Power grid threat probed

SACRAMENTO —  Terrorism investigators are examining computer tampering and a bomb threat Monday that led to a lengthy evacuation of the headquarters of an agency that controls most of California’s electric transmission system.

The incident at the California Independent System Operator in Folsom followed the apparent midnight tampering with computer programs used to buy and sell power on the real-time market.

“I can confirm we are investigating this computer tampering and bomb incident,” said FBI spokeswoman Karen Ernst. She said the Sacramento Joint Terrorism Task Force has a lead on a suspect and believes that the two events may be linked. She declined to elaborate.

Neither of the incidents affected the operation of the state’s electrical grid, said Cal-ISO spokeswoman Stephanie McCorkle. Control of the network was transferred from Folsom to Cal-ISO’s Southern California operations center in Alhambra after the headquarters’ evacuation, she said.

About 500 Cal-ISO employees left the Folsom building at noon and did not return to their posts at the close of business, McCorkle said.

Two people with knowledge of Cal-ISO operations said the suspect in the computer tampering was a disgruntled employee of a Cal-ISO contractor.

Eric Saltmarsh, executive director of the California Electricity Oversight Board, which monitors Cal-ISO operations, said he was informed early Monday that computers had been breached but only commercial data had been affected.

Cal-ISO restored all systems to normal by 6 a.m. and used back-up systems to check all transactions for electricity that might have been affected by the interruption of power to some computers, Cal-ISO said in a statement.

A spokesman for Gov. Arnold Schwarzenegger said that the governor’s office had been briefed on the Cal-ISO security breach and that it had confidence in the agency’s handling of the incident.

Cal-ISO, a public benefit, nonprofit corporation, manages 25,000 miles of electrical transmission lines in California for the state’s three investor-owned utilities, including Southern California Edison Co., and operates wholesale power markets.

marc.lifsher@latimes.com