DRC-2021-006323 - 0901a06880e81be0

VI'Vk N.e•• 4ts„..419(,..:040
State of Utah
SPENCER J. COX
Governor
DEIDRE HENDERSON Lieutenant Governor
Department of
Environmental Quality
Kimberly D. Shelley
Executive Director
DIVISION OF WASTE MANAGEMENT
AND RADIATION CONTROL
Ty L. Howard
Director D - 20 21-00 323
MEMORANDUM
TO: Phil Goble Pg-6
FROM: Dean Henderson "2-6 -27
DATE: April 12, 2021
SUBJECT: Review of the February 22, 2021 4th Quarter, 2020 Chloroform Monitoring Report for
the Chloroform Contamination Investigation, Energy Fuels Resources (USA) Inc.
("EFRI") White Mesa Uranium Mill ("Mill"), near Blanding, Utah.
The Utah Division of Waste Management and Radiation Control ("Division") has reviewed the February
22, 2021 4th Quarter, 2020 Chloroform Monitoring Report ("Report") for the Chloroform
Contamination Investigation. For the review of this report the following regulatory enforcement
documents were used:
• EFR issued Ground Water Quality Discharge Permit No. UGW370004 ("Permit"). Permit
version that was signed on March 19, 2019.
• The EFR Quality Assurance Plan ("QAP") September 10, 2019 (Revision. 7.6)
• The EFR Groundwater Corrective Action Plan ("GCAP") September 14, 2015 (Revision 0)
• Utah Stipulation and Consent Order Docket Number UGW20-01, September 16, 2015.
REVIEW
GCAP Part III.0 requires the 4th Quarter Report to be submitted to the Division on or before March 1,
of each year. The Report was received by the Division on February 24, 2021 (date of Report
February 22, 2021) which meets the GCAP requirement.
Monitor Well Sampling
The following 42 monitor wells were sampled as required in the GCAP (see Table 1 below):
MW-4 TW4-3 TW4-8 TW4-13 TW4-21 TW4-26 TW4-31 TW4-36 TW4-41
MW-26 TW4-4 TW4-9 TW4-14 TW4-22 TW4-27 TW4-32 TW4-37 TW4-42
DRC-20 195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. I3ox 144880 • Salt Lake City, UT 84114-4880
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
Page 2
MW-32 TW4-5 TW4-10 TW4-16 TW4-23 TW4-28 TW4-33 TW4-38
TW4-1 TW4-6 TW4-11 TW4-18 TW4-24 TW4-29 TW4-34 TW4-39
TW4-2 TW4-7 TW4-12 TW4-19 TW4-25 TW4-30 TW4-35 TW4-40
The water samples for the above wells were analyzed for the following constituents as required in the
QAP:
Chloroform Chloride
Chloromethane Methylene chloride
Carbon tetrachloride Nitrate + Nitrite as Nitrogen.
The analytical methods used is consistent with the requirements of the GCAP. For a summary of the 4th
Quarter, 2020 and historic analytical results see Table 1 below.
Groundwater Head Monitoring
Depth to groundwater was measured in the following wells and/or piezometers, as required in Part I.E.3
of the Permit:
• The quarterly groundwater compliance monitoring wells.
• Existing monitoring well MW-4 and all of the temporary chloroform investigation wells.
• Piezometers P-1, P-2, P-3A, P-4 and P-5.
• MW-20 and MW-22.
• Nitrate monitoring wells.
• The DR piezometers which were installed during the Southwest Hydrologic Investigation.
In addition, weekly and monthly depth to groundwater measurements were taken in pumping wells
MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-21, TW4-22, TW4-24, TW4-25,
TW4-37, TW4-39, TW4-40, TW4-41, TW4-42, and TWN-2.
The monitoring wells were purged using the three approved QAP well purging strategies and meet QAP
requirements for each strategy:
1. Purging two casing volumes with stable field parameters for specific conductivity,
turbidity, pH, redox potential, and water temperature (within 10% RPD):
Wells: MW-32, TW4-5, TW4-8, TW4-9, TW4-16, TW4-18, TW4-23, TW4-32, and TW4-38.
2. Purging a well to dryness and stability of field parameters for pH, specific conductivity, and
water temperature only after recovery:
Wells: TW4-3, TW4-6, TW4-7, TW4-10, TW4-12, TW4-13, TW4-14, TW4-26, TW4-27,
TW4-28, TW4-29, TW4-30, TW4-31, TW4-33, TW4-34, TW4-35, TW4-36, and TW4-42.
3. The pumping wells are continuously pumped on a set schedule and are sufficiently purged to
collect a sample
Page 3
Pumping Wells: MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19,
TW4-21, TW4-22, TW4-24, TW4-25, TW4-37, TW4-39, TW4-40, and TW4-41.
Holding Times
The water samples method holding times for each parameter for samples collected at each monitor well
were received and analyzed within the required holding times stated in the QAP.
Receipt Temperature
Water samples were received within the required QAP temperature limit of 6° C.
Analytical Methods
The analytical methods reported to be use by the laboratory to analyze Chloroform, Chloride,
Chloromethane, Methylene chloride, Carbon tetrachloride, and Nitrate + Nitrite as Nitrogen are
incompliance with analytical methods required in the Chloroform QAP.
Detection Limits
Analyses were measured and reported to the required reporting limits. However, several sets of sample
results had the reporting limit raised for at least one analyte due to matrix interference and/or sample
dilution. In all cases the reported value for the analyte was higher than the increased detection limit.
EFR Duplicate Sample Comparison
Three duplicate samples were collected. Monitor well MW-32 and its duplicate sample TW4-65, and
TW4-8 and its duplicate sample TW4-70; and TW4-16 and its duplicate sample TW4-75. All analytical
results for the three sample/duplicate pairs were within the 20% relative percent difference (RPD)
acceptance limits (see Table 2 below).
Divisions Observations of EFR Sampling Procedures and Split Sample Duplicate Comparisons
On November 11, 2020 the Division staff observed the EFR staff sampling procedures and collected 8
split samples with EFR from wells TW4-7, TW4-8, TW4-9, TW4-16, TW4-18, TW4-29, TW4-30, and
TW4-33 To determine if sample results between two samples from two different laboratories are
comparable a relative percent difference ("RPD") of 30% or less is acceptable (DRC 2007 Guidance).
Out of the 56 parameters analyzed 5 parameters were exceeded 30% (see Table 3 below). Parameters
exceeding 30% are summarized in the table below:
Well and Parameter DWMRC EFR RPD
TW4-8 nitrate 0.16 1.27 155
TW4-16 nitrate 0.37 5.73 176
TW4-29 nitrate 0.75 3.27 125
TW4-30 nitrate <0.5 3.64 >30%
TW4-33 nitrate 0.12 3.71 187
Page 4
The likely cause of the nitrate concentrations exceeding the 30% RPD in the above five wells is the EFR
samples were analyzed with method E353.2 (28 day holding time) and the DWMRC samples were
analyzed with method E300.0 (48 hour holding time). Since the DWMRC samples exceed the holding
