At a November 10 open house, PG&E acknowledged that there had been 42 gas leaks in its distribution lines since 2006 in the Stonegate subdivision in west Davis.
At a meeting at the Stonegate Country Club, 75 concerned residents were told about problems with the Aldyl-A plastic distribution lines maintained by PG&E throughout the subdivision.
PG&E attempted to downplay the significance, citing that the leaks that are left are the tiny Level 3 leaks. PG&E told residents that there are only smaller distribution lines in Davis. These distribution lines are mostly under sidewalks.
The nearest transmission line, which is eight inches in diameter, is about three miles to the east of Stonegate and parallels I-80.
According to PG&E, the Stonegate community has 4.7 miles of gas distribution pipe, mostly Aldyl-A made by DuPont. Of that amount, 5.1% is pre-1973 Aldyl-A pipe, which is of special concern. But according to a 1998 National Transportation Safety Board report, even plastic pipe made through the early 1980s is susceptible to brittle-like cracking and premature failures under certain circumstances.
“PG&E had information that there were a substantial number of gas leaks clustered in west Davis, yet they kept this information secret from city officials and residents, until it was released yesterday. I find it unconscionable that PG&E did not act to notify Davis residents and develop a plan to replace the defective pipe,” stated David Johnson, a Stonegate homeowner who has experienced two gas leaks.
On October 27, PG&E representatives agreed to replace the plastic distribution lines in the Stonegate subdivision, but no timetable has been provided.
Even though PG&E has known about this problem for years, the company’s action plan for Stonegate is still under development and being prioritized, according to PG&E officials at the open house.
In a one block area on Marina Circle in Stonegate, there have been six gas leaks in the last 18 months. On October 31, PG&E found and repaired four additional leaks in the Stonegate area. PG&E is now conducting twice-monthly inspections of gas lines in the area.
The Vanguard had spoken to Fire Chief Bill Weisgerber about the danger presented by the leaks.
“Anytime there’s a gas leak and there’s a source of ignition, you can have a problem,” the Chief told the Vanguard last week. “I know everyone is thinking the San Bruno transmission line, but these are actually the smaller, what they call distribution lines, they’re probably two-three inches in diameter.”
“Even those do present a problem if they start to leak,” the Chief said. “But typically it’s a less severe risk -you aren’t as likely to see an explosion.”
Chief Weisgerber noted that they will be replacing the older lines first and then incorporating into the larger plan for the state, where they will be replacing more than 1200 miles of old and outdated pipeline.
Chief Bill Weisgerber said that, while he does not have any statistics, he does believe the problem right now is clustered in the Stonegate area.
“I think they are experiencing a high frequency in the Stonegate area,” he said. However, there are about 1200 miles of that age and composition of pipe called Aldyl A.
The San Francisco Chronicle reported recently that “Aldyl A gas pipes have been linked to one explosion and one fire in Northern California in the past 8 weeks.”
On August 31, a condominium in Cupertino was destroyed by a gas leak from an Aldyl A pipe leak.
On September 27, an Aldyl A pipe ruptured in Roseville, sparking a fire at a commercial intersection that burned for seven hours and forced a 12-hour shutdown of the street.
One point that should be made clear, these are very small pipes, in general less than two inches in diameter, a far cry from the 30-inch pipeline that ignited and exploded in San Bruno.
The gas lines in question in far west Davis are located under streets, sidewalks and landscaped areas, not inside houses which typically have smaller metal gas pipes.
According to PG&E, the primary gas distribution lines in Stonegate are 2″ in diameter, which feed into 1/2″ pipes leading to the gas meter on each property. Distribution lines are not similar to the 32″ steel gas transmission line that exploded in San Bruno. The San Bruno transmission pipe also had an increased amount of gas pressure, much more than the distribution lines in west Davis.
A second informational open house hosted by PG&E is scheduled at the Stonegate Country Club in Davis on November 16, 5:30-7:30 p.m., to brief residents.
—David M. Greenwald reporting
Doesn’t give Davisites very much comfort does it? Thanks to Fire Chief Weisgerber for at least speaking to the issue of the danger of the leaks…
Does anyone know when the Stonegate neighborhood was built? My neighborhood was build in the mid to late 60s and I’m going to guess that there are a lot of older neighborhoods in the same boat … we just haven’t exprienced any major leaks yet. I’ve been in the same house for 32 years and I don’t remember PG&E ever coming by to check on anything.