Ameren UE owns and operates the SO2 monitoring site near its Rush Island Energy Center in Festus but the Missouri Department of Natural Resources provides oversight and quality assurance. Environmental specialists with the department conduct periodic on-site performance audits just like they do at state-run sites. 

Although the primary objective of the Rush Island project is to fulfill the consent agreement between the department and Ameren, the department also may use the data for other purposes, depending on EPA's implementation of the 2010 one-hour SO2 standard of 75 parts per billion and the strategy developed for Jefferson County to comply with the standard.


Sulfur Dioxide

EPA not only established a new one-hour standard in 2010, but it also introduced a new form for determining compliance. The new form requires three years of data — the average SO2 concentration from each hour of the year. The department and EPA calculate the design value, using the 99th percentile of one-hour daily maximum concentrations, averaged over three years.

Departmental information about sulfur dioxide (SO2)

  • Description
  • 2010 standard and related documents
Rush Island Fults IL Industrial Air Monitoring Site

Off Ivy Road
Fults, IL 62244
United States

Date Established
Pollutants Monitored
Sulfur Dioxide
38.15908, -90.22728