DRC-2012-002645 - 0901a068803456b3

Department of
Environmental Quality
Amanda Smith
Executive Director
DIVISION OF RADIATION CONTROL
Rusty Lundberg
Direclor
State of Utah
GARY R HERBERT
Governor
GREG BELL
Lieutenant Governor
December 12, 2012
CERTIFIED MAIL
(Return Receipt Requested)
Jo Ann Tischler, Director, Compliance
Energy Fuels Resources (USA) Inc
225 Umon Boulevard, Suite 600
Lakewood, CO 80228
CO
vr
TU DP
a o o
a
CO
J]
ri
rr 1 o o
U.S. Postal Service™
CERTIFIED MAIL™ RECEIPT
(Domestic Mail Only; No Insurance Coverage Provided)
For delivery mformation visit our website at www.usDS.comm
0 F F 1 C i AL USE 1
Postage
Certified Fee
Retum RecelDt Fee
$
Postmark
Postage
Certified Fee
Retum RecelDt Fee Postmark
Postage
Certified Fee
Retum RecelDt Fee Postmark
re 12/12/12,Signed corrective action plan / TR
JO ANN TISCHLER
ENERGY FUELS RESOURCES (USA) INC
225 UNION BLVD , STE 600
LAKEWOOKCO 80228
PS Form 3100. August 2006 See Reverse for Instructions
Subject Signed and Executed Stipulation and Consent Order Docket No UGWl 2-04, Regarding
Approval and Stipulations for the Energy Fuels Resources (USA) hic May 7, 2012 Corrective
Action Plan for Nitrate, White Mesa Uranium Mill
Dear Ms Tischler
A copy of the fmal and executed Utah Department of Environmental Quality Stipulation and Consent
Order, Docket Number UGWl 2-04 (SCO) is enclosed This SCO approves the Energy Fuels Resources
(USA) Inc May 7, 2012 Corrective Action Plan for Nitrate at the White Mesa Uranium Mill according to
conditions, stipulated penalties and timelines outlined therein
If you have any questions or concems regarding this transmittal please contact Phil Goble or Tom Rushing
at [phone]
Sincerely,
i^^^ DRC.2012-0U2645
Director
RLTRtr
Enclosure Executed Stipulation and Consent Order Docket Number UGW 12-04
F \Energy FuelsNNitrate Corrective Action PlanNFinal SCO UGW12-04\SCO Docket UGWl2-04 Transmittal Ltr docx
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 (80^) 536-4414
www deq utah gov
Pnnted on 100% recycled paper
UTAH DEPARTMENT OF ENVIRONMENTAL QUALITY
IN THE MATTER OF
Energy Fuels Resources (USA) Inc.
225 Union Blvd., Suite 600
Lakewood, CO 80228
STIPULATION AND CONSENT ORDER
DOCKET No. UGW12-04
A. STATUTORY AUTHORITY
This STIPULATION AND CONSENT ORDER (ORDER) is issued to Energy Fuels Resources
(USA) Inc (EFR) facility, by the Director of the Utah Division of Radiation Control' (DIRECTOR)
under the Utah Water Quality Act, Utah Code Ann §§ 19-5-101 to 19-5-123 (ACT), including sections
19-5-104, -106, -111 and -115 This ORDER is also issued in accordance with the Utah Administrative
Procedures Act, Utah Code Ann §§ 63G4-101 to 63G-4-601 and Administrative Procedure Rules, Utah
Admm Code (UAC) R305-6
Under the Water Quality Act, Utah Code Title 19, Chapter 5, "Director" for purposes of groundwater
quality at a facility licensed by and under the junsdiction of the Division of Radiation Control, means the
Director of the Division of Radiation Control Utah Code Ann § 19-5-102(6)
The DIRECTOR may enforce rules made by the Water Quality Board through the issuance of orders m
accordance with Utah Code Ann § 19-5-106(2)(d)
B. APPLICABLE STATUTORY AND REGULATORY PROVISIONS
Utah Code Ann § 19-5-107(l)(a) requires that "Except as provided in this chapter or rules made
under it, it is unlawful for any person to discharge a pollutant into waters of the state or to cause
pollution which constitutes a menace to public health and welfare, or is harmful to wildlife, fish or
aquatic life or impairs domestic, agncultural, industnal, recreational, or other beneficial uses of water,
or to place or cause to be placed any wastes m a location where there is probable cause to believe it
will cause pollution"
Utah Admin Code R317-6-6 15 Corrective Action - outlines the requirements for demonstration to
the DIRECTOR that a corrective action plan meets completeness and accuracy requirements, is
protective of the public health and environment, meets all corrective action concentration limits
specified by Utah Ground Water Quality Standards or altemate Corrective Action Concentration
Limits, and that the corrective action produces a permanent effect
The DIRECTOR and EFR entered into a Stipulated Consent Agreement (SCA),
Docket Number UGW09-03-A which was duly executed on September 30, 2011 The Stipulated
Consent Agreement included a requirement that EFR submit a Nitrate Contamination Corrective
Action Plan (CAP) for DIRECTOR approval on or before November 30, 2011 The CAP was
required to meet all conditions of the SCA and Utah Admm Code cited therein (including R317-6-
6 15) to remediate (retum to compliance) ground water contaminated with mtrate at concentrations
above Utah Ground Water Quality Standards at the White Mesa Uranium Mill The Stipulated
Consent Agreement additionally required updates to the White Mesa Mill Surety Development of
the Corrective Action Plan was required to be implemented in Phases as follows
Effective May 8, 2012 and in accordance with Utah Code Ann § 19-1-105 the title "Executive Secretary" was
Page 1
changed to "Division Director "
Docket No UGWl 2-04
a) Phase I - to include mtrate source control for potential ground water contamination from
ammonia (as N) and mtrate contaminated soil m the vicimty of the Ammonium Sulfate
Crystal Tanks at the White Mesa Uranium Mill,
b) Phase II - to include near term active remediation of the ground water mtrate
contamination by development, implementation, operation and monitonng requirements
for a pumping well network designed to contain and hydraulically control the nitrate
ground water plume to maintain concentrations at or below the Utah Groundwater
Quality Standard of 10 mg/L
c) Phase III - if it has not been demonstrated to the satisfaction of the DIRECTOR that
Phase II has retumed or will retum groundwater nitrate concentrations to the Utah
Groundwater Quality Standard within five (5) years, to include a comprehensive long
term solution for the ground water nitrate contamination based on an i) evaluation of the
continuation of Phases I and II activities alone or in combination with monitored natural
attenuation, and as necessary, ii) an evaluation of additional remediation and monitonng
technologies and techniques, determination of any additional hydrogeologic
charactenzation, groundwater contaminant travel times and directions, determination of
ultimate points of exposure to the public and/or wildlife, appropnate nsk analysis, cost
benefit analysis, and possible development of a petition to the DIRECTOR for altemate
conective action concentration limits pursuant to Utah Admin Code R317-6-615(G)
The Stipulated Consent Agreement specified that Phase III of the CAP will not be
determined at the outset, but may be proposed by EFR at a later date, after enough data
had been collected to evaluate the effectiveness of Phase II
C. FINDINGS OF FACT
1 EFR receives and processes natural uramum-bearmg ores including certain specified altemate feed
matenals, and possesses byproduct matenal in the form of uramum waste tailings and other uranium
byproduct waste generated by the licensee's milling operations This facility is located approximately
6 miles south of Blandmg, Utah on White Mesa m Sections 28, 29, 32, and 33, Township 37 South,
Range 22 East, Salt Lake Baseline and Mendian, San Juan County, Utah (White Mesa Uramum
Mill)
2 On January 27, 2009, the DIRECTOR and EFR entered into a 2009 Stipulated Consent Agreement
(2009 SCA), Docket No UGW09-03 regarding Nitrate Contaminant Investigation activities for the
ground water beneath and in the vicimty of the White Mesa Uramum Mill Part of which set forth the
following requirements
a) EFR was required to submit a wntten Contaminant Investigation Report (CIR) for the
DIRECTOR to review and approve Among other things the CIR was to charactenze the
source(s), physical extent, transfer mechanisms and charactenstics of Nitrate contamination
of the shallow aquifer at the White Mesa Mill, and
b) If determined by the DIRECTOR that a Conective Action Plan (CAP) were required to
address and resolve the Nitrate contamination, EFR would then enter into a new SCA which
would require submittal of a CAP, for DIRECTOR review and approval Said CAP would
be required to set forth required performance standards and an implementation schedule for
groundwater conective actions
3 Pursuant to Item 6 A of the 2009 SCA, EFR submitted a CIR to the DIRECTOR. The CIR, dated
Docket No UGW 12-04 Page 2
December 30, 2009, and entitled "Nitrate Contamination hivestigation Report White Mesa Uranium
Mill Site Blanding, Utah" (2009 CIR) had been prepared by their consultant INTERA, INC
4 On October 5,2010, the DIRECTOR issued a Notice of Additional Required Action (NARA) letter
that notified EFR of the DIRECTOR'S determination that the 2009 CIR was incomplete and that, as
a result of this determination, under Item 7 C of the 2009 SCA, EFR was to remedy the omissions in
the 2009 CIR
5 On December 20, 2010, EFR and the DIRECTOR entered into a Tolling Agreement (Tolling
Agreement Rev 0) to defer any monetary penalties that might accme under the 2009 SCA, and
^provide a time period (Tolling Period) for completion of the additional items required by the NARA
6 Pursuant to the Tolling Agreement (Rev 0), EFR submitted a Plan and Schedule on Febmary 14,
2011 and a revised Plan and Schedule on Febmary 18, 2011, and by agreement of both parties, the
DIRECTOR provided his comments on the revised Plan and Schedule on March 21, 2011
7 In an Apnl 20, 2011 meetmg, EFR and the DIRECTOR agreed that the Plan and Schedule to
conduct additional nitrate mvestigations would be composed of at least four (4) and possibly five (5)
phases of study, including
a) Phase 1A through C - including geoprobe dnlling, and soil sampling / analysis of soils to
investigate
a) Possible natural mtrate salt reservoir in the vadose zone (Phase 1 A),
b) Potential mtrate sources in the mill site area (Phase IB), and
c) Other potential nitrate sources (Phase IC)
b) Phase 2 - including groundwater quality sampling and analysis of existing monitonng wells
for non-isotopic analytes
c) Phase 3 - including deep bedrock core sampling / analysis of possible nitrate reservoir and
nitrate source locations, with similar objectives as Phases 1A through C
d) Phase 4 - including stable isotopic sampling / analysis of groundwater in existing monitoring
wells Details of this investigation were to be determined at a later date, and approved by
both parties
e) Phase 5 - including stable isotopic sampling / analysis of soil/core samples, if needed
8 On Apnl 28, 2011, EFR and the DIRECTOR entered mto a new Revised Tolling Agreement
(Tolling Agreement Rev 1), to extend the Tolling Penod through June 30, 2011 and adopt the
agreements made in the April 20, 2011 meeting Under the Tolling Agreement (Rev 1), EFR agreed
to submit a Revised Phase 1 (A through C) Work Plan on or before May 6, 2011 and a Revised Phase
2 through 5 Work Plan and Schedule on or before June 3, 2011
9 Pursuant to the Tolling Agreement (Rev 1), on May 6, 2011, EFR submitted a Revised Phase 1 (A
through C) Work Plan and Schedule for the Phase 1 A - C investigation prepared by INTERA, for
DIRECTOR review
10 On May 11, 2011, the Utah Division of Radiation Control (DRC) e-mailed comments to EFR on the
May 6, 2011 Revised Phase 1 (A through C) Work Plan and Schedule for the Phase 1 A - C, which
included a May 11, 2011 URS memorandum, and requested that EFR resolve all DRC comments
Docket No UGWl2-04 Page 3
before initiation of field activities
11 All comments were resolved, and EFR conducted field and laboratory work for the Phase 1A-C study
in May and June, 2011
12 Pursuant to the Tolling Agreement (Rev 1), EFR submitted a June 3, 2011 Revised Phase 2 through
5 Work Plan and Schedule (Phase 2-5 Work Plan), prepared by INTERA, for DIRECTOR review
13 In a letter dated June 23, 2011 the DRC provided comments on the June 3, 2011 EFR document in
the form of a URS memorandum, dated June 23, 2011 The DIRECTOR advised EFR that m order
to revise the 2009 SCA.to incorporate the deliverables and timelines set out in an Phase 2 through 5
Work Plan, it would be necessary to provide a level of detail in revisions of that Work Plan for Phases
2, 3,4, and 5 comparable to the level of detail for Phase 1 contained in Attachment 1 of the Tolling
Agreement (Rev 1)
14 On June 30, 2011, EFR and the DIRECTOR entered into a Revised Tolling Agreement [Tolling
Agreement (Rev 2)] to extend the Tolling Period to August 31, 2011, to allow time to revise the
Phase 2 through 5 Work Plan to provide the level of detail required to constmct a replacement SCA
15 Pursuant to the Tolling Agreement (Rev 2), EFR submitted a separate July 1, 2011 detailed Work
Plan and Quality Assurance Plan ("QAP") for the Phase 2 investigation only (Phase 2 Plan, Revision
0) DIRECTOR comments on this document were provided in a July 7, 2011 DRC letter to EFR
16 Pursuant to the Tolling Agreement (Rev 2), EFR provided a revised July 12, 2011 Phase 2 QAP and
Work Plan (Phase 2, Revision 1 0) DRC conditionally approved this document m a letter dated July
18, 2011
17 On August 1 and 2, 2011 EFR submitted preliminary laboratory results for the Phase 1 A-C study to
the DIRECTOR by email
18 Pursuant to the Tolling Agreement (Rev 2), on August 4, 2011, EFR provided a revision to the Phase
2-5 Work Plan (Phase 2-5 Work Plan, Revision 1 0), prepared by INTERA, for DIRECTOR
review
19 On August 11, 2011, in a conference call and email which included an August 11,2011 URS
memorandum (August 11,2011 URS Memo) the DRC commented on the Phase 2-5 Work Plan,
Revision 1 0 and on the August 1, 2011 preliminary laboratory results for the Phase 1 A-C study
20 In accordance with the Tolling Agreement (Rev 2) on August 18, 2011, EFR submitted a revised
Phase 2-5 Work Plan (Phase 2-5 Work Plan, Revision 2 0) for DIRECTOR review, m response to
the DRC comments provided to EFR on August 11, 2011
21 hi a DRC letter dated August 25, 2011, the DIRECTOR advised that
a) after review of the Phase 2-5 Work Plan, Revision 2 0, the DIRECTOR determmed that a
finalized Plan and Schedule, that meets the satisfaction of the DIRECTOR, and which would
allow the preparation of a replacement SCA, is not possible at this time,
b) based on the multiple deficiencies m the Phase 2-5 Work Plan, Revision 2 0, the development
of a replacement SCA for continued contaminant investigation activities is not supported, and
Docket No UGW12-04 Page 4
c) based on the August 1, 2011 EFR preliminary results of Phases 1A through 1C, it would be
extremely difficult for EFR to demonstrate that the White Mesa Mill Site had not caused at
least part of the contamination found m the nitrate and chloride plume(s) beneath the mill
22 On August 29, 2011, EFR and DRC representatives met to discuss the DIRECTOR'S August 25,
2011 findings related to the Phase 2-5 Work Plan Rev 2 0, and the approach forward At the meetmg
the parties agreed to the following
a) After over two years of investigation it was determined that site conditions make it
difficult to determine the total number, locations, magnitude of contnbution, and
proportion of the vanous potential mtrate and chlonde source(s),
b) As a result, resources will be better spent in developing a CAP in accordance with R317-
6-6 15(D), rather than continuing with further investigations as to the source(s) of the
contamination, '
c) The DIRECTOR and EFR agreed that activities related to the White Mesa Nitrate CIR
would cease and that conclusions regarding the causation and attnbution of mtrate and
^chlonde ground water contamination source(s) would be left undetermined
d) The DIRECTOR determined that a CAP was required at the EFR White Mesa facility,
pursuant to UAC R317-6-6 15(C)(1),
e) EFR agreed to develop and implement a CAP after receiving DIRECTOR approval
23 On August 21, 2011, EFR and the DIRECTOR entered into a Tolling Agreement (Tolling
Agreement Rev 3) to defer any monetary penalties that might accme under the 2009 SCA, and
provide a time penod (Tolling Period) for completion and execution of a replacement Stipulated
Consent Agreement (requinng EFR to prepare and submit a Conective Action Plan) on or before
September 30,2011
24 On September 30, 2011, the DIRECTOR and EFR entered into a Stipulated Consent Agreement,
Docket Number UGW09-03-A The SCA included a requirement for EFR to submit a Nitrate
Contamination Conective Action Plan (CAP) for DIRECTOR approval on or before November 30,
2011 The CAP was required to meet all conditions of the SCA and the Utah Administrative Code
cited therein to address ground water contaminated with nitrate (at concentrations above Utah Ground
Water Quality Standards) at the White Mesa Uramum Mill
25 On November 30, 2011, EFR submitted a Nitrate CAP for DIRECTOR review and approval in
accordance with the SCA UGW09-03-A
26 The DIRECTOR sent a January 19, 2012 URS Memorandum and cover letter to EFR commenting
and requinng additional information on the November 30, 2011 CAP EFR and the DRC agreed that
a revised CAP which addressed the additional information requirements would be submitted to the
• DIRECTOR on or before Febmary 27, 2012
27 EFR submitted a Revised Nitrate CAP to the DIRECTOR for review and approval, dated Febmary
27, 2012
28 The DIRECTOR sent a March 19, 2012 URS Memorandum and cover letter to EFR commenting
and requinng additional information on the Febmary 27, 2012 CAP EFR and the DRC agreed that a
revised CAP which addressed the additional information requirements would be submitted to the
DIRECTOR on or before May 7, 2012
29 On May 7, 2012 EFR submitted a revised Nitrate CAP to the DIRECTOR for review and approval
Docket No UGWl2-04 Page 5
Based on DRC and URS review of the revised CAP it was determined that it appeared to address the
additional information required m the March 19, 2012 Memorandum and cover letter and that the
May 7, 2012 Nitrate CAP meets the requirements of Stipulated Consent Agreement,
Docket Number UGW09-03-A
D. ORDER
Ll view of the foregoing FINDINGS, and pursuant to Utah Code Annotated §§ 19-5-106(2)(d) and 19-5-
115 EFR IS hereby ordered to
1 Fully implement all elements of the May 7, 2012 White Mesa Uranium Mill Nitrate CAP according
to, but not limited to. Phases and activities, timelines, monitonng frequencies and protocols, reporting
requirements, and objectives outlined therem
2 Five (5) years from the effective date of this ORDER, EFR shall submit a Corrective Action
Comprehensive Monitormg Evaluation (CACME) Report to the Utah Division of Radiation
Control (DRC) that will include
a) An estimate of the rate of mtrate plume remediation (percent mass reduction and
concentration reduction per year) and projected timeline to retum ground water mtrate
concentrations to the Ground Water Quahty Standards using Phase II alone, including
appropnate adjustments to the reclamation surety estimate,
b) Identification of any changes to Phase II to improve effectiveness and accelerate the
restoration timeline, and,
c) Unless it has been determined to the satisfaction of the DIRECTOR that Phase II has
retumed or will retum groundwater mtrate concentrations to the Utah Groundwater
Quality Standard within five (5) years then preparation of a Phase III planning document
includmg a transport assessment, a hazard assessment, and an exposure assessment along
with a conective action assessment including an evaluation of best available remedial
technologies as descnbed m the May 7, ,2012 CAP Section 7 3
In order to comply with the requirements of UAC R317-6-6 15(D)(3) and R317-6-6 15(E), the
performance evaluation must be certified by a Utah licensed Professional Engineer or Geologist, and
will be exposed to public notice and comment before DIRECTOR approval
3 Submit a revised Reclamation Plan and financial surety cost estimate for DIRECTOR review and
approval as required in Stipulated Consent Agreement Docket No UGW09-03-A, Part 11 E
E. STIPULATED PENALTIES
In the event that EFR fails to provide the required information m accordance with timelines outlined in
the May 7, 2012 White Mesa Uramum Mill Nitrate CAP, or Stipulated Consent Agreement Docket No
UGW09-03-A, then EFR agrees to pay stipulated daily penalties upon written determination by the
DIRECTOR as follows
1 If EFR fails to provide the DIRECTOR at least 14 calendar day notice pnor to undertabng the
following field activities, imtial soil samplmg, mitial ground water pump installations, imtial constmction
of the ammomum sulfate area cover, and imtiation of well abandonment activities, related to Phase I and
Phase II of the May 7, 2012 White Mesa Uramum Mill Nitrate CAP, then EFR agrees to pay stipulated
Docket No UGWl2-04 Page 6
penalties m the amount of $2,000 per calendar day, pursuant to Utah Admin Code R317-1-8-8 3,
Category C
2 If EFR fails to comply with the May 7,2012 White Mesa Uramum Mill CAP Quality Control
requirements and/or the cunently approved White Mesa Uramum Mill Ground Water Monitonng
Quality Assurance Plan for collection and analysis of soil and water samples, then EFR agrees to pay
stipulated penalties in the amount of $500 per calendar day, pursuant to Utah Admin Code R317-1 -8-
8 3, Category D
3 If EFR fails to provide quarterly reports as outlmed m Part 10 2 6 of the May 7,2012 White Mesa
Uramum Mill Nitrate CAP on or before 60 calendar days followmg the momtonng quarter, pursuant to
momtonng reporting timelmes mcluded in the White Mesa Mill Ground Water Discharge Permit, then
EFR agrees to pay stipulated penalties in the amount of $500 per calendar day, pursuant to Utah Admm
Code R317-1-8-8 3, Category D
4 If EFR fails to meet any mandatory performance cntena outlmed m the May 7, 2012 White Mesa
Uramum Mill Nitrate CAP, then EFR agrees to pay stipulated penalties m the amount of $500 per
calendar day, pursuant to Utah Admin Code R317-1 -8-8 3, Category D
5 If EFR fails to perform Phase I imtial soil sampling withm 30 days of the effective date of this ORDER
or such other date as approved by the DIRECTOR, then EFR agrees to pay stipulated penalties in the
amount of $500 per calendar day, pursuant to Utah Admm Code R317-1 -8-8 3, Category D
6 If EFR fails to submit analytical data and a proposed Phase I cover design for the Ammomum Sulfate
Crystal Tank source area for DIRECTOR review and approval within 60 days of EFR receipt of all
Phase I soil sampling data results, then EFR agrees to pay stipulated penalties m the amount of $500 per
calendar day, pursuant to Utah Admm Code R317-1-8-8 3, Category D
7 If EFR fails to constmct the Ammomum Crystal Tank source area cover withm 60 days of design
approval by the DIRECTOR or such other schedule as approved by the DIRECTOR then EFR agrees
to pay stipulated penalties m the amoimt of $2,000 per calendar day, pursuant to Utah Admm Code
R317-1-8-8 3, Category C
8 If EFR fails to submit Discharge Mmimization Technology Plan revisions with concrete pad mamtenance
and mspection requirements to the DIRECTOR on or before 45 days of the effective date of this
ORDER, then EFR agrees to pay stipulated penalties m the amount of $500 per calendar day, pursuant
to Utah Admm Code R317-1 -8-8 3, Category D
9 If EFR fails to begin pumping wells TW4-22, TW4-24, TW4-25 and TWN-2 on or before 45 days after
the effective date of this ORDER, then EFR agrees to pay stipulated penalties m the amoimt of $500 per
calendar day, pursuant to Utah Admm Code R317-1-8-8 3, Category D
10 If EFR fails to submit a detailed Corrective Action Comprehensive Momtonng Evaluation
(CACME) Report of the Phase n Nitrate CAP data and Phase IE evaluation (5) years from the effective
date of this ORDER, includmg but not limited to
a) An estimate of the rate of mtrate plume remediation (percent mass reduction and
concentration reduction per year) and projected timelme to retum ground water mtrate
concentrations to the Ground Water Quality Standards usmg Phase n alone including
appropnate adjustments to the reclamation surety estimate,
b) Identification of changes to Phase n to improve effectiveness and accelerate the restoration
Docket No UGW12-04 Page 7
timelme, and,
c) Preparation of a Phase III planmng document, mcludmg, if required, a transport assessment,
a hazard assessment, and an exposure assessment along with a corrective action assessment
includmg an evaluation of best available remedial technologies as descnbed m the May 7,
2012 CAP Section 7 3,
then EFR agrees to pay stipulated penalties m the amount of $2,000 per calendar day, pursuant to Utah
Admm Code R317-1-8-8 3, Category C
11 If EFR fails to submit the revised surety cost estimate, m compliance with Part 11 E of Stipulated
Consent Agreement Docket UGW09-03-A and the May 7, 2012 White Mesa Uramum Mill Nitrate CAP
Table 1, on or before 60 days from the effective date of this ORDER, then EFR agrees to pay stipulated
penalties m the amount of $2,000 per calendar day, pursuant to Utah Admm Code R317-1 -8-8 3,
Category C
12 If EFR fails to submit evidence of adequate surety for Phase I and n of the White Mesa Mill Nitrate CAP
within 30 days of DIRECTOR approval of the Phase I and II revised surety cost estimate, then EFR will
pay stipulated penalties in the amount of $2,000 per calendar day, pursuant to Utah Admin Code R317-
1-8-8 3, Category C
EFR agrees to pay any required penalties in the form of a check, within 30 calendar days of wntten
notice from the DIRECTOR, made payable to the State of Utah, and delivered or mailed to
Division of Radiation Control,
Utah Department of Environmental Quality
PO Box 144850
168 North 1950 West
Salt Lake City Utah, 84114-4850
F. NOTICE
Compliance with the provisions of this ORDER is mandatory Providing false information may subject
EFR to further civil penalties or cnminal fines
UCA § 19-5-115 provides that a violation'of the ACT or a related order may be subject to a civil penalty
of up to $ 10,000 per day of violation Under certain circumstances of willfulness or gross negligence,
violators may be fined up to $25,000 per day of violation
Signed this l"2r^ day of December, 2012
UTAH DIVISION OF RADIATION CONTROL
Rusty Lundl
Director
Docket No UGWl 2-04 Page 8
ATTACHMENT 1
May 7,2012 Denison Mmes (USA) Corp
Nitrate Ground Water Corrective Action Plan
For the White Mesa Uranium Recovery Facility
Blandmg, Utah
CORRECTIVE ACTION PLAN FOR NITRATE
WHITE MESA URANIUM MILL
NEAR BLANDING, UTAH
May 7, 2012
Prepared for
DENISON MINES (USA) CORP
Independence Plaza, Suite 950
1050 Seventeenth Street
Denver, Colorado 80265
Prepared by
HYDRO GEO CHEM, INC
51 W Wetmore Road, Suite 101
Tucson, Anzona 85705
[phone]
Project Number 7180000 00-7 0
HYDRO GEO CHEM, INC.
