By Matt Roy, Independent Newsmedia

Following a critical incident at a local power facility, four injured firefighters are recovering from injuries while officials try to find out what went wrong.

And questions remain about who has the power to regulate such sites.

Authorities responded late last Friday to a report of smoke at the McMicken Energy Storage facility in Surprise, according to a report from the Associated Press.

When Surprise first responders determined hazardous materials may have been involved, hazmat units of the Peoria Fire-Medical Department arrived at the site near Grand Avenue and Deer Valley Road to assist.

Following what numerous reports have described as a loud explosion, four Peoria firefighters were injured at the scene – identified by city officials as Captain Hunter Clare, engineer Justin Lopez, firefighter Matt Cottini and firefighter Jake Ciulla – and were transported to local trauma centers for treatment.

As of Thursday, two had been released, while the others continued to receive in-patient care.

While the firefighters continue to recover, APS officials say they still aren’t exactly sure what happened at the facility, which housed a grid-level lithium ion battery used to store solar-derived energy for nighttime use.

“At this point in the investigation it is not clear exactly. I know a lot of people are saying there was an explosion and that it blew up, but at this point we cannot even verify if that occurred,” said Annie DeGraw, a spokeswoman for Arizona Public Services, which owns and operates the facility. “We know there was a failure and something happened, but we aren’t exactly sure what machinery caused that and what were the steps leading up to that actually taking place.”

She said APS had installed three such power storage facilities at sites in Arizona, all of which are now offline pending investigations.

“In total throughout the state we have three lithium ion batteries. We have two in the West Valley of Phoenix and we have one about 90 minutes northeast of downtown Phoenix,” Ms. DeGraw said. “The others have out of an abundance of caution been taken offline for now. And this is a typical step for someone who’s as safety focused as APS.”

The other two sites are in Buckeye near Sun City Festival and in Punkin Center, an unincorporated hamlet in Gila County south of Payson.

While APS typically provides special safety training to area first responders when installing some sensitive equipment, Ms. DeGraw could not confirm if that was the case in any of the three communities where they installed the lithium ion batteries.

Regulations?

While they were reportedly informed of the presence of lithium batteries, city officials do not have any authority to regulate APS installations within the community, according to Surprise Assistant City Manager and spokeswoman Diane Arthur.

“We were notified by APS regarding the location of the energy storage system approximately in the spring of 2016. As for permitting, the 2012 International Building Code exempts Public Service Agencies,” Ms. Arthur stated by email.

Surprise City Code105.2.3 Public Service Agencies reads: “A permit shall not be required for the installation, alteration or repair of generation, transmission, distribution or metering or other related equipment that is under the ownership and control of public service agencies by established right.”

Other municipalities, like the city of Phoenix, adhere to similar exemptions because, according to commentary provided in their code: “Utilities that supply electricity, gas, water, telephone, television cable, etc., do not require permits for work involving the transmission lines and metering equipment that they own and control … Utilities are typically regulated by other laws that give them specific rights and authority in this area.”

While installation of a fence surrounding the battery unit in Surprise – which is roughly the size of a shipping container – did require permit approval from city officials, the battery itself did not, Ms. Arthur confirmed.

But Ms. Degraw said APS did get a permit for the battery near Sun City Festival.

“When we are placing a lithium ion battery, we pull a permit and it is reviewed by the fire department and the authority-having jurisdiction, in this case, the city of Buckeye,” she said.

The apparently faulty unit is located across Grand from Asante Community Park and the Dysart Learning Center, less than a quarter-mile from home sites.

Erin Jordan, a spokeswoman for the Arizona Department of Environmental Quality, said her agency does not regulate battery storage facilities, since that technology is not known to emit pollutants into the atmosphere.

She was unsure under whose jurisdiction electric power storage facilities might fall, Ms. Jordan said.

Asked which agencies are responsible for regulating lithium ion battery installations, the APS spokeswoman also could not confirm, but said she would look into the matter.

Ms. DeGraw was not able to confirm those entities or whether APS had met those regulatory requirements as of press time.