Hearing about the San Bruno explosion brought back memories of another PG&E explosion that killed two, injured three others, and destroyed an apartment building in Santa Rosa.  In fact, the Wall Street Journal even mentioned that explosion in its article discussing the San Bruno blaze.

I spent 4 years prosecuting the case against PG&E on behalf of the families of those killed. Some of the lessons I learned from that case seem applicable here:

  • Gas leaking from the street will follow the path of least resistance. The path is typically through the airspace that exists around the pipes that lead into or under the nearby houses.
  • Natural gas has no odor. PG&E adds to the gas an odorant (called mercaptan) before distributing it. The sole purpose of the odorant is to help in detection of leaks.
  • The odorant is stripped from the gas when the gas passes through or along dirt. That means the odorant is effective of alerting people of a leak from an appliance such as a stove, but is much less effective at alerting people of a leak from the street.

If even one person reports to PG&E the smell of gas, or rotten eggs, or a smell like rotten food — however faint — PG&E must chase it down.  If the smell cannot be traced to an appliance, it’s potentially big trouble. A faint smell of gas can mean either a very small leak from an appliance or a huge leak that has passed through soil, been stripped of its odorant, and is permeating the neighborhood homes. 

In any case, locating and controlling leaks is PG&E’s responsibility.