This web service contains the following layer: OzoneReview35Cities_with2000to2014data. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (available through the online link provided above) and viewing the layer description.

This web service contains the following layer: CBSA35_2014OzoneAQI_data. Full FGDC metadata record for this layer may be found by clicking the layer name at the web service endpoint (available through the online link provided above) and viewing the layer description.

This web service contains the following layer: CBSA35_2014OzoneAQI_data. Full FGDC metadata record for this layer may be found by clicking the layer name at the web service endpoint (available through the online link provided above) and viewing the layer description.

This web service contains the following layers: Ozone 2008 NAAQS NAA State Level and Ozone 2008 NAAQS NAA National Level. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NAA2008Ozone8hour/MapServer) and viewing the layer description. These layers identify areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for criteria air pollutants and have been designated "nonattainment” areas (NAA)". The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short-term (24-hour) exposure levels. The methods and allowable concentrations vary from one pollutant to another, and within NAAQS revisions for each pollutant. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. The set of limits based on human health is called primary standards. Another set of limits intended to prevent environmental and property damage is called secondary standards. A geographic area that meets or does better than the primary standard is called an attainment area; areas that don't meet the primary standard are called nonattainment areas. In some cases, a designated nonattainment area can include portions of 2, 3, or 4 states rather than falling entirely within a single state. Multi-state areas have had different state portions handled through up to 3 separate EPA regional offices. The actions of EPA and the state governments for separate portions of such areas are not always simultaneous. While some areas have had coordinated action from all related states on the same day, other areas (so-called "split areas") have had delays of several months, ranging up to more than 2 years, between different states. EPA must designate areas as meeting (attainment) or not meeting (nonattainment) the standard. A designation is the term EPA uses to describe the air quality in a given area for any of the six common air pollutants (criteria pollutants). After EPA establishes or revises a primary and/or secondary National Ambient Air Quality Standard (NAAQS), the Clean Air Act requires EPA to designate areas as "attainment" (meeting), "nonattainment" (not meeting), or "unclassifiable" (insufficient data) after monitoring data is collected by state, local and tribal governments. Once nonattainment designations take effect, the state and local governments have three years to develop implementation plans outlining how areas will attain and maintain the standards by reducing air pollutant emissions. For further information please refer to: https://www3.epa.gov/airquality/greenbook/index.html. Questions concerning the status of nonattainment areas, their classification and EPA policy should be directed to the appropriate Regional

This web service contains the following layers: Ozone 2008 NAAQS NAA State Level and Ozone 2008 NAAQS NAA National Level. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NAA2008Ozone8hour/MapServer) and viewing the layer description. These layers identify areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for criteria air pollutants and have been designated "nonattainment” areas (NAA)". The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short-term (24-hour) exposure levels. The methods and allowable concentrations vary from one pollutant to another, and within NAAQS revisions for each pollutant. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. The set of limits based on human health is called primary standards. Another set of limits intended to prevent environmental and property damage is called secondary standards. A geographic area that meets or does better than the primary standard is called an attainment area; areas that don't meet the primary standard are called nonattainment areas. In some cases, a designated nonattainment area can include portions of 2, 3, or 4 states rather than falling entirely within a single state. Multi-state areas have had different state portions handled through up to 3 separate EPA regional offices. The actions of EPA and the state governments for separate portions of such areas are not always simultaneous. While some areas have had coordinated action from all related states on the same day, other areas (so-called "split areas") have had delays of several months, ranging up to more than 2 years, between different states. EPA must designate areas as meeting (attainment) or not meeting (nonattainment) the standard. A designation is the term EPA uses to describe the air quality in a given area for any of the six common air pollutants (criteria pollutants). After EPA establishes or revises a primary and/or secondary National Ambient Air Quality Standard (NAAQS), the Clean Air Act requires EPA to designate areas as "attainment" (meeting), "nonattainment" (not meeting), or "unclassifiable" (insufficient data) after monitoring data is collected by state, local and tribal governments. Once nonattainment designations take effect, the state and local governments have three years to develop implementation plans outlining how areas will attain and maintain the standards by reducing air pollutant emissions. For further information please refer to: https://www3.epa.gov/airquality/greenbook/index.html. Questions concerning the status of nonattainment areas, their classification and EPA policy should be directed to the appropriate Regional

This web service contains the following layers: Ozone 1997 NAAQS NAA State Level and Ozone 1997 NAAQS NAA National Level. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NAA1997Ozone8hour/MapServer) and viewing the layer description. These layers identify areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for criteria air pollutants and have been designated "nonattainment” areas (NAA)". The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short-term (24-hour) exposure levels. The methods and allowable concentrations vary from one pollutant to another, and within NAAQS revisions for each pollutant. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. The set of limits based on human health is called primary standards. Another set of limits intended to prevent environmental and property damage is called secondary standards. A geographic area that meets or does better than the primary standard is called an attainment area; areas that don't meet the primary standard are called nonattainment areas. In some cases, a designated nonattainment area can include portions of 2, 3, or 4 states rather than falling entirely within a single state. Multi-state areas have had different state portions handled through up to 3 separate EPA regional offices. The actions of EPA and the state governments for separate portions of such areas are not always simultaneous. While some areas have had coordinated action from all related states on the same day, other areas (so-called "split areas") have had delays of several months, ranging up to more than 2 years, between different states. EPA must designate areas as meeting (attainment) or not meeting (nonattainment) the standard. A designation is the term EPA uses to describe the air quality in a given area for any of the six common air pollutants (criteria pollutants). After EPA establishes or revises a primary and/or secondary National Ambient Air Quality Standard (NAAQS), the Clean Air Act requires EPA to designate areas as "attainment" (meeting), "nonattainment" (not meeting), or "unclassifiable" (insufficient data) after monitoring data is collected by state, local and tribal governments. Once nonattainment designations take effect, the state and local governments have three years to develop implementation plans outlining how areas will attain and maintain the standards by reducing air pollutant emissions. For further information please refer to: https://www3.epa.gov/airquality/greenbook/index.html. Questions concerning the status of nonattainment areas, their classification and EPA policy should be directed to the appropriate Regional

