"Drilling Down," a series by The New York Times, explores the the risks of natural-gas drilling, along with efforts to regulate the industry. "The relatively new drilling method — known as high-volume horizontal hydraulic fracturing, or hydrofracking — carries significant environmental risks." For each well the process can create over a million gallons of wastewater ladden with toxins, and EPA documents reviewed by The Times indicate that the risks are greater than previously thought. Many companies have been recycling the wastewater created by the hydrofracking process, but these efforts do not eliminate the health and environmental risks associated with this type of natural-gas drilling. The Times is posting the significant documents used in the reporting of these stories.