^nvifonmental Science (& Technology
CORIUECTIVE ACTION PLAN FOR NITRATE
WHITE MESA URANIUM MILL
NEAR BLANDING, UTAH
Piepaied for.
DENISON MINES (USA) CORP.
Independence Plaza, Suite 950
1050 Seventeenth Stieet
Denvei, Coloiado 80265
Piepaied, Reviewed, and Approved by
tewartJ SmitliU^PG No. 5336166-2250
Associate Hydrogeologist
May 7, 2012
TABLE OF CONTENTS
INTRODUCTION, OVERVIEW, AND SCOPE 1
HISTORY OF NITRATE CONTAMINATION INVESTIGATION . 3
2 1 Summary of Contamination Investigation Report Activities 3
2 2 Conclusions from the Contamination Investigation 6
FRAMEWORK AND OBJECTFS/ES OF THE CAP • 9
3 1 Applicable Regulations and Requirements . . 9
3 2 Objectives of the CAP ... . ... 10
32 1 Summary of Phase I Objectives and Scope .. .10
3 2 2 Summary of Phase II Objectives and Scope. 11
3 2 3 Summary of Phase HI Objectives and Scope . . .. 12
3 3 Preliminary Milestones for the CAP . . 13
BACKGROUND . .... 15
41 Geologic Setting . ..... 15
4 2 Hydrogeologic Setting . .16
4 3 Perched Zone Hydrogeology .. . .... 16
4 3 1 Lithologic and Hydraulic Properties . 17
43 11 Dakota . . .... 18
43 12 Burro Canyon . . 18
4 3 2 Perched Groundwater Flow .. . .... 19
43 3 Saturated Thickness . . . .20
4 4 Summary ... 21
4 5 Nitrate Occurrence . . . . 22
4 5 1 Source Areas . . 22
4 5 2 Nitrate Concentration Trends. . . 24
CHARACTERIZATION OF STUDY AREA ^ • 25
5 1 Extent of Study Area .. . . 25
5 2 Hydrogeology .. ... 26
CORRECTIVE ACTION CONCENTRATION LIMITS . .. 27
CORRECTTVE ACTION PLAN-CONSTRUCTION AND OPERATION . . .29
7 1 Phase I Descnption and Rationale . .. ... 30
7 11 Approximation of the Lateral Extent of ContaminaUon and
Concrete Cover . . . 30
7111 Soil Sampling Program Objective and Design . 31
7 112 Field Activities/Sampling Methods 31
7 113 Sample Handhng and Custody . 32
7 114 Analytical Methods 33
7 115 Quality Control . . 33
Corrective Action Plan for Nitrate
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redline Final 05 07 12 Fnl doc
May 7.2012
TABLE OF CONTENTS (Continued)
7 1 2 Constmction of the Phase I Action 34
7 13 Maintenance of the Phase I Action 34
7 14 Estimation and Removal of Contaminated Soil Dunng /
Mill Reclamation . 35
7 2 Phase II Descnption and Rationale 36
7 2 1 Well Abandonment 41
7 2 2 Groundwater Pumping System . 42
7 2 3 Water Level Momtonng . 43
7 2 4 Water Quality Momtonng . 43
7 25 Reporting ... . " . 44
7 3 Phase m , . . . . 45
7.3 1 Water Level and Water Quality Momtonng .. . 46
8 ASSESSMENT OF CORRECTR^E ACTION AND PROTECTION OF PUBLIC
HEALTH AND THE ENVIRONMENT AND CONTINGENCY PLAN 47
8 1 Stabihtyof Plume Boundary (Phase II) .. 48
8 2 Concentration Trends within the Plume (Phase II) ..48
8 3 Nitrate Mass Removal Rates Resulting from Pumping (Phase IT) 50
8 4 Stability of the Proportion of the Nitrate Plume under
Hydraulic Capture (Phase n) . . 51
8 5 Phase m 51
8 6 Permanent Effect of Corrective Action , 52
8 7 In-Place Contaminant Control ... 52
9 IMPACTS OF OFFSITE ACTIVITIES . . 53
10 PROPOSED PLUME CORRECTIVE ACTION ACTIVITIES 55
10 1 Phase I . 55
10 2 Phase n ... 55
10 2 1 Groundwater Pumpmg . . 55
10 2 2 Water Level Momtonng . 55
10 2 3 Water Quahty Momtonng .... 55
10 2 4 Estimation of Capture Zones ... 56
10 2 5 Estimation of Pumped Nitrate Mass 56
10 2 6 Reporting ... .56
10 2 7 Additional Measures . 56
10 3 Phase m . . 57
11 REFERENCES 59
12. LIMITATIONS STATEMENT . 61
Correcuve Action Plan for Nitrate
White Mesa Uranium Mill Near Blandmg Utah
Revised Nitrate Corrective Action Plan redline Final 05 07 12 Fnl doc
May 7,2012
TABLE OF CONTENTS (Continued)
TABLES
1 Nitrate Corrective Action Schedule
2 Hydraulic Conductivity Estimates for Wells m the Nitrate Plume Area
3 Nitrate Concentrations (mg/L) at Wells within the Nitrate Plume
4 Companson of Chloroform Pumpmg Well Transnussivities to Proposed Nitrate Pumping
Well Transnussivities
FIGURES
1-1 White Mesa Mill Site Plan Showing Locations of Seeps and Spnngs
I- 2 Site Plan Showing Perched Well Locations and 3'^ Quarter, 2011 Nitrate Plume Extent,
White Mesa Site
2 Photograph of the Contact Between the Burro Canyon Formation and the Brushy Basm
Member
3 Kriged Top of Bmshy Basin Elevations, White Mesa Site
4 Knged 3'*^ Quarter, 2011 Water Levels, White Mesa Site
5 3'"^ Quarter, 2011 Saturated Thickness, White Mesa Site
6 3''' Quarter, 2011 Depths to Water, White Mesa Site
7 Knged 3''* Quarter, 2011 Nitrate (mg/L) (NitratQ + Nitrite as N), White Mesa Site
8 Potential Nitrate Source Areas and Geoprobe Locations Showing the Thickness of the
Mancos Shale
9-1 Nitrate Concentrations m MW-30 and MW-31
9-2 Companson of Nitrate Plume Boundanes, 3'"* Quarter, 2010 and 3"^ Quarter, 2011
10 3'"^ Quarter, 2011 Nitrate and Oiloroform Plumes, White Mesa Site
II- 1 Ammonium Sulfate Contamination
11-2A Ammomum Sulfate Tank Area (Current Layout)
11-2B Ammomum Sulfate Concrete Cover (Proposed Location)
11-3 Fire System Schematic
11-4 General Area of Proposed Concrete Cover
11-5 Well Pumping Transfer Lines
12 Estimated Extent of CapUire of Chloroform Pumping Well MW-26, 3''* Quarter, 2011
13 Anticipated Mimmum Downgradient Extent of Capture Resulting from Pumping
TW4-22, TW4-24, TW4-25, and TWN-2
APPENDICES
A Hydrogeologic Cross Sections
B Lithologic Logs for MW-3 A, MW-30, MW-31, MW-34, and MW-37
Corrective Action Plan for Nitrate m
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redline Fmal 05 07 12 Fnl doc
May 7,2012
Corrective Action Plan for Nitrate IV
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Corrective Action Plan redline Final 05 07 12 Fnl doc
May 7,2012
1. INTRODUCTION, OVERVIEW, AND SCOPE
This document presents a Corrective Action Plan (CAP) to address nitrate + mtnte (as mtrate)
(heretofore refened to as "mtrate") contamination in a shallow perched groundwater zone
beneath the White Mesa Uramum Mill (the "site" or the "Mill"), located on White Mesa near
Blanding, Utah, operated by Demson Mines (USA) Corp ("Demson") Figure 1-1 is a map
showing site features including seeps and spnngs at the margins of White Mesa Figure 1-2 is a
map of the site showing the locations of perched zone monitonng wells and the area of the
perched groundwater zone affected by nitrate concentrations exceeding 10 milligrams per liter
(mg/L) that is the focus of this CAP For the purposes of this document, all nitrate concentrations
m groundwater have been expressed as mg/L nitrogen Elevated concentrations of chloride were
also detected m the momtonng wells having elevated concentrations of mtrate In a letter dated
December 1, 2009, the Co-Executive Secretary of the Utah Water Quality Board (the "Executive
Secretary") recommended that Demson also address and explain the elevated chloride
concentrations
Nitrate within the area shown in Figure 1 was first detected m wells TW4-19, TW4-22, TW4-24,
and TW4-25 that were installed as part of the investigation of a chloroform plume discovered at
perched well MW-4 m 1999 Pumping of chloroform-laden perched water began in 2003 (HGC,
2007a) and continues to the present time via pumping of wells MW-4, MW-26, TW4-4, TW4-
19, andTW4-20
Investigation of mtrate exceeding 10 mg/L in the perched water included installation of 19
temporary TWN-senes wells shown m Figure 1 and numerous shallow bonngs as part of a
source investigation Demson identified and pnontized potential sources of the mtrate in the
December 2009 Source Review Report for Nitrate and Chloride in Groundwater at the White
Mesa Mill, (INTERA, 2009a) and in the subsequent August 2011 Nitrate Investigation Revised
Phases 2 through 5 Work Plan (INTERA, 2011)
Based on the investigations, Demson and the Executive Secretary have agreed that the corrective
actions will involve three Phases Phase I will involve source control m the vicimty of the Mill's
ammonium sulfate tanks, the one remaining potential source of contamination Phase II will
involve near term active remediation of the mtrate contamination by pumping contaminated
water into the Mill's tailings cells for disposal, combined with momtored natural attenuation
Phase ni, if necessary, will be at the discretion of Denison and would involve a long tenn
solution for the mtrate contamination, in the event that the continuation of Phase II is not
considered adequate or appropnate Phases I and II are addressed m this CAP and will
commence shortly upon Executive Secretary approval of this CAP Phase III is not covered m
Corrective Action Plan for Nitrate \
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Corrective Action Plan redline Final 05 07 12 Fnl doc
May 7, 2012
detail in this CAP and, if determined to be necessary, will be addressed in a separate CAP
revision
Every reasonable effort will be made to ensure that corrective action implementation effort for
the nitrate plume is performed m a manner that is mutually compatible with, and integrated with,
the corrective action implementation effort for the chloroform plume m terms of scope and
operation to ensure the effects of corrective action operations for the mtrate plume do not impede
or substantially reduce the effectiveness of corrective action operations for the chloroform
plume, and vice versa
The elements of this CAP document include the following items
A History of the Nitrate Contamination Investigation
A discussion of the decision to proceed with Corrective Action
A summary of the applicable requirements
CAP objectives
A descnption of the site hydrogeology
The nature and extent of mtrate m the perched zone
Proposed corrective remedial actions and concentration limits
Proposed corrective action contingencies
Corrective Action Plan for Nitrate
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
2. HISTORY OF NITRATE CONTAMINATION INVESTIGATION
A bnef discussion of the Nitrate Contamination Investigation and the decision to proceed with
corrective action is provided m Sections 2 1 and 2 2
2.1 Summary of Contamination Investigation Report Activities
On January 27, 2009 the Executive Secretary of the Utah Division of Radiation Conti-ol ("DRC")
and Demson entered mto the 2009 Stipulated Consent Agreement ("SCA"), which set forth the
requu-ement that Demson would subrmt a wntten Contaminant Investigation Report (CIR) for
Executive Secretary review and approval, to among other things, charactenze the soiirce(s),
physical extent, transfer mechamsms and charactenstics of the Nitrate contamination of the
shallow aquifer at the site
Denison submitted to the Executive Secretary a CIR which had been prepared by their consultant
INTERA, Inc The CIR was dated December 30, 2009 (INTERA, 2009b) and entitled "Niti-ate
Contamination Investigation Report White Mesa Uranium Mill Site Blanding, Utah" (2009 CIR)
On October 5, 2010 the Executive Secretary issued a Notice of Additional Required Action
(NARA) letter that notified Denison of the Executive Secretary's determination that the 2009
CIR was incomplete
On December 20, 2010 Denison and the Executive Secretary entered into a Tolling Agreement
(Tolling Agreement (Rev. 0)) to defer any monetary penalties that might accme under the 2009
SCA, m order to provide a time penod (Tolling Penod) for
1 Denison to prepare and submit a plan and schedule (Plan and Schedule) by which to
conduct additional mvestigations to resolve open issues identified in the October 5, 2010
NARA on or before Febmary 15, 2011,
2 The Executive Secretary to provide his imtial comments on the Plan and Schedule on or
before March 15, 2011, and for Demson and the Executive Secretary to finalize the Plan
and Schedule, and
3 Demson and the Executive Secretary to negotiate, finalize and execute a revised or
replacement SCA that incorporates the Plan and Schedule
In addition, the Tolling Agreement (Rev 0) requued that the Tolling Penod be extended from
January 4, 2010 (submittal of the 2009 CIR to the Executive Secretary) until Apnl 30, 2011
Pursuant to the Tolling Agreement (Rev 0), Demson submitted a Plan and Schedule on February
14, 2011 and a revised Plan and Schedule on February 18, 2011, and the Executive Secretary
provided his comments on the revised Plan and Schedule on March 21, 2011 In an Apnl 20,
Corrective Action Plan for Nitrate 3
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redline Final 05 07 12 Fnl doc
May 7 2012
2011 meeting, Denison and the Executive Secretary agreed that the Plan and Schedule to conduct
additional nitrate investigations would be composed of at least four (4) and possibly five (5)
phases of study, including
1 Phase lA through C - including geoprobe drilling, and soil sampling/analysis of soils to
investigate
a Possible natural nitrate salt reservoir m the vadose zone beyond the mill site area
(Phase lA),
b Potential niti-ate sources m the null site area (Phase 1 B), and
c Other potential nitrate sources (Phase 1 C)
2 Phase 2 - including groundwater quality samphng and analysis of existing momtonng
wells for non-isotopic analytes
3 Phase 3 - including deep bedrock core sampling/analysis of possible natural mtrate
reservoir and potential mtrate source locations, with similar objectives as Phases 1 A
through C
4 Phase 4 - including stable isotopic sampling/analysis of groundwater in existing
momtonng wells Details of this investigation were to be determined at a later date, and
approved by both parties.
5 Phase 5 - including stable isotopic sampling/analysis of soil/core samples, if needed
On Apnl 28, 2011, Demson and the Executive Secretary entered into a Revised Tolling
Agreement (Tolling Agreement (Rev 1), to extend the Tolling Period through June 30, 2011 and
adopt the agreements made in the Apnl 20, 2011 meeting Under the Tolling Agreement (Rev
1), Demson agreed to submit a Revised Phase 1 (A through C) Work Plan on or before May 6,
2011 and a Revised Phase 2 through 5 Work Plan and Schedule on or before June 3, 2011
Pursuant to the Tolhng Agreement (Rev 1), Denison submitted a May 6, 2011 Revised Phase 1
Work Plan and Schedule for the Phase 1 A - C investigation prepared by INTERA, for Executive
Secretary review On May 11, 2011, the DRC 1) provided via email, comments on the May 6,
2011 INTERA document, and requested that Demson resolve all DRC comments before
imtiation of field activities All comments were resolved, and Demson conducted field and
laboratory work for the Phase 1 A-C study in May and June, 2011
Pursuant to the Tolling Agreement (Rev 1), Demson submitted a June 3, 2011 Revised Phase 2
through 5 Work Plan and Schedule (Phase 2 - 5 Work Plan), prepared by INTERA, for Executive
Secretary review In a letter dated June 23, 2011 DRC provided comments on this Denison
document in the form of a URS memorandum, dated June 23, 2011 and advised Denison that in
order to revise the 2009 SCA to incorporate the deliverables and timelines set out in an
Corrective Action Plan for Nitrate 4
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
approvable Phase 2 through 5 Work Plan, it would be necessary to provide a level of detail in
revisions of that Work Plan for Phases 2, 3, 4, and 5 comparable to the level of detail for Phase 1
contained in Attachment 1 of the Tolling Agreement (Rev 1)
On June 30, 2011, Demson and the Executive Secretary entered into a Revised Tolling
Agreement [Tolhng Agreement (Rev 2)] to extend the Tolling Penod to August 31, 2011, in
order to facilitate the revision of the Phase 2 through 5 Work Plan to provide the level of detail
required to constmct a replacement SCA Pursuant to the Tolhng Agreement (Rev 2), Denison
submitted a separate July 1, 2011 detailed Work Plan and Quahty Assurance Plan ("QAP") for
the Phase 2 investigation (Phase 2 Plan, Revision 0) Executive Secretary comments on this
document were provided m a July 7, 2011 DRC letter Demson provided a revised July 12, 2011
Phase 2 QAP and Work Plan (Phase 2, Revision 1 0), which DRC conditionally approved in a
letter dated July 18, 2011
On August 1 and 2, 2011 Demson submitted by email preliminary laboratory results for the
Phase 1 A-C study to the Executive Secretary.
