articles that Use NPS Air 

Quality Data 

Art Chappelka, Howie Neufeld, Sandy 

McLaughlin, Susan Sachs, and Jim Renfro, 

Ozone Pollution Damage to Growth 

and Physiology of Native Trees and 

Wildfl owers in Great Smoky Mountains 

National Park, Final Report (June 2006). 

http://www2.nature.nps.gov/air/Pubs/pdf/

ChapelkaReport2005.pdf

Joel D. Burley and John D. Ray, Surface 

ozone in Yosemite National Park, 

Atmospheric Environment, 41, 6048-6062 

(2007).

Thomas J. Butler, Gene E. Likensa, 

Francoise M. Vermeylenc, Barbara J.B. 

Stunder, The impact of changing nitrogen 

oxide emissions on wet and dry nitrogen 

deposition in the northeastern USA, 

Atmospheric Environment, 39, 4851-4862 

(2005).

N. E. Grulke, H. S. Neufeld, A. W. Davison, 

M. Roberts and A. H. Chappelka, Stomatal

behavior of ozone-sensitive and 

–insensitive conefl owers (Rudbeckia 

laciniata var. digitata) in Great Smoky 

Mountains National Park, New Phytologist 

173: 100-09 (2007).

Dan Jaff e and John Ray, Increase in surface 

ozone at rural sites in the Western U.S,

Atmospheric Environment, 41, 5452-5463 

(2007).

S. B. McLaughlin, M. Nosal, S. D. 

Wullschleger, and G. Sun, Interactive eff ects 

of ozone and climate on tree growth and 

water use in a southern Appalachian forest 

in the USA, New Phytologist 174: 109-124 

(2007).

S. B. McLaughlin, S. D. Wullschleger, G. Sun, 

and M. Nosal, Interactive eff ects of ozone

and climate on water use, soil moisture 

content and streamfl ow in a southern

Appalachian forest in the USA. New 

Phytologist 174: 125-136 (2007).

Ralph J. Valente, Catherine Shea, K. Lynn 

Humes, Roger L. Tanner, Atmospheric

mercury in the Great Smoky Mountains 

compared to regional and global levels,

Atmospheric Environment, 41, 1861-1873 

(2007).
 34

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.

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, 19971).

W126 – A cumulative index that is 

calculated as the sum of all hourly 

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.

N100 – The number of hours with 

ozone concentrations greater than or 

equal to 0.10 ppm (100 ppb). This index 

is reported without units. The N100 

index is often considered along with the 

W126 in assessing the possible impact 

of the exposure. Several thresholds have 

been developed for W126 and N100 

(Lefohn et al, 19972).

Table 10 presents the ozone exposure 

indices summary statistics for 2006. 

Summaries for POMS are included for 

reference only. Since portable sites are 

deployed for seasonal use, there may 

be signifi cant biases in SUM06, W126, 

and N100 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 2006 there were no POMS sites that 

operated for less than three months.

•

•

•

The map in Figure 12 presents the annual 

3-month maximum SUM06 exposure index 

for all network sites listed in Table 10. 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 SUM06 

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 evaluating risk to vegetation from ozone, 

it is useful to consider not only the SUM06 

but also the W126 and N100 exposures. 

If more than one exposure index is above 

the threshold for eff ects, the potential for 

injury increases. The SUM06 risk and W126 

thresholds are relative and not absolute.

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://www2.nature.nps.gov/air/pubs/

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

http://www2.nature.nps.gov/air/pubs/pdf/

baltfi nalreport1.pdf.

References

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

Need for a Long-Term Cumulative Secondary 

Ozone Standard – An Ecological Perspective. 

Environmental Management. January.

2 Lefohn, A.S., W. Jackson, D. Shadwick, 

and H.P. Knudsen. 1997. Eff ect of Surface 

Ozone Exposures on Vegetation Grown 

in the Southern Appalachian Mountains: 

Identifi cation of Possible Areas of Concern. 

