E M PAC T

Environmental Monitoring for Public Access 

& Community Tracking

United States Office of Research and EPA/625/R-99/007

Environmental Protection Development September 1999

Agency Washington, DC 20460 http://www.epa.gov/empact

Ozone Monitoring, Mapping,

and Public Outreach

Delivering Real-Time Ozone

Information to Your Community

1EPA
Disclaimer

This document has been reviewed by the U.S. Environmental Protection Agency (EPA) and approved for publication.

Mention of trade names or commercial products does not constitute endorsement or reccommendation of their use.
EPA/625/R-99/007

September 1999

Ozone Monitoring, Mapping,

and Public Outreach

Delivering Real-Time Ozone

Information to Your Community

United States Environmental Protection Agency

National Risk Management Laboratory

Office of Research and Development

Cincinnati, Ohio 45268

2Printed on paper containing at least 30% postconsumer recovered fiber.
ACKNOWLEDGMENTS

The development of this handbook was managed by Scott Hedges (U.S. Environmental Protection Agency,

National Risk Management Laboratory) with technical guidance from Richard Wayland (U.S. Environmental

Protection Agency, Office of Air Quality, Planning and Standards). While developing this handbook, we sought

the input of many individuals in air quality agencies across the country and within the U.S. Environmental

Protection Agency. Gratitude is expressed to each person for their involvement and contributions. 

Tad Aburn, Maryland Department of the Environment, Air Quality Planning Program

Lee Alter, Northeast States for Coordinated Air Use Management (NESCAUM) 

Aaron Childs, City of Indianapolis Environment and Resource Management Division

Greg Cooper, New Jersey Department of Environmental Protection, Office of Air Quality Management

Laura DeGuire, Michigan Department of Environmental Quality, Air Quality Division

Phil Dickerson, U.S. Environmental Protection Agency, Office of Air Quality, Planning and Standards

Tim Dye, Sonoma Technology, Inc.

Chris Galilei, Ohio Environmental Protection Agency

Lisa Grosshandler, North Carolina Department of the Environment and Natural Resources, Division of Air

Quality

Mike Koerber, Lake Michigan Air Directors Consortium (LADCO)

Thomas Monosmith, Michigan Department of Environmental Quality, Air Quality Division

Randy Mosier, Maryland Department of the Environment, Air Quality Planning Program

Mike Norcom, Mississippi Department of Environmental Quality

James Parks, Indiana Department of Environmental Management, Air Quality Division

Charles Pietarinen, New Jersey Department of Environmental Protection, Office of Air Quality Management

Scott Reynolds, South Carolina Department of Health and Environmental Control, Air Quality Analysis

Mike Rizzo, U.S. Environmental Protection Agency, Region 5

Liz Santa, Louisiana Department of Environmental Quality, Air Quality Division

Kerry Shearer, Sacramento Metropolitan Air Quality Management District

Dan White, Texas Natural Resource Conservation Commission

Neil Wheeler, MCNC Environmental Programs
CONTENTS

1. INTRODUCTION 1

2. HOW TO USE THIS HANDBOOK 5

3. OZONE MONITORING 7

3.1 Ozone Monitoring—An Overview 7

3.2 Siting Your Ozone Monitoring Network 10

3.3 Selecting Monitoring Equipment 13

3.4 Installing Monitoring Equipment 15

3.5 Calibrating Monitoring Equipment 18

3.6 Maintaining Your Monitoring Equipment and Ensuring Data Quality 20

3.7 Annual Network Review 24

4. DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 25

4.1 Overview of the Automated Data Transfer System (ADTS) 25

4.2 Getting Ready to Use the ADTS for Data Collection and Transfer 28

4.3 Using the ADTS for Data Collection and Transfer 32

4.4 Operations at the Data Collection Center 41

5. MAKING OZONE MAPS 45

5.1 Understanding MapGen’s Capabilities 45

5.2 Getting Started 46

5.3 Generating and Managing Maps 48

5.4 Advanced Features 61

5.5 Technical Support 61

6. COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 63

6.1 Creating an Outreach Plan for Ozone 63

6.2 Successful Ozone Outreach Programs 70

6.3 Guidelines for Presenting Information About Ozone to the Public 71

APPENDIX A A-1

Tips on Configuring the Automatic Data Transfer System

APPENDIX B B-1

Instructions for Installing and Configuring Software

APPENDIX C C-1

Automated Data Quality Checks

1. INTRODUCTION

O

zone, when it occurs at ground level, presents a serious air quality problem

in many parts of the United States. Ozone is a major ingredient of smog, and

when inhaled—even at very low levels—it can cause a number of respiratory health effects. People who live in communities with high ozone levels can use

timely and accurate information to make informed decisions about how to protect their health from ozone exposure and when to take actions to reduce local

ozone levels. 

This handbook is designed to provide you with step-bystep instructions about how to provide this information

to your community. It was developed by the U.S.

Environmental Protection Agency’s (EPA’s) EMPACT

program. EPA created EMPACT (Environmental

Monitoring for Public Access and Community Tracking)

in 1997, at President Clinton’s direction. The program

takes advantage of new technologies that make it possible

to provide environmental information to the public in

near real time. EMPACT is working with the 86 largest

metropolitan areas of the country to help communities in

these areas:

! Collect, manage, and distribute time-relevant environmental information.

! Provide their residents with easy-to-understand information they can use in making informed, day-to-day

decisions.

To help make EMPACT more effective, EPA is partnering with the National

Oceanic and Atmospheric Administration and the U.S. Geological Survey. EPA

will work closely with these federal agencies to help achieve nationwide consistency in measuring environmental data, managing the information, and delivering it to the public. 

To date, environmental information projects have been initiated in 61 of the 86

EMPACT-designated metropolitan areas. These projects cover a wide range of

environmental issues, such as groundwater contamination, ocean pollution,

smog, ultraviolet radiation, and overall ecosystem quality. Some of these projects

have been initiated directly by EPA. Others have been launched by EMPACT

communities themselves. Local governments from any of the 86 EMPACT metropolitan areas are eligible to apply for EPA-funded Metro Grants to develop their

own EMPACT projects. 

The 86 EMPACT metropolitan areas are listed in the table at the end of this

chapter.

Communities selected for Metro Grant awards are responsible for building their

own time-relevant environmental monitoring and information delivery systems.

INTRODUCTION 1

Ozone occurs both in the Earth’s upper atmosphere and at ground

level. Ozone can be good or bad, depending on where it is found:

GOOD OZONE BAD OZONE

Ozone occurs naturally in the

Earth’s upper atmosphere—

10 to 30 miles above the Earth’s

surface—where it forms a 

protective barrier that shields

people from the sun’s harmful

ultraviolet rays. This barrier is

sometimes called the “ozone

layer. “

Because of pollution, ozone can

also be found in the Earth’s

lower atmosphere, at ground

level. Ground-level ozone is 

a major ingredient of smog,

and it can harm people’s

health by damaging their

lungs. Ground-level ozone can

also damage crops and many

common man-made materials,

such as rubber, plastic, and

paint.
To find out how to apply for a Metro Grant, visit the EMPACT Web site at

http://www.epa.gov/empact/apply.htm.

One of the largest and most successful EMPACT projects is the Ozone Mapping

Project, which creates maps that provide communities with real-time information

about ozone pollution in an easy-to-understand pictorial format. The maps are

created from hourly ozone data taken from monitoring networks in different

regions of the country. They use color-coded contours to depict the level of health

concern associated with different categories of ozone concentration. Shown below

is a map that depicts peak ozone values in the northeastern United States on

August 24, 1998.

The Ozone Mapping Project is a cooperative effort of the EPA, State and local air

pollution control agencies, and regional organizations, including the Northeast

States for Coordinated Air Use Management (NESCAUM)(http://www.

nescaum.org), the Mid-Atlantic Regional Air Management Association 

(MARAMA)(http://www.marama.org), and the Lake Michigan Air Directors

Consortium (LADCO)(http://www.ladco.org). In 1998, EPA’s Office of Air and

Radiation assumed coordination of the project. The ozone maps are found on

EPA’s AIRNOW Web site—part of the Ozone Mapping Project

(http://www.epa.gov/airnow). AIRNOW displays still-frame maps that show

today’s ozone levels, yesterday’s peak ozone values, and tomorrow’s ozone forecast,

2 CHAPTER 1
as well as animated maps that depict the formation and movement of ozone

throughout the day. The AIRNOW Web site also provides information about the

health effects of ozone and links to state and local air pollution control agencies with

real-time ozone data. 

The number of cities served by the Ozone Mapping Project is growing but limited by available resources. The Technology Transfer and Support Division of the

EPA Office of Research and Development’s (ORD’s) National Risk Management

Laboratory initiated the development of this handbook to help interested communities learn more about the Ozone Mapping Project and to provide them with

the technical information they need to develop and manage their own ozone

monitoring, mapping, and information dissemination programs. ORD, working

with the AIRNOW project lead from EPA’s Office of Air Quality, Planning and

Standards, produced the handbook to maximize EMPACT’s investment in the

project and minimize the resources needed to implement it in new cities. The

handbook is also available in CD-ROM format.

Both print and CD-ROM versions of the handbook are available for direct online ordering from EPA’s Office of Research and Development Technology

Transfer Web site at http://www.epa.gov/ttbnrmrl/. The handbook can be

downloaded from EPA’s Office of Air Quality Planning and Standards AIRNOW

Web site at http://www.epa.gov/airnow/. You can also obtain a copy of the

handbook by contacting the EMPACT program office at:

EMPACT Program 

U.S. EPA (8722R)

401 M Street, SW

Washington, DC 20460

Phone: 202-564-6791

Fax: 202-565-1966 

We hope that you find the handbook worthwhile, informative, and easy to use.

We welcome your comments, and you can send them by e-mail from EMPACT’s

Web site at http://www.epa.gov/empact/comment.htm.

INTRODUCTION 3
4 CHAPTER 1

Albany-Schenectady-Troy, NY

Albuquerque, NM

Allentown-Bethlehem-Easton, PA

Anchorage, AK

Atlanta, GA

Austin-San Marcos, TX

Bakersfield, CA

Billings, MT

Birmingham, AL

Boise, ID 

Boston, MA-NH

Bridgeport, CT

Buffalo-Niagara Falls, NY

Burlington, VT

Charleston-North Charleston, SC

Charleston, WV

Charlotte-Gastonia-Rock Hill, NCSC

Cheyenne, WY

Chicago-Gary-Kenosha, IL-IN-WI

Cincinnati-Hamilton, OH-KT-IN

Cleveland-Akron, OH

Columbus, OH

Dallas-Fort Worth, TX

Dayton-Springfield, OH

Denver-Boulder-Greeley, CO

Detroit-Ann Arbor-Flint, MI

El Paso, TX

Fargo-Moorhead, ND-MN

Fresno, CA 

Grand Rapids-Muskegon-Holland,

MI

Greensboro-Winston Salem-High

Point, NC

Greenville-Spartanburg-Anderson,

SC

Harrisburg-Lebanon-Carlisle, PA

Hartford, CA

Honolulu, HI

Houston-Galveston-Brazoria, TX

Indianapolis, IN

Jackson, MS

Jacksonville, FL

Kansas City, MO-KS

Knoxville, TN

Las Vegas, NV

Little Rock-North Little Rock, AR

Los Angeles-Riverside-Orange

County, CA

Louisville, KY-IN

Memphis, TN-AR-MS

Miami-Fort Lauderdale, FL

Milwaukee-Racine, WI

Minneapolis-St. Paul, MN

Nashville, TN

New Orleans, LA

New York-Northern New JerseyLong Island, NY-NJ-CT-PA

Norfolk-Virginia Beach-Newport

News, VA-NC

Oklahoma City, OH

Omaha, NE-IA

Orlando, FL

Philadelphia-Wilmington-Atlantic

City, PA-NJ-DE-MD

Phoenix-Mesa, AZ

Pittsburgh, PA

Portland, ME

Portland-Salem, OR-WA

Providence-Fall River-Warwick, RIMA

Raleigh-Durham-Chapel Hill, NC

Richmond-Petersburg, VA

Rochester, NY

Sacramento-Yolo, CA

Salt Lake City-Ogden, UT

San Antonio, TX

San Diego, CA

San Francisco-Oakland-San Jose,

CA

San Juan, PR

Scranton-Wilkes-Barre-Hazleton, PA

Seattle-Tacoma-Bremerton, WA

Sioux Falls, SD

Springfield, MA

St. Louis-E. St. Louis, MO-IL

Stockton-Lodi, CA

Syracuse, NY 

Tampa-St. Petersburg-Clearwater, FL

Toledo, OH

Tucson, AZ

Tulsa, OK

Washington-Baltimore, DC-MD-VAWV

West Palm Beach-Boca Raton, FL

Wichita, KS

Youngstown-Warren, OH

EMPACT Metropolitan Areas 
2. HOW TO USE 

THIS HANDBOOK

T

his handbook provides you with the information your community will need

to develop an ozone monitoring, mapping, and outreach program. It contains

detailed guidance about how to:

The handbook provides simple “how-to” instructions on each of these topics:

! Chapter 3 explains how to implement an ozone monitoring program

that will meet criteria established under the Clean Air Act for a

National Air Monitoring Station and State/Local Air Monitoring

Station (NAMS/SLAMS) monitoring network. It helps you plan and

site your ozone monitoring network; select, install, and operate your

monitoring equipment; and develop a preventive maintenance plan. 

! Chapter 4 provides you with the information you will need to operate

the Automatic Data Transfer System (ADTS), which retrieves data from

ozone monitors, converts the data from a participating agency’s format

to a standard format, ensures the integrity of the data, and prepares it

for ready-to-use mapping. This chapter helps you to obtain, install,

configure, and operate the ADTS. It also provides guidance on how to

conduct quality assurance checks on your ozone data. Appendices A

and B provide step-by-step instructions on how to configure the ADTS

and install supplemental software, and Appendix C contains a detailed

description of data quality checks. 

! Chapter 5 offers a complete primer on MapGen, a software application developed by EPA that you can use to make maps that illustrate

the concentration levels of ozone in your area. This chapter contains

instructions on obtaining and installing the software, generating maps,

using advanced features, troubleshooting, and obtaining technical support.

! Chapter 6 outlines the steps involved in developing an ozone outreach plan and profiles examples of successful ozone outreach initiatives

that have been implemented in EMPACT cities across the country. It

also provides guidelines for communicating information about ozone

and includes examples of information, written in an easily understandable, plain-English style, which you can incorporate into your own

communication and outreach materials.

HOW TO USE THIS HANDBOOK 5

Design, site, operate, 

and maintain an ozone

monitoring system.

Develop, operate, and 

maintain a system to

retrieve, manage, and 

distribute real-time ozone

data.

Use these data to create

ozone maps that graphically

depict information, in near

real time, about ozone 

concentrations in your area.

Develop a program to 

communicate information

about real-time ozone levels

and the health effects of ozone

to people in your community.
This handbook is designed both for decision-makers who may be considering

whether to implement an ozone program in their communities and for technicians responsible for implementing an ozone program. Managers and decisionmakers likely will find the initial sections of Chapters 3, 4, and 5 most helpful.

The latter sections of these chapters are targeted primarily for technicians and

provide detailed “how to” information. Chapter 6 is designed for managers and

communication specialists.

The handbook also refers you to supplementary sources of information, such as

Web sites, EPA technical guidance documents, and Internet news groups, where

you can find additional guidance at a greater level of technical detail. Interspersed

throughout the handbook are success stories and lessons learned from EMPACT

cities that have already implemented their own ozone monitoring, data transfer,

mapping, and outreach programs.

6 CHAPTER 2
3. OZONE MONITORING

T

his chapter provides information about ozone monitoring, the first step in the

process of generating real-time ground-level ozone information and making

it available to residents in your area. The chapter begins with a broad

overview of ozone monitoring (Section 3.1), then provides information about

how to site, install, operate, and maintain an ozone monitoring network that

complies with federal regulations (Sections 3.2 through 3.7). Throughout this

chapter, you will find references to additional EPA guidance documents that provide detailed technical information about ozone monitoring. 

Readers interested primarily in an overview of ozone monitoring may want to

focus on the introductory information in Section 3.1. If you are responsible for

actual design and implementation of a monitoring network, you should review

Sections 3.2 through 3.7 for an introduction to the specific steps involved in

developing and operating an ozone monitoring network and for information on

where to find additional technical guidance.

3.1 OZONE MONITORING—AN OVERVIEW

Ground-level ozone is regulated under the Clean Air Act, the comprehensive federal law that regulates air emissions in the United States. Among other things, the

Clean Air Act requires the U.S. EPA to set standards for “criteria pollutants”—six

commonly occurring air pollutants, one of which is ground-level ozone. These

standards, known as the National Ambient Air Quality Standards (NAAQS), are

national targets for acceptable concentrations of each of the criteria pollutants.

For each pollutant, EPA has developed two NAAQS standards: 

! The “primary standard,” which is intended to protect public health.

! The “secondary standard,” which is intended to prevent damage to the

environment and property. 

A geographic area that meets the primary health-based NAAQS is called an

attainment area. Areas that do not meet the primary standard are called nonattainment areas. More information about the Clean Air Act (including the full

text of the law and a Plain English Guide to the Act) can be found at

http://www.epa.gov/epahome/laws.htm.

The Clean Air Act requires each state to develop State Implementation Plans

(SIPs). SIPs describe the programs a state will use to maintain good air quality in

attainment areas and meet the NAAQS in nonattainment areas. For example, if a

city or region is a nonattainment area for ozone, the SIP describes the programs

that will be used to meet the primary NAAQS for ozone.

One of the elements of your state’s SIP is a network of monitors that measure concentrations of the six criteria pollutants, including ozone. An ozone monitoring

network is an air quality surveillance system consisting of monitoring stations that

measure ambient concentrations of ozone. The Clean Air Act places the responsibility on states to establish and operate these ozone monitoring networks and to

report the data to EPA. EPA’s standards for ozone monitoring networks are found

OZONE MONITORING 7
in the Code of Federal Regulations (40 CFR Part 58 [National Primary and

Secondary Ambient Air Quality Standards]). You can access and review these

CFR sections from the Ambient Monitoring Technology Information Center

(AMTIC) Web site at http://www.epa.gov/ttn/amtic/codefed.html.

Information provided by your ozone monitoring network is used for a number of

purposes:

! To determine if your area is in compliance with the ozone NAAQS.

! For use in models that are used to develop strategies for controlling

ozone levels in your area.

! To provide information to the public about local air quality. You can

use ozone data to create ozone maps depicting today’s ozone levels, yesterday’s peak ozone values, and tomorrow’s ozone forecast, as well as

animated maps that illustrate the formation and movement of ozone

throughout the day. These maps serve as effective tools for warning residents in your community when levels of ozone are unhealthy or expected to be unhealthy. 

Under the State and Local Air Monitoring Stations network, three different subsystems are used to carry out ozone monitoring:

! State and Local Air Monitoring Stations (SLAMS). SLAMS stations are

used to demonstrate if an area is meeting the ozone NAAQS. A

SLAMS system consists of a carefully planned network of fixed monitoring stations, with the network size and station distribution largely

determined by the needs of state and local air pollution control agencies to meet their SIP requirements. EPA gives states and localities flexibility in determining the size of their SLAMS network based on their

data needs and available resources. SLAMS network must be able to

determine:

• The highest concentration of ozone expected to occur in the area

covered by the network.

• Representative concentrations in areas of high population density.

• The impact of significant sources or source categories on ambient

pollution levels.

• General background concentration levels.

• The extent of regional pollutant transport among populated areas.

• Impacts in more rural and remote areas (such as visibility impairment

and effects on vegetation).

! National Air Monitoring Stations (NAMS). NAMS are used to supply

data for national policy and trend analyses and to provide the public

with information about air quality in major metropolitan areas. NAMS

are required in urban areas with populations greater than 200,000.

NAMS monitoring stations are selected from a subset of the SLAMS

network, and EPA requires a minimum of two NAMS monitors in

8 CHAPTER 3
each of these metropolitan areas. There are two categories of NAMS

monitoring stations:

• Stations located in areas of expected maximum ozone concentration.

• Stations located in areas where poor air quality is combined with

high population density. (These monitors are sometimes known as

“maximum exposure monitors.”)

! Photochemical Assessment Monitoring Stations (PAMS). PAMS are

required to obtain more comprehensive and representative data about

ozone air pollution in ozone nonattainment areas designated as serious

severe, or extreme. The table below shows how EPA designates a nonattainment area as serious, severe, or extreme. (The ozone design value

for a site, shown in the right-hand column, is the 3-year average of the

annual fourth-highest daily maximum 8-hour ozone concentration.)

PAMS networks are used to monitor surface and upper-air meteorological

conditions and ozone precursors. (See the box below for an explanation

of ozone precursors.) Areas with fewer than 500,000 people must have

at least two PAMS sites; areas with 500,000 to 1,000,000 people must

have at least three sites; areas with 1,000,000 to 2,000,000 people must

have at least four sites; and areas with more than 2,000,000 people

must have at least five sites. EPA’s Photochemical Assessment Monitoring

Stations Implementation Manual (available at http://www.epa.gov/

ttnamti1/pams.html) provides detailed information about the number

of PAMS required, station location guidance, and siting criteria. The

specific types of PAMS monitoring sites are described in greater detail

in Appendix D of 40 CFR Part 58.

