Pit Lake Modeling, Mineral County, Nevada

Humboldt Pit Lake

In 2003, groundwater began to fill the former pit workings at what is now the Humboldt Pit Lake in Mineral County, Nevada. Since then, Humboldt Pit Lake has been monitored continually for water quality. In order to comply with permit requirements for the mine, Sovereign was contracted to develop a pit lake model to explain current observed water quality in the pit and to project expected changes to water quality over the near term.

The pit lake water is near neutral and well buffered due to carbonate mineralization in the area despite the occurrence of pyrites in the volcanic derived overburden. Since pH is near neutral, metal concentrations are below detectable quantities, as are metal(oids) such as arsenic and selenium. Sovereign's forward models suggest water quality will remain quite good for the near term.