SANTA MARGARITA, Calif. -

Crews with Pacific Gas and Electric (PG&E) performed cleaning on several transmission lines in San Luis Obispo County on Thursday. The maintenance was done airborne using high-powered sprayers affixed to a helicopter. The 30-foot sprayers shoot high-pressure water steam, which rapidly clean the equipment.

PG&E says the cleaning is needed to reduce concentrations of dirt and other contaminants that build up throughout the year on the lines. The buildup is especially dramatic in the area due to the location along the Pacific Ocean.

The operation helps the power company improve the safety and reliability of its electric system. PG&E says it has seen nearly a 70 percent reduction in the number of momentary outages on the lines that were cleaned.

On Thursday, crews cleaned lines that travel from San Luis Obispo to Interstate 5 in the San Joaquin Valley. Crews will remain in the area and continue the cleaning operation over the next several days.