Grain Processing Corp. air pollution controls appear to be solving Muscatine sulfur dioxide problems

Clean air advocates hailed July 15 as "Clean Air Day for Muscatine" when Grain Processing Corporation (GPC) switched from coal to natural gas to fire its boilers.

The boiler conversion – plus a host of other pollution control improvements at the facility – now appear to be making a big difference in the city's air quality.

In the latest air monitoring report issued September 9 by the Iowa Department of Natural Resources (IDNR), Muscatine has not recorded a single exceedance of National Ambient Air Quality Standards for sulfur dioxide (SO2) since the new pollution equipment went into operation.

Up until June 7 of this year, 17 exceedances of SO2 ambient air quality standards were recorded in Iowa and all were at Muscatine air monitors.

In 2014, Muscatine air monitors recorded a total of 37 exceedances for SO2 pollution between January 1 and July 22.

The pollution control improvements also have had a similar impact on PM 2.5 (fine particulate smaller than 2.5 microns) pollution. Only one exceedance for PM 2.5 has been recorded in Muscatine so far this year, occurring prior to the boiler conversion on July 7.

GPC was fined $1.5 million and ordered to comply with state and federal air permit regulations under a court-approved consent agreement in 2014.

CLICK HERE to download the most recent ambient air quality report from the Iowa Department of Natural Resources.