Exxon Mobil will pay $2.5 million in fines for flaring gases at eight plants along the Gulf Coast... [and] will spend about $300 million as part of the settlement to install gas recovery and other new monitoring and pollution control technologies at the petrochemical plants in Louisiana and Texas...

The agencies also settled a second case involving air pollution violations with PDC Energy, a Colorado oil and gas company whose storage tanks were found to be leaking smog-forming compounds. The company also was fined $2.5 million, which will be shared by Colorado and the federal government... [The company] settlements resolve allegations that Exxon and PDC Energy violated the federal Clean Air Act by releasing harmful pollutants.

In the case of PDC, the company has agreed to spend about $18 million to upgrade systems. The Exxon settlement is expected to reduce releases of volatile organic compounds by more than 7,000 tons per year and reduce toxic air pollutants like benzene by more than 1,500 tons per year... "These investments... will help improve flare efficiency at these chemical facilities, which are among the largest petrochemical complexes in the world,” Aaron Stryk, an Exxon spokesman said in a statement. “Exxon Mobil complies with environmental laws, regulations and permits.”