OZONE MONITORING 9

Serious 0.160 parts per million (ppm) to 0.180 ppm

Severe 0.180 ppm to 0.280 ppm

Extreme 0.280 ppm and higher

Nonattainment Area Classification Ozone Design Value

Ozone Precursors

Ground-level ozone forms when various pollutants, such as volatile organic compounds and nitrogen oxides, mix in the air and react chemically in

the presence of sunlight. These pollutants are known as ozone precursors.

Common sources of volatile organic compounds (often referred to as

VOCs) include motor vehicles, gas stations, chemical plants, and other

industrial facilities. Solvents such as dry-cleaning fluid and chemicals used

to clean industrial equipment are also sources of VOCs. Common sources

of nitrogen oxides include motor vehicles, power plants, and other fuelburning sources.
Because ozone levels increase significantly in the hotter parts of the year in most

areas of the country, EPA requires that ozone monitoring at NAMS and SLAMS

monitoring sites be conducted during “ozone season” only. EPA has designated

ozone seasons for each state. These designations can be found in Appendix D of

40 CFR Part 58.

3.2 SITING YOUR OZONE MONITORING NETWORK

You will need to take a series of specific steps to establish and begin operating an

ozone monitoring network. First, you will need to consider where to locate your

ozone monitors. A well-designed ozone monitoring network would likely include

monitoring stations at four key types of sites:

! Maximum population exposure sites

! Maximum downwind concentration sites

! Maximum emissions impact (maximum ozone precursor concentration)

sites

! Upwind background sites

The chart below provides details about these sites:

Locating Monitoring Sites

This subsection provides some basic information about how to locate monitoring

sites and how to site monitors to avoid problems in the immediate vicinity of the

monitor. For detailed guidance on siting ozone monitors, see Guideline on Ozone

Monitoring Site Selection (available online at http://www.epa.gov/ttn/

amtic/cpreldoc.html).

Locating Maximum Population Exposure Sites. You can use census or other population data to identify the areas with the highest populations. Ideally, the ozone

monitor should be located in the highest population area likely to be exposed to

high ozone concentrations. Be careful not to locate these monitors in areas where

a local source of nitrogen oxide emissions, such as a highway or a fuel-combustion source, could affect monitor readings.

1 0 CHAPTER 3

Maximum Ozone Regulatory compliance Required as part of the NAMS network. Designed to measure the highest 

exposure ozone concentration in a heavily populated area.

Maximum downwind Ozone Regulatory compliance Required as part of the NAMS network. Designed to measure the 

concentration maximum ozone concentration expected to occur in an urban area. 

Maximum emissions Ozone precursors Control strategy Designed to measure the concentration of nitrogen oxides and VOCs in 

(nitrogen oxides and development proximity to a source. Data are used to model ozone formation. 

VOCs)

Upwind background Ozone and ozone Control strategy Designed to measure the ozone and ozone precursor concentrations 

precursors (nitrogen development entering an urban area from an upwind source. 

oxides and VOCs) 

Type of Site Relevant Pollutants Monitoring Objective Notes
Locating Upwind and Downwind Maximum Concentration Sites. The prevailing

wind direction is a key factor in determining where to locate upwind background

and downwind maximum concentration sites. (See the diagram below illustrating

a sample network design.) You can use models known as wind rose diagrams to

help make these siting determinations. A program to construct wind roses is available from the Support Center for Regulatory Air Models (SCRAM) within EPA’s

Technology Transfer Network (TTN) at http://www.epa.gov/ttn/scram. In

areas dominated by stagnant wind conditions (where winds average less than 1.5

meters/second), it may be difficult to determine the prevailing wind direction. In

stagnant wind areas, upwind and downwind maximum concentration sites should

be located not farther than 10 miles beyond the outermost portion of the urban

fringe.

Wind rose plots alone, however, cannot determine the exact location of maximum

ozone concentration downwind of an emission source. Saturation monitoring

techniques are often used for this purpose. More information about these techniques can be found in EPA’s Photochemical Assessment Monitoring Stations

Implementation Manual at http://www.epa.gov/ttnamti1/pams.html.

OZONE MONITORING 1 1

Example Area Network

Design

(From 40 CFR Part 58, Appendix D)

Legend:

1. A circle denotes a PAMS Site. The

number inside describes the Site

number.

U1. High ozone day predominant

morning wind direction.

U2. Second most predominant high

ozone day morning wind direction

U3. High ozone day predominant afternoon wind direction.
Once you have identified the locations for your monitoring sites, you are ready to

determine how and where to place your monitors at each site. You will need to

consider the following factors when you install your monitors:

! Height. The monitor’s inlet probe should be placed 3 to 15 meters

above ground level. Be sure to locate the probe at least 1 meter vertically and horizontally away from any supporting structure.

1 2 CHAPTER 3

SPECIAL PURPOSE MONITORS

Obtaining Additional Data for Ozone Mapping and Outreach

To gather data on ambient ozone concentrations, the Clean Air Act requires states to establish an ozone

monitoring network consisting of SLAMS and NAMS monitoring stations (and, where needed, PAMS

stations).

In some cases, you may want to gather additional ozone data. When regular data gathering needs to be

supplemented, Special Purpose Monitors (SPMs) are used. For example, some state and local agencies use

SPMs to obtain additional information on where to locate permanent monitoring stations. SPMs are also

used to focus air quality monitoring on a particular area of interest (often for studies intended to help learn

more about a particular aspect of air pollution). 

In addition, state and local agencies may install SPMs to supplement the data they use to map groundlevel ozone concentrations in their area. These additional data are needed in some cases to ensure that

the maps provided to the public are current and accurate.

Some state and local agencies that have considered installing SPMs have been concerned that these additional monitoring stations will generate data demonstrating that their region is a non-attainment area.

Based on this concern, they may elect not to use SPMs. While EPA must consider all relevant, qualitychecked data in reviewing compliance with NAAQS, the Agency recognizes that SPM data can play an

important role in ozone monitoring and mapping. EPA does not expect to use data from ozone monitors

that operate for no more than two years in judging compliance with the ozone map. Becasue SPMs can

remain in one location for only a limited amount of time, their primary purpose is to determine how permanent monitors can be used to fill data gaps and where to locate permanent monitors to provide the best

coverage for the ozone map and populated areas.

Surrogate or “dummy” monitors can also be used to facilitate ozone mapping in areas where information

about local air quality is known but a permanent monitor does not exist. Communities should consult with

the state and EPA air quality contacts to investigate this approach.

Here is how one agency has successfully used SPMs: The Indianapolis Environment Resources

Management Division (ERMD), which handles air monitoring for Indianapolis and Marion County, Indiana,

encountered difficulties in reducing ground-level ozone in the Indianapolis metropolitan area and in downwind areas to safer levels over the years. ERMD officials concluded that they needed to know if additional

ozone was coming into their area from upwind sources.

To gather this information, the officials decided to use SPMs. They installed several stations in various

upwind locations and began taking readings. When the results showed elevated ozone levels in these areas

as well, ERMD was able to begin revising its ozone-reduction strategy. The agency is now working with

organizations in the upwind areas on a regional approach to public education and regulatory enforcement

designed to help both Indianapolis/Marion County and surrounding counties and states deal effectively

with ground-level ozone. 
OZONE MONITORING 1 3

! Airflow. Obstructions such as buildings, trees, and nearby surfaces affect

the flow of ozone and the mixing of pollutants. (Ozone may be

destroyed on contact with these and other surfaces.) Airflow to the inlet

probe must be unrestricted in a horizontal arc at least 270 degrees

around the probe. The probe must be located so that the distance from

the probe to any obstruction is twice the height that the obstruction

protrudes above the probe. If the probe is located on the side of a

building, a 180-degree clearance is required. 

! Separation from roadways. Because automobiles emit nitrogen oxides

that affect ozone concentrations, you must place ozone monitors a

minimum distance from roadways (10 meters to 250 meters, depending upon the average daily traffic flow). See Table 1 in Appendix E of

40 CFR Part 58 for specific separation distances between ozone monitors and roadways, based on daily traffic flow.

! Separation from trees. Because trees and other vegetation can affect

ozone levels, monitor probes should be placed at least 20 meters from

the “drip line” of trees. (The “drip line” is the area where water dripping from a tree might fall.)

For detailed guidance on ozone monitor siting considerations, you can consult

the following references:

! Guideline on Ozone Monitoring Site Selection (available online at

http://www.epa.gov/ttn/amtic/cpreldoc.html).

! “Meteorological Considerations in Siting Photochemical Pollutant

Monitors.” Chu, S. H. (1995). Atmos. Environ. 29, 2905-2913. 

3.3 SELECTING MONITORING EQUIPMENT

The next step in developing your ozone monitoring network is to identify the

equipment you need, ranging from extraction equipment and analyzers to data

recording and transfer systems.

Analyzing Equipment

An ozone analyzer is a self-contained instrument designed to measure the concentration of ozone in a sample of ambient air. You will need to select analyzing

equipment according to the technical needs of your monitoring program and

your available resources. 

Analyzers must also meet the reference method or equivalent method specified by

EPA in Appendix D of 40 CFR Part 50. EPA requires the use of reference or

equivalent methods to help assure that air quality measurements are accurate. The

reference method measurement principles for ozone are also specified in

Appendix D of 40 CFR Part 50. However, equivalent methods may have different measurement principles. Therefore, you should refer to the AMTIC Bulletin

Board at http://www.epa.gov/ttn/amtic, where the EPA maintains a current list

of all designated reference and equivalent methods.
Before you obtain an analyzer, you will need to verify that it meets the reference

method or equivalent method requirements. Because manufacturers may have

changed or modified analyzers without changing the model number, the model

number alone does not necessarily indicate that an analyzer is covered under a designation. Also, any modification to a reference or equivalent method made by a

user must be approved by EPA if the status as a reference or equivalent method is

to be maintained.

Extraction Equipment

The probe used to extract a sample of ozone from the atmosphere for analysis

must be made of suitable material. Extensive studies have shown that only Pyrex®

and Teflon® are suitable for use in intake sampling lines for the reactive gases. EPA

also has specified borosilicate glass and FEP Teflon® as the only acceptable probe

materials for delivering test atmospheres used to determine reference or equivalent

methods. Borosilicate glass, stainless steel, or its equivalent are acceptable probe

materials for VOC monitoring at PAMS. (FEP Teflon® is not suitable as probe

material because of VOC adsorption and desorption reactions.)

Your sampling probe will initially be inert. However, with use, reactive particulate

matter will be deposited on the probe walls. Therefore, the residence time—the

time that it takes for the sample gas to transfer from the inlet of the probe to the

analyzer—is critical. In the presence of nitrogen oxides, ozone will show significant losses even in the most inert probe if the residence time is longer than 20 seconds. EPA requires that sampling probes for reactive gas monitors at SLAMS or

NAMS have a sample residence time of less than 20 seconds. 

Calibration Equipment

Calibration determines the relationship between the observed and the true values

of the ozone concentration being measured. The accuracy and precision of data

derived from air monitoring instruments depend on sound instrument calibration

procedures. (Accuracy is the extent to which measurements represent their corresponding actual values, and precision is a measurement of the variability observed

upon duplicate collection or repeated analysis) Your calibration system must

include an ozone generator, an output port or manifold, a photometer (an instrument that measures the intensity of light), a source of zero air, and whatever other

components are necessary to provide a stable ozone concentration output. Because

ozone is highly reactive and can be destroyed upon contact with surfaces, all components between the ozone generator and the absorption cell must be made of

glass, Teflon,® or other non-reactive material. Lines and interconnections should

be kept as short as possible, and all surfaces must be clean.

1 4 CHAPTER 3
Data Loggers

The analyzers you have set up at your monitoring sites will generate data that

must be recorded and reported. A data logger is a computerized system that can

be used to control and record the data from several instruments. The data logger

unit incorporates software that provides a high level of flexibility for various

applications. With a data logger system, you can interact with the software using

either a keyboard or an interactive, command-oriented interface. Data loggers

perform the following functions:

! Reviewing collected data

! Producing printed reports

! Controlling the analyzer and other instruments

! Setting up instrument operating parameters

! Performing diagnostic checks

! Setting up external events and alarms

! Defining external storage

A modem connection from the monitor to an off-site computer allows data logging (often from more than one monitor) to take place on a single computer. In

addition to the modem, this system requires an off-site computer, data acquisition

and processing software, and a data storage module. Once the data are delivered

to the computer, they are filtered by specified acquisition parameters and stored

in a file in the data acquisition system where further processing and reporting

occurs.

3.4 INSTALLING MONITORING EQUIPMENT

The manufacturer that supplied your monitor should provide you with a complete manual with detailed equipment installation instructions. This section

describes some of the basics of installation monitoring equipment. You will need

to consult the manufacturer’s manual, however, for complete step-by-step installation instructions.

When you install your ozone monitors, you will need to take the following basic

steps:

Inspecting the Equipment

! When the shipment of the monitor is received, verify that the package

contents are complete as ordered.

! Inspect the instrument for external physical damage due to shipping,

such as scratched or dented panel surfaces and broken knobs or 

connectors.

! Remove the instrument cover and all interior foam packing and save

(in case future shipments of the instrumentation are needed). Make

note of how the foam packing was installed.

OZONE MONITORING 1 5
! Inspect the interior of the instrument for damage, such as broken components or loose circuit boards. Make sure that all of the circuit boards

are completely secured. (Loose boards could short out the motherboard.) If no damage is evident, the monitor is ready for installation

and operation. If any damage due to shipping is observed, contact the

manufacturer for instructions on how to proceed.

! If you discover that the instrument was damaged during shipping and it

becomes necessary to return it to the manufacturer, repack it in the

same way it was delivered.

Installing Monitors

Installing an ozone monitor consists of connecting the sample tubing to the sample gas inlet fitting and connecting the primary power and the recorder.

! The sample inlet line connection should be made with 1/4-inch outer

diameter Teflon® tubing.

! The entrance of the sampling system should have provision for a water

drop-out or other means of ensuring that rain cannot enter the system.

Place this water drop-out as far as possible from any sources that could

contaminate the sample.

! Because the analyzer is an optical instrument, it is possible that particulate in the gas sample could interfere with the ozone readings, although

the sampling/referencing cyclic operation of the instrument is designed

to eliminate such interference. In order to avoid frequent cleaning of

the optics and flow handling components, installation of a Teflon® filter

is recommended. A 0.5-micron Teflon® filter will not degrade the ozone

concentration. However, if particulate matter builds up on the filter, the

particulate matter will destroy some of the ozone in the sample. Be sure

to change the filters regularly.

! Since the instrument’s exhaust consists of ambient air with some ozone

removed, ensure that the exhaust cannot re-enter the sample system.

! Install the monitor’s electrical connections as indicated in the manual.

The typical monitoring instrument is designed to operate on standard,

single phase AC electrical power, 50-60 Hz, and 105-125 or 220-240

volts. Most instruments are supplied with a three-conductor power

cable. If you are operating the instrument on a two-wire receptacle, a

three-prong adapter plug should be used with the pigtail wire connected

to the power outlet box or to a nearby electrical ground. (Operating the

instrument without a proper third wire ground may be dangerous.)

Additional Equipment

The recording device, data acquisition equipment, and any monitoring equipment, calibration equipment, or other ancillary equipment should be installed

according to the information supplied in the appropriate manuals.

1 6 CHAPTER 3
Standard Operating Procedures

After you install your monitor, you should develop written Standard Operating

Procedures that describe the operation of each portion of the monitoring site.

Data collected using fully documented procedures have much higher credibility.

Be sure to develop written Standard Operating Procedures whenever the procedure in question is repetitive or routine and will significantly affect data quality.

Guidance for the Preparation of Standard Operating Procedures for Quality-Related

Documents provides information about developing, documenting, and improving

Standard Operating Procedures. It can be found on the Web at

http://es.epa.gov/ncerqa/qa/qa_docs.html#g-.

Environmental Control for Monitoring Equipment

When you install your ozone monitor, you will need to control any possible physical influences that might affect sample stability, chemical reactions within the

sampler, or the function of sampler components. These environmental controls

will help ensure that you receive accurate data from your monitoring network.

The table below summarizes these physical variables and the ways in which you

can control them.

Securing Your Monitoring Site

Your monitoring equipment will need to operate unattended for prolonged periods. Standard security measures such as enclosures, fences, and lighting will help

safeguard the equipment and prevent interference with its operation. To enclose

the monitoring equipment, you might construct a shelter or use a trailer with

appropriate power, telephone, and air conditioning systems.

OZONE MONITORING 1 7

Instrument vibration Design instrument housings, benches, etc. according to manufacturer’s specifications. Use shock-absorbing feet for the monitor and a 

foam pad under analyzer. Attempt to find and isolate the source of the vibration. The pumps themselves can be fitted with foam or 

rubber feet to reduce vibration. If the pumps are downstream of the instruments, connect the pumps by way of tubing that will 

prevent the transfer of vibrations back to the instruments and/or the instrument rack.

Light Shield instrumentation from natural or artificial light.

Electrical voltage Ensure constant voltage to transformers or regulators. Separate power lines. Isolate high current drain equipment such as hi-vols, 

heating baths, and pumps from regulated circuits. The total amps to be drawn should be checked before another instrument is added.

Temperature Regulate air conditioning system. Use 24-hour temperature recorder. Use electrical heating/cooling only.

Humidity Regulate air conditioning system; use 24-hour recorder.

Variable Method of Control
3.5 CALIBRATING MONITORING EQUIPMENT

To ensure the accuracy and precision of data derived from your air monitoring

instruments, you will need to develop reliable instrument calibration procedures.

This section describes two alternative calibration methods: primary calibration

procedures and calibration using a transfer standard.

Primary Calibration Procedures

Dynamic calibration involves introducing gas samples of known concentrations

into an instrument to adjust the instrument to a predetermined sensitivity and

produce a calibration relationship. This calibration relationship is derived from

the instrument’s response to successive samples of different, known concentrations.

The photometer that you use for calibration must be dedicated exclusively to calibration and not used for ambient monitoring. Ozone analyzers are typically

located at widely separated field sites. While a photometer and the photometric

calibration procedure can be used at each field site to calibrate each analyzer, you

may find it advantageous to locate a single photometer at a central laboratory

where it can remain stationary, protected from the physical shocks of transportation, and available to be operated by an experienced analyst under optimum conditions. This single photometer can then serve as a common standard for all analyzers in a network. This central photometer would then be used to certify one or

more ozone transfer standards that are carried to the field sites to calibrate the

ozone monitors. For more information about ozone transfer standards, see

Standards for the Calibration of Ambient Air Monitoring Analyzers for Ozone, available on the AMTIC Technical Guidance Documents Web site at

http://www.epa.gov/ttn/amtic/cpreldoc.html.

1 8 CHAPTER 3

Monitoring Site Checklist

Here’s a list of things to check before operating your ozone monitoring site:

! Have the sampling manifold (if used) and inlet probe for the analyzer

been checked for cleanliness?

! Has the shelter been inspected for weather leaks, safety, and security?

! Has the equipment been checked for missing parts or frayed electrical

cords?

! Are the monitor exhausts positioned so that exhaust will not be drawn

back into the inlet?

! Are field notebooks and checklists available at the site in a secure 

location?

! Have photographs or videotapes of the site been taken after set-up, for

use in reviewing the layout of the monitoring site to ensure that conditions have not changed?
You should conduct a visual inspection of the photometer system prior to use to

verify that the system is in order, all connections are sound, gas flow is not restricted, and there are no leaks. Next, you should perform a linearity test of the photometer according to the manufacturer’s instructions. Accuracy of the photometric calibration system can be verified by occasional comparison with ozone standards from other independent organizations, either directly or using transfer standards. Some portion of the ozone may be lost upon contact with the photometer

cell walls and gas handling components. The magnitude of this loss must be

determined and used to correct the calculated ozone concentration. This loss

must not exceed 5 percent.

To calibrate ozone analyzers, take the following steps:

! Allow the photometer to warm up and stabilize.

! Verify that the flow rates through the photometer cell and into the output manifold are accurate.

! Open the two-way valve to allow measurement of zero air through the

manifold.

! Adjust the ozone generator to produce the required amount of ozone.

! Actuate the two-way valve to allow the photometer to sample zero air

until the cell is thoroughly flushed and record the stable measured

value.

! Actuate the two-way valve to allow the photometer to sample the ozone

concentration until the cell is thoroughly flushed and record the stable

measured value.

! Record the temperature and pressure of the sample in the photometer

cell.

! Calculate the ozone concentration.

! Obtain additional ozone concentration standards by repeating the steps

above with different concentrations of ozone from the generator.

To learn more about calibration procedures, you can review Technical Assistance

Document for the Calibration of Ambient Ozone Monitors (available at

http://www.epa.gov/ttn/amtic/cpreldoc.html).

