The violations of the Clean Air Act include $635,000 for failing to install air pollution controls and $1.4m that the company has already spent on equipment necessary to reduce emissions.
The settlement requires the facility to monitor emissions and provide quarterly reports to EPA.
Federal investigators found that certain types of equipment, such as cereal coaters and dryers, were emitting volatile organic compounds (VOCs) without required pollution-reducing controls.
The additional $1.4m was spent in 2012 on the installation and operation of equipment that captures and controls emissions, reducing VOCs from the facility’s operations line by 95%.
Post announced in April 2013 that it would close the Modesto facility by September 2014 but stressed the decision was not related to the environmental issues resolved by the settlement.
Ralcorp Holdings purchased Post Holdings in 2008 but split off from the company in 2012.