Homeowner Sarah Reveley took these photos of old CPS Energy transformers in the Alamo Heights Area. Photos courtesy of Sarah Reveley

Leaky transformers worry residents

By Tony Cantú
Contributing Writer

CPS Energy utility officials recently stopped by the most recent Alamo Heights City Council meeting to assuage concerns of chemical-leaking transformers in the wake of concerns by a local resident reporting a leak on her property.

The bottom line of their Aug. 25 presentation: The risk of contamination is negligible.

Still, officials of utility CPS Energy conceded they have no way of knowing which of its transformers – the utility counts more than 200,000 of the small energy grids among its stock – are most likely to leak since records aren’t formally kept.

The issue came to light Aug. 5, when resident Sarah Reveley of the 400 block of Corona dashed off a mass e-mail to fellow residents, City officials and media outlets alike. Her electronic communiqué had the desired effect – including a write-up in the San Antonio Express-News – in calling attention to transformers with potential to spill potentially harmful Polychlorinated Biphenyls – commonly known as PCBs.

“Okay, forgive me for sounding alarmist, but Hazmat was here today and bulldozed 25 percent of my front yard, a foot deep,” Reveley wrote in her first e-mail after CPS Energy responded to her report of transformer leakage. “Even took the rocks. Put it all in big barrels and sealed it tight.”

In a subsequent telephone interview, CPS Energy senior environmental analyst Doris Cooksey said such disposal was common practice to ensure safety. She acknowledged some older transformers might have been inadvertently exposed to PCBs before a ban on the chemical’s usage in the 1970s through shared tools that may have been exposed at other job sites.

“What happened in the industry is that when transformers were handled, you could have a common tool or a common hose used on them at the manufacturer,” Cooksey said. “We never thought residential transformers had any kind of contamination, but we had some that did. We treat every spill as if it does.”

A worker from CPS Energy removes groundcover from near a transformer in Alamo Heights. Photos courtesy of Sarah Reveley

“Residential transformers were not on the same scale of what you would call high-risk,” Cooksey said. Powered by mineral oil, even cross-contaminated transformers offer negligible risk, she said.

But she conceded CPS Energy doesn’t have a handle on where older transformers are located or even their exact number. However, she noted each transformer is identified with a manufacturing plate showing its date of production.

“One of the things they focused on is our records, and why we don’t know the age of transformers and how many there are out there,” Cooksey said of residents expressing concern at the meeting. She said CPS Energy has about 200,000 transformers in its service territory, including about 700 – one out of every four homes – in Alamo Heights.

“Prior to the 1990s, almost all our records were kept on paper,” she said. “Going through thousands of records a year would take a tremendous amount of time.”

She said CPS Energy statistics bear out the low risk. A small fraction of the up to 275 leaky transformers found each year show a level of PCBs that the Environmental Protection Agency deems high – at least 500 parts per million, Cooksey said.

“We have about 250 to 275 spills a year which also includes commercial transformers,” she said. “Eighty-six percent of them don’t contain any PCBs at all, just mineral oil and 13 percent have low levels or trace amount of PCBs. That leaves 1 percent of transformers considered by the EPA as having a high level of PCBs.”

Further assuaging concerns, she noted transformers are now removed through attrition. What’s more, when utility poles need replacement, transformers are replaced as a matter of routine. And as for the unit that sparked the issue – the circa-1958 model dug up at Reveley’s home – Cooksey said laboratory tests showed no trace of PCBs. The homeowner’s transformer was merely leaking mineral oil, she said.

Notwithstanding the emergence of a handful of concerned residents reacting to Reveley’s e-mail, Alamo Heights Public Works Director Shawn Eddy said the outcome – in the form of the CPS presentation – was positive: “I don’t want people to be afraid of their transformers,” he said.