Calibration Transfer Standards

When the monitor to be calibrated is located at a remote monitoring site, it is

often convenient to use a transfer standard rather than a primary standard calibration system. A transfer standard is defined as a transportable device or apparatus that, together with the associated operational procedures, can accurately

reproduce pollutant concentration standards or produce accurate assays of pollutant concentrations which are quantitatively related to an authoritative master

standard. The primary function of a transfer standard is to duplicate and distribute concentration standards to places where comparability to a primary standard

is required.

OZONE MONITORING 1 9
Because of the nature of ozone, transfer standards must be capable of accurately

reproducing standard concentrations in a flowing system. Ozone transfer standards are complex systems consisting of devices or equipment that generate or

assay ozone concentrations. Ozone concentrations are needed to calibrate an

ozone analyzer for ambient monitoring. Usually a number of such analyzers need

to be calibrated, and they are located at various field sites which may be separated by appreciable distances. Also, these analyzers require recalibration at periodic

intervals. Consequently, a large number of ozone standards will be required at various times and places. Ozone standards may also be needed to check the span or

precision of these analyzers between calibrations.

Follow these procedures to calibrate ozone analyzers using transfer standards:

! Allow sufficient time for the ozone analyzer and the photometer or

transfer standard to warm up and stabilize.

! Allow the analyzer to sample zero air until a stable response is obtained.

Adjust the analyzer zero control to +5 percent of scale.

! Generate an ozone concentration standard of approximately 80 percent

of the desired upper range of the ozone analyzer and allow the analyzer

to sample this ozone concentration standard until a stable response is

obtained.

! Adjust the ozone analyzer span control to obtain a convenient recorder

or data logger response.

! Generate several other ozone concentration standards (at least five others are recommended) over the scale range of the ozone analyzer by

adjusting the ozone source.

! Plot ozone analyzer responses versus the corresponding ozone concentrations and draw the calibration curve or calculate the appropriate

response factor.

To learn more about the use of transfer standards, review the guide Transfer

Standards for Calibration of Ambient Air Monitoring Analyzers for Ozone (available

at http://www.epa.gov/ttn/amtic/cpreldoc.html).

3.6 MAINTAINING YOUR MONITORING EQUIPMENT

AND ENSURING DATA QUALITY

Once you have installed and calibrated your ozone monitoring network, the

process of monitoring ozone in your area can begin. At this point, you should be

sure to develop procedures for checking the quality of your data and maintaining

the monitoring equipment.

2 0 CHAPTER 3
Quality Assurance

To help ensure that your data are valid, you will need to screen it for possible

errors or anomalies. Statistical screening procedures can be applied to ambient air

measurement data to identify data that may not be accurate.

Data validation entails accepting or rejecting monitoring data based on routine

periodic analyzer checks. For example, you will need to check the analyzer span

for excessive drift or changes in recorded data according to the manufacturer’s

specifications. If the span drift is equal to or greater than 25 percent, up to two

weeks of monitoring data may be invalidated. To avoid this situation, you may

want to perform span checks more often than the minimum recommended frequency of two weeks.

You should also monitor the hardcopy output from a data logger to detect signs

of malfunctions, which may include:

! A straight trace (other than the minimum detectable) for several hours

! Excessive noise (noisy outputs may occur when analyzers are exposed to

vibrations)

! A long steady increase or decrease in deflection

! A cyclic trace pattern with a definite time period, indicating a sensitivity to changes in temperature or parameters other than ozone concentration

! A trace below the zero baseline that may indicate a larger than normal

drop in ambient room temperature or power line voltage

! Span drift equal to or greater than 25 percent

Data must be voided for any time interval during which the analyzer has malfunctioned.

In addition, the integrity of air samples may be compromised by faulty delivery

systems such as the sampling interface. For information about quality

control/quality assurance protocols set forth by the EPA, you can refer to

AMTIC’s QA/QC Web site (http://www.epa.gov/ttn/amtic/qaqc.html).

Equipment Maintenance

Each component of your monitoring equipment will have its own maintenance

routine. In many cases, the equipment manual provided by the vendor will offer

detailed maintenance procedures. The table below describes the essential equipment monitoring and maintenance activities you will need to follow. 

OZONE MONITORING 2 1
2 2 CHAPTER 3

Developing a Preventive Maintenance Plan

You should develop a preventive maintenance plan to ensure the equipment monitoring and maintenance procedures are consistently followed. Your preventive

maintenance program should include:

! A short description of each maintenance procedure

! The schedule and frequency for performing each procedure

! A supply of critical spare parts on hand

! A list of maintenance contracts for instruments used in critical measurements

! Documentation showing that maintenance has been performed as

required by the maintenance contract, the Quality Assurance Project

Plan, or test plan

Shelter temperature • Mean temperature between 22° • Check thermograph chart daily • Mark chart for the affected 

and 28°C (72° and 82°F), daily for excessive fluctuations. period of time. 

fluctuations 2°C (4°F). • Repair or adjust temperature 

control system.

Sample introduction system • No moisture, foreign material, • Make weekly visual inspection. • Clean, repair, or replace as 

leaks, or obstructions; sample needed.

line connected to manifold.

Recorder • Adequate ink supply and • Make weekly visual inspections. • Replenish ink and chart paper 

chart paper. supply.

• Legible ink traces. • Adjust recorder time to agree

• Correct settings of chart speed with clock; note on chart.

and range switches.

• Correct time.

Data logger • Complete data storage or • Make weekly visual inspections. • Perform maintenance according 

hardcopy output. to manufacturer’s specifications.

Analyzer operational settings • Flow and regulator indicators • Make weekly visual inspection. • Adjust or repair as needed.

at proper settings.

• Temperature indicators cycling 

or at proper levels.

• Analyzer set in sample mode.

• Zero and span controls locked.

Analyzer operational check • Zero and span within tolerance • Check every two weeks. • Isolate source of error and

limits as specified. repair. 

• After corrective action, 

re-calibrate analyzer.

Precision check • Assess precision by repeated • Check every two weeks. • Calculate and report results of 

measurements. precision check.

Maintenance Issue Acceptance Limits Method of Measurement Corrective Action, If Needed

and Frequency
OZONE MONITORING 2 3

You must perform preventive maintenance periodically to maintain the integrity

of the instrument. You should keep a log book with the instrument, since maintenance is performed according to total hours of “instrument on” time. The following steps are included in preventive maintenance procedures:

! Replace the ozone scrubber cartridge according to the procedures specified by the manufacturer in the operating manual for the analyzer (typically, every 125 hours of instrument operation). The exact life span of

the ozone scrubber is directly proportional to the level and characteristics of the pollutants flowing through it. Most manufacturers recommend that you replace the ozone scrubber cartridge at regular intervals

until you can determine an “average” life span based on your experience

with actual operating conditions at each installation site.

! Clean the cooling fan filter to ensure an adequate air supply through

the cooling fan at the back panel.

The table below lists checks that should be performed as corrective maintenance.

(Procedures for performing the checks, acceptable values, and procedures for performing adjustments are included in the manufacturer’s operating manual.)

To document the performance of these maintenance operations, site personnel

should fill out and maintain data sheets as a permanent record of maintenance

operations. 

The manufacturer’s manual for each piece of instrumentation will provide a list

of recommended spare parts that should be maintained either at the site or at a

central location for easy replacement.

Sample flow check Every 24 hours, or on each day when an operator is 

in attendance

Span check Every 168 hours of instrument operation

Recorder span check Every 168 hours of instrument operation

Zero check Every 168 hours of instrument operation

Control frequency check Every 168 hours of instrument operation

Sample frequency check Every 168 hours of instrument operation

Temperature check Every 720 hours of instrument operation

Pressure check Every 720 hours of instrument operation

System leak check Every 168 hours of instrument operation

Solenoid valve leak check Every 720 hours of instrument operation

Type of Check Recommended Frequency
3.7 ANNUAL NETWORK REVIEW

EPA requires that you conduct an annual network review to determine:

! How well your network is achieving its required air monitoring objectives.

! Whether your network is meeting the needs of the data users.

! How the network might be modified to continue to meet its monitoring objectives and data needs.

Some possible modifications may include terminating existing monitoring stations, relocating stations, or adding new monitoring stations. (For a complete

summary of the network review process, see EPA’s SLAMS/NAMS/PAMS Network

Review Guidance at http://www.epa.gov/ttn/amtic/cpreldoc.html.) 

2 4 CHAPTER 3
4. DATA COLLECTION AND

TRANSFER FOR OZONE

MAPPING

D

uring ozone season, ozone monitors record ozone measurements around the

clock, every day. Before monitoring station data reach you for mapping, the

information is quickly passed through the Automatic Data Transfer System

(ADTS), EPA’s computer system set up for automated data retrieval, management, and distribution. Other data transfer and management systems are commercially available for ozone mapping; however, this handbook focuses on EPA’s

ADTS.

The ADTS enables you to provide data to EPA’s central database, known as the

Data Collection Center, as well as receive data from the Data Collection Center

for mapmaking. If you are a staff member at a state or local agency operating

ozone monitoring stations, you will probably want to obtain ADTS software and

learn about the Internet protocol established for connecting to the system. This

will enable your office to serve as one of the network exchange points for ozone

data. Guidance on obtaining and installing the necessary software and on interacting with the ADTS for data exchange is provided after the overview section of

this chapter. Throughout this chapter, we point you to other sources of help on

the ADTS. 

Readers interested primarily in an overview of the ADTS process may want to

focus on the introductory information in Section 4.1 below. If you are responsible for or interested in implementing ADTS, you should carefully review the

technical information presented in the sections on getting ready, using ADTS for

data collection and transfer, and operations at the Data Collection Center

(Sections 4.2 through 4.4).

4.1 OVERVIEW OF THE AUTOMATED DATA TRANSFER

SYSTEM (ADTS) 

In brief, here’s how the ADTS works: 

Throughout the United States, over 1300 monitoring stations collect ozone concentration data. You can view a map of the U.S. that shows the locations of these

ozone monitors at http://www.epa.gov/airsdata/mapview.htm. These monitors collect ozone around the clock and then report the data as hourly averages.

In general, the monitoring sites are maintained by state or local agencies that collect (or “poll”) the data on a regular basis. Each participating agency collects the

data in its State Host Computer, which is linked to a central database called the

Data Collection Center (DCC). Together, all the State Host Computers and the

DCC make up the ADTS network.

Each State Host Computer is set up to convert collected data to a standard format and then transfer the data to the DCC. At many agencies, the State Host

Computer is configured to transfer data automatically; at some agencies, comDATA COLLECTION AND TRANSFER FOR OZONE MAPPING 2 5
puter equipment limitations require the data transfer to be carried out as a manual operation. 

The DCC is located in North Carolina. It receives ozone monitoring data on a

regular basis from sites around the country. The DCC’s primary tasks are to:

! Manage and quality-check the data.

! Send out the collected data for use in ozone mapping. 

In general, the DCC sends data for mapmaking through individual State Host

Computers, which are set up to download ozone monitoring data from the

DCC—either as a manual or automated process. From the State Host Computer,

ozone monitoring data files make their way to your desktop for your use in developing ozone maps. 

The schematic below shows how the ADTS operates.

Data Flow within the ADTS

The ADTS collects and transfers ozone monitoring data so that the data are readily available for use in mapping and other ozone concentration studies. The

ADTS requires each agency in the network to process and transfer its collected

data according to a schedule that is specific to each state. Thus, when a state

2 6 CHAPTER 4
agency decides when to poll its monitoring stations, it must consult its state

schedule and allow sufficient time to complete the collection, processing, and

transfer of data to the DCC.

Note! 

Polling schedules for various states can be found at

http://ttnwww.rtpnc.epa.gov/ozmap/. You will need a password and

user name to access this site. Please contact Phil Dickerson at dickerson.phil@epa.gov for a password and user name. When you reach

the Ozone Mapping System (OMS) Web page, scroll to the section

titled New! and click on the link called polling schedule table.

The table below shows the approximate times by which collected data moves

through the system. As you can see, real-time ozone data are available to end users

very quickly—usually in 1 to 2 hours.

Here’s a more detailed explanation of how data move through the ADTS system:

! The agency collects data from a monitor at 8:00 a.m. and then every 2

hours between 11:00 a.m. and 9:00 p.m.

! The 8:00 a.m. poll contains all the previous day’s 24-hour observations

(12:00 a.m. to 11:00 p.m.) and all hourly data for today (12:00 a.m.

through 7:00 a.m.). Because this poll contains a complete data set for

yesterday, actual 8-hour averages can be determined by the DCC for

yesterday. This means that animations for the previous day can be created using actual data. (See Chapter 5 on making ozone maps.)

! The 11:00 a.m. poll contains 3 hours of hourly averaged data from

8:00 a.m., 9:00 a.m., and 10:00 a.m. 

! The 1:00 p.m. poll contains 2 hours of averaged data for 11:00 a.m.

and noon. The remaining polls will each also contain 2 hours of data. 

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 2 7

1 Time at which polling of ozone monitors should begin.

2 All times are in EDT. 

3 The standard EPA convention for naming hourly data is to refer to hourly data by its starting time. For example, hourly data averaged from

11:00 a.m. to 11:59 a.m. would be reported as 11:00 a.m. data.

8:00 a.m. 8:40 a.m. 8:45 a.m. 8:50 a.m. 9:20 a.m. 

11:00 a.m. 11:40 a.m. 11:45 a.m. 11:50 a.m. 12:20 p.m.

1:00 p.m. 1:40 p.m. 1:45 p.m. 1:50 p.m. 2:20 p.m.

3:00 p.m. 3:40 p.m. 3:45 p.m. 3:50 p.m. 4:20 p.m.

5:00 p.m. 5:40 p.m. 5:45 p.m. 5:50 p.m. 6:20 p.m.

7:00 p.m. 7:40 p.m. 7:45 p.m. 7:50 p.m. 8:20 p.m.

9:00 p.m. 9:40 p.m. 9:45 p.m. 9:50 p.m. 10:20 p.m.

State Host Computer State Host Computer State Host Computer DCC Processes Data by DCC Transfers Data 

Polls Ozone Monitor 1 2 3 Must Process Data by Must Transfer the Data to End User

to the DCC by
Within 40 minutes of polling data from a monitor, an agency’s State Host

Computer converts and transfers the data to the DCC. For example, an agency

polling data at 1:00 p.m. has until 1:40 p.m. to convert and transfer the data.

Upon receiving the data, the DCC quickly processes the data and transfers it back

within 30 minutes on average. During this time, the DCC merges data, calculates

peak data, performs automatic and manual quality assurance/quality control

(QA/QC) checks, and transfers processed data (today’s hourly and peak ozone

data) to the end user for map generation. 

Note! 

The DCC collects and distributes forecast levels for those agencies and

communities participating in the forecast program. This forecast data

is posted to the EPA AIRNOW Web site (http://www.epa.gov/airnow).

This concludes the overview of the ADTS. If you are interested in technical

details about the ADTS and how to access and use it to exchange ozone monitoring data, please read on. 

4.2 GETTING READY TO USE THE ADTS FOR DATA 

COLLECTION AND TRANSFER

If you wish to set up a State Host Computer to connect to the ADTS, you will

need to install special software that will enable you to use the system to transfer

ozone monitoring station data to and from the DCC. Obtaining and installing

the necessary software and then connecting and setting up operations with the

automated system is relatively easy if you are familiar with the use of software

applications and Internet technology. The guidance and reference information

provided here will help you get started as an ADTS operator. 

Before you obtain and install the software, however, you need to determine

whether you have the necessary computer hardware, software, and connectivity

resources to operate the ADTS. This section will help you make that determination so that you can upgrade your equipment if necessary. Then you will learn

how to obtain and install the necessary software, and finally, how to configure

your system to interact with the ADTS.

Assessing Your Computer Resources

Recognizing that the level of available computer equipment at state agencies

across the country varies considerably, EPA has established three basic hardware,

software, and connectivity options for interacting with the ADTS. Level 1 provides the highest level of performance because it accommodates the greatest level

of automation in transferring data. Level 2, however, allows a level of performance

high enough for most automated operations. Level 3 meets the minimum requirements for interacting with the ADTS; users with Level 3 computer resources are

likely to encounter some limitations in using the system. EPA assumes that most

agencies have computer arrangements that at least meet the requirements of Level

3. Depending on the level of performance you require, you may need to upgrade

your system.

2 8 CHAPTER 4
The attributes of the three performance levels are as follows:

Level 1: Computer systems operating at this level provide the highest degree

of automation for data transfer functions. At this level, the State Host

Computer is set up with a File Transfer Protocol (FTP) server to

allow the DCC to initiate automatic data transfer.

Level 2: Computer systems operating at this level are able to initiate data

transfer to the DCC by FTP, dial-up, or modem (backup). Many

State Host Computers use Windows 95 FTP to upload/download

data to and from the DCC. If you plan to have the DCC call your

State Host Computer automatically, you will need to install FTP

server software.

Also, if your agency plans to initiate data transfer, we strongly recommend that you use a dedicated, hard-wired Internet connection. 

Dial-up connections are unreliable—you may not be able to connect,

the line may be busy, or the modem may not function properly. If

you prefer dial-up, your software might not provide for automatic

connections. If you do not have automatic connection software, we

suggest that you use the Windows Dial-Up Networking software in

combination with the free shareware Dunce (Dial-Up Networking

Connection Enhancement). Both are discussed later in this chapter.

Level 3: Computer systems operating at this level provide performance sufficient for transferring files to the DCC by modem. Modems and 

communications software must support Kermit-Lite file transfers by

modem. (See the description of Kermit-Lite software in the “Other

Software” section below.)

The table below lists the equipment requirements for each performance level:

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 2 9

Level 1 (Preferred) 133 MHz Pentium PC Windows 95 (includes FTP client) Network card or ISDN

16 to 32 MB RAM An FTP server 28.8 K baud modem

100 MB free disk space Direct Internet connection

SVGA or EVGA video Outside firewall or external 

access permitted

Modem (backup)

Level 2 66 MHz 486 PC DOS 6.22 14.4 K baud modem

8 MB RAM Windows 3.1 or Windows for Dial-up Internet connection

Workgroups 

100 MB free disk space PPP/SLIP and FTP clients Modem (backup)

VGA video

Level 3 (Minimum) 16 MHz 386 PC DOS 3.2 or higher 2,400 baud modem

1 MB RAM Modem for Kermit-Lite

20 MB free disk space

Monochrome monitor and card

Level Hardware Software Connectivity
Obtaining and Installing ADTS and Other Software

Once you have determined that your computer system meets ADTS technical

requirements, you can obtain, install, and configure the software and system as

required transfer data. In addition to the ADTS software, you will need other

applications, such as ClockerPro or Clocker, Kermit-Lite for MS-DOS, and data

polling and conversion software. (See “Other Software” on page 32.) Using these

software tools together allows you to poll data from monitoring stations, convert

the data to the appropriate format, and transfer data to and from the DCC.

ADTS Software

The ADTS software allows you to transfer data to and from the DCC. Obtaining,

installing, and configuring the ADTS software is straightforward. See the instructions below. 

Obtaining and Updating ADTS Software

You can obtain the ADTS software (and updates) through the OMS Web site or

by FTP. To download ADTS from the OMS Web site, you need a connection to

the Internet and Internet browser software such as Microsoft Internet Explorer or

Netscape Navigator.

You can find detailed instructions on how to obtain and install the ADTS software in Installation and Operation of the Automatic Data Transfer System for State

Host Computers at http://envpro.ncsc.org/oms/oms-docs.html.

Configuring ADTS Software

Once you have installed the ADTS software, you can configure the files by following the guidance in the ADTS installation instructions file. You will also need

to modify the ADTS configuration to conform with your polling and data conversion software. To do so, follow the instructions provided with your particular

software as well as those in the ADTS installation instructions file. For assistance

in configuring your polling and data conversion software, contact Phil Dickerson

at dickerson.phil@epa.gov.

When you installed the ADTS software, various subdirectories were created under

the c:\oms directory as described in adts-shc.txt. The table on the next page

describes the files from these subdirectories that you will most likely use to configure and operate the ADTS software.

3 0 CHAPTER 4
DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 3 1

To configure files, you can open and edit them with a text editor such as Notepad. 

Appendix A contains tips about how to configure your system for forecast data.

It also explains how to configure files such as oms-env.bat, omscnvrt.inp, and

airs2oms.exe.

Setting Up Your Password

To transfer data from a State Host Computer to the DCC, you will need to establish an FTP account with the DCC with an FTP password. You can obtain a password from Phil Dickerson at dickerson.phil@epa.gov.

After obtaining a password, you can add your password to spw.bat or ws_ftp. It is

strongly recommended you use ws_ftp and not spw.bat to set up your password

because ws_ftp encrypts passwords and makes them very secure. ws_ftp is available

as a free download for U.S. federal, state, or local government employees at

http://www.ipswitch.com/support/versions/index.html. Choose the product

WS_FTP LE and download it. User documentation is available at

http://www.ipswitch.com/support/ws_ftp_le_support.html.

