Douglas County commissioners gave approval Wednesday night to a $380 million project to upgrade the filtration system at Westar Energy’s local coal-fired plant, the Lawrence Energy Center.

Westar has proposed the construction project at the plant northwest of Lawrence to help clear the air and meet federal air-quality standards that require such upgrades by 2014.

The project is expected to begin early next year and be done by the end of 2012. As many as 350 people will be working on the expansion system to remove ash from flue gas leaving the center’s two generation units.

The particles will gather on filter bags, and once the bags are cleaned, the ash will be dropped into a hopper and properly removed. Fly ash can be sent out of the plant by train or truck and sold to be used in construction projects.

Commissioners Jim Flory and Mike Gaughan approved the project. Commissioner Nancy Thellman was absent from the meeting because of a family illness.