time the nitrate concentrations maybe inaccurate. Corrective action: 1) Assure the analytical laboratory
supplies sample containers for method E353.2 and containers and chain of custody are labeled
accordingly and, 2) resample monitor wells TW4,8, TW4-16, TW4-29, TW4-30, TW4-33 for nitrate in
the 2nd quarter 2021 monitoring event. Note, the EFR nitrate analytical results for these wells are typical
of historic concentrations (see Table 1 below).
Mass Removed and Plume Residual Mass
Chloroform removal was first estimated from the 1st Quarter, 2007. Since that estimation the mass
removed by each pumping well for each quarter has been calculated. Estimated reported mass removed
during the 4th Quarter 2020 is 9.6 lbs. (see Table 4 below) which is less than the estimated 13.4 lbs.
removed in the 3rd Quarter 2020. The smaller mass removal is a primarily due to decrease in
concentrations in TW4-19, TW4-37, and TW4-39.
Using the "Chloroform Plume Mass Calculation Method" as described in Appendix A of the GCAP the
residual mass of chloroform within the plume is estimated as 715 lbs. in the 4th Quarter, 2020. This
approximately 194 lbs. less than the 3rd Quarter 2020 estimated mass of 909 lbs.
As per Part III.B.2 of the GCAP, the electronic files were used in 4th Quarter, 2020 to calculate the mass
estimates. The following files were used to calculate the estimated chloroform mass within the
chloroform plume:
• Excel spreadsheet that included: well name; well location (easting and northing); Laboratory
reported concentration in p,g/1 in the 4th Quarter, 2020 and corresponding log equivalent values.
• Surfer® griding parameters: kriging parameters: SURFERTM default parameters (point kriging,
linear variogram, slope = 1, no anisotropy [anisotropy = 11, no search constraints; min x, max x
(UTME[m]): 631900, 633043; min y, max y (UTME[m]): 4154240, 4155550.64; grid spacing in
x, y (m): 15.24, 15.24
• Surfer chloroform concentration grid file.
• Concentration GE 70 Grid file
• Intermediate Surfer Grid Files: water level grid; aquifer base grid; saturated thickness grid
Based on the review of these files it appears that the date entered and generated is appropriate to
calculate an estimated chloroform mass within the chloroform plume and EFR followed Part III.B.2 and
Appendix A of the GCAP.
Reporting
The Report included the following information as required in the QAP:
a) Introduction
b) Sampling and Monitoring Plan
-Description of monitor wells
Page 5
-Description of sampling methodology, equipment and decontamination procedures
-Identify all quality assurance samples, e.g. trip blanks, equipment blanks,
duplicate samples
c) Data Interpretation
-Interpretation of groundwater levels, gradients, and flow directions.
Interpretations will include a discussion on: 1) A current site groundwater
contour map, 2) hydrographs to show groundwater elevation in each
monitor well over time, 3) depth to groundwater measured and
groundwater elevation from each monitor well summarized in a data table,
that includes historic groundwater level data for each well, and 4) an
evaluation of the effectiveness of hydraulic capture of all contaminants of
concern.
-Interpretation of all analytical results for each well, including a discussion
On: 1) a current chloroform isoconcentration map with one of the
Isoconcentration lines showing the 70 41, boundary, 2) graphs showing
Chloroform concentration trends in each well through time and, 3)
Analytical results for each well summarized in a data table that includes
Historic analytical results for each well.
-Calculate chloroform mass removed by pumping wells. Calculations
would include: 1) total historic chloroform mass removed, 2) total historic
chloroform mass removed for each pumping well, 3) total chloroform
mass removed for the quarter and, 4) total chloroform mass removed from
each pumping well for the quarter, 5) estimated residual mass of chloroform within the
plume.
d) Conclusions and Recommendations
e) Electronic copy of all laboratory results for Chloroform Investigation monitoring conducted
during the quarter.
0 Copies of DUSA field records, laboratory reports and chain of custody forms.
Evaluation of the Chloroform Contaminate Plume and Its Associated Contaminants
Bounding Chloroform Plume
Groundwater monitoring data up to the 4th Quarter, 2020 monitoring event appeared to show that the
chloroform contaminate plume ("Plume") and associated contaminants (carbon tetrachloride,
chloromethane, and methylene chloride) is bound by up gradient, cross gradient, and down gradient
compliance monitoring wells that have a chloroform concentration of <70 gg/L ("GWQS = 70 µg/L)
with the exception of TW4-24 (72.6 µg/L) and TW4-30 (82.8 µg/L).‘ If one or both of these two wells
exceed the 70 µg/L chloroform concentration in the 1st quarter 2021 chloroform monitoring event EFR
well be required to follow GCAP Part II.H.
Performance Monitor Wells ("PM") [Wells Exceeding Chloroform Concentrations GWQS of 70µg/L1
Six (7) PM wells still exceed 70 µg/L: TW4-7, TW4-10, TW4-16, TW4-26, TW4-29, TW4-30, and
TW4-33.
Page 6
Compliance Monitor Wells ("CM")_[Wells with Chloroform Concentrations between < 1 and 701,tg/L1
Eight (7) CM wells range with detectable chloroform concentration but still below 70µg/L: TW4-5,
TW4-6, TW4-8, TW4-9, TW4-14, TW4-18, and TW4-27.
CM Wells Below the Laboratory Chloroform Detection Limit (<1.0 pg/L)
Thirteen 13 CM wells were below the laboratory detection limit for chloroform (<1.0 pg/L): MW-32,
TW4-3, TW4-12, TW4-13, TW4-23, TW4-28, TW4-31, TW4-32, TW4-34, TW4-35, TW4-36, TW4-
38, and TW4-42.
Pumping Wells
There are 15 pumping wells in full operation in the 4th Quarter, 2020, 14 pumping wells MW-4, MW-
26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-21 TW4-22, TW4-24, TW4-37, TW4-39, TW4-
40, and TW4-41 exceed chloroform concentrations of 70 µg/L. Pumping well TW4-25 had a non-
detectable (<1.0 [tg/L) chloroform concentration (see table 1 below).
Nitrate, Nitrate + Nitrite ("nitrate") Concentrations
Pumping wells TW4-22 (64.9 mg/L) and TW4-24 (35.9 mg/L) exceed the nitrate GWQS of 10 mg/L.
These nitrate exceedances appear to be a result of the nitrate contaminant plume up-gradient of the
chloroform contaminant plume. This nitrate contaminant plume is being addressed under the Nitrate
Corrective Action Plan ("NCAP"), approved on December 12, 2012.
