CLEVELAND-- A potentially dangerous situation has shut down production at the Cargill Salt Mine located on and under Lake Erie.
The more than 50-year-old mine rests 1800 feet below the waters of Lake Erie and 4 miles from the shore.
As part of the Great Eastern Salt Basin, the mine is an engineering marvel and the only mine in the United States that’s located in a city, not far from downtown Cleveland.
Thousands of tons of salt is extracted from the 300 million year old salt basin and then brought to the surface on conveyor belts. The majority of the rock salt is then used as a deicing agent for roads across Ohio and many other Midwest states.
But operations suddenly shut down Monday, and workers were sent home after a sensor in a “mined” tunnel detected a geological shift.
Mark Klein, Cargill Director of Communications said, “We just thought it was the prudent thing to do, to check out what this is about.”
According to Mr. Klein, about 100 miners who work three different shifts under the lake were told to stay home this week with pay.
He said the movement is small and would be undetectable by the human eye.
But in a mine, even 1/100 of an inch shift is taken seriously.
The mine is closed so that they can get equipment down to the area, ”to see what the movement’s all about.”
Seismic monitoring devices, video cameras and fiber optic cables are being installed so that the mine can be closely surveyed from the surface.
They need to ensure that the earth isn’t giving way to the crushing power of Lake Erie.
Experts are also being consulted.
“We’re drawing on mining engineer consultants as well as geology consultants and we’ll get to the answers,” said Klein.
This isn’t the first time a geological shift has taken place at the mine. In the mine's 50 + year history a shift has occurred at least a couple of times.
However, given the nature of their business, Cargill is not taking any chances.
“We’re not looking at anything catastrophic, but then again, it’s better to be prudent and not have any mining going on below the surface,” said Klein.
The Cargill mine has enough salt to remain open for 100 years, but the earthen tunnels must be secure.
There are possible fixes, but it's too early to say what might happen next.
If the mine is closed for more than a couple of weeks it could affect salt prices this winter, but at this point the company’s main concern is safety.