On August 4, 2011, Demson provided a revision to the Phase 2 - 5 Work Plan (Phase 2-5 Work
Plan, Revision 1 0), prepared by INTERA, for Executive Secretary review DRC comments on
the Phase 2-5 Work Plan, Revision 1 0 and on the August 1, 2011 preliminary laboratory results
for the Phase 1 A-C study, were provided to Demson on August 11, 2011 as part of a conference
call, and a DRC email, which included an August 11, 2011 URS memorandum Under a cover
letter dated August 18, 2011, Demson submitted a revised Phase 2-5 Work Plan (Phase 2-5 Work
Plan, Revision 2 0) for Executive Secretary review, in response to the comments provided to
Denison on August 11, 2011
As discussed in the following Sections, DRC and Demson have agreed to proceed with
corrective action
In an August 25, 2011 DRC letter, the Executive Secretary advised that per review of the Phase
2-5 Work Plan, Revision 2 0, the Executive Secretary has determined that a finalized Plan and
Schedule, that meets the satisfaction of the Executive Secretary, and which would allow the
preparation of a replacement SCA, is not possible at this time; and that the development of a
replacement SCA for continued contanunant investigation activities is not supported
At a meeting between Demson and DRC on August 29, 2011 to discuss the Executive
Secretary's August 25, 2011 findings related to the Phase 2-5 Work Plan Rev 2 0, the
preliminary laboratory results for the Phase I A-C study, and the approach forward, Denison and
DRC agreed that
Corrective Action Plan for Nitrate 5
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Corrective Acuon Plan redhne Final 05 07 12 Fnl doc
May 7, 2012
After more than two years of investigation it has been detenmned that there are site
conditions that make it difficult to determine the source(s) of the contamination at the
White Mesa site.
As a result, resources will be better spent in developing a CAP in accordance with UAC
R317-6-6 15(D), rather than continuing with further investigations as to the source(s) of
the contamination
Dunng discussion throughout October 2011, Denison and the Executive Secretary acknowledged
that It has not been possible to ^ate to deternune the source(s), cause(s), attnbution, magnitudes
of contiibution, and proportion(s) of the local nitrate and chlonde in groundwater, and thereby
cannot eliminate Mill activities as a potential cause, either in full or in part, of the contamination
As a result, Demson and the Executive Secretary agreed that resources will be better spent m
developing a CAP in accordance with UAC R317-6-6 15(D), rather than continuing with further
investigations as to the source(s) and attnbution of the groundwater contamination
2.2 Conclusions from the Contamination Investigation
The contamination investigation program from 2009 to 2011 has provided a basis for
development of a CAP Specifically the investigation has determined
• the areal and spatial extent of the plume,
• that the plume does not appear to be increasing in size or concentration,
• that there are no known unaddressed current or ongoing sources of contamination
As discussed above, a number of potential mill and non-mill sources were identified in (INTERA
(2009a), and INTERA (2011) Based on the investigation and source evaluations, there are no
known current unidentified or unaddressed sources There appear to have been a number of
known and potential histonc sources, however, it has not been possible to confirm or quantify
the contnbution of each
Analytical results indicate that neither the average concentration of the plume nor the areal extent
of the plume have increased dunng the momtored period The only potential current source
identified and potentially requinng control is the ammomum sulfate tanks This potential source
is addressed in Phase I of the CAP, discussed in Sections 3 2 1 and 7 1 below
The Executive Secretary determined that a CAP is required at the White Mesa facility, pursuant
to UAC R317-6-6 15(C)(1) and Demson agreed to develop, secure Executive Secretary approval,
and implement a CAP The Executive Secretary has therefore determined, and Demson agreed to
Corrective Action Plan for Nitrate
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redline Fmal 05 07 12 Fnl doc
May 7, 2012
submit a CAP, pursuant to the requuements of the Utah Ground Water Quality Protection Rules
[UAC R317-6-6 15(C-E)]
The purpose of Phase I of this CAP is to remedy the effects of tiie ammomum sulfate tank
potential source The purpose of each of the proposed phases of this CAP is discussed further m
section 3 2
Corrective Action Plan for Nitrate
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Correcuve Action Plan redline Final 05 07 12 Fnl doc
May 7, 2012
Corrective Action Plan for Nitrate
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redline Fmal 05 07 12 Fnl doc
May 7, 2012
3. FRAMEWORK AND OBJECTIVES OF THE CAP
Applicable regulations and requirements governing the CAP, and preliminary rmlestones are
discussed in Sections 3 1 through 3 3
3.1 Applicable Regulations and Requirements
Demson agreed to subnut a CAP for Executive Secretary review and approval, on or before
November 30, 2011 tiiat meets the CAP related requirements of UAC R317-6-6 15 (D 2, 3 and
E) This document constitutes the "Nitrate CAP"
The remaimng sections of this CAP are intended to demonstrate, per the requirements in UAC
R317 -6-6 15(D)(2) and (3), that
• the proposed action(s) are protective of pubhc health and the environment, including
consideration of future impacts of the nitrate plume on land and water resources not
owned and controlled by Demson
• the corrective action meets the State (jround Water Quality Standards, pursuant to UAC
R317 -6-6 15(F) Altematively, Denison may petition the Utah Water Quality Board for
approval of an Altemate Corrective Action Concentration Limit as part of the CAP,
Phase m, pursuant to UAC R317 -6-6 15(G)
• the action will produce a permanent effect
Per UAC R317 -6-6 15(D)(2) and (3) the action proposed in the CAP is required to meet any
other additional measure required by the Executive Secretary under UAC R317 -6-6 15(E)(5)
Demson has agreed with the Executive Secretary that these additional measures shall include, but
are not limited to
• Remediation guidance found in the Apnl, 2004 EPA Handbook of Groundwater
Protection and Cleanup Policies for RCRA Corrective Action (EPA530-R-04-030) or
equivalent, to the extent applicable, as detenmned by the Executive Secretary,
• Determination of corrective action performance standards, objectives, and cntena for
groundwater remediation systern design, constmction, operations and/or maintenance, as
approved by the Executive Secretary m accordance with applicable regulations,
• Determination of long term operation, maintenance, system performance and
groundwater quahty monitonng requirements to evaluate effectiveness of the approved
corrective action(s), at a frequency, and by methods approved by the Executive Secretary,
• Submittal of wntten quarterly Denison reports of pumping and momtonng well system
performance and groundwater quality momtonng information for Executive Secretary
review and approval In the event that additional information is required of any report,
Denison shall respond to and provide a Plan and Schedule for Executive Secretary
Corrective Action Plan for Nitrate 9
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Corrective Action Plan redline Final 05 07 12 Fnl doc
May 7, 2012
approval to'resolve all issues /concerns within 30 calendar days of receipt of written
Executive Secretary notice.
Timely Denison verbal and wntten notification of process or equipment failures, and
corrective actions taken, or a timely schedule by which corrective action will be taken to
remm the facility to full compliance with CAP performance standards, objectives, and
cntena, and
Penodic Demson review, summation, and report submittal, for Executive Secretary
approval, to demonstrate if the approved corrective action is protective of public health
and the environment The interval of said report period shall not exceed five (5) years
3.2 Objectives of the CAP
The objectives of the CAP are the following
• Mimmize or prevent further downgradient migration of the perched nitrate plume (Figure
1-2) by a combination of pumping and reliance on natural attenuation,
• Prevent mtrate concentrations exceeding the action level from migrating to any potential
point of exposure,
• Momtor to track changes m concentrations withm the plume and to establish whether the
plume boundanes are expanding, contracting, or stable,
• Provide contingency plans to address potential continued expansion of the plume and the
need for additional monitonng and/or pumping points, and
• Ultimately reduce mtrate concentrations at all monitoring locations to the action level or
below
To achieve these objectives, the CAP proposes a phased approach
3 2 1 Summary of Phase I Obiectives and Scope
Per Section 11 A(l) of the SCA, Phase I is required to include a control for the soil contamination
observed at the ammomum sulfate tanks, a potential source of perched groundwater
contamination Pursuant to UAC 317-6-6 15 (E)(4)(b) tins control will include at a mimmum
Determination, to the satisfaction of the Executive Secretary, of the physical extent of the soil
contamination observed at the ammomum sulfate tanks near bonngs GP-25B (Nitrate + Nitnte
(as N) 1,530 mg/kg-dry at depth of 6 feet) and GP-26B (Ammoma (as N) 1,590 mg/kg-dry at a
depth of 16 feet) that were part of the nitrate investigation Such effort shall mclude an estimate
of the volume (the "Contaminated Soil Volume") of the contaminated soils down to but not
including bedrock, and an estimate of the surface area (the "Contaminated Surface Area") at or
above the estimated location of the Contaminated Soil Volume, and either a Plan and Schedule,
Corrective Action Plan for Nitrate 10
White Mesa Uramum Mill Near Blandmg, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7,2012
to be submitted on or before January 1, 2012, for Executive Secretary approval, to cover the
Contaminated Surface Area with at least six inches of concrete, to the extent not already covered
by concrete or existing buildings, to prevent mfiltiration of surface water into the contaminated
soils, and/or a Plan and Schedule, to be submitted on or before January 1, 2012, for Executive
Secretary approval, to remove the Contaminated Soil Volume and dispose of the contaminated
soils m the Mill's tailings impoundments If Demson chooses to cover the Contaminated Surface
Area with concrete, Demson must remove the Contaminated Soil Volume at a later date pnor to
site closeout and must submit a revised surety estimate on or before March 4, 2012 to include
future costs to remove the Contaminated Soil Volume
As discussed in Section 7 1 of this CAP, Demson proposes to constmct a sloped and drained
concrete pad of six inches in depth over an area covenng the lateral extent of contaimnation to be
determined as discussed in Section 7 1 Denison also proposes a future removal of contaminated
soil at the time of Mill site reclamation and, for conservatism, proposes to revise the reclamation
surety estimate to mclude a volume of soil to be removed and placed in the tailings area of twice
the volume of contaminated soil identified m the contaimnation investigation Further details are
discussed in Section 7 1, below
3 2 2 Summarv of Phase II Obiectives and Scope '
Per Section 11 A(2) of the SCA, Phase II is to mclude near term active remediation of the nitrate
contamination by pumping contaminated water mto the Mill's tailings cells for disposal Said
phase shall also include 1) the development, implementation, operation, and momtonng
requirements for a pumping well network designed to contain and hydraulically control the
mtrate groundwater plume to maintain concentrations at or below the Utah Groundwater Quality
Standard (10 mg/L), i e, prevent physical expansion of said plume, and 2) monitonng of
chloride concentrations
Phase II constitutes an intenm remedial action that consists of a combination of "active" and
"passive" strategies The active strategy consists of removing mtrate mass as rapidly as practical
by pumping areas within the plume that have high mtrate concentrations and relatively high
productivity Continued momtonng within and outside the plume is considered part of the active
strategy The passive strategy consists of relying on natural attenuation processes to reduce
mtrate concentrations Reductions m concentrations would be achieved by physical processes
such as hydrodynamic dispersion, and dilution via mixing with recharge and waters outside the
plume
Natural attenuation is expected to reduce mtrate concentrations withm the entire plume
However, withm upgradient portions of the plume that have the highest concentrations, direct
Corrective Action Plan for Nitrate | ]
White Mesa Uramum Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
mass removal via pumping will be the primary means to reduce concentrations In downgradient
portions of the plume where concentrations are lower, natural attenuation will be a more
important mechanism m reducing concentrations
3 2 3 Summarv of Phase III Obiectives and Scope
Per the SCA, Phase III, if necessary is to include a comprehensive long term solution for the
mtrate groundwater contamination at the Mill Site This phase will be undertaken at a later date
only after pubhc participation and Executive Secretary approval Phase III may include, but is
not limited to continuation of Phases I and n activities alone or m combination with monitored
natural attenuation, evaluation of additional remediation and momtonng technologies/techniques,
determination of any additional hydrogeologic charactenzation, groundwater contaminant travel
times and directions, determination of ultimate points of exposure to the public and/or wildlife,
appropnate nsk analysis, a cost/benefit analysis, and the possible development of and petition to
the Board for altemate corrective action concentration limits pursuant to UAC R317 -6-6 15 (G)
This CAP does not specify the details of Phase IH, at this time A Phase III preliminary plan and
schedule for the evaluation of alternatives, for the completion of any further smdies, analyses,
applications and petitions, and for the ultimate definition of Phase III, may be proposed by
Denison at a later date, after completion of such studies and evaluations, followed by submittal
of a proposed CAP revision to the Executive Secretary Until such time, the activities of the
Phase I and Phase II remediation will continue as stipulated in the approved CAP
The CAP IS not intended to address contamination located outside the Mill's restncted area and
that IS not contiguous with groundwater contamination inside the Mill's restncted area The CAP
will therefore evaluate which of the existing momtonng wells will be maintained and which
wells (including certain upgradient and off-site wells) can be abandoned, subject to pnor
Executive Secretary approval
It should be noted that while Phase II of the CAP requires monitonng of chlonde concentrations,
the CAP does not explicitly identify measures for controlling chlonde levels per se, because
there is no health standard for chlonde in groundwater However, as discussed and agreed to
with DRC dunng meetings in October 2011, chlonde appears to be co-located with mtrate m
groundwater at the Mill and hydrogeological measures to contain nitrate will also contain
chlonde
Corrective Action Plan for Nitrate 12
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
3.3 Preliminary Milestones for the CAP
Per the SCA, Demson has committed to the following milestones for corrective action Dates for
the following nulestones will be estabhshed based on the date of the Executive Secretary's
approval of the CAP and issuance of a Consent Order approving the CAP
• Within 30 calendar days of the Executive Secretary's approval of tiie CAP, pursuant to
UAC R317-6-6 15(E), Denison shall commence implementation and execution of all
corrective actions required under a future Consent Order to be issued by the Executive
Secretary that addressed the approved CAP A proposed schedule for implementation of
tiie CAP IS included as Table 1 to tius CAP
• Withm 60 calendar days of the Executive Secretary's issuance of a future Consent Order
regarding tiie approved CAP, pursuant to UAC R317-6-6 15(E), Demson will submit a
revised Reclamation Plan and financial surety cost estimate (Revised Surety), for
Executive Secretary review and approval which addresses the groundwater corrective
action, with the surety sufficient to recover the anticipated cost and time frame for
achieving compliance, before the land is transferred to the federal government for long-
term custody At a immmum, the Denison surety will provide for all costs for Phases I
and II of the approved CAP for a penod of time until Executive Secretary approval of
Phase ni of tiie CAP to restore groundwater to tiie established site specific groundwater
cleanup standards pursuant to UAC R317-6-6 15 before the site is transferred to the
federal government for long term custody
Corrective Action Plan for Nitrate 13
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7,2012
Corrective Action Plan for Nitrate 14
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
4. BACKGROUND
Sections 3 1 through 3 4 provide a bnef descnption of site hydrogeology that is based pnmanly
on TITAN (1994), but includes the results of more recent site investigations Section 3 5
discusses the occurrence of nitrate m the perched water at the site and focuses on the mtrate
plume shown in Figure 1-2 J
4.1 Geologic Setting ^
The Mill IS located within the Blanding Basm of the Colorado Plateau physiographic province
Typical of large portions of the Colorado Plateau province, the rocks underlying the site are
relatively undeformed. The average elevation of the site is approximately 5,600 feet above mean
sea level ('Tt amsl")
The site is underlain by unconsohdated alluvium and indurated sedimentary rocks consisting
pnmanly of sandstone and shale The indurated rocks are relatively flat lying with dips generally
less than 3° The alluvial matenals consist mostly of aeolian silts* and fine-grained aeohan sands
with a thickness varying from a few feet to as much as 25 to 30 feet across the site The alluvium
IS underlain by the Dakota Sandstone and Burro Canyon Formation, which are sandstones having
a total thickness ranging from approximately 100 to 140 feet In portions of the site, a few feet to
as much as about 30 feet of Mancos Shale lies between the alluvium and the Dakota Sandstone -
Beneath the Burro Canyon Formation lies the Momson Formation, consisting, m descending
order, of the Brushy Basm Member, the Westwater Canyon Member, tiie Recapture Member,
and the Salt Wash Member Figure 2 is a photograph of the contact between the Burro Canyon
Formation and the underlying Bmshy Basin Member taken from a location along highway 95
immediately north of the Mill This photograph illustrates the transition from the cliff-fomung
sandstone of the Burro Canyon Formation to the slope-forming Bmshy Basm Member
The Bmshy Basm and Recapmre Members of the Momson Formation, classified as shales, are
very fine-grained and have a very low hydraulic conductivity The Bmshy Basm Member is
pnmanly composed of bentomtic mudstones, siltstones, and claystones The Westwater Canyon
and Salt Wash Members also have a low average vertical hydraulic conductivity due to the
presence of mterbedded shales
Beneath the Momson Formation he the Summerville Formation, an argillaceous sandstone with
mterbedded shales, and tiie iEntrada Sandstone Beneath the Entrada lies the Navajo Sandstone
The Navajo and Entrada Sandstones constitute the primary aquifer m the area of the site The
Entrada and Navajo Sandstones are separated from the Buno Canyon Formation by
Corrective Action Plan for Nitrate \ 5
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl^doc
May 7, 2012
approximately 1,000 to 1,100 feet of matenals having a low average vertical hydraulic
conductivity Groundwater within tins system is under artesian pressure in the vicimty of the site,
IS of generally good quality, and is used as a secondary source of water at the site
4.2 Hydrogeologic Setting
The site is located withm a region that has a dry to and continental climate, with an average
annual precipitation of approximately 13 3 inches, and an average annual lake evaporation rate
of approximately 47 6 inches Recharge to the pnncipal aquifers occurs mainly along the
mountain fronts (for example, the Henry, Abajo, and La Sal Mountains), and along the flanks of
folds such as Comb Ridge Monocline
Although the water quality and productivity of the Navajo/Entrada aqmfer are generally good,
the depth of the aquifer (approximately 1,200 feet below land surface [ft bis]) makes access
difficult The Navajo/Entrada aquifer is capable of yielding sigmficant quantities of water to
wells (hundreds of gallons per minute ["gpm"]) Water m wells completed across these units at
the site rises approximately 800 feet above the base of the overlying Summerville Formation
Perched-groundwater in the Dakota Sandstone and Burro Canyon Formation onginates mainly
from precipitation and local recharge sources such as unlined reservoirs (Kirby, 2008) and is
used on a liimted basis to the north (upgradient) of the site because it is more easily accessible
than the Navajo/Entrada aquifer Water quality of the Dakota Sandstone and Burro Canyon
Formation is generally poor due to high total dissolved solids ('TDS") The saturated thickness
of the perched water zone is generally higher to the north of the site
4.3 Perched Zone Hydrogeology
Perched groundwater beneath the site occurs pnmanly withm the Burro Canyon Formation
Perched groundwater at the site has a gerierally low quality due to high total TDS in the range of
approximately 1,100 to 7,900 milhgrams per liter ("mg/L"), and is used pnmanly for stock
watenng and imgation m the areas upgradient (north) of the site where generally higher
saturated thicknesses increase well yields Perched water is supported within the Burro Canyon
Formation by the underlying, fine-grained Bmshy Basin Member Figure 3 is a contour map
showing the approximate elevation of the contact of the Burro Canyon Formation with the
Bmshy Basin Member, which essentially forms the base of the perched water zone at the site
Contact elevations between the Burro Canyon Formation and Bmshy Basin Member in Figure 3
are based on perched monitonng well dnllmg and geophysical logs and surveyed land surface
elevations As indicated, the Burro Canyon Formation/Brushy Basm Member contact (although
;
Corrective Action Plan for Nitrate 16
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
irregular because it represents an erosional surface) generally dips to the south/southwest beneath
the site
Appendix A contains hydrogeologic cross-sections that intersect withm the mtrate plume These
cross-sections show the site lithoiogy above the Bmshy Basm Member, perched water within the
Dakota Sandstone/Burro Canyon Formation, and the occurrence of mtrate withm the perched
water As shown m Figure A 2, relatively thick conglomeratic intervals exist within the saturated
zone at MW-31, located at the downgradient edge of the mtrate plume As discussed below,
these intervals appear to pinch out to the south (downgradient) and to the west (cross-gradient) of
MW-31
Less conglomeratic material is present m the saturated zone at MW-30 and MW-3A than at MW-
31, as shown in the attached lithologic logs (Appendix B). Thin conglomeratic zones
(approximately 1-2 feet thick) occur at the base of the perched zone m MW-31 and MW-3 A
Detailed lithologic logs for MW-5, MW-11, MW-14 and MW-15 are not available to assess the
presence of conglomeratic material at those locations However, saturated conglomeratic
matenals were not encountered at MW-34 and MW-37 (located adjacent to MW-15), as shown
m the attached lithologic logs
Based on the available information, sigmficant conglomeratic honzons within the saturated
perched zone do not appear to exist at or downgradient of MW-30 Furthermore, hydraulic test
data from MW-30 and MW-31 indicate that the conglomeratic zones in MW-31 do not enhance
the conductivity at MW-31 The hydraulic conductivity estimates (based on Kansas Geological
Survey ("KGS") solution analysis of automatically logged slug test data) for MW-30 and MW-
31 are similar The hydraulic conductivity estimates for MW-30 and MW-31, respectively, are 1
X 10""^ cm/s and 7 x 10'^ cm/s (HGC, 2005)
4 3 1 Lithologic and Hydraulic Properties
Although the Dakota Sandstone and Burro Canyon Formations are often descnbed as a single
umt due to their smulanty, previous investigators at the site have distinguished between them
The Dakota Sandstone is a relatively hard to hard, generally fine-to-medium grained sandstone
cemented by kaolinite clays The Dakota Sandstone locally contains discontinuous mterbeds of
siltstone, shale, and conglomeratic matenals Porosity is pnmanly intergranular The underlying
Burro Canyon Formation hosts most of the perched groundwater at the site The Burro Canyon
Formation is similar to the Dakota Sandstone but is generally more poorly sorted, contains more
conglomeratic matenals, and becomes argillaceous near its contact with the underlying Bmshy
Basm Member The hydraulic conductivities of the Dakota Sandstone and Burro Canyon
Formation at the site are generally low
Corrective Action Plan for Nitrate 17
White Mesa Uramum Mill Near Blandmg Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
No significant joints or fractures withm the Dakota Sandstone or Burro Canyon Formation have
been documented m any wells or bonngs installed across the site (Kmght-Piesold, 1998) Any
fractures observed in cores collected from site bonngs are typically cemented, showing no open
space
4.3 1.1 Dakota
Porosities of tiie Dakota Sandstone range from 13 4% to 26%, averaging 20%, and water
