Cargill Salt Mine

     Cargill, Incorporated is an American privately held global corporation based in Minnetonka, Minnesota, and incorporated in Wilmington, Delaware. Founded in 1865, it is the largest privately held corporation in the United States in terms of revenue. 
     Some of Cargill's major businesses are trading, purchasing and distributing grain and other agricultural commodities, such as palm oil; trading in energy, steel and transport; the raising of livestock and production of feed; and producing food ingredients such as starch and glucose syrup, vegetable oils and fats for application in processed foods and industrial use. 
     Cargill also has a large financial services arm, which manages financial risks in the commodity markets for the company. 

     What most people living in Cleveland, Ohio don’t know is that there’s a whole other world lurking beneath Whiskey Island, a peninsula at the mouth of the Cuyahoga River in Cleveland. Whiskey Island was the first piece of solid land amid the swamps lining the river one-quarter mile down the Cuyahoga when Moses Cleaveland visited the area in 1796. Lorenzo Carter built his family farm on Whiskey Island, which got its name after a distillery was built on the site in the 1830s. 

      Lake Erie is the shallowest Great Lakes and near the shores of Cleveland, it's only about 65 ft. deep and the mine goes down 1,800 feet below Lake Erie. The Cargill Salt Mine covers about 12 square miles as it stretches out under the lake. It’s the place where the rock salt that covers Ohio’s streets in the wintertime comes from. 
     During an average winter, the mine will produce approximately 4 million tons of rock salt. Once the salt is drilled, blasted and scooped, it's sent to the surface for processing via a system of conveyor belts and elevators. 
     In the mine, giant pillars of salt are intentionally left to support the layers of rock on top of the salt. Within the pillars, you can see layers of salt and other types of rock. 
     The elevator, known as the skip, takes about three minutes to descend and at the bottom, a giant metal door swings open, and you enter a world where the walls, ceiling and floor are made of salt. 
     It’s dirty at the mine’s entrance, where the rock has absorbed diesel fumes and dust for more than 60 years. But, pristine white salt with glimmering flecks can be seen at the far reaches which stretch for three miles out and five miles wide under Lake Erie an Crews ride in a truck to drive out to the far reaches of the mine each day, a 20 minute trip and every day the mine gets a little bigger as crews stick explosives in the walls and blast the salt loose. 
     Workers drill holes in the salt walls, then insert ammonium nitrate fuel oil. They blast the wall, then use a modified front-end loader to deposit the chunks of salt in a crusher machine, which channels it onto a conveyor belt. The belt leads to the mill, where the salt is refined, before being hoisted out on another elevator A giant machine claws at the ceiling and walls, to get all the excess salt. 
     The air feels dusty and gritty on your skin and you can taste the salt on your lips. The only light comes from lamps on the miners’ hardhats and the headlights on vehicles. The air in the mine is dry, though it may get humid in the summer and temperature is steady year-round, at about 68 degrees. A single fan pushes fresh air through the mine and channels the dusty air, polluted with diesel fumes, back up to the surface. The fan is so strong that near the entrance, wind blows your hair around. 
     The mine can produce 4 million tons of rock salt each year, but because of mild winters, the last two years the mine has produced about 75 percent of an average year. Every year, engineers revise a 25-year plan, deciding where to drill next. The mine could conceivably go on at least to the Canadian border, but they ay it has at least 50 years more or until trucking miners out to and salt back from the far reaches of the mine becomes too expensive. 
     Actually, the mine could be anywhere in the Great Eastern Salt Basin, under a huge area stretching from Michigan to New York, through Ontario. Under Lake Erie, though, Cargill has to lease land from only one owner, the state of Ohio, not thousands and thousands of owners. 
     The mine does leak! But only in two spots: the skip (elevator) and in one room where the ceiling converged and caused the mine to close temporarily four years ago. But, the water isn’t coming from the lake; it seeps in from the layers of rock in between Lake Erie and the mine. 
     From Cleveland, ships carry 1.6 million tons of salt to ports around the Great Lakes, including Duluth, Chicago, Milwaukee and Canada. Salt is also transported by train as far as Massachusetts and by truck to southern Ohio. About 30-50 percent of the total salt is extracted, with walls and columns of salt left to support the structure. There are no other supports, aside from metal studs drilled into some portions of the roof. 
     Everyone underground must wear what’s called a self rescuer in a metal container on a belt. The device fits over your mouth and changes carbon monoxide into carbon dioxide. In an emergency, miners would exchange their self-resuers for larger self-contained self-rescue devices, kept in boxes throughout the mine. Those provide oxygen for an hour. There are green reflectors lining the tunnels, showing the way out. And the mine has two safe rooms stocked with food, water and oxygen to last three days. 
     Even though it’s about 98 percent sodium chloride, it’s really not edible. Table salt comes from other sources.