DRC-2013-001383 - 0901a06880350376

Department of
Environmental Quality
Amanda Smith
Executive Director
DIVISION OF RADL\TI0N CONTROL
Rusty Lundberg
Director
State of Utah
GARY R HERBERT
Governor
GREG BELL
Lieutenant Governor
February 21, 2013
CERTIFIED MAIL
(Return Receipt Requested)
Jo Ann Tischler, Director, Compliance
Energy Fuels Resources (USA) Inc.
225 Union Boulevard, Suite 600
Lakewood, CO 80228
:T
IT
ru
IT
O
a a
o
CO
DT a
C2
U.S. Postal Service TM
CERTIFIED MAIL. RECEIPT
(Domestic Mail Only; No Insurance Coverage Provided)
For delivery nformatlon visit our website at wvm.usps.come
o FFICIAL ust
Postage
Certified Fee
$
RE: 2/21/13; FINDINGS & CLOSEOUT /-f
JO ANN TISCHLER
ENERGY FUELS RESOURCES (USA) INC.
225 UNION BLVD., STE 600
LAKEWOOKCO 80228
I
PS Form 3800. August 2006 See Reverse for Instructions
Subject: Energy Fuels Resources (USA) Inc. November 7, 2012 Second Revision
Hydrogeology of the Perched Groundwater Zone in the Area Southwest of the
Tailings Cells White Mesa Uranium Mill Site, Ground Water Discharge Permit No.
UGW370004, Part LH.6.: DRC Findings and Close-out
Dear Ms. Tischler: DRC-2013.001383
The Utah Division of Radiation Control ("DRC") has completed review of the Energy Fuels
Resources (USA) Inc. ("EFR") November 7, 2012 Second Revision, Hydrogeology of the Perched
Groundwater Zone in the Area Southwest of the Tailings Cells White Mesa Uranium Mill-Site
(Revised Report). The Revised Report was submitted in response to a DRC September 20, 2012
Request for Information Letter which included a summary of agreements made between DRC and
EFR by telephone conference on September 18, 2012 and requested that EFR:
1. Repeat slug tests at piezometer/monitoring well DR-8,
2. Recalculate average hydraulic conductivity,
3. Recalculate travel times if necessary based on new calculations,
4. Submit the results of the repeated slug tests and recalculated hydraulic parameters and
travel time calculations (if necessary) on or before November 9, 2012.
Summary of November 7, 2012 Revised Report (Second Revision):
The Revised Report was received by DRC (paper copy) on November 9, 2012 (dated
November 7, 2012. The Revised Report was also received by DRC via e-mail on November 7,
2012 (5:36 P.M.). Therefore, EFR met the agreed upon due date.
195 North 1950 West • Salt Lake City, UT
Mailing Address- P O Box 144850 • Salt Lake City, UT 84114-4850
Telephone [phone] • Fax [phone] 'TDD [phone]
www deq utah gov
Pnnted on 100% recycled paper
Jo Ann Tischler
Page 2
The November 7, 2012 Revised Report provides the following:
1. A red line copy of the November 7,2012 Revised Report, which includes deleted text and
added text, as changed from the previous August 3, 2012 Revised Report.
2. A final black line copy of the Novernber 7, 2012 Revised Report which accepts the
changes. The final copy is certified (signed and stamped) by Stewart J. Smith P.G., Hydro
Geo Chem, hic. ("HGC"),
3. Copies ofthe tables and figures in black line form which reflect the changes made in the
Revised Report. The tables and figures include a plot of the DR-8 raw data and overlay of
displacement values which were corrected due to atmospheric pressure changes during the
test. DRC additionally requested a plot of the atmospheric pressure data collected during
the test on February 12, 2012 (A.M.); the plot and data was received via e-mail from EFR
on February 12,2012 (P.M.).
