Boiling earth Union Pacific railroad tracks, SR-111, threatened by ‘mud pot’
NILAND — The Imperial County Office of Emergency Services is keeping a wary eye on a transitory “mud-pot” geyser located about 5 miles northwest of Niland that is threatening a nearby rail line and State Route 111.
This mud-pot geyser is one of about 33 mud pots and so-called “mud volcanoes” located in an area immediately east of the southeastern-most portion of the Salton Sea that sits atop the terminus area of the San Andreas Fault.
Mud pots and mud volcanoes are geothermal features produced when water or gas is forced upward through soil and sediments, according to Seismological Society of America. At the Salton Sea, a shallow magma body causes carbon dioxide to form in the soil, according to the U.S. Geological Survey’s Earthquake Science Center in Pasadena.
Mud pots typically are depressions or enclosed basins containing gas seeps, bubbling water or viscous mud. Hydrogen sulfide gas is usually present, giving mud pots a characteristic odor of rotten eggs.
Mud volcanoes are elevated conical structures composed of accumulations of viscous mud extruded from a central vent. They range from finger-sized to several kilometers across, though the largest in the Salton Sea area are about six-feet-tall.
Bubbling mud pots can be found in such locations as Imperial County, Cerro Prieto in Mexicali and Yellowstone National Park.
The mud pot threatening the transportation infrastructure has been active and moving since 1953, according to Fire Chief Alfredo Estrada, Jr., OES coordinator, and now lies about 160 feet east of existing dual Union Pacific Railroad tracks and 210 feet east of SR-111, which may both be in danger of being damaged by the natural phenomenon.
To mitigate damage to the tracks at the current distance, sheet piles have been placed between the geyser and the tracks. The sheet piles may be effective at the current distance, but this tactic may not prevent damage to the tracks should the geyser continue moving closer, said Estrada in a June 22 letter to the board of supervisors.
Local state of emergency extended
During their regular meeting Tuesday morning, the Imperial County Board of Directors voted 4 to 0 — Michael W. Kelley, District 3 supervisor, was absent — to extend a local state of emergency to address the threat to both the railroad and the highway.
The extension allows for expedited emergency repair work to continue around the mud-pot geyser, Estrada said.
A local state of emergency was declared originally by the board during their June 26 meeting. Such a declaration can be made when there is an existence, or threatened existence, of a public calamity — in this case one that threatens major critical infrastructure. The dual rail line is vital to the movement of goods into and out of Imperial County, while SR-111 is one of only two main arteries available for north-south transportation around the Salton Sea.
Union Pacific Railroad and Caltrans officials have expressed interest in coordinating efforts with Imperial County to address the issue.
Mitigation efforts may need to be paid for out of the Imperial County General Fund, but an estimate is not available on how much money may be required. More research in coordination with Union Pacific and Caltrans will be needed before the full scope of necessary mitigation efforts, and the associated costs, are determined, Estrada said.