Complex sentence: Large coal power plants use a phenomenal amount of coal each day, enough to fill a hundred train coal cars carrying 100 tons each, so the water used to transport the coal is significant, particularly in arid regions, like the Southwestern United States.
Split into simpler sentences: Large coal power plants use a phenomenal amount of coal each day; enough to fill a hundred train coal cars carrying 100 tons each. Water used to transport the coal is likewise significant, particularly in arid regions like the Southwestern United States.