Combines geochemical research on uranium transport and mineralogy at former Colorado mill sites with regional waste management documents and water policy records to address legacy contamination and remediation planning.
Uranium contamination remediation addresses the long-term legacy of uranium ore processing in the American West, including parts of Colorado where milling, mining, and tailings disposal left radiological and chemical contaminants in soils, sediments, and groundwater. Although the Gunnison Basin is best known for ranching, recreation, and biological research, it sits within a broader regional landscape shaped by uranium and molybdenum mining proposals, including the Homestake Mining Company Pitch Project on the southern flank of the basin Homestake Pitch Project Draft EIS and the Mt. Emmons molybdenum project near Crested Butte, whose water rights have repeatedly been litigated Mt. Emmons Water Rights Decree. Understanding how uranium behaves in the subsurface after mills close is therefore directly relevant to how western Colorado communities evaluate new and legacy extractive proposals.
The science behind remediation focuses on uranium mineralogy — the association of uranium with different solid-phase minerals that controls whether uranium stays put or moves with water. Key concepts include solid-phase uranium, sorption (the binding of dissolved uranium onto mineral or organic surfaces), the vadose zone (the unsaturated soil layer above the water table) and the saturated zone below it, saturation indices that describe whether minerals like gypsum or calcite will dissolve or precipitate, and calcium uranium carbonate complexes and the calcium common ion effect, both of which influence uranium mobility in groundwater. These technical ideas matter because regulatory cleanups that meet surface radiological standards do not necessarily address residual uranium in deeper sediments that can continue to release contamination for decades.
Federal uranium milling expanded during the Cold War, and many sites in Colorado — including the Grand Junction pilot mill studied by the U.S. Department of Energy Office of Legacy Management and the U.S. Geological Survey — were later remediated under federal authorities that emphasized removing tailings and meeting radiological surface standards (Johnson et al., 2021). In the Gunnison Basin, local government engagement with such projects was shaped by environmental review frameworks of the 1970s, including the A-95 Project Notification and Review System that gave counties a formal voice in federally assisted projects Local Government Participation in A-95, and by early county-level review of mining EISs such as the Homestake Pitch Project .
Speed of water flow in streams, affecting nutrient movement and algal composition
The association of uranium with different solid-phase mineral forms that influences uranium mobility between solid and water phases
Radial velocity of particles measured by Doppler radar
Stream discharge measurement using acoustic doppler velocimetry with systematic cross-sectional velocity measurements integrated to calculate total fl...
Mica sheets are placed over thin sections, irradiated in a nuclear reactor, and examined under microscopy to identify areas of elevated uranium concen...
Use of ground control points to associate calibration images and video to real-world distances and provide pixel ground scale distance for each video.
Transmission electron microscopy with energy dispersive X-ray spectroscopy performed under anoxic conditions using vacuum transfer holders to map elem...
Technical report (2019). Covers Boulder County, Orlando, FL. Topics: waste composition, waste generation, waste disposal, recycling. Agencies: Boulder...
Kenneth Watters. Gunnison County Board of County Commissioners. September 6, 1978.
Barnard Dunkelberg & Company, Isbill Associates, Inc. June 2000.
HOUSING MISSION STATEMENT __ GENERAL CONCEPTS GENERAL POLICIES Goal: Gunnison County recognizes that all county residents should have access to safe, ...
District Court, Water Division No. 4, Colorado. September 1, 1999.
U.S. Department of Housing and Urban Development. 1977.
It has also been mentioned that more dust retardant be used on the roads. Last year when this substance was used on the Tincup Road, the procedure res...
Discharge data collected at the East River in the Upper Colorado River Basin for the Lawrence Berkeley National Laboratory's Watershed Function Scient...
A series of field measurements of surface water velocity derived from video and Doppler velocity radar collected by small unoccupied aircraft systems ...
Supplemental Data Files for a submission to Geosciences, "Using Fission-Track Radiography Coupled with Scanning Electron Microscopy for Efficient Iden...
This child item contains Doppler radar velocimetry spectra measurements for each field site where the radars were deployed. Each field site is abbrevi...
This child item contains information about associating the calibration images and video to real-world distances using ground control points for each f...
Regional advocacy and regulatory documents from this period also illustrate how air, water, and land-use law intersected with mining. The Colorado Open Space Council's Legislative Bulletin tracked state air-quality rules that affected mining and milling operations Legislative Bulletin Special Air Issue, while the Colorado Geological Survey weighed in on geologic hazards relevant to mining-adjacent development around Crested Butte CGS Letter Re: Crested Butte Properties. Water-rights decrees concerning the Mt. Emmons mine demonstrate how Colorado water law became a central tool for shaping — and constraining — mining-related contamination risks Mt. Emmons Water Rights Decree.
