DRC-2012-001268 - 0901a068802bc90c

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State of Utah
GARY R HERBERT
Governor
GREG BELL
Lieutenant Governor
March 19 2012
Department of
Environmental Quality
Amanda Smith
Executive Director
DIVISION OF RADIATION CONTROL
Rusty Lundberg
Director
CERTIFIED MAIL
(Return Receipt Requested)
DRC- 2012-00 1268.
David C Frydenlund Vice President Regulatory Affairs and Counsel
Denison Mines (USA) Corp
1050 17* Street Suite 950
Denver CO 80265
Subject Nitrate Corrective Action Plan for the White Mesa Mill Site dated February 27 2012
DRC Review Comments
DearMr Frydenlund
The Division of Radiation Control (DRC) review comments regarding the February 27 2012 Denison
Mines (USA) Corporation (DUSA) Nitrate Corrective Action Plan for the White Mesa Mill Site are
enclosed (via URS Memorandum)
DRC anticipates that DUSA should be able to respond to the comments and submit a revised CAP on or
before Monday Apnl 23 2012 If DUSA does not agree with this due date then please request an altemate
date including justification(s) for the extension on or before close of business March 22 2012
If you have questions or concems regarding the comments or would like to arrange a meeting or
teleconference to discuss the comments please contact Tom Rushing at [phone] Thank you
Sincerely
UTAH WATER QUALITY BOARD
Rusty Lundberg
Co Executive Secretary
Enclosure URS Memorandum (5 pp)
F \DUSA\Nitrate Corrective Action Plan\2 27 12 Revised CAP\URS DRC CommentsXNitrate CAP 2 27 12 DRC Comments Cover Ltr docx
195 North 1950 West Salt Uke City UT
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URS
MEMORANDUM
To Phil Goble (DRC) Tom Rushing (DRC)
From Paul Bitter (URS) Jeremy Cox (URS) Jon Luellen (URS)
cc Robert Baird (URS)
Date 19 March 2012
Re Comments on the Revised Corrective Action Plan for Nitrate White Mesa Uranium
Mill Near Blanding Utah dated Febmary 27 2012
This memorandum contains the comments by URS and the Utah Department of Environmental
Quahty Division of Radiation Control (DRC) on the revised Corrective Action Plan for Nitrate
at the White Mesa Mill Site The revised Corrective Action Plan (CAP) was prepared for
Denison Mines USA (DUSA) by Hydro Geo Chem Inc and was dated February 27 2012
Comments have been provided by URS as a deliverable for Contract No 116259 issued through
the DRC This review also is in accordance with the amended Memorandum of Understanding
(MOU) between the DRC and DUSA dated December 2011 For purposes of expediency the
URS and DRC comments are edited for conciseness and combined into one memo Note that
format grammar and punctuation in the revised CAP were not reviewed for accuracy and
consistency
The comments regardmg the revised Corrective Action Plan for Nitrate dated February 27 2012
are presented below A relatively large amount of text has been added to the CAP since the
November 2011 draft version and a number of new topics have been mtroduced which has
required an additional level of review The deficiencies that have been identified during this
review must be addressed in order to fully satisfy the requirements of the September 30 2011
Stipulated Consent Agreement Docket No UGW09 03 A (SCA)
1 General comment Replace all instances of discreet with discrete when discussing
sampling
2 General comment DUSA should include a statement that every reasonable effort will be
made to ensure that corrective action implementation effort for the nitrate plume is performed
in a manner that is mutually compatible with and integrated with the corrective action
implementation effort for the chloroform plume in terms of scope and operation to ensure the
effects of corrective action operations for the nitrate plume do not impede or substantially
reduce the effectiveness of corrective action operations for the chlorofonn plume and vice
versa
3 Section 4 3 last paragraph Please replace permeability with conductivity and define
KGS
4 Section 4 3 2 second paragraph The revised CAP appears to state that the groundwater
mound at TWN 2 (which is illustrated in Figure A 2) is a residual effect ofthe histoncal pond
Page 1 of 4 URS
that has persisted due to enhanced infiltration of precipitation before recent re grading ofthe
land surface in that area and low permeability conditions at TWN 2 Please defme
recent m this context If nitrate concentrations in well TWN 2 and the groundwater
mounding observed in this area do not decrease during Phase II a re examination of the
elevated nitrate concentrations and its possible source(s) and groundwater elevations in this
well should be conducted during Phase III Additionally please replace permeability with
conductivity
Section 5 1 second paragraph The revised CAP states that records or information have not
