Essroc Cement Co. has agreed to pay a $1.7 million penalty and invest approximately $33 million in pollution control technology to resolve alleged violations of the Clean Air Act at six of its Portland cement manufacturing plants, according to the EPA.

The settlement will reduce more than 7,000 tons of nitrogen oxides (NOX) and sulfur dioxide (SO2) pollution each year. The Nazareth, Pa.-based company also has agreed to spend $745,000 to mitigate the effects of past excess emissions from its facilities.

“These comprehensive measures at multiple Essroc facilities will achieve substantial reductions in harmful air pollution,” said Ignacia S. Moreno, assistant attorney general for the Environment and Natural Resources Division of the Department of Justice.

Under the settlement, Essroc will install state-of-the-art pollution control technology to control SO2and NOXat five of its plants and demonstrate a selective catalytic reduction system (SCR) system at two long wet kilns in its Logansport, Ind., plant. If successful, this will be the first SCRs used on long wet kilns anywhere in the world. Essroc also will permanently retire its sixth plant, located in Bessemer, Penn. This plant is currently out of operation and its permanent retirement will ensure that the facility does not restart without proper permitting under the CAA.

The settlement also requires Essroc to spend $745,000 on a mitigation project to replace old engines in several off-road vehicles at its plant sites. The replacement engines are estimated to achieve approximately a 50 to 80 percent reduction in nitrogen oxides in each engine.

Reducing air pollution from cement plants - particularly sulfur dioxide and nitrogen oxides, two key pollutants emitted from cement plants - is one of EPA’s National Enforcement Initiatives for 2011 to 2013.