Reviewing History – The Walnut Creek Explosion


In November of 2004, the high-pressure fuel pipeline breach at Walnut Creek was one of the worst in California’s history. Many lives were changed forever, subsequently this event would go on to highlight the importance of managing encroachments and working with engineering and design firms in the early stages of projects. Doing so would have safely identified the error that caused the November 9, 2004 tragedy.

An excavator trenching for a water main owned by the East Bay Municipal Utilities District near downtown Walnut Creek punctured a 10-inch petroleum line that was assumed to be a few feet away. The resulting explosion cost five workers their lives as well as the destruction of a nearby home and even forced the evacuation of a school.

The follow-up investigation led to the discovery of a bend in the pipeline incorrectly marked due to the presence of an oak tree. No aboveground signs indicated a cause for concern or that the pipe did not run straight because the oak tree was removed in 2000. This accident is still remembered as a tragic example of the importance of communication and proper map detailing between engineering firms and pipeline companies. Companies now implement damage prevention programs and have technicians who are charged with responding to call notifications to make sure that an event like this never occurs again.


Contributed by Harrison Haley, Marketing Associate