Atmospheric Environment 31(11):1695-1708.

SUM06 thresholds

No risk

to ozone sensitive vegetation

0-7 ppm-hr

Higher risk

to ozone sensitive vegetation

8-16 ppm-hr

Highest risk

to ozone sensitive vegetation

>16 ppm-hr

W126 / N100 Thresholds

Highly Sensitive Species 

Moderately Sensitive Species 

Low Sensitive Species

 W126

 5.9 ppm-hr

23.8 ppm-hr

66.6 ppm-hr

N100

 6

 51

135
35

Table 10. Summary of indices for resource injury (SUM06, W126, and N100).

National Park Unit Site Name

O3%

Valid

SUM06a

(ppm-hr)

W126b

(ppm-hr) N100c

Sites operated by the National Park Service

Badlands Visitor Center 98.9 19.3 31.2 0

Big Bend K-Bar Ranch Road 99.1 20.6 32.3 0

Canyonlands Island in the Sky 99.2 41.4 57.1 0

Chiricahua Entrance Station 97.8 28.7 41.1 0

Craters of the Moond Visitor Center --- --- --- ---

Death Valley Park Village 98.4 69.4 78.5 0

Denali Headquarters 98.8 0.4 10.2 0

Glacier West Glacier Horse Stables 98.2 0.1 7.0 0

Grand Canyon The Abyss 99.6 64.2 71.9 0

Great Basin Maintenance Yard 97.5 32.1 47.9 0

Great Smoky Mountains Clingmans Dome 98.1 69.9 72.2 1

Great Smoky Mountains Cove Mountain 99.3 64.2 81.4 0

Great Smoky Mountains Look Rock 98.9 64.7 82.5 0

Joshua Tree Black Rock 96.4 127.4 144.8 84

Joshua Tree Cottonwood Canyon 74.8 34.0 60.5 1

Lassen Volcanic Manzanita Lake Fire Station 98.1 30.6 41.8 0

Mammoth Cave Houchin Meadow 99.7 19.1 28.5 0

Mesa Verde Resource Management Area 99.1 54.9 67.7 0

Mount Rainier Tahoma Woods 97.6 5.8 8.6 0

North Cascades Marblemount Ranger Station 97.5 1.0 3.4 0

Petrifi ed Forest South Entrance 97.2 34.0 40.7 0

Pinnacles SW of East Entrance Station 99.2 25.1 31.1 2

Rocky Mountain Long’s Peak 96.3 30.7 58.7 3

Sequoia and Kings Canyon Ash Mountain 90.9 109.2 110.7 92

Sequoia and Kings Canyon Lower Kaweah 97.9 98.4 96.1 35

Shenandoah Big Meadows 91.9 43.5 58.9 0

Voyageurs Sullivan Bay 91.0 4.9 14.7 0

Yellowstone Water Tank 97.4 21.8 44.3 0

Yosemite Turtleback Dome 88.3 74.8 86.2 1

Zion Dalton’s Wash 98.6 49.5 51.6 4

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 99.4 23.9 26.4 3

Acadia McFarland Hill 99.1 10.2 19.3 0

Cape Cod Cape Cod 97.4 25.9 32.1 11

Chamizal Chamizal 98.8 18.7 25.9 10

Congaree Congaree Bluff 97.9 17.3 21.2 0

Cowpens State Monitor 99.3 20.2 31.4 2

Great Smoky Mountains Cades Cove 98.5 21.6 26.4 0

Great Smoky Mountains Purchase Knob 92.4 32.5 37.7 0

Saguaro Pima County 99.4 29.8 44.3 0

Theodore Roosevelt Painted Canyon Visitor Center 99.5 6.0 20.5 0

Wind Cave Visitor Center 99.6 27.0 49.3 0

Nearby sites operated by other agencies

Alabama-Coushatta CASTNet Site 90.9 6.9 14.5 0
 36

Table 10. Summary of indices for resource injury (SUM06, W126, and N100) (continued).