After setting up your password, we recommend that you test your password by

connecting to the DCC via FTP. To connect, the address is

http://stegy.rtpnc.epa.gov, the FTP port is 21, and the USER ID is your threecharacter agency name. (See http://envpro.ncsc.org/oms/pub/SiteInfo/

agency_codes.html.)

\bin omscnvrt.exe Dummy data conversion program. Provides sample source code that shows you how to convert from 

AIRS (Aerometric Information Retrieval System) format to MapGen format.

\config download.pif Windows 95 program to download data from the DCC.

downld31.pif Windows 3.1 program to download data from the DCC.

oms-env.bat ADTS configuration script.

mscustom.ini Kermit-Lite initialization file.

omscnvrt.inp Initialization file for the OMS data conversion program. Used only by agencies without polling software.

shc31.clk Sample Clocker task schedule. 

shc95.clk Sample ClockerPro task schedule.

spw.bat Hidden DCC password file.

upload.pif Windows 95 program to upload data to the DCC. 

upld31.pif Windows 3.1 program to upload data to the DCC. 

\convert omscnvrt.bat Contains most of the customization for your system.

airs2oms.exe Converts AIRS data format to OMS data format.

\data \in Incoming ozone data directory. Contains default directories by year.

\out Outgoing ozone data directory. Contains default directories by year.

\work Work directory for peak forecasts.

\transfer upload.bat ADTS master upload script.

Directory Files Description
Polling and Data Conversion Software

Many agencies use polling software provided by outside vendors to obtain data

from ozone monitoring stations. If your polling software does not include utilities

for converting polled ozone data, the Ozone Mapping Project provides two software tools—omsconvrt and airs2oms—for converting standard AIRS (Aerometric

Information Retrieval System) data files into the OMS standard format. Appendix

A provides detailed information about how to obtain and install omsconvrt and

airs2oms.

Other Software

ClockerPro and Clocker. ClockerPro and Clocker are personal/network program

schedulers for Windows that are designed to schedule programs (or reminders)—

such as the upload and download of data from the DCC—to run at specified

times.

Kermit-Lite. You will need to install Kermit-Lite for MS-DOS, the communications software used by the ADTS as a backup method of file transfer. Kermit-Lite

ensures that your data will be transferred if your other transfer protocol method

(e.g., modem, Internet, or dial-up) should fail.

Connectivity Software. If your agency uses a dial-up network connection to initiate data transfer with the DCC, you may want to use Dunce 2.52 (Dial-Up

Networking Connection Enhancement). Dunce allows for much easier dial-up

networking than Win95 currently provides. Serv-U is a full-featured FTP server

for Windows. If your agency wishes to have your State Host Computer data polled

by the DCC, you can use Serve-U as your FTP server software.

Appendix B contains instructions for obtaining and installing ClockerPro,

Clocker, Kermit-Lite, and Dunce 2.52.

4.3 USING THE ADTS FOR DATA COLLECTION AND

TRANSFER

Now that you have installed and configured the software needed to connect with

the ADTS, you are ready to learn how to use the ADTS system. Operating the

ADTS is relatively easy if you are familiar with the use of software applications and

Internet technology. If you have the appropriate computer resources (as described

in Section 4.2), you can automate much of your system’s interaction with the

ADTS.

This section describes a four-step process for collecting and transferring ozone

monitoring station data to and from the DCC. This section also provides information on maintaining and troubleshooting the system. 

Collecting and Transferring Data

Using the ADTS to collect and transfer data involves the four steps shown below.

The first time you perform these steps, you will need to be attentive to a variety

of details involved in setting up the protocol for your State Host Computer. Once

3 2 CHAPTER 4
you have established the appropriate protocol, however, implementing these steps

should be quick and easy. 

Step 1: Polling Data from Ozone Monitors

During ozone season, ozone monitoring stations typically operate around the

clock and report hourly averaged ozone concentrations. If you are an operator of

a State Host Computer, you should work in conjunction with the DCC to decide

the most appropriate times for polling your monitoring stations for data using the

ADTS. When deciding on polling times, you should consider your schedule for

processing the data and transferring it to the DCC. (See the sample schedule provided in Section 4.1.) When developing your polling and transfer schedule, you

may want to consult with Phil Dickerson at dickerson.phil@epa.gov. 

Once you have established your polling schedule, use the polling software you

installed to access the monitoring station data loggers. Consult the instructions

provided with the software for information about operating your polling software. 

To implement your polling software according to the schedule you developed, we

recommend that you use the ClockerPro or Clocker personal/network program.

If you have the necessary computer resources, these tools will enable your State

Host Computer to automatically poll the data loggers at the specified polling

times.

The polling software allows you to transfer polled data from ozone monitoring

stations to your State Host Computer via a protocol transfer. You acquire the data

by “calling” each monitor’s data logger at specified times throughout the day using

a dedicated hard-wired Internet connection, a dial-up service, or a modem.

Place your polled data in your c:\oms\data\in\{year} directory.

Step 2: Converting the Data

After you poll data from monitoring stations, you must convert it to the correct

format for use in creating ozone maps. This conversion is needed because ozone

monitors record ozone measurements in the AIRS format, while MapGen only

accepts the OMS format. Once you have configured your State Host Computer

to run your conversion software, the data are automatically converted as they are

received from the monitoring stations. 

If you are using software supplied by an outside vendor, you should refer to that

software’s instructions for information on operating data conversion software.

(Your polling software may have come with conversion software.) If you are using

the OMS conversion software, please contact EPA’s Phil Dickerson at 

dickerson.phil@epa.gov for user information.

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 3 3

Polling Data from

Ozone Monitors Converting the Data

Assigning QA/QC

Criteria and

Checking the Data

Transferring Data to

and from the DCC

Tip! 

We strongly recommend that

agencies bordering each

other geographically collect

data from the same monitoring station. If one agency

is unable to collect data, the

other can collect and transfer the data. For example, in

northern Virginia, a few

monitoring stations provide

data to two different agencies. This redundancy allows

one agency to supply the

data when the other cannot. 
Step 3: Assigning QA/QC Criteria and Checking the Data

You can assign specific QA/QC criteria to your data for use by the DCC. You can

also check your data before it goes to the DCC. The OMS Web site contains

example quality assurance values that may be incorporated into the DCC software

(http://envpro.ncsc.org/oms/pub/SiteInfo/03-QC-Table.html.) To assign specific QA/QC criteria, contact Phil Dickerson at dickerson.phil@epa.com. 

You can review and check your data before sending it to the DCC. You can conduct a QA/QC on collected data according to an established written schedule.

(See the sample schedule provided in Section 4.1.)

EPA encourages you to include a check on active and historical ozone monitoring

station files as part of your QA/QC protocol. The active file lists monitoring sites

expected to be operational this summer. The historical file lists ozone monitoring

sites throughout the country that are known to have operated at one time or

another (including currently active sites). It is important to check these files before

data are transferred to the DCC to ensure that no monitoring sites are missing,

coordinates are accurate, and priorities are set correctly. The files can be accessed

at http://envpro.ncsc.org/oms/OMS-docs.html. 

If you make changes to the active or historical file for a monitoring station, 

please document your changes and send the documentation to Ted Smith at 

smith_w@mcnc.org. 

Let’s take a closer look at a station location file so you can see what needs to be

covered when conducting QA/QC. Shown below is part of an active monitoring

station file:

Notice that the file provides the geographic referencing information needed to

plot the ozone data. Any errors in the latitude/longitude coordinates (e.g., 45, 27,

3 4 CHAPTER 4

230210002, 45, 27, 54, 69, 33, 19,’GREENVILLE ‘,ME1-1

230252003, 44, 42, 20, 69, 39, 39,’SKOWHEGAN ‘,ME1-1

230313002, 43, 5, 0, 70, 45, 0,’FRISBEE SCHOOL, KITTERY MAINE ‘,NH1-1,ME1-2

ACCESSING YOUR OZONE DATA

We recommend that you use a dedicated hard-wired Internet connection to

access data from your monitoring stations. Although this type of connection

costs more than dial-up and modem connections, an Internet connection is

more reliable and much more efficient. Dial-up and modem connections

are less reliable because you may be unable to connect, the line may be

busy, or the modem may not work. The following example illustrates the

importance of using a dedicated hard-wired Internet connection: Suppose

a state agency needs to collect data from 40 monitoring stations for the

1:00 p.m. poll and uses the dial-up method. If it takes you approximately

1 minute to connect to each monitor, you will need at least 40 minutes to

collect data from 40 monitors. Thus, using dial-up service may not provide

you with enough time to collect, convert, and transfer all the data files.
54, 69, 33, 19) will cause the data to be plotted in the wrong location when you

generate an ozone map using MapGen.

Note! 

We encourage agencies that border each other geographically to

report data from the same monitoring station. (Note that dual reporting requires that neighboring agencies incorporate one another’s site

and data files in their polling software.) As shown above for AIRS ID

230313002, this redundancy allows NH1-1 to supply the data to the

DCC when ME1-2 is not available. For each station where redundancy occurs, agencies can specify a priority value that the DCC adds to

the station location files. The priority is used to resolve duplicate station data. The higher the value, the higher the priority. If ME1-2 has

primary priority and NH1-1 has secondary priority, the DCC specifies

the codes as “NH1-1, ME1-2.” If ME1-2 fails to submit data for that

site or reports missing data, then data from NH1-1 will be used. 

Step 4: Transferring Data to and from the DCC

Data exchange from the agency’s State Host Computer to the DCC is accomplished in one of two transfer methods: 

! The State Host Computer sends a data file to the DCC (agency initiated).

! DCC obtains the data file from the State Host Computer (DCC initiated).

The diagram below illustrates how data are exchanged via these two transfer

methods.

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 3 5
Because most agencies choose to initiate data transfer from their State Host

Computer to the DCC, the process described below focuses on an agency-initiated exchange. For information on DCC-initiated data transfers, please refer to

http://envpro.ncsc.org/oms/oms-docs.html. To transfer data to the DCC:

1. Provide your agency user ID. Before you can initiate a data transfer, your

agency must establish a user’s account on the DCC. (See the subsection on

configuring the ADTS software in Section 4.2 for information about establishing a user’s account.)

2. Select a data file and send it to the DCC. Sending the data places it on your

user’s incoming data directory on the DCC. For example, if an agency from

Connecticut is identified by the user name CT1, the State Host Computer

will deposit files in the CT1 user directory.

When the State Host Computer successfully transfers a data file to the DCC, the

DCC sends an acknowledgment file to the sending computer for the 8:00 a.m.

poll only. You can check the status of your last transfer (or transfer attempt) by

reviewing the transfer log in c:\oms\transfer\. If you are using Windows FTP,

check the file transfer.log. If you are using WS_FTP, check the file xferlog.txt. 

3. The DCC will obtain the file from the incoming directory. On regular cycles,

the DCC checks the user’s incoming data directory and transfers data files to

its incoming data directory. From here, files are merged, submitted to

QA/QC, stored in a database, archived, and then released to the public.

To upload or download a data file to or from the DCC, follow the instructions

below:

Uploading Data. To upload a data file (e.g., 071414.ct1) from your agency’s State

Host Computer to the DCC, double-click on upload.pif (Windows 95) or

upld31.pif (Windows 3.1) in the c:\oms\config directory. To automatically schedule the upload, you can use ClockerPro or Clocker. Uploading transfers the data

file from the c:\oms\data\in\{year} directory to the DCC user’s incoming data

directory.

Note! 

The ADTS uses the mmddhh.aaa date/time naming convention for the

data file being transferred to the DCC, where mm is the month, dd is

the day, and hh is the hour when the file was created. The aaa is the

three-character code for your agency. For example, if Vermont prepares a file for transmission at 2:25 p.m. (14:25) on June 20, the file

name will be: 062014.vt1. You should base your date/time stamp on

the clock setting on the system doing the transfer, which can be in standard or daylight savings time, provided the DCC is made aware of

which time scale you are using.

Submitting Forecast Data. Your state agency can submit site-specific forecasts as

part of your routine ozone data file. (For more information about ozone forecasting, see the box below.) You need to submit forecast data via the ozone data file

(with the 3:00 p.m. poll) or over the Web using a forecast transmission form. To

submit forecasts using a data file, you will need to configure the ADTS software

as discussed in the section on configuring ADTS. Once configured, the State

Host Computer will insert a forecast packet in the data file being transferred to

3 6 CHAPTER 4
the DCC. Some polling software programs insert a forecast packet into the file,

so users of these software packages will not have to configure the ADTS software

for forecasting. 

If you plan to use the forecast packet, please follow the step-by-step instructions

on the OMS Web site at http://ttnwww.rtpnc.epa.gov/ozmap/. (You will need

a user name and password to access this site. You can obtain a password and user

name from Phil Dickerson at dickerson.phil@epa.gov. Once you reach the

OMS Web site, scroll to the section titled New! and click on the link called 1999

Draft Forecast Plan). Information on The Ozone Forecast Map Plan for the

Northeast States also can be found at http://www.nescaum.org. 

Downloading Data. To download a data file from the DCC, double-click on

download.pif (Windows 95) or downld31.pif (Windows 3.1) in the c:\oms\config

directory. To automatically schedule the download, you can use ClockerPro or

Clocker. Observation data (marked by .obs) and/or gridded data files (marked by

.grd) will be transferred from the DCC’s outgoing data directory to the host computer’s c:\oms\data\in\{year} directory. (Observation data and gridded data are discussed in greater detail in Section 4.4.)

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 3 7

Ozone Forecasting

A number of air quality agencies have used ozone forecasts to warn the

public about unhealthy levels of ozone and to encourage the public to take

voluntary actions to reduce ozone concentrations in their area. For example, in California, the South Coast Air Quality Management District uses

forecasts to predict maximum ozone concentrations for 40 subregions in

the Los Angeles area. 

Ozone forecasts are usually issued by air quality agencies and reported in

local newspapers or on local television or radio stations. Forecasts are an

important part of “ozone action day” programs—public health officials rely

on ozone forecasts when they decide whether or not to call an “action day.”

(See Chapter 6 for more information about ozone action days.)

To help air quality agencies develop and implement forecasting programs,

EPA has developed a guidance document that provides:

! Information on how ozone forecasts are currently used.

! A summary and evaluation of methods currently used to forecast

ozone levels.

! Step-by-step guidance that air quality agencies can follow in

developing and operating an ozone forecasting program.

The guidance document—Guideline for Developing an Ozone Forecasting

Program—is available from EPA’s Technology Transfer Network and can be

downloaded from the Web at http://www.epa.gov/ttncaaa1/.

Tip! 

You should schedule your

download an hour or two

after a routine upload—at

the end of the day, or early

the next day—to ensure

receipt of all available data.

(See the example schedule

provided in Section 4.1.)
Maintaining Your System

As with any application, staff resources are necessary to maintain your agency’s

State Host Computer. This includes providing system support for your software,

hardware, and security needs. Any staff member who is familiar with providing

system support in general and with the ADTS software in particular should be

able to maintain your State Host Computer.

Troubleshooting: Questions and Answers

This section contains information about common troubleshooting issues, presented in question-and-answer format.

Q: Is technical support available for agencies setting up a State Host Computer?

A: Yes. Additional documentation is available at http://envpro.ncsc.org/

oms/oms-docs.html. You also can access a Web Bulletin Board system that

allows you to post and respond to messages from members of the Technical

3 8 CHAPTER 4

Readying Your System for Hourly Data Polling

Indianapolis Environment Resources Management Division

To gather the data needed to map changing levels of ozone during the day,

air quality agencies and offices need to be able to poll data from their monitors frequently—typically, every 1 to 2 hours. These data are then reported

to EPA and made available to the public via Web sites, telephone hotlines,

and other outreach mechanisms.

Making the switch. While changing from daily data polling and transfer to the

more frequent polling is not difficult, the experience of agencies that have

upgraded their systems can be helpful. In 1998, the Indianapolis

Environment Resources Management Division (ERMD), a city/county agency

for Indianapolis and Marion County in Indiana, decided to move to frequent polling as part of their ozone public information initiative. 

Upgrading hardware and software. Since ERMD did not need to add new monitors to gather the required data, the biggest change they had to make was

obtaining and installing software capable of conducting the new polling

regimen. To get the new system functioning smoothly, the agency needed to

dedicate staff time to install and troubleshoot the software, contact the vendor for support, and test the system. In addition, ERMD decided to add

another computer server at their office to handle the polling and data transfer functions. 

Lessons learned. Communication is critical, ERMD staff noted. To change the

software, conduct the data transfers, and implement new quality assurance

procedures, they “reached out” to other state and regional air quality agencies that had undergone similar changes. Talking with these offices provided important insights that helped save time and resources. The office also

communicated closely with EPA staff to ensure ERMD was able to move data

to EPA’s Data Collection Center reliably. 
Workgroup at http://ttnwww.rtpnc.epa.gov/ozmap/. You will need a user

name and password to access the Web board, which you can obtain from Phil

Dickerson at dickerson.phil@epa.gov. When you reach the OMS Web page,

scroll to the section titled New! and click on the link Ozone Mapping Technical

Site. Scroll to the bottom of the new page and click on the link Technical

Workgroup Online Conference. Enter your user name and password to enter the

Web Bulletin Board system. If you are a new user of the Web Bulletin Board,

you will need to create an account and password by clicking the New Users button. 

Q: Can I poll data more frequently than scheduled?

A: Yes. You can collect data from the monitors as frequently as you want. You just

need to configure the ADTS for the State Host Computer. Most states collect

data every one or two hours and some collect it every five minutes. However,

the data are processed by the DCC according to its set schedule.

Q: If my agency has to perform manual polling, do we need to come in on evenings

and weekends, or are alternatives available?

A: Please contact Phil Dickerson at dickerson.phil@epa.gov for information.

Q: What should I do if I miss a polling time for transferring data from the ozone monitor to the State Host Computer?

A: You should complete the transfer as soon as possible and then transfer it to the

DCC.

Q: What should I do if I miss a polling time for transferring data from the State Host

Computer to the DCC?

A: If you miss one polling cycle, the missing data can be interpolated at the DCC.

However, if you miss two or more hours of data, the data are marked as missing. You should still complete the transfer as soon as possible. You can also

transfer the data in the morning along with the 8:00 a.m. poll, which contains

all the previous day’s observations.

Q: What do I do when I can’t log in or connect to the DCC using the ADTS software

on the State Host Computer?

A: Sometimes users enter an incorrect user ID or password. If you are unable to

log in to the DCC but seem to connect, check the oms-env.bat and spw.bat files

to make sure your user ID and password entries are correct and have no leading or trailing spaces in the entries.

If you cannot determine the cause of the failure, set check=y in the oms-env.bat

file and run the system in check mode. This will allow you to test the system

and ensure that it is working properly. You will be able to review your data

prior to release, and the system will pause if it finds errors at the end of the

script. 

If you have a direct Internet connection and are having trouble connecting to

the DCC, check with your network administrator to be sure the problem is

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 3 9
not related to a firewall at your site. Also, note that the DCC uses a firewall

and you may not be allowed access if your Internet protocol address has

changed (e.g., because you changed Internet Service Providers).

If you have difficulty connecting to your Internet Service Provider in a reasonable amount of time, you may wish to consider using ClockerPro or Clocker

to schedule the connection 5 or 10 minutes before the ADTS is scheduled to

transfer your data to the DCC. If you adopt this approach, remember to

increase the time allowed for your connection to be idle before disconnecting.

In addition, the oms-env.bat file contains a debug feature that you can run. Set

the debug variable to Y. You can also send the file to dickerson.phil@epa.gov

for debugging and analysis.

Q: How do I know when the data file has been successfully transferred?

A: When the State Host Computer successfully transfers a data file to the DCC,

the DCC will send an acknowledgment file to the sending computer for the

first morning poll at 8:00 a.m. Acknowledgment files are not sent for other

polling hours because of the large volume of e-mails that would be generated. 

You can check the OMS transfer directory to check for any possible errors in

transferring the data. If you are using Windows FTP, check the file transfer.log.

If you are using WS_FTP, check the file xferlog.txt. 

When the DCC initiates data transfer, it sends a delivery status file to the State

Host Computer. If the DCC successfully connects to the State Host Computer

and transfers data, it deposits an “okay” file on the host computer (e.g., accede).

In the event that the State Host Computer transfer file is not found, the DCC

deposits a “not found” file (e.g., 082114nf.ct1) on the host computer.

Q: How will I be notified when new ADTS software is released?

A: You will be notified by e-mail. Each participant is automatically put on the email list.

Q: Does the DCC calculate forecast data?

A: No. The agency sending the data is responsible for calculating the forecast data

and submitting it to the DCC.

Q: How can an agency submit forecast data?

A: If you choose to participate in the forecast program, the agency can submit the

forecast data via the ozone data file (with the 3:00 p.m. poll) or via a Webbased forecast submission form. After the data are submitted, the DCC will

post it to the EPA AIRNOW Web site (http://www.epa.gov/airnow) for

access by agencies and communities. 

To submit forecast data via the Web or ozone data file, follow the step-by-step

instructions in the OMS Web site at http://ttnwww.rtpnc.epa.gov/ozmap/.

You will need a password and user name to access this site. You can obtain a

password and user name from Phil Dickerson at dickerson.phil@epa.gov.

