DES MOINES, Iowa (AP) — A northeastern Iowa dairy that makes cheese has agreed to pay a $100,000 penalty and install expensive pollution control equipment for violating air-quality rules for a dozen years.

The Iowa Attorney General's office said in a written statement Friday that Prairie Farms Dairy in Luana admitted to the violations in a consent decree signed earlier this week. The plant formally operated under the name Swiss Valley Farms. Prairie Farms and Swiss Valley merged in April 2017.

State prosecutors and environmental officials say the plant removed an air pollution control device called a baghouse in 2004 without seeking a permit. In 2016, it installed a dryer stack fan that reduced emissions.

As part of the consent decree, Prairie Farms has agreed to install a baghouse at a cost of $1.4 million.