The 8-Hour National Ambient Air Quality Standard for Ozone became effective throughout Louisiana on June 15, 2004. The standard is 84 parts per billion (ppb). Compliance with the standard is measured by the 3- year average of the 4th highest reading each year at each monitor within an area. Stated differently, the 3- year average of the 4th highest 8-hour reading at each monitor within an area must equal 84 ppb or less. Currently, the monitor at Kenner, Louisiana is in danger of causing the New Orleans Metropolitan Statistical Area (MSA) be in nonattainment of the standard. According to Louisiana Department of Environmental Quality records, the Kenner monitor has had readings of 87, 85, 83, and 81 parts per billion during the 2005 ozone season which runs from May through October. Due to the readings over the past two years, the Kenner monitor cannot exceed 83 ppb as the 4th high reading this year, or the 3-year average will be greater than 84 ppb. Thus, if that monitor has an 8-hour average of 84 ppb or greater on two more days during this ozone season, then the whole MSA will go into nonattainment. The New Orleans MSA consists of Jefferson, Orleans, Plaquemines, St. Bernard, St. James, St. Charles, St. John the Baptist, and St. Tammany parishes.
Nonattainment status would trigger a number of additional regulatory requirements for businesses within the area, as well as transportation planning requirements and potential restrictions for municipalities.
The Louisiana Department of Environmental Quality publishes notices of Ozone Action Days on its website: http://www.deq.louisiana.gov/evaluation/ozone/oz_today.asp.
Moreover, the Department also has a list of do’s and don’ts to help citizens and business assist in avoiding ozone exceedances. That action guide is available at http://www.deq.louisiana.gov/evaluation/o3act/oap_you.htm.