Uranium in shallow groundwater in the Basin,

B.Welsh, M.C. Moncur, D. Paktunc, Y. Thibault, S.J. Birks, M. Weiser, and B. McKiernan

Alberta Lake Management Society Presented by: 19th Annual Workshop Brent Welsh, P.Eng. , September 29, 2012 District Hydrogeologist Operations, Northern Region Environment and Sustainable Resources Development Government of Alberta Issue

• Uranium (U) up to 170 μg L-1 reported in shallow (< 25 m) domestic wells near Bonnyville, Alberta • Health Canada IMAC for U is 20 μg L-1

Athabasca Basin Ore Deposit Anthropogenic Activity

Active Oil and Gas Wells Water Wells

(Lemay et al., 2005) (Parks et al., 2005) Anthropogenic Activity

Agriculture Water Wells

(Lemay et al., 2005) (Parks et al., 2005) Anthropogenic Activity

Municipal / Commercial Water Wells

(Lemay et al., 2005) (Parks et al., 2005) Typical Anthropogenic Sources

Emissions and heavy Emissions from water from nuclear Coal combustion energy

None of these sources are present Drainage from in Beaver River Basin Mining operations Potential Local Sources ?

Field Applied Fertilizers

Indirect Causes: Sprayed Drill Cuttings

Weathering of U in Soil due to over pumping Poor Well Produced Water from Completion: Oil and Gas Wells

Multi-aquifer completion or poor annular seal (mixing or short circuiting) NORMS – Pipe Scale Uranium in Soil

• Naturally occurring radioactive element found in all rock and soil (1 to 4 mg kg-1) (Drever, 1982) • BRB, Alberta: U = 3 to 5 mg kg-1 (Andriashek, 2000)

Uraninite Surficial Geology Grand Centre Formation

Quaternary Geol.: Regional Aquitard with Comparatively Local Aquifers high granitic rock content derived K = <1 to 14 m/d from Canadian Shield (U carrier) Source of Water for 4/5 wells at Down glacier from Site 1 Athabasca Basin U ore deposit GW Flow: Fractures in Till and discontinuous sands act as preferential pathways (Modified from Parks et al., 2005) Uranium in Groundwater

• Mobile in oxidized GW with near neutral pH – U(VI) • In reducing conditions, U decreases due to precipitation reactions – U(IV)

U Roll Front Deposit

(Image: Matveeva & Anderson, 2007) Uranium from Soil Weathering

4+ 2+ + U + ½O2 + H2O → UO2 + 2H

1000s of years

U from soil to GW in Canada: Milk River Aquifer, AB (Ivanovich et al., 1991) Central (Ranville et al., 2007) Manitoba (Betcher et al., 1998) Northern Ontario (Gilliss et al., 2004) Uranium from Soil Weathering Quaternary Geology 6 Regionally Mapped Aquifers Correlated Formation: with Interglacial Melting Events, Source of Water at Erosion, and Site 2 and 1/5 wells at Site 1 Deposition Most Popular and Aquifers confined by shallowest Aquifer Clay-till aquitards

Empress Formation:

Unit 3 - Glacial (Quaternary Period)

Unit 1 - Preglacial (Modified from Parks et al., 2005) (Neogene Period) Objective & Approach

• Conduct an investigation at two sites to determine if source of elevated U is natural or anthropogenic – Install nested piezometers for groundwater (GW) geochemical and isotopic sampling – Core sediment for sampling, mineralogical analyses, and pore water extraction from clay till aquitards • This Presentation will focus on Site 1 Well Locations Site 1 Produced Water Sampling Site

Fertilizer sampling sites Site 1-C Battery

Energy Well Site 1-B

Site 1-A

Well 3 Well 2 MW2

Well 5 MW1 Well 4 Well 1

HWY 659

Wells 1 to 4 = Domestic Wells Shallow Wells: Well 5 = Commercial Well Depth < 25 m MW1 to 2 = Piezometers Uranium Concentrations in GW and Produced Water

