SACRAMENTO, CA --- The California Air Resources Board fined Silver State Trailways, a tour bus company based in Placentia, Calif., $15,750 this month for diesel engine emissions violations that occurred in 2007 and 2008.

An ARB fleet audit found that the company had not been conducting the required annual emissions inspections on their heavy-duty diesel powered tour buses, the board said. 

"Annual inspections ensure that a company's fleet is up to California' s clean air standards," said ARB Chairman Mary Nichols.

As part of the settlement, Silver State must comply with the following: 

-- Guarantee that employees responsible for conducting the inspections attend a California community college class on diesel emissions inspection procedures and provide certificates of completion within one year 

--Provide documentation to ARB that the inspections are being carried out for the next four years 

-- Update all applicable engines in the fleet with the latest low-NOx (oxides of nitrogen) software programming 

-- Ensure that all 1974 and newer diesel powered buses are up to federal emissions standards for the vehicle model year and are properly labeled with an engine certification label.