The NET database has recently been updated to Version 3.12. These web pages were taken from the NET96 Version 3.12 as of May 2000. Maps and web pages are on a whole-county basis. The detailed city and township boundaries were not used since the emissions are on a county basis and the sources are not identified by township. Since ozone is seen over a large area, it did not seem necessary to present detail below the county level.
Some counties have two MSAs within their boundaries.
Some ozone monitoring sites will almost always be out of date because states and local agencies are constantly adding and moving various sites. As a result, some monitoring sites that are on the air quality data summaries will not be on the maps and some sites on the maps may not have current air quality data. There are no designated 8- hour ozone nonattainment areas at this time.