DRC Findings — EFR Repeat Slug Tests and Data Analyses at Piezometer DR-08
Well Development:
DRC noted during review of the Revised Report that details of well development at DR-8 were
not included. Per DRC e-mail communication with EFR on February 7, 2012 it was verified by
EFR that none of the Dry Ridge (DR) piezometers/monitoring wells, including DR-8, underwent
well development.
Professional guidance and literature concerning the application of slug testing to calculate aquifer
parameters stress the importance of thorough well development prior to the implementation of the
testing.
Per Butler 1997^ p. 5 "Importance of well development - slug tests are extremely sensitive to
near-well disturbances; so, it is no exaggeration to say that the success of a program ofslug tests
critically depends on the effectiveness of well development activities. Repeat slug tests and
preliminary screening analyses will be the primary approaches recommended here for assessment
ofthe effectiveness of well-development activities'''
Failure to conduct well development increases the likelihood that a low permeable well skin at
piezometer/monitoring well DR-8 may exist and may be contributing or causing low hydraulic
conductivity estimates.
Slus Test Method
Per Butler 1997p. 27 it is noted that that the primary direction of flow during a series of slug tests
should be from the formation into the well (slug-out) as ''slug-induced flow from the well into the
formation will often lead to decreases in hydraulic conductivity as a result of mobilized fine
material being lodged deeper in the formation^
^ James J. Butler, Jr. 1997, Lewis Publishers, The Design. Performance, and Analysis of Slug Tests
Jo Ann Tischler
Page 3
Counter to this, EFR conducted slug tests at the Dry Ridge Piezometers/Monitoring Wells,
including DR-8 from the well into the formation (slug-in). It is also noted that EFR conducted
only a single slug-in test at the Dry Ridge Wells/Piezometers, with a retest (slug-in) at well DR-8.
Per Butler 1997, a. series of three slug tests (two slug-in tests and one slug-out test) is
recommended to be conducted in order to verify reproducibility of the tests (no interference from
low permeable well skin) as well as analysis of potential changes in effective screen length during
the test.
Barometric Pressure:
The Dry Ridge Piezometers were originally slug tested during October, 2011. Piezometer DR-8
was retested on October 9,2012. The re-test was conducted by EFR in response to DRC letters
dated May 30,2012 and September 30,2012.
The re-test followed the same general procedure as the October, 2011 slug test, using
automatically logged data with a pressure transducer as well as a second set of hand collected data
using an electric water level meter. The test differs in that the October, 2012 initial displacement
was roughly half of the previous testing. The re-test used an approximate 0.23 gallon slug, the
initial test used an approximate 0.47 gallon slug. A pressure transducer was used to record
barometric pressure during the re-test; the November 7,2012 Report states that ''the automatically
logged data were corrected for changes in atmospheric pressure prior to analysis and processed
in substantially the same fashion as for the October, 2011 tests"
DRC staff has previously observed, during inspections of 2003 pump tests (using observation
wells), that barometric pressure changes appear to impart an immediate ground water level
response in the Burro Canyon aquifer in the region. Per DRC review ofthe HGC barometric
pressure data during the October 2012 DR-8 retest, and comparison with the HGC displacement
plot ofthe raw data collected during the test, there does appear to be an immediate systematic
relationship between the two parameters.
DRC Findings Resardins the DR-8 Re-test Data Analysis:
The analysis results of the KGS and Bouwer-Rice solutions using the October 2012 slug test data
at DR-8 differ by an order of magnitude for hydraulic conductivity. Resuhs of the EFR analyses
(first test and retest) are below:
Table 1: EFR resuhs ofthe October, 2011 slug test
2011 Automatically Logged Data Hand Collected Data
KGS Bouwer-Rice KGS Bouwer-Rice
Test Saturated K Ss K K Ss K
Thickness (cm/s) (1/ft) (cm/s) (cm/s) (1/ft) (cm/s)
DR-8 7.7 3.43E-08 l.OOE-02 8.10E-08 l.OlE-07 1.18E-03 Not
Interpretable
Jo Ann Tischler
Page 4
Automatically Logged Data Hand Collected Data
KGS Bouwer-Rice KGS Bouwer-Rice
Test Saturated K Ss K K Ss K
Thickness (cm/s) (1/ft) (cm/s) (cm/s) (1/ft) (cm/s)
DR-8 7.8 2.46E-08 l.OOE-02 3.56E-07 4.46E-08 l.OOE-02 4.45E-07
Per the revised November 7, 2012 Report language. Section 2.3.3, "Differences between hydraulic
conductivity estimates obtained using the KGS and Bouwer-Rice solutions are common and
expected because of the differences between the two solution methods. The KGS solutions
accounts for non-steady flow and aquifer storage while the Bouwer-Rice solutions does not.
