Ann: Positive Metallurgical Test Results - Halleck Creek Project, page-23

And then the Nevada Division of Environmental Protection adds,

Spills happen, even at well managed operations. Equipment failures and the release of hydraulic oil and diesel fuel can occur. Some of the largest mining trucks in the world operate in Nevada’s mines. A single hydraulic line failure could release 180 gallons or more of oil onto a haul road.The operators are required to perform three steps immediately upon a release: 1) Contain the spill and stop its spread. This may include digging a depression or utilizing absorption pads; 2) Clean up the contamination by excavating the affected soil; 3) Take confirmatory samples of the ground area affected by the release to ensure all of the contamination was cleaned up. This same procedure is undertaken if there is a release of chemicals from a process solution spill. Additionally, the operator is required to call into the Division’s Spill Hotline to report releases greater than 500 gallons for process solution or 100 gallons for petroleum. All spills greater than 25 gallons, or 3 cubic yards of soil, must be reported by the operator in the quarterly report. Regardless of size, all spills must be cleaned up as soon as they are discovered.