Chevron(CVX -0.34%) has agreed to pay a $384,000 penalty for alleged violations of the Clean Air Act at its refinery in Salt Lake City, Utah.

The Environmental Protection Agency announced Chevron's settlement yesterday for changes the company made in operating a part of its refinery that allegedly resulted in excess emissions of nitrogen oxides.

Nitrogen oxides contribute to ground-level ozone, acid rain, and destruction of ecosystems, and that can bring lung irritants that can bring on respiratory illnesses, according to the EPA.

"It is critical that companies conduct business responsibly and obtain the proper permits before making infrastructure changes that increase emissions of air pollutants," said Mike Gaydosh, director of EPA's enforcement program in Denver. "This settlement will help ensure the company is operating in accordance with industry standards to protect the environment and the health of local communities."

The settlement also calls for Chevron to overhaul and install pollution controls on three engines at the refinery. In addition, the company will put $100,000 toward the purchase of four new compressed natural gas school buses for the Jordan School District in Salt Lake County.