National Park Unit Site Name

O3%

Valid

SUM06a

(ppm-hr)

W126b

(ppm-hr) N100c

Nearby sites operated by other agencies

Appalachian Trail Mount Greylock Summit 92.2 20.6 25.6 0

Blue Ridge Parkway 7510 Blue Ridge Parkway 92.9 12.4 14.4 0

Blue Ridge Parkway Barnet Knob Firetower Road 90.4 69.2 53.7 0

Blue Ridge Parkway Blue Ridge Parkway 92.2 4.6 9.9 0

Blue Ridge Parkway Frying Pan Mountain 92.7 48.3 47.8 1

Blue Ridge Parkway Route 191 99.9 11.8 17.2 0

Blue Ridge Parkway Ranger Station 98.5 10.5 14.0 0

Blue Ridge Parkway Vinton Elementary 99.2 21.1 27.5 0

Boston Harbor Islands Former Nike Missile Site 95.5 16.3 18.3 0

Cuyahoga Valley 800 Patterson 99.9 19.8 22.2 0

Everglades Cutler Road 99.5 13.6 19.4 4

George Washington Pkwy Alexandria Health 96.3 27.5 27.3 18

Guilford Courthouse Mendenhall Middle School 94.9 29.2 30.1 4

Indiana Dunes Ammunition Bunker 98.9 10.5 12.6 0

Indiana Dunes Gas Station 99.2 12.0 15.5 0

Indiana Dunes Water Treatment Plant 99.7 11.8 14.6 0

Mississippi Anoka County Airport 91.1 7.4 11.1 0

Mississippi Somerset Town Hall 99.0 9.7 14.8 0

Mississippi Washington County 99.8 9.1 13.8 0

Petroglyph Westside Taylor Ranch 99.0 28.0 32.9 0

Rock Creek Achbold Parkway 99.6 25.1 26.3 5

Saratoga Stillwater 75.3 10.1 14.9 0

Saugus Iron Works Lynn Water Treatment 94.6 14.5 19.4 0

Portable ozone monitoring systems

Abraham Lincoln Birthplace Visitor Center 74.7 19.9 17.2 0

Assateague Island Maintenance Area 97.3 36.1 40.6 0

Carlsbad Caverns Maintenance Area 99.6 19.7 21.5 0

Colorado Maintenance Yard 99.4 48.3 43.8 0

Cumberland Gap Hensley Settlement 99.0 25.0 31.6 0

Dinosaur West Entrance Housing 98.6 19.4 28.1 0

Joshua Tree Pinto Wells 85.7 65.5 52.1 1

Lake Mead Meadview 73.0 85.7 71.5 0

Mount Rainier White River --- --- --- ---

Natchez Trace Parkway Dancy Ranger Station 99.4 11.3 12.5 0

Olympic Hurricane Ridge Portable 89.3 1.1 4.6 0

Padre Island Malaquite Visitor Center 88.8 18.7 20.3 0

Yosemite School Yard 99.9 16.9 13.3 0

a 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.

b W126 exposure index represents the sum of all 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. Units are ppm-hr. For more information on the W126 exposure index go to http://www2.nature.nps.gov/air/maps/

AirAtlas/docs/air_quality_glossary.pdf.

c N100 represents the number of hourly ozone concentrations greater than or equal to 0.100 ppm (100 ppb).

d Ozone data at Craters of the Moon were invalid in 2006 due to a leak that was found in the inlet tubing in Spring 2007. The leak was caused during roof replacement at the 

visitor center in Winter 2004. Note: Dashed lines represent no data available for 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
37

Figure 12. Annual 3-month maximum SUM06 exposure index.

Great Smoky Mountains (5)

Abraham Lincoln Birthplace

Badlands

Big Bend

Canyonlands

Carlsbad Caverns

Chamizal Chiricahua

Colorado NM

Congar

Cowpens

Craters of the Moon

Cumberland

Gap

Denali

Death Valley

Dinosaur

Glacier

Great Basin

Grand Canyon

Joshua Tree

Lake Mead

Lassen Volcanic

Mammoth Cave

Mesa Verde

Mount Rainier

Natchez Trace

Olympic North Cascades

Padre Island

Petrified Forest

Pinnacles

Rocky Mountain

Saguaro

Sequoia/Kings Canyon (2)

Shenan

Theodore Roosevelt

Voyageurs

Wind Cave

Yellowstone

Yosemite

Zion

Appalachian 

Blue 

Blue Ridge Parkway (south unit) (5)

Cuyahoga Vall

Gu

Indiana Dunes (3)

Mississippi (3)

Petroglyph

Sa

Alabama-Coushatta

20

19

21

41

20 19 29

48

17

20

25

0

69

19

0

32

64

70

127

86

31

19

55

6

11

1 1

19

34

25

31

30

109

44

6

5

27

22

75

50

21

69

20

29

28

12

10

28

2

14

7

N/A

* 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-hr

> 16 ppm-hr

Portable site
 38

Sulfur Dioxide Data Summaries

Sulfur dioxide (SO2) is a criteria pollutant 

that over time undergoes chemical 

transformations in the atmosphere 

to form aqueous 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 11 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.

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 999 ppb, 

but is considered to be an EPA equivalency 

method. The upper range captures values 

above 999 ppb accurately, but is not an EPA 

reference method. 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 National Park, 

Hawaii

Pu `u `O `o After the Collapse

June 25, 2007

Photograph by Greg Funderburk/NPS
39

Table 11. 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 ServiceGreat Smoky Mountains Cove Mountain 1 6 5 5 5 0 23 21 15 13 0 Hawaii Volcanoes * Observatory 24 292 239 224 173 11 1001 981 637 624 6 Hawaii Volcanoes * Visitor Center 18 452 255 178 171 7 1507 1026 999 938 4 Shenandoah * Big Meadows 1 10 6 4 4 0 17 15 14 14 0 Sites operated by cooperating state agenciesBadlands Visitor Center 1 2 2 2 2 0 10433 0 

Congaree Congaree Bluff 1 17 9 8 8 0 60 47 46 32 0 Theodore Roosevelt Painted Canyon Visitor Ctr 0 2 2 2 2 0 8 7 6 6 0 Wind Cave Visitor Center 1 3 3 3 2 0 8866 0 Nearby sites operated by other agenciesBlue Ridge Parkway Vinton Elementary 2 13 10 10 8 0 23 20 19 19 0 George Washington Pkwy Alexandria Health 3 36 17 14 12 0 67 46 46 35 0 Indiana Dunes Gas Station 3 17 9 9 9 0 31 29 24 24 0 Mississippi Anoka County Airport 0 5 4 4 3 0 14 14 14 10 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 stab 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

292

1026 999 938

981 637 624

15071001

171

173

178224

255

239

452
 40

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. Acidic particulate matter 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 65 μg/m3. 

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 65 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 65 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 12 summarizes PM2.5 measurements 

with respect to both the daily 24-hour 

average maximum concentrations and the 

annual arithmetic mean. Since none of 

the PM2.5 monitors at these sites are EPAcertifi ed, these comparisons are made for 

reference purposes only. 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 65μg/m3. 

No violation summaries for PM2.5 data are 

presented.

North Cascades National Park, 

Washington

NPS stock photo
41

Table 12. 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

>65 μg/m3

Sites operated by the National Park Service

Badlands Visitor Center BAM 97.8 3.5 15 14 13 13 12 0

Great Smoky Mountains Look Rock TEOM 97.8 13.8 43 42 41 39 32 0

Shenandoah Big Meadows TEOM 93.3 11.5 37 36 35 34 32 0

Yellowstone Old Faithful BAM 98.7 5.0 33 28 24 22 13 0

Sites operated by cooperating state agencies

Acadia McFarland Hill TEOM 98.7 4.3 30 25 23 20 17 0

Theodore Roosevelt Painted Canyon Visitor Ctr TEOM 98.5 5.8 34 24 23 21 15 0

Wind Cave Visitor Center BAM 97.1 3.8 28 19 18 15 11 0

Yosemite Village BAM 91.8 13.5 36 34 33 30 29 0

Nearby sites operated by other agencies

Guilford Courthouse Mendenhall Middle School TEOM 96.0 15.7 42 42 41 36 35 0

Mississippi Anoka County Airport BAM 96.8 8.3 31 30 28 28 24 0

Petroglyph Westside Taylor Ranch BAM 98.9 7.0 30 30 26 24 21 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 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 65 μg/m3. (An exceedance of the standard occurs when a 24-hour 

average PM2.5 concentration is greater than 65 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 65 μg/m3.) (40 CFR 50.7.)

* TEOM = tapered element oscillating microbalance

 BAM = beta attenuation monitor 
 42

PM10 Data Summaries

Table 13 summarizes PM10 measurements 

with respect to both the daily 24-hour 

average maximum concentrations and 

the annual arithmetic mean at each EPAcertifi ed monitoring site. 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 14 presents the same summaries 

for sites that collected PM10 using nonequivalency methods.

 

Table 15 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 requirement 

are included in the NAAQS violation 

computation if the resulting 24-hour average 

exceeds the standard.

Glacier National Park, Montana

NPS stock photo
43

Table 13. Summary of PM10 data from reference and equivalency methods.

National Park Unit Site Name

Sampler

Type*

%

Valida

Annual Arithmetic

Mean (μg/m3)

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

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of Days with 

24-Hour Average

>65 μg/m3

Sites operated by cooperating state agencies

Badlands Visitor Center BAM 98.9 9 30 30 30 30 0

Wind Cave Visitor Center BAM 98.9 7 30 30 20 20 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 

per year on average over three years.) (40 CFR 50.6.)

* TEOM = tapered element oscillating microbalance

 BAM = beta attenuation monitor 

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

italics = site operated by a state agency 

Table 15. PM10 summary - daily standard (μg/m3)

a.

National Park Unit Site Name Sampler Type* 2006 2005 2004

Sites operated by cooperating state agencies

Badlands Visitor Center BAM 30 40 ---

Wind Cave Visitor Center BAM 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 

per year on average over three years.) (40 CFR 50.6.)

* TEOM = tapered element oscillating microbalance

 BAM = beta attenuation monitor 

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

Color shading key: > 1 24-hour average concentration >50 μg/m3

italics = site operated by a state agency

 

Table 14. Summary of PM10 data from non-equivalency methods.

National Park Unit Site Name

Sampler

Type

%

Valid

Annual Arithmetic

Mean (μg/m3)

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

1st

Highest

2nd

Highest

3rd

Highest

4th

Highest

No. of Days with 

24-Hour Average

>65 μg/m3

Sites operated by the National Park Service

Joshua Tree Cottonwood Canyon E-sampler 53.1 2 20 10 10 10 0
 44

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.

Table 16 presents a summary of selected 

meteorological data for all sites. The 

parameters included are wind speed, 

ambient temperature, relative humidity, 

and precipitation.