Well TW4-26 (11.9 mg/1) continue to exceed the nitrate GWQS of 10 mg/l. The source of nitrate may
be from the chloroform source plume. Pumping well TW4-40 located approximately 200 feet down
gradient of TW4-26 and should remove and prevented further elevated nitrate concentrations migrating
downgradient in this vicinity. Therefore, at this time no action is recommended. However, should future
nitrate concentrations in TW4-40 increases to above 10 mg/1 an additional investigation may be
recommended.
Well TW4-27 (16.7 mg/L) continue to exceed the nitrate GWQS of 10 mgn. The source of nitrate may
be from the chloroform source plume. Wells TW4-29, TW4-30, and TW4-31 located approximately
200 feet down and/or cross gradient of TW4-27 have nitrate concentrations in the 4th quarter 2020
below the GWQS of 3.27 mg/L, 3.64 mg/L, and 0.501 mg/L respectively. Therefore, at this time no
action is recommended. However, should future nitrate concentrations in these three down and/or cross
gradient wells increases to above 10 mg/L or shows an increasing trend an additional investigation may
be recommended.
Conclusions on Compliance with the Permit and QAP
Per the Division review it appears that the Report complies with Permit, QAP, and GCAP. Therefore, a
letter will be drafted notifying EFR of the review and closing out of for the 4th Quarter, 2020
Chloroform Monitoring Report for the chloroform contamination investigation.
Page 7
References
EFR Quality Assurance Plan ("QAP") June 23, 2018 (Revision. 7.4)
EFR issued Ground Water Quality Discharge Permit No. UGW370004. Permit version that was
signed on March 19, 2019.
EFR, White Mesa Uranium Mill, Notice of Violation and Corrective Action Order UDEQ
Docket No. UGW-20-01 Notice Pursuant to the Chloroform Pumping well Operations and
Maintenance plan, Letter August 5, 2020. (DRC-2020-013810)
EFR, White Mesa Uranium Mill Chloroform Monitoring Report 3rd (July through September)
Quarter 2020, November 16, 2020. (DRC-2020-018798)
EFR, White Mesa Uranium Mill Chloroform Monitoring Report 4th (October through
December) Quarter 2020, February 22. 2021 (DRC-2021-002766)
EFR, State of Utah Stipulated and Consent Order ("SCO") Docket Number UGW-20-01 White
Mesa Mill — Energy Fuels Resources (USA) Inc. ("EFRI") Plan and Time Schedule, Revision 1,
Pursuant to Part II.H.2 of the Groundwater Corrective Action Plan ("GCAP") included as
Attachment 1 to the SCO, January 10, 2018.
Utah Department of Environmental Quality Division of Waste Management and Radiation
Control, White Mesa Uranium Mill - Notice of Violation and Corrective Action Order UDEQ
Docket No. UGW-20-01 Notice Pursuant to the Chloroform Pumping Well Operations and
Maintenance Plan. Chloroform Contamination Investigation. Abandonment and Hydrogeologic
Investigation for Pumping Well TW4-20. Confirmatory Action Letter. September 28, 2020.
(DRC-2020-018798)
Page 8
Tables 1 through 4
TABLE 1 (1 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination investigation
DUSA White Mesa Min
MW-4 (chloroform puropmg well started pumping 3/ 4/03)
Sampling Event
Parameter
(GWQS) Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pgrL)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA 2,900 NA NA NA 6.3
2nd Qtr 5/25/2005 NA 3,170 NA NA NA 7.1
3rd Qtr 8/31/2005 <10 3,500 <10 <10 islA 7.0
41h Qtr 12/7/2005 <50 moo <50 <50 53 7.0
1st Qtr 3/9/2006 <50 3,100 <50 <50 49 ' --6:0
2nd Qtr 6/14/2006 <50 3,000 , <50 <50 49 . 6 0
3rd Qtr 7/20/2006 <50 2,820 <50 <50 48 1.2
4th Qtr 11/8/2006 2.1 2r830 1.4 <1.0 50 6.4
1st Qtr 2/28/2007 1.6 2,300 <1 0 <1.0 47 6.3
2nd Qtr 6/27/2007 1.8 2,000 <1.0 <1.0 45 7.0
3rd Qtr 8/15/2007 1.9 2,600 <1.0 <1.0 47 6.2
4th Qtr 10/10/2007 1.7 2,300 <1.o <1.0 45 6.2
1st Qtr 3/28/2008 1.7 2,400 <1.0 <1.0 42 5.6
2nd Qtr 6/25/2008 1.8 2,500 <1.0 <1.0 42 6.1
3rd Qtr 9/10/2008 1,8 1,800 <1.0 <1.0 35 6.4
4,g!....,21!"_. .:I.PM(399,8. 1.7 , 2„100 <1.0 <1.0 45 5.9
1st Qtr 3/4/2009 , 1.5 2,200 <1.0 <1.0 37 5.7
2nd Qtr 6/23/2009 1.3 1,800 <1,0 <1,0 34 5.2
3rd Qtr 9/14/2009 1.4 2,000 <1.0 <1.0 43 5.3
4th Qtr 12/14/2009 1.6 1,800 <1.0 <1.0 44 5.8
1st Qtr 2/17/2010 1.2 1,600 <1.0 <1.0 45 4.0 2nd Qtr 6/14/2010 1.2 2,100 <1.0 <1.0 41 5.1
3rd Qtr 8/6/2010 1.5 1,900 <1.0 <1.0 38 4.8
4g1..Q.t.r_... ...19/15/2010. 1.4 1 500 <1 0 <1.0 41 4.9
isi.Qir iiiiiioil 1.5 1,700 <1.0 <1.0 40 4.6
2nd Qtr 6/1/2011 1.4 1,700 , <1.0 <1.0 35 4.9
3rd Qtr 8/17/2011 1.1 1,700 <1.0 <1.0 41 4.9
4th Qtr 11/16/2011 1.3 ._1600 <1.0 <1.0 40 5.1 151 Qtr (1) 1/23/2012 1 1,500 <1.0 <1.0 41.0 4.8
2nd Qtr 6/6/2012 1.I , 1,400 <1.0 <1.0 39.0 4.9
3rd Qtr 9/4/2012 1.5 1,500 <1.0 <1.6 41.0 ,5,0
4th Qtr 10/4/2012 1 1.,300 <1.0 <1.0 41.0 4.8
let Qtr 2/11/2013 1.48 1,670 <1.0 <1.0 37.8 .08
2nd Qtr 6/5/201 S 1.31 1,490 <1.0 <1.0 44.0 4.22
3rd Qtr 9/3/2013 1.13 1,520 <1.0 <1.0 41.4 4.89
41h Qtr 10/29/2013 5.58 _1410 <1.0 <1.0 40.1 ....5.:.5. 1st Qtr 1/27/2014 4.15 , 1,390 <1.0 <1.0 38.5 4.
2nd Qtr 5/19/2014 5.21 1,390 <1.0 , <1,0 39.9 4.08
3rd Qtr 8/11/2014 , 7.6 1,490 <1.0 <1.0 41.0 3.7
41h Qtr 10/21/2014 1.0 1,440 <1.0 <1.0 41.5 5.07
1st Qtr (2) 3/9/2015 1.26 1,400 <1.0 <1.0 40.7 5.75
2nd Qtr 6/8/2015 <1.0 1,300 <1.0 <1.0 43.1 _2,53
3rd Qtr 8/31/2015 <1.0 1,200 1.42 <1.0 44.3 4.79
4th Qtr 10/19/2015 <1.0 .1200 <1.0 <1.0 40.8 4.43
1st Qtr 3/9/2016 <1.0 1,240 <1.0 <1.0 42.2 5.15
2nd Qtr 5/23/2016 1.44 1,580 <1.0 <1.0 43.7 4.54
3rd Qtr 7/25/2016 <1.0 1,430 <1.0 <1.0 42.5 4.95
4th Qtr 10/12/2016 1.24 .1470 <1.0 <1.0 44.8 4.88
1st Qtr 3/8/2017 . 1.22 1,450 <1.0 <1.0 43.3 4.99
2nd Qtr 6/13/2017 1.15 1,430 <1.0 <1.0 44.0 4.88
3rd Qtr 7/26/2017 1.15 1,400 <1.0 <1.0 43.8 4.59
4th Qtr 10/11/2017 <1.0 1,320 <1.0 <1.0 43.8 5,25
DWMRC wit sample <19 1.,40.0 <30 70 J 43.0 5,1
1st Qtr 3/12/2018 1.07 1,320 <1.0 <1.0 46.2 4.47
2nd Qtr 6/8/2018 <1.0 1,240 <1.0 <1.0 43.5 4.64
3rd Qtr 8/22/2018 <1.0 1,300 <1.0 , <1.0 48.5 4.55
4th Qtr 11/28/2018 <1.0 1.,310 <1.0 <1.0 43.1 4.44
1st Qtr 3/8/2019 <1.0 1190 <1.0 <1.0 41.5 5.05
2nd Qtr 6/5/2019 <1.0 , 1, 300 <1.0 , <1.0 40.6 5.16
3rd Qtr 9/4/2019 <1.0 1,180 <1.0 <1.0 41.9 4.69 4th Qtr 12/10/2019 <1 0 1 370 <1 0 <1 0 45 5 4 34
1st Qtr 2/19/2020 <1.0 1,230 <1.0 <1.0 48.1 6.22
2nd Qtr 5/27/2020 <1.0 1,250 <1.0 <1.0 , , 40.7 5.04
3rd Qtr 9/4/2020 <1.0 1,240 <1.0 <1.0 43.8 4.93
4th Qtr 10/18/2020 <1.0 1,050 <1.0 <1.0 41.4 4.62 MW-4A(TW4-A)
1st Qtr 3/16/2005 NA 3,700 NA NA NA 7.1
2nd Qtr 5/25/2005 NA 3,740 NA NA NA 7.8
3rd Qtr 8/31/2005 <10 3,800 <10 <10 NA 6.9
4th Qtr 12/7/2005 <50 3,000 <50 <50 55 6.7
