The environmental legacy of uranium mining and milling in New Mexico
— Bruce Thomson


Between 1951 and 1989, the Grants mining district of northwestern New Mexico produced more uranium than any other district in the United States. Almost 250 mines were located in New Mexico, consisting of both open pit and underground mines. Open pit mines, especially the large Jackpile–Paguate Mine on the eastern flank of Mt. Taylor, left a large area of open pits and exposed strata that remains largely unremediated. The Jackpile–Paguate Mine is now a Superfund site. Underground mines had a large impact on regional aquifers, but groundwater levels have largely recovered after closure. Eight mills were built to process uranium ore at one time or another in the state using either the acid leach (seven mills) or alkaline leach process. The Bokum Mill was built but never operated. Tailings were disposed as a slurry in unlined tailings piles. Tailings wastewater was of very poor quality characterized by either low pH (acid leach mills) or high pH (alkaline leach mill), high total dissolved solids, and high concentrations of metals and radionuclides. Most mills were located in remote locations and present little threat to health or the environment, but the Homestake Mill near Milan, NM was declared a Superfund site in 1983 and remediation is continuing. Though no mining or milling has occurred for over 20 years, it is important to understand the legacy of uranium production to develop effective remediation strategies and minimize risks to health and the environment if production resumes in the future.

Full-text (737 KB PDF)

Recommended Citation:

  1. Thomson, Bruce, 2021, The environmental legacy of uranium mining and milling in New Mexico, in: New Mexico Geological Society, 71st Annual Fall Field Conference, September 2021, Geology of Mount Taylor, Frey, Bonnie A.; Kelley, Shari A.; Zeigler, Kate E.; McLemore, Virginia T.; Goff, Fraser; Ulmer-Scholle, Dana S., New Mexico Geological Society, Guidebook, pp. 195-202.

[see guidebook]