Pipeline that exploded near Hwy 280 had been damaged by backhoe

KTVU
KTVU
KTVU

SAN MATEO Co., Calif. — A PG&E natural gas pipeline that exploded during pressure testing on Sunday afternoon, causing a mudslide across Interstate Highway 280 in
Woodside, was likely damaged by a backhoe, a utility spokesman said
Monday.

PG&E crews this morning were determining how to extract and
replace the damaged section of Line 132, which ruptured during hydrostatic
testing on a knoll above Highway 280 near Farm Hill Boulevard at about 3:20
p.m., PG&E spokesman David Eisenhauer said.

A preliminary investigation indicated that the section of pipe
that ruptured had been damaged by a backhoe sometime after the line was
installed in 1947. PG&E is looking into when that damage might have occurred
and what agency might have been responsible, Eisenhauer said.

The explosion left a 5-foot-by-5-foot crater in the hillside, and
water from inside the pipeline caused a mudslide that reached northbound
Highway 280 and blocked two lanes for about four hours, California Highway
Patrol Officer Art Montiel said

No one was injured.

The test was being conducted as part of an ongoing safety
evaluation of natural gas transmission lines in "high consequence" or highly
populated areas, Eisenhauer said.

"That's exactly why we do these type of safety tests, to find
weaknesses in the pipeline," Eisenhauer said.

PG&E crews have conducted pressure tests on more than 120 miles of
pipeline since April.

Eisenhauer said no homes or buildings were damaged by Sunday's
rupture, and that the utility employs different testing strategies on
pipelines that run directly through neighborhoods, such as placing cameras or
"pigs" that run inside the pipes to detect corrosion or faulty seams.

Last week, PG&E found a 1-millimeter leak in Line 132 in Palo
Alto, and last month a line ruptured in Bakersfield during hydrostatic
testing.

A faulty seam on Line 132 ruptured in San Bruno on Sept. 9, 2010,
causing an explosion that killed eight people and damaged 38 homes.

Photo caption: The ruptured pipeline. (KTVU)