saturations range from 3 7% to 27 2%, averaging 13 5%, based on samples collected dunng
installation of wells MW-16 (abandoned) and MW-17 (Figure 1-2) The average volumetiic
water content is approximately 3% The hydraulic conductivity of the Dakota Sandstone based
on packer tests m bonngs installed at the site ranges from approximately 2 7 x 10'^ centimeters
per second ("cm/s") to 9 1 x 10""* cm/s, with a geometnc average of 3 9 x 10"^ cm/s
4.3 1.2 Burro Canyon
The average porosity of the Burro Canyon Formation is similar to that of the Dakota Sandstone
Porosity ranges from 2% to 29 1%, averaging 18 3%, and water saturations of unsaturated
matenals range from 0 6% to 77 2%, averaging 23 4%, based on samples collected from the
Burro Canyon Formation at MW-16 (abandoned), located beneatii new tailings Cell #4A TITAN
(1994) reported that the hydraulic conductivity of the Burro Canyon Formation ranges from 1 9 x
10"^ to 1 6 X 10 cm/s, with a geometnc mean of 1 1 x 10'^ cm/s, based on the results of
12 pumpmg/recovery tests performed in momtonng wells and 30 packer tests performed in
bonngs pnor to 1994 Subsequent hydraulic testing of perched zone wells has yielded a range of
2 X 10-^ to 0 01 cm/s (HGC, 2009a)
In general, the highest hydraulic conductivities and well yields are in the area of the site
immediately northeast and east (upgradient to cross gradient) of the tailings cells A relatively
continuous, higher conductivity zone that is associated with the chloroform plume (HGC, 2007b)
has been inferred to exist in this portion of the site Analysis of drawdown data collected from
this zone dunng long-term pumping of MW-4, MW-26, and TW4-19 (Figure 1-2) yielded
estimates of hydrauhc conductivity ranging from 4 x 10'^ to 1 x 10'^ cm/s (HGC, 2004) The
decrease in perched zone hydraulic conductivity south to southwest of this area indicates that this
higher conductivity zone "pinches out" (HGC, 2007b)
Hydraulic conductivities downgradient of the taihngs cells are generally low Hydraulic tests at
wells located at the downgradient edge of the cells, and south and southwest of the cells yielded
geometnc average hydrauhc conductivities of 2 3 x 10'^ and 4 3 x 10'^ cm/s depending on the
testing and analytical methods The low hydraulic conductivities and shallow hydraulic gradients
Correcuve Acuon Plan for Nitrate 1 g
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7,2012
downgradient of the tailings cells result in average perched groundwater pore velocity estimates
that are among the lowest on site (approximately 1 7 ft/yr to 3 2 ft/yr based on calculations
presented in HGC, 2009a)
Hydraulic conductivities within the general area of the mtrate plume are based pnmanly on
analysis of slug tests at wells MW-27, MW-30, MW-31, TW4-20, TW4-21, TW4-22, TW4-24,
TW-25, TWN-1, TWN-2, TWN-3, and TWN-18 (HGC, 2005 and HGC, 2009a) The hydrauhc
conductivity at MW-11 was based on a pumping test reported by UMETCO (1993) and the
hydraulic conductivity at TW4-19 was based on long-term pumping of that well for chloroform
removal (HGC, 2004). Hydraulic conductivity estimates range from approximately 2 7 x 10'^ to
1 4 x 10"^ cm/s, and have a geometnc average of 1 2 x lO'* cm/s, assurmng unconfined
conditions (Table 2) The transnussivities of many wells within the nitrate plume are similar to
wells that are pumped for chloroform removal
4 3 2 Perched Groundwater Row
Perched groundwater flow at the site has historically been to the south/southwest (HGC, 2007b)
Figure 4 IS a perched groundwater elevation contour map for the third quarter of 2011 These
contours are based on water levels measured in the perched groundwater monitonng wells shown
m the figure Local depression of the perched water table occurs near wells MW-4, TW4-4,
TW4-19, TW4-20, and MW-26 These wells are pumped to reduce chloroform mass in the
perched zone east and northeast of the tailings cells as discussed in HGC (2007a)
Perched water mounds are associated with wildlife ponds on the east side of the site The
mounds are likely the result of seepage from the unlined ponds An apparent perched water
mound also exists m the vicimty of TWN-2 just north of the Mill site The apparent perched
water mound near TWN-2 is likely a residual mound resulting from low conductivity conditions
(Table 2) and the location of TWN-2 within the footpnnt of the histoncal pond (Figure 8)
Although the histoncal pond no longer exists and does not contain standing water, the remaimng
topographic depression associated with the pond likely resulted m enhanced infiltration of
precipitation before re-gradmg of the land surface in that area, circa 1980 Slightiy enhanced
infiltration of precipitation and low conductivity conditions at TWN-2 likely allowed the mound
to persist The decay of the mound is expected to be slow because of the low conductivity
A dry area to the southwest of Cell 4B is defined by the area where the knged Bmshy Basm
contact elevation rises above the knged perched water level elevation The lateral extent of the
dry area shown in Figure 4 is currently under investigation The installation of wells along the
southern and westem margins of Cell 4B m August, 2010 and Apnl, 2011 indicate that the dry
Correcuve AcUon Plan for Nitrate 19
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Conective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
zone extends at least from the southwest central portion of Cell 4B to the southwest comer of
Cell 4B
Beneath and downgradient of the taihngs cells, on the west side of the site, perched water flow is
south-southwest to southwest On the eastern side of the site perched water flow is more
southerly Because of mounding near wildlife ponds, flow direction ranges locally from westerly
(west of the ponds) to easterly (east of the ponds) Perched zone hydrauhc gradients currently
range from a maximum of approximately 0 07 ft/ft east of tailings Cell #2 (near well TW4-14) to
approximately 0 01 ft/ft downgradient of the tailings cells Gradients may be steeper locally near
pumping wells (for example near TW4-20, where the gradient reaches approximately 0 09 ft/ft)
Perched water discharges m spnngs and seeps along Westwater Creek Canyon and Cottonwood
Canyon to the west-southwest of the site, and along Corral Canyon to the east of the site, (Figure
1-1) where the Burro Canyon Formation outcrops The closest discharge points downgradient of
the tailings cells are Westwater Seep (more than 2,000 feet downgradient) and Rum Spnng
(more tiian 9,000 feet downgradient [HGC, 2010])
4 3 3 Saturated Thickness
The saturated thickness of the perched zone as of the third quarter of 2011 ranges from
approximately 92 feet m the northeastern portion of the site to less than 5 feet in the southwest
portion of the site (Figure 5) A samrated thickness of approximately 2 feet occurs in well
MW-34 along the south dike of new tailings Cell 4B, and the perched zone is apparentiy dry at
MW-33 located at the southwest comer of Cell 4B Depths to water range from approximately 17
to 18 feet in the northeastern portion of the site (near the wildhfe ponds) to approximately 114
feet at the southwest margin of tailings Cell #3 (Figure 6) The relatively large samrated
thicknesses in the northeastern portion of the site are likely related to seepage from the wildlife
ponds located northeast and east of the tailings cells.
Although sustainable yields of as much as 4 gpm have been achieved in wells intercepting the
larger saturated thicknesses and higher conductivity zones in the northeast portion of the site,
perched zone well yields are typically low (<0 5 gpm) due to the generally low hydraulic
conductivity of the perched zone Sufficient productivity can generally be obtained only in areas
where the saturated thickness is greater, which is the pnmary reason that the perched zone has
been used on a limited basis as a water supply to the north (upgradient) of the site, but has not
been used downgradient of the site
Correcuve AcUon Plan for Niuate 20
White Mesa Uranium Mill Near Blandmg, Utah
Revised NiUate Corrective AcUon Plan redbne Fmal 05 07 12 Fnl doc
May 7.2012
4.4 Summary
Perched groundwater at the site is hosted pnmanly by the Burro Canyon Formation, which
consists of a relatively hard to hard, fine- to medium-grained sandstone contaimng siltstone,
shale and conglomeratic matenals The Burro Canyon Formation is separated from the
underlying regional Navajo/Entrada aquifer by approximately 1,000 to 1,100 feet of Momson
Formation and Summerville Formation matenals having a low average vertical hydraulic
conductivity The Bmshy Basin Member of the Momson Formation is a bentomtic shale that lies
immediately beneath the Burro Canyon Formation and forms the base of the perched water zone
at the site Figure 2 is a photograph of the contact between the Burro Canyon Formation and the
underlying Bmshy Basm Member taken from a location along highway 95 immediately north of
the Mill This photograph illustrates the transition from the cliff-forming sandstone of the Burro
Canyon Formation to the slope-forming Bmshy Basin Member Based on hydrauhc tests at
perched zone momtonng wells, the hydraulic conductivity of the perched zone ranges from
approximately 2 x 10'^ to 0 01 cm/s
Perched water flow is generally from northeast to southwest across the site Beneath and
downgradient of the tailings cells, on the west side of the site, perched water flow is
south-southwest to southwest. On the eastem side of the site perched water flow is more
southerly Because of mounding near wildlife ponds, flow direction ranges locally from westerly
(west of the ponds) to easterly (east of the ponds) Perched water generally has a low quality,
with total dissolved solids ranging from approximately 1,100 to 7,900 mg/L, and is used
pnmanly for stock watering and imgation north (upgradient) of the site
Depths to perched water range from approximately 17 to 18 feet near the wildlife ponds m the
northeastern portion of the site to approximately 114 feet at the southwestern margm of taihngs
Cell #3 Saturated thicknesses range from approximately 92 feet near the wildhfe ponds to less
than 5 feet m the southwest portion of the site, downgradient of the tailings cells A saturated
thickness of approximately 2 feet occurs in well MW-34 along the south dike of new taihngs
Cell 4B, and the perched zone is apparently dry at MW-33 located at the southwest comer of
Cell 4B Although sustainable yields of as much as 4 gpm have been achieved in wells
penetrating higher transmissivity zones, well yields are typically low (<0 5 gpm) due to the
generally low hydraulic conductivity of the perched zone
Hydraulic testing of perched zone wells has yielded a range of approximately 2 x 10" to 0 01
cm/s In general, the highest hydraulic conductivities and well yields are m the area of the site
immediately northeast and east (upgradient to cross gradient) of the tailings cells A relatively
continuous, higher hydraulic conductivity zone associated with the chloroform plume has been
inferred to exist in this portion of the site Analysis of drawdown data collected from this zone
Correcuve Acuon Plan for Nitrate 21
White Mesa Uramum Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7.2012
dunng long-term pumping of MW-4, TW4-19, and MW-26 (TW4-15) yielded estimates of
hydraulic conductivity ranging from 4 x 10"^ to 1 x 10'^ cm/s
Hydraulic conductivities downgradient of the tailings cells are generally low Hydraulic tests at
wells located at the downgradient edge of the cells, and south and southwest of the cells yielded
geometiic average hydrauhc conductivities of 2 3 x 10'^ and 4 3 x 10'^ cm/s depending on the
testing and anal)^cal method The low hydraulic conductivities and shallow hydraulic gradients
downgradient of the tailings cells result m average perched groundwater pore velocity estimates
that are among the lowest on site
Hydraulic conductivities within the general area of the mtrate plume are based pnmanly on
analysis of hydraulic tests as discussed m Section 4 3 Hydraulic conductivity estimates ranged
from approximately 2 7 x 10'^ to 1 4 x 10'^ cm/s, and have a geometnc average of 1 2 x 10"^
cm/s, assuimng unconfined conditions The transnussivities of many wells withm the mtrate
plume are siimlar to wells that are pumped for chloroform removal
4.5 Nitrate Occurrence
Nitrate withm the area shown m Figure 1-2 was first detected m wells TW4-19, TW4-22, TW4-
24, and TW4-25 that were installed as part of the investigation of a chloroform plume first
discovered at perched well MW-4 m 1999. Investigation of mtrate has included the installation
of 19 temporary (TWN-senes) perched zone mtrate monitoring wells to delineate and momtor
the mtrate (Figure 1-2) The extent of mtrate contamination is descnbed below and in further
detail in Section 5 1 and its associated figures
Nitrate concentrations in the perched zone as of the third quarter of 2011 are shown in Figure 7
Nitrate concentrations m the perched zone have ranged from non-detect to a maximum of 69
[igfL at well TWN-2 m the second and third quarters of 2010 Nitrate concentrations at
downgradient wells MW-30 and MW-31 have been relatively stable, ranging from 15 to 17 mg/L
at MW-30 and from 20 to 22 mg/L at MW-31 between tiie first quarter of 2010 tiirough tiie third
quarter of 2011
Constituents associated with the mtrate include chlonde, and m the east-central portion of the
plume, chloroform The association of nitrate with chloroform is discussed in HGC, 2007b
4 5 1 Source Areas
As discussed above, a number of potential Mill and non-Mill sources were identified in INTERA
(2009a), and INTERA (2011), as hsted below
Correcuve AcUon Plan for Nitrate 22
White Mesa Uramum Mill Near Blandmg, Utah
Revised Nitrate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
1 Mam leach field (also known as leach field east of scale house, 1985 to present)
2 Sewage vault/lift station (currently active)
3 Scale house leach field, (also known as leach field south of scale house, 1977-1979)
4 Former office leach field
5 Ammoma tanks
6 SAG leach field (leach field north of Mill building, 1998 to 2009)
7 Cell 1 leach field (leach field east of Cell #1, up to 1985)
8 Hy Ash Pond
9 Sodium chlorate tanks (as a potential chlonde source)
10 Ammomum sulfate crystal tanks
11 Lawzy sump
12 Lawzy Lake
13 Former vault/lift station (to former office leach field, 1992 to 2009)
14 Truck shop leach field (1979-1985)
15 New Counter Cunrent Decant/Solvent Exti-action ("CCD/SX") leach field (currentiy
active)
16 Histoncal Pond
17 Wildhfe pond
18 CCD (included inadvertently and eliminated)
19 YC Precip Mini-Lab
20 V205 Mini-Lab & V205 Precip
21 SXMim-Lab
22 Chem Lab
23 Met Lab
24 V205 oxidation tanks
25 Natural mtrate reservoir
26 - 32 Seven other ponds or pond-like sources
Figure 8 shows the locations of potential source areas 1 through 24
Based on the investigation and source evaluations completed to date, there are no known current
unidentified or unaddressed ongoing sources There appear to have been a number of known and
potential histonc sources, however, it has not been possible to confirm or quantify the
contnbution of each Soil contamination associated with the ammonium sulfate tanks as a
potential source to perched groundwater is addressed as Phase I of this CAP
Corrective Action Plan for Nitrate 23
White Mesa Uranium Mill Near Blanding, Utah
Revised Niuate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
Although the actual source or sources have not been identified and quantified, based on analysis
of the concentrations withm and the areal extent of the plume over the past two years, Demson
and DRC have concluded there is no known sigmficant unaddressed currently active source That
IS, analytical results indicate that neither the average concentration within the plume nor the areal
extent of the plume has increased dunng the penod it has been momtored Therefore, although
the source or sources have not been defimtively determined, sufficient information exists to
bound and charactenze the plume and plan remedial actions for its control
4 5 2 Nitrate Concentration Trends
Table 3 provides nitrate concenti-ations detected at wells within the nitrate plume from the first
quarter, 2010 through the third quarter of 2011 Over the last year (between the third quarter,
2010 and third quarter, 2011) three wells decreased m concentration, three increased, and three
remained the same The well with the highest concentrations, TWN-2, decreased from 69 mg/L
to 33 mg/L The average mtrate concentration withm the plume decreased from 24 4 mg/L to
19 7 mg/L At the downgradient edge of the plume, monitor wells MW-30 and MW-31 have
been sampled since June 2005 Dunng the penod from June 2005 to December 2011, samples
from MW-30 have had an average mtrate concentration of 16 mg/L with a standard deviation of
1 4 mg/L (Figure 9-1) Dunng the same penod, samples from MW-31 have had an average
mtrate concentration of 22 mg/L with a standard deviation of 2 7 mg/L (Figure 9-1) Thus, the
downgradient edge of the plume has been relatively stable over a six and one half year penod
The information presented above indicates that concentrations within the plume are relatively
stable but the highest concentrations appear to be declimng Figure 9-2 compares the extent of
the mtrate plumes in the third quarter of 2010 and the third quarter of 2011 As indicated, the
plume boundanes are relatively stable, likely the result of the generally low hydraulic
conductivity of the perched zone, and the ongoing pumping related to the chloroform plume
Correcuve AcUon Plan for Nitrate 24
White Mesa Uranium Mill Near Blanding, Utah
Revised Niuate Correcuve Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
5. CHARACTERIZATION OF STUDY AREA
The study area encompasses a region in the northeastern portion of the site where the nitrate
plume (defined by concentrations > 10 mg/L) has been detected and bounded by a senes of
mtrate and chloroform investigation wells (Figure 1-2) Wells within the plume are MW-30 and
MW-31, and temporary wells TW4-19, TW4-21, TW4-22, TW4-24, TW4-25, TWN-2 and
TWN-3 (Figure 7) Wells MW-5, MW-11, MW-25, MW-26, MW-27, MW-28, MW-29, MW-
32, TW4-16, TW4-18, TWN-1, TWN-4, TWN-7, and TWN-18 bound tiie plume As of the
second quarter of 2011, MW-5, MW-11, MW-25, MW-29, and MW-32 were non-detect for
mtirate Hydraulic charactenzation of the study area has been based on data collected from wells
within and near the plume as discussed in Section 4 The extent and hydrogeology of the study
area is discussed below
5.1 Extent of Study Area
The mtrate plume that is the focus of this CAP is confined to the region of the perched zone
contaimng mtrate concentrations exceeding 10 mg/L located south of TWN-18 and north of
MW-11 The area having mtrate exceeding 10 mg/L, as of the third quarter of 2011, is shown in
Figures 1-2 and 7 This area extends from the northeast portion of the tailings cells to the area
upgradient (north-northeast) of the tailings cells The highest nitrate concentrations have
histoncally been detected at TWN-2, within the northern (upgradient) portion of tiie plume
TWN-2 IS located within the area of the histoncal pond (Figure 8)
The histoncal pond was active as far back as the 1920s, as much as 60 years pnor to the
establishment of the White Mesa Mill Satellite photos taken over the years and dating back to
the 1950s indicate that the histoncal pond was one of the major agncultural/livestock ponds in
the area and typically contained water Records or information have not been obtained to
evidence the actual uses of the pond over the years
Areas of detectable mtrate that are not continuous with the above defined area exist to the
northwest (near TWN-9 and TWN-17) and to the east-southeast associated with the chloroform
plume Nitrate concentrations within these areas are typically less than 10 mg/L although
sporadic detections at or slightly above 10 mg/L have occurred at some locations Areas to the
northeast are not a target of this CAP, and mtrate associated with the chloroform plume is
addressed by the ongoing chloroform pumping
The mtrate plume, as defined by the 10 mg/L concentration boundary, is bounded by wells MW-
5, MW-11, MW-25, MW-26, MW-27, MW-28, MW-29, MW-32, TW4-16, TW4-18, TWN-1,
TWN-4, TWN-7, and TWN-18 As of tiie second quarter of 2011, MW-5, MW-11, MW-25,
Correcuve AcUon Plan for Nitrate 25
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
MW-29, and MW-32 were non-detect for mtrate The plume is bounded to the south by MW-5
and MW-11, to the east by MW-27, MW-28, MW-29 and TWN-7, to the nortii by TWN-18, and
to the west by MW-25, MW-26, MW-32, TWN-1, TWN-4, TW4-18, TW4-16, and TW4-20
Additional wells to the south (downgradient) of the plume include MW-3, MW-14, MW-15 and
MW-37
5.2 Hydrogeology
A descnption of the hydrogeology of the site in the vicimty of tiie mti-ate plume is provided m
Section 3, and hydrogeologic cross-sections are provided m Appendix A. Perched zone hydraulic
conductivities in the vicinity of the nitrate plume are in the imddle to high end of the range
measured at the site The geometnc average of approximately 1 2 x lO'"^ cm/s is slightiy lower
than typical for the area of the chloroform plume located east and southeast of the mtrate plume
(Figure 10)
Perched groundwater flow in the area of the nitrate plume is generally southwesterly Saturated
thicknesses in the vicimty of the plume are generally higher than m areas to the south and
southwest In the vicimty of the mtrate plume (Figure 5) they range from a maximum of
approximately 87 ft at TW4-25 to approximately 30 ft at MW-30 In general, satiirated
thicknesses increase toward the northeast, where the wildlife ponds are located, and are locally
affected m tiie vicimty of the plume by pumping at MW-26, TW4-19, and TW4-20
Hydraulic conductivities within the general area of the mtirate plume are based pnmanly on
analysis of slug tests as discussed in Section 3 Hydraulic conductivity estimates range from
approximately 2 7 x 10'^ to 1 4 x 10"^ cm/s, and have a geometnc average of 1 2 x 10"^ cm/s
(Table 2) The transnussivities of many wells within the mtrate plume are sirmlar to wells that
are pumped for chloroform removal
Corrective Acuon Plan for Nitrate 26
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
6. CORRECTIVE ACTION CONCENTRATION LIMITS
The corrective action concentration limit for nitrate is 10 mg/L This concentration is considered
to bound the outer extent of the plume and is the ultimate target for reducing nitrate
concentrations within the plume As discussed in Section 9, once the mtrate concentrations in all
momtonng wells are lOmg/L or less, concurrence with DRC will be sought that the plume is
remediated and the corrective action complete
Correcuve AcUon Plan for NiUate 27
White Mesa Uranium Mill Near Blanding, Utah
Revised NiUate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
Correcuve Acuon Plan for Nitrate 28
White Mesa Uraiuum Mill Near Blanding, Utah
Revised NiUate Correcuve Action Plan redbne Final 05 07 12 Fnl doc
May 7,2012
7. CORRECTIVE ACTION PLAN - CONSTRUCTION AND OPERATION
The corrective action for the nitrate plume is proposed to occur in three phases
In Phase I, Denison proposes to constmct a sloped, curbed and drained concrete pad of six inches
m depth over an area covenng the areal extent of contaimnation identified dunng the
contamination investigation Denison also proposes a future removal of contaminated soil at the
time of Mill site reclamation and, for conservatism, proposes to revise the reclamation surety
estimate to include a volume of soil to be removed and placed m the tailings cells of twice the
volume of contaminated soil identified m the contamination investigation
Phase II will consist of pumpmg four wells witiun tiie mtrate plume, (TW4-22, TW4-24, TW4-
25, and TWN-2) Phase II relies on both pumping and natural attenuation to remove mtrate mass,
reduce nitrate concentrations withm the plume, and mimmize or prevent plume migration
Included in Phase II are continued momtonng within and outside the plume to venfy plume
boundanes (as defined by a concentration of 10 mg/L), estimate changes in hydraulic capture,
and track changes in mtrate concentrations within the plume
Phase in, if required, will be conducted in consultation with the Executive Secretary If
implemented. Phase IE will consist of a transport assessment, a hazard assessment, and an
exposure assessment along with a corrective action assessment including an evaluation of best
available remedial technologies. Selection of a technology for implementation will be based on
an evaluation whether the technology will remediate contamination to as low as is reasonably
achievable, if tiie 10 mg/L standard is not reasonably achievable One possible outcome of these
evaluations could be an application for altemate corrective action concentration liimts
("ACACL")
After implementation of Phase II and Phase HI and once residual concentrations have dropped to
10 mg/L or less at all momtored locations or an ACACL has been granted, concurrence with the
Executive Secretary will be sought that the corrective action is complete Phase II has
contingencies to be implemented if needed based on momtonng as discussed m Section 8 The
termination of Phase II and implementation of Phase HI will be with the concurrence of the
Executive Secretary and will be based on assessments conducted dunng Phase II
An important goal of Phase IH is to ensure that mtrate concentrations exceeding the action level
will not migrate to any point of exposure within the applicable regulatory time frame This
imgration of the nitrate plume is not expected to occur However, the decision as to when to
terminate Phase II and implement Phase III will be based on Phase II monitoring data and
Correcuve AcUon Plan for Nitrate 29
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
quantitative calculations that mdicate tiiat, based on Phase II results, this Phase III goal is
attainable.