been obtained to evidence the actual uses of the [histoncal] pond over the years Because no
records are available to document uses of the pond all of the followmg sentences m this
paragraph regarding nitrate and chlonde concentrations in the pond water and potential
impacts on the perched groundwater quality are unsubstantiated The last four sentences in
this paragraph must be deleted
Section 7 third paragraph first sentence Please add the clanfication that Phase III if
required will be conducted m consultation with the Executive Secretary
Section 7 111 third paragraph After further consideration by DRC the soil screening levels
for the potential 54 soil core samples (per Part 7 1 1 1 of the CAP) to determine the final
extent of the concrete cover and future soil removal volumes should be based on the 2 X UCL
concentration of Nitrate + Nitrite (as N) and Ammonia (as N) instead of 20 X UCL
concentrations as was stated in previous comments made by the DRC These screening levels
are set to 4 29 mg/kg for Ammonia (as N) and 4 384 mg/kg for Nitrate + Nitrite (as N) to
mamtain consistency with the previous investigations of nitrate sources at the site These
concentrations were established in the Preliminary results from Nitrate Phase 1 Investigation
data mass balance and mass balance memo submitted by DUSA via e mail on August 1
2011
Figures 11 2A and 11 2B It would be helpful to show sample locations GP 25B and GP
26B on these drawings
Section 7 114 fourth paragraph DUSA proposes to increase the reporting limits (RLs) for
nitrate and ammonia m soil The RLs for nitrate and ammonia as reported in the tables
transmitted to DRC on August 1 2011 by DUSA were 0 01 and 0 05 respectively These
RLs corresponded to dry weight compositions of approximately 0 24 mg/kg for nitrate and
1 1 mg/kg for ammonia The revised CAP proposes RLs that are an order of magnitude
higher (0 1 mg/kg and 0 5 mg/kg respectively) based on detections in method blank samples
in 2011 Increasing the RLs by an order of magnitude would result in samples containing up
to 2 4 mg/kg of nitrate as N and 11 mg/kg ammonia as N being classified as non detect
These concentrations significantly exceed the estabhshed background levels discussed in
comment #7 above While blank interferences dunng the 2011 are acknowledged the
analytical results presented in 2011 were appropnately flagged when the analytical result was
less than five times the measured concentration in the method blank The RLs and reporting
procedures from the 2011 mvestigation should be retained
Page 2 of 4 URS
10 Section 7 115 fu-st paragraph DI water from the Mill should not be used to decontammate
sampling equipment or provide rinsate samples The DI water should come from a
commercial third party source as specified by the May 2011 revised Phase 1 Work Plan
11 Section 7 1 4 DUSA proposes to place the contaminated soil into the tailings cells dunng a
future excavation DUSA needs to demonstrate m this section at least approximately that
there is sufficient space in the tailmgs cells upon facility closure to accommodate the nitrate
contaminated soil
12 Section 7 2 first paragraph at top of Page 37 The discussion of pynte and the possible
oxidation of pynte is hindered by the lack of quantitative evidence of how much pynte is
present in the borings or how much of the pynte may be oxidized A separate study is
cunently being undertaken by DUSA to quantify the amount of pynte m the formation as
part of a separate investigation of sources of decreasing pH trends and Out of Comphance
status at several of the White Mesa monitoring wells Please provide language explaining
that the oxidation of pynte in the formation has not been substantiated with quantified core
analysis or remove any references to pynte in the Nitrate CAP The presence of
dichloromethane which is the product of microbially mediated anaerobic degradation of
chloroform is sufficient evidence that there are some localized zones within the saturated
zone that may be anaerobic Additionally if the responses to comments provided in the
DUSA cover letter dated 27 February 2012 are to be incorporated into the CAP then the
response to comment 23 ofthe previous round of comments (19 January 2012) should be
similarly revised
13 Section 7 2 third paragraph on Page 39 and Section 8 second paragraph Please clarify that
containment and hydraulic control of the nitrate plume that will prevent physical expansion of
the nitrate plume (as required by the SCA) will be quantified by (1) nitrate concentrations
below the 10 mg/L Groundwater Quality Standard in samples collected from monitonng
wells downgradient of TWN 22 and TWN 24 and (2) demonstration of a hydraulic capture
zone that mcludes all of the nitrate plume upgradient of TWN 22 and TWN 24 through
