Environmentalists filed a lawsuit on Monday to prevent the construction of a new potash mine that they say would devastate a lake ecosystem in the drought-stricken western Utah desert. The complaint against the Bureau of Land Management is the latest development in the battle over potash in Utah, which holds some of the United States' largest deposits of the mineral used by farmers to fertilize crops worldwide. Potash, or potassium sulfate, is currently mined in regions including Carlsbad, New Mexico and at Utah's Bonneville Salt Flats, where the Bureau of Land Management also oversees a private company's potash mining operations.