7.1 Phase I Description and Rationale
The potential contamination source to be addressed in Phase I consists of alluvial soil m the area
of the Mill's outdoor ammonium sulfate storage tanks as depicted in Figure 11-1 As shown in
Figure 11-1, the ammonium sulfate tanks and associated soil contaimnation are located to the
east of the Mill process building The tanks are currently situated over an uncurbed concrete slab,
which has suffered some detenoration over the years The tank area is bounded to the west by the
Mill buildmg, to the soutii by the V2O5 Mim Lab and Precipitation Area, and to tiie north by the
Mill's Pulp Storage Tanks That is, the ammomum sulfate tanks are located in a relatively
congested and (on three sides) built out area The proximity of the Mill bmlding and other tanks
precludes the ability to perform an extensive soil excavation/contaminated soil removal at the
current time Therefore, consistent with the SCA, Denison proposes to perform the contaminated
soil corrective action phase m two steps, 1) constmction of a concrete cover to remain in place
dunng the operating life of the Mill, and 2) a contaminated soil excavation to occur dunng the
Mill reclamation at final Mill closure
7 1 1 Approximation of the Lateral Extent of Contamination and Concrete Cover
Per Section 11A(1) of the SCA, Phase I is required to include a control for the soil contamination
observed at the ammonium sulfate tanks To meet this objective, Demson proposes to constmct a
sloped and drained concrete pad of six inches in depth over an area covering the areal extent of
contamination identified dunng the contamination investigation to prevent infiltration of surface
water into the contaminated soil Existing data consists of analytical data from two of the soil
bonngs collected dunng the June 2011 contaimnation investigation as shown in Figure 11-1 In
order to venfy that the proposed concrete pad meets the objective of covenng the lateral extent
of contanunation, Denison will implement a soil samphng program prior to the completion of the
concrete pad The soil sampling program is designed to provide data to delineate, approximately,
the lateral extent of contamination
The soil sampling program will be conducted substantially m accordance with the DRC-
approved field and quality assurance procedures implemented dunng the Phase 1, (Part 1) Nitrate
Investigation as descnbed in the Nitrate Investigation Phase 1 Work Plan, dated May 13, 2011
A summary of the soil samplmg program to be conducted dunng Phase I of the CAP, with any
necessary changes from the Nitrate Investigation Phase I Work Plan, dated May 13, 2011, is as
follows
Correcuve AcUon Plim for NiUate 30
White Mesa Uramum Mill Near Blanding, Utah
Revised NUrate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
7111 Soil Sampling Program Objective and Design
The objective of this soil sampling program is to delineate, approximately, the lateral extent of
contamination m order to determine the extent of the concrete pad necessary to cover the soil
contaimnation identified dunng the Phase I investigation To meet this objective, 18 Geoprbbe
borings will be conducted down to bedrock refusal at each of the locations shown on Figure 11-
2B Three (3) samples will be collected from each Geoprobe core location Soil core samples
will be collected from the bottom one foot of each of the following intervals, based on the total
depth of penetration at each site top 1/3, middle 1/3, and bottom 1/3
Select soil core samples will be sent to the analytical laboratory for analysis of nitrate (as N), and
ammonia (as N) as descnbed below Since the purpose of this samphng program is to confirm
the lateral extent of soil contamination (in the form of nitrate and ammonia) resulting from the
ammomum sulfate tank source, no other analytes are required Soil analysis will be conducted by
an environmental laboratory currentiy certified by the State of Utah, using EPA approved sample
and analysis methods
Demson anticipates that the presence of ammoma contamination will dimimsh with distance
from the ammomum sulfate tanks The imtial row of samples will be collected 3 feet from the
northeast edge of the proposed concrete pad shown in Figure 11-2B If the results of the analysis
of the imtial sample row mdicate that ammoma and mtrate levels do not exceed DRC's proposed
screemng levels of 2 times the background levels detenmned m the June 2011 investigation,
specifically 4 29 mg/kg for ammoma and 4 38 mg/kg for nitrate, no further samples will be
analyzed and the pad will be constmcted as shown in Figure 11-2B That is, if the imtial samples
are below the screemng levels, it will be concluded that the contamination will be adequately
covered by the proposed design, and the soil sampling program will be considered complete
If the results of analysis of the imtial sample row indicate that the contamination extends beyond
the area delineated by the imtial row, that is, one or more samples in the imtial row exceed the
screemng levels, the remaimng samples for one or more additional sampling rows will be
analyzed for nitrate (as N), and ammoma (as N) The concrete pad will be sized to extend to the
first row of samples whose analysis do not indicate mtrate or ammoma exceeding the screemng
levels
7112 Field Activities/Sampling Methods
In order to minimize the potential for multiple mobilizations of the Geoprobe unit, three discrete
sets of samples will be collected in one sampling event dunng this investigation Each discrete
set of samples will be collected in a lateral line or "row" along the northeast face of the proposed
Corrective Action Plan for Nitrate 31
White Mesa Uramum Mill Near Blanding, Utah
Revised Nitrate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
concrete pad as shown in Figure 11-2B Samples will be collected every approximately 12 5 feet
laterally along the edge of the concrete pad The first row of discrete samples will be
approximately three feet from the edge of the proposed concrete pad The two successive rows
will be stepped-out approximately ten feet from the previous row of samples The samples
collected m the two successive rows will be archived for potential later analysis of mtrate and
ammonia if necessary All archived samples will be stored in accordance with the analytical
method requirements for temperature Expedited tum around will be requested for the analysis of
the first row of soil samples, so that if any additional analyses are required, the additional
analyses can be completed within the specified analytical holding times Based on this sampling
strategy, 54 soil samples (and 6 duphcates and 3 rmsates), will be collected
7 1.1 3 Sample Handling and Custody
Each sample collected dunng tins sampling program will be identified using a umque sample
identification number ("ID") The descnption of the sample type and the sample name will be
recorded on the cham-of-custody ("COC") forms, as well as m the field notes Geoprobe bonng
samples will be named according to the bonng location and top and bottom of the depth interval
at which they were collected, following the convention PlAXX-tt-dd, where PIAXX is the first
boring in the first row of samples and tt is the top of the depth interval and dd is the bottom of
depth interval expressed m feet below ground surface. Additional rows of samples will be
identified as PlA2XX-tt-dd Duplicate samples will carry the same identification as the parent
sample with the temunal letter "D" to identify them as a duplicate Similarly, nnsate samples
will carry the sample identification of the sample collected pnor to the nnsate followed by the
temnnal letter "R"
Samples will be collected into re-sealable plastic bags, which will be labeled with the sample
identification and homogenized by vigorously shaking and mixing the contents until the samples
are visibly uniform A mimmum sample volume of 100 grams will be collected from each
location Sample containers will be provided by the laboratory, certified as clean, and will be
filled directly from the plastic bags Archive sample aliquots will be maintained m the plastic
bags at the Mill for the duration of the analytical holding times to provide additional backup
sample for analysis if necessary Archive sample aliquots will be stored m accordance with the
analytical method requirements for sample preservation
Standard sample custody procedures as described in the DRC-approved Nitrate Investigation
Phase 1 Work Plan, dated May 13, 2011 will be used to maintain and document sample integnty
dunng collection, transportation, storage, and analysis ,
Correcuve Acuon Plan for Niuate 32
White Mesa Uranium Mill Near Blanding, Utah
Revised Niuate Correcuve Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
Samples will be shipped to the analytical laboratory using an overmght camer such as Federal
Express Samples will be analyzed withm the analytical method specified holding times
7 1.1.4 Analytical Methods
For comparability, the soil analytical methods will be the same as those used for the 2011 mti-ate
contamination investigation
All soil samples will be submitted to the analytical laboratory for SPLP using EPA Method 1312
using Extraction Fluid #3. Method 1312 will produce a leachate of all soil samples which will be
analyzed for mtrate and mtrogen as ammoma using EPA Method 353 2, and EPA method 350 1
respectively Method 1312 will produce a sufficient volume of leachate to complete the mtrate
and ammoma analyses as well as any method-required QC analyses
The soil samples are being leached and analyzed using water methodologies, which will yield
concentrations m liquid umts (such as mg/L) The laboratory will report all soil samples in two
ways 1) as a leachate in mg/L and 2) as a soil m mg/kg on a dry weight basis
The reporting hunts ("RLs") for the methods are 0 01 mg/L for mtrate and 0 05 mg/L for
ammoma These RLs are sufficiently sensitive to allow determination of soil contamination
below the screemng levels
7115 Quality Control
Quality control ("QC") samples will be collected in the field dunng the sampling effort and will
include one duplicate per ten analytical samples and one nnsate sample per twenty samples
Rinsate samples will be collected using deiomzed ("DI") water from a third party commercial
source Duplicates will be assessed through the calculation of a relative percent difference
("RPD") and rmsate samples will be assessed based on any detections reported and their
magmtude relative to the sample results The QC procedures set forth m the Nitrate Investigation
Phase 1 Work Plan, dated May 13, 2011 will be used for the assessment of the soil samples
collected dunng tins program
Analytical laboratory QC, audits, instmment cahbration, internal QC procedures, detailed COC
procedures, orgamzational responsibilities, and other specific details regarding sample collection
will be completed in accordance with the DRC-approved Nitrate Investigation Phase I Work
Plan, dated May 13, 2011
Correcuve AcUon Plan for Nitrate 33
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Correcuve Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
7 1 2 Construction of the Phase I Action
Demson proposes to construct a sloped, curbed, and drained concrete pad of six inches in depth
over an area covenng the lateral extent of contamination identified dunng the contamination
investigation Because the ammonium sulfate tanks are surrounded by existing concrete
stmctures to the south, west, and north, the new concrete pad will extend to the east of the Mill
building The existing concrete pad will be resurfaced and sloped to drain to the existing
collection area/sump inside the Mill building, which retums solutions to the process This
resurfaced area will be constmcted with a curb of approximately 6 inches m height In addition, a
new concrete slab will be extended to the eastem edge of the surrounding stmctures This new
slab will also be sloped to dram to an existing collection area/sump m the Mill bmlding A rolled
curb will be constmcted with an access ramp to allow supplier trticks sufficient access to refill
the tanks The proposed cover design is depicted in Figure 11-2A and B
The only subsurface piping in the vicimty of the ammomum sulfate tanks is a segment of the
underground portion of the Mill fire water system Figure 11-3 shows the location of the
subsurface portion of the fire water line Due to the need to maintain continual pressure on the
fire water system, the system already contains mstmmentation (an alarm system) to indicate
when the pressure makeup pump starts up as a response to leaks, breaks, or loss of pressure As
indicated by the pump alarm history, the firewater system has no history of leakage, and is not
expected to be a source of hydraulic head in the vicinity The only other subsurface process
piping on the Mill site consists of two pairs of lines one coohng water recirculation loop, and
one vanadium product liquor loop, for which the buried portion begins approximately more than
100 feet southeast of the ammomum sulfate tanks (75 feet from the nearest comer of the concrete
pad proposed in Figure 11-4), and "around the comer" from the ammomum sulfate tanks - east
of the easternmost wall of the bmlding's "L" These two piping loops are new, have had no
history of leakages, and are too far from the ammomum sulfate tanks to be a source of hydraulic
head m the vicimty of the tanks All other process piping is above grade
Consistent with Section llA(l)(b)(i) of the SCA, Demson provided a detailed plan and schedule
for constmction of the concrete cover to DRC m Section 7 1 and Figures 11-1 and 11-2A and B
of tiie November 30,2011 version of this CAP
7 1 3 Maintenance of the Phase I Action
Demson will provide a plan for annual inspection, required repairs, and annual documentation of
the condition of the pad in a revised version of the Discharge Mimmization Technology
("DMT") Plan, to be submitted following approval of the CAP by the Executive Secretary The
revised DMT Plan will address
Correcuve AcUon Plan for NiUate 34
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
• frequency of inspection and photographic documentation of the condition of the pad
(annually),
• contents of inspection reports,
• inspection cntena,
• conditions requiring repairs,
• timing of repairs, and
• contents of repair reports
7.1 4 Estimation and Removal of Contaminated Soil Dunng Mill Reclamation
Demson also proposes a future excavation of contaminated soil at the time of Mill site
reclamation, and disposal of the excavated soil m the taihngs cells. To ensure a sufficient surety
amount for reclamation of the known contarmnated soil volume to the depth of bedrock, Denison
proposes to revise the reclamation surety estimate to include a volume of soil of twice the
volume of contaminated soil volume identified m the contamination investigation
The following process will be used to estimate the volume of contaminated soil to be removed
during reclamation Once the total area to be covered by concrete has been detenmned based on
the borehole analyses, the area will be multiplied by the average depth to bedrock, as determined
from the logging of the boreholes
Based on the geologic logging performed dunng the soil probe sampling in the Phase I
Investigation in June, 2011, bonngs number GP-25B and GP-26B m the vicimty of the
ammomum sulfate tanks indicated depth to bedrock of 19 feet and 16 feet, respectively These
values will be included, along with depths detenmned dunng the additional Geoprobe sampling
to develop an average depth to bedrock. This average depth to bedrock will be multiphed by the
area of contamination For conservatism, Demson will double the volume detenmned by the
above method for purposes of the reclamation surety estimate.
Consistent with Section llA(l) of the SCA, Demson provided a revised surety estimate to DRC
on March 4, 2012 The March 4, 2012 surety estimate included an overly conservative estimate
for removal of the contaminated soil volume that was based on
1 The preliminary proposed concrete cover area as depicted in Figure 11-2B
2 An approximate depth to bedrock of 20 feet (1 foot deeper than the maximum depth to
bedrock measured to date dunng the June 2011 investigation)
3 A conservative overestimation factor of 3 times the volume estimated from items 1 and 2
above
Correcuve Acuon Plan for Nitrate 35
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
Following receipt of the additional depth-to-bedrock data and estimated lateral extent of
contanunation data that will be developed from the soil sampling program descnbed above,
Denison will review the March 4, 2012 volume and cost estimate If additional data indicates an
increase of the conservatively estimated soil volume m the March 4, 2012 surety estimate,
Demson will provide a revised volume and cost estimate within 60 calendar days following
issuance of the Consent Order contemplated in Section 11 E of the SCA
The March 4, 2012 surety estimate was based on the overly conservative estimate of 6,000 CY
The current tailings cells hold m excess of 4 million tons (approximately 3 5 imllion CY) of
tailings matenal The anticipated 6,000 CY volume from the ammonium sulfate soil excavation
IS msigmficantly small compared to the total current volume disposed of m the tailings system
As discussed above, following receipt of the data on depth-to-bedrock and lateral extent of
contanunation, Denison will revise the estimated volume and surety estimate accordingly Even
if the excavated soil volume were to increase by several factors following receipt of the data, it
will still be insignificantly small relative to the total volume of the tailings and the total
anticipated reclamation volume for the Mill site
7.2 Phase II Description and Rationale
Phase II consists of three active components and one passive component The active components
are
1. Removal of mtrate mass from the perched zone as rapidly as is practical by pumping
from wells located in areas having high mtrate concentrations, relatively high
productivities, or both
2 Perched zone water level and mtrate momtonng to assess changes m nitrate
concentrations withm the plume, venfy the location of the plume boundary over time,
and estimate hydrauhc capture zones A general lowenng of mtrate concentrations withm
the plume is expected as a result of Phase II operation
3 Abandonment of TWN-senes wells not needed for implementation of item 2
Pumped water will be disposed m the tailings cells In addition, all samples analyzed for nitrate
will also be analyzed for chlonde
The passive component consists of relying on natural attenuation to reduce nitrate
concentrations Physical mechamsms that will reduce nitrate concentrations include processes
such as hydrodynarmc dispersion, and dilution via imxing with nitrate-free recharge and low
mtrate waters outside the plume Neither biologically mediated decomposition of nitrate nor
abiotic chemical decomposition are expected to be sigmficant mechamsms m reducing nitrate
Correcuve Action Plan for Nitrate 36
White Mesa Uranium Mill Near Blandmg, Utah
Revised NiUate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
concenti-ations because the majonty of the perched water is likely aerobic and unsuitable for
rapid decomposition of either chloroform or mtrate The persistence ot chloroform and the
persistence of mtrate associated with the chloroform plume are consistent with predominantly
aerobic conditions The presence of iron oxides withm the perched zone in most of the site
bonngs is also consistent with aerobic conditions
As discussed m HGC (2007) chloroform daughter products, such as dichloromethane (DCM),
have been detected but at low concentrations The persistence of chloroform and the low
concentrations of daughter products imply relatively low rates of chloroform degradation Owing
to Its relatively high oxidation state, chloroform would be expected to degrade relatively rapidly,
yielding higher concentrations of daughter products such as DCM, under pnmanly anaerobic
conditions.
