For 30 years, Pacific Gas and Electric Company knew a natural gas pipeline in Marin County was made of a plastic "known to be at high risk of failure," according to the Marin Independent Journal.
The utility is finally at work removing the pipe -- which, in different locations, has resulted in two explosions -- but the company is replacing only 1,800 feet of the 51 mile-long pipe, the newspaper reported.
The pipe is made of Aldyl-A, a product made by company DuPont, the newspaper reported. DuPont told PG&E in 1982 that pipes made of Aldyl-A prior to 1973 are "prone to cracking," according to a former DuPont chemist.
Pipes that are pressed by soil, rocks, or other "hard materials" can fail in five years, the newspaper reported. All of the Marin County pipe was made before 1973, a PG&E spokeswoman said.
Other Aldyl-A pipes in Cupertino and Roseville have exploded within the past year.