US EPA Nonattainment Areas and Designations-24 Hour PM2.5 (2006 NAAQS)

this web service contains the following layers pm2 5 24hr 2006 naaqs state level and pm2 5 24hr 2006 naaqs national 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 naa2006pm2524hour 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 offices https www epa gov approved sips regional sip coordinators epa headquarters should be contacted only when the regional office is unable to answer a question