That chloroform daughter products have been detected suggests that conditions are locally
favorable for anaerobic degradation The presence of carbonaceous matenal in many of the site
bonngs and the presence of pynte in most of the bonngs suggests that at least local anaerobic
conditions favorable to degradation of chloroform and nitrate exist The formation hosting the
perched zone was likely anaerobic in the past, and conducive to the preservation of carbonaceous
material and the formation and preservation of pynte, but, at least at some areas of the site, is
now mainly aerobic with pynte oxidizing to iron oxide The oxidation of pynte is hkely
enhanced near perched wells which provide a condmt for oxygen to the perched zone The
oxidation of pynte in the formation has not been substantiated with quantified core analysis,
however, Demson is currently undertaking a separate study to evaluate the amount and
distnbution of pynte in the formation as part of a separate investigation into generally decreasing
pH trends at the Mill site
Wherever conditions may be favorable to anaerobic degradation, the actual degradation rates of
nitrate from either abiotic or biologically mediated degradation may be, m fact, larger than
anticipated, which will be favorable for removal of mtrate from the perched zone However,
Demson is not relying on either abiotic or biologically mediated degradation as important
removal mechamsms
Furthermore, mtrate is not expected to be retarded by adsorption onto aquifer matenals because
of Its high solubility and negative charge The combination of pumping, hydrodynamic
dispersion, and dilution by recharge are expected to be effective considenng that less than an
order of magnitude reduction in concentration is needed to reduce the highest detected mtrate
concenti-ations withm the plume (approximately 69 mg/L) to the target of 10 mg/L The
Correcuve AcUon Plan for NiUate 37
White Mesa Uranium Mill Near Blanding, Utah
Revised NiUate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
downgradient portion of the plume, defined by MW-30 and MW-31, will require reduction in
concentration by only a factor of two to meet the 10 mg/L goal
In general. Phase n is expected to function in a manner sinular to ongoing chloroform removal
from perched water at the site. Constmction and operation will be sinular to the chloroform
pumping system which consists of five wells (MW-4, MW-26, TW4-4, TW4-19, and TW4-20)
located within the chloroform plume that are pumped as continuously as practical and at rates
that are as large as practical Water from those wells is disposed in the tailings cells
The mti-ate pumping system will consist of four wells TW4-22, TW4-24, TW4-25, and TWN-2
(Figure 1-2) Water will be pumped from these wells as continuously as practical and at rates as
high as practical These wells were selected for pumping because 1) they are located m middle to
upgradient areas of the plume having the highest mtrate concentrations and will minimize the
downgradient imgration of these high concentrations, 2) they are expected to have productivities
siimlar to the chloroform pumping wells, 3) pumping these wells is not expected to enhance the
downgradient migration of chloroform, and 4) they are temporary chloroform (TW4-senes) or
mtrate (TWN-senes) investigation wells and converting them to pumping wells will not impact
tailings cell point of compliance monitonng under the Mill's Groundwater Discharge Permit
("GWDP")
Pumping these wells is expected to remove mtrate mass from the perched zone as rapidly as
practical, and flatten hydraulic gradients within the plume to reduce rates of downgradient
imgration and allow natural attenuation to be more effective Furthermore, the depression of the
water table resulting from pumping in the upgradient portion of the plume will reduce interaction
between the perched water and any residual shallow vadose zone sources that may exist As a
result plume imgration is expected to be imnimal or cease once Phase II is implemented
Currently the plume appears to be changing very slowly Figure 9-2 compares the extents of the
nitrate plume m the third quarters of 2010 and 2011 Over this penod, the plume appears to be
relatively stable, having expanded shghtly m some areas and contracted slightly in others The
apparent stability of the plume is likely the result of the generally low hydraulic conductivities of
the perched zone, and ongoing pumping within the adjacent chloroform plume Implementation
of Phase II is expected to further reduce or halt downgradient nugration and to reduce
concentrations within the plume If ongoing momtonng indicates the plume continues to rmgrate,
then contingencies will be implemented
As discussed above, the productivities of the proposed nitrate pumping wells are expected to be
similar to those of the chloroform pumping wells The transnussivities at proposed mtrate
pumping wells TW4-22, TW4-24, and TW4-25 are estimated to be between those of chloroform
Correcuve AcUon Plan for NiUate 38
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
pumping wells MW-26 and TW4-19, and the transnussivity at TWN-2 is estimated to be about
one thu-d that of chloroform pumping well TW4-20 (Table 4) Therefore, the long-term
productivities of TW4-22, TW4-24, and TW4-25 are expected to be between those of MW-26
and TW4-19, and the long-term productivity of TWN-2 is expected to be about one third that of
TW4-20 Although expected pumping rates at TWN-2 will be relatively low, the high
concentrations detected at that well will result in relatively high mtrate removal rates. Pumping
at TWN-2 IS expected to reduce or eliminate the apparent residual perched water mound at that
location As the mound is depleted, the productivity of TWN-2 is expected to dimimsh
However, continued operation of TWN-2, even at low average extraction rates, is expected to be
beneficial.
The potential interaction of the chloroform plume with the nitrate pumping system is of concem
Figure 10 shows the locations of the mtrate and chloroform plumes as of the third quarter of
2011 The chloroform plume is located generally east-southeast of the nitrate plume, but the
plumes mingle in tiie vicimty of TW4-19, TW4-20 and TW4-22 (northeast comer of tailings Cell
#2) Pumping the proposed mtrate wells will impact chloroform migration to some extent, and
any pumping that enhances downgradient migration of chloroform is undesirable It is expected
that pumping the proposed wells will at most draw chloroform cross-gradient to the west-
northwest However, pumping of any wells to the southwest of the chloroform plume (such as
MW-30 and MW-31) would have the undesirable impact of enhancing the downgradient
migration of chloroform, and is not considered to be an option Furthermore, converting MW-30
or MW-31 to mtrate pumping wells would degrade tihie usefulness of these wells for taihngs cell
point of compliance momtonng under the GWDP
Data collected dunng Phase II monitonng will be used to evaluate containment and hydraulic
control of the nitrate plume The data will be used to estimate the extent of hydraulic capture (the
"capture zone"), and to calculate mtrate mass removal rates by pumping
Hydraulic containment and control will be evaluated in part based on water level data (in the
same fashion as for the chloroform pumping system) and in part on concentrations m wells
downgradient of pumping wells TW4-22 and TW4-24 Bounding stream tubes defimng the
capture zone of mtrate pumping wells will be generated from the knged quarterly perched water
level data Hydraulic containment and control based on water level data will be considered
successful if the entire mtrate plume upgradient of TW4-22 and TW4-24 falls withm the
combined capture of the mtrate pumping wells
MW-5, MW-11, MW-30, and MW-31 are located downgradient of TW4-22 and TW4-24 MW-
30 and MW-31 are within the plume near its downgradient edge and MW-5 and MW-11 are
Correcuve AcUon Plan for NiUate 39
White Mesa Uramum Mill Near Blanding, Utah
Revised Nitrate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7,2012
outside and downgradient of the plume Hydraulic control based on concentration data will be
considered successful if the concentirations of mti-ate in MW-30 and MW-31 remain stable or
dechne, and concentrations of mtrate m downgradient wells MW-5 and MW-11 do not exceed
the 10 mg/L standard
Demson will calculate the capture zones after four quarters of water level measurements have
been taken, and will include the calculations, with figures, in the next quarterly mtrate
monitonng report. Numencal and/or analytical models will be used if needed to assist in
evaluating the data and estimating natural attenuation
It IS expected that the four pumping wells, in combination with the existing chloroform pumping
wells, will adequately capture the nitrate plume, such that concentrations of mtrate in excess of
the 10 mg/L standard are not expected to rmgrate beyond the current boundanes of the plume
Based on expenence from the chloroform pumping results to date, it is expected that the capture
zone from the four nitrate pumping wells will, by themselves extend upgradient to capture the
entire plume north of TW4-22 and TW4-24 as well as more than 400 feet downgradient of TW4-
22 and TW4-24 For example, the downgradient extent of the combined capture zone of
chloroform pumping wells MW-26, TW4-19, and TW4-20 (Figure 12) extends more tiian 400
feet downgradient of MW-26 The capture zone from the four mtrate pumping wells alone is
expected to likewise extend at least 400 feet southwest of TW4-22 and TW4-24, encompassing
by themselves approximately three quarters of tiie plume (Figure 13) However, the proportion of
the mtrate plume under hydraulic capture is expected to be larger than this estimate as the mtrate
capmre zone merges and is enhanced by the chloroform capture zone The result is that either
complete hydraulic capture will be achieved, or if not achieved, concentrations of mtrate m
excess of 10 mg/L are not expected to migrate beyond the current boundanes of the plume As
discussed above, hydraulic control will be considered successful if the concentrations of mtrate
m MW-30 and MW-31 remain stable or decline and concentrations of nitrate m downgradient
wells MW-5 and MW-11 do not exceed the 10 mg/L standard
The mtrate plume is defined as that portion of the perched aquifer that has a concentration of
mtrate in excess of 10 mg/L. In evaluating whether the pumping system has contained and
controlled the plume, the proper parameter to evaluate is therefore whether the 10 mg/L
boundary has moved beyond the currently defined plume boundary MW-5 and MW-11
presentiy do not exceed the 10 mg/L Groundwater Quality Standard, that is, they are outside the
currentiy defined plume, and act as bounding wells for the plume So long as they continue to be
less than or equal to 10 mg/L they will remain as bounding wells outside of the plume, and the
plume will not have expanded
Correcuve Acuon Plan for Nitrate 40
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate CorrecUve Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
It IS possible that there may still be some movement of impacted water (i e , there may not be
complete hydraulic capmre), but so long as that movement of water does not cause the
concentration m any downgradient well to exceed 10 mg/L, the plume itself will not have
expanded and adequate hydraulic control will have been demonstrated As a result, it is possible
that there may be some future impact on MW-5 and MW-11, even though the plume has not
expanded However, any impacts on MW-5 and MW-11 will be momtored to ensure that the
concentrations m those wells, if they do increase over time, do not exceed 10 mg/L If the
concentration of mtrate m either or both of those wells increases above 10 mg/L, then the plume
will have expanded and plume capture will not have been successful. Further actions, such as
modeling or the addition of more mtrate pumping wells, would need to be investigated at that
time Because numerous momtonng wells currentiy exist downgradient of MW-5 and MW-11
(i e , MW-35, MW-36, MW-37, MW-15 and MW-14 as a fu-st line of defense, and beyond tiiat
line, MW-17, MW-03, and MW-20), existing wells would continue to bound the plume, and
there would be no chance that the plume could expand beyond the downgradient edge of the
Mill's existing tailings cells, without being detected and without ample time to institute further
nutigative actions
If mtrate concentrations in any of the wells exceed their respective Ground Water Compliance
Lmuts ("GWCLs") listed in Table 2 of tiie current Permit, which are less than 10 mg/L, then
Denison will provide notification to the Executive Secretary, and sampling frequencies for the
wells will be accelerated per the White Mesa Mill GWDP Part G.l
7 2 1 Weil Abandonment
Currentiy there are 19 TWN-senes wells that were installed for the investigation of mtrate at the
site Wells m the vicimty of the mtrate plume will be retained for monitonng TWN-senes wells
located north-northeast of TWN-18 are not needed for this purpose and are therefore selected for
abandonment Wells proposed for abandonment are TWN-5, TWN-8, TWN-9, TWN-10, TWN-
11, TWN-12, TWN-13, TWN-15, and TWN-17 Wells to be retained for mti-ate and chlonde
momtonng, as well as field collection parameters (including water level measurements) per the
approved field collection form, are TWN-1, TWN-2, TWN-3, TWN-4, TWN-7, and TWN-18
The foregoing wells will be abandoned withm one year from the date of approval of this CAP, in
accordance with applicable regulations (State of Utah Administrative Rules for Water Wells R655-4-
14) Although not needed for nitrate plume momtonng, wells TWN-6, TWN-14, TWN-16, and
TWN-19 will be retained for water level momtonng only, to provide ongoing water level data for
the northeast portion of the site
Correcuve Action Plan for Nitrate 41
White Mesa Uranium Mill Near Blandmg, Utah
Revised Niuate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7 2012
A well abandonment report will be submitted to the Executive Secretary withm 15 months after
tiie date of approval of this CAP
7 2 2 Groundwater Pumping System
The Phase II corrective action groundwater pumping system will consist of wells TW4-22, TW4-
24, TW4-25, and TWN-2 (Figure 1-2) Each well will be equipped witii a Gmndfos Senes SQE
1x200-240 Volt, 6 2 Amp submersible pump or the equivalent To prevent damage to the pumps,
each will operate on a cycle that allows pumping only when sufficient water is present in the
well The capacity of each pump will be greater than the sustainable pumping rate for each well
Therefore, the average amount of water pumped from each well will be, m general, the
maximum practical These wells were selected for pumping because they are located in areas of
the perched zone having both high nitrate concentrations and relatively high transnussivities that
allow relatively high rates of mass removal, and because they are not expected to have a negative
impact on chloroform imgration from the adjacent chloroform plume
Water pumped from each well will be routed by inch high-density polyethylene Dnsco
discharge lines, comparable to the transfer lines in the chloroform pumping system, to the
tailings cells for disposal. A schematic drawing of the transfer piping system is provided in
Figure 11-5 The discharge line near each wellhead will be equipped with an m-Ime Carlon Vi'
flow meter/totahzer (or equivalent) The flow meter/totalizer will be housed m an insulated
wooden box with a heat source to prevent freezing Readings from each totalizer will be used to
report quarterly pumped volumes and average pumping rates
Operation of the mtrate wellfield will be similar to that for the chloroform wellfield The
contingencies descnbed in Section 8 will be implemented should mtrate mass removal rates drop
significantly due to losses in well productivity
As mentioned above, water pumped from the nitrate pumping system will be transferred to the
tailings cells for disposal If momtonng of any tailings cell indicates an exceedance in a leak
detection system ("LDS") parameter regulated by the Mill's GWDP, or the Best Available
Technology ("BAT") or Discharge Mimmization Technology ("DMT") Plans, Demson will
manage the response to LDS parameter exceedance consistent with the requirements of the
GWDP or appropnate BAT or DMT Plan The relatively low flow rates of the groundwater
pumping systems, compared to the flow rates of process solutions and wastewaters managed in
the taihngs system, allow for rerouting of taihngs cell solutions and adjustment of cell solution
levels without interruption of the chloroform or mtrate pumping programs
Corrective Acuon Plan for Nitrate 42
White Mesa Uramum Mill Near Blanding, Utah
Revised NiUate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7,2012
Demson will prepare an Operation and Maintenance ("O&M") Plan for Executive Secretary
approval which, like the Chloroform Program Operations and Maintenance Plan will address
operations (including wmterization procedures), maintenance (including inspection forms and
response to and documentation of system failures), monitonng, and data reporting The O&M
Plan will be subnutted per the schedule in Table 1
7 2 3 Water Level Monitonng
Water levels will be momtored weekly in each of the four mtrate pumping wells Water levels in
the remaimng wells listed in Table 3 will be monitored monthly for the first twelve months after
commencement of Phase n pumping, and thereafter quarterly Depths to water will be measured
using an electnc water level meter in the same way they are currently collected Hydraulic
capture zones will be estimated from water level contour maps generated quarterly from the
water level data, with the first capture zones estimated after twelve months of data have been
obtained The contingencies descnbed in Section 8 will be implemented should the proportion of
the remaimng mtrate plume that is under hydraulic capture shrink sigmficantly
7.2 4 Water Quality Monitonng
Pumping wells TW4-22, TW4-24, TW4-25, and TWN-2, and tiie otiier wells hsted m Table 3,
will be momtored quarterly Sampling and analytical procedures will be the same as currentiy
employed for the mtrate momtonng as descnbed m the quarterly momtonng reports submitted
by Demson to DRC and as descnbed in the most cunent, DRC-approved White Mesa Mill
Groundwater Momtonng Quality Assurance Plan ("QAP") Each well will be sampled for the
following constituents with respect to momtonng the mtrate plume.
• Chlonde
• Nitrogen, Nitrate + Nitnte as N
• pH
• Temperature
Dissolved oxygen was not included in the Plan due to unique conditions at White Mesa The
required purge when sampling monitor wells at the site and low hydraulic conductivity in the
perched aquifer causes slow recharge to the well bore after purging This slow recharge allows
oxygen to diffuse into the groundwater as it enters the well bore rendering any dissolved oxygen
measurement umehable
Demson has also assessed the need for analyzing data from selected on site wells for other
groundwater quality parameters that could be relevant to this Plan, and has concluded that the
Correcuve Acuon Plan for Nitrate 43
White Mesa Uramum Mill Near Blandmg, Utah
Revised NiUate CorrecUve Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
existing groundwater momtonng m existing GWDP compliance wells is adequate, and that no
further constituents, other than nitrate and chloride m the TWN wells, need be added to any wells
at the site, for the reasons discussed below
The Mill IS the subject of an ongoing groundwater compliance monitonng program, which
momtors the complete list of constituents regulated in Table 2 of the GWDP If any contanunant
sources, whether or not associated with the mtrate plume, reach levels of concem m
groundwater, they will be detected m the GWDP compliance momtonng program It is therefore
not necessary for the nitrate corrective action to attempt to monitor the same constituents which
are adequately momtored under the existing GWDP program
Further, since the Plan provides a mtrate plume pumping program designed to bound and control
the known contanunation, any other constituents present within the mtrate plume, related to
mtrate as precursors or byproducts or otherwise, will also be capmred by the pumping system
Quarterly reports will be prepared that contain the same elements of the current chloroform
corrective action momtonng reports subnutted by Denison to DRC Specific information
elements to be included m the reports are listed in Sections 10 2 3 and 10 2 6
Existing mtrate and chlonde momtonng will continue m each of the other momtonng wells at
the site at the frequency required under the GWDP or the chloroform investigation, as the case
may be Mamtaimng the current quarterly frequency at the closest downgradient well MW-11
and semi-annual frequency at the next-closest downgradient well MW-5 is reasonable
considenng the apparent stability of the plume at MW-30 and MW-31 and the hydraulic
conductivity at MW-5 (3 5 x 10"^ cm/s) which is nearly three orders of magnitude lower than at
MW-11 (14 X 10"^ cm/s)[HGC, 2007] The sampling frequency for MW-5 and MW-11 was
established under the GWDP based on the velocity of flow m the perched aquifer at these
locations More frequent momtonng was considered inappropnate due to the low flow rates and
the potential to sample the same water or similar water m consecutive sampling events at eacji
well
Should concentrations within the plume begin to generally increase (disregarding short-term
fluctuations), or the plume boundanes begin to expand, the contingencies discussed in Section 8
will be implemented
7.2 5 Reporting
Reporting is proposed to occur quarterly, using a format and content similar to the quarterly
chloroform momtonng reports submitted by Demson to DRC The quarterly reports will include
the following details ~
Correcuve Acuon Plan for Nitrate 44
White Mesa Uranium Mill Near Blandmg, Utah
Revised Niuate CorrecUve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
1 calculation of quarterly nitrate mass removed by pumping,
2 companson ot the current areal extent of the nitrate plume from the latest quarter with the
latest quarter of the previous reporting penod, and
3 discussion of any contingencies to be implemented
7.3 Phase III
Following the collection of 5 years of performance data from Phase n activities, Demson will
use the data to perform an evaluation of the Phase II program The data collected dunng the 5-
year operation may be used for any or all of the following assessments
a) Estimate the rate of mtrate plume remediation (e g in terms of percent mass reduction
and/or concentration reduction per year) If the rate of plume remediation can be
estimated with sufficient certainty, Demson may be able to project a timeline for
remediation through the continued implementation of Phase II tiiat will allow appropnate
adjustments to the reclamation surety estimate, or
b) Identify changes to Phase II to improve its effectiveness or accelerate the restoration
tunelme, or
c) Identify whether Phase III activities, including application for an ACACL may be
necessary in lieu of, or in combination witii. Phase II activities
Phase in may be implemented at the discretion of Demson at any time (including pnor to five
years) if Demson determines that continuation of Phase II is not necessary or appropnate. If
Demson decides to implement Phase HI, Demson will submit a revised CAP to the Executive
Secretary for approval, which incorporates Phase HI Phase II will continue until Phase HI is
approved by the Executive Secretary
If implemented. Phase IH will consist of a transport assessment, a hazard assessment, and an
exposure assessment along with a corrective action assessment including an evaluation of best
available remedial technologies Selection of a technology for implementation will be based on
an evaluation whether the technology will remediate contamination to as low as is reasonably
achievable, if the 10 mg/L standard is not reasonably achievable One possible outcome of these
evaluations could be an application for altemate corrective action concentration liimts
("ACACL") As requured by UAC R317-6-6 15(G), the proposed ACACL must be protective of
human health, and the environment, and must utilize best available technologies. If an ACACL is
proposed, the revised CAP will include the information required, under UAC R317-6-6 15(G),
and any ACACL would require the approval of the Utah Water Quality Board
Correcuve AcUon Plan for NiUate 45
White Mesa Uramum Mill Near Blanding, Utah
Revised NiUate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
The transport assessment will identify any data gaps that exist and develop work plans to collect
any data needed to support hydrologic and geochemical modeling Such modeling will consist of
appropriate quantitative models to predict flow paths, travel times, and potential points of
exposure of mtrate contarmnated groundwater Any potential geochemical reactions or other
attenuation mechamsms will also be identified The transport assessment will inform the hazard
assessment and the exposure assessment
The hazard assessment will identify the risks and hazards to human health and the environment
associated with mti-ate to determine whether an ACACL should be proposed, if the subsequent
exposure assessment concludes that an exposure is reasonably likely ^
The purpose of the exposure assessment is to evaluate the potential harm to human health and the
environment from the hazards identified in the hazard assessment The exposure assessment
takes into account site-specific circumstances that may reduce or enhance tiiie potential for
exposure to mtrate This assessment identifies and evaluates exposure pathways, and provides
forecasts of human and environmental population responses, based on the projected constituent
concentrations, and available information on the chenucal toxicity effects of the constituents
The assessment also addresses the underlying assumptions, variability, and uncertainty of the
projected health and environmental effects Exposure pathways are identified and evaluated
using water classification and water use standards, along with existing and anticipated water
uses
The corrective action assessment consists of a review of ground-water conective action
alternatives in conjunction with the hazard assessment and the exposure assessment Past,
current, and proposed practicable corrective actions will be identified and evaluated against the
costs and benefits associated with implementing each corrective action alternative If ACACLs
are identified as the proposed alternative, the corrective action assessment will demonstrate that
the proposed ACACL is as low as is reasonably achievable, considenng practicable corrective
actions, and is therefore conservative and cost- effective, and would be granted with good cause
A pnncipal way of demonstrating this is by estimating and companng the benefits imparted by a
corrective action measure against the cost of implementing that measure
7 3 1 Water Level and Water Quality Monitonng
Water level and water quality momtonng plans will be proposed m the revised Phase III CAP
pnor to implementation of any proposed corrective action alternative
Correcuve Action Plan for Nitrate 46
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
8. ASSESSMENT OF CORRECTIVE ACTION AND PROTECTION OF
PUBLIC HEALTH AND THE ENVIRONMENT AND CONTINGENCY
PLAN
The effectiveness of Phase II of the corrective action will be assessed based on the following
cntena
1 stability of plume boundanes
2 concentration and mtrate mass trends within the plume
3 nitrate mass removal rates resulting from pumping, and
4 stability of capture zones
Plume boundaries and capture zones will be considered stable, and containment and hydraulic
control of the mtrate plume effective, if concentrations of mtrate m excess of the 10 mg/L
standard do not migrate beyond the current boundanes of the plume The portion of the plume
downgradient of pumping wellsTW4-22 and TW4-24 is currentiy defined by MW-30 and MW-
31, which are located within the plume at its downgradient edge, and MW-5 and MW-11 which
are located outside and downgradient of the plume Hydrauhc capture will be considered
successful if the combined capture zone of the mtrate pumping wells extends upgradient to
capture the entire plume and if concentrations of mtrate m MW-30 and MW-31 remain stable or
decline and concentrations of mtrate in downgradient wells MW-5 and MW-11 do not exceed the
10 mg/L standard If nitrate concentrations in any of the wells exceed their respective GWCLs
listed in Table 2 of the current Pemut, which are less than 10 mg/L, then Denison will provide
notification to the Executive Secretary and sampling frequencies for the wells will be accelerated
per the White Mesa Mill GWDP Part G LThe Contingency Plan schedules for each of the
fore^omg cntena are set out in the Sections 8 1 through 8 4 as applicable
The cntena for assessment of the effectiveness of Phase III of the corrective action, if
undertaken, will be detenmned once the elements of Phase HI have been developed As
discussed in Section 3 2 3, Phase EQ will be undertaken at a later date only after public
participation and Executive Secretary approval Phase IE may include, but is not himted to
continuation ^of Phases I and II activities alone or in combination with momtored natural
attenuation, evaluation of additional remediation and momtonng technologies/techmques,
determination of any additional hydrogeologic charactenzation, groundwater contaminant travel
times and directions, detemunation of ultimate points of exposure to the pubhc and/or wildlife,
appropnate nsk analysis, a cost/benefit analysis, and the possible development of and petition to
the Board for altemate corrective action concentration limits pursuant to UAC R317 -6-6 15 (G)
Correcuve Acuon Plan for NiUate 47
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
This CAP does not specify the details of Phase IH, at this time A Phase III preliminary plan and
schedule for the evaluation of alternatives, for the completion of any further studies, analyses,
applications and petitions, and for the ultimate definition of Phase III, may be proposed by
Denison at a later date, after completion of such studies and evaluations, followed by submittal
of a proposed CAP revision to the Executive Secretary
8.1 Stability of Plume Boundary (Phase II)
The stability of the plume boundary, based on Phase n CAP monitonng activities discussed in
Sections 7 and 10, will be used to deterrmne the following
• Whether any additional pumping wells are needed, and
• The need to reevaluate the Phase II strategy
Under conditions where the plume boundanes remain stable or contract, no additional pumping
wells will be needed, and no reevaluation of Phase n will be needed Under conditions where the
plume imgrates, with the concurrence of the Executive Secretary, one or more additional
pumping wells will be added, if suitable wells are available, to slow the imgration rates and/or to
bnng more of the plume under hydraulic capture. The installation of additional downgradient
momtonng wells is not anticipated because two lines of wells currently exist downgradient of the
mtrate plume Any such additional pumping wells will be added in accordance with a schedule to
be approved by the Executive Secretary If the plume continues to imgrate, or suitable additional
pumping well locations are not available, then Phase II will be reevaluated, which may include
commencement of Phase HI Analytical or numencal models will be used if needed in the
reevaluation to develop a response The reevaluation process will be completed in accordance
with a schedule to be approved by the Executive Secretary
Any mtrate concentrations above 10 mg/L associated with the chloroform plume, that are not
part of the mtrate plume shown m Figure 1-2, will be included m the remedial action for the
chloroform plume
8.2 Concentration and Nitrate Mass Trends within the Plume (Phase II)
Concentration changes within the plume are expected to-be reflective of changes m mtrate mass
within the plume
Changes in mtrate mass within the plume based on concentrations and saturated thicknesses will
be used to determine any need for reevaluation of Phase II Data used to calculate nitrate mass
will utilize analytical and water level data collected from wells, identified m Table 3, through
Phase II CAP monitoring Assuming that the plume boundaries do not expand, that
Correcuve Action Plan for NiUate 48
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
concentirations withm the plume will generally decrease, and that saturated thicknesses do not
increase, the calculated mass of mtrate within the plume is expected to decrease over time The
changes in calculated mass within the plume will be evaluated as follows
1) Calculate a baseline mass for the mtrate plume This calculation will utilize the second
quarter, 2010 concentration data (provided in Table 3) and saturated thickness data within the
area of the knged 10 mg/L plume boundary This data set is appropnate because the second
quarter, 2010 concentration peak at TWN-2 likely identifies a high concentration zone that still
exists but has migrated away from the immediate vicimty of TWN-2
2) Calculate the plume mtrate mass quarterly based on knged mtrate concentrations and
saturated thicknesses (within the knged 10 mg/L plume boundary)
3) After 8 quarters, fit a regression tirend line to the calculated mass values for the plume and
determine whether the mass calculation is mcreasmg, decreasing, or stable
4) Add data quarterly thereafter, recalculate the ti-end line for the plume quarterly, and evaluate
If the mass trend line after eight quarters is flat or decreasing (and the plume boundanes are not
expanding), then Phase II will be considered successful at that time Ongoing quarterly trend
analysis will then indicate whether or not Phase n continues to be successful
If the mass trend hue is increasing after eight quarters, the data will be exaimned to determine if
the increase is the result of increases in concentration at only one or two wells within the plume
that are having an outsize impact on the mass calculation Changes in concentration at individual
wells are expected to result m part from nugration of mtrate toward pumping wells Because of
the potential for mtrate to exist at higher concentrations between existing wells (and to be
undetected at the present time), movement induced by pumping may cause migration of a higher
concentration zone into the vicimty of a particular well, causing a (presumably temporary)
increase in concentration at that well The existence of a higher concentration zone near TWN-2
IS evidenced by the relatively large changes m concentration inTWN-2 from the first quarter of
2010 through the tinrd quarter of 2011 (Table 3). Flucmations m concenti-ation at TWN-2, which
has demonstrated the highest historic concentrations, could result in fluctuations in the mass
calculation that affect the slope or direction of a trend line Similar fluctuations at wells other
than TWN-2 could have the same impact
Correcuve Acuon Plan for Niuate 49
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
The usefulness of the mass-based methodology described above will be reevaluated if needed
based on the 8 quarters of collected data used to establish the initial trend line If the method
provides erratic values of linuted usefulness, or is impacted unduly by the outsized impacts of
one or more wells, a modified or new method will be developed at that time The nature of the
modified or new method will have the benefit of eight quarters,of data to test its usefulness
If the trend in mtrate mass calculations indicates a need to reevaluate the effectiveness of Phase
n, analj^cal or numencal models will be used in the reevaluation if needed to develop a
response The reevaluation process will be completed m accordance with a schedule to be
approved by the Executive Secretary Anticipated responses to this condition would likely
include adding existing or new wells to the pumping network, if suitable well locations are
available, or other measures designed to achieve a more rapid rate of mass reduction If suitable
well locations are not available, then Phase DI will be considered.
8.3 Nitrate Mass Removal Rates Resulting from Pumping (Phase II)
Under conditions where mtrate mass removal rates by pumping drop substantially as a result of
reduced concentrations within the plume, no action will be taken Under conditions where mtrate
mass removal rates by pumping drop substantially as a result of lost well productivities, then an
evaluation of the lost productivity will be undertaken If the lost productivity is determined to be
a well efficiency problem, the inefficient wells will be re-developed or replaced in accordance
with a schedule to be approved by the Executive Secretary. Should the lost productivity be
detenmned to be due to a general reduction in saturated thickness, analytical or numerical
models will be used to evaluate the potential effectiveness of adding existing or new wells to the
pumping network to improve overall productivity, if suitable well locations are available If the
analysis indicates that overall productivity will not improve sigmficantiy by adding wells, or if
suitable well locations are not available, then no action will be taken.
A loss in productivity due to a general decrease in saturated thickness will likely be offset by the
benefits of the reduced saturated thickness First, this condition would indicate that removal of a
substantial amount of nitrate laden water had already taken place Second, the reduced saturated
thickness within the mtrate plume would reduce average hydraulic gradients and reduce the
potential for downgradient migration These factors will be considered in any reevaluation that
may be performed
Correcuve AcUon Plan for NiUate 50
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
8.4 Stability of the Proportion of the Nitrate Plume under Hydraulic
Capture (Phase II)
Under conditions where concentrations of mtrate in excess of the 10 mg/L standard migrate
beyond the current boundanes of the plume, as evidenced by concentrations of mtrate m MW-30
and MW-31 increasing and/or concentrations of nitrate m downgradient wells MW-5 and MW-
11 exceeding the 10 mg/L standard, an evaluation of the factors resulting in this condition will be
undertaken If the condition is determined to result from lost productivity of the pumping wells
due to well efficiency problems, the inefficient wells will be re-developed or replaced in
accordance with a schedule to be approved by the Executive Secretary Should the loss in capture
be detenmned to result from other conditions, then Phase II will be reevaluated, which may
include commencement of Phase III Analytical or numencal models will be used in the
reevaluation if needed to develop a response The reevaluation process will be completed in
accordance with a schedule to be approved by the Executive Secretary
Anticipated responses to tins condition would likely include adding existmg or new wells to the
pumping network to bnng a larger proportion of the plume withm hydraulic capture, if suitable
well locations are available If suitable well locations are not available, then Phase HI will be
considered.
Any mtrate concentrations above 10 mg/L associated with the chloroform plume, that are not
part of the mtrate plume shown in Figure 1-2, will be included m the remedial action for the
chloroform plume
8.5 Phase III
As discussed in Section 3.2 3, Phase IH, if necessary, will be undertaken at a later date only after
public participation and Executive Secretary approval Phase III may include, but is not himted
to: continuation of Phases I and II activities alone or in combination with momtored natural
attenuation, evaluation of additional remediation and monitonng technologies/techmques,
detemunation of any additional hydrogeologic charactenzation, groundwater contaminant travel
times and duections, determination of ultimate points of exposure to the pubhc and/or wildlife,
appropnate nsk analysis, a cost/benefit analysis, and the possible development of and petition to
the Board for altemate corrective action concentration limits pursuant to UAC R317 -6-6 15 (G)
This CAP does not specify the details of Phase in, at this time A Phase III preliminary plan and
schedule for the evaluation of alternatives, for the completion of any further studies, analyses,
applications and petitions, and for tiie ultimate definition of Phase in, may be proposed by
Denison at a later date, after completion of such studies and evaluations, followed by submittal
Correcuve AcUon Plan for NiUate 51
While Mesa Uramum Mill Near Blanding, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
of a proposed CAP revision to the Executive Secretary Until such time, the activities of the
Phase I and Phase 11 remediation will continue as stipulated m the approved CAP
8.6 Permanent Effect of Corrective Action
Phase n. Phase III, and tiie contingencies outiined above (Sections 8 1 through 8 5) are designed
to protect the public health and the envu-onment by contaimng the mtirate plume witiim the site
property boundary and reducing mtirate concentrations within the plume to the concentration
limit of 10 mg/L As concentrations will then continue to be reduced by natural attenuation,
demonsti-ation that the corrective action will have a permanent effect will be based on
appropnate future evaluations
8.7 In-Place Contaminant Control
As discussed in Section 7, the corrective action relies on active and passive sti-ategies to meet
CAP objectives The passive strategy includes m-place contaminant control by reducing nitrate
concentrations via natural attenuation
Corrective AcUon Plan for Nittate 52
White Mesa Uranium MilhNear Blanding, Utah
Revised Nitrate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
9. IMPACTS OF OFFSITE ACTIVITIES
As discussed in Section 7, nitrate will be treated m place by namral attenuation and removed
from the perched zone by pumping Because all pumped water will be disposed onsite in the
tailings cells, there will be no offsite impacts resulting from CAP implementation.
Corrective Action Plan for NiUate 53
White Mesa Uramum Mill Near Blanding, Utah
Revised Nitrate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
Corrective AcUon Plan for NiUate 54
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Correcuve Action Plan redbne Final 05 07 12 Fnl doc
May 7.2012
10. PROPOSED PLUME CORRECTIVE ACTION ACTIVITIES
Phase II and Phase HI corrective action activities and contingencies are discussed in detail in
Sections 7 and 8 These activities are summanzed m Sections 101 and 10 2 below
10.1 Phase I
The Phase I source control action was discussed in Section 7 1, above
10.2 Phase II
Phase II corrective action activities include pumping of wells TW4-22, TW4-24, TW4-25, and
TWN-2, momtonng and maintenance of the pumping system, water level monitonng, momtonng
for mtrate and chlonde, estimation of hydraulic capture, implementation of contingencies as
needed, and reporting
10 2 1 Groundwater Pumping
Wells TW4-22, TW4-24, TW4-25, and TWN-2 (Figure 1-2) will be pumped at tiie maximum
practical rates Pufiiped water will be disposed m the tailings cells The wellfield will be operated
and maintained in the same fashion as the chloroform removal wellfield Momtonng will include
pumping rates and volumes for each well
10 2 2 Water Level Monitonng
Water level momtonng will consist of weekly water level monitoring of pumping wells TW4-22,
TW4-24, TW4-25, and TWN-2, and, for tiie first twelve montiis after approval of this CAP,
monthly momtonng of non-pumped wells MW-27, MW-30, MW-31, TW4-21, TWN-1, TWN-3,
TWN-4, TWN-7, and TWN-18 (Figure 1-2) Thereafter, water level momtonng of those non-
pumping wells will continue quarterly Water level contour maps of the data will be generated
quarterly
10 2 3 Water Quality Monitonng
Water quality momtonng for pumped wells TW4-22, TW4-24, TW4-25, and TWN-2 and all
other wells listed on Table 3 will be quarterly Samples will be analyzed for chlonde, and for
mtrogen (mtrate and mtnte as N) Field parameters pH and temperature will be recorded
(Section 6 2 4) Water quality momtonng for chlonde, nitrate, and field parameters for all other
wells at the site will continue at the frequency required under tiie GWDP or chloroform
investigation, as the case may be
Correcuve Acuon Plan for Nitrate 55
White Mesa Uramum Mill Neir Blanding, Utah
Revised NiUate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
10 2 4 Estimation of Capture Zones
Hydraulic capture zones will be generated from the quarterly water level contour maps m the
same manner as they are currently generated for the chloroform pumping
10 2 5 Estimation of Pumped Nitrate Mass and Nitrate Mass within the Plume
Quarterly estimates of nitrate mass removed by pumping will be made based on cumulative
pumped volumes at each pumped well and nitrate concentrations at each pumped well Quarterly
estimates of the mtrate mass remaining within the plume will also be calculated based on knged
concentrations m wells listed in Table 3 and saturated thicknesses, as discussed in Section 8 2
10 2 6 Reporting
Quarterly reports will be prepared that contain the same elements of the current chloroform
corrective action monitonng reports submitted by Demson to DRC and will include the
following
1 Tabular compilations of groundwater level measured in non-pumped wells over time,
2 Water level data from pumped wells over time,
3 Runmng and cumulative groundwater volumes removed from each pumping well,
4 Calculations and/or spreadsheets documenting quarterly mtrate mass removed by
pumping,
5 companson of the areal extent of the nitrate plume from the latest quarter with the latest
quarter of the previous reporting period, and
6 discussion of any contingencies implemented or to be implemented
10 2 7 Additional Measures
Based on Phase II momtonng, and the cntena discussed in Section 8, contingencies that include
potential installation of additional wells, well rehabihtation or replacement, potential expansion
of the pumping well network, if smtable well locations are available, and reevaluation of the
Phase n strategy and consideration of commencement of Phase III activities will be implemented
as needed Factors that could tngger the implementation of contingencies include 1) expansion of
the plume boundanes, 2) generally increasing nitrate concentrations and calculated mtrate mass
within the plume, 3) reductions in mtrate mass removal rates due to losses in pumping well
productivities, and 4) decreases m the effectiveness of hydraulic capture
Correcuve AcUon Plan for Nitrate 56
White Mesa Uranium Mill Near Blandmg, Utah
Revised Nitrate Corrective Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
10.3 Phase III
As discussed m Section 3 2 3, Phase III, if necessary, will be undertaken at a later date only after
public participation and Executive Secretary approval Phase ni may include, but is not limited
to continuation of Phases I and II activities alone or m combination with monitored natural
attenuation, evaluation of additional remediation and monitonng technologies/techmques,
detemunation of any additional hydrogeologic characterization, groundwater contanunant travel
times and directions, determination of ultimate points of exposure to the public and/or wildlife,
appropnate nsk analysis, a cost/benefit analysis, and the possible development of and petition to
the Utah Water Quality Board for altemate corrective action concentration limits pursuant to
UAC R317-6-6 15(G)
This CAP does not specify the details of Phase IH, at tins time A Phase JR prelmunary plan and
schedule for the evaluation of alternatives, for the completion of any further studies, analyses,
apphcations and petitions, and for the ultimate defimtion of Phase III, may be proposed by
Demson at a later date, after completion of such studies and evaluations, followed by submittal
of a proposed CAP revision to the Executive Secretary Until such time, the activities of the
Phase I and Phase H remediation will continue as stipulated m the approved CAP
Correcuve Acuon Plan for NiUate 57
White Mesa Uranium Mill Near Blandmg, Utah
Revised NiUate Corrective Action Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
Correcuve AcUon Plan for NiUate 58
'White Mesa Uranium Mill Near Blanding, Utah
Revised NiUate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
11. REFERENCES
HGC 2004 Final Report Long Term Pumping at MW-4, TW4-19, and TW4-15, White Mesa
Uranium Mill Near Blanding, Utah Subnutted to Intemational Uranium (USA)
Corporation, Denver, Colorado
HGC 2005 Perched Monitoring Well Installation and Testing at the White Mesa Uramum Mill,
Apnl Through June, 2005 Submitted to Intemational Uramum (USA) Corporation,
Denver, Colorado
HGC 2007a Prehnunary Corrective Action Plan, White Mesa Uramum Mill Near Blanding,
Utah August 20, 2007
HGC 2007b Preliminary Contaimnation Investigation Report White Mesa Uramum Mill Site
Near Blanding, Utah November 20, 2007.
HGC. 2009a Site Hydrogeology and Estimation of Groundwater Pore Velocities m the Perched
Zone White Mesa Uramum Mill Near Blanding, Utah December 29, 2009
HGC 2010 Hydrogeology of the Perched Groundwater Zone and Associated Seeps and Spnngs
Near the White Mesa Uramum Mill Site, Blanding, Utah
INTERA 2009a Source Review Report for Nitrate and Chlonde m Groundwater at the White
Mesa Mill December, 2009
INTERA 2009b Nitrate Contamination Investigation Report White Mesa Uramum Mill Site
Blanding, Utah December 30, 2009
INTERA 2011 Nitirate Investigation Revised Phases 2 tiirough 5 Work Plan August, 2011
Kirby 2008 Geologic and Hydrologic Charactenzation of the Dakota-Burro Canyon Aquifer
Near Blanding, San Juan County, Utah Utah Geological Survey Special Study 123
Kmght-Piesold 1998 Evaluation of Potential for Taihngs Cell Discharge - Mill Attachment 5,
Groundwater Information Report, White Mesa Uramum Mill, Blanding, Utah Submitted
to DRC
TITAN 1994 Hydrogeological Evaluation of White Mesa Uramum Mill Submitted to Energy
Fuels Nuclear
UMETCO 1993 Groundwater Study White Mesa Facihties Blanding, Utah Prepared by
UMETCO Minerals Corporation and Peel Environmental Services
Correcuve AcUon Plan for Nitrate 59
White Mesa Uranium Mill Near Blandmg, Utah
Revised NiUate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
Correcuve AcUon Plan for Nitrate 60
White Mesa Uranium Mill Near Blanding, Utah
Revised Nitrate Correcuve AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
12. LIMITATIONS STATEMENT
The opimons and recommendations presented in this report are based upon the scope of services
and information obtained through the performance of the services, as agreed upon by HGC and
the party for whom this report was originally prepared Results of any investigations, tests, or
findings presented in this report apply solely to conditions existing at the time HGC's
investigative work was performed and are inherentiy based on and hmited to the available data
and the extent of the investigation activities No representation, warranty, or guarantee, express
or implied, is intended or given HGC makes no representation as to the accuracy or
completeness of any information provided by other parties not under contract to HGC to the
extent that HGC relied upon that information This report is expressly for the sole and exclusive
use of the party for whom tins report was onginally prepared and for the particular purpose that
It was intended Reuse of this report, or any portion thereof, for other than its intended purpose,
or if modified, or if used by third parties, shall be at the sole nsk of the user
Correcuve AcUon Plan for Nitrate 61
White Mesa Uranium Mill Near Blanding, Utah
Revised NiUate Correcuve Acuon Plan redbne Final 05 07 12 Fnl doc
May 7, 2012
Correcuve Acuon Plan for NiUate 62
White Mesa Uranium Mill ^ear Blanding, Utah
Revised Nitrate Corrective AcUon Plan redbne Final 05 07 12 Fnl doc
May 7,2012
TABLES
TABLE 1
Nitrate Corrective Action Schedule
STEP OR ACTION PATE
Executive Secretary Issuance of Consent Order Approving Corrective
Action Plan No set date
Commence Corrective Actions Within 30 days of CAP approval
Phase 1
Submit Phase 1 Plan and Schedule for Ammonium Sulfate Corrective
Action 1/1/2012
Submit Revised Reclamation Plan and Financial Surety Estimate for
Phase 1 3/4/2012
Submit Evidence of Adequate Surety for Phase 1
Within 30 days of approval of Phase 1
revised surety estimate
Perform Initial Soil Sampling within 30 days of CAP approval
Perform additional analysis if required Within analytical holding time
Submit analytical data and proposed Sulfate Area Cover design to
Executive Secretary
Within 60 days of receipt of all required
soil sampling data
Construct Ammonium Sulfate Area Cover
within 60 days of receipt of Executive
Secretary approval of design
Submit DMT Plan revisions with concrete pad maintenance and
inspection requirements Within 45 days of CAP approval
Phase II
Submit Revised Reclamation Plan and Financial Surety Estimate for
Phase 1 and 11 Within 60 days of Consent Order
Submit Evidence of Adequate Surety for Phase 1 and 11
Within 30 days of approval of Phase 1
and 11 revised surety estimate
Submit Nitrate Operations and Maintenance Plan Within 30 days of Consent Order
Install Pumps in Wells TW4-22, TW4-24, TW4-25, and TWN-2 Within 30 days of Consent Order
Begin Pumping Wells TW4-22, TW4-24, TW4-25, and TWN-2 Within 45 days of Consent Order
Cease Sampling of TWN-5, TWN-6, TWN-8, TWN-9, TWN-10, TWN-
11, TWN-12, TWN-13, TWN-14, TWN-15, TWN-16, TWN-17, TWN-19 upon issuance of Consent Order
Cease Water Level Monitonng of TWN-5, TWN-8, TWN-9, TWN-10,
TWN-11, TWN-12, TWN-13, TWN-15, TWN-17 upon issuance of Consent Order
Abandon Wells TWN-5, TWN-8, TWN-9, TWN-10, TWN-11, TWN-12,
TWN-13, TWN-15, TWN-17 Within 15 months of Consent Order
Reporting of Monitonng and Pumping Data
as part of ongoing quarterly nitrate
monitonng reports
H \718000\nitrate2011\CAP\PDF Rev Fnl CAP 050412\
Table 1 Nitrate CAP Schedule 05 07 12 xls Table 1 Page 1 of 2 5/4/2012
TABLE 1
Nitrate Corrective Action Schedule
STEP OR ACTION DATE
Submit Capture Zone Maps
In quarterly report after four quarters of
monthly groundwater level data
Submit Well Abandonment Report Within 15 months of Consent Order
After collection of 5 years of Phase II
Evaluate Phase II performance information performance data
Within 180 days of collection of 5 years
Provide Phase il performance report to Executive Secretary of Phase ll data
Phase III
To be determined at discretion of Denison —
H \718000\nitrate2011\CAP\PDF Rev Fnl CAP 050412\
Table 1 Nitrate CAP Schedule 05 07 12 xls Table 1 Page 2 of 2 5/4/2012
TABLE 2
Hydraulic Conductivity Estimates for Wells in the Nitrate Plume Area
Well k (cm/s)^ Method
MW-11 1 40E-03 pumping
MW-27 8 20E-05 ^slug
MW-30 1 OOE-04 /^slug
MW-31 7 10E-05 ^slug
TW4-19 2 50E-04 pumping
TW4-20 5 90E-05 ^slug
TW4-21 1 90E-04 ^slug
TW4-22 1 30E-04 ^slug
TW4-24 1 60E-04 ^slug
TW4-25 5 80E-05 ^slug
TWN-1 1 70E-04 ^slug
TWN-2 1 49E-05 ^slug
TWN-3 8 56E-06 ^slug
TWN-18 2 27E-03 ^slug
Notes
' hydraulic conductivity
^ KGS slug test solution
in centimeters per second
results for automatically logged data
H \718000\nitrate2011\PoreVel\perm xls Table 2 5/4/2012
0)
E
3
O
(0
o .c
tn
CO o
-I ^
QQ (0
D) E,
(0 c _o
(0 i_
c
u c o o
a>
(0
o
CM
CO
o
o
CM
CM
O
o
CM
o
CM
o
o
CM
CO
o
o
CM
CM O
o
CM
CD
CD
to
CD
CM
CM
CM
CO
CM
CM
CM
Oi
CM
00
CO
CO
CO
CO
CO
in
in
CO
CM
i
I
CO
CO
CO
©
I >
C (0 (0 (0 c •= E
CD a>
^ .E ^ u{ g- O) —' E c
J2 -is
" CO c o o a.
CO o
Q.
E o o
'a
n
s
m
i
s
s
i
v
i
(f
t
2
/
d
a
v
)
in o CO c:> CM CO CM CO
H
te
d T
h
i
c
k
n
e
s
s
^
(f
e
e
t
)
o o in CM
CM
CM
CD CM
in
Oi
in in
00
00
CO
[u
r
a
l
oa
i
>
Co
n
d
u
c
t
/d
a
y
)
o
CO CM •«^-
CM CM
o
CO
O
O in
CO CO CO
00 CM CO
CM
o
O O o o o o o o
Hy
d
r
a
u
l
>
c C
o
n
d
u
c
t
(c
m
/
s
)
OO
E
-
0
4
OO
E
-
0
5
70
E
-
0
3
50
E
-
0
4
90
E
-
0
5
30
E
-
0
4
60
E
-
0
4
80
E
-
0
5
49
E
-
0
5
mm 00 CM in •r-in
Hy
d
r
a
i
pe
1 p
u
m
p
i
n
g
1 p
u
m
p
i
n
g
1 p
u
m
p
i
n
g
1 p
u
m
p
i
n
g
1 p
u
m
p
i
n
g
pu
m
p
i
n
g
pu
m
p
i
n
g ,

pu
m
p
i
n
g
pu
m
p
i
n
g
>.
ch
l
o
r
o
f
o
r
n
ch
l
o
r
o
f
o
r
n
r
ch
l
o
r
o
f
o
r
r
r
ch
l
o
r
o
f
o
r
m
fc
3 •
o ] o
XZ <
o
pr
o
p
o
s
e
d
pr
o
p
o
s
e
d
pr
o
p
o
s
e
d
pr
o
p
o
s
e
d
We
l
l
MW
-
4
MW
-
2
6
TW
4
-
4
TW
4
-
1
9
TW
4
-
2
0
TW
4
-
2
2
TW
4
-
2
4
TW
4
-
2
5
1 T
W
N
-
2
CO CO CD
I
•o
5
CO
CO
I
9-c: o c:
•o
ctj
o o
00
X
FIGURES
! / Ceil 4A .
EXPLANATION
RUIN SPRING
i seep or spnng
HYDRO
GEO
CHEM, INC
WHITE MESA MILL SITE PLAN
SHOWING LOCATIONS OF SEEPS AND SPRINGS
APPROVED
SJS
DATE REFERENCE FICURE
05/01/2012 H/718000/niitrate2011/CAP/UTMsitennapsrf 1-1
MW20
TW4 IS
o PIEZ1 e
TWN-1
o
MW-3G
MW-4
EXPLANATION
perched monitoring well
temporary perched monitoring well
perched piezometer
temporary perched nitrate
monitoring weD
perched monitoring well
installed April 2011
perched chloroform extraction well
proposed nitrate extraction well
( ^ approximate area of nitrate > 10 mg/L wildlife pond
HYDRO
GEO
CHEM, INC APPROVED
SJS
SITE PLAN SHOWING PERCHED
WELL LOCATIONS AND 3rd QUARTER, 2011
NITRATE PLUME EXTENT
WHITE MFSA SITF
DATE
05/01/2012 H 7718000/
novl 1/nitrate/nitplume11 v2 srf 1-2
PROPERTY
BOUNDARY
MW22
• S30,
PIE2 1
TWN 4
MW-36
MW-4
EXPLANATION
perched monitoring well showing elevation m feet amsl
temporary perched monitoring well
showing elevation in feet amsl
perched piezometer showing
elevation in feet amsl
temporary perched nitrate monitoring well
showing elevation in feet amsl
perched monitonng well installed Apn\ 2011 showing elevation in feet amsl
perched chloroform extraction well stiovnng elevation in feet amsl
HYDRO
GEO
CHEM, INC
KRIGED TOP OF BRUSHY BASIN ELEVATIONS
WHITE MESA SITE
APPROVED DATE REFERENCE RGURE
SJS 05/01/2012 Hy718000/nov11/bbel/bbelq211v2srf 3
MW22
• 5^50
TW4 1
055S4
TWN4
O =603
MW-36
MW-4
«555
EXPLANATION
perched monitoring well showing
elevation in feet amsl
temporary perched monitoring well ^
sfKwing elevation in feet amsl
perched piezometer showing
elevation in feel amsl
temporary perched nitrate monitonng well
showing elevation in feet amsl
perched monitoring well installed April
2011 showing elevation in feet amsl
perched chloroform extraction well
showing elevation in feet amsl
estimated dry area (kriged
> Brushy Basin elevation > ^'' kriged perched water elevation NOTE MW-4 MW-26 TW4 4, TW4-19 and TW4 20 are pumping wells
HYDRO
GEO
CHEM, INC
KRIGED 3rd QUARTER, 2011 WATER LEVELS
WHITE MESA SITE
APPROVED
SJS 05/01/2012
"^•^ H 7718000/
nov 11 /riitrate/wl0911dv2 srf
TWN-4
MW36
MW-4
EXPLANATION
perched monitonng well showing
saturated thickness in feet
temporary perched monitoring well
showing saturated thickness in feet
perched piezometer showing
saturated thickness in feet
temporary perched nitrate monitoring well
showing saturated thickness in feet
perched monitoring well installed April
2011 showing saturated thickness in feet
perched chloroform extraction well
showing saturated thickness in feet
, - ^ - ^ estimated dry area (kriged
{ , Brushy Basin elevation >
— kriged perched water elevation NOTE MW4 MW 26. TW4-4. TW4-19 and TW4-20 are pumping wells
HYDRO
GEO
CHEM, INC
3rd QUARTER, 2011 SATURATED THICKNESS
WHITE MESA SITE
APPROVED
SJS
DATE REFERENCE
05/01/2012 Hy718000/
novl 1/bbelev/sat0911 v2 srf
TWN-4
MW-36
•if-1 0
MW4
»7
EXPLANATION
perched monitoring well showing
depth in feet
temporary perched nranitonng well
showing depth in feet
perched piezometer showing
depth in feet
temporary perched nitrate monitoring well
showing depth in feet
perched monitonng well installed Apnl
2011 shounng depth in feet
perchedchloroform extraction well
showing depth in feet
NOTE MW 4, MW-26. TW4-4 TW4-19 and TW4 20 are pumping wells
HYDRO
GEO
CHEM, INC
3rd QUARTER, 2011 DEPTHS TO WATER
WHITE MESA SITE
APPROVED
SJS 05/01/2012 H/718000/nov11/
bbelev/dtw0911 v2 srf
MW11
• NO
TW4 1
Ose
TWN 1
• 05
MW36
02
MW4
# 49
EXPLANATION
perched monitoring well showing
concentration in mg/L
temporary perched monitoring well
showing concentration in mg^
perched piezometer showing
concentration in mg/L
temporary perched nitrate monitoring well
showing concentration in mg/L
perched nnnitoring well installed April
2011 showing concentration in mg/L
chlorofrom extraction well
shovnng concentration in mg/L
NOTE MW-4, MW-26, TW4 4 TW4 19 and TW4-20 are pumping wells
HYDRO
GEO
CHEM, INC
KRIGED 3rd QUARTER, 2011 NITRATE (mg/L)
(NITRATE + NITRITE AS N)
WHITE MESA SITE
APPROVED
SJS 05/01/2012 ''^ Hy718000/
novl 1 /nitrate/nit0911 v2 srf
•mm/ V / /
/'''"^\GP...:ii ^
c ' \/ "USE*
GP'jei > ' liipviiiivpini!!!
TO
1-. X
V' • • • -A
,v- • • ' .• • ;o GP--45I ^\ ,vGP-47i . '.^
! 0 •
\ • GP 07i
CBiEjaJl • 'G'os*' ( GP-;,i3r '^'-''P* '.V. ;
300 150 0 300
HI Feet
A' SpifnsfSeep It Jl
^• Surface.VStatar:' .fe j
Chtoroform Monitortng V\tel|^ < n,
0 ' NHrats Monitonng WBU
Leid^ HsIcI (currvnliy In op«iiiiQit^
Potefitial MKI Site Sot^l^'
GeoprobeBotfno^
other Potential Nitrate m^ s
Chlqridft Source - deoprab
Inaeosssttto p'oJsnilallinD'Srt^Sour
No Geopfofie, Boring' '.^i.'' 4
Mancos ShateTt^icknest Combur{reet).'
Source(s) Aenal - Utah GIS Portal wetisite dated 2009
Wells-HGC Inc May 2008 report
Figure 8
Potential Nitrate Source Areas
and Geoprobe Locations Showing
ttie Thickness of the Mancos Shale
S Pto)trM..l.-C 00 01 OC Dcn-sen Min ^ G S\.-iiar!loc;sMHiatcP5po(r20I2i2X_na-.c
Nitrate Concentrations in IVIW-30
25
20
115
I 10
0
Jan-04 May-05 Oct-06 Feb-08 Jul-09
Sample Date
1 \ 1
Nov-10 Apr-12 Aug-13
Nitrate Concentrations in MW-31
35
30
3 25
% 15
%m
10
5
0 I 1 i 1 1 1 1
Jan-04 May-05 Oct-06 Feb-08 Jul-09 Nov-10 Apr-12 Aug-13
Sample Date
HYDRO
GEO
CHEM, INC.
NITRATE CONCENTRATIONS IN MW-30 AND MW-31
Approved
SJS
Date Author Date Rie Name
2/23/12 2/23/12 RH FX2
Figure
9-1
H \718000\nitrate2011\CAP\Figure 9-1 xls Figure 9-1
TWN 1
MW36
MW4
SCALE IN FEET
EXPLANATION
perched monitoring well
temporary perched monitoring well
perched piezometer
temporary perched nitrate monitoring well
perched monitoring well installed April 2011
perched chloroform extraction well
3rd quarter 2010 nitrate
,y plume boundary
HYDRO
GEO
CHEM, INC
COMPARISON OF NITRATE PLUME BOUNDARIES
3rd QUARTER 2010 AND
3rd QUARTER 2011
APPROVED
SJS 05/01/2012
Hy718000/
novl 1/nitrate/nitcompv2 srf 9-2
6 #
ince=;A
GP-25B-5 5-6 5 6/8/2011 10^0 1530
GP-25B-13-14 6/8/2011 1350 27 6
GP-25B-13-14D 6/8/2011 1270 27 3
GP 25B-ia-19 6/8/2011 1620 1S.3
GP-26B-4 5-5 5 6/9/2011 1,190 5 05
6P-26B-10-11 6/9/2011 912 0 301
GP-26B-15-16 6/9/2011 X590 6Z3
Source(s} Aenal - Utah GIS Portal website dated 2009
Wells-HGC Inc May 2008 report
Figure 11-1
Ammonium Sulfate Contamination
S Proj'cls LC CO -01 00 Den-scn Mmsi G S\Ti3pdocsV-) tratePsporrZ-'^ll 228rrrr-cn[u-nSJ a mxa
m
o
5 s 5
S CO C)
O -I
Figure 11-3
Fire System Schematic
n
{-1
It
r
I 0
I I
ri-vvl-r:
^3
IA
I s i
\ If
T »0* if
•it
'Past,
APPENDIX A
HYDROGEOLOGIC CROSS SECTIONS
TWN 1
• 05
MW36
02
MW-4
«49
EXPLANATION
perched monitonng well showing
concentration in mg/L
temporary perched momtonng well
showing concentration in mg/L
perched piezometer showing
concentration in mg/L
temporary perched nitrate monitoring well
showing concentration in mg/L
perched momtonng well installed Apnl
2011 shovnng concentration in mg/L
perched chloroform extraction well
shovnng concentration in mg/L
HYDRO
GEO
CHEM, INC
NOTE MW-4. MW-26. TW4 4. TW4 19 and TW4-20 are pumping wells
LOCATIONS OF CROSS SECTIONS
AND KRIGED 3rd QUARTER, 2011 NITRATE (mg/L)
(NITRATE + NITRITE AS N)
APPROVED
SJS 05/01/2012
Hy718000/nitrate2011/
CAP/App/Vnit0911xsv2 srf Al
elevation (feet amsl)
lESB
25
^ CO
o ^
00 o
S o
» CO
3
CO
o 3 3 S.
000 ooco CO C 3-^3 :R OJ
O (O OA
09 05-
o S " -
3 (D
5= _
3 o
-Tl BT
00 V
3 £
n o K
5 g
n
^5
J». CD
l\5
m
m o
s w < x « m
m m O
>zg
mCO
Wo
c
9.
CO
03
O
CD
SL o
Z3
CQ
O —^
o
CO CO CO CD
o
6
Z3
CD*
CD
TWN-12 Ut
elevation (feet amsl)
CJi cn cn cn js^ 4i. Ji. cn cn -vi CO
OOOO
cn cn cn -vj -^^ >J -<. CO cn ooo
3 00 -n to
ii
<D
9 3
E3 • V
00 coo coo
3 3
o a-<Q
» S 3 3 o ^
300
u 0> §
00 CO c 3-
O (D
£* =
io
3 O
TI 5»
o CO
to
v >
p
3 S ~ 3 r- » R S 5. to <D
V >
$00
z H m
CO 5
«m
m s
ii
m H
Wo
m 0) H
>
CO
® i
0 3 8 o
= 01
3
CO
01
O
o
o
CQ
O
11
3 5
O JV3
S. o
elevation (feet amsl)
20)
9 c
= 03
•n e
= a-
w a
c tu
3 2.
tu CO 3 so
9 a-3 CO
35.
04
00 coo C IU o q 3 =3 o rico O^o 3
^ * 3 9 3 B.
CO CO
C 3-^ tt
O CP
05
Tl 9 §^Z 5 3 o O
tt tt g
v >
C3-0 O 5
(o 3
3 >
o 3
V >
3 3
CO ><
i='3
—, CD S >
o z o
^3
XI GO < o Oo
m
3}
Sa
w ^
m O
li
H X m > (fl
H
V Q.
CO #—•• 03 ZJ O CD
E. o
CQ
O
O CO CO
CO CD O
O 3
CD* CD
A. CO_M"
B tt IU 0)
3 T3 T3 .5
3-0 •D-D 2 O O o
9- >5 5 X Si3 3 3 55. & £ tt
<P CD o
c w —
° 2 o S" Q S 0 2
o CO rr <o
f I a 2. s <
5 o g S
^ S o o
« "5 » 3 o
252 »
APPENDIX B
LITHOLOGIC LOGS FOR
MW-3A, MW-30, MW-31, MW-34, AND MW-37
Uote ^-l^-^S. 6eologist_Liikldl£t!
Property «/''.a:/^?z,';(»/>!•//.. project
County .Tton stQ,g M|ah
Drilling Co A/i.(i„^j,t'}n
—Unit No
Hole No /VX/ 1/1
Twp Rge
)ofe • y-i^-gf Geolooist L ^s^.fc/^/A
ProDertv/i//>/^y»/JavW.// p^^jg^,
County Ju^ft siQte t/'^a/?
Drilling Co &>y/{tT/i>tf/,>r»;>»o g»
. Unit No Sec
Hole No Mu/-lo
Twp ?7.<
sus-P
625
65-0-C
723
SftO-
f
wo
f 3 1 Q I 1 1 i -J-i
SlU.sKjlt; 1 ' 1 r r
Vlfijif vrC P ll
•F f Si t}
»)l^vR-H{ v*. fi. • K1
-r-•*\ Si 14
f 51^ l) .Pra^S <;0p<'<i fvnilbU
-tlif^n-uHl .p. p sa
+^ sr fl T /f-fl)-!-* A m u ' t ^1 i''
(O SI-Si
lA M S'-tl
ifU. ts 1 W y .V
\ ,•
P •it
t rr -t, ri ' ESSisiflBasii»Cii£i
If HI k/U w-in i • i 1 i • M IS 1
ft *J lipftjr-RrH.tlMj ton's Mb*-a.ppf»i lf>'\.l->p-
A* i _ i % h i 1? •ti i
V
PERCEHTAQE COHPOSITION IMAGE
Dote . 4-5-05 Geologist L. rA^^L^ll
Property tA))>.b ^^f'^>,|/»«.tl project
CountySlQte JdtJi
Drilling Co h6i^U<: Ay|^rA^/)fl /:i.
. Unit No Sec .31.
Hole No M^-li
Twp 37$ Rge
Elev^LSi^
'^"i^ffn, Drilling Co £^d?/^ri7?f>/> Hole No .^il^t^ilSL
Property fet/A,/^^/>V.V>/^yi! Project __ un.f No Sec JJ1_ Twp 32^ Rge
• Slole -UfliK LoCQhon Elev - ri»/y County -TAA JaKrs
I il i
penCEHTAGE COUPOSmOH IMAGE
10 4 0AM,SIUVeF< ARROV^ STONE «S6 i 1 X 12
Dote
Pro ptfrly /aA>tiif
Coun ty xTyt^yu
Project 12,1 /i^j^'^SrJC
Slate -i^^^SA
Onlltng Co <3>
UfxH No Sec
Hole No
_ Twp Rge
Date .^STA/'e. ZP/f
Property H^hi.fz. \,V\.P.\-^ Vi\\\\
Coorxty '^Alft rL.tA/^
Geologist I ChZ6.lat>{\r
Project
Stote L/-t&.K
Drilling Co B.A.j)».t Cifplpy>at<oAjTing
Unit No Sec
Hole No MJ^'^'y
Tvifp Rge