When you reach the OMS Web site, scroll to the section titled New! and click

4 0 CHAPTER 4
on the link called 1999 Draft Forecast Plan. The Ozone Forecast Map Plan for

the Northeast States, located at http://www.nescaum.org, contains additional

information.

4.4 OPERATIONS AT THE DATA COLLECTION CENTER

(DCC)

Now that your agency has established its State Host Computer and you are using

the ADTS for data collection and transfer, you might be interested in knowing

more about the DCC. The section provides general information about operations

at the DCC in support of the ADTS. 

The DCC, which is located at the Agency’s computing center, functions as the

only ozone data collection facility covering the United States. (Because operating

a data collection system is quite complex, we strongly recommend that state agencies continue to use EPA’s DCC as the central ozone data collection point.)

Nonetheless, if you are interested in information on establishing and operating

your own data collection system, see documentation at http://envpro.ncsc.org/

oms/oms-docs.html.

This section describes the DCC’s main functions, the types of data generated,

formats used, the effect of the new ozone standards on DCC operations, and

DCC’s QA/QC program. 

The DCC’s Main Functions

The DCC’s primary functions are to:

! Obtain ozone monitoring data from state agencies.

! Provide FTP and Kermit servers for State Host Computer-initiated data

transfers.

! Maintain master station location and polling tables.

! Merge data from state agencies.

! Perform automated and manual QA/QC checks on incoming data.

! Compute daily peaks and 8-hour ozone averages.

! Manage and archive the collective database.

! Provide data for map generation.

! Transfer ozone monitoring station data.

Types of Data Generated by the DCC

State agencies report hourly data to the DCC. The DCC uses this information to

generate different types of data, called data groups. These data groups include:

! Daily peaks based on forecasted 8-hour averages.

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 4 1
! Daily peaks based on actual 1-hour averages.

! 8-hour averages derived from 1-hour averages.

! 8-hour averages calculated from actual 1-hour averages.

For example, the DCC calculates actual 8-hour ozone concentrations once a day

following the 8:00 a.m. polling of data files from State Host Computers. This

allows the DCC to base yesterday’s peak map on actual data. This also enables the

DCC to keep a running record of the season’s 8-hour ozone data.

Presentation of Forecast Data

The DCC places forecasts in an ozone forecast table on EPA’s AIRNOW Web site

at http://www.epa.gov/airnow. The table provides a categorical prediction of

ozone levels for each participating metropolitan area. The forecast for each state

is updated approximately 1 hour after the state agency begins collecting data from

its monitoring sites.

Processed Data

The DCC uses two different types of indeces and data formats to display

processed data. It is important to understand these indexes and formats to understand the data you will map.

Two different indeces are used to map the 8-hour and 1-hour values. The first

index is the Air Quality Index (AQI) that shows 8-hour data in parts per billion.

The second index normalizes these parts-per-billion values according to the AQI

scale (0 to 500). (See Chapter 6 for more information about the AQI.)

The DCC can also create two types of ozone data formats: observation data

(marked by the .obs file extension) and gridded data (marked by the .grd extension). Observation data from a State Host Computer contain various data points.

Each point represents an hourly ozone measurement recorded by a monitoring

station. The State Host Computer transfers these hourly data to the DCC. The

DCC then calculates more data groups, such as 8-hour averages and daily peaks,

from the hourly data. All these data groups are included in one file called the

observation file. MapGen software can be used to display each of these data

groups as maps that show, for example, still-frame and animation maps of hourly

data.

Gridded data have generally undergone one more processing step then observation files. When an observation data group is saved as gridded data, the data

group is projected onto a gridded data set. (Data groups are further explained in

Chapter 5, Section 5.3.)

DCC’s QA/QC of Data

The DCC ensures that the data you receive for mapping have been thoroughly

quality-checked. The DCC uses both automated and manual data quality checks

4 2 CHAPTER 4
before finalizing processed data. Among other things, the automated QA/QC

program: 

! Checks to see if the station locations reported by agencies are on the list

of active monitoring station locations.

! Ensures that the files transferred from the State Host Computers conform to the OMS data format. 

! Performs various data quality checks.

Before releasing data, the DCC staff perform manual QA/QC by creating maps

and visually inspecting them. The DCC checks that the contour colors and ranges

flow in categorical increments and accurately reflect changes in ozone concentrations. The DCC looks for such problems as:

! A questionable color range, such as a large red area with a green area

inside, which may indicate a data discrepancy at the ozone monitor.

(An area with “unhealthy” ozone levels is unlikely to surround an area

with “good” ozone levels.)

! Gray areas on a map that identify missing data.

If anomalies on a map are large and cannot be resolved, or if large amounts of data

are missing from the mapping domain, the data will not be released to the 

public. 

Appendix C provides detailed information on how the DCC performs various

automated data quality checks.

DATA COLLECTION AND TRANSFER FOR OZONE MAPPING 4 3
4 4 CHAPTER 4

Developing a State-of-the-Art Ozone Data Transfer System

New Jersey Department of Environmental Protection

The way your system polls data from ozone monitors, checks the data, and

distributes it plays a key role in the quality and usefulness of the resulting

information. In New Jersey, the state’s Department of Environmental

Protection (DEP) has assembled an advanced system with several key features for collecting and transferring ozone data reliably and efficiently.

Polling data frequently. One of these features is frequent data polling. Like

other states, New Jersey established a system of air quality monitors in the

1970s in response to the original Clean Air Act requirements. While other

states’ monitors typically poll their data at 1-hour intervals, New Jersey

structured its system to poll by the minute. (New Jersey initially implemented this rapid reporting capability so that radiation releases from any of the

state’s nuclear power plants could be immediately detected.) To help transfer data reliably, the state uses both leased phone lines and dedicated

Internet access lines. This helps prevent busy signals, line tie-ups, or other

difficulties in sending and receiving data.

Publicizing the data. This near-constant data polling has allowed New Jersey

DEP officials to track ozone levels closely throughout the day during the

ozone season. This information is then made available to the public via frequent updates of the state’s air quality Web site (located at

http://www.state.nj.us/dep/airmon).

Customizing data management software. To manage the flow of all this information, the state needed specialized software for polling data, generating

reports, and sending the data to the DCC. New Jersey DEP asked its software vendor to customize the company’s regular, off-the-shelf product to

include a user interface and capabilities tailored to New Jersey’s system.

Complementing this unique software is New Jersey’s central computer system, which is based on UNIX, an operating system designed for stability

and reliability. DEP officials report an extremely low amount of downtime.

Performing effective quality control. New Jersey has also developed a comprehensive quality assurance system. Quality reviews are built into the monitoring system, with software checks that highlight, for staff review, any data

that fall outside New Jersey DEP-specified maximum fluctuations. Any information that is prepared for release to the public has similar warning flags

built into the data transfer software. DEP programmers also have developed

sophisticated graphing systems that allow ozone monitoring staff to quickly

review nearly every piece of data coming from the monitors so they can pick

up on problems almost immediately—a task that would otherwise be nearly impossible.

Lessons learned. DEP staff emphasize that air quality agencies should try to

develop automated record keeping practices. In New Jersey, computers

record information on every data transfer activity—from initial polling to the

delivery of final data to the DCC. These files have proved invaluable, allowing DEP staff to identify and quickly correct any data difficulties that may

occur.
5. MAKING OZONE MAPS 

N

ow that your ozone monitoring network is in place and you have collected

the resulting data, you can turn to the next step: preparing ozone maps to

depict all this information. EPA has developed an easy-to-use, powerful

application called MapGen that communities can use to make maps that illustrate

the concentration levels of ozone and other data. MapGen will enable you to:

! Generate still-frame images of ozone concentrations, including yesterday’s peak ozone concentrations, today’s peak ozone concentrations,

and snapshots of today’s hourly data.

! Produce animated maps illustrating the movement of ground-level

ozone over time. 

! Customize your maps based on your data and outreach needs.

This chapter offers a complete primer on MapGen. It contains instructions on

obtaining and installing the software, generating maps, using advanced features,

troubleshooting, and obtaining technical support. 

Readers interested primarily in an overview of MapGen’s capabilities and features

may want to focus on the introductory information in Section 5.1 below. If you

are responsible for actual software installation and map generation, you should

carefully review the technical information presented in the sections on getting

started, generating and managing maps, advanced features, and technical support

(Sections 5.2 through 5.5). 

5.1 UNDERSTANDING MAPGEN’S CAPABILITIES

MapGen draws ozone maps in the following way: First, data from ozone monitors are input into MapGen. Then MapGen estimates ozone concentrations in

areas where there are no actual ozone measurements (i.e., in the areas between

monitors). The process of estimating ozone levels is called interpolation. Once

ozone concentration data have been interpolated, MapGen automatically draws

color contours that represent different levels of ozone in the mapping region.

Each of the colors corresponds to the Air Quality Index (AQI) developed by EPA

for ozone and other major air pollutants. (See Chapter 6 for more information

about the AQI.) Five different color contours may appear on an ozone map. Each

color denotes a different level of health concern for ozone.

The screen on page 46 shows one type of image you can compose using MapGen.

This particular map depicts ozone levels in the northeastern United States on

September 14, 1998.

MAKING OZONE MAPS 4 5
The map shows that ozone levels ranged from good to very unhealthy across the

region. The table below shows the air quality descriptors and associated contour

colors for 8-hour ozone data.

Once you become familiar with MapGen, you will be able to customize your

maps. This will allow you to create different types of maps that can serve as effective public outreach and education tools. (For more information on the role the

maps can play in public outreach on ozone, see Chapter 6.) You can also add additional layers of information—including meteorological, geological, and other pollutant data—to generate more comprehensive maps. 

5.2 GETTING STARTED

MapGen was designed to be easy to obtain and install. The first step is to determine if you have the minimum computer hardware and software needed to run

4 6 CHAPTER 5

Green 0–64 Good

Yellow 65–84 Moderate (upper end)

Orange 85–104 Unhealthy for sensitive groups

Red 105–124 Unhealthy

Purple 125–374 Very unhealthy

Contour Color 8-Hour Ozone Range Air Quality Descriptor

(in parts per billion)

Note! 

The legend created by

MapGen currently displays

two shades of yellow for the

contour associated with

moderate air quality (as

shown in the screen at

right). In future releases of

MapGen, the legend will

be changed to display only

one shade of yellow.
MapGen. Once you are satisfied with your computer arrangement, you will need

to follow a simple procedure to install MapGen (and update it, if needed).

Setting Up Your Computer

The following hardware, software, and Internet connection requirements are

quite basic—most likely, your existing setup already meets these requirements.

You will need:

! An IBM PC-compatible computer with a Pentium processor (133

MHz or greater)

! 16 megabytes of RAM (or greater)

! 100 megabytes of free disk space (more will be needed for large animations)

! A super VGA monitor and video card (24-bit or 32-bit color settings

are recommended. Settings at or below 16-bit are inadequate for many

of the colors used for mapping and for some data conversion programs.)

! Windows 95, Windows 98, or Windows NT 4.0

MapGen will work on older systems. For example, you can run the program on a

90 MHz Pentium computer. As with any software, however, the more processor

power, memory, and free disk space your system has, the better MapGen’s performance will be.

Because you will need to download MapGen from the Ozone Mapping System

(OMS) Web site, you will need a connection to the Internet and Internet browser software such as Microsoft Internet Explorer or Netscape Navigator.

Obtaining and Installing MapGen

MapGen is obtained through the OMS Web site. To obtain and install the software, follow these steps:

1. Go to the OMS Web site at http://envpro.ncsc.org/oms/#mapgen-reg.

2. After registering to download MapGen, go to the “Download MapGen” page.

Print out the installation instructions (the mg980611.txt file) and the readme

file.

3. Download mg980611.exe to a directory on your computer.

4. Follow the installation instructions to install the downloaded file onto a directory on your computer. (We recommend that you accept the default directory, C:\oms\, that the installation software creates.)

5. Once MapGen installation is complete, verify that the program is working by

navigating to the C:\oms\ directory and double-clicking on mapgen.exe.

MAKING OZONE MAPS 4 7
Updating MapGen

EPA periodically updates MapGen. If you previously installed MapGen, you may

wish to replace it with the most current version. (Updated versions are posted on

the OMS Web site.) To update MapGen:

1. Go to the Web site ftp://envpro.ncsc.org/pub/oms/mapgen/.

2. Click on the file readme.upd (installation instructions) for instructions on how

to install the most recent version of MapGen. 

3. Click on the file update.bat. (This is a script that installs the update.) Save this

file to a directory on your computer.

4. Click on the self-extracting zip file containing the update files. This executable

file is named according to its release date. For example, if a new release

occurred on June 11, 1998, the new executable would be named u990915.exe.

Save this file to a directory on your computer. 

5. Go to the appropriate directory and double-click on update.bat. The file will

unzip the installation files into the proper directories.

Once you have successfully installed or updated the MapGen software, you’re

ready to begin developing and customizing ozone maps.

5.3 GENERATING AND MANAGING MAPS

This section presents instructions that will guide you through the process of creating, managing, and reviewing still-frame and animated maps using this simple,

five-step process:

Because ozone monitoring data are typically delivered to you from the Data

Collection Center (or a state agency) in ready-to-use format, you should be able

to input ozone measurements into MapGen and immediately begin producing

color maps.

STEP 1: CREATING STILL-FRAME MAPS

In this step, you will learn how to input ozone data into MapGen, choose the type

of data to map, and display data to create a still-frame image.

Before you create your first maps, you will need to understand the difference

between the two types of data you will receive from the Data Collection Center

(or a state agency): 

! Observation data (usually denoted by the .obs file extension)

! Gridded data (usually denoted by the .grd extension)

4 8 CHAPTER 5

Creating Stillframe Maps

Selecting the

Area to Display

in Your Maps

Creating and

Saving Animated

Maps

Customizing

and Saving Your

Maps

Conducting

QA/QC on Maps
For the purposes of creating maps, the main thing you need to know about these

two types of files is that gridded data have generally undergone one more processing step than observation data. When an observation data group is saved as

gridded data, the data group is projected on and saved to a gridded data set. Once

this has been done, the interpolation parameters and chosen data group cannot

be adjusted.

Let’s start by creating a map using observation data.

Creating Maps Using Observation Data

1. Open MapGen by clicking on the mapgen.exe file in your C:\oms\ directory.

MapGen will open up to a blank screen.

2. Go to the File menu and select Open Observation Data. Navigate to the directory in which the data are stored and select the data file you want to use. Open

the data file.

Note! 

If you received your data directly from the Data Collection Center, the

data file will have an .obs extension (as shown in the screen above). For

communities that receive data from a state or local agency, the data

file may have an .obs extension or an extension unique to that agency

(such as .ME1 for a file from Maine).

3. Go to the Plot menu, where you will view the data groups in the files you

opened. Select the data group you want for your map.

The name of each data group indicates what your ozone map will display. For

example, in the screen shown on the next page, the user has selected a data group

to create a map that shows daily peak ozone levels based on predicted 8-hour

ozone level averages.

MAKING OZONE MAPS 4 9
Here are a few other examples of data groups and what they will show in the maps

you create:

! OZONE OBSERVED SAMPLE AVG_TIME=60 INTERVAL=60

START_REF=0

Displays actual 1-hour averages for each hour in the day in parts per billion

(PPB). In keeping with the 8-hour ozone standard, 1-hour ozone values are

displayed using MapGen’s default 8-hour ranges as shown in the table in

Section 5.1.

! OZONE DERIVED SAMPLE AVG_TIME=480 INTERVAL=60

START_REF= -240

Displays 8-hour averages derived from 1-hour averages in PPB. Ozone values are

displayed using the default 8-hour ranges as shown in the table in Section 5.1.

! OZONE OBSERVED PEAK AVG_TIME=60 INTERVAL=1440

START_REF=0

Displays the daily peak based on actual 1-hour averages in PPB. Ozone values are

displayed using the default 8-hour ranges as shown in the table in Section 5.1.

! AQI OZONE Data Groups

Displays the same type of maps for 1-hour, 8-hour, and daily peak ozone concentrations as described in the above data groups. However, ozone values are standardized to the Air Quality Index (AQI) scale. The AQI is explained in the section below on Adjusting Contours.

The illustration below and the table on the next page identify and explain the six

parts of a data group name. This information will help you interpret the name of

any data group—so you can choose the one you want for your map.

5 0 CHAPTER 5

Characteristic Averaging Time Start Reference

OZONE OBSERVED PEAK AVG_TIME=480 INTERVAL=1440 START_REF=240

Variable Measurement Type Interval
MAKING OZONE MAPS 5 1

To learn more about data groups, refer to the Map Generator System User Guide at

http://envpro.ncsc.org/oms/oms-docs.html.

4. After you have selected a data group, select Draw Plot to create a plot of the

data group. (A “plot” is a still-frame image map.) 

Remember that some data groups contain hourly ozone data. Here is how you

can display still-frame, hourly images using these data groups: After using

Draw Plot to create the first hourly map, use the Next Plot option to advance

to the next hour of input data contained in that data group. Keep using Next

Plot to display subsequent hourly maps until the Next Plot option has turned

to gray in color. (When this occurs, there are no more data in the file.) You can

also select Previous Plot to display the previous hour of input data for the

selected data group. Plot menu options are shown below.

That’s it—you’ve created a map using observation data!

Creating Maps Using Gridded Data

With gridded data, all the choices concerning data groups have already been made—

either by the Data Collection Center or by a MapGen user in a previous session.

When you work with gridded data, all you need to do is open the file and display

the still-frame image.

1. Open MapGen by clicking on the mapgen.exe file in your C:\oms\ directory.

MapGen will open up to a blank screen.

2. Go to the File menu and select Read Gridded Data. Navigate to the directory

in which the gridded data are stored and select a grid file. Open that file and

your gridded data map will be displayed.

Congratulations on creating your first maps with MapGen! In Step 2, we’ll look

at how you can adjust your maps to focus on specific regions.

Variable

Characteristic

Measurement Type

Averaging Time

Interval

Start Reference

The pollutant measured (for example, ozone)

The data are either observed, derived, or predicted

Either sample or peak measurements

The averaging time in minutes for the variable reported. For example: 60 (hourly averages), 480 (8-hour averages), or 1440 (daily averages) 

The interval between values. For example: 60 (hourly) or 1440 (every 24 hours). Daily peaks have intervals of 1440 minutes.

The start time of a value in minutes. This can be designated as 0, -240, etc. A start reference of 0 indicates the starting time from when the

ozone average is calculated. A start reference of -240 indicates that the ozone average is a mid-hour average. The average is calculated in

the middle of the 8-hour period based on the four previous and four subsequent hours. 

PARAMETER EXPLANATION

Tip! 

If you cannot view all the

hourly maps contained in an

hourly data file—and the

Next Plot or Previous Plot

options have turned to gray

in color—make sure the

Time Span menu item under

the Animate menu is set correctly. The Animation Start

Time should be set to the

first step (first hour of input

data) and the Animation End

Time should be set to the

last step (last hour of input

data).
STEP 2: SELECTING THE AREA TO DISPLAY IN YOUR MAP

In this step, you will learn how to manipulate your still-frame image map to display ozone concentrations in a particular geographic area. As described below, this

involves adjusting plot area parameters such as latitude and longitude. You then

fine-tune the map view by adjusting its width and height. 

Adjusting the Plot Area Displayed in the Map

1. Go to the Customize menu and choose Select Plot Area and Projection Params to

open the Select Plot Area window displaying a view of you map. (See the screen

below.) Notice that the current parameters for the map view are displayed in

the bottom portion of the window.

2. Select the plot area you want by adjusting the map parameters. (See the screen

on page 53.) The easiest way to do this is to left-click your mouse and then use

the cursor to draw a box around the area you want to focus on. When you have

selected the area you want, release the mouse button. MapGen will automatically recalculate the plot and parameter values shown at the bottom of the

screen.

Alternatively, if you know the coordinates of the area you want to focus on, you

can adjust your map by typing over the values in the Latitude and Longitude

fields at the bottom of the screen. The view of your map shown will move one

way or another, depending on the coordinate values you alter, as described below: 

• Bottom-Left Corner Coordinates: Increase or decrease the latitude

value to expand or contract the map southward. Increase or decrease

the longitude value to expand or contract the map westward.

• Top-Right Corner Coordinates: Increase or decrease the latitude value

to expand or contract the map northward. Increase or decrease the

longitude value to expand or contract the map eastward.

5 2 CHAPTER 5

Tip! 

To display a view of the

entire United States, click

the Full U.S. radio button

and the plot area will be

regenerated. If the northeast corner of the United

States is cut off in the

regenerated map, change

the Top-Right Corner

Longitude value to -58 to

fix this problem.
• Center Coordinates: MapGen automatically recalculates this when

you change a corner coordinate. However, you can adjust the center

coordinates to recenter the plot on the new coordinate(s) position.

• Reference Coordinates: MapGen automatically recalculates this when

you change a corner coordinate. However, you can change the reference coordinates to recenter the map view at the center of the grid

and reduce distortion. 

If you are unfamiliar with reference coordinates and projections, we suggest that

you let MapGen recalculate them automatically.

