Coal companies are required to restore land used for coal mining to the shape it was in before they started digging it up. It’s federal law — mandating that what was once pastureland, for instance, could again be suitable for grazing livestock after being mined. But as the coal industry struggles to stay afloat amid cutthroat competition from wind and solar power as well as natural gas, mining companies are finding new ways to cut corners. In Texas, that has involved lobbying the state to restore land to lower standards. The end result: Thousands of potentially contaminated acres across the state could be saturated with dangerous chemicals. In this three-part series, Grist and The Texas Tribune examine the controversial legacy that coal mining companies are leaving behind in the Lone Star State — and how Texas is helping them save millions of dollars in the process.