Accounting for non-steady flow and storage allows a fit to the entire data set using KGS rather
than typically only the later-time portion of the data using Bouwer-Rice.''''
It is not clear how EFR is conceptualizing non-steady flow at DR-08. The radial flow equation
(Theim Equation) used for Bouwer-Rice analysis should be adequate for calculation of hydraulic
conductivity; Per Butler 1997p. 120 it is noted that for piezometers/wells screened across the
water table the Bouwer-Rice method is appropriate as long as the flow system (position ofthe
water table and effective screen length) are not changing significantly during the course ofthe
test. DRC notes that the data fit for the Bouwer Rice analysis, per the Revised Report Appendix
D, appears to be good based on the corrected data set.
Conclusions
Based on the DRC Staff findmgs above, the October 2012 slug testing (re-test) at
piezometer/monitoring well DR-8 meets the objectives and timelines as agreed to between DRC
and EFR staff.
Per DRC confinnation from EFR, via e-mail dated February 7,2012, DR-8 was not developed;
additionally, DRC notes that none of the DR boreholes/wells which were used to estimate
permeability values and average linear groundwater velocity for the study underwent well-
development. Although DRC findings regard this as an oversight by EFR, it is recognized that the
creation of a wellbore skin in the DR piezometers/monitoring wells was minimized through the
use of air rotary drilling methods.
Per above DRC additionally noted that a single slug test, as implemented by HGC, is not adequate
to evaluate potential interferences due to near well disturbance. Although the use of a single test
is not ideal, it is recognized that the DR tests were conducted within formations with very low
hydraulic conductivity and that the test durations were extremely long; Longer and unfeasible
amounts of time would be required to implement multiple tests and to provide frill hydrostatic
recovery with rising head techniques.
Development of the wells and retesting is not warranted based on the objectives of the Southwest
Hydrogeology Study. Both DRC and EFR recognize that the calculated hydraulic parameters
Jo Ann Tischler
Page 5
using slug test data, included in the Revised Report, provide only a rough estimate of the aquifer
hydraulic conditions and subsequent calculation of groundwater velocities.
These issues were discussed and agreed to during a February 13, 2012 close-out conference call
amongst Phil Goble (DRC), Tom Rushing (DRC), Jo Ann Tischler (EFR), Kathy Weinel (EFR),
and Stewart Smith (HGC).
It was also discussed during the close-out conference call that additional actions regarding the DR
piezometers/monitoring wells may be required based on DRC review of the EFR Revised
Hydrogeologic Report, as required by the EFR White Mesa Uranium Mill Ground Water
Discharge Permit, Permit No. UGW370004 ("Permit") Part I.F.10.
Close-out
Based on DRC review, it appears that the Revised Report is in compliance with the requirements
of the Permit Part I.H.6 {Compliance Schedule Requirements for the Detailed Southwest
Hydrogeologic Investigation). The review is therefore closed-out; note that Part.I.H.6 will be
removed from the Permit at renewal.
If you have any questions regarding this letter, please contact Tom Rushing at [phone].
Sincerely,
Rusty Lundberg
Director
cc: Charles Bishop, DRC
John Hultquist, DRC
RL:TR:tr
F:\Energy FuelsNSouthwest InvestigationXNovember 7,2012 Revised HGC ReportNSecond Revised EFR Southwest Hydro Report DRC Findings
and Close-out docx