This web service contains the following layers: Ozone 1997 NAAQS NAA State Level and Ozone 1997 NAAQS NAA National Level. Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NAA1997Ozone8hour/MapServer) and viewing the layer description. These layers identify areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for criteria air pollutants and have been designated "nonattainment” areas (NAA)". The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short-term (24-hour) exposure levels. The methods and allowable concentrations vary from one pollutant to another, and within NAAQS revisions for each pollutant. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. The set of limits based on human health is called primary standards. Another set of limits intended to prevent environmental and property damage is called secondary standards. A geographic area that meets or does better than the primary standard is called an attainment area; areas that don't meet the primary standard are called nonattainment areas. In some cases, a designated nonattainment area can include portions of 2, 3, or 4 states rather than falling entirely within a single state. Multi-state areas have had different state portions handled through up to 3 separate EPA regional offices. The actions of EPA and the state governments for separate portions of such areas are not always simultaneous. While some areas have had coordinated action from all related states on the same day, other areas (so-called "split areas") have had delays of several months, ranging up to more than 2 years, between different states. EPA must designate areas as meeting (attainment) or not meeting (nonattainment) the standard. A designation is the term EPA uses to describe the air quality in a given area for any of the six common air pollutants (criteria pollutants). After EPA establishes or revises a primary and/or secondary National Ambient Air Quality Standard (NAAQS), the Clean Air Act requires EPA to designate areas as "attainment" (meeting), "nonattainment" (not meeting), or "unclassifiable" (insufficient data) after monitoring data is collected by state, local and tribal governments. Once nonattainment designations take effect, the state and local governments have three years to develop implementation plans outlining how areas will attain and maintain the standards by reducing air pollutant emissions. For further information please refer to: https://www3.epa.gov/airquality/greenbook/index.html. Questions concerning the status of nonattainment areas, their classification and EPA policy should be directed to the appropriate Regional

This web service layer, Ozone 8-hr (2015 standard), displays identified state level areas where ground-level ozone have not met the National Ambient Air Quality Standards (NAAQS) established in 2015 for ground-level ozone and have been designated "nonattainment” areas (NAA)". Full FGDC metadata records for each layer may be found by clicking the layer name at the web service endpoint (https://gispub.epa.gov/arcgis/rest/services/OAR_OAQPS/NonattainmentAreas/MapServer) and viewing the layer description. The data are updated weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" pollutants. Under provisions of the Clean Air Act, which is intended to improve the quality of the air we breathe, EPA is required to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. For each criteria pollutant, there are specific procedures used for measuring ambient concentrations and for calculating long-term (quarterly or annual) and/or short-term (24-hour) exposure levels. The methods and allowable concentrations vary from one pollutant to another, and within NAAQS revisions for each pollutant. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. The set of limits based on human health is called primary standards. Another set of limits intended to prevent environmental and property damage is called secondary standards. A geographic area that meets or does better than the primary standard is called an attainment area; areas that don't meet the primary standard are called nonattainment areas. In some cases, a designated nonattainment area can include portions of 2, 3, or 4 states rather than falling entirely within a single state. Multi-state areas have had different state portions handled through up to 3 separate EPA regional offices. The actions of EPA and the state governments for separate portions of such areas are not always simultaneous. While some areas have had coordinated action from all related states on the same day, other areas (so-called "split areas") have had delays of several months, ranging up to more than 2 years, between different states. EPA must designate areas as meeting (attainment) or not meeting (nonattainment) the standard. A designation is the term EPA uses to describe the air quality in a given area for any of the six common air pollutants (criteria pollutants). After EPA establishes or revises a primary and/or secondary National Ambient Air Quality Standard (NAAQS), the Clean Air Act requires EPA to designate areas as "attainment" (meeting), "nonattainment" (not meeting), or "unclassifiable" (insufficient data) after monitoring data is collected by state, local and tribal governments. Once nonattainment designations take effect, the state and local governments have three years to develop implementation plans outlining how areas will attain and maintain the standards by reducing air pollutant emissions. For further information please refer to: https://www.epa.gov/oar/oaqps/greenbk/index.html. Questions concerning the status of nonattainment areas, their classification and EPA policy should be directed to the appropriate Regional Offices (https://www.epa.gov/oar/oaqps/greenbk/regcntct.html).

This dataset includes the number of days in 2017 that the maximum 8-hour average ozone concentration predicted by the Community Multiscale Air Quality modeling system (CMAQ) exceeds a threshold value of 80 ppb. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

This dataset includes the number of days in 2017 that the maximum 8-hour average ozone concentration predicted by the Community Multiscale Air Quality modeling system (CMAQ) exceeds a threshold value of 70 ppb. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).