At former mill sites, the U.S. Department of Energy Office of Legacy Management, working with contractors such as RSI EnTech and partners like the U.S. Geological Survey, leads characterization, monitoring, and remedial design. Recent work at the Grand Junction Office (GJO) site has used fission-track radiography paired with SEM-EDS analysis to identify exactly which mineral phases host residual uranium — including aluminum–silicon gels, gypsum coatings, and organic carbon (Johnson et al., 2021). Column experiments have then shown how different waters (deionized water, site groundwater, and river water) mobilize uranium from vadose- and saturated-zone sediments, demonstrating that river flooding can flush uranium more effectively than rainfall (Johnson et al., 2022). Single-well push–pull tracer tests further quantify aquifer flow, dispersion, cation exchange, and gypsum dissolution parameters that feed sitewide reactive transport models (Johnson et al., 2023).
In the Gunnison Basin, stakeholder roles are more distributed. County commissioners review mining EISs and land-use proposals Homestake Pitch Project Draft EIS, Colorado water courts adjudicate competing claims Mt. Emmons Water Rights Decree, and citizen groups such as POWER (People Opposing Water Export Raids) engage state agencies on trans-basin diversions that could affect contaminant transport pathways Letter to Interstate Stream Investigations from POWER. Local governments like Boulder County also model integrated environmental management approaches, from waste characterization Boulder County Waste Composition Final Report to land-use coordination with state legislators Letter to Linda Powers Re: land use control.
The most pressing technical challenge is that residual solid-phase uranium below excavated tailings can continue to leach into groundwater for decades, especially where gypsum, organic carbon, or low-pH precipitates concentrate uranium in the vadose zone (Johnson et al., 2022). Climate change adds urgency: shifting precipitation, more intense runoff, and changing river stages can alter saturation indices and mobilize previously stable uranium, as suggested by column tests showing that higher-alkalinity river water continues removing uranium from vadose sediments over many pore volumes (Johnson et al., 2022). Hydrogeologic literacy in affected communities — including basic groundwater concepts for residents and decision-makers Hydrogeology 101 — will be critical as cleanup standards evolve.
Looking forward, future directions include incorporating site-specific reactive transport parameters from push–pull tests and column studies into predictive groundwater models (Johnson et al., 2023), evaluating alternative injection fluids that change sorption coefficients, and integrating remediation planning with broader basin concerns such as water exports Letter from POWER, dust control on unpaved roads near disturbed lands Dust Retardant on Roads, and fiscal impacts of large development projects Gunnison Rising Fiscal Impact Memo.
While RMBL's core research emphasizes alpine ecology rather than radiochemistry, the Gunnison Basin's long history of mining proposals connects directly to hydrologic and biogeochemical research themes shared with uranium remediation science: stream discharge measurement using Acoustic Doppler Velocimetry, vadose- and saturated-zone hydrology, and sorption processes on organic carbon all bridge ecological and contaminant studies. Long-term botanical baselines such as those rooted in Harriet Barclay's herbarium collections at RMBL (Lombardi, 2023) provide reference data for evaluating ecological change on lands potentially affected by mining legacies, and riparian science on invasive Tamarix highlights how disturbed western river corridors — including those downstream of mill sites — recover or fail to recover (Johnson et al., 2018).
Boulder County Countrywide Waste Composition Final Report. →
Dust Retardant on Roads. →
Homestake Mining Company, Pitch Project, Draft Environmental Impact Statement. →
Hydrogeology 101. →
Johnson et al., 2018. Invasion and Restoration of Western Rivers Dominated by Tamarix. →
Johnson et al., 2021. Fission-Track Radiography and SEM at Grand Junction Mill. →
Johnson et al., 2022. Column-Test Data and Geochemical Modeling at Grand Junction Mill. →
Johnson et al., 2023. Single-Well Push–Pull Tracer Tests at Grand Junction Mill. →
Legislative Bulletin Special Air Issue, Colorado Open Space Council. →
Letter from CGS Re: Crested Butte Properties. →
Letter to Interstate Stream Investigations from POWER. →
Letter to Linda Powers Re: Land Use Control and Compensation. →
Local Government Participation in A-95 Project Notification and Review System. →
Lombardi, 2023. Harriet G. Barclay's Herbarium Collections. →
Memorandum: Gunnison Rising Fiscal Impact Analysis. →
Mt. Emmons Water Rights Findings of Fact and Decree. →
Historical analysis of gender disparities and barriers faced by women in scientific fields
Letter from P.C. Klingsmith of POWER (People Opposing Water Export Raids) to Mr. Randy Seaholm ( Chief of Interstate Stream Investigations) concerning...
Ralph E Clark. March 22, 1994.
Tom Binnings and Paul Rochette. January 28, 2008.
Alber Vogel, Kathryn Vogel and Michael Wells. Owners/Consumers in Crested Butte and Gunnison County Electric Associations, Inc.. January 2008.
CRESTED BUTTE/GUNNISON COUNTY HOUSING RESEARCH 1992 The Current Housing Situation Fully understanding the housing situation throughout the study area ...
Bill Rosebury. February 12, 2003.
Christine Canaly. Valley Voice.
The Pueblo Chieftain.