Presentation by Jim Oliver of Crestone Environmental, LLC on uranium mine cleanup efforts for the Navajo Nation. Presented at the September Rocky Mountain UAS Professionals Meetup at the Wings over the Rockies Air & Space Museum in Denver, Colorado.

1. Use of UAV Assessment in Navajo Nation
Abandoned Uranium Mine Cleanup – Cameron Chapter
Jim Oliver, RG
Crestone Environmental, LLC
Technology Advisor
Joliver@crestone-env.com

2. Navajo Abandoned Uranium Mine (NAUM) Sites
• Estimated 3,700
Sites in Four
Corners Area
• 523 AUM Sites on
Navajo Nation
• $1 Billion allocated
to cleanup 46 sites
• EPA currently has
assessment scope
for $85 Million

3. Common Methods Difficult to Apply at NN AUMs
> Often on cliffs or high relief
terrain
> Many areas inaccessible
> Unknown uranium
concentrations
> Difficult to distinguish
background from mine waste
> Cleanup volumes are rough
estimates
Mine Portal
Waste Rock

4. Common Methods to Assess AUM Contamination
GPS Unit
Gamma Sensor

5. Generalized Multi-Sensor UAS Data Workflow for AUM Assessment
Identify Investigation Boundary – Mining Area, Background,
Haul Roads, Waste Piles and Drainages
Fly UAS LiDAR and Imagery Within Investigation Boundaries.
Process LiDAR to Develop Site Specific Digital Elevation Model
Fly Multi-Spectral Gamma Sensor(s) at Constant Elevation
Based on Pre-determined Site DEM
Assess Decision Units (DUs) distribution and Background
Concentration Distribution
Collect Statistically Relevant Confirmatory Soil Samples
locations for COCs in DUs and Background Areas
Quantify Nature, Extent and Volume of Mine Waste Above
Background
Patent Pending
AUM UAV
Workflow
Cardno/Crestone

6. Flight Platform: Pulse Vapor 55 VTOL UAV

7. Sensor Package
LiDAR
• Terrain mapping
• Volume
quantification
• Vegetation layer
• Change detection
• Feature detection
Gamma
• Uranium
contamination
• Migration
Pathways
• Background
Imagery
• Vegetation
assessment
• Cultural resources
• Photogrammetry
• Geological
correlation

8. Flight Operations – CAM 27 AUM Near Cameron
• 15 acre coverage
• Pre-set Flight Plan
• 11 minute data collection time
• 75 foot spacing on flight lines
• Photogrammetry
• Full survey grade ground
control
• 150 and 100 ft gamma flights
• 5 points per sec
• 4,200 total gamma
measurements

9. Safety Systems in Flight Operations

10. Imagery Flight Plan

11. Mine Cap – Erosional Feature

12. Gamma Data – Level of Radiation from Uranium
> Data provided in Counts Per Second
(CPS) along flight path
> As part of the future work, will convert
the CPS data into units that will be
used to assess cleanup levels

13. CAM 27 AUM
• Background concentrations
outside of mine site (blue)
• Higher concentrations near
former mine operations (red)
• Gamma emissions from cap
erosional features (Red)
• Elevated gamma readings
associated with haul roads
(light red)

14. Tso Property
• Background concentrations
over most of property (blue)
• Small area south of home
site across road (yellow)
• Much lower overall as
compared to mine site

15. Unique RPAS Multi-Sensor Workflow
> Full understanding of
contamination distribution
and volume
> Improved repository
design
> Less cost and more data
than conventional walk
around survey
> Post cleanup confirmation
> ALARA says so!
> EPA behind the curve