Colorado National Monument, 

Colorado

NPS stock photo
45

Table 16. 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 11.2 44.3 -27.0 56 100 3 77.8

Big Bend K-Bar Ranch Road 3.5 21.3 37.6 -3.5 36 99 3 276.2

Canyonlands Island in the Sky 2.9 12.1 35.4 -11.0 39 99 4 189.2

Chiricahua Entrance Station 3.1 16.0 36.1 -7.0 41 100 5 292.5

Craters of the Moon Visitor Center 3.3 6.4 34.9 -21.2 54 100 8 ---

Death Valley Park Village 3.7 25.9 48.5 5.3 18 93 2 40.0

Denali Headquarters 1.4 -2.3 23.0 -35.9 69 98 18 228.3

Everglades Beard Center 2.2 22.7 32.4 4.4 80 100 24 1106.7

Glacier West Glacier Horse Stables 0.9 8.6 34.4 -19.9 73 100 13 712.3

Grand Canyon The Abyss 2.8 10.9 31.9 -10.6 40 99 3 323.3

Great Basin Maintenance Yard 2.8 9.2 33.8 -16.0 42 96 4 268.3

Great Smoky Mountains Clingmans Dome 3.8 10.8 20.3 -15.0 89 100 3 1224.5

Great Smoky Mountains Cove Mountain 4.8 11.2 26.9 -16.2 71 100 2 1206.5

Great Smoky Mountains Look Rock 2.5 13.4 30.1 -12.9 68 100 15 1113.0

Hawaii Volcanoes Observatory 4.9 16.1 25.4 7.6 87 100 11 1888.8

Hawaii Volcanoes Visitor Center 3.7 15.7 26.5 7.4 92 100 37 2798.1

Joshua Tree Black Rock 3.0 16.3 36.8 -3.4 31 94 2 98.8

Joshua Tree Cottonwood Canyon 3.6 19.8 39.6 -1.6 27 100 3 6.0

Lassen Volcanic Manzanita Lake Fire Station 2.0 7.0 31.5 -14.3 61 98 6 1025.4

Mammoth Cave Houchin Meadow 1.8 14.4 35.1 -13.1 71 100 18 1273.9

Mesa Verde Resource Management Area 2.9 10.4 32.1 -13.6 40 98 4 310.1

Mount Rainier Tahoma Woods 1.1 8.9 34.5 -10.4 82 100 12 1809.5

North Cascades Marblemount Ranger Station 1.4 9.7 36.5 -5.1 76 100 5 2248.0

Petrifi ed Forest South Entrance 4.2 12.8 34.2 -13.5 39 99 3 157.4

Pinnacles SW of East Entrance Station 2.2 13.9 43.6 -6.5 63 98 4 376.9

Rocky Mountain Long’s Peak 2.9 4.4 25.8 -25.1 49 99 5 412.8

Sequoia and Kings Canyon Ash Mountain 2.5 16.7 40.8 -0.8 53 100 9 468.5

Sequoia and Kings Canyon Lower Kaweah 1.7 9.1 29.0 -11.7 61 100 3 715.7

Shenandoah Big Meadows 2.6 9.0 27.2 -19.5 71 100 8 1326.6

Voyageurs Sullivan Bay 2.7 4.6 32.6 -30.1 70 100 9 520.2

Yellowstone Old Faithful 1.8 2.3 30.0 -34.3 67 100 8 ---

Yellowstone Water Tank 1.7 1.7 27.8 -29.4 65 98 10 438.9

Yosemite Turtleback Dome 4.0 10.8 32.4 -9.4 52 100 6 878.6

Zion Dalton’s Wash 3.0 16.2 40.5 -8.3 34 99 1 201.7

Sites operated by cooperating state agencies

Acadia Cadillac Mountain 6.4 13.0 27.8 -2.5 85 100 19 ---

Acadia McFarland Hill 3.3 8.2 30.1 -18.8 75 100 25 1280.1

Cape Cod Cape Cod 2.6 10.5 33.9 -12.2 82 100 22 ---

Chamizal Chamizal 3.3 19.6 39.3 -3.3 34 96 3 ---

Great Smoky Mountains Cades Cove 1.3 13.8 33.5 -12.1 76 100 16 1366.4

Saguaro Pima County 2.5 21.6 41.4 -0.9 28 97 1 ---

Theodore Roosevelt Painted Canyon Visitor Center 5.2 8.3 38.7 -30.1 60 100 9 200.3

