Another Attack Discovered at an Electricity Substation Near the Border -- and One Congressman Says It's 'Only a Matter of Time' Before More Attackers 'Exploit This Vulnerability

A 50,000 gallon diesel fuel tank at a critical transformer substation south of Tucson near a border town that has been the center of immigration news lately was the target of an attack last week, but the make-shift bomb failed to cause a major explosion or power outage.

More than 30,000 Arizona residents could have been stripped of all access to power for their homes and businesses, for an unknown period of time, if the explosive device had knocked out their critical transformer substation.

FBI Bomb technicians respond to the Nogales transmission plant after an incendiary device was found at the critical electricity facility, which services 30,000 people in the surrounding area (Image source: Nogales International).

Instead, the device -- roughly described by local police as a homespun device that could fit in the palm of your hand -- failed to ignite the diesel fuel in one of the storage tanks for four back-up power generators housed at the site.

"On the morning of June 11th, an employee discovered that a hole bad been cut in the fence of a substation that serves Nogales AZ and that the remains of a crude incendiary device was found at the base of a diesel fuel tank," Joe Salkowski, UniSource Energy Services spokesman told TheBlaze.

Reports last week indicated a large explosion had occurred at the plant, but Salkowski said, "The device caused a small, temporary fuel leak and blackened a small section of the surface of the tank, but did not cause any serious damage to the fuel tank."

The targeted facility is an electric substation just a few miles north of the U.S.-Mexico border, that provides service to the city of Nogales and the surrounding areas. Most of the power delivered to the customers comes through that substation by way of a transmission line -- the large electric cables you see lining the highway and crossing the country -- that links the Nogales plant to a larger substation the Tucson area.

"They were able to gain access to the facility illegally," Nogales police Lt. Carlos Jimenez said. "They had some working knowledge of what that tank is or how it works."

The 138-kilovolt transmission step-down facility isn't responsible for generating power for the area; it takes power transmitted through the larger electricity lines and "steps" it down, or lowers the voltage, so it can be used by consumers. When sending power from generation facilities to communities that use it, the voltage must be "stepped up" to make it across the long distances.

However, UniSource Energy Services, a subsidiary of UNS Energy Corporation and owner of the Valencia Plant, does maintain four small combustion turbine generators at the Nogales plant, which can be operated on natural gas or diesel fuel, to provide back-up power in case of emergency or during peak usage times.  Those diesel storage tanks were the target of the June 11 attack.

Local 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, Arizona Central reported.

[sharequote align="center"] "It seems only a matter of time before more sophisticated and perhaps more malevolent enemies seek to exploit this vulnerability..." [/sharequote]

Nogales officials called the FBI, the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives and the state Department of Public Safety for help. Special Agent Perryn Collin, a spokesperson for the Phoenix division of the FBI, told TheBlaze "the investigation is ongoing" and "it will be a while before we release anything; several investigative leads need to be covered," but said they are working in conjunction with the U.S. Attorney's office as well as the ATF on the case.

"The reason for the high-scale response is the plant is an electrical substation and critical to the area," Jimenez said Thursday. "The whole city of Nogales could have been compromised."

Nogales has been at the center of recent media coverage after pictures surfaced showing nearly a thousand immigrant children stuffed into its border facility.

Police identified no suspects or witnesses, and said there were no signs of vandalism common with domestic extremist groups such as the Earth Liberation Front, or ELF, according to Arizona Central. The FBI has designated the ELF as a domestic terrorism group, which the bureau blames for arson attacks on homes, power facilities and other symbols of urbanization.

But utilities providers across the nation were reminded of their vulnerability to sabotage in April 2013, when attackers cut emergency communication lines to a crucial transformer substation for Silicon Valley before shooting sniper rifles at the extra high voltage transformers for 19 minutes.

The San Jose attack was described as "the most significant incident of domestic terrorism involving the grid that has ever occurred," by then-Federal Energy Regulatory Commission chairman Jon Wellinghoff and it took 27 days to get the substation back online.

Salkowski told TheBlaze the Nogales plant operations were not affected by the incendiary device's damage.

When compared side-by-side, the San Jose incident was an example of a coordinated, calculated attack, while the Nogales incident could be considered unsophisticated, especially since the attackers failed to understand diesel fuel has a high flash point and is difficult to ignite.

But lawmakers and utilities providers are eager to see more attention paid to this brand of domestic attack before thousands are affected.

"It's unclear whether these are sophisticated attacks or not, but they illustrate the growing awareness of America's vulnerability related to the grid,"Congressman Trent Franks (R-AZ), told TheBlaze. "It seems only a matter of time before more sophisticated and perhaps more malevolent enemies seek to exploit this vulnerability,"

Rep. Franks has two bills, CIPA and the SHIELD Act, awaiting subcommittee vetting in the House which would bolster electric utility resilience against physical attacks and natural disasters.

TheBlaze asked Salkowski if UniSource Energy Services had security cameras rolling during the incident Wednesday, and what - if any - security upgrades the company was planning.

"We are currently reviewing security in place at that facility as well as others in the area in hopes of identifying potential upgrades or anything that could be done to prevent similar incidents in the future," he said.

--

(H/T: Arizona Central)

Follow Elizabeth Kreft (@elizabethakreft) on Twitter. 

We will be discussing this story and all the day's news on our live BlazeCast with Editor-in-Chief Scott Baker (@bakerlink) beginning at 3:00pm ET: