Residents evacuated, traffic re-routed on Santa Teresa after an
initial explosion
By Lori Stuenkel
Gilroy – City officials evacuated residents from more than 15 homes for about two hours Thursday when construction crews struck a gas line, spewing a cloud of natural gas into the air.
A backhoe digging to install a traffic signal box at the intersection of Santa Teresa Boulevard and Longmeadow Drive hit the 4-inch line, a main source of natural gas to the northwest part of the city, about 11:30am, said Steve Beams, city engineering technician and inspector.
Pacific Gas & Electric shut down the leak nearly two hours later. No one was hurt in the initial explosion or during the leak, and residents returned to their homes at 1:30pm.
Before the leak was repaired, the gas could be seen, heard, and smelled from a block away. It swirled dust and debris into the air in the empty intersection after escaping the pressure of the line and encountering a stiff breeze. Although the hole that caused the leak was only an inch or two in diameter, the pressure inside the line was 40 to 50 pounds per square inch, creating a loud whoosh.
A crew from Giacalone Electrical Services in Gilroy hit the line with a backhoe on the northeast corner of the intersection. The city is in the final five months of a two-year project to widen Santa Teresa.
“It’s not like we haven’t been working around this gas line before,” Beams said. “We’ve seen it, we’ve felt it, we’ve worked around it. … It was an accident. He thought he was already past (the gas line), but it was the same color as the Charter (Cable) and Verizon lines are in that area.”
As he drove around the construction site, Beams said he could tell the backhoe was dangerously near the gas line.
“(I) turned around, and right then, they hit it,” he said.
Two Giacalone employees who were at the site of the break – one of whom said he was a “spotter” for the backhoe – said they immediately knew what had happened because of the explosion. They did not give their names.
“The first thing you notice is, you hear the “shhhh” and it blows a lot of sand in your face,” Beams said, “and you start running.”
Workers at the construction site shut off as many electrical systems in the intersection as they could, and started knocking on the doors of residents on Summerhill Circle, Woodcreek Way, Hirasaki Avenue and Morningside Circle.
“He said, ‘You need to leave right now, there’s a gas leak’,” said Saira Canales, a Summerhill resident. “I got scared.”
The man who warned Canales told her she could take her car with her, and she left right away, she said. She stood at Hirasaki and Longmeadow and watched the scene until she left for an appointment.
A PG&E spokesman did not know if service was interrupted to any customers, but estimated that two or three might be affected. All customers had service restored Thursday afternoon, he said.
Gilroy police blocked traffic on Santa Teresa in both directions, from Mantelli Drive in the south to Sunrise Drive in the north. The mess compounded headaches for some southbound drivers who already hit a detour on U.S. Highway 101 in South San Jose, where a truck spilled sulfuric acid and forced them off the freeway.
Officers and firefighters also helped evacuate residents who remained in their homes. Two fire engines and the emergency response vehicle from Sunrise Station set up a perimeter around the leak.
Fire Chief Dale Foster said the natural gas, which is lighter than air, can travel underground through small cracks or ruptures in the ground to distances of 50 to 100 feet, putting those homes directly adjacent to the gas line at risk.
“With gas filling up the area like that, it only takes a little spark to create an explosion, so really, the sealing off of the area is more a precaution for that,” PG&E Spokesman Jeff Smith said.
Officials could not estimate how much gas escaped from the line.
“There’s not really a way of measuring how much gas escapes,” Smith said. “It couldn’t have been too much because it was sealed off pretty quickly.”
The line extends from Sunrise Drive south, crossing Santa Teresa at the Longmeadow intersection, and enters Santa Teresa again at Welburn Avenue, where it extends south, Beams said.
“You’ve got 2-inch lines feeding subdivisions, so a 4-inch line is quite substantial,” he said.
PG&E workers clamped down the line, which was made of plastic, to stop the flow of gas and repair the damage.
“They had to go north and south of the actual break,” Fire Chief Clay Bentson said. “They couldn’t operate right where the break was.”
Once the damaged area was sealed off, the workers continued replacing the ruptured section of pipe into the afternoon. Police and firefighters cleared the area and opened the roads to traffic about 1:30pm.
The repair will cost “definitely over six figures,” Beams said, but could not provide a more accurate estimate. He said the repair on the broken portion of pipe would cost about $90,000, and PG&E may charge for the spilled gas.
Crews could begin paving the eastern half of road, where the break occurred, as soon as next Friday.