1st Qtr 3/9/2006 <50 3,700 <50 <50 53 5.8
2nd Qtr 6/14(2006 <50 3,300 <50 <50 54 7.3
3rd Qtr 7/20/2006 <50 3,190 <50 <50 54 1.2
4th Qtr 11/8/2006 2.4 3,370 <1.0 <1.0 54 7.1
1st Qtr 2/28/2007 1.9 2,500 <1.0 <1.0 60 7.1
Well abandonded
(1) As of March 2012 both north and south wrld ponds no longer receiving water
(2) chloroforrn pumping wells TW4-1, T1N4-2, and TW4-11 started in 1/14/15
NA = not analyzer!
Shaded indicates concentrations exceeding GWQS.
Bold and italics indicates the MDL exceeded the GWOS.
J = Approximated value
TABLE 1 (2 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
MW-26 (former TW4-15) Chloroform pumping well started 8/8/03
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate . Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA 310 NA NA NA 9..3 . 2nd Qtr 5/25/2005 NA 442 NA NA NA 0.2
3rd Qtr 8/31/2005 <5.0 960 5.4 <5.0 NA 0.2
4t5 Qtr 12/7/2005 <50 1,000 <50 <50 55 6.
lst Qtr 3/9/2006 . <50 1,100 <50 <50 „ 52 0.2
2nd Qtr 6/14/2006 <50 830 <50 <50 52 0.2 , 3rd Qtr 7/20/2006 <50 2,170 <50 ;C50 65 '1 .4
4th Qtr 11/8/2006 <1.0 282 <1.0 2.6 54 0.3
1st Qtr 2/28/2007 <1.0 570 <1.0 5.5 56 0.6
2nd Qtr 6/27/2007 <1.0 300 <1.0 13 , 49 .4 0.„ 3rd Qtr 8/15/2007 <1.0 1,400 <1.0 36 57 1
4th Qtr 10/10/2007 <1.0 1000 <1.0 14 57 p.,§
1st Qtr 3/28/2008 <1.0 930 <1.0 40 49 0.1
2nd Qtr 6/25/2008 <1.0 1,300 <1.0 53 57 0.6
3rd Qtr 9/10/2008 01.0 630 <1.0 24 44 0.2
4th Qtr 10/15/2008 NA NA NA NA 64 0.1
11/18/2008 <2.0 lzpo <2.0 100 NA NA
1st Qtr 3/4/2009 <1.0 950 <1.0 51 49 0.4
2nd Qtr 6/23/2009 <1.0 410 <1.0 12 48 0.2
3rd Qtr 9/14/2009 <1..0 850 <1.0 30 46 0.1
4th Qtr 12/14/2009 <1.0 1100 <1.0 40 60 2.3
1st Qtr 2/17/2010 <1.0 7.8.0 <1.0 19 57 0.2
2nd Qtr 6/14/2010 1.2 1,600 <1.0 <1.0 40 6.8
3rd Qtr, 8/16/2010 <1.0 2,200 <1.0 21 49 0.6
41h Qtr 10/15/2010 <1.0 970 <1.0 6 5 65 0.7
1st Qtr 2/23/2011 <1.0 450 <1.0 3 6 . 57 , 0.5
2nd Qtr 5/31/2011 <1.0 1,800 <1.0 1.3 . „68 0.4
3rd Qtr 8/17/2011 <1.0 720 <1.0 7.2 58 0.9
4th Qtr 11/16/2011 NA NA NA NA 69 2.0
. . .1.). 12J5/2011 <1.0 1,800 <1.0 2.9 NA NA
16 1st Qtr.(2) 2/27/2012 <1.0 2,400 <1.0 98 1.7
2nd Qtr 6/6/2012 <1.0 , 3,000 <1.0 21 73 2.5
3rd Qtr 9/4/2012 <1 3,100 <1 , 31 73 2.6 4th Qtr 10/4/2012 <1 ..1200 <i 4 68 1.8
1st Qtr 2/11/2013 <1 2,120 <1 9.34 81.9 2.27
2nd Qtr 6/5/2013 <1.0 4,030 <1.0 52.4 779 2.11
3rd Qtr 9/3/2013 <1.0 2,940 <1.0 33.2 60.8 1.18
401 Qtr 10/29/2013 <1.0 1,410 <1 4.03
1st Qtr 1/27/2014 <1.0 1400 <1.0 13.8 59.4 . .. 0.55
2nd Qtr 5/19/2014 <1.0 1,960 <1.0 15.4 53.4 0.93
3rd Qtr 6/11/2014 <1.0 2,120 8.7 26 59 0.7
4t8 Qtr 10/21/2014 <1.0 2090, <1.0 23.2 60.1 ...9.:3, 1st Qtr 3/9/2015 <1.0 1,980 <1.0 27.4 56.5 0.73 2nd Qtr (3) 6/8/2015 <1.0 1,980 <1.0 11.2 62 0.42
3rd Qtr 8/31/2015 <1.0 2,350 4.05 11.6 69.6 0.68
4th Qtr 10/18/2015 <1.0 2680 1 32 8.28 62 6 0.991
1st Qtr 3/9/2016 <1.0 2,650 <1.0 4.66 68.3 1.45
2nd Qtr 5/23/2016 <1.0 2,220 <1.0 4.57 66.2 1.12
3rd Qtr 7/25/2016 <1.0 3,190 <1.0 7.81 66.4 1.57 416 Qtr (4) 10/12/2016 <1.0 2,510 <1.0 4.31 66.2 1.18
1st Qtr 3/8/2017 <1.0 1,290 <1.0 7.65 58.4 0.768
2nd Qtr 6/13/2017 <1.0 2,450 <1.0 7.59 64.3 0.922
3rd Qtr 7/26/2017 <1.0 1,230 <1.0 5.26 61.4 1.56
4th Qtr 10/11/2017 <1.0 2,570 <1.0 7.83 62.2 ............. ...1:18 , lst Qtr 3/12/2018 <1.0 1,210 <1.0 2.14 60.3 1.57
2nd Qtr 6/8/2018 <1.0 1,870 <1.0 9.19 58.7 0.901
3rd Qtr 8/22/2018 <1.0 1,680 <1.0 <1.0 91.4 2.80
41h Qtr 11/28/2018 <1.0 1,480 <1.0 <1.0 85.5 ............. 1.96
1st Qtr 3/8/2019 <1.0 1,110 <1.0 2.2 69.9 1.85
2nd Qtr 6/5/2019 <1.0 1,280 <1.0 1.19 80.7 2.53
3rd Qtr 9/4/2019 <1.0 1,680 <1.0 1.93 76.2 3.08
4th Qtr 12/10/2019 <1.0 1,390 <1.0 1.78 83.2 0.977
1st Qtr 2/19/2020 <1.0 1,100 <1.0 <1.0 88.9 1.17
2nd Qtr 6/12/2020 <1.0 1,140 <1.0 <1.0 35.1 2.93
3rd Qtr 9/4/2020 <1.0 1,130 <1.0 2.57 70 0.42
416 Qtr 10/28/2020 <1.0 866 <1.0 <1.0 37.4 _____ ,_ 3,62
(1) VOCs were resampled because laboratory missed holding time.
02)A3 of March 2012 WM north and south todld hie ponds no lonler receiving...water. 2) chloroform purnping_weirrw4-37 started in 6/9/15 2) chloroform pumpinteells 10V4-1 7W4-2 and TW4-11 started in 1/14/15
NA ix not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS.
TABLE 1 (3 of 31) Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
MW-32 (forrner 7W4-17)
Sampling Event
Parameter
(GWQS) Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA <1.0 NA , NA NA <0.1 2nd Qtr 5/25/2005 NA <1.0 NA, , , N,,! NA <0.1
3rd Qtr 8/31/2005 <1.0 <1.0 3.2 <1.0 NA <0.1 4th Qtr 12/7/2005 <1.0 <1.0 <1.0 <1.0 33 <0.1
1st Qtr 3/9/2006 <1.0 <1.0 <1.0 <1.0 32 <0.1, 2nd Qtr 6/14/2006 <1.0 <1.0 3.5 <1.0 30 <0.1
3rd Qtr 7/20/2006 <1.0 <1.0 , 1.8 <1,0 32 <1.0
41h Qtr 11/8/2006 <1.0 <1.0 1.5 <1.0 31 <,1
1st Qtr 2/28/2007 <1.0 <1.0 <1.0 <1.0 32 <1.0
2nd Qtr 6/27/2007 <1.0 <1.0 <1.0 <1.0 32 <1.0
3rd Qtr 8/15/2007 <1.0 <1.0 <1.0 <1.0 31 <1.0
41h Qtr 10/10/2007 <1.0 <1.0 <1.0 <1.0 32 <1.0 1st Qtr 3/28/2008 <1.0 <1.0 <1.0 <1.0 31 <.1
2nd Qtr 6/25/2008 <1.0 <1.0 <1.0 <1.0 29 <1.0 3rd Qtr 9/10/2008 <1.0 <1.0 <1.0 <1.0 30 <1.0
41h Qtr 10/15/2008 <1.0 <1.0 <1.0 <1.0 26 <0.05 1 st Qtr 3/4/2009 <1.0 <1.0 <1.0 <1.0 30 <.1
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 31 <0.1 3rd Qtr 9/14/2009 <1.0 <1.0 <1.0 <1.0 33 <0.1
4th Qtr 12/16/2009 <1,0 <1.0 <1.0 <1.0 35 <0.1
1st Qtr 2/17/2010 1,0 <1.0 <1.0 <1.0 38 <0.1
2nd Qtr 6/14/2010 <1.0 <1.0 <1.0 <1.0 32 <0.1
3rd Qtr 8/16/2010 <1.0 <1.0 <1.0 <1.0 28 <0.1
4th Qtr 10/15/2010 <1.0 <1.0 <1.0 <1.0 24 <0.1
1st Qtr 2/23/2011 <1.0 <1.0 <1.0 <1.0 40 <0,1 2nd Qtr 5/25/2011 <1.0 <1.0 <1.0 <1.0 31 <0.1
3rd Qtr 8/18/2011 <1.0 <1.0 <1.0 <1.0 33 <0.1
lth Qtr 11/16/2011 NA NA NA NA 32 <0.1
11).... 12/7/2011 <1.0 <1.0 <1.0 <1.0 NA NA Tif tifr (2) 1/18/2012 <1.0 <1.0 <1.0 <1.0 21 <0.1
2nd Qtr 6/22/2012 <1.0, <1 0 „„.. <1.0 <1.0 , 32 <0.1
3rd Qtr 9/5/2012 <1.0 <1.0 <1.0 <1.0 33 <0.1 4th Qtr 10/10/2012 <1.0 <1.0 <1.0 <1.0 35 <0.1
1st Qtr 2/11/2013 <1.0 <1.0 <1.0 <1.0 34.3 <0.1
2nd Qtr 6/18/2013 <1.0 <1.0 <1.0 <1.0 34.9 <0.1 3rd Qtr 9/3/2013 <1.0 <1.0 <1.0 <1.0 33 <0.1
41h Qtr 10/29/2013 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/29/2014 <1.0 <1.0 <1.0 <1.0 34 <0.1
2nd Qtr 5/23/2014 <1.0 <1.0 <1.0 <1.0 39.7 <0.1 3rd Qtr 8/26/2014 <1.0 <1.0 <1.0 <1.0 34 <0.1
41h Qtr 10/29/2014 <1.0 <1.0 <1.0 <1.0 34.9 <0.1 1st Qtr 3/17/2015 ,<1.0 <1.0 <1.0 <1.0 36.3 <0.1
2nd Qtr 6/11/2015 <1.0 <1.0 <1.0 <1.0 35.8 <0.1
3rd Qtr 9/9/2015 <1.0 <1.0 <1.0 <1.0 37.7 <0.1
4th Qtr 10/28/2015 <1 0 <1 0 <1 0 <1 0 34 7 <0.1
