HomeMy WebLinkAboutDRC-2021-008103 - 0901a06880eb3433June 7, 2021
ENERGY FUELS
Div of Waste Management
and Radiation Control
JUN 0 8 2021
Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
D RC —2021— 006 (0 3 www.energyfuels.com
Sent VIA OVERNIGHT DELIVERY
Mr. Doug Hansen
Director
Division of Waste Management and Radiation Control
Utah Department of Environmental Quality
195 North 1950 West
Salt Lake City, UT 84116
Re: Transmittal of Energy Fuels Resources (USA) Inc. ("EFRI") Errata Pages for the
Background Report for MW-38, MW-39, and MW-40, White Mesa Uranium Mill,
Blanding Utah
Dear Mr. Hansen:
On May 26, 2021 a teleconference between the Division of Waste Management and Radiation
Control ("DWMRC") DWMRC, EFRI, and EFRI's consultant, 1NTERA was held to discuss
DWMRC's review of the March 4, 2021 Background Groundwater Quality Report for
Monitoring Wells MW-38, MW-39, and MW-40. During their review, DWMRC identified
errors in calculation of Groundwater Compliance Limits ("GWCLs") for pH in MW-38, MW-39,
MW-40, and gross alpha in MW-40. DWMRC also raised concern about the proposed GWCL
for manganese in MW-39 based on recent observations and requested that the GWCL be
recalculated using the complete data set rather than removing outliers.
DWMRC requested errata pages correcting and adjusting the GWCLs in question. The pages
enclosed include changes as described below and are intended to replace the same pages in the
hard copies of the March 4, 2021 Background Groundwater Quality Report.
Electronic portable data format ("PDF") files of the errata pages and a revised electronic copy of
the complete Background Groundwater Quality Report are being provided via email.
Changes to the Background Groundwater Quality Report include:
• Text pages 5-6
- Section 3.2, modified text to include manganese in MW-39 as a significantly
increasing constituent, and
- Section 3.3, removed erroneous reference to Appendix G.
Letter to Doug Hansen
June 7, 2021
Page 2 of 2
Table 8
MW-38: Corrected pH GWCL calculation from mean plus 2 standard deviations
("SD") to mean minus 2 SD.
- MW-39: Corrected pH GWCL calculation from mean plus 2 SD to mean minus 2
SD., revised manganese calculations incorporating complete data set.
- MW-40: Corrected pH GWCL calculation from mean plus 2 SD to mean minus 2
SD., corrected calculation of gross alpha GWCL from Cohen's mean times 2
Cohen's standard deviations to Cohen's mean plus 2 Cohen's standard
deviations.
• Appendix C
- Page 11: Linear regression plot for manganese in MW-39 was revised using the
complete data set.
• Appendix F
- Outliers previously identified for manganese in MW-39 were removed from
Appendix F.
DWMRC acknowledged the limited data sets used to calculate GWCLs in MW-38, MW-39, and
MW-40, and proposed that EFRI review GWCLs considering all data available to date prior to
future Groundwater Discharge Permit ("GWDP") modifications. DWMRC will consider
adjustments to the GWCLs incorporated in future GWDP modifications using all available data
at the time of the next permit modification.
If you should have any questions regarding this report please contact me.
Yours very truly,
ENERGY FUELS RESOURCES (USA) INC.
Kathy Weinel
Quality Assurance Manager
CC: David Frydenlund
Logan Shumway
Scott Bakken
Terry Slade
2
3.0 RESULTS OF ANALYSIS AND DETERMINATION OF
GROUNDWATER COMPLIANCE LIMITS
MW-38, MW-39, and MW-40 are Class III wells based on their TDS concentrations (all three of
the wells have mean concentrations of TDS that are greater than 3,000 milligrams per liter
["mg/L"]) according to the rules set forth in UTAC R317-6-3.
3.1 Indicator Parameters
Chloride, sulfate, uranium, and fluoride have been identified as the best indicator parameters of
potential tailings cell seepage at the site, as described in Section 9.0 of the Existing Wells
Background Report (INTERA, 2007a). Review of the results for indicator parameters in each
well demonstrate that concentrations of indicator parameters in MW-38, MW-39, and MW-40
are not exhibiting significantly increasing trends (Appendix C, Table 8). Chloride, sulfate, and
uranium in MW-38 are not trending, and fluoride in MW-38 is decreasing slightly, though the
trend is not significant. Chloride, fluoride, and sulfate concentrations in MW-39 are stable to
decreasing slightly. Uranium in MW-39 is significantly decreasing. Chloride and uranium in
MW-40 are decreasing, and fluoride and sulfate in MW-40 are increasing slightly, but these
trends are not significant.
Evaluation of indicator parameters in MW-38, MW-39, and MW-40 supports the findings of
previous investigations at the Site, which conclude that there has been no impact to groundwater
from potential tailings cell seepage.
3.2 Trending Constituents
Trending constituents were identified by one of two trend test methods, according to the Flow
Sheet (Figure 2). Linear regression analysis was performed for normally or lognormally
distributed constituent data sets (Appendix C), and the Mann-Kendall trend test was performed
for the data sets which are not normally or lognormally distributed and contained 15% - 90%
NDs (Table 8). Statistically significant increasing trends include TDS in MW-38, potassium and
manganese in MW-39, and selenium in MW-40. Constituents that appear to exhibit increasing
trends that are not statistically significant include bicarbonate, and nitrate + nitrite, in MW-38;
gross alpha, and in MW-39; and fluoride and sulfate in MW-40. In addition to the constituents
listed here, and despite the generally decreasing trend in pH observed sitewide, pH in MW-38
and MW-40 is exhibiting an increasing trend. As described in Section 2.0, the strength of
statistical tests will increase with larger data sets, resulting in the potential for trending
concentrations in the future.
Background Groundwater Quality Report for MW-38, MW-39, and MW-40
White Mesa Uranium Mill Page 5 Blanding, Utah March 4, 2021 (revised June 4, 2021)
3.3 Groundwater Compliance Limits
GWCLs were determined based on the DWMRC-approved Flow Sheet (Figure 2) and in a
similar manner to the previous Background Reports. GWCLs for constituents in MW-38, MW-
39, and MW-40 that were not exhibiting any increasing trends were determined by following the
Flow Sheet without any modifications. Table 8 contains a summary of the results of the Flow
Sheet along with the proposed GWCLs based on that analysis. The GWCLs included in Table 8
include mean + two standard deviations (mean + 2 SD), Cohen's adjusted mean + 2 SD, highest
historical values (HHV), fractional, and Poisson Prediction Limits. The fractional approach
follows Utah Administrative Code ("UAC") R-317-6-4.6 B(2), Cohen's adjustment calculation
follows that outlined by the USEPA (2009) and the Poisson Prediction Limit is from USEPA
statistical guidance (1992).
3.4 Modified Approach for Groundwater Compliance Limits for Trending
Constituents
According to the DWMRC-approved Flow Sheet (Figure 2), if an increasing trend is present, a
modified approach should be considered for determining GWCLs for parameters listed in the
GWDP. Significant increasing trends in MW-38 (TDS) and MW-40 (selenium) can be attributed
to natural background conditions and are consistent with similar trends in other monitoring wells
at the Mill.
The UAC R317-6-4.6 recognizes that "contaminants" may be present as part of naturally
occurring background conditions:
When a contaminant is present in a detectable amount as a background
concentration, the concentration of the pollutant may not exceed the greater of
1.5 times the background concentration or 0.5 times the ground water quality
standard or background plus two standard deviations...
In this rule, background concentration is defined as the "concentration of a pollutant in ground
water upgradient or lateral hydraulically equivalent point from a facility, practice or activity
which has not been affected by that facility, practice or activity." Therefore, to be conservative,
the mean concentration was used for the purposes of this calculation. The mean concentration
assumes all data to date for calculation steps in the Flow Sheet.
UAC R317-6-4.6 also states that TDS may not exceed the greater of 1.25 times the background
concentration or background plus two SDs. For this reason, the modified-approach GWCL for
TDS in MW-38 was calculated by multiplying the mean by 1.25. The modified-approach GWCL
for selenium in MW-40 was calculated by multiplying the mean by 1.5.
Background Groundwater Quality Report for MW-38, MW-39, and MW-40
White Mesa Uranium Mill
Blanding, Utah
Page 6
March 4, 2021 (revised June 4, 2021)
TABLE 8
Summary of Flow Sheet GWCL Calculations Based on UDEQ-Approved Flow Sheet
Normally or
Lognormally
P4140#014R4
Linear Regression
Significant
Trend
Mann-Kendall Cohen Poisson Fractional
Significant Prediction Approach
Tmnd ..., Mean St. Dev. HHV Llrn1t,96% , (Class III)
Proposed Modified
Flowsheet Flowsheet GWCL Modified GWCL
GWCL Rationale GWCL Rationale
MW-38 Nutrients (mg/L)
MW-38 Ammonia 25 10 70% No 2 0.45567 0.0658 12 5 12.50 Fractional
MW-38 NitrateNitrite 10 10 0% Yes 0.59229 0 07121 0.3508 14.18 0.93190367 15.7 5 16.04 mean + 2SD
MW-38 Heavy Metals (pg/L)
MW-38 Arsenic 50 10 100% Not Tested 5.71 25 25 Fractional
MW-38 Beryllium 4 10 100% Not Tested 1.39 2 2 Fractional
MW-38 Cadmium 5 10 100% Not Tested 1.39 2.5 2 5 Fractional
MW-38 Chromium 100 10 100% Not Tested 19.47 50 50 Fractional
MW-38 Cobalt 730 10 100% Not Tested 9.47 365 365 Fractional
MW-38 Copper 1300 10 100% Not Tested 9.47 650 650 Fractional
MW-38 Iron 11000 10 100% Not Tested 22.62 5500 5500 Fractional
MW-38 Lead 15 10 100% Not Tested 2.04 7.5 / 5 Fractional
MW-38 Manganese 800 10 100% Not Tested 9.47 400 400 F actional
MW-38 Mercury 2 10 100% Not Tested 1.39 1 1.39 Poisson Prediction Limit
MW-38 Molybdenum 40 10 80% No 9 0.15018 13.3 20 20 Fractional
MW-38 Nickel 10 10 100% Not Tested 16.25 5 16.25 Poisson Prediction Limit
MW-38 Selenium 50 10 0% Yes -0.4462 0.19612 0.1991 163.2 7.77174369 175 25 178.74 mean + 2SD
MW-38 Silver 100 10 100% Not Tested 9.47 50 50 Fractional
MW-38 Thallium 2 10 100% Not Tested 1.39 1 1.39 Poisson Prediction Limit
MW-38 Tin 17000 10 100% Not Tested 63.76 8500 8500 Fractional
MW-38 Uranium 30 10 0% Yes -0.0386 0.91571 0.001 6.39 0.38464991 6.78 15 7.16 mean + 2SD
MW-38 Vanadium 60 10 100% Not Tested 12.94 30 30 Fractional
MW-38 Zinc 5000 10 80% No -15 0.03496 15.1 2500 2500 Fractional
MW-38 Radiologics (pCi/L) -
MW-38 GrossAlpha 15 9 67% No 8 0.18828 1.3 7 5 7.50 Fractional
MW-38 Vola Ile Organic Compounds (pg/L)
MW-38 Acetone 700 10 100% Not Tested 16.25 350 350 Fractional
MW-38 Benzene 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-38 Methyl ethyl ketone 4000 10 100% Not Tested 16.25 2000 2000 Fractional
MW-38 Carbon tetrachloride 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-38 Chloroform 70 10 100% Not Tested 2.04 35 35 Fractional
MW-38 Chloromethane 30 10 100% Not Tested 2.04 15 15 F actional
MW-38 Methylene chloride 5 10 100% Not Tested 2.04 2.5 2.5 F actional
MW-38 Naphthalene 100 10 100% Not Tested 2 04 50 50 Fractional
MW-38 Tetrahydrofuran 46 10 100% Not Tested 2.04 23 23 Fractional
MW-38 Toluene 1000 10 100% Not Tested 2.04 500 500 Fractional
MW-38 Xylenes, Total 10000 10 100% Not Tested 2.04 5000 5000 Fractional
MW-38 Other
MW-38 Chloride (mg/L) 10 0% Yes -0.1428 - 0.69391 0.0204 43.54 2.57992248 46.5 48.70 mean + 2SD
MW-38 Fluoride (mg/L) 4 10 0% Yes -0.5199 0.12345 0.2703 0.7027 0.1362653 1.03 2 0.98 mean + 2SD
MW-38 Field pH (s.u.) 10 0% Yes 0.62471 0.05349 0.3903 7.138 0.23006279 7.45 6.68 mean - 2SD
MW-38 Sulfate (mg/L) 10 0% Yes 0.09486 0.79436 0.009 2670 228.375908 3090 3126.75 mean + 2SD
MW-38 TDS (mg/L) 10 0% Yes 0.69321 0.02623 0.4805 Increasing 4007 147.048745 4240 4301.10 mean + 2SD 5008.75 1.25x mean
=INITERA Background Groundwater Quality Report for MW-38, MW-39. and MW-40 -
White Mesa Uranium Mill, Blanding, Utah
Page 1 of 3
TABLE 8
Summary of Flow Sheet GWCL Calculations Based on UDEQ-Approved Flow Sheet
LinaiL Normally or
Lognormally
Well Constituent GWQS N %ND Distributed?
giression Mann-Kendall Cohen Poisson Fractional Proposed Modified
Significant Significant Prediction Approach ., Flowsheet Flowsheet GWCL Modified GWCL
Trend S p Trend Mean St. Dev. HHV LinOt. .4., WRY, GWCL Rationale GWCL Rattapale
MW-39 Nutrients (mg/L)
MW-39 Ammonia 25 10 0% Yes -0.6114 0.06035 0.3738 0.2718 0.02923012 0.319 12.5 0.33 Imean + 2SD
MW-39 NitrateNitrite 10 9 33% No l - 3 0.00962 Decreasing 0.166 5 5 Fractional
MW-39 Heavy Metals (pg/L)
MW-39 lArsenic 50 10 100% Not Tested 5.71 25 25 Fractional
MW-39 Beryllium 4 10 0% Yes -0 7746 0 00852 0.6 Decreasing 4 987 0.48958145 5.94 2 5.97 mean + 2SD
MW-39 Cadmium 5 10 0% Yes 0 08191 0.82201 0.0067 2.718 0.14366628 2.97 2.5 3.01 mean + 2SD
MW-39 Chromium 100 10 100% Not Tested 19.47 50 50 Fractional
MW-39 Cobalt 730 10 0% Yes -0.2147 0.55146 0.0461 68 24 5.46487776 79.8 365 79.17 mean + 2SD
MW-39 Copper 1300 9 0% Yes -0.6573 0.05436 0.4321 29.733 2.90989691 35.4 650 35.55 mean + 2SD
MW-39 Iron 11000 9 0% Yes 0.00339 0.9931 1E-05 14700 403.112887 15300 5500 15506.23 mean + 2SD
MW-39 Lead 15 10 100% Not Tested 2 04 7.5 7 5 Fractional
MW-39 Manganese 800 10 0% Yes 0.72496 0.01768 0.5256 Increasing 2204 120.11106 2440 400 2444.22 mean + 2SD
MW-39 Mercury 2 10 100% Not Tested 1.39 1.39 Poisson Prediction Limit
MW-39 Molybdenum 40 10 100% Not Tested 20 Fractional
MW-39 Nickel 100 10 0% Yes -0.0184 0.95976 0.0003 33.59 39.25 mean + 2SD
MW-39 Selenium 50 10 100% Not Tested 5.71 25 25 Fractional
MW-39 Silver 100 10 100% Not Tested 9.47 50 50 Fractional
MW-39 Thallium 2 10 0% Yes 0.49431 0.14642 0.2443 3.444 0.18762847 3.83 1 3.82 mean + 2SD
MW-39 Tin 17000 10 100% Not Tested 63.76 8500 8500 Fractional
MW-39 Uranium 30 10 0% Yes -0.6393 0.04656 0.4087 Decreasing 12.02 0.96701143 14.2 15 13.95 mean + 2SD
MW-39 Vanadium 60 10 100% Not Tested 12.94 30 30 Fractional
MW-39 Zinc 5000 9 0% Yes -0.4667 0 20537 0.2178 243.89 7.55718937 257 2500 259.00 mean + 2SD
MW-39 Radiologics (pCi/L)
MW-39 GrossAlpha 15 9 0% Yes 0 52762 0.14432 0.2784 j 3.2189 1 12645955 5 11 J 7.5 5.47 mean + 2SD
MW-39 Volatile Organic Compounds (pg/L)
MW-39 Acetone 700 10 100% Not Tested 16.25 350 350 Fractional
MW-39 Benzene 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-39 Methyl ethyl ketone 4000 10 100% Not Tested 16.25 2000 2000 Fractional
MW-39 Carbon tetrachloride 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-39 Chloroform 70 10 100% Not Tested 2.04 35 35 Fractional
MW-39 Chloromethane 30 10 100% Not Tested 2.04 15 15 Fractional
MW-39 Methylene chloride 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-39 Naphthalene 100 10 100% Not Tested 2.04 50 50 Fractional
MW-39 Tetrahydrofuran 46 10 100% Not Tested 2.04 23 23 Fractional
MW-39 Toluene 1000 10 100% Not Tested 2.04 500 500 Fractional
MW-39 Xylenes, Total 10000 10 100% Not Tested 2.04 5000 5000 Fractional
MW-39 Other
MW-39 Chloride (mg/L) 10 0% Yes -0.2481 0.48948 0.0616 38.73 2.47568172 41.7 43.68 mean + 2SD
MW-39 Fluoride (mg/L) 4 9 0% Yes 0.02712 0.94479 0.0007 0.692 0.06310903 0.805 2 0.82 mean + 2SD
MW-39 Field pH (s.u.) 9 0% Yes 0.07202 0.85392 0.0052 4.17 0.16889346 4.53 3.83 mean - 2SD
MW-39 Sulfate (mg/L) 10 0% Yes -0.4015 0.25018 0.1612 3079 221.532541 3570 3522.07 mean + 2SD
MW-39 TDS (mg/L) 10 0% Yes -0.41 0.2393 0.1681 4216 248.739042 4560 4713.48 mean + 2SD
laMINNITERIX Background Groundwater Quality Report for MW-38, MW-39, and MW-40
White Mesa Uranium Mill, Blanding, Utah
Page 2 of 3
TABLE 8
Summary of Flow Sheet GWCL Calculations Based on UDEQ-Approved Flow Sheet
' „Regression
Significant
Trend
Mann-Kendall
Significant
p Trend Mean St. Dev. .,1141/,: ,
Poisson
Prediction
Limit 95%
Cohen Fractional
Approach Flowsheet
(Class III) " SD GWCL
Flowsheet GWCL
Rationale
Proposed
Modified
GWCL
Modified
GWCL
Rationale
MW-40 Nutrients (mg/L)
MW-40 Ammonia 25 10 80% No -5 0.30229 0.2 12.5 2.5 Fractional
MW-40 NitrateNitrite 10 10 0% Yes -0.8252 0.00329 0.6809 Decreasing 2.822 0.29483705 3.52 5 3.41 mean + 2SD
MW-40 Heavy Metals (pg/L)
MW-40 Arsenic 50 10 100% Not Tested 5.71 25 25 Fractional
MW-40 Beryllium 4 10 100% Not Tested 1.39 2 2 Fractional
MW-40 Cadmium 5 10 100% Not Tested 1.39 2.5 2.5 Fractional
MW-40 Chromium 100 10 100% Not Tested 19.47 50 50 Fractional
MW-40 Cobalt 730 10 100% Not Tested 9.47 365 365 Fractional
MW-40 Copper 1300 10 100% Not Tested 9.47 650 550 Fractional
MW-40 iron 11000 10 90% No 9 0.08187 41 5500 5500 Fractional
MW-40 Lead 15 10 100% Not Tested 2.04 7 5 7.5 Fractional
MW-40 Manganese 800 10 0% No -22 0.02966 206 400 400 Fractional
MW-40 Mercury 2 10 100% Not Tested 1.39 1 1.39 Poisson Prediction Limit
MW-40 Molybdenum 40 10 100% Not Tested 9.47 20 20 Fractional
MW-40 Nickel 100 10 100% Not Tested 16.25 50 50 Fractional
MW-40 Selenium 50 10 0% Yes 0.70593 0.02253 0.4983 Increasing 160.5 25.8639603 196 25 212.23 mean + 2SD 240.75 1.5 x mean
MW-40 Silver 100 10 100% Not Tested 9.47 50 50 Fractional
MW-40 Thallium 2 10 90% No -5 0.24312 0.603 1 1 Fractional
MW-40 Tin 17000 10 100% Not Tested 63.76 8500 8500 Fractional
MW-40 Uranium 30 10 0% Yes -0.3451 0.32869 0.1191 25.29 1.81625378 27.8 15 28.92 mean + 2SD
MW-40 Vanadium 60 10 100% Not Tested 12.94 30 30 Fractional
MW-40 Zinc 5000 10 80% No -17 0.01916 Decreasing 66.1 2500 2500.00 Fractional
MW-40 Radiologics (pCi/L)
MW-40 GrossAlpha 15 9 22% Yes -0.2394 0.53492 0.0573 1.3778 0.38005848 1.92 7.5 1.339 0.429 2.20 mean + 2SD (Cohen Adjustment)
MW-40 Volatile Organic Compounds (pg/L)
MW-40 Acetone 700 10 100% Not Tested 16.25 350 350 Fractional
MW-40 Benzene 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-40 Methyl ethyl ketone 4000 10 100% Not Tested 16.25 2000 2000 Fractional
MW-40 Carbon tetrachloride 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-40 Chloroform 70 10 100% Not Tested 2.04 35 35 Fractional
MW-40 Chloromethane 30 10 100% Not Tested 2.04 15 15 Fractional
MW-40 Methylene chloride 5 10 100% Not Tested 2.04 2.5 2.5 Fractional
MW-40 Naphthalene 100 10 100% Not Tested 2.04 50 50 Fractional
MW-40 Tetrahydrofuran 46 10 100% Not Tested 2.04 23 23 Fractional
MW-40 Toluene 1000 10 100% Not Tested 2.04 500 500 Fractional
MW-40 Xylenes, Total 10000 10 100% Not Tested 2.04 5000 5000 Fractional
MW-40 Other
MW-40 Chloride (mg/L) 9 0% Yes -0.5608 0.116 9 0.3146 41.433 3,88458492 47.1 49.20 mean + 2SD
MW-40 Fluoride (mg/L) 4 10 0% Yes 0.55728 0.09421 0.3106 0.6905 0.08394211 0 805 2 0.86 mean + 2SD
MW-40 Field pH (s.u.) 10 0% Yes 0.47601 0.16432 0.2266 6.762 0.24822928 7.06 6.27 mean - 2SD
MW-40 Sulfate (mg/L) 10 0% Yes 0.31499 0.37535 0.0992 2196 242.175327 2600 2680.35 mean + 2SD
MW-40 TDS (mg/L) 10 0% Yes -0.2445 0.49593 0.0598 3470 189.326291 3760 3848.65 mean + 2SD
Notes:
%ND = the percent of non-detected values in a data set.
pg/L = micrograms per liter.
GWCL = groundwater concentration limit.
GWQS = Ground Water Quality Standard (R317-6-2 UT Administrative Code).
HHV = Highest historical value.
mg/L = milligrams per liter.
N = number of data points in a data set.
p = probability, where a value <0.05 is significant.
M,INITERIX
pCi/L = picocuries per liter.
r = strength and direction of the linear relationship, where a negative value indicates decreasing trend.
r2 = The measure of how well the trendline fits the data where r2=1 represents a perfect fit.
S = Mann-Kendall statistic indicating how strong the trend is and which direction the data are trending (i.e. A large positive S value indicates
a strong increasing trend, where a small negative value indicates a weaker decreasing trend).
SD or Std. Dev. = standard deviation.
s.u. = standard units.
Background Groundwater Quality Report for MW-38, MW-39. and MW-40
White Mesa Uranium Mill, Blanding, Utah
Page 3 of 3
Ma
n
g
an
e
s
e
(
u
g
/1)
Ma
ng
ane
se
(
u
g
/1
)
Ma
ng
an
es
e
(
u
g
/1
)
Appendix C: Time Series Plots for All Constituents Showing Linear Regressions for
Normal and Log-Normal Distributions (Non-Detected Values are Substituted with the
Minimum Detection Limit)
Manganese in MW-38
14 —
12 —
10 —
8 —
6 —
2019 2020
Sample Date
Manganese in M -39
r 0.725 p = 0.0177 r = 0.5256
2400 —
2300 —
2200 —
2100 —
2000 —
2019 2020
Sample Date
Manganese in MW-40
200
180
160
140
120
100
2019 2020
Sample Date
Detect
Non-detect
— Regression tne
I TERA
Background Groundwater Quality Report for MW-38, MW-39, and MW-40
White Mesa Uranium Mill, Blanding, Utah
Page 11 of 38
Appendix F: Data That Have Been Removed or Modified Prior to Statistical Analyses
Field_Sample •cation_ .
-•
ate_
'm•144
Parameter_ ,.
Name
Report_
esult .... . ””
Report_U
nits , ........_ . lifi ,.,
mple_
Reason Removed .. , ,
MW-38_07182019 MW-38 7/18/2019 1Gross Alpha minus Rn and U 4.07 pCi/L GW Extreme Outlier
MW-39_07172019 MW-39 7/17/2019 Gross Alpha minus Rn and U 17.9 pCilL GW Extreme Outlier
MW-40_07162019 MW-40 7/16/2019 Gross Alpha minus Rn and U 5.24 pCi/L GW Extreme Outlier
MW-40_05032018 MW-40 5/3/2018 Chloride 53.9 mg/L GW Extreme Outlier
MW-39_05032018 MW-39 5/3/2018 Copper 51.1 ug/L GW Extreme Outlier
MW-39_10292019 MW-39 10/29/2019 Fluoride 1.11 mg/L GW Extreme Outlier
MW-39_05032018 MW-39 5/3/2018 Iron 12900 ug/L GW Extreme Outlier
MW-39_05032018 MW-39 5/3/2018 Nitrate + Nitrite as N 0.182 mg/L GW Extreme Outlier
MW-39_07102020 MW-39 7/10/2020 pH 5.08 pH Units GW Extreme Outlier
MW-38_11062019 MW-38 11/6/2019 Potassium 41 mg/L GW Extreme Outlier, non-regulated constituent
MW-39_05032018 MW-39 5/3/2018 Zinc 293 ug/L GW Extreme Outlier
Notes:
pg/L = micrograms per liter
mg/L = milligrams per liter
pCi/L = picocuries per liter
U = result not detected above the laboratory reporting limit
Background Groundwater Quality Report for MW-38, MW-39, and MW-40
White Mesa Uranium Mill, Blanding, Utah
Page 1 of 1