) 160 -1

120 No annular seal Aquifer 1 80 Aquifer 2 -1 MAC = 20 ug L Aquifer 3 40 Aquifer 4 0.09 Uranium (ug L (ug Uranium 0

MW2 Well4 Well2 Well3 Well5 Well1 E. Well E. MW1-3 MW1-1 MW1-2

August 24, 2011 Update: Well 1 = 167 μg L-1 Produced Water Oil Battery Uranium Concentrations in Sediment Site 1

Background U: Fe (mg kg-1) Al (mg kg-1) U (mg kg-1) As (mg kg-1) 0 14000 28000 0 33000 66000 0 2 4 0 3 6 3 to 5 ppm 0

5 Fertilizer: Location U (ppm)

Depth (m) Depth 10 Sample 1 1.51 Sample 2 1.29 15 Sample 3 1.19 Ca (mg kg-1) Mg (mg kg-1) Na (mg kg-1) K (mg kg-1) 0 25000 50000 0 10000 20000 0 6000 12000 0 15000 30000 0

5 Drill Cuttings: Location U (ppm)

Depth (m) Depth 10 Sample 1 2.96

Sample 2 2.01 15 Sample 3 1.85 Oxidized Clay-Till Unoxidized Clay-Till Sand Pore Water Site 1

pH -1 -1 µ -1 -1 Eh (mV) Alk (mg L ) SO4 (mg L ) Fe ( g L ) U (µg L ) 6 8 10 -200 0 200 0 300 600 0 1500 3000 0 900 1800 0 30 60 0

5

10 Depth (m) Depth

15 -1 K (mg L-1) Na (mg L-1) Ca (mg L-1) Mg (mg L-1) Cl (mg L-1) Si (mg L ) 0 15 30 0 550 1100 0 600 1200 0 550 1100 0 800 1600 0 15 30 0

5

10 Depth (m) Depth

15 Oxidized Clay-Till Unoxidized Clay-Till Sand Speciation Modeling

PHREEQC (Parkhurst and Appelo, 1999) WATEQ4F Data Base (Ball and Nordstrom, 1991)

SI = log IAP/Ksp

SI > 0: Supersaturated (Precipitation) SI < 0: Undersaturated (Dissolution) SI = 0: At Chemical Equilibrium

Speciation Modeling Site 1

Calcite Dolomite Siderite Ferrihydrite Goethite Gibbsite α-FeOOH CaCO3 CaMg(CO3)2 FeCO3 5Fe2O3A9H2O Al(OH)2 -2 0 2 -3 0 3 -6 0 6 -6 0 6 0 4 8 -2 0 2 0

5

10 Depth (m) Depth

15 4+ 6+ Uraninite Amorphous Coffinite Schoepite Rutherfordine Gummite U4+O U4+O U4+SiO 6+ U6+O CO U6+O 2 2 2 U O2(OH)2AH2O 2 3 3 -16 -6 4 -20 -10 0 -16 -6 4 -8 -4 0 -8 -4 0 -14 -7 0 0

5

10 Depth (m) Depth

15 Oxidized Clay-Till Unoxidized Clay-Till Sand Mineralogy a) Near end- Evolution of member zircon desiccation cracks in dark region b) Ca-, Fe-, P- (from c to d) from bearing zircon electron beam (desiccation exposure cracks) Indicates partial Metamict hydration; Zircon yielded low totals c) and d) single Alteration & zircon grain Dissolution of showing Metamict Zircons: coexisting end- member Delattrie et al., 2007; Hay & Dempster, (bright) and 2009; Ca-, Fe-, P- Tromans, 2006 bearing growth zones (dark). BSE images showing distinct zircon appearances

Average [UO2] = 1050 ppm; Range [UO2] = 90 – 4500 ppm Secondary Precipitate Site 1

• Monohydrocalcite • Aragonite • Hydromagnesite • Nesquehonite Uranium Speciation – IV • Gypsum Normalized U LIII-edge XANES spectrum • U content: 143 ppm

BSE image of representative area fragment dominated by monohydrocalcite (colloform growth) Note: Arrow points to characteristic post-edge feature of VI Speciation Modeling Site 1

Calcite Aragonite Siderite Magnesite Nesquehonite Gypsum Mg(HCO )(OH) 2H O CaCO3 CaCO3 FeCO3 MgCO3 3 2 CaSO4 2H2O -2 0 2 -3 0 3 -6 0 6 -2 0 2 -4 -2 0 -3 0 3 0

5

10 Depth (m) Depth

15 4+ 6+ Uraninite Amorphous Coffinite Schoepite Rutherfordine Gummite U4+O U4+O U4+SiO 6+ U6+O CO U6+O 2 2 2 U O2(OH)2AH2O 2 3 3 -16 -6 4 -20 -10 0 -16 -6 4 -8 -4 0 -8 -4 0 -14 -7 0 0

5

10 Depth (m) Depth

15 Oxidized Clay-Till Unoxidized Clay-Till Sand Uranium Isotopes Site 1 and Site 2 Other studies: 90 Site 1 MR Aquifer, AB Site 2 109-646 ppm 80 (Ivanovich et al., 1991)

Granitoid Aquifer, ) S. Brazil 70 99-219 ppm

(Reyes & Marques, 2008) ppm

60 234 Lower values indicate U ( Preferential U weathering in GW mixing with depleted Equilibrium Value 238 end-member 50

(i.e., precipitation) U/ 236 234 U was not 40 detected in any samples Uncertainty: 30 2σ = ±10 ppm

20 Health CanadaIMAC 234 U λ238 0 20 40 60 80 100 120 140 160 180 200 220 = ⋅ A234 238U λ -1 234 238 U (μg L ) A = activity ratio Test Method: MC-ICP-MS with SEM (Wiezer & Schwieters, 2005); U Standard: IRMM-3184 Regional Observations Grand Centre Formation

U Concentrations Uraninite SIs

Uranium (µg/L) Uraninite (UO2) Regional Observations U Concentrations Uraninite SIs ALMS U Results: Beaver River Basin

20 Lake U Concentration influenced by:

) - 1 15 - Available source of U - Lake and GW Geochemistry - GW inflow - Residence time 10 - Available U sinks - Evaporation

5 Uranium (total) (µg (µg L (total) Uranium

0

Source: ALMS 2007-2012 Conclusions

• There is no indication that anthropogenic sources contributed to U in GW • The primary source of U in shallow aquifers is due to the weathering of overlying sediments – Redox conditions are oxic, conducive to U(VI) mobilization – Speciation modelling indicates U(VI) is under saturated – Mineralogical analyses indicate the major U source is metamict zircon – Isotope ratios from the two sites indicate shallow weathering and mixing with precipitation • Regional mapping indicates problem is localized, shallow, and dependent on U(IV) mineral saturation • Uranium is unlikely to ever exceed the current irrigation guideline in Beaver River Basin lakes Environment and Sustainable Acknowledgments Resource Development

Funding: • Beaver River Watershed Alliance • Alberta Health and Wellness • Alberta Environment and Sustainable Resource Development • Natural Sciences and Engineering Research Council of Canada (NSERC)

XAFS experiments were performed at the PNC/XOR beamline, Advanced Photon Source, Argonne National Laboratory supported by the US Department of Energy under Contracts W-31-109-Eng-38 (APS) and DE-FG03-97ER45628 (PNC-CAT)

We thank: The Well Owners, Joe Prusak, Debra Mooney, John Gibson, Danielle Cobbaert, Mary Raven, Vien Lam, and Eleanor Kneffel for their support Water for Life Knowledge and Research Series:

Moncur, M.C., Paktunc, D., Thibault, Y., Birks, S.J., Wieser, M. (2011) Uranium and Arsenic Sources in Shallow Groundwater Near , Alberta: A Mineralogy Study http://environment.gov.ab.ca/info/posting.asp?assetid=8599&searchtype=asset&txtsearch=uranium

Moncur, M. (2010) Uranium Anomalies in Shallow Groundwater Near Bonnyville, Alberta http://environment.gov.ab.ca/info/posting.asp?assetid=8373&searchtype=asset&txtsearch=uranium