DRC-2014-002761 - 0901a06880425a53

State of Utah
GARY R. HERBERT
Governor
SPENCER J. COX
Lieutenant Governor
Department of
Environmental Quality
Amanda Smith
Executive Director
DIVISION OF RADIATION CONTROL
Rusty Lundberg
Director
TO: File
M EMORANDUM DRC-2014-002761
THROUGH: Phil Goble, Compliance Section Manager
THROUGH: Russ Topham, P.E.
FROM: Tom Rushing, P.G. , lj<
DATE: April 8, 2014
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SUBJECT: Energy Fuels Resources (USA) Inc. December 23, 2013 Proposal for Remediation
of Nitrate Contaminated Soils Phase I of Final Nitrate Corrective Action Plan, May
7, 2012 and Stipulation and Consent Order of December 12, 2012, Docket No.
UGW12-04: DRC Findings
Summary:
Energy Fuels Resources (USA) Inc. ("EFR") submitted the White Mesa Uranium Mill, Proposal
for Remediation, Phase I of Final Nitrate Corrective Action Plan, May 7, 2012 and Stipulation
and Consent Order of December 12, 2012 Docket No. UGW12-04 ("Phase I Report"), dated
December 23, 2013 and received by the Utah Division of Radiation Control ("DRC") on
December 24, 2013. The Phase I Report is required by a December 12, 2012 Stipulation and
Consent Order which formally approved an EFR May 7, 2012 Corrective Action Plan ("CAP") to
remediate nitrate contamination in groundwater beneath the White Mesa Uranium Mill located in
San Juan County.
Per the CAP Phase I is required to include source control for soil contamination at the ammonium
sulfate crystal tanks as identified during onsite investigation and soil sampling activities at the
White Mesa Mill. The Phase I Report is required to comply with Utah Administrative Code
R317-6-6.15 and per the approved CAP language is required to include:
• Determination, to the satisfaction of the Executive Secretary, of the physical extent ofthe
soil contamination observed at the ammonium sulfate tanks near borings GP-25B Nitrate +
Nitrite (as N) 1,530 mg/kg-dry at depth of 6 feet) and GP-26B (Ammonia (as N) 1,590
mg/kg-dry at a depth of 16 feet) that were part of the nitrate investigation. Such effort shall
include an estimate of the volume (the "Contaminated Soil Volume") ofthe contaminated
195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144850 • Salt Lake City, UT 84114-4850
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EFR 12/23/2013 Phase I Nitrate CAP Proposal
DRC Review Memo
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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,
• Either a Plan and Schedule, 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
infiltration 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 in the Mill's tailings
impoundments,
• If EFR chooses to cover the Contaminated Surface Area with concrete, EFR must remove
the contaminated soil volume at a later date prior 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, Denison proposes to
construct a sloped and drained concrete pad of six inches in depth over an area covering
the lateral extent of contamination to be determined as discussed in Section 7.1. EFR 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 in the tailings area of twice the volume of contaminated soil
identified in the contamination investigation
Additionally, the CAP Part 7.1.1.1. states: "Denison anticipates that the presence of ammonia
contamination will diminish with distance from the ammonium sulfate tanks. The initial 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 initial sample row indicate that ammonia and
nitrate levels do not exceed DRC's proposed screening levels of 2 times the background levels
determined in the June 2011 investigation, specifically 4.29 mg/kg for ammonia and 4.38 mg/kg
for nitrate, no further samples will be analyzed and the pad will be constructed as shown in
Figure 11-2B. That is, if the initial samples are below the screening 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."
Director Approval of an Extension of Time for EFR to Submit the Phase I Surety Report:
The Director approved an extension of time for EFR to submit the Phase I Surety Report (based
on delineation of the nitrate contamination) by letter dated January 28, 2013 in order to allow EFR
to perform a second round of soil sampling which was not anticipated by the original consent
order and CAP. The extension of time granted an additional 60 days to submit the surety cost
estimate, on or before April 10, 2013. The second round of sample results were subsequently
received by EFR between March 11, 2013 and March 26, 2013 which indicated that the
contamination had not been delineated northeast ofthe proposed concrete pad and that ammonia
was not delineated due east and south of the Mill process building.
