Muscatine's sulfur dioxide pollution woes continued in the first three months of 2013 with eight exceedances of national air quality standards recorded as of March 12.
Three of the National Ambient Air Quality (NAAQ) exceedances were recorded at the Musser Park monitor and five others at the East High (Garfield) monitor operated by the Iowa Department of Natural Resources.
For the period January 1 through March 12, a total of nine air quality exceedances were recorded in the entire state, the eight for SO2 pollution in Muscatine and one for PM 2.5 (fine particulate matter less than 2.5 microns in diameter) recorded in Sioux City.
CLICK HERE to download the NAAQ exceedance report from the Iowa DNR.
The U.S. Environmental Protection Agency has proposed designating the entire county in non-attainment for sulfur dioxide pollution, which would bring tougher regulations on new and existing businesses to lower SO2 emissions in Muscatine County. The Iowa DNR and the governor tried unsuccessfully to avoid any non-attainment designation two years ago, suggesting to the EPA the county be designated as "unclassifiable."
Under the non-attainment designation proposed by the EPA, existing SO2 pollution sources in the county could be required to reduce their emissions, and new sources that emit sulfur dioxide above certain levels would be required to be built with air pollution controls having the lowest sulfur dioxide emissions technically possible.
The 75 parts per billion (PPB) standard set by the EPA in June 2010 is designed to protect against high short-term SO2 exposures, which can be particularly harmful to children, the elderly and those individuals with asthma, bronchitis, emphysema and other lung and heart diseases.
In its response to Branstad's letter seeking to avoid non-attainment designation, EPA Regional Administrator Karl Brooks outlined the reasons for the federal non-attainment action, pointing out that even assigning a zero emission level to disputed readings from an air monitor at Musser Park, the result was a sulfur dioxide level of 123 parts per billion, or 150 percent of the National Ambient Air Quality standard.
EPA gave the state until April 8 to provide it with additional information for consideration prior to EPA finalizing the non-attainment recommendation. EPA intends to finalize the non-attainment designation in June.
The Iowa DNR is now arguing that a much smaller area need be classified as in non-attainment. The area proposed by the Iowa DNR includes only the general city boundaries rather than the entire county.
Muscatine's SO2 pollution levels have caused numerous exceedances of National Ambient Air Quality Standards (NAAQS) in the past three years. In 2012, 35 of 39 NAAQS exceedances in Muscatine County were from high SO2 levels.
