United States engine maker Cummins is facing steep fines for violated of the Clean Air Act following accusations of emissions test cheating. The US Environmental Protection Agency and Department of Justice have announced the company is paying a $1.05 billion penalty for "using illegal defeat devices that reduced the effectiveness of the pollution control systems on more than 500,000 heavy-duty diesel engines". The move is the largest ever Clean Air Act penalty resulting from civil violations. In addition to the penalty, Cummins has agreed to pay $290 million toward projects to further reduce diesel emissions and contribute to improving air quality. According to EPA, Cummins sold about 500,000 “defeat device” heavy-duty truck and bus engines from February 1998 to January 2018 which operated normally during emissions testing, but switched to a mode called “Pullback” while on the road. In Pullback mode, the diesel engines operated differently to reduce their effectiveness in controlling pollutants. EPA’s administrator, Andrew Wheeler, stated Cummins’ actions amounted to “corporate greed over corporate responsibility and plain old common sense”. Mr. Wheeler furthered, “this penalty is all about the health of people. We’ve imposed the largest Clean Air Act penalty ever in order to hold companies like Cummins accountable and drive home the message that protecting our environment and public health is a priority." Cummins responded by stating that the settlement was “in the best interest of the company and its stakeholders,” and requested leniency in the penalty. They have since expressed their commitment to environmental accords and are taking steps to institute rigorous testing and procedures to ensure future compliance with the Clean Air Act.