The US Department of Justice, the Environmental Protection Agency and Louisiana Department of Environmental Quality (LDEQ) [official websites] reached a settlement agreement [text, PDF] with ExxonMobil [corporate website] Tuesday over violations of the Clean Air Act from their chemical, olefins, polymer and plastics manufacturing facilities located in or near Baytown, Texas, Beaumont, Texas, Baton Rouge, Louisiana, and Mont Belvieu, Texas.

ExxonMobil will be required to pay a civil penalty of $2.5 million, $470,00 of which will go to the LDEQ and the remainder to the US and to pay for air pollution reduction measures. ExxonMobil will also be required to invest in the installation and operation of air pollution control and monitoring devices at 26 industrial flares located at five facilities in Texas and three facilities in Louisiana, which is expected to cost about $300 million.

ExxonMobil will also be required to spend at least $2,572,000 various Federal Supplemental Environmental Projects and State Beneficial Environmental Projects. This includes planting 1,458 trees in the city of Baytown, Texas, providing upgrades to LDEQ stationary ambient monitoring stations, and providing the LDEQ with a $1.5 million mobile air monitoring laboratory.

The settlement will be subject to a 30-day public comment period and will then need final court approval before being enacted.