Therefore, per conference calls between EFR and DRC it was agreed that a third geoprobe soil
sampling event would be undertaken. As discussed below, the analytical results ofthe third
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sampling event still did not delineate the extent of the soil contamination. It was noted by EFR
during subsequent telephone conversations that the soil contamination may be more extensive
than anticipated, may be associated with fill material used for the ore storage pad, and that
according to EFR review the contamination from the ammonia crystal tanks could not be the
cause of areas of observed contamination. It was agreed between DRC and EFR that a Phase I
report and proposed concrete pad delineation would be submitted for Director review based on the
three rounds of soil sampling data.
Nitrate and Ammonia Soil Sampling and Laboratory Analysis (QA/QC)
Geoprobe Soil Core Sample Collection
Soil sampling was conducted by Earth Probe Environmental Field Services during three separate
sampling events as follows:
• Event 1 - January 3-5, 2013, 54 samples, 6 field duplicates and 3 rinsate samples were
submitted to American West Analytical Laboratories for analysis.
• Event 2 - February 26, 2013 - March 1, 2013, 93 samples, 10 field duplicate samples and
5 rinsate samples were submitted to American West Analytical Laboratories for analysis.
• Event 3 - June 6-8, 2013, 126 samples, 12 field duplicate samples and 2 rinsate samples
were submitted to American West Analytical Laboratories for analysis.
Samples were collected using a geoprobe continuous hollow stem with cutting foot. After boring
to refusal the core was placed on a table for examination and physical logging (stratigraphic
column). Samples were then collected from the top ofthe core (discounting fill material), the
middle of the core and at the bottom of the core. Samples were placed into Ziploc bags for
crushing (hand crushed) then put into sample bottles. Excess sample was kept in the Ziploc bag
and kept cool in case further evaluation was deemed necessary. Equipment was decontaminated
between each core location using the method outlined in the approved CAP. Equipment blanks
(rinsates of the cutting shoe) were collected every twenty samples as required by the CAP. DRC
staff performed a site inspection of the sample collection on January 3, 2013 and verified that the
protocols required by the CAP were being followed.
Photo - Geoprobe sampling at ammonia crystal tank area
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Sample bottles were labeled and cooled. Samples were driven to the EFR contract laboratory,
American West Analytical Laboratories (AWAL), for analysis.
Laboratory analytes and methods used by AWAL were as follows:
Ammonia (as N) mg/kg dry, Method E350.1
Ammonia (as N) mg/L aqueous extraction Method 1312, Analysis Method E350.1
Nitrate/Nitrite (as N) mg/kg dry, Method E353.2
Nitrate/Nitrite (as N) mg/L aqueous extraction Method 1312, Analysis Method E353.2
Percent Moisture %, Method SM2540B
Per DRC review of QA/QC performed by AWAL it was noted that some samples for ammonia
had analyte concentrations that were too high for accurate matrix spike recovery and/or RPD.
Several samples were filtered with a 0.7pm glass fiber filter after a 1:20 Dl water extract for soils.
Some sample analysis for Nitrate/Nitrite (as N) had high RPD due to suspected sample non-
homogeneity or matrix interference. None of the data was disqualified based on these QA/QC
flags.
It was noted that the third quarter equipment rinsate samples (five samples total) did not meet
temperature requirements when they arrived at the laboratory. EFR contacted DRC concerning
this issue when they were notified by the laboratory. DRC advised EFR that based on DRC
findings during the first sampling event geoprobe boring inspection it was not necessary to
recollect the soil samples. DRC also noted that none of the previous sampling events indicated
contamination to the geoprobe cutting shoe.
Per DRC review of the laboratory data results and QA/QC it appears that the data was analyzed
according to agreed upon methods and that the data results were adequately qualified.
DRC Inspection Findings During: the 1 Round of Soil Sample Collection
DRC accompanied EFR staff and consultants (Hydro Geo Chem and Earth Probe Environmental
Services) to conduct an inspection of the geoprobe work and soil sample collection during the first
sampling event. DRC specifically observed the following:
• Equipment - Geoprobe (see photo above), sample collection sleeves, drill stem and shoe,
field equipment,
• Documentation Procedures - Geological Logging (Stratigraphic Columns) and equipment
(e.g. color charts, plasticity methods etc.) including documentation of any issues which
occurred during the drilling, Laboratory Paperwork and Labeling,
• Decontamination Procedures - Field equipment and geoprobe shoe,
• Sample collection procedures - bagging, crushing and bottling of soil samples,
Per DRC observations no issues of concern were noted during the inspection.