Regenerating the Map

1. Once you are satisfied with the plot area displayed, click on the OK button.

Then, when prompted, click on the OK button in the Confirm Clear Plot popup window. (Alternatively, you can click on the Cancel button to continue

adjusting the plot area displayed.) Selecting OK will return you to a blank

screen.

2. At the blank screen, regenerate the map by clicking on the Plot menu and

choosing Draw Plot.

Fine-Tuning the View of Your Map

1. Go to the Customize menu and choose Set Plot Size.

2. At the Set Plot Size window (shown at right), type over the

current values in the Width field and the Height field to

adjust the dimensions of the map.

MAKING OZONE MAPS 5 3
You’ve succeeded in showing a specific geographic area on your map! In Step 3,

we’ll work on customizing and saving your map.

STEP 3: CUSTOMIZING AND SAVING YOUR MAP

Now that you have generated an ozone map displaying a plot area of interest, you

can customize your map in a variety of ways.

This section describes several customization features, shown in the screen below.

These include interpolation, which allows you to change the default values programmed into MapGen for interpolating ozone levels between ozone monitoring

stations, and contouring, which allows you to change the default values programmed into MapGen for the color, number, and ranges of different ozone contours.

This section also shows you how to customize your map to show supporting

information such as geographic features, identifying text, and images. After doing

this, you can save your customization settings for use with other maps, and you

can save your customized still-frame image map in a variety of formats. 

Adjusting Interpolation Parameters

Interpolation is the process of estimating ozone concentrations in areas where

ozone monitors do not exist. Estimated data measurements are derived from

neighboring ozone monitors. Interpolation makes it possible to display ozone

concentrations between ozone monitors. 

We recommend that you use the default interpolation parameters, which have

been thoroughly tested for generating appropriate estimated results. Changing the

default settings has the potential to produce unrealistic results, especially if you are

unfamiliar with the methods for estimating concentrations or with the typical

behavior of ozone in a specific mapping region. 

5 4 CHAPTER 5
However, for some local analyses, you may want to adjust the interpolation

parameters. For example, you may want to adjust the parameters to make the

map’s contours appear “smoother.” We strongly recommend that you read further

about interpolation methods at http://envpro.ncsc.org/oms/oms-docs.html

by following the links to Interpolation Documents and Map Generator System User

Guide. These documents will help you understand how to adjust interpolation

parameters.

Adjusting Contours 

Using predetermined breakpoints, MapGen automatically groups ozone data into

different contour ranges keyed to health effects associated with particular ozone

concentrations. Depending on the type of data group you are mapping, you may

use the AQI 8-hour index (parts-per-billion scale) or the AQI common scale.

8-Hour Air Quality Index (parts-per-billion scale)

In keeping with the new 8-hour ozone standard, MapGen uses 8-hour ozone data,

with parts per billion as the measurement unit, to determine the contour breakpoints. These default breakpoints are shown below. It is strongly recommended that

you do not change these contour ranges. Doing so can result in a misinterpretation of

ozone concentration data. These settings are consistent with the new 8-hour ozone

standard. Nonetheless, if you wish to change the contours, please read the Map

Generator System User Guide for further information. The following table shows

the 8-hour index (parts-per-billion scale):

AQI Common Scale

The AQI common scale standardizes pollutants such as ozone to a uniform scale

(0 to 500) to convey a consistent health message across pollutants. The Data

Collection Center calculates AQI 1-hour and 8-hour ozone data groups that are

scaled to the common index for use in mapping. The table at the top of page 56

shows the AQI ranges for the 8-hour and 1-hour data measurements in parts per

billion standardized to the AQI common scale.

MAKING OZONE MAPS 5 5

Contour Color Health Descriptor Breakpoint Range

(parts per billion) (parts per billion)

Green Good 64 0–64

Yellow Moderate 84 65–84

Orange Unhealthy for sensitive groups 104 85–104

Red Unhealthy 124 105–124

Purple Very unhealthy — 125+
The new 8-hour standard requires agencies to report the 8-hour ozone measurements. Using the new AQI 8-hour breakpoints will almost always result in a more

health-protective index than the index based on 1-hour standard. However, a very

small number of areas may have atypical air quality patterns that result in higher

1-hour averages than 8-hour averages. Only in these atypical areas—where the 1-

hour index is more protective—are agencies required to report 1-hour data. For

values above 125 parts per billion, agencies must report the highest value as determined for either the 8-hour or 1-hour value. 

Customizing Your Map with Supporting Information

You are most likely to customize your ozone map by adding geographic features,

other supporting information, and text or images to highlight particular features

in the map. 

Adding Geographic Features

1. Go to the Customize menu and select Other Map Features to access the Map

Features window (shown below).

5 6 CHAPTER 5

Green 0–50 0–64 –9 Good

Yellow 51–100 65–84 –9 Moderate

Orange 101–150 85–104 125–164 Unhealthy for sensitive groups

Red 151–200 105–124 165–204 Unhealthy

Purple 200+ 125+ 205+ Very unhealthy

Contour Color AQI (Common Scale) Equivalent AQI 8-Hour Equivalent AQI 1-Hour Air Quality Descriptor

Ozone Concentration Ozone Concentration 

Range (parts per billion) Range (parts per billion)
To select a feature for display in your ozone map, click on the Show box next to

the option you want. You can also customize the display of these features as

described below:

State Boundaries, County Boundaries, and Transportation Routes. These selections allow you to add state, county, and transportation lines to your map. You

can set the width of these feature lines (specified in point sizes) by typing over

the default setting. You also can set the color by clicking on the Set Color button. 

Observing Stations. This selection plots ozone monitoring station locations on

the map as triangles. You can scale the size of the icons as appropriate for your

map.

Legend. This selection places a color scale legend on the right side of the map.

The legend is based on either the default or the customized contours.

Time and Date. This selection adds to the map the time and date that data

were collected.

Rivers. This selection plots rivers and other waterways on the map.

Water Bodies. This selection displays water bodies on the map. The Choose

File(s) option allows you to select a file with a specific water body shape. In

some cases, you may want to use a water body on your map as an overlay to

focus the portrayal of ozone concentration information on an adjacent land

area. 

Blank Geography Overlay File(s) and Area with Missing Data Color. As with

adding water bodies, these selections allow you to overlay areas in the larger

frame of your map to focus attention on an adjacent area of interest. The

Choose File(s) option allows you to select an appropriate shape from an overlay

file. The files provide shape overlays for all 50 states, as well as areas of Canada

and Mexico. Area with Missing Data Color allows you to choose a color for the

overlay shape.

2. After selecting the map features you want and customizing their display, click

on the OK button. Then refresh the map display by going to the Plot menu

and selecting Draw Plot.

Adding Images and Text

Go to the Customize menu to add an image or text to your ozone map. For example, you might want to add an image to identify a unique geographic landmark

or text to pinpoint the location of a city.

Import Top Bitmap. This selection allows you to place a custom bitmap image

(.bmp) or graphic interchange format (GIF) onto your map. Some Windows

meta files (usually denoted with a .wmf file extension) also can be imported

and placed on the map.

Add Text Label. This selection accesses a window for entering text captions.

After inputting your caption in the text field, click on the OK button. The

caption will appear in the upper left-hand corner of the map display. From

there, you can then move text to the desired location on the map.

MAKING OZONE MAPS 5 7
Change Font. This selection allows you to change the typeface of the text labels.

Set Text Alignment. This selection allows you to align your text within the caption label block. 

Show Text Tags. This selection allows you to select all text and bitmaps as one

group on the map display. Once selected, you can move or delete them. You

can individually select a caption or bitmap by left-clicking on your mouse, and

then pointing at the desired selection.

Clear Text/Top Bitmap. This selection allows you to remove selected text or

bitmap items from the map.

Saving Custom Settings and Still-Frame Image Maps

Once you have established your custom settings for a map, you can save the settings for use in a subsequent MapGen session. Also, you can save the still-frame

image map you’ve created in any of several formats.

Saving Custom Settings

Go to the File menu and select one of the following:

Save Settings to Disk. This selection saves the current custom settings as an initialization file to a disk. (Such files are usually denoted by the .ini file extension.) 

Load Settings from Disk. This selection allows you to select and display custom

settings from a disk.

Save Current Settings as Defaults. This selection allows you to save the current

user settings to a disk in MapGen’s *.ini file. Subsequent MapGen user sessions

will default to those settings.

Return to Defaults. This selection allows you to reset all your custom settings

to MapGen’s “factory default” settings. With this selection, any customized

settings that you have established will be deleted.

Saving Still-Frame Image Maps

To save a still-frame image as a bitmap file, or gridded data, go to the Plot or

File menu as indicated below and select one of the following:

Save Plot as Bitmap (Plot menu). This selection saves the current still-frame

image map as a pixellated image or bitmap. (Such files are usually denoted

with a .bmp file extension.)

Save Plot as GIF (Plot menu). This selection saves the current plot as a GIF file

(such files are usually denoted with a .gif file extension). The GIF option

works only if your monitor is set to 256-color, 24-bit, or 32-bit and higher

resolution. The GIF format enables you to easily incorporate your images onto

Web pages. 

5 8 CHAPTER 5
Note! 

If you are using Windows NT, your map may not convert to a GIF map.

This is because the Windows NT and MapGen’s ImageMagick convert

programs conflict.

Save Gridded Data (File menu). This selection interpolates the open data file

onto a grid, using the current interpolation parameter values, and then saves

the interpolated data. 

Now that you’ve mastered still-frame image maps, you’re ready for animations!

STEP 4: CREATING AND SAVING ANIMATED MAPS

Another way to add supporting information to your ozone map is by animating

the color ozone contours to portray changes in concentrations over time. For

example, if you have sufficient data, you can use your map to show a “movie” of

changes in ozone concentration over the course of an afternoon. In this step, you

will learn how to create an animation for a particular time frame and then save

the settings. 

Getting Ready

1. Go to the Plot menu and select Draw Plot to display your ozone map.

2. Go to the File menu and select Open Observation Data. Then:

• Navigate to the directory in which the data are stored and select the

data file you want to use. Open the data file.

• Go to the Plot menu, where you will view the data groups in the

files you opened. Select an hourly data group for your animation. 

Note! 

You cannot create animations using data groups that have peak measurements.

3. Go to the Customize menu and choose Select Plot Area and Project Params to

open the Select Plot Area window displaying your map. Select your plot parameters to cover the area that will include your animation, then regenerate and

fine-tune your map (see Step 2: Selecting the Area to Display in Your Map).

4. Go to the Customize menu to customize your display or go to the File menu

to load previously saved custom settings (see Step 3: Customizing and Saving

Your Map).

Establishing the Time Span and Color Changes Portrayed

1. Go to the Animate menu and select Time Span. The window that appears

allows you to choose what time period your animation will cover.

In the screen on page 60, for example, time span parameters are presented for

a single observation file brought into MapGen. Because the Animation Start

Time and the Animation End Time scroll bars are set at the extreme first and

last steps, respectively, the window shows that the earliest ozone concentration

MAKING OZONE MAPS 5 9
measurement recorded for this data group was taken at 12 a.m. on September

13, 1998, and the last was taken at 11 p.m. on September 13, 1998.

Note! 

If you bring in two or more continuous observation files, the Animation

Start Time (e.g., 12 a.m. on September 13, 1998) will be the date and

time in the observation files of the earliest ozone measurement taken.

The Animation End Time (e.g., 11 p.m. on September 14, 1998) will

be the date and time in the observation files of the last ozone measurement taken. If you bring in two observation files that do not have a

continuous time span, the time span window will appear with a range

but there will be a gap in the data displayed.

2. Use the scroll bars in the Time Span window to specify a time period for your

animation of ozone concentrations. When you are done, click on the OK button.

3. From the Animate menu, select Frames/Hour to set the number of frames to be

shown in your animation per hour of ozone data. If you set the number at 1,

your animation will show one image for each hour in the chosen time frame,

running in chronological order. If you set the number at greater than 1,

MapGen will create “in-between” frames by linearly interpolating data, which

will make your animation flow more smoothly. A setting of 3 frames per hour

is recommended for a smooth-running animation.

4. Again from the Animate menu, select Animated GIF Settings to control the

speed of your animation by inserting delays and to specify whether your animation should continue to run by looping through the same data.

Playing, Saving, and Retrieving Your Animation 

Now that you’ve established the settings for your animation, it’s time to show the

“movie.” If you decide the animation effectively portrays important information,

you might want to save it. 

1. From the Animate menu, select Animate to view the animation “on the fly,”

and then make adjustments as necessary.

6 0 CHAPTER 5
2. Once you are satisfied with your animation, you can save the file by going to

the Animate menu and selecting one of the following options:

Create Animation File. This selection creates and saves an animation file (such

files are usually denoted by the .ani extension) to a disk. 

Create Animated GIF File. This selection creates and saves a GIF animation file

(such files are usually denoted by the .gif extension) to a disk. 

Note! 

An animation file can take up large amounts of disk space. Typically,

about 312 Kilobytes (KB) of space must be available per 400x400-

pixel frame of the animation. About 600 KB would be required for a

640x480-pixel frame. GIF animations can require even more disk

space. About 200 KB to 6 Megabytes (MB) will be required for the

animated GIF itself. Also, up to several hundred MB may be required

while the image file is being created. 

See the Map Generator System User Guide at http://envpro.ncsc.org/oms/

oms-docs.html for further information on creating animated GIF files and on

the use of a free animated GIF utility. (The current version of MapGen does

not have the capability to generate MPEG video animations.) 

3. To open and play an animation file saved to a disk, go to the Animate menu

and select Play Animation File.

STEP 5: CONDUCTING QA/QC ON MAPS

It’s always a good idea to review your map for data integrity. Detailed QA/QC

considerations are covered in Section 4.3 of this handbook.

5.4 ADVANCED FEATURES

If you’re interested in the following MapGen advanced features, additional information is available in the Map Generator System User Guide at

http://envpro.ncsc.org/oms/oms-docs.html.

MapGen Scripting Language. You can automate map production using MapGen’s

scripting language. See the User Guide’s section on writing and executing

scripts.

ImageMagick Convert. MapGen uses the ImageMagick “Convert” program to

convert bitmaps files to GIF format and to merge individual frames into animated GIF images. ImageMagick utilities also recognize over 40 image formats. See the User Guide’s section on using and obtaining this software.

5.5 TECHNICAL SUPPORT

If you need additional help creating either still-frame image maps or animations,

please refer first to MapGen’s Help system. The Help menu includes entries such

as Beginner Tips and Map Generator Help. (Selecting Map Generator Help opens

the Map Generator System User Guide in HTML format.)

Technical support is also available via the Web. (See the box on page 62.)

MAKING OZONE MAPS 6 1
Known MapGen Bugs

The current version of MapGen includes several known malfunctions that will be

fixed in future releases of the software. For information about these bugs, see the

Map Generator System User Guide at http://envpro.ncsc.org/oms/omsdocs.html. 

Also, if you discover additional bugs in the software, please report them to the

Web-based tracking system at http://envpro.ncsc.org/products/ticket.html. At

the site, the Project—Subsystem you should select is Ozone Mapping System—

Other. You also can report MapGen bugs by sending an e-mail to oms@ncsc.org

or a fax to 919-248-9245.

6 2 CHAPTER 5

Getting Help from EPA’s WebBoard

The Online Ozone Conferencing and Discussion Resource

Real-time ozone monitoring and mapping systems can be complex, and, from time to time, difficulties may

arise when implementing and operating them. Where can you go to get answers to your questions? EPA’s

WebBoard. 

As ozone mapping has taken off in the past several years, state and local officials involved in ozone projects have faced—and tackled—many of the same issues you may now be confronting. WebBoard allows

you to tap into their experience. Developed by EPA in 1998, the site offers informative question-and-answer

sessions and discussions between anyone involved or interested in ozone monitoring and mapping. Have

a question about merging ozone data from multiple agencies? Need help with MapGen’s animations?

Simply post your question on the WebBoard. You’ll get responses from other EMPACT cities, EPA, state air

quality officials, and others offering ideas or recommendations that can help you fix the problem and move

ahead with your program.

WebBoard is divided into several areas. The feature area is the conference, where you can post questions

on different topics and watch the replies flow back. In addition, the site contains a comprehensive search

feature allowing you to check whether any of your questions have been addressed in previous postings.

There also is a chat room hosting real-time discussions on anything related to ozone mapping. The more

users, the better the information—so if you need to learn more about ozone monitoring or mapping, log

on to WebBoard!

To access the WebBoard, you must log in to http://ttnwww.rtpnc.epa.gov/ozmap/. You will also need a user

name and password, which you can obtain by contacting Phil Dickerson at dickerson.phil@epa.gov. Once

you have accessed the Web page, click on the link called Ozone Mapping System Online Conferencing &

Chat to access the Web Board, where you can post and respond to messages about MapGen.
6. COMMUNICATING INFORMATION ABOUT OZONE

AND THE OZONE MAP

A

s your community develops its ozone monitoring and real-time mapping systems, you will want to think about the best ways to communicate the information these systems will yield. This chapter of the handbook is designed to

help you do so:

! It outlines the steps involved in developing an outreach plan and profiles examples of successful ozone outreach initiatives that have been

implemented in EMPACT cities across the country. 

! It also provides guidelines for communicating information about ozone

and includes examples of information, written in an easily understandable, plain-English style, which you can incorporate into your own

communication and outreach materials. 

6.1 CREATING AN OUTREACH PLAN FOR OZONE

Outreach will be most effective if you plan it carefully, considering such issues as:

Who do you want to reach? What information do you want to disseminate? What

are the most effective mechanisms to reach people? Developing a plan ensures that

you have considered all important elements of an outreach project before you

begin. The plan itself provides a blueprint for action. 

An outreach plan does not have to be lengthy or complicated. You can develop a

plan simply by documenting your answers to each of the questions discussed

below. This will provide you with a solid foundation for launching an outreach

effort. 

Your outreach plan will be most effective if you involve a variety of people in its

development. Where possible, consider involving: 

! A communications specialist or someone who has experience developing and implementing an outreach plan.

! Technical experts in the subject matter (both scientific and policy).

! Someone who represents the target audience, i.e., the people or groups

you want to reach. 

! Key individuals who will be involved in implementing the outreach

plan.

As you develop your outreach plan, consider whether you would like to invite any

organizations to partner with you in planning or implementing the outreach

effort. Potential partners include trade associations, environmental organizations,

community groups, health maintenance organizations (HMOs) and clinics,

schools, day care centers, summer camps, local health departments, and other

local or state agencies. Partners can participate in planning, product development

COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 6 3

6. COMMUNICATING 

INFORMATION ABOUT OZONE

AND THE OZONE MAP
and review, and distribution. Partnerships can be valuable mechanisms for leveraging resources while enhancing the quality, credibility, and success of outreach

efforts. 

Developing an outreach plan is a creative and iterative process involving a number of interrelated steps, as described below. As you move through each of these

steps, you might want to revisit and refine the decisions you made in earlier steps

until you have an integrated, comprehensive, and achievable plan. 

What Are Your Outreach Goals?

Defining your outreach goals is the first step in developing an outreach plan.

Outreach goals should be clear, simple, action-oriented statements about what

you hope to accomplish through outreach. Once you have established your goals,

every other element of the plan should relate to those goals. Here are some sample goal statements that a community might develop for its ozone outreach effort:

! Have all local television stations include the ozone map in their weather

reports during ozone season.

! Secure the participation of at least 50 percent of local businesses in

“ozone action day” initiatives.

! Ensure that all local clinics and HMOs include articles about the health

effects of ozone in their newsletters before and/or during the ozone 

season.

Who Are You Trying To Reach?

Identifying Your Audience(s)

The second step in developing an outreach plan is to clearly identify the target

audience or audiences for your outreach effort. As illustrated in the sample goals

above, outreach goals often define their target audiences. You might want to refine

and add to your goals after you have specifically considered which audiences you

want to reach. 

Target audiences for an ozone outreach program might include, for example, the

public, school children, educators, physicians, business leaders, environmentalists,

journalists, and weather broadcasters. Some audiences, such as educators, journalists, and weather broadcasters, may serve as conduits to help disseminate

information to other audiences you have identified, such as the public. 

Consider whether you should divide the public into two or more audience categories. For example: Will you be providing different information to certain

groups, such as the elderly, or parents? Does a significant portion of the public

you are trying to reach have a different cultural or linguistic background from

other members? If so, it likely will be most effective to consider these groups as

separate audience categories. 

6 4 CHAPTER 6
Profiling Your Audience(s)

Outreach will be most effective if the type, content, and distribution of outreach

products are specifically tailored to the characteristics of target audiences. Once

you have identified your audiences, the next step is to develop a profile of their

situations, interests, and concerns. This profile will help you identify the most

effective ways of reaching the audience. For each target audience, consider: 

! What is their current level of knowledge about ozone? 

! What do you want them to know about ozone? What actions would

you like them to take regarding ozone?

! What information is likely to be of greatest interest to the audience?

What information will they likely want to know once they develop

some awareness of ozone issues?

! How much time are they likely to give to receiving and assimilating the

information?

