FBI Investigating AZ Power Plant Bomb

Wednesday, June 18, 2014 @ 12:06 PM gHale

A makeshift bomb placed next to a 50,000-gallon diesel tank at a power station in Nogales, AZ, last Wednesday remains under investigation by the FBI.

The incident at the plant owned by UniSource Energy Services, a subsidiary of Tucson-based UNS Energy, which is also the parent company of Tucson Electric Power, only caused minor damage and no injuries.

Bomb Explodes at AZ Power Plant
Overflowing Tank Shuts Power Plant
ND Pipelines Leak Oil, Gas into Tributary
Valve Failure Forces ND Oil, Brine Spill

Initial reports said the bomb exploded, but it did not. Nogales police Lt. Carlos Jimenez said the bomb was a crude incendiary device that could fit in a person’s hand. It ended up placed under the valve of the diesel tank and ignited, charring the steel tank.

“They were able to gain access to the facility illegally,” Jimenez said. “They had some working knowledge of what that tank is or how it works.”

The attackers failed to understand that diesel has a high flash point and is difficult to ignite.

Police identified no suspects or witnesses. They said there were no signs of vandalism common with domestic extremist groups.

Nogales officials called the FBI, the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives and the state Department of Public Safety for help. Those agencies would not comment, citing the ongoing investigation.

Police said they believe the saboteurs got into the substation sometime between 4 p.m. Tuesday, when maintenance workers locked it and left, and 8 a.m. Wednesday, when workers returned to monitor the plant.

Had there been a catastrophic explosion, as many as 30,000 customers could have lost power, Jimenez said.

The Valencia Generating Station is a small “peaking” facility, used only during the hottest hours of summer or the coldest hours of winter, when electricity demand spikes. The adjacent substation, however, is important for balancing the regional power supply.

UNS spokesman Joe Salkowski said the four turbines at the 63-megawatt plant were not running at the time of the incident. Electricity supplies did not suffer from the event or subsequent evacuation, he said.

The plant has fewer than five workers on site, with two more in nearby offices, he said.

The turbines run primarily on natural gas, supplied to the site via a pipeline. However, three of the turbines can run on diesel fuel in an emergency if natural-gas service ends up disrupted, and the diesel fuel is in two 50,000-gallon tanks, one of which suffered damage from the device.

On Thursday, law-enforcement officials said the FBI was looking at past suspicious incidents in the area, citing one near Sahuarita. In that incident, someone appeared to be trying to cut power lines, law-enforcement officials said.

Leave a Reply

You must be logged in to post a comment.