Concord Fault

[4] Currently, it is considered to be under a high stress level and therefore has a higher chance of a major earthquake happening.

The last large earthquake linked to this fault occurred over 400 years ago.

[1] According to USGS seismologists it is "the most urban fault" in the East Bay, with potential for a larger event than the 2014 South Napa earthquake.

One particular pumping station, if hit by a quake, would particularly damage transmission of fuel.

A major earthquake there could also cause flooding, which would impact drinking quality, and a loss of electricity.