Stand Up for Clean Water at Public Hearing on Proposed Chino North Lampbright Stockpile


Open House & Public Hearing on Proposed Chino Mine North Lampbright Waste Rock Stockpile 

Show your support for clean water by attending the Mining and Minerals Division public hearing on Freeport-McMoRan’s proposal for a new waste rock stockpile to be constructed northeast of the Kneeling Nun. The North Lampbright Waste Rock Stockpile has the potential to contaminate Grant County’s groundwater. Because the New Mexico Mining Act requires use of best management practices in the operation and clean up of mines, the Mining and Minerals Division should require that Chino follow industry best practice and install a liner system to prevent groundwater contamination from the waste rock stockpile.

Attend the Mining and Minerals Division Public Hearing and say “No” to Freeport-McMoRan’s use of the public’s groundwater supply as a dumping ground for its mine waste. 

WHAT: Public Hearing on Chino Mine North Lampbright Waste Rock Stockpile

WHEN: Thursday, October 27 at 5:30 pm

WHERE: Grant County Commission Meeting Room, 1400 Highway 180 East, Silver City, NM.

Prior to the hearing at 4:30 pm, Freeport-McMoRan will hold an Open House on the proposal.


According to Chino’s application, the proposed North Lampbright Waste Rock Stockpile will be constructed contiguous to Chino’s existing Main Lampbright Leach Stockpile, located to the northeast of the Kneeling Nun. The footprint of the new stockpile will cover approximately 187 acres, with 101 acres in new disturbances.

Stockpile capacity will be about 84 million tons of mine waste rock.  This waste rock is acid generating and may cause toxic metals to leach from the pile into groundwater, potentially causing exceedances of groundwater quality standards. Because the waste rock stockpile will be located outside of the Open Pit Surface Drainage Area, groundwater quality standards are applicable to groundwater under the stockpile. However, Chino is not proposing to install a liner under the waste rock stockpile to serve as a barrier to prevent contaminants from flowing into groundwater. 

Given its potential to generate acid rock drainage, the North Lampbright Waste Rock Stockpile will be a permanent source of groundwater contamination. It is highly uncertain that Chino’s containment system will remain in place to treat contaminated groundwater for as long as it exists, likely for hundreds of years.   Therefore it is critical that best management practices, such as use of liners, are utilized to prevent pollution from leaving the stockpile and migrating into groundwater.

Points you could make at the MMD hearing:

  • Groundwater protection is imperative in an arid state such as New Mexico in which  9 out of 10 residents rely on groundwater for drinking water.
  • Enforce the NM Mining Act and require the Chino Mine to use best management practices at the new North Lampbright Stockpile to prevent groundwater contamination - According to the NM Mining Act, “the mining operation and the reclamation plan shall be designed and operated using the most appropriate technology and the best management practices” (NMAC A).
  • Liner systems reflect current engineering design best practices and should be required at the new North Lampbright Waste Rock Stockpile – The International Network for Acid Prevention’s (INAP) Global Acid Rock Drainage (GARD) Guide “is intended as a state-of-the-art summary of the best practices and technology to assist mine operators and regulators to address issues related to sulphide mineral oxidation.” Freeport-McMoRan Inc. is a member of INAP that developed the GARD Guide.  According to the guide,engineered barriers are low-permeability materials, ranging from synthetic to geosynthetic to natural, that can be utilized “as a barrier for contaminant flow from the overlying waste into the receiving environment.” Why is Freeport not following this guidance on best practices for controlling acid rock drainage? MMD should require a liner system at the North Lampbright Waste Rock Stockpile as it reflects industry best practice.

If you can’t attend tomorrow’s hearing, public comments can also be submitted to the MMD Director:

Fernando Martinez, Director

Mining and Minerals Division

NM Energy, Minerals and Natural Resources Department

1220 South St. Francis Drive

Santa Fe, NM 87505


A copy of Chino’s application is available at the Bayard Public Library and on line at:


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