1st Qtr 3/22/2016 <1.0 <1.0 <1.0 <1.0 36.7 <0.1 Duplicate TW4-70 <1.0 <1.0.. <1.0 <1.0 37.7 0.119
2nd Qtr 6/8/2016 <1.0 <1.0 <1.0 <1.0 36.4 <0.1
Duplicate 7W4-70 <1.0 <1.0 <1.0 <1.0 37.7 <0.1
3rd Qtr 8/19/2016 <1.0 <1.0 <1.0 <1.0 35.7 <0.1
4th Qtr 10/31/2016 <1.0 <1.0 <1.0 <1.0 36.9 <0.1
1st Qtr 3/21/2017 <1.0 <1.0 <1.0 <1.0 33.7 <0.1 2nd Qtr 6/21/2017 <1.0 <1.0 <1.0 <1.0 37.2 <0.1
3rd Qtr 8/8/2017 <1.0 <1.0 <1.0 <1.0 30.1 <0.1
4th Qtr 10/12/2017 <1.0 <1.0 <1.0 <1.0 32.6 <0.1
1st Qtr 3/15/2018 <1.0 <1.0 <1.0 <1.0 39.4 <0.1
Duplicate TW4-70 <1.0 <1.0 <1.0 <1.0 39.3 <0.1 2nd Qtr 6/14/2018 <1.0 <1.0 <1.0 <1.0 34.4 <0.1
3rd Qtr 9/22/2018 <1,0 <1.0 <i .0 <1.0 41.2 <0.1 , 4th Qtr 10/29/2018 <1.0 <1.0 <1.0 <1.0 ......?A ..9,1 1st Qtr 3/19/2019 41.0 <1.0 <1.0 <1.0 33.3 <0.1
2nd Qtr 6/18/2019 <1.0 <1.0 <1.0 <1.0 36,5 <0.1 3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 41.2 <0.1
41h Qtr 12/18/2019 41.0 <1.0 <1.0 <1.0 36.3 <0.1 1st Qtr 3/18/2020 <1.0 <1.0 <1.0 <1.0 36 <0.1
Duplicate 1W4-75 <1.0 <1.0 <1.0 <1.0 34.8 <0.1 2nd Qtr 6/12/2020 <1.0 <1.0 <1.0 <1.0 35.6 <0.1
3rd Qtr 9/18/2020 <1.0 <1.0 <1.0 <1.0 34.7 <0.1 418 Qtr 11/4/2020 <1.0 <1.0 <1.0 <1.0 31.3 <0.1 Duplicate TW4-65 <1.0 <1.0 <1.0 <1.0 35.9 <0.1
(1) VOCs were resampled because laboratory missed holding time.
toth north and south wild life ponds no longer receiving water NA = not analyzed Shaded indicates concentrations exceeding GWQS.
TABLE 1 (4 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020 Chloroforrn Contamination investigation
DUSA White Mesa Mill
Twa-lichloroforrn purnpIng MI started in 1116/15) Sampling Event Parameter (GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate 4- Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA 2,700 NA NA NA 9.1
2nd Qtr 5/25/2005 NA 3,080 NA NA NA 10.6 3rd Qtr 8/31/2005 <10 2,900 <10 <10 NA 9.8
4th Qtr 12/7/2005 <50 2,400 <50 <50 52 9.7
1st Qtr 3/9/2006 <50 2,700 <50 050 49 9.4
2nd Qtr 6/14/2006 <50 2,200 <50 <50 48 9.6
3rd Qtr 7/20/2006 <50 2,840 <50 <50 51 41h Qtr 11/8/2006 1.4 ...,60 <1.0 <1.0 47 .......9., 1st Qtr 2/28/2007 1.2 1,9.60 <1.0 <1.0 47 8.6 2nd Qtr 6/27/2007 1.4 1,900 <1.0 <1.0 45 9
3rd Qtr 8/15/2007 1.3 2,300 <1.0 <1.0 43 8.4
4th Qtr 10/10/2007 1.3 2,,000 <to <1.0 43 . 7.8
1st Qtr 3/28/2008 1.3 2,000 <1.0 <1.0 39 7.6
2nd Qtr 6/25/2008 1.1 1,900 <1.0 <1.0 39 8.68
3rd Qtr 9/10/2008 1.3 1,700 <1.0 <1.0 35 8.15
4th Qtr 10/15/2008 1.3 1,700 <1.0 <1.0 41 9.3
1st Qtr 3/11/2009 1.1 1,7.60 <1.0 <1.0 37 7.5
2nd Qtr 6/23/2009 1 1,500 <1.0 <1.0 37 6.9
3rd Qtr 9/14/2009 <1.0 1,700 <1.0 <1.0 36 7.3
4th Qtr 12/29/2009 <1.0 1400 <1.0 <1.0 41 _64 lst Qtr 3/3/2010 <1.0 1,3130 <1.0 <1.0 35 7.1
2nd Qtr 6/14/2010 1.2 1,600 <1.0 <1.0 40 6.8 3rd Qtr 8/18/2010 1 1,600 <1.0 <1.0 35 6.7
4th Qtr 10/15/2010 <1.0 AN() <to <1.0 40 6.6
1st Qtr 2/24/2011 <1.0 1 300 , . <1 0 <1.0 41 6.6
2nd Qtr 6/1/2011 <1.0 1,200 <1.0 <1.0 35 6.6
3rd Qtr 8/18/2011 <1.0 1 300 , <1.0 <1.0 36 6.8
4th Qtr 11/29/2011 <1.0 1 500 <1.0 <1.0 40 6.6 1sttiir (2) 1/24/2012 <1.0 _ 1,300 <1.0 <1.0 38 6.8
2nd Qtr 6/14/2012 <1.0 1,000 <1.0 <1.0 42 7.1 3rd Qtr 9/28/2012 <1.0 1,000 <1.0 <1.0 39 5.0
4th Qtr 10/4/2012 <1.0 1100 <1.0 <1.0 40 6.5
1st Qtr 2/13/2013 3.66 1,320 <1.0 <1.0 37.6 6.96
2nd Qtr 6/19/2013 <1.0 1,100 <1.0 <1.0 39.1 6.87
3rd Qtr 9/3/2013 <1.0 1,150 <1.0 <1.0 37.6 7.12
4th Qtr 11/14/2013 <1.0 .1280 <1.0 <1.0 36.5 7.08
1st Qtr 2/5/2014 5.47 1,060 <1.0 <1.0 38.9 7.74
2nd Qtr 5/23/2014 4.77 1,020 <1.0 <1.0 37.4 6.93
3rd Qtr 8/27/2014 <1.0 845 1.4 <1.0 38 4.80 41h Qtr 10/29/2014 <1 0 - 1 140 <1 0 <1 0 38 7 6.31
1st Qtr (2) 3/9/2015 <1.0 1,130 <1.0 <1.0 38.3 7.06
2nd Qtr 6/8/2015 <1.0 1,260 <1.0 <1.0 40.3 6.07
3rd Qtr 8/31/2015 <1.0 1,060 <1.0 <1.0 45.9 6.28
4th Qtr 10/19/2015 <1.0 1 040 <1 0 <1 0 38.5 1 55
1st Qtr 3/9/2016 <1.0 974 <1.0 <1.0 41.7 0.148
2nd Qtr 5/23/2016 <1.0 1,140 <1.0 <1.0 44.4 0.138 3rd Qtr 7/25/2016 <1.0 1,160 <1.0 <1.0 44.7 5.49
41h Qtr 10/13/2016 <1.0 1,330 <1.0 <1.0 44.2 ......0.16 1st Qtr 3/8/2017 <1.0 519 <1.0 <1.0 41.5 4.4
2nd Qtr 6/13/2017 <1.0 977 <1.0 <1.0 41.8 5.74 3rd Qtr 7/26/2017 <1.0 958 <1.0 <1.0 42.8 5.04
4th Qtr 10/11/2017 <1.0 556 <1.0 <1.0 38.5 5.78 DWmRC.spla sampls. .6 810 <12 23 J 42 0.17 1st Qtr (3) 3112/2018 :71.0 _ 70.4 <1.0 <1.0 45.8 4.84
2nd Qtr 6/8/2018 <1.0 942 <1.0 <1.0 42.0 4.38
3rd Qtr 8/22/2018 <1.0 1,010 <1.0 <1.0 47.3 4.30 4th Qtr 10/22/2018 <1.0 752 <1.0 <1.0 43.2 4.57
DWMRgmlit sem& <5.0 210 <5.0 <5.0 1st Qtr 3/8/2019 <1.0 87.2 <1.0 <1.0 .46.6 .4.1
2nd Qtr 6/5/2019 <1.0 1,040 <1.0 <1.0 44.8 1.43
3rd Qtr 9/4/2019 <1.0 894 <1.0 <1.0 46 1.65
4th Qtr 12/10/2019 <1.0 _ 1 070 <1.0 <1.0 44.2 a91
1st Qtr 2/19/2020 <1.0 1,190 <1.0 <1.0 47.5 4.67
2nd Qtr 5/27/2020 <1.0 499 <1.0 <1.0 46.4 0.44
3rd Qtr 9/4/2020 <1.0 1,060 <1.0 <1.0 43.7 2.22 410 Qtr 10/28/2020 <1 0 924 <1.0 <1.0 41.9 4.30
ponds no lOruer rece, 0.2W4-1 concerted to a oNow,orm_pum.EIL9 well started in 1/14/15
(3) croroform purainzie-l171874-41 started In May 2018
NA = not analyzed Shaded indicates concentrations exceeding GWQS.
Bold and italics indicates the MDL exceeded the GWOS. J = Approximated value
TABLE 1 (5 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TVV4-2 (chloroform Nmpiogm Oarting 1/14/151
Sarnpling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 2nd Qtr 5/25/2005
3rd Qtr 8/31/2005
415 Qtr 12/7/2005
1st Qtr 3/9/2006
2nd Qtr 6/14/2006
3rd Qtr 7/20/2006
4th Qtr 11/8/2006
151 Qtr 2/28/2007
2nd Qtr 6/27/2007
3rd Qtr 8/15/2007
4th Qtr 10/10/2007
1st Qtr 3/28/2008
2nd Qtr 6/25/2008
3r4 Qtr 9/10/2008
4th Qtr 10/15/2008
11/18/2008
151 Qtr 3/11/2009
2nd Qtr 6/23/2009
3rd Qtr 9/14/2009
4th Qtr 12/29/2009
1st Qtr 3/3/2010
2nd Qtr 6/14/2010
3rd Qtr 8/18/2010
4th Qtr 10/15/2010
1st Qtr 2/24/2011
2nd Qtr 6/2/2011
3rd Qtr 8/17/2011
4th Qtr 11/29/2011 lila' (2/ 1/24/2012
2nd Qtr 6/14/2012
3rd Qtr 9/4/2012
4th Qtr 10/4/2012
1st Qtr 2/13/2013
2nd Qtr 6/19/2013
3rd Qtr 9/3/2013
41h Qtr 11/14/2013
1st Qtr 2/6/2014 2nd Qtr 5/23/2014
3rd Qtr 8/27/2014
4th Qtr 10/30/2014
1st Qtr (2) 3/9/2015
2nd Qtr 6/8/2015
3rd Qtr 8/31/2015
44r.i...91!"..... .101.1.21.2.9.1.5r. 1 st Qtr 3/9/2016
2nd Qtr 5/23/2016
3rd Qtr 7/25/2016
4th Qtr 10/12/2016
1st Qtr 3/8/2017
2nd Qtr 6/13/2017
3rd Qtr 7/26/2017
4th Qtr 10/11/2017
DWMRC split sample
DWMRC dgVicete1W4-50
1st Qtr 3/12/2018
2nd Qtr 6/8/2018
3rd Qtr 8/22/2018
ath Qtr 10/22/2018
1st Qtr 3/8/2019
2nd Qtr 6/5/2019
3rd Qtr 9/4/2019
41h Qtr 12/10/2019
1st Qtr 2/19/2020
2nd Qtr 6/10/2020 3rd Qtr 9/4/2020
41h Qtr 10/28/2020
,
• •
.
i
'
i:

1
:
.

L:
n
.
.
.
^...
"—AA
A
±
1:

.1L
'.
.
.
A...'1
11"—
'1
.
.
'1
A
L
'..L1
A.
."
z
,
.••

:.
-
•
.
.
.
• •
,A i

A
1A

A

F- F-

66
6
6
6
6
6
6',.,
D
o
o
i

0
0
0
0
,
00

'E
D
O
• ••
-
.

.
,

•
•
i

: E : •
•
. ,:

:

- .

. ••••
•••• ! E i : :
-.
:

:
.
.
.
. .
•
. - . :
•' .
. .

.
: .
•
:
: : ::
:

.

:
:
•

.
. : .
•
. 2
:
. .

•
: : : :

i
•
! . ' :
: ' : :

: .
- : •
:
•
:
:
:

'
. :
.••
.
:

i • .
: : . E
2 :

. :
. . : : :
•
,
• • . • !
i E : . :

: . i -.. -, CO

2 CO N IV

C
11
2
•
.

•
•
E . . i
.
. •
:
I ..P.
'"

4,
.
2,-)-
v6
:
-...
2
-„,..
6.,
,
-A!
,,,
,!
,,
,
.
.
,,
,
,
:
!
-,i.
i.n.co
u
,
i
I
.•• .••
,
•
#N/A
3,700 3,750
3,900
1500
3,880
3,200
4,120
1,420
2,3-80
3,000
340 3290
3,300
3,100
2,800
.1200
3,100
2,800
3,000
1,62.9 2,600
3,300
3,300
3 000
3,100
3,000
2,400
3,900
2,500
2,500 2,900
.11.00
3,580
3,)10
3,480
3J40
3,180 2,930
3,170
3 580
1,840
1,650
1,060
2 070
1,970
2,070
1,780
1600
1,570
1,940
1,310
1,610
1,200 1200,
764
949
980
822
1,040
1,360
797
934
1,880
1,070 1,260 1 130
NA NA
<10
<50
<50
<50
<50
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
NA
<2.0
<1.0
<1.0
<1.0
<1.0 <1 0
<1.0
<1.0
<1 0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
2
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1 0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<30
<30
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1 0
<1.0
<1.0 <1.0 <1.0
3.6
2.6
NA NA <10
<50
<50
<50
<50
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
NA
<2.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1 0
<1.0
<1.0 <1.0 <1.0
68 J
60 J
NA NA
NA
56
56
56
54
55
54
50
49
51
48
46
42
47
NA 46
44
43
46
42
43
43
41
46
42
48
49
49
52
76
49
46
46.9
44.9
43.9
45.9 454
45
45.5
44.9
48.1
50
41.9 43.4
43.8
42 9
44.3
43.1
43.6
43.2 43.5
44
43
44.4
41.3
44.3
41.7
40.4
39.8
40.8
41.5
42.1
40.6 41.3
38 7
N/A
7.7 8.6
8.0
7.8
7.5
7.1
7.4
7.6
7.3
7.8
7.3
6.9
6.9
7.4
7.1
8.0
................. 6.5
6.4
6.6
6.4 6:6
8.7
6.6
......6:5 7..6 6.8
6.0
7.0
7.1
7.7
4.0
7.6
8.1
7.51
9.3 8.39
7.87
9.11
6.2
8.45
5.32
4.3
3.76
5.18 5.30
5.67
4.07
6.07
4.74
4.90
5.08 3.25
4.00
2.94
3.50
4.83
3.52
3.92
4.38
4.79
3.40
6.07
3.62 3.35 2 34
(1) As of March 2012 both nohth and south »»lc pCnd5 ,onaer rec,IvIng vvater
2) TW4-2 and 1W4-11 converted to a chloroform pawing well started in 1/14/15
NA and #N/A(for graph use)= not analyzed
Shaded indicates concentrations exceeding GWQS.
Bold and italics indicates the MDL exceeded the GWQS. J = Approxirnated value
TABLE 1 (6 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020 Chloroform Contamination investigation
DUSA White Mesa Mill
TW4-3
Sampling Event
Parameter
(GWQS) Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chlonde
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA <1 0 NA NA NA 3 5 2nd Qtr 5/25/2005 NA <1 0 NA NA NA 3 7
3rd Qtr 8/31/2005 <1 0 <1 0 6 4 <1 0 NA 3 5
4th Qtr _ 12/7/2005 0 .<1 <1 0 <1 0 <1 0 .. 26 3 3
1st Qtr 3%9/2006 <1 a <1 0 2 3 <1 0 26 3 3
2nd Qtr 6/14/2006 <1 0 <1 0 1 6 <1 0 26 7 1
3rd Qtr 7/20/2006 <1 0 <1 0 2 2 <1 0 26 2 9
41h Otr 11/8/2006 <1 0 • <1 0 <1 0 <1 0 23 1 5 1st Qtr 2/28/2007 <1 0 <1 0 <1 0 <1 0 22 3 1
20d Qtr 6/27/2007 <1 0 <1 0 <1 0 <1 0 23 3 3 3rd Qtr 8/15/2007 <1 0 <1 0 <1 0 <1 0 24 3 1
4th.Qtr 10/10/2007 <1 0 _ <1 0 <1 0 <1 0 27 ? § lit Qtr 3/28/2008 <1- 0 <1 0 <1 0 <1 0 21 2 8
2nd Qtr 6/25/2008 <1 0 <1 0 <1 0 <1 0 19 2 9 3rd Qtr 9/10/2008 <1 0 <1 0 <1 0 <1 0 19 2 7
41h Qtr 10/15/2008 <1 0_ <1 0 <1 0 <1 0 22 2 6
1st Qtr 3/4/2009 <1-0 <1 0 <1 0 <1 0 21 2 5 2nd Qtr 6/23/2009 <1 0 <1 0 <1 0 <1 0 20 2 9
3rd Qtr 9/14/2009 <1 0 <1 0 <1 0 <1 0 21 2 8 41h Qtr 12/29/2009 <1 0 <1 0 <1 0 <1 0 22 2 6
1st Qtr 2/23/2010 <1 0 <1 0 <1 0 <1 0 23 2 8 2nd Qtr 6/14/2010 <1 0 <1 0 <1 0 <1 0 24 3 0
3rd Qtr 8/10/2010 <1 0 <1 0 <1 0 <1 0 22 3 1 4th Qtr 10/15/2010 <1 0 <1 0 <1 0 <1 0 _26 3 3
lst Qtr 2/15/2011 <1 0 <1 0 <1 0 <1 0 23 3 5
2nd Qtr 5/25/2011 <1 0 <1 0 <1 0 <1 0 23 3 7
3rd Qtr 8/17/2011 <1 0 <1 0 <1 0 <1 0 23 4 0
4th Qtr 11/14/2011 <1 0 <1 0 <1 0 <1 0 23 4 4
1st Otr (2) 1/17/2012 <1 0 <1 0 <1 0 <1 0 21 7 1
2nd Qtr 5/31/2012 <1 0 <1 0 <1 0 <1 0 24 4 4
3rd Qtr 8/28/2012 <1 0 <1 0 <1 0 <1 0 25 4 9 4th Qtr 10/3/2012 <1 0 <1 0 <1 0 <1 0 25 4 8
1st Qtr 2/7/2013 <1 0 <1 0 <1 0 <1 0 23 7 5 05 2nd Qtr 6/28/2013 <1 0 <1 0 <1 0 <1 0 23 8 5 83
3rd Qtr 9/3/2013 <1 0 <1 0 <1 0 <1 0 25 4 90
4th Qtr 11/8/2013 <1 0 <1 0 <1 0 <1 0 24 1 5 89
1s1 Qt-r 1/22/2014 «1 0 <1 0 <1 0 <1 0 24 9 6 66
2nd Qtr 5/21/2014 <1 0 <1 0 <1 0 <1 0 24 4 6 01
3rd Qtr 8/13/2014 <1 0 <1 0 <1 0 <1 0 26 5 30
41h Qtr 10/23/2014 <1 0 <1 0 <1 0 <1 0 26 7. 6 07
1st Qtr 3/11/2015 <1 0 <1 0 <1 0 <1 0 26 2 6 64
2nd Qtr 6/10/2015 <1 0 <1 0 <1 0 <1 0 27 5 5 71
Duplicate TW4-65 <1 0 <1 0 <1 0 <1 0 27 5 3 94
3rd Qtr 8/13/2015 <1 0 <1 0 <1 0 <1 0 27 4 3 88
4th Qtr 10/21/2015 51 0 <1 0 <1 0 <1 0 25 6 5 37
1st Qtr 3/15/2016 <To— — <1 0 <1 0 <1 0 32 8 5 83
2nd Qtr 5/25/2016 <1 0 <1 0 <1 0 <1 0 27 9 5 65
3rd Qtr 7/27/2016 <1 0 <1 0 <1 0 <1 0 26 5 6 10
4th Qtr 10/19/2016 <1 0 <1 0 <1 0 <1 0 29 5 ._ 6 00
151 Qtr 3/14/2017 <1 0 <1 0 <1 0 <1 0 28 1 6 18
2nd Qtr 6/14/2017 <1 0 <1 0 <1 0 <1 0 28 7 6 36
3rd Qtr 7/27/2017 <1 0 <1 0 <1 0 <1 0 28 5 6 36
Duplicate 1W4-65 <1 0 <1 0 <1 0 <1 0 28 9 6 24 4th Qtr 10/11/2017 <1 0 <1 0 <1 0 <1 0 25 9 6 32