groundwater elevation data Note that the four cntena listed in Section 8 do not require
modification since they account for these two factors
14 Section 7 2 last paragraph and Section 8 second paragraph This text implies that no actions
would be taken if nitrate concentrations in downgradient wells increase but do not exceed 10
mg/L If nitrate concentrations m any of the wells exceed their respective Ground Water
Compliance Limit (GWCL) listed m Table 2 of the current Permit which are less than 10
mg/L then notification is required and sampling frequencies for the wells is required to be
accelerated per the White Mesa Mill Groundwater Discharge Permit (GWDP UGW370004)
Part G 1 Please revise the text accordingly
15 Section 7 2 1 Clanfy in this section that Wells TWN 1 TWN 2 TWN 3 TWN 4 TWN 7
and TWN 18 will be retained for Quarterly Nitrate and Chloride monitoring as well as field
collection parameters per the approved field collection form (includmg water level
measurements) and wells TWN 14 and TWN 19 will be retamed for Quarterly water level
monitonng only Please also add wells TW4 6 and TW4 16 for water level monitoring
Page 3 of 4 URS
16 Section 722 Table 1 includes a Nitrate Operations and Maintenance Plan but such a
document is not discussed in Section 7 2 2 A bnef description of the plan should be added to
this section or another appropriate section
17 Sections 7 2 2 8 3 and 9 0 (all) These sections discuss the procedures to be used for
conveying pumped groundwater to the tailings cells for disposal Contingency Plan
procedures as presented in Sections 8 1 through 8 4 include procedures to be followed if
groundwater pumping recovery rates drop from anticipated production levels The CAP
needs to include a discussion of procedures/measures to be taken for handling of pumped
groundwater if pumped groundwater inventones conveyed to the tailmgs cells are found to
lead to exceedances in maximum allowable specified threshold values (e g maximum
allowable daily water level) in a cell containment system s leak detection system
18 Section 724 second paragraph To be consistent with the Ground Water Monitonng
Quality Assurance Plan dated March 22 2010 the required purge volume is two casing
volumes and stabilization of field parameters not three pore volumes as stated in this
paragraph In this paragraph and elsewhere m the report ensure that groundwater sampling
procedures are consistent with the currently approved Quality Assurance Plan (QAP)
(Currently Approved QAP dated 3/22/2010 Revision 6)
19 Section 7 3 If Phase II active remediation efforts through groundwater pumping do not
remediate all nitrate concentrations equal to or less than 10 mg/L at the TWN/TW4
monitonng wells and equal to or less than GWPL s at the MW monitonng wells within a
time frame specified below then further consideration of altemate remediation technologies
will need to be evaluated per Phase HI DRC sees a 5 year time frame for limitation of Phase
II implementation as suitable to demonstrate the effectiveness of Phase II groundwater
pumping elimmation of the nitrate plume and remm of the facility monitonng wells to
compliance with Ground Water Quality Standards and GWCL s If definitive evidence does
not show plume elimination and compliance withm the 5 year timeline then DUSA will be
required to submit a revised CAP for Executive Secretary Review and Approval for Phase III
Please include language m the CAP that acknowledges the Phase II compliance time
limitation
20 Section 8 2 and Section 10 2 7 The revised CAP states that the progress of Phase II will be
monitored in part through an assessment that nitrate concentrations are generally stable or
declming (disregarding short term fluctuations) or are not generally increasing within the
plume However cntena for assessing whether the nitrate concentrations are stable
declining or generally increasing are not provided Specific statistically based criteria need
to be provided in the CAP to quantify whether the nitrate concentrations are stable declining
or increasing The cntena should account for the potential for short term fluctuations
Provide a detailed description of statistical methods which will be used
21 Table I The newly proposed schedule for constmcting the concrete cover around the
ammonium sulfate tanks does not appear to include any review and approval of the analytical
data or proposed cover area by DRC pnor to constmction of the cover The proposed
schedule must be modified to include such review and approval
[End of comments]
Page 4 of 4 URS
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Total Postage 8 QRQ Review Comments / TR
David 0 Frydenlund
Denison Mines (USA) Corp
1050 17th Street Suite 950
Denver CO 80265
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