System Disruption Blacks Out Much of West

Tuesday, July 2, 1996 | 11:59 a.m.

The problem knocked out a PacifiCorp grid that delivers 4,500 megawatts of power from the Pacific Northwest to Utah, Wyoming, Montana, Oregon, Idaho, Washington and northern California.

Four 500 megawatt coal-fired power plants in Rock Springs, Wyo., inexplicably went off-line about 2:30 p.m. MDT, and at the same time, seven hydro-plants along the Colorado River aquaduct also apparently fell off-line, said Gary Donnelly, a spokesman for PacifiCorp in Portland, Ore.

Pacific Gas & Electric spokesman Len Anderson said reports of power outages were coming in from Los Angeles to Boise, Idaho.

Thousands of homes and businesses throughout Northern California were affected. The California Highway Patrol said traffic signals were out in scattered areas throughout Northern California. A power outage at a Daly City, Calif., Bay Area Rapid Transit station also created delays.

PG&E officials said they did not know how many customers were affected and when power would be restored.

"I would have to say this is big," Donnelly said. "This is a significant system disturbance. How far it extends and the length of it's duration, I can't tell you that now."

The blackout came on a day when power resources were stretched by record hot temperatures. The mercury hit 102 Tuesday afternoon at the Salt Lake International Airport, breaking a six-year old record high for the date.