The spill occurred at approximately 8:30 PM on May 4, 2010. Fort Knox Gold Mine notified ADEC via the Alaska State Troopers at approximately 9:49 PM on May 4, 2010.
The process water spill occurred within the ore processing facility. Fort Knox estimates the amount spilled at 305,300 gallons. Approximately 270,000 to 275,000 gallons remained within the building, while the remaining 30,000 to 35,000 gallons spilled onto the gravel roadway and parking area.