PG&E crews began carving out sections of the street to gain access to the old plastic pipeline, known as Aldyl-A.
"The lines you see here along the road and outside the homes, those are the main lines and from the main line and from there branching out to the individual service lines that go directly to the meter," PG&E spokesperson Brian Swanson said.
Twelve-thousand feet of pipeline will be replaced after a gas leak caused an explosion that rocked a Cupertino neighborhood on August 31. In September another Aldyl-A line installed in 1981 exploded in Roseville near Sacramento.
The type of plastic used in Cupertino has failed in the past. The maker, Dupont, had warned Aldyl-A pipe made prior to 1973 can crack.
Assm. Jerry Hill, D-San Mateo, says there were other warnings.
"The National Transportation Safety Board in 1998 came out with a recommendation that the pipes should be checked, monitored and replaced; here again nobody did anything about it," Hill said.
PG&&E claims it has. Still, the utility company says replacing all plastic pre-1973 Aldyl-A pipes was not priority until now.
"That program has been focused on the old steel service lines that don't do well during earthquakes, now that that is wrapping up we are now actively starting to replace pre-1973 Aldyl-A in our system," Swanson said.
PG&E will replace 1,200 miles of the plastic pipeline system wide, which will take at least four years.
In the meantime, many living up and down the Peninsula want to know where they are located.
"There are communities that have been built up and developed around 1970, late 60s that would probably have plastic pipes the Aldyl-A that is pre 1973 is the one that really has the serious problems," Hill said.
PG&E promises to have that information in the next three to six months.
"We are finalizing the process now of identifying where exactly all this pipes exists and putting it into a central electronic data base," Swanson said.
Hill will now introduce legislation demanding that all safety recommendation made by the National Transportation Safety Board be adopted by all utility companies.