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Ammonia and Nitrate Concentrations and Depth Profiling
Per the approved CAP, EFR was required to sample and bound nitrate and ammonia
concentrations in soil according to the calculation of Background + 2a: (as determined during the
nitrate source investigation activities). Specifically those concentrations were:
Ammonia - 4.29 mg/kg ammonia (as N)
Nitrate - 4.38 mg/kg nitrate (as N)
Sample results obtained indicated that nitrate concentrations in soil extended far beyond the
ammonium sulfate crystal tanks and per the Phase I Report it was determined that concentrations
beyond a certain point could not be attributed to the ammonium sulfate crystal tanks based on "a
relatively continuous portion of the identified nitrate and ammonia, east of and adjacent to the
Mill process building, can be geographically associated with the ammonium sulfate tanks. This
includes the area of the former damaged ammonium sulfate pad and areas immediately to the east
of that pad and along the eastern edge of the Mill process building. The contamination appears to
extend to bedrock at specific points in this area. The distribution of ammonia (with or without
nitrate) in the area of the former damaged ammonium sulfate pad, and areas immediately to the
east of that pad and along the eastern edge of the Mill process buildings is consistent with the
following conceptual model: spillage of ammonium sulfate crystals on the ground near the tanks,
dissolution of any spilled crystals not subsequently removed from the ground by any surface water
present, and downslope transport and infiltration of dissolved ammonia. Some nitrate would then
be expected to be generated in the subsurface through oxidation of dissolved ammonia.'''' The
Phase I Study goes on to discount other areas where soil samples indicate concentrations above
Background + 2a as follows: "the remainder of the area where nitrate and/or ammonia
contamination was detected extends northeast of the ammonium sulfate area to the ore storage
pad, and also appears to extend to bedrock at specific points in this area. However, constituents
detected in this area cannot be logically connected to the ammonium sulfate handling activities
and the distribution of these constituents is inconsistent with the above conceptual model."
The EFR argument is that any groundwater contamination resulting from ammonium sulfate
crystal would be evident primarily by ammonia concentrations in groundwater. Nitrate would be
secondary due to oxidation of the ammonia. The southwest to northeast cross section shows a
combination of contaminants plume (ammonia and nitrate) extending approximately to boring
P4A-05. As discussed below the current Phase I Pad is delineated to cover this area, however,
using this method is negating other areas with significant soil nitrate concentrations as depicted on
surface contour maps (shallow, middle and deep), e.g. 50 mg/kg in the shallow core sample
P7C-03. More discussion is provided regarding this finding in the section below.
EFR Study Findings and Phase I Concrete Pad Delineation
Attachment 4-1 of the Phase I Study is an aerial map depicting the area of the proposed concrete
cover and areas of existing asphalt which are proposed to be left in place. Per DRC review ofthe
Phase I Study and proposed area of concrete cover it was noted that several improvements
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regarding engineering specifications, engineering annual inspections, and additional area of
concrete cover (based on high soil concentrations of nitrate) need to be included. Additionally, it
was noted during DRC inspections of the existing concrete and asphalt that significant erosion,
cracking and spalling has occurred (photos below). Additionally, it has been noted during past
inspections that the storm drain located on the east side of the Mill building does not drain
correctly. It appears that drainage moves from south to north and that storm water and wash water
pools around the north portion of the drain system. Based on these findings the concrete drainage
needs to be replaced or repaired/reconstructed such that these drainage issues are corrected and
that other areas of existing concrete and asphalt need to be repaired/replaced as appropriate.
Photo 1 - Cracks in Existing Asphalt Southeast Area of Mill Building
i •
Photo 2 - Spalling and Cracked Concrete East of Mill Building
Attachment 4-1 ofthe Phase I Report depicts the proposed concrete cover and soil excavation
plan. Per the attachment it appears that EFR will provide grading such that drainage is interior in
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the area east of the mill process building, however EFR does not address how storm water
drainage into that area (bathtub depression) will be addressed to insure that surface ponding does
not occur within that area. Attachment 4-1 needs to include contours for the entire area, drainage
arrows, and inlet structures to clarify how runoff and process water will be diverted and managed
in this area. Additional discussion is included in the Engineering section of this memo below.
According to DRC review of the areas delineated for cover, based on soil sampling results, DRC
understands the EFR argument (conceptual model) that contamination associated with ammonium
sulfate crystal would result in concentrations of both ammonia and nitrate. However, DRC noted
that significantly higher nitrate concentrations were apparently found in nearer vicinities of the
ammonia crystal sulfate tanks than at areas farther away. These findings are depicted on Figures
3-1 A, 3-2A and 3-3A of the Phase I Report. Figure 3-1A {Shallow Nitrate Concentrations)
depicts nitrate concentrations with a concentration center at the ammonium sulfate crystal tanks
and decreasing with distance from that location.
