By Harvey I. Barkin
SAN JOSE – Pacific Gas and Electric (PG&E) Company recently invited day workers to inform them of the dangers of natural gas and make them aware of their look-before-you-leap phone number at the ConXion to Community Day Worker Center.
In this case, 811 is the call-before-you-dig number.
Retired PG&E gas service expert and Filipino-American Rudy Herras demonstrated to a group of mostly Latino contractors about doing due diligence before digging.
“It’s just three digits. But you should call it in before you find yourself in a bad situation when you have to call 911. We want you to dig and work but go back home safe at the end of the day.”
The more than 42-year PG&E veteran who has worked through the 1989 earthquake and the 1991 fires said, “It’s also a one-stop shop. Two days before you dig, call 811. They will notify all utilities: the water, gas and electric companies.”
Herras didn’t deliver a Powerpoint presentation but demonstrated his point with an almost to-scale model community complete with houses, trees and electric poles. It simulated the hissing of a punctured gas line and erupted in flames on cue.
Herras explained that most consumers take for granted that natural gas is commonly used in households but it can cause harm and, if not handled properly, cause fire. Natural gas is delivered by PG&E through steel, plastic and a few copper pipes. The interaction between copper and gas deteriorates the pipes. PG&E has identified most of the services needed in the system.
Responding to the 811 call, the PG&E operators will locate and identify the underground lines, and mark them with specific colors. Yellow means gas, oil, steam or chemical flowing through the line. Red means electric power line. Orange means cable and communication. Green is for storm drain. Blue is potable water. Purple is for irrigation. White means proposed for excavation and magenta for survey marking.
According to Herras, gas is distributed in a city like San Jose through about 42,000 miles of PVC pipes ranging from ½ to 10 inches wide. Another system of transmission lines sends the gas through higher pressures from 60 to 900 pounds through pipes ranging in width from 10 to 48 inches. This, he said explains full well the potential harm of digging unknowingly around pipes, guessing which one’s for gas and which one’s for electric power. “If you don’t call before you dig . . .” he hung back ominously, addressing those about to dig with shovel, jack hammer and back hoe excavator.
“You’re not Superman and you don’t have x-ray vision. But you can call 811.”
Herras drew attention to the model. “Let’s say the boss said, ‘I want a Japanese maple planted in the front yard.’ There’s a gas meter but you can’t (identify) the gas line because there’s no yellow marking. You start digging and you get an odor.” He releases a valve and a hissing signifies leaking gas.
“You just hit the gas line.” Nowadays, methane is added so that the offensive smell is there if you missed the hissing sound.
“This happens and you don’t know what to do. Through all this the gas gets into the house. Now you have a potential fire and explosion. The gas reaches the water heater pilot and sets it off. Your $500 job has now become more expensive.” He fiddles with another button and simulated flames lick the sides of the house.
He also warned about small construction jobs to fix the lateral sewer line. With the pipes not marked, there’s also danger. “All of a sudden, there’s (released valve makes hissing sound), the sewer line is broken and you hit the gas line. Sixty pounds of pressurized gas blows out of the pipe and it needs to escape somewhere. It goes up and goes into the main line if the lateral line is broken. These lines are connected to other houses and (another button and more flames lick the edges of all the houses).”
Herras said if back hoes are left to operate without due diligence they could “open 36-inch pipes like a can opener with 350-pound pressure. It would sound like a jet.” In this situation, he said, the operator should shut off his engine and call 911, too late for 811.
He also said that any time there’s a dig, it’s a good idea to notify the utility companies. He cited a situation when a nick on the pipe resulted in no immediate danger. “But 25 years later, erosion does the job and there’s a leak in the pipe.”
He also told of a farmer who found an old steel 12-inch pipe while grading his land. He did not know about it and called the utility company about the seemingly abandoned pipe. The utility replied that it was an old petroleum line and still active.
Sometimes, some homeowners would put more top soil and concrete or a big tree prevent making access to the gas meter difficult. In some cases, the tree could push out the gas meter, increasing the risk for gas leak. Hillside homes are at greater risk where erosion occurs quicker.
Herras explained that California excavation law says anytime there’s dirt to be moved, you must call 811. If there’s a casualty, the State could prosecute. In most cases the liability still falls on the homeowner.