Worrisome maze of underground gas lines

<p>Mark Powell is nervous every time one of his crews digs down beneath Santa Rosa to where miles of pipes filled with high-pressured natural gas lurk.</p><p>“Every time my crew goes out and digs, it's scary, because you kind of know where the lines are — but do you really?” said Powell, deputy director of local operations in the city's Public Works Department.</p><p>Powell's crews have electronic maps and tools to help as guides. But a slight miscalculation, due to equipment malfunction or operator error, could result in the kind of as-yet-unexplained catastrophe that consumed a San Bruno neighborhood Thursday. </p><p>“I watched that whole thing in horror,” he said.</p><p>Such tragedies, while rare, bring home the risks of working on or near gas lines, about 325,000 miles of which snake across the country. </p><p>That's roughly 87,000 miles longer than the distance from the Earth to the moon.</p><p>PG&E owns most of the gas lines in Santa Rosa and Sonoma County.</p><p>Attempts Friday to question PG&E about the extent, age and maintenance of its pipeline network in Sonoma County were unsuccessful. A spokeswoman for the company said she could not comment about gas lines in the county without approval from the National Transportation Safety Board, which is investigating the deadly inferno in San Bruno.</p><p>Those investigators are trying to determine what caused a 30-inch gas pipe owned by PG&E to rupture, fueling the massive fireball that destroyed dozens of homes and killed at least four people.</p><p>It's not particularly alarmist to think that such a tragedy could happen here, or anywhere that gas lines exist.</p><p>In December 1991, an explosion fueled by a ruptured natural gas line destroyed four apartments on Humboldt Street in Santa Rosa's Junior College neighborhood, killing a 43-year-old woman and her 2-year-old granddaughter.</p><p>Investigators traced the leak to a gas line where construction crews had been working to replace water and sewer lines.</p><p>Powell, who oversees those systems for the city, said he has a pretty good idea where those lines run.</p><p>But he said he doesn't know where most of the city's natural gas lines are because PG&E doesn't share that information except when it's needed for a specific project.</p><p>Powell said that policy is an attempt to limit the number of people who have access to that information.</p><p>“Because of the nature of their product, it could be dangerous if they (the location of the gas lines) got into the wrong hands,” Powell said.</p><p>He said it's therefore incumbent on his crews to proceed with caution before starting to dig.</p><p>“There's a maze of stuff under you — you've got cable, telephone, water, sewer, gas and who knows what else,” he said. “People have put in private lines, sometimes on privately-owned streets, and nobody keeps a record of it. That's scary for our crews.”</p><p>He also is concerned about the natural wear of a pipe that can lead to a rupture without any provocation.</p><p>The gas line that broke in San Bruno was reportedly 50 years old, which is considered the shelf life for a water or sewer pipe, Powell said. Gas lines are made from different materials than those lines, though.</p><p>Powell said that by law. crews must dig by hand within two feet of a marked utility until they receive approval to use power equipment.</p><p>He said the most important safety precaution for anyone who wants to dig on their property is to dial 811 first and report the location to the underground service alert system.</p><p>That will result in a crew coming out to determine where underground lines are so that the work can be performed safely.</p><p>“Even if you're just putting in a mailbox on your front lawn, you always call,” Powell said.</p><p>You can reach Staff Writer Derek Moore at 521-5336 or derek.moore@pressdemocrat.com</p>