Nitrate concentrations extend northeast from the ammonium sulfate crystal tanks toward the area
of the grizzly with relatively high concentrations extending as far northeast as P9C-01 (12.4 mg/L,
Lab Sample ID 1306183-031). This extent of the soil contamination is consistent with the middle
depth soil concentrations, higher nitrate concentrations at the ammonia sulfate crystal tanks
extending northeast to approximately boring P9C-01. DRC notes that these areas are located on a
sloped area which drains south towards the mill building. In order to provide corrective action to
prevent infiltration from these areas with higher than surrounding soil nitrate concentrations, DRC
recommends that the plotted area for concrete installation be extended north to include these areas
(concrete to extend north to soil boring P9C-01. This would cover essentially all areas with
nitrate soil concentrations greater than 10 mg/L.
Per discussion below, DRC also notes that grading and drainage directions relative to the
proposed concrete pad need to be included on the concrete cover plan, including additional areas
recommended for concrete cover. Additionally EFR needs to address drainage from areas
surrounding the concrete pad to insure that storm water does not pool in areas outside of the
concrete pad area, which would promote additional infiltration in those areas.
Engineering BAT Maintenance and Inspections
DRC Inspection of the Proposed Concrete Cover Schematic (Phase I Report Attachment 4-1) and
Drainage East of the Mill Building
Attachment 4-1 ofthe Phase I Report depicts the proposed concrete cover and soil excavation
plan. Per the attachment and discussion above it appears that EFR will provide grading such that
drainage is interior in the area east of the mill process building, however, the Phase I Report does
not clearly identify how storm water and process water drainage within this area will be managed
to provide efficient drainage and ensure that ponding does not occur. Additionally, as discussed
above, areas of existing concrete and asphalt with are planned to be kept are in disrepair and are
incorrectly graded for efficient drainage as discussed above.
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Attachment 4-1 needs to include the following items.
• Elevation contours for the concrete cover need to be included,
• Elevation contours for soil areas need to be included,
• Drainage direction arrows need to be included,
• Drainage inlets need to be included.
• Specifications for concrete seam sealing needs to be included with the attachment
• Specifications for curbing around the margin of the concrete needs to be included
• Explanation of repairs to be undertaken for concrete under the ammonia sulfate crystal
tanks needs to be included
DRC Review Comments Regarding Phase I Concrete Pad Construction and Drainage
Attachment 5 of the Phase I Report includes EFR redline changes to the White Mesa Mill
Discharge Monitoring Technology ("DMT") Plan for Concrete and Asphalt Inspection and
Maintenance (EFR Revision 12.2). Attachment 5 also includes changes to the DMT inspection
form for the annual decontamination /ammonium sulfate inspection to include the new concrete
cover area. These changes were made in order to address Part 7.1.3 ofthe CAP which states:
Per Part 7.1.3 ofthe CAP: "Denison 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
Minimization Technology ("DMT") Plan, to be submitted following approval of the CAP by the
Executive Secretary. The revised DMT Plan will address:
• frequency of inspection and photographic documentation of the condition of the pad
(annually),
• contents of inspection reports,
• inspection criteria,
• conditions requiring repairs,
• timing of repairs, and
• contents of repair reports"
DRC had the following findings and needed improvements were noted regarding the DMT Plan
Changes which were submitted with the Phase I Report:
• The frequency of the proposed DMT Plan changes is annual as included on the revised
DMT inspection form
• The content of the inspection reports has been amended to include verification that there
are no cracks on asphalt surface greater than 1/8 inch of separation, findings regarding any
deterioration or damage of the asphalt surface, and documentation of any repair work
• Per the updated DMT Monitoring Plan, all repairs needed per the inspection will be made
within seven calendar days of the detection and will be documented on the 2nd Quarter
DMT Monitoring Report which is due on September 1 of each calendar year.
Conclusions
Based on a conference call between DRC and EFR representatives on April 8, 2014 and
discussion ofthe above items regarding the Phase I Ammonium Sulfate Crystal Tank Concrete
Cover it was agreed that a revised construction plan will be submitted to DRC by May 22, 2014.
U:\MON_WAST\Trushing\Energy Fuels\Nitrate Corrective Action Plan\12-23-13 Phase I Report Ammonia Pad\EFR Phase I Nitrate Report DRC
Findings Memo.docx