Pennsylvania’s energy history is rich with the quantities of fossil fuels that it has produced, but is also rife with the environmental legacies of coal mining and, more recently, hydrofracturing. Water that finds its way into abandoned coal mines dotted throughout the Commonwealth resurfaces as acid mine drainage (AMD), while freshwater used to fracture or “frack” oil and natural gas deposits reemerges as “produced” water contaminated with salts, metals, and radioactive material.