1st Qtr 3/14/2018 <1 0 <1 0 <1 0 <1 0 29 6 6 46
Duplicate TW4-65 <1 0 <1 0 <1 0 <1 0 29 5 6 31
2nd Qtr 6/8/2018 <1 0 <1 0 <1 0 <1 0 26 1 6 52
3r5 Qtr 8/29/2018 <1 0 <1 0 <1 0 <1 0 31 0 5 53 Duplicate TW4-65 <1 0 <1 0 <1 0 <1 0 31 0 5 44
4th Qtr 11/30/2018 <1 0 <1 0 <1 0 <1 0 27 4 5 85 Duplicate 1W4-65 <1 0 <1 0 <1 0 <1 0 26 2 5 77
1st Qtr 3/13/2019 <1 0 <1 0 <1 0 <1 0 25 5 5 6-2
2nd Qtr 6/13/2019 <1 0 <1 0 <1 0 <1 0 27 4 6 68
Duplicate TW4-65 <1 0 <1 0 <1 0 <1 0 25 9 6 60
3rd Qtr 9/11/2019 <1 0 <1 0 <1 0 <1 0 26 0 5 12
Duplicate TW4-65 <1 0 <1 0 <1 0 <1 0 22 1 5 76
4th Qtr 12/12/2019 0 .<1 <1 0 <1 0 <1 0 28 5 91 1st Qtr 3/17/2020 <1 0 <1 0 <1 0 <1 0 27 7 6 15
Duplicate TW4-65 <1 0 <1 0 <1 0 <1 0 26 6 38 2nd Qtr 6/10/2020 <1 0 <1 0 <1 0 <1 0 26 2 6 53
Duplicate 1W4-65 <1 0 <1 0 <1 0 <1 0 26 7 6 63
3rd Qtr 9/17/2020 <1 0 <1 0 <1 0 <1 0 25 9 6 36 4th Qtr 11/4/2020 <1 0 <1 0 <1 0 <1 0 24 9 6 02
NA = not analyzed Shaded indicates concentrations exceeding GWQS
TABLE 1 (7 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4.4 (chloroform pumping well stared in 1st ntr 2010)
Sarnpling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate -i- Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA 3,100 NA NA NA 10.0
2nd Qtr 5/25/2005 NA 2,400 NA NA NA 11.3
3rd Qtr 8/31/2005 <10 3,200 <10 <10 NA . . 9.9
4th Qtr 12/7/2005 <50 2,800 <50 <50 54 10.2
1st Qtr 3/9/2006 <50 2,900 <50 <50 51 9.5
2nd Qtr 6/14/2006 <50 2,600 <50 <50 48 8.6
3rd Qtr 7/20/2006 <50 , , 2,850 <50 <50 50 9.7
4th Qtr 11/8/2006 1.7 2670 <1.0 <1.0 49 10.1
1st Qtr 2/28/2007 1.5 2,200 <1.0 <1.0 49 9.0
2nd Qtr 6/27/2007 1.7 2,400 <1.0 <1.0, 47 9.4
3rd Qtr 8/15/2007 1.5 2,700 <1.0 <1.0 45 9.5
4th Qtr 10/10/2007 1.5 2.,§90 <1.0 <1.0 47 9.5 1st Qtr 3/28/2008 1.6 2,800 <1.0 <1.0 43 9.2
2nd Qtr 6/25/2008 1.5 2,500 <1.0 <1.0 42 10.8 3rd Qtr 9/10/2008 1.4 2,200 <1.0 <1.0 39 8.8
4th Qtr 10/15/2008 NA #N/A NA NA 44 10.1
1st Qtr 11/18/2008 <2.0 2,600 <2.0 <2.0 NA #N/A
1st Qtr 3/4/2009 1.2 2,200 <1.0 <1.0 37 10.2
2nd Qtr 6/23/2009 1.2 1,800 <1.0 <1.0 34 8.2
3rd Qtr 9/14/2009 1.1 2,000 <1.0 <1.0 39 , 8.4
4t8 Qtr 12/29/2009 1.1 956,<1.0 <1.0 41 7.6
1st Qtr (2) 2/17/2010 1 1,703<1.0 <1.0 48 6.6
2nd Qtr 6/14/2010 1.2 1,700 <1.0 <1.0 . 35 , 7,6
3rd Qtr 8/10/2010 1.3 2,100 <1.0 <1.0 36 7.3 41h Qtr 10/15/2010 1.3 1,700 <1.0 <1.0 38 7.1
1st Qtr 2/23/2011 1.4 1,800 <1.0 <1.0 41 7.0
25d Qtr 6/1/2011 1.2 1,700 <1.0 <1.0 35 7.0
3rd Qtr 8/17/2011 <1.0 1,500 <1.0 <1.0 40 6.6
41h Qtr 11/16/2011 1 1,500 <1.0 <1.0 39 7.0 1st Qtr (1 i 1/23/2012 <1.0 1,200 <1.0 <1.0 38 7.1
2n7I -(5- - - 6/6/2012 <1.0 1,500 <1.0 <1.0 _ 43 7 1
3rd Qtr 9/4/2012 1.2 1,600 <1.0 <1.0 39 7.1
4th Qtr 10/3/2012 1 .1,400 <1.0 <1.0 38 7.0
1st Qtr 2/11/2013 1 1,460 <1.0 <1.0 39 7.36
2nd Qtr 6/29/2013 <1.0 1,330 <1.0 <1.0 39.6 6.30
3rd Qtr 9/3/2013 1.2 1,380 <1.0 <1.0 38.8 7.22
41h Qtr 10/23/2013 5.3 1,360 <1.0 <1.0 43.9 7.84
lst Qtr 1/27/2014 3.88 1,260 <1.0 . <1.0 37.4 7.28
2nd Qtr 5/19/2014 4.94 1,220 <1.0 , <1.0 47.5 5.91 „ 3rd Qtr 8/11/2014 4.94 1,320 7.1 <1.0 40 5.3
41h Qtr 10/21/2014 .._ ........ _ <1.0 _. 1,130 <1.0 <1.0 40 7.02
1st Qtr (4) 3/9/2015 1.05 1,350 <1.0 <1.0 37.6 7.7
2nd Qtr 6/10/2015 <1.0 1,280 <1.0 <1.0 41.3 6.33
3rd Qtr 8/31/2015 <1.0 1,220 1.72 <1.0 45.8 6.45
4t11 Qtr 10/19/2015 <1.0 119_0 <1.0 <1.0 38.5 6.27
1st Qtr 3/9/2016 <1.0 1,195- <1.0 <1.0 39.7 6.7
2nd Qtr 5/23/2016 1.21 AJ80 <1.0 <1.0 41.9 6.56
3rd Qtr 7/27/2016 <1:0 1 380 <1.0 <1.0 40.2 7.22
4t8 Qtr 10/13/2016 <1.0 1,430 <1.0 <1.0 40.3 6.77
1st Qtr 3/8/2017 <1.0 1,290 <1.0 <1:0 , 41.7 6.87 2nd Qtr 6/13/2017 <1.0 1,290 <1.0 <1.0 40.7 , 7.06
3rd Qtr 7/26/2017 <1.0 1,290 <1.0 <1.0 40.5 6.47 4th Qtr 10/11/2017 <1.0 1,120 <1.0 <1.0 40.7 6.90
1st Qtr 3/12/2018 <1.0 1 160 <1.0 <1.0 42.2 6.12
2-n7 'CR() 6/8/2018 <1.0 1,050 <1.0 <1.0 39.0 6.34
3rd Qtr 8/22/2018 <1.0 1,030 <1.0 <1.0 44.6 6.10
41h Qtr 11/28/2018 <1.0 1,140 <1.0 <1.0 41,4 6.02
1st Qtr 3/8/2019 <1.0 1,050 <1.0 <1.0 38.3 7.26
2nd Qtr 6/5/2019 <1.0 1,070 <1.0 <1.0 38.5 10..40
3rd Qtr 9/4/2019 <1.0 989 <1.0 <1.0 39.4 6.32
41h Qtr 12/10/2019 <1.0 1.,140 <1.0 <1.0 40.4 6.52
1st Qtr 2/19/2020 <1.0 1,100 <1.0 <1.0 43.4 4.58
2nd Qtr 5/27/2020 <1.0 1,140 <1.0 <1.0 46.1 7.25
3rd Qtr 9/4/2020 <1.0 1,110 <1.0 <1.0 40.0 7.04
4th Qtr 10/28/2020 <1.0 979 <1.0 <1.0 38.6 . ,_ 6,77
(2) TW4-4 converted to a Chloroform purainueell stared in 1 t.str 2010
`AJ4-41 installed as a Chlonatorte au-nen-1g well stared In May a018
NA and #N/A(for graph use) = not analyzed
Shaded indicates concentrations exceeding GWQS.
Bold and italics indicates the MDL exceeded the GWQS
TABLE 1 (8 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-5
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate . Nitrite
(10 mg/L)
1st Qtr 3/16/2005
2nd Qtr 5/25/2005
3rd Qtr 8/31/2005
41h Qtr 12/7/2005 1st Qtr 3/9/2006
2nd Qtr 6/14/2006
3rd Qtr 7/20/2006
4th Qtr 11/8/2006
1st Qtr 2/28/2007
2nd Qtr 6/27/2007
3rd Qtr 8/15/2007
4th Qtr 10/10/2007
1st Qtr 3/28/2008
2nd Qtr 6/25/2008
3rd Qtr 9/10/2008
41h Qtr 10/15/2008
1st Qtr 3/4/2009 2nd Qtr 6/23/2009
3rd Qtr 9/14/2009
4th Qtr 12/29/2009
1st Qtr 2/25/2010
2nd Qtr 6/14/2010
3rd Qtr 8/11/2010
4th Qtr 10/15/2010
1st Qtr 2/22/2011
2nd, qtr, 5/26/2011
arci Qir 8/7/2011
4th Qtr 11/16/2011

