1. Colorado River Protection Activities on the Moab UMTRA Project Ken Pill, Hydrogeologist Technical Assistance Contractor CMU Upper Colorado River Basin Water Forum October 31, 2011

2. Site Setting 2 Matheson Wetlands Preserve Moab Colorado River Well Field Tailings Pile Evaporation Pond Moab Wash

3. Site Background and Scope Former uranium ore-processing facility 1956 to 1984 480-acre site, 130 acres covered by mill tailings pile Toe of pile is 750 ft from west bank of Colorado River Relocate 16 million tons of uranium mill tailings to engineered disposal cell Actively remediate ground water at Moab site Endangered fish species habitat protection 1984 3

4. 4 Ground Water Conditions

5. Ammonia Plume June 2011 data Ammonia toxicity pH and temperature dependent Toxicity increases at higher pH values 5

6. Ground Water Remediation Currently extracting ground water closer to the toe of the tailings pile All extracted ground water pumped to a lined evaporation pond located on the top of the tailings pile Capability to inject diverted Colorado River water into 34 injection wells along the riverbank Ground Water Extraction Fresh Water Injection Evap Pond Toe of Tailings Pile 6

7. 7 Mass removal rates have increased over the past 5 years Evaporators used to replace pile sprinkler system As of October 2011 have removed 699,000 lbs of ammonia 3,200 lbs of uranium Ground Water Remediation (continued)

8. Evaluating Long-Term Treatment Options Treatability study Russ Walker, CMU Dept of Physical and Environmental Sciences Prepared conceptual design for chemical ground water treatment system Golder and Assoc pH adjustment with lime for U ppt Shallow settling ponds with aeration at pH = 10.5 for NH 3 removal 8

9. 9 Impacts of River Stage on Water Chemistry Flow ~3,700 cfs Base flow conditions — Gaining river Stiff diagrams illustrate differences between water chemistry

10. 10 Impacts of River Stage (continued) Flow ~35,900 cfs Peak runoff conditions — Losing river Fresh water lens migrated ~40 ft bgs and 150 ft laterally

11. 11 Fresh Water Injection After fresh water lens developed due to runoff, supplemented with injection Operating consistently since 2010 Have injected 9 million gallons through October 2011 Oct 2011 Ammonia (mg/L)

12. 12 Suitable Habitat Potential Closed upstream, open downstream After spring runoff peak through September 30 Base Flow Conditions (~3,250 cfs) Side Channels

13. 13 Habitat Potential (continued)

14. 2011 Flooding Worked with Utah Division of Wildlife Resources to rescue native fish from ponded water after river receded 14 June 9, 2011 48,500 cfs

15. Moab Project Information gjem.energy.gov/moab Webcam view of Moab site 15

16. Questions? 16