Wind Cave Visitor Center 3.0 12.3 37.6 -18.7 47 97 6 214.0
 46

Table 16. 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 2.1 19.5 34.9 -3.3 75 100 14 1555.9

Blue Ridge Parkway 7510 Blue Ridge Parkway --- 10.4 30.6 -13.7 84 100 15 ---

Blue Ridge Parkway Ranger Station --- 12.3 34.7 -12.1 69 99 10 ---

Boston Harbor Islands Former Nike Missile Site 3.2 10.1 34.9 -12.1 77 100 30 ---

Guilford Courthouse Mendenhall Middle School 1.4 15.8 35.0 -7.9 70 95 16 919.8

Indiana Dunes Ammunition Bunker 3.7 8.0 33.9 -19.2 70 100 20 ---

Indiana Dunes Gas Station 3.4 11.3 34.3 -16.5 --- --- --- ---

Mississippi Somerset Town Hall 2.3 --- --- --- --- --- --- ---

Petroglyph Westside Taylor Ranch --- 13.4 36.4 -8.3 --- --- --- ---

Saugus Iron Works Lynn Water Treatment 2.6 10.6 35.9 -15.1 64 91 7 56.3

Portable ozone monitoring systems

Abraham Lincoln Birthplace Visitor Center 0.5 21.4 35.5 5.0 76 96 27 624.0

Assateague Island Maintenance Area 1.6 21.5 35.9 5.0 78 98 30 575.4

Carlsbad Caverns Maintenance Area 3.8 24.4 38.6 10.5 53 99 6 305.2

Colorado Maintenance Yard 1.7 22.6 38.0 1.6 31 97 5 107.5

Cumberland Gap Hensley Settlement 2.1 17.4 28.2 2.9 80 100 29 595.1

Dinosaur West Entrance Housing 1.5 18.9 39.9 -6.8 40 99 6 91.2

Joshua Tree Pinto Wells 3.2 32.8 46.0 13.6 20 74 4 0.5

Lake Mead Meadview 4.0 27.4 42.4 5.7 22 90 4 69.7

Mount Rainier White River 0.5 13.4 34.3 -0.4 68 100 11 32.4

Natchez Trace Parkway Dancy Ranger Station 0.3 24.2 39.1 4.7 74 100 21 441.0

Olympic Hurricane Ridge Portable 0.7 11.7 28.4 0.1 64 100 13 52.6

Padre Island Malaquite Visitor Center 5.9 26.9 31.9 17.6 80 97 12 356.5

Yosemite School Yard 0.8 19.6 36.2 1.3 52 97 11 35.3

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
47

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 U.S. Department of the Interior (DOI) is the nation’s principal conservation agency, charged 

with the mission “to protect and provide access to our Nation’s natural and cultural heritage and 

honor our trust responsibilities to Indian tribes and our commitments to island communities”. 

More specifi cally, Interior protects America’s treasures for future generations, provides access 

to our nation’s natural and cultural heritage, off ers recreation opportunities, honors its trust 

responsibilities to American Indians and Alaska Natives and its responsibilities to island 

communities, conducts scientifi c research, provides wise stewardship of energy and mineral 

resources, fosters sound use of land and water resources, and conserves and protects fi sh and 

wildlife. The work that we do aff ects the lives of millions of people; from the family taking a vacation 

in one of our national parks to the children studying in one of our Indian schools. 

NPS D-1883, October 2007
 EXPERIENCE YOUR AMERICATM

 Natural Resource Program Center

 Air Resources Division

P.O. Box 25287

 Denver, CO 80225-0287

 www2.nature.nps.gov/air

National Park Service

 U.S. Department of the Interior

 Natural Resource Program Center

 Air Resources Division