PPL: Failed line sparked underground Scranton explosion

Jan 10 - McClatchy-Tribune Regional News - Borys Krawczeniuk The Citizens' Voice, Wilkes-Barre, Pa.

The failure of a PPL Electric Utilities underground power line produced a spark, igniting an unknown pocket of gas that exploded and shook a downtown Scranton intersection last month, a spokesman for the utility said Wednesday.

Searches for flammable gas since the Dec. 28 blast turned up nothing, PPL spokesman Rich Beasley said. UGI Utilities found no traces of natural gas from its lines and PPL monitors found no other gas afterward either, Beasley said.

Beasley said the utility suspects the spark ignited "an isolated pocket of methane gas" whose origin remains unknown.

"That we don't know," he said of the gas' source. "The methane theory is only a theory."

Once the utility ruled out natural gas, it monitored the manholes looking for traces of whatever ignited.

"If we had found something, we would have done so (notified Scranton Sewer Authority) immediately," he said. "There was no sewage or sewer lines in the manhole, therefore the likelihood of the problem being sewer-related was highly unlikely, so we decided to test to narrow down the possibilities."

The vaults are entirely separate from sewer lines, he said.

Methane is a key component of natural gas. Sewage can also produce methane, according to an online Environmental Protection Agency fact sheet.

Beasley said the power line was replaced, and PPL plans to periodically check the underground vault housing the power line for gas for the next three months.

Sewer authority executive director Gene Barrett said 911 dispatchers alerted the sewer authority to the explosion immediately after it happened.

An authority crew was dispatched and remained on the scene for about three hours, but never heard any talk of methane gas.

"We would certainly be willing to cooperate," he said.

Barrett said he doubts any methane from the sewer line would have migrated to the PPL vault because they are 12 to 15 feet apart.

UGI spokesman Don Brominski said the utility is certain the gas did not come from its underground natural gas pipes.

Brominski said utility crews were on the scene after the incident with gas sensors and checked the street, the area around the manhole covers and nearby buildings. They did not detect natural gas but returned Jan. 3, repeated the tests and again found nothing, he said.

David Falchek, staff writer, contributed to this story.

bkrawczeniuk@timesshamrock.com