...They worked even as stinking sulfuric steam rose from storm drains from the hot spring that was disturbed in the quake, and continues to pump an estimated 500 gallons of hot mud a minute through a growing hole in the City Hall & Library parking lot.
Paso Robles, California - Dec. 22, 2003
Mag. 6.5 Earthquake causes hot sulfuric mud to flow at 500 gallons per min.
I have yet to run across 111 degree sulfuric mud without a Volcano system in place. Is there an undiscovered volcano around Paso Robles? Long Valley Caldra is the closest I can find.