The U.S. Environmental Protection Agency and the U.S. Department of Justice announced Tuesday that Sioux City-based Terra Industries Inc., one of the nation’s largest producers of nitric acid and nitrogen fertilizers, has agreed to pay a total of $625,000 in civil penalties to settle a series of alleged violations of the federal Clean Air Act at nine of its plants in Iowa, Mississippi and Oklahoma.

As part of the settlement, Terra will also spend an estimated $17 million to install and implement new controls and technologies that are expected to reduce harmful nitrogen oxide emissions at its facilities by at least 1,200 tons per year.
 
According to the consent decree, Terra allegedly constructed, modified and operated its various facilities without obtaining appropriate pre-construction and operating permits, and without installing best available control technology for controlling air pollution. Terra also allegedly violated the Clean Air Act by failing to comply with applicable air emission limits and ongoing requirements for emissions monitoring, recordkeeping and reporting at some of its facilities.

The company will pay $325,000 to the federal government, and $100,000 each to the state of Iowa, the state of Mississippi and the Oklahoma Department of Environmental Quality, which are named as co-plaintiffs in the action filed Wednesday in U.S. District Court in Sioux City.
 
Terra’s nine plants covered by the settlement include four nitric acid plants at Yazoo City, Miss.; two each at Sergeant Bluff, Iowa, and Verdigris, Okla.; and one at Woodward, Okla. Terra was acquired last year by CF Industries for $4.7 billion.
 
The consent decree, which is subject to a 30-day public comment period and final court approval, is available at: www.justice.gov/enrd