By Reid Brown and Rio Diniakos Geomorphic and Biotic Controls on the Transport of Uranium Bearing Dust By Reid Brown and Rio Diniakos

Geology Jackpile Formation  Tabular deposits

Site History -Operational: 1951-1983 -Ore Grade: 0.1-1.3% U3O8 -NPL metals of concern: U 234, 235 & 238, Cr, Mn, Co, V & Zn -Remediation completed in 1995 -Covering and contouring -2007 compliance assessment failed -Proposed to NPL in 2012 -Current Superfund site Area around Jackpile Mine near Pagate, NM

Site History -Operational: 1953-1982 -NPL metals of concern: U 234, 235 & 238, Cr, Mn, Co, V & Zn -Remediation completed in 1995 -Covering and contouring -2007 compliance assessment failed -Proposed to NPL in 2012 -Current Superfund site Locations of Backfill(white), contouring(green), and Waste Rock Piles (Red)

Wind Patterns throughout the seasons Winter Spring Summer

Wind Patterns over the Study Region

Questions We Want to Answer What are the important variables? Can we build a predictive model? Can we source the dust samples? Is there significant difference in the soil and dust samples?

Variables of interest Metals present in the samples: V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Pb, Th, U Geomorphic and Biotic variables: Vegetation type, density, distance from source, and elevation.

Methods Conduct multiple linear regression Random Forest Principal Component Analysis

Multiple Linear Regression Adjusted R2 = 0.02938 for Uranium as the response variable and Elevation, distance, and vegetation as the predictors for the system. P-value = 0.00198

Random Forest: Geomorphic and Biotic Controls Bagging (mtry=4): MSE = 3.75 Random Forest (mtry=2): MSE = 3.51

Random Forest: Important Elements Bagging (mtry=6): MSE = 4.49 Random Forest (mtry=2): MSE = 4.82

Random Forest: Predictive Model

Required Sample Size for Prediction

Contaminant Sourcing

PCA Analysis: Soil and Dust

PCA Analysis: Soil and Dust

PCA Analysis: Dust Only

PCA Analysis: Dust Only

PCA Analysis: Soil Only

Conclusions Density and Vegetation Type are important with respect to [U] Pb and V are important elements Need more samples for a predictive model with useful margin of error 30+ years of mixing has diluted contaminant source signature Difference between dust and soil elemental concentrations Needs additional analysis to determine Higher/Lower Difference between dust collected at bottom half vs top half of stem Needs additional analysis to determine significance Needs analysis to determine differences in specific elements

Questions? Looking south from the north end of the pit: Past and Present