! How does this group generally receive information? 

! What professional, recreational, and domestic activities does this group

typically engage in that might provide avenues for distributing outreach

products? Are there any organizations or centers that represent or serve

the audience and might be avenues for disseminating your outreach

products?

Profiling an audience essentially involves putting yourself “in your audience’s

shoes.” Ways to do this include consulting with individuals or organizations who

represent or are members of the audience, consulting with colleagues who have

successfully developed other outreach products for the audience, and using your

imagination.

What Do You Want To Communicate?

The next step in planning is to think about what you want to communicate. In

particular at this stage, think about the key points, or “messages,” you want to

communicate. Messages are the “bottom line” information you want your audience to walk away with, even if they forget the details. 

A message is usually phrased as a brief (often one-sentence) statement. For 

example:

! The ozone map provides you with real-time information about ozone

levels in your community.

! You can take steps to protect your family’s health from ozone pollution.

! You can help reduce ozone levels in your community.

COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 6 5
Outreach products often will have multiple related messages. Consider what messages you want to send to each target audience group. You may have different

messages for different audiences. 

What Outreach Products Will You Develop?

The next step in developing an outreach plan is to consider what types of outreach

products will be most effective for reaching each target audience. There are many

different types of outreach products in print, audiovisual, electronic, and event

formats. The table below provides some examples. 

The audience profile information you assembled earlier will be helpful in selecting appropriate products. A communications professional can provide valuable

guidance in choosing the most appropriate products to meet your goals within

your resource and time constraints. Questions to consider when selecting products include:

! How much information does your audience really need to have? How

much does your audience need to know now? The simplest, most effective, most straightforward product generally is most effective.

! Is the product likely to appeal to the target audience? How much time

will it take to interact with the product? Is the audience likely to make

that time?

! How easy and cost-effective will the product be to distribute or, in the

case of an event, organize?

! How many people is this product likely to reach? For an event, how

many people are likely to attend?

! What time frame is needed to develop and distribute the product?

6 6 CHAPTER 6

• Fact sheets • Posters • Web pages • Press conferences • Banners

• Brochures • Public service • E-mail message • Speeches • Bumper stickers

• Question-and-answer announcements • Fairs • Mouse pads

sheets • Cable television • Community days • Buttons

• Newspaper and programs • One-on-one meetings

magazine articles • Exhibits • Public meetings

• Editorials • Videos • Media interviews

• Newsletters • Logos • Briefings

• Stuffers

• Press releases

• Educational curricula

• Coloring books

Print Audiovisual Electronic Events Novelty Items
! How much will it cost to develop the product? Do you have access to

the talent and resources needed for development?

! What other related products are already available? Can you build on

existing products? 

! When will the material be out of date? (You probably will want to

spend fewer resources on products with shorter lifetimes.)

! Would it be effective to have distinct phases of products over time? For

example, a first phase of products designed to raise awareness, followed

at a later date by a second phase of products to encourage changes in

behavior. 

! How newsworthy is the information? Information with inherent news

value may be rapidly and widely disseminated by the media.

How Will Your Products Reach Your Audience?

Effective distribution is essential to the success of an outreach strategy. There are

many avenues for distribution. The table below lists some examples.

You need to consider how each product will be distributed and determine who

will be responsible for distribution. For some products, your organization might

manage distribution. For others, you might rely on intermediaries (such as the

media or physicians) or organizational partners who are willing to participate in

the outreach effort. Consult with an experienced communications professional to

obtain information about the resources and time required for the various distribution options. Some points to consider in selecting distribution channels

include:

! How does the audience typically receive information?

! What distribution mechanisms has your organization used in the past

for this audience? Were these mechanisms effective?

! Can you identify any partner organizations that might be willing to

assist in the distribution?

! Can the media play a role in distribution?

COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 6 7

• Your mailing list • TV

• Partners’ mailing list • Radio

• Phone/Fax • Print media

• E-mail • Hotline that distributes products upon request

• Internet • Meetings, events, or locations 

• Journals or newsletters of partner organizations (e.g., libraries, schools, clinics) where products are 

made available 

EXAMPLES OF DISTRIBUTION AVENUES
! Will the mechanism you are considering really reach the intended audience? For example, the Internet can be an effective distribution mechanism, but certain groups may have limited access to it.

! How many people is the product likely to reach through the distribution mechanism you are considering?

! Are sufficient resources available to fund and implement distribution

via the mechanisms of interest?

What Follow-up Mechanisms Will You Establish?

Successful outreach may generate requests for further information or concern

about issues you have made the audience aware of. Consider whether and how

you will handle this interest. The following questions can help you develop this

part of your strategy:

! What types of reactions or concerns are audience members likely to

have in response to the outreach information?

! Who will handle requests for additional information?

! Do you want to indicate on the outreach product where people can go

for further information (e.g., provide a contact name, number, or

address, or establish a hotline)?

What Is the Schedule for Implementation?

Once you have decided on your goals, audiences, messages, products, and distribution channels, you will need to develop an implementation schedule. For each

product, consider how much time will be needed for development and distribution. Be sure to factor in sufficient time for product review. Wherever possible,

build in time for testing and evaluation by members or representatives of the target audience in focus groups or individual sessions so that you can get feedback

on whether you have effectively targeted your material for your audience. Section

6.3 provides guidelines for effectively presenting information about ozone to the

public. 

6 8 CHAPTER 6
COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 6 9

GETTING THE WORD OUT: NORTH CAROLINA’S AIR AWARENESS PROGRAM

North Carolina Department of Environment and Natural Resources, Division of Air Quality

One of the challenges of an ozone outreach effort is focusing the public’s attention on the problem. In

North Carolina, officials have implemented a comprehensive ozone outreach program—the Air Awareness

Program—that has brought ozone to the public’s attention and encouraged them to begin taking action.

North Carolina created the Air Awareness Program in 1996 to help limit ozone levels in three of the state’s

largest metropolitan areas: Charlotte, Raleigh-Durham-Chapel Hill (the “Triad” area), and WinstonSalem-Greenville. Organizers in the state’s Division of Air Quality (DAQ), which operates the program,

have developed a multi-pronged approached to outreach to raise public awareness about ozone.

Holding Ozone Season Kick-Off Events. Each year, the DAQ begins its summer outreach with a series of ozone

season kickoff events. In 1997, the program launched its outreach efforts in the Triad area with a rally at

Durham Bulls Baseball Park before the start of a Bulls baseball game, complete with handouts for fans and

a pre-game ozone weather report by a local television meteorologist. Also, before the start of each ozone

season, the DAQ runs media-targeted special events to coach meteorologists, journalists, and other media

professionals in how to report on ozone during ozone season.

Reaching Out to Schools. Educating school children is another important component of the Air Awareness program. DAQ staff frequently visit schools in the three target metropolitan areas to discuss ozone-related

issues with students and offer teachers a series of classroom tools—from an “Air Adventures Puppet Show”

to a computer-based “Air Jeopardy” game. Children are also encouraged to spread the word about ozone

by talking with their parents about ozone’s health effects and what families can do to help reduce 

summertime ozone levels. 

Building Coalitions. Another strategy for raising public awareness about ozone is to build coalitions with businesses and other organizations willing to help reduce ground-level ozone. Program organizers seek out

potential coalition members in the three target metropolitan areas, encouraging them to join the program

and reach out to their employees to explain ozone and suggest steps they can take. At the end of each

season, DAQ hosts an ozone awards night honoring those coalition members that developed the most

innovative and effective public education efforts.

Getting Results. How well is the Air Awareness Program working? Surveys conducted in Charlotte before and

after the ozone season in 1998 showed that the program had a measurable impact on public awareness

about air pollution. For example, the percentage of survey respondents in the Charlotte area who said that

air pollution was a problem increased from slightly more than half (56 percent) before the Air Awareness

Program to about two-thirds (67 percent) after program implementation. Likewise, the percentage of people who said they took measures to reduce air pollution in their daily routines increased from 41 percent

to 55 percent.

Lessons Learned. To be successful, DAQ staffers advise, it is important to consider these types of programs as

year-round efforts, not just as projects that are limited to ozone. It takes time, they note, to plan events and

recruit coalition members, and because schools are closed for much of the ozone season, outreach to kids

needs to happen before peak ozone season, during the winter and spring. Even if budgets are tight, DAQ

staff recommend that air quality agencies dedicate a full-time staffer to manage their ozone outreach programs all year long.
6.2 SUCCESSFUL OZONE OUTREACH PROGRAMS

Many innovative ozone outreach efforts have already been implemented in

EMPACT cities around the country. These have included:

! Getting ozone maps on TV.

! Launching intensive campaigns to encourage broadcast and print media

coverage during ozone season about ozone and its health effects.

! Developing Web sites that include ozone maps and other ozone-related

information.

! Working with schools to provide information about ozone in science

and health classes.

! Developing “ozone action day” programs aimed at encouraging people,

businesses, and industries to take voluntary measures to help reduce

ozone on days when ozone levels are high.

! Operating hotlines that provide recorded information about current and

forecasted ozone levels.

7 0 CHAPTER 6

TUNING IN TO OZONE

Sacramento Metropolitan Air Quality Management District 

Getting ozone maps on television is one of the best ways to communicate information about ozone levels

to a large number of people. The Sacramento Metropolitan Air Quality Management District (AQMD) has

developed some winning strategies for getting their ozone maps broadcast on local television weather

reports.

Depicting Ozone Graphically. For several years, television meteorologists covering Sacramento have broadcast

short ozone forecasts for the next day without using any supporting maps. Despite these forecasts, the

AQMD found that people did not always fully understand the health effects of ozone and the need to

reduce it. AQMD planners decided to push for animated maps on weather broadcasts depicting the formation and movement of ground-level ozone. According to AQMD staff, seeing a map on TV showing your

region covered with a blanket of orange or red—signifying high or unhealthy ozone levels—can be a powerful motivator.

Working with Weather Service Providers. Weather Service Providers (WSPs) are companies that supply weather

data, images, and forecasts to TV stations, newspapers, and private industry. Generally, local television stations obtain information and images for their weather reports from WSPs. TV stations trust the products that

WSPs supply. If WSPs pick up the ozone maps, station meteorologists are much more likely to use them.

Before agreeing to use the maps, however, the WSPs need to be convinced that the information is worth

providing, quality-checked, and consistently available. AQMD took on this challenge, focusing on the two

main WSPs serving Sacramento area TV stations. AQMD staff provided the WSPs with fact sheets, developed working relationships with their meteorologists, and presented information on ozone maps at meetings attended by WSP staff. AQMD staff expect that at least one WSP will pick up the maps for the 1999

ozone season.
6.3 GUIDELINES FOR PRESENTING INFORMATION

ABOUT OZONE TO THE PUBLIC

As you begin to implement your outreach plan and develop the products selected in the plan, you will want to make sure that these products present your messages and information as clearly and accurately as possible. 

How Do You Present Technical Information to the Public?

Environmental topics are often technical in nature, and ozone is no exception.

Nevertheless, this information can be conveyed in simple, clear terms to nonspecialists, such as the public. Principles of effective writing for the public include

avoiding jargon, translating technical terms into everyday language the public can

easily understand, using the active voice, keeping sentences short, and using headings and other format devices to provide a very clear, well-organized structure.

You may want to refer to the following Web sites for more ideas about how to

write clearly and effectively for a general audience: 

! The National Partnership for Reinventing Government has developed a

guidance document, Writing User-Friendly Documents, that can be

found on the Web at http://www.plainlanguage.gov/.

! The Web site of the American Bar Association has links to important

online style manuals, dictionaries, and grammar primers

(http://www.abanet.org/lpm/writing/styl.html).

As you develop communication materials for a specific audience, remember to

consider what the audience members are already likely to know, what you want

them to know, and what they are likely to understand. Then tailor your information accordingly. Provide only information that will be valuable and interesting to

the target audience. For example, environmentalists in your community may be

interested in why EPA revised the 1-hour ozone standard to an 8-hour standard.

However, it’s not likely that school children will be engaged by this level of detail.

COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 7 1

Recruiting Individual Stations. In addition to working with WSPs, AQMD also began reaching out to the individual local television stations. AQMD developed high resolution ozone maps, put them on their “Spare

The Air” Web site (www.sparetheair.com), and began encouraging local meteorologists to use them. In the

1998 ozone season, this outreach method proved successful. Local station KCRA went to the Web site,

downloaded the animated maps, modified them slightly to fit the station’s graphic style, and ran them on

their weather broadcasts.

Lessons Learned. AQMD attributes its success in getting the ozone maps on television to the working relationships they developed with WSPs and local station meteorologists. In addition to pushing for broadcast

of the maps, AQMD staff provided them with information on all types of air quality issues, made themselves available whenever television station staff needed anything for their weather-related news reports,

and even tried to anticipate and respond to possible future feature story needs.
When developing outreach products, be sure to consider any special needs of the

target audience. For example, if your community has a substantial number of people who speak little or no English, you will need to prepare communication materials in their native language. 

The rest of this section contains examples of text about ozone, ozone monitoring

and mapping, and the health and environmental effects of ozone. These examples,

presented in a question-and-answer format, are written in a plain-English style

designed to be easily understandable by the public. You can use this text as a

model to stimulate ideas for your own outreach language or you can incorporate

components of this text directly into your products.

The Nature Of Ozone Pollution

! What is ozone?

Ozone is an odorless, colorless gas composed of three atoms of oxygen. 

! Is ozone good or bad for people’s health and the environment? 

Ozone occurs both in the Earth’s upper atmosphere and at ground level. Ozone

can be good or bad, depending on where it is found:

• Good Ozone. Ozone occurs naturally in the Earth’s upper 

atmosphere—10 to 30 miles above the Earth’s surface—where it

forms a protective barrier that shields people from the sun’s harmful

ultraviolet rays. This barrier is sometimes called the “ozone layer.” 

• Bad Ozone. Because of pollution, ozone can also be found in the

Earth’s lower atmosphere, at ground level. Ground-level ozone is a

major ingredient of smog, and it can harm people’s health by 

damaging their lungs. It can also damage crops and many common

man-made materials, such as rubber, plastic, and paint. 

! How is ground-level ozone formed? 

Ground-level ozone is not emitted directly into the air but forms when two

kinds of pollutants—volatile organic compounds and nitrogen oxides—mix in

the air and react chemically in the presence of sunlight. Common sources of

volatile organic compounds (often referred to as VOCs) include motor vehicles, gas stations, chemical plants, and other industrial facilities. Solvents such

as dry-cleaning fluid and chemicals used to clean industrial equipment are also

sources of VOCs. Common sources of nitrogen oxides include motor vehicles,

power plants, and other fuel-burning sources.

! Are there times of the year when ozone pollution is of particular

concern?

Yes. In most parts of the United States, ozone pollution is likely to be a concern during the summer months, when the weather conditions needed to form

ground-level ozone—lots of sun, hot temperatures—normally occur. Ozone

pollution is usually at its worst during summer heat waves when air masses are

stagnant. 

7 2 CHAPTER 6
! Are there times of the day when ozone pollution is a particular

concern?

Yes. Ozone levels vary during the day. They are highest during late afternoon

and decrease rapidly at sunset.

The U.S. EPA’s booklet Ozone: Good Up High, Bad Nearby (found on the Web at

http://www.epa.gov/oar/oaqps/gooduphigh) contains additional information

about both good and bad ozone.

The Health Effects of Ozone

! In what ways can ozone affect people’s health?

Ozone can affect people’s health in many ways:

• Ozone can irritate the respiratory system. When this happens, you

might start coughing, feel an irritation in your throat, and/or experience an uncomfortable sensation in your chest. These symptoms can

last for a few hours after ozone exposure and may even become

painful.

• Ozone can reduce lung function. When scientists refer to “lung 

function,” they mean the volume of air that you draw in when you

take a full breath and the speed at which you are able to blow out the

air. Ozone can make it more difficult for you to breathe as deeply

and vigorously as you normally would.

• Ozone can aggravate asthma. When ozone levels are high, more asthmatics have asthma attacks that require a doctor’s attention or the use

of additional asthma medication.

• Ozone can aggravate chronic lung diseases, such as emphysema and 

bronchitis. 

• Ozone can inflame and temporarily damage the lining of the lung.

Ozone damages the cells that line the air spaces in the lung. Within a

few days, the damaged cells are replaced and the old cells are shed. If

this kind of damage occurs repeatedly, the lung may change permanently in a way that could cause long-term health effects.

! When do I need to be concerned about ozone exposure?

Most people only have to worry about ozone exposure when concentrations

reach high or very high levels. Some groups of people are particularly sensitive

to ozone, and members of these groups are likely to experience health effects

before ozone concentrations reach high levels. However, when ozone levels are

very high, everyone should be concerned about ozone exposure. In general, as

ozone concentrations increase, more and more people experience health effects

and the effects become more serious.

COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 7 3
! Who is sensitive to ozone?

People most sensitive to ozone include children, adults who are active outdoors, people with respiratory disease (such as asthma), and people with

unusual susceptibility to ozone. 

• Children. Active children are the group at highest risk from ozone

exposure. Such children often spend a large part of their summer

vacation outdoors, engaged in vigorous activities either in their

neighborhood or at summer camp. Children are also more likely to

have asthma or other respiratory illnesses. Asthma is the most common chronic disease for children and may be aggravated by ozone

exposure.

• Adults who are active outdoors. Healthy adults who exercise or work

outdoors are considered a “sensitive group” because they have a higher level of exposure to ozone than people who are less active outdoors.

• People with respiratory diseases, such as asthma. There is no evidence

that ozone causes asthma or other chronic respiratory disease, but

these diseases do make the lungs more vulnerable to the effects of

ozone. Thus, individuals with these conditions will generally experience the effects of ozone earlier and at lower levels than less sensitive

individuals.

• People with unusual susceptibility to ozone. Scientists don’t yet know

why, but some healthy people are simply more sensitive to ozone

than others. These individuals may experience more health effects

from ozone exposure than the average person.

! Are the elderly sensitive to ozone? What about people with heart

disease? 

Scientists have found little evidence to suggest that either the elderly or people

with heart disease have heightened sensitivity to ozone. However, like other

adults, elderly people will be at higher risk from ozone exposure if they suffer

from respiratory disease, are active outdoors, or are unusually susceptible to

ozone.

! What can I do to avoid unhealthy exposure to ozone?

You can take a number of steps to protect yourself when ozone concentrations

reach unhealthy levels. The chart on page 75 tells you what types of health

effects may occur when ozone levels are considered good, moderate, unhealthy

for sensitive groups, unhealthy, and very unhealthy. It also tells you what you

can do to avoid these effects. (The example text on the Air Quality Index,

beginning on page 77, contains additional text about communicating information about the health effects of ozone at different concentration levels.)

7 4 CHAPTER 6
COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 7 5

1 Members of sensitive groups include children who are active outdoors; adults involved in moderate or strenuous outdoor activities; individuals with respiratory disease, such as asthma; and individuals with unusual susceptibility to ozone.

Good What are the possible health effects?

• No health effects are expected.

Moderate What are the possible health effects?

• Unusually sensitive individuals may experience respiratory effects from prolonged exposure to ozone during 

outdoor exertion.

What can I do to protect my health?

• When ozone levels are in the “moderate” range, consider limiting prolonged outdoor exertion if you are 

unusually sensitive to ozone.

Unhealthy for Sensitive Groups What are the possible health effects?

• If you are a member of a sensitive group,1 you may experience respiratory sumpoms (such as coughing or 

pain when taking a deep breath) and reduced lung function, which can cause some breathing discomfort.

What can I do to protect my health?

• If you are a member of a sensitive group,1 limit prolonged outdoor exertion. In general, you can protect 

your health by reducing how long or how strenuously you exert yourself outdoors and by planning outdoor 

activities when ozone levels are lower (usually in the early morning or evening). 

• You can check with your State air agency to find out about current or predicted ozone levels in your location. 

This information on ozone levels is available on the Internet at http://www.epa.gov/airnow.

Unhealthy What are the possible health effects?

• If you are a member of a sensitive group,1 you have a higher chance of experiencing respiratory symptoms 

(such as aggravated cough or pain when taking a deep breath), and reduced lung function, which can cause 

some breathing difficulty. 

• At this level, anyone could experience respiratory effects.

What can I do to protect my health?

• If you are a member of a sensitive group,1 avoid prolonged outdoor exertion. Everyone else—especially 

children—should limit prolonged outdoor exertion.

• Plan outdoor activities when ozone levels are lower (usually in the early morning or evening).

• You can check with your State air agency to find out about current or predicted ozone levels in your location. 

This information on ozone levels is available on the Internet at http://www.epa.gov/airnow.

Very Unhealthy What are the possible health effects?

• Members of sensitive groups1 will likely experience increasingly severe respiratory symptoms and impaired 

breathing.

• Many healthy people in the general population engaged in moderate exertion will experience some kind of 

effect. According to EPA estimates, approximately:

- Half will experience moderately reduced lung function.

- One-fifth will experience severely reduced lung function.

- 10 to 15 percent will experience moderate to severe respiratory symptoms (such as aggravated cough and 

pain when taking a deep breath).

• People with asthma or other respiratory conditions will be more severely affected, leading some to increase 

medication usage and seek medical attention at an emergency room or clinic.

What can I do to protect my health?

• If you are a member of a sensitive group,1 avoid outdoor activity altogether. Everyone else—especially 

children—should limit outdoor exertion and avoid heavy exertion altogether.

• Check with your State air agency to find out about current or predicted ozone levels in your location. 

This information on ozone levels is available on the Internet at http://www.epa.gov/airnow.

Ozone Level Health Effects and Protective Actions
In general, your chances of being affected by ozone increase the longer you are

active outdoors and the more strenuous the activity you engage in. Therefore,

it is recommended that you limit outdoor activities as ozone levels rise to

unhealthy levels. You can do this by limiting both the amount of time you are

active outdoors and your activity level. For example, if you’re involved in an

activity that requires heavy exertion, such as running or heavy manual labor,

you can reduce the time you spend on that activity or substitute another activity that requires less exertion. In addition, you can plan outdoor activities

when ozone levels are lower, usually in the early morning or evening.

For additional, easy-to-understand information about the health effects of ozone,

you can read EPA’s booklet Smog: Who Does It Hurt? (found on the Web at

http://www.epa.gov/airnow/health. EPA has also developed a fact sheet about

ozone’s health and environmental effects. It can be found on the Web at

http://ttnwww.rtpnc.epa.gov/naaqsfin/o3health.htm.

Ozone and the Clean Air Act

! Are there federal laws that regulate ground-level ozone?

Yes. Ground-level ozone is regulated under the federal Clean Air Act, which is

the comprehensive federal law that regulates air emissions in the United States.

The Clean Air Act requires the U.S. EPA to set health-based standards for six

commonly occurring air pollutants, including ozone. These standards are

known as the National Ambient Air Quality Standards (NAAQS). The

NAAQS can be defined as the levels of air quality that EPA has determined to

be generally protective of people’s health. The Clean Air Act requires each state

to develop and implement a plan for meeting and maintaining the NAAQS

for ozone and other major pollutants within their state.

You can find out more about the Clean Air Act and the NAAQS in EPA’s Plain

English Guide to the Clean Air Act (http://www.epa.gov/oar/oaqps/

peg_caa/pegcaain.html.)

! What is meant by the new 8-hour standard for ozone?

In 1997, EPA adopted new, more stringent standards for ozone, based on

research that found that the original NAAQS for ozone, known as the 1-hour

standard, was not adequately protective of human health. The 1-hour standard

limited ozone levels to 0.12 parts per million averaged over a 1-hour period.

The new standard, known as the 8-hour standard, requires that a community’s

ozone levels be no higher than 0.08 parts per million when averaged over an

8-hour period.

! How are ground-level ozone levels measured?

Under the Clean Air Act, states are required to establish air monitoring networks—air quality surveillance systems that consist of a series of carefully

placed monitoring stations. Each station measures the concentrations of

important air pollutants, including ground-level ozone, in the immediate

vicinity of the station. States are required to report the data gathered from the

monitoring stations to the EPA.

7 6 CHAPTER 6
The Ozone Map

! What is the ozone map?

The ozone map is a tool designed to provide the public with easy-to-understand information about ozone levels in their community and throughout

their region. The map uses color contours to show concentrations of groundlevel ozone. The colors on the map change as the ozone concentrations change.

The maps can show:

• Yesterday’s actual ozone levels.

• Today’s actual ozone levels.

• Forecasts of tomorrow’s peak ozone levels.

• Animations that depict the formation and movement of ozone

throughout the course of the day.

! What do the map’s colors mean?

The ozone map is color-coded to indicate the level of health concern associated with the ozone concentration. For example, green means ozone levels are

“good,” yellow means they are “moderate,” orange means they are “unhealthy

for sensitive groups,” red means they are “unhealthy,” and purple means they

are “very unhealthy.” Once you understand the color scheme, you can use the

map to quickly determine whether ozone concentrations are reaching

unhealthy levels in your area.

! How is the ozone map created?

The map is created using specially designed computer software. Real-time,

hourly ozone data provided by state and local air monitoring stations are input

into the software, called MapGen. MapGen takes these ozone concentration

data and automatically draws color contours coded to different levels of ozone

concentrations.

! Where can I see the ozone map?

In some areas of the U.S., the ozone map is shown on televised weather broadcasts and in local newspapers. For many areas of the country, the ozone map

is available over the Internet on EPA’s AIRNOW Web site

(http://www.epa.gov/airnow). AIRNOW also contains facts about the

health and environmental effects of air pollution, ideas about ways you can

protect your health and actions you can take to reduce pollution, and links to

state and local air pollution control agency Web sites with real-time air pollution data. 

The Air Quality Index

! What is the Air Quality Index?

The Air Quality Index (AQI) is a tool developed by EPA to provide people

with timely and easy-to-understand information on local air quality and

COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 7 7
whether it poses a health concern. It provides a simple, uniform system that

can be used throughout the country for reporting levels of major pollutants

regulated under the Clean Air Act. In addition to ground-level ozone, these

pollutants include carbon monoxide, sulfur dioxide, particulate matter (soot,

dust, particles), and nitrogen dioxide1

. You may sometimes hear the AQI

referred to as the Pollutant Standards Index.

The AQI converts a measured pollutant concentration to a number on a scale

of 0 to 500. The AQI value of 100 corresponds to the National Ambient Air

Quality Standard established for the pollutant under the Clean Air Act. This is

the level that EPA has determined to be generally protective of human health.

The higher the index value, the greater the health concern.

! What do the Air Quality Index health descriptors mean?

As shown below, the Air Quality Index scale has been divided into six categories, each corresponding to a different level of health concern. Each category is also associated with a color. (The same color scheme is used in the ozone

map.)

The level of health concern associated with each AQI category is summarized

by a descriptor:

Good. When the AQI value for your community is between 0 and 50, air quality is considered satisfactory in your area.

Moderate. When the index value for your community is between 51 and 100,

air quality is acceptable in your area. (However, people who are extremely sensitive to ozone may experience respiratory symptoms.)

Unhealthy for Sensitive Groups. Some people are particularly sensitive to the

harmful effects of certain air pollutants. For example, people with asthma may

be sensitive to sulfur dioxide and ozone, while people with heart disease may

be sensitive to carbon monoxide. Some groups of people may be sensitive to

more than one pollutant. When AQI values are between 101 and 150, members of sensitive groups may experience health effects. Members of the general

public are not likely to be affected when the AQI is in this range.

7 8 CHAPTER 6

1 Lead is also considered a major air pollutant under the Clean Air Act. However, because all areas of

the United States are currently attaining the NAAQS for lead, the AQI does not specifically address

lead.

Green 0 to 50 Good

Yellow 51 to 100 Moderate

Orange 101 to 150 Unhealthy for Sensitive Groups

Red 151 to 200 Unhealthy

Purple 201 to 300 Very Unhealthy

Maroon 301 to 500 Hazardous

Color Air Quality Index Value Health Descriptor
Unhealthy. When AQI values are between 151 and 200, everyone may begin

to experience health effects. Members of sensitive groups may experience more

serious health effects.

Very Unhealthy. AQI values between 201 and 300 trigger a health alert for

everyone.

Hazardous. AQI values over 300 trigger health warnings of emergency conditions. AQI values over 300 rarely occur in the U.S.

! How is the Air Quality Index calculated?

State and local air quality monitoring networks take measurements of levels of

ozone, fine and coarse particulate matter, carbon monoxide, nitrogen dioxide,

and sulfur dioxide several times a day. These raw measurements are then converted into corresponding AQI values using standard conversion scales developed by the EPA. For example, an ozone measurement of 0.08 parts per million, which happens to be National Ambient Air Quality Standard for ozone,

would translate to an AQI value of 100.

Once the AQI values for the individual pollutants have been calculated, they

are then used to calculate an overall single index value for the local area. The

single AQI value is determined simply by taking the highest index value that

was calculated for the individual air pollutants. This value becomes the AQI

value reported in a community on a given day. For example, say that on July

12, your community has an AQI rating of 115 for ozone and 72 for carbon

monoxide. The AQI value that will be reported that day for your community

is 115. On days when the AQI for two or more pollutants is greater than 100,

the pollutant with the highest index level is reported, but information on any

other pollutant above 100 may also be reported. 

! When and how is the Air Quality Index reported to the public?

In metropolitan areas of the U.S. with populations over 350,000, state and

local agencies are required to notify the public on days when the AQI for that

area exceeds 100. They may also report the AQI levels for all pollutants that

exceed 100. Even in areas where reporting is not required, EPA, state, and local

officials may use the AQI as a public information tool to advise the public

about how local air quality might affect their health, and what actions they can

take to protect their health and improve air quality. You may see the AQI

reported in your newspaper or on the Internet, or it may be broadcast on your

local television or radio station. In some areas, AQI information is available on

a recorded telephone message. 

More information about the AQI is contained in EPA’s brochure Measuring

Air Quality. It can be found on the Web at http://www.epa.gov/oar/

oaqps/psi.html.

COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 7 9
Actions to Reduce Ground-Level Ozone

! What can I do to reduce ozone pollution?

You can do a number of things to help prevent the formation of ground-level

ozone. On days when ozone levels are high, you can take the following steps:

• Instead of driving, use mass transit, or walk or ride a bike—if these

activities require moderate levels of exertion. (Keep in mind that

because fitness levels vary widely among individuals, what is moderate exertion for one person may be heavy exertion for another.) 

• Consider eating lunch at your desk rather than driving to a restaurant.

• Share rides. 

• Make sure your car is well-tuned.

• Be careful not to spill gasoline when you fill the tank of your car or

lawnmower.

• Refuel your car or lawnmower after dusk.

• Replace your gas-powered lawn mower with a manual or electricpowered unit.

• Don’t mow the lawn or use an outdoor barbecue.

• Use water-based paints instead of oil-based paints.

8 0 CHAPTER 6
COMMUNICATING INFORMATION ABOUT OZONE AND THE OZONE MAP 8 1

ORGANIZING OZONE ACTION DAYS

Metropolitan Washington Council of Governments & the Baltimore Metropolitan Council

Air quality planners in many EMPACT areas have realized that unless the public begins to cut back voluntarily on activities that contribute to ozone formation—particularly on days when meteorologists predict

high levels—their communities will face tough ozone-reduction measures down the line. But getting individuals to change their behavior can be difficult. Here’s how the Baltimore/Washington, D.C. region tackled this challenge.

Launching Ozone Action Days. The Metropolitan Washington Council of Governments and the Baltimore

Metropolitan Council created the ENDZONE program (Partners to End Ground-Level Ozone) in 1994.

From behavior modification surveys conducted previously, ENDZONE’s organizers knew area residents

were concerned about air quality but didn’t know how they could help. In response, ENDZONE planners

launched their Ozone Action Days program. Ozone action days, which have been initiated in a number of

EMPACT areas, are designed to give individuals information about steps they can take to help reduce

ground-level ozone when especially high ozone levels (called “Code Red” days) are forecast.

Recruiting Partners. ENDZONE’s Ozone Action Days strategy is based on recruiting high-profile industries,

large retailers, and other businesses and organizations to commit to helping reduce ground-level ozone.

There are two major benefits to this approach:

! Each partner educates their employees and customers on ground-level ozone and the concrete

steps they can take when Code Red days are forecast. This approach enables the program to

reach large numbers of individuals.

! The partners also initiate very public ozone reduction actions—often covered by the media—that

in turn may influence many other individuals and organizations to follow suit.

Providing Tools to Partners. After recruiting over 400 local businesses and industries, ENDZONE staff provided the partners with extensive ozone outreach material and ideas. This gave partners the start they need

to develop their own ozone outreach programs. For example, after educating their employees about

ozone, International Paper went into the community to host an ozone workshop and partner with a local

elementary school to teach kids about ozone. Amoco offered a $4 rebate to customers for refueling after

dark on Code Red days. And a local chamber of commerce placed articles in community newspapers all

summer long about the need to change behavior when ozone levels are high.

Lessons Learned. What have organizers learned from this effort? Feedback from the partners has shown that

the public has begun to understand what contributes to ground-level ozone. While people recognized that

driving was an ozone-contributing activity, for example, many were unaware of how much ozone they

could prevent by not operating lawnmowers and other lawn and garden power equipment. Ozone Action

Days staff also learned to pick their behavior modification targets carefully. While boating is an important

contributor to ground-level ozone, for example, efforts to reduce this activity during ozone incidents were

unsuccessful—while people would forgo mowing the lawn on a hot summer’s day, boat owners typically

were not willing to skip boating when the weather turned hot and muggy. In general, program organizers

credit positive initial results on tying individual efforts to ozone incidents: when bad ozone levels are forecast, residents are motivated to take action. Still, organizers recognize that the kinds of changes needed

won’t happen overnight. They caution that it is important to think about what changes will be needed 10

to 15 years from now and to structure an outreach program around long-term goals.

You can find out more about ENDZONE’s Ozone Action Days program at http://www.endzonepartners.org/ and about other state and municipal ozone action days programs at

http://www.epa.gov/airnow/action.html.
8 2 CHAPTER 6
APPENDIX A 

TIPS ON CONFIGURING THE AUTOMATIC DATA 

TRANSFER SYSTEM (ADTS)

This appendix contains tips on:

! Configuring your system for forecast data.

! Configuring files such as oms-env.bat, omscnvrt.inp, and airs2oms.exe. 

Forecast Data

Agencies and communities are strongly encouraged to participate in the EPA forecast program. By participating in this program, communities can receive ozone

forecasts (for today and tomorrow) from the EPA AIRNOW Web site

(http://www.epa.gov/airnow). If you choose to participate, your agency will be

responsible for calculating the forecast data and submitting it via the ozone data

file (with the 3:00 p.m. poll) or a Web-based forecast submission form. After the

data are submitted, the Data Collection Center (DCC) will post it to EPA’s

AIRNOW Web site for access by agencies, communities, and individuals. 

Please follow the step-by-step instructions in the Ozone Mapping System (OMS)

Web site at http://ttnwww.rtpnc.epa.gov/ozmap/ for submitting forecast data

via the Web or ozone data file. (You will need a password and user name, which

you can obtain from Phil Dickerson at dickerson.phil@epa.gov. When you

reach the OMS Web site, scroll to the section titled New! and click on the link

called 1999 Draft Forecast Plan). The Ozone Forecast Map Plan for the Northeast

States, located at http://www.nescaum.org, contains additional information.

OMS-ENV.BAT

This file contains most of the customization for your system. Please see the installation instructions file adts-shc.txt for step-by-step instructions on configuring

oms-env.bat. You will not need to modify oms-env.bat if you are using specific

polling software listed in adts-shc.txt.

When you configure oms-env.bat, you will edit some lines of code. When you edit

the code for SET AGENCY, you will enter your three-character agency ID (e.g.,

MA1). You can find list of agency IDs at http://envpro.ncsc.org/oms/

pub/SiteInfo/agency_codes.html.

If you decide to submit data for your forecast via the ozone data file, you will need

to configure oms-bat.env by editing the code for SET FCST. When you edit the

code for SET FCST, you will determine whether you want forecasts to be calculated based on your ozone data. If SET FCST is set to Y, the Automatic Data

Transfer System (ADTS) will insert a forecast packet in the file being transferred

to the DCC. (Some polling software applications insert a forecast packet into the

file, so the FCST variable should be set to N.) 

TIPS ON CONFIGURING THE AUTOMATIC DATA TRANSFER SYSTEM (ADTS) A 1
OMSCNVRT.INP

This is the initialization file for the data conversion program and should be used

by agencies without polling software. You can download this file from

ftp://envpro.ncsc.org/OMS/Utility/. Please contact Phil Dickerson at dickerson.phil@epa.gov for information on obtaining and configuring this file.

AIRS2OMS.EXE

This file converts Aerometric Information Retrieval System (AIRS) data format to

OMS data format and should be used by agencies without polling software. To

obtain this program, download the convert.exe file from ftp://envpro.ncsc.org/

OMS/Utility/. Save the file in the c:\oms\convert directory, double click on convert.exe to extract the airs2oms files, and then follow the installation instructions

in airs2oms.doc. (The converter file is also distributed with MapGen, discussed in

Chapter 5 of this handbook, and it will be placed in the c:\oms\convert directory

when you install MapGen.)

A 2 APPENDIX A
APPENDIX B

INSTRUCTIONS FOR INSTALLING AND CONFIGURING

SOFTWARE

This appendix contains instructions for installing and configuring ClockerPro

and Clocker, Kermit-Lite, and connectivity software such as Dunce (Dial-up

Networking Connection Software).

ClockerPro and Clocker

ClockerPro for Windows95 and Clocker for Windows 3.1 may be downloaded

from: http://www.winnovation.com/clocker.htm. To install ClockerPro or

Clocker:

1. Click on the file clkpr311.zip (for ClockerPro) or clk2403.zip (for Clocker)

and save it to a temporary directory on your computer (such as c:\tmp).

2. Start your Web browser. Navigate to the location of clkpr311.zip.

3. Run setup.exe and follow the instructions provided.

For instructions on using ClockerPro or Clocker, select Help from the software’s

main screen. Sample schedules specific to Automatic Data Transfer System

(ADTS) operation are provided in c:\oms\config\shc95.clk (for ClockerPro) and

c:\oms\config\shc31.clk (for Clocker). You can open these from either program’s

File\Open menu. The polling times in these sample schedules do not reflect the

currently recommended polling/upload times for each day and will need to be

modified.

Kermit-Lite

Kermit-Lite for MS-DOS is the communications software used by the ADTS as

a backup method of file transfer. The required initialization and script files have

already been included in the ADTS software distribution. We suggest that you

install the full Kermit for MS-DOS package to have access to the latest initialization and script files as well as documentation. Kermit-Lite for MS-DOS and

Windows 3.x can be downloaded from http://www.columbia.edu/kermit/

mskermit.html. Follow the installation instructions provided with Kermit-Lite

and install it. Do not install the full Kermit-Lite package in the c:\oms directory.

Doing so might overwrite files you have already configured for your computer.

Connectivity Software

For information on installing Dunce 2.52, see the instructions file adts-shc.txt.

You can download Dunce 2.52 from http://www.gf-inter.net/serv03.htm.

Serv-U is available as shareware (registration is $25) from http://www.catsoft.com/.

INSTRUCTIONS FOR INSTALLING AND CONFIGURING SOFTWARE B 1

APPENDIX C

AUTOMATED DATA QUALITY CHECKS

This appendix contains a detailed description of automated data quality checks

that the Data Collection Center (DCC) performs on actual (observed) station

data groups. These automated data quality checks:

1. Check for data that are out of range.

2. Check for data with unusual rates of changes.

3. Check how many hours of data are missing. Uses interpolation to estimate

hourly values if only 1 hour is missing. If more than one hour is missing, the

data is marked as missing and there is no attempt to estimate the data.

4. Assign quality control flags to each ozone value. 

Quality assurance/quality control (QA/QC) flags enable whoever is reviewing

the data to quickly identify problems and understand their source and severity. The flags are written to the observation file, where they can be reviewed by

the DCC (and also by the end- user who has an observation file). The following table shows the correlation between flag type and data integrity.

5. Extrapolate a single missing value (i.e., estimate new values from missing or

bad values).

6. Assign specific QA/QC criteria to the data. For example, for the Greenwich,

CT, monitoring station, the proposed maximum allowed ozone level during

11:00 a.m. to 6:00 p.m. is 197 parts per billion. The QA/QC program checks

to see if ozone data during this time fall within the allowable concentration.

For further information on proposed quality assurance values that may be

incorporated into the DCC software, see sample criteria at

http://envpro.ncsc.org/oms/pub/SiteInfo/03-QC-table.html.

7. Generate a quality control report that summarizes the total amount of good,

suspect, bad, and missing data by station. This report is reviewed every time a

polling cycle is completed by a DCC staff member before the data are released

to the public. Each “suspect” or “severe” flag set by the automated program is

inspected in the context of surrounding data both in time and in space.

AUTOMATED DATA QUALITY CHECKS C 1

1 G Good Data 

2 K Suspect Range or Sample Number

2 R Suspect Rate of Change

3 E Estimated

4 M Missing (-999 will be used for the missing data value)

5 B Bad (Severe Range or other problem)

Level Flag Meaning

Tip! 

If you open an observation

file, you will see that each

monitoring station has two

lines of data. The first line

contains the ozone data values. The second line contains QA/QC flags directly

beneath their respective

ozone data values. The flags

signify whether the data

value is good, suspect, estimated, missing, or bad. 
8. Document the level of QA/QC effort in the observation file. The observation

file provides information on the level of QA/QC effort at the DCC: 

• <qc_level>=0 means that no QA/QC was done.

• <qc_level>=1 means that the DCC performed an automated

QA/QC check of the data.

• <qc_level>=2 means the staff reviewed the automated QA/QC.

Note! 

The DCC performs a “mini-check” on forecast data, but the data are

not flagged. Forecast data should be inspected before use. 

C 2 APPENDIX C
2Printed on paper containing at least 

30% postconsumer recovered fiber.