Pit Dewatering

 

The Kings Mountain Mine’s open pit began accumulating rainwater over the last several decades since prior mining operations ceased in the 1990s. To continue to conduct additional prefeasibility studies and ultimately resume mining operations, the accumulated water must be removed. We expect to dewater the pit over an 18-month period. Albemarle is treating and discharging water under the limits of a state-issued National Pollution Discharge Elimination System (NPDES) permit which is required to protect downstream water resources.

Protecting the Wildlife

With concern for the pit lake inhabitants, wildlife biologists have completed studies of the aquatic species to ensure that no threatened or endangered species live in or around the pit. The only aquatic species found in the pit is the common bluegill, which is not threatened or endangered. Biologists anticipate that birds and mammals will adjust and access other water bodies on and off-site.

The Dewatering Process

Treating the pit’s water requires a multi-step process to ensure the discharged water meets regulatory standards. To begin the process, water is conveyed by electrical pumps from the pit to a water treatment plant, where it is filtered to remove sediments and treated to remove any potential contaminants. Lastly, the water is treated by ultrafiltration to ensure clarity and transferred to a finished water tank before being pumped to discharge into Kings Creek.

Water quality is continuously monitored with in-process sensors for pH, clarity, dissolved oxygen, and temperature. We expect to conduct weekly to quarterly sampling along various points of the dewatering system from the treatment plant to Kings Creek.

Albemarle is discharging the water at a rate that is compliant with standards to preserve the integrity of Kings Creek and the river basin.

Managing Odors

There may be an occasional odor as the water level drops in the pit during dewatering and decomposed materials at the bottom of the pit are exposed. The water treatment process was specifically selected for pit dewatering to mitigate odor during the process due to low dissolved oxygen at depth in the pit lake. We anticipate there will be little to no discernible smell beyond the pit during the process.

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