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Berkeley Pit Monitoring

Water Monitoring is an integral component of ensuring the protectiveness of the Berkeley Pit remedy. The main source of water entering the pit is groundwater from the alluvial and bedrock aquifers.  Monitoring includes collecting information from a system 38 alluvial aquifer wells and 22 bedrock aquifer sites (wells and mine shafts).  Within the alluvial aquifer, 21 of the 38 wells are within the active mine area.  The bedrock aquifer monitoring sites include 12 wells within the active mine area, 4 wells outside the active mine area, and 6 mine shafts.  The water levels at these sites are monitored monthly.

The 2002 Consent Decree (CD) established the maximum elevation water in the East Camp bedrock system will be allowed to reach and is based upon the lowest point at which water drains out of the valley to the west.  The terms of the CD state the water level in the bedrock system cannot exceed the Protective Water Level (PWL) of 5,410 feet elevation. There are 14 compliance points within the East Camp system where groundwater must remain below this maximum elevation.  The compliance points include mine shafts (Anselmo, Steward, Pilot of Butte, Granite Mountain, Lexington, and Kelley), the Continental Pit or its monitoring well at the Sarsfield Shaft, and bedrock wells A, C, D-1, D-2, G, J, and Belmont well #2. 

Water Monitoring Reports

Download the latest water monitoring Annual Report from the Montana Bureau of Mines and Geology titled “Butte Mine Flooding Operable Unit Water-Level Monitoring and Water-Quality Sampling 2016 Consent Decree Update Butte, Montana 1982–2016.” below:

Annual Report

For past monitoring reports please email us at info@pitwatch.org.