July 21, 2004
Max Jarman
The Arizona Republic
The Valley's second electric substation fire in a month on Tuesday fueled questions about whether there is something seriously wrong with the local power grid or the utility companies' operation practices.
But APS officials said Tuesday that although they have yet to determine the cause of either fire, they believe for now that the incidents are unrelated, the timing a coincidence. No evidence of sabotage has been found, and APS officials suspect equipment failure.
Two independent firms hired by APS will investigate the causes starting in August and deliver reports several months later.
"We're going to do everything we can to find out the root cause and react to the root cause," said Jack Davis, president of APS, one of the state's largest electricity providers.
He said he understood why residents are wondering what's going on at the power companies and has his own theories about what happened, which he wouldn't divulge. But he said he doesn't think the fires, or a mid-June power surge that shut down three Arizona electrical plants, are related.
"But that's why I'm bringing somebody in to take a look at it," he said.
Investigators with the Bureau of Alcohol, Tobacco, Firearms and Explosives found no evidence that outside forces contributed to Tuesday's transformer fire at APS' Deer Valley Substation. The fire shut off power to more than 50,000 homes and businesses in the northwest Valley in the wee hours, but it was restored by 8:45 a.m.
"We took a look at it and didn't find any red flags," said Thomas Mangan, a special agent with the ATF in Phoenix.
The FBI and the Joint Terrorism Task Force also toured the site near 35th Avenue and Yorkshire Drive and reached the same conclusion.
"It appeared to be equipment failure," said Susan Herskovits, an FBI special agent in Phoenix.
It was the same conclusion reached after a probe of the July 4 fire at the Westwing substation and the June 14 grid surge that shut down the Palo Verde Nuclear Generating Station west of Phoenix and several other power plants in the area.
Still, APS added guards to its smaller, 230-kilovolt substations Tuesday, similar to the Deer Valley one. The larger 500-kilovolt stations, such as Westwing, are protected by surveillance cameras.
Valley residents are still not out of the clear. APS and Salt River Project continued to call for businesses and others to cut back on electricity use between 3 and 6 p.m. for the rest of the week. A replacement transformer for the one damaged at the Deer Valley site won't be operational until perhaps Monday. A new transformer array for the Westwing site is being trucked from the Long Beach, Calif., docks but won't be operating for about three weeks.
Unlike the uproar over last summer's gasoline crunch, most political leaders in the state were muted in their concern over the weakened power grid.
Jeanine L'Ecuyer, a spokeswoman for Gov. Janet Napolitano, said the governor is confident in APS' and SRP's abilities to handle the power problems.
"She believes utilities are doing all they can," L'Ecuyer said. "She is rightfully concerned and staying in close contact with APS and SRP."
Arizona Corporation Commissioner Kris Mayes called Tuesday's fire "troubling" and pointed to the need to determine what happened and whether the recent incidents were related. Mayes said she would ask the other commissioners to call for an inspection of the security used by utilities to protect their infrastructure.
The fires also raised questions about APS' maintenance of its facilities.
"It's a maintenance issue," Arizona Corporation Commissioner Marc Spitzer said. "If things worked the way they are supposed to work, we wouldn't have any problem meeting our summer load."
Davis, however, said that after the June 14 power surge, the company inspected the Westwing transformers and found them to be working properly. The company says it adheres to maintenance standards suggested by the equipment manufacturers. There are no uniform industry standards or regulatory oversight of maintenance.
The Federal Energy Regulatory Commission has regulatory authority over the rates that transmission system operators charge other utilities to move electricity over their lines. It has no authority over the reliability of the system. The state Corporation Commission regulates electricity rates but not maintenance or reliability.
Provisions in the National Energy Bill before Congress would give the FERC the power to enforce minimum reliability standards, but the bill isn't expected to be passed any time soon.
Davis said that the outside inspector will review the company's maintenance procedures for possible flaws and shortcomings.
"I suspect they will make some recommendations," he said.
An investigation of the June 14 incident by the Nuclear Regulatory Commission raised concerns about the maintenance, testing and design of certain equipment at the Westwing station.
The NRC said it was concerned with the failure of a relay switch at the station that should have stopped the power surge from reaching the Hassayampa switchyard and shutting down Palo Verde, Red Hawk and Arlington Valley power plants. APS has replaced the relay switch with more robust equipment.
The original cause of the surge was thought to be bird excrement on a ceramic insulator.
Despite the recent incidents, Davis said the fact that the system has withstood intense pressure reflected on both customers' willingness to conserve and the fundamental stability of the power grid.
So far, fewer people have lost power than during previous major Valley monsoon storms.
"I would say the system is pretty robust," Davis said.
Reporter Chip Scutari contributed to this article.
http://www.azcentral.com/news/articles/0720substation20-ON.html