... (1) 12/7/2011 1st Qtrr(2( 1/18/2012
Tn-ti "ofF - - - -67e72012
3rd Qtr 9/11/2012
4th Qtr 10/4/2012
1st Qtr 2/13/2013
2nd Qtr 6/13/2013
3rd Qtr 9/5/2013
4th Qtr 11/13/2013
1st Qtr 1/30/2014
2nd Qtr 5/22/2014
3rd Qtr 8/14/2014
4th Qtr 10/13/2014
1st gtr 3/12/2015
Duplicate TV/4-70 2nd Qtr 6/10/2015
3rd Qtr , , 9/10/2015 „ :4iri air 10/28/2015
1st Qtr 3/17/2016
2nd Qtr 5/23/2016
3rd Qtr 8/3/2016
4th Qtr (3) 10/26/2016 DuE!icate TW4-75
1st Qtr 3/15/2017
2nd Qtr 6/15/2017,
3rd Qtr 8/8/2517
4th Qtr 10/11/2017
DWMRC split sample 1st Qtr 3/12/2018
2nd Qtr 6/13/2018
3rd Qtr 8/30/2018
Duplicate TW4-70
4th Qtr 11/28/2018
pupacate TW4-70
1st Qtr 3/16/2019
2nd Qtr 6/13/2019
3rd Qtr 9/11/2019
Duplicate TW4-70
4th Qtr 12/14/2019
Dugheate TV/4-70
1st Qtr 3/17/2020
Duplicate TW4-70 2nd Qtr 6/11/2020
3rd Qtr 9/18/2020
41h Qtr 11/4/2020
NA
NA
<2.5
<2.5 <2.5
<2.5
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0 , , <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
NA
<1.0
<1.0
".170
<1.0 <1.0
<1.0
<1.0
<1.0,
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0 „ . <1.0
<1.0
<1.0
<1.0
<1.0_ <1 0
<1.0
<1.0
<1.0
<1.0
<0.19 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
*N/A
120
113 82
63
66
51
53.7
47.1
35
26
9.2
9.4
11
9.3
11
10
12 13
12
8.5
13
12
12
11
10
9
10
7.9
7.6
8.4
12.0
8.0
10.8
11.2
11.6
14.4
12.5
13.4
12.0
145 13.8
13.8
13.3
12.9
11.0
11.0
13.6
10.8
9.9 12.0
12.E
14.6
14.6
13.8
12 15.2
13,6
15.4
15.3
15.6
16.2
14.1 15.8
14.6
13.6
15.7
16.0
14.8
14.8 15.4
14.8
15.6
NA
NA
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
NA
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
1.07
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<0.3 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
5.8
2.5
3.1
3.1
NA
NA
<2.5
<2.5
<2.5
<2.5
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
NA
<1 0 < .0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0,
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<0.32 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
NA
NA
NA
56
52
51
54
..55.
57
45
38
39 ....... 36
37
3.4 37
34
37 48
41
43
28 38
41
34
35
37
30
NA 221
39 „... 37
38
34.3
, 36,5
39.1
41.1
40.5

„ . 51.4
44
45.1 45.1
46.4
47.3
52.2
43.6
44.7
45.9
44.6
47.8
49.5
44.7
47.3
48.6
42.5
47 51.2
47.3
54.7
55.9
49.8 48.5
47.6
. 43.-3 46.1
45.8
53.1
52.5
48.3
, 48.4 49.5
47.0
50.2
*N/A,
7.0
4.9
3.7 6.0
6.0
6.0
5.9
6.7 2.9 „„.„„.. 7.8 7.0
7.7
8.2
7.4 8.7
7.9
9.3
7.6
7.5
8.3
7.5 6.8
7.1
.12
7.0
7.2
7.5
6.0
5.8
8.0
8.1
7.7
8.24
10.70
7.79
7.75
9.16
7.78
7.2
8.31 9.32
8.81
7.08 8.1
8.03
10.2
8.98
8.49
8.32
8 34
8.49
8.52
8.52
8.57
8.6
8.36
9.24
7.34
7.28
7.67
70
7.38
7.62
7.04
6.89
6.97
7.29
7.10
7.72
7.83
6.37
._ 6,19
(1) VOCs were resampled becau e laboratory missed holding time
,3) chloroform goading well 7W4-39 sta ed In /20/16
NA and #N/A(for graphs) - not analyzed Shaded indicates concentrations exceeding GWOS.
TABLE 1 (9 of 31) Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-6
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L) 1st Qtr 3/16/2005 NA <1.0 NA NA NA 0.2
2nd Qtr 5/25/2005 NA 2.5 NA NA NA 0.4 3rd Qtr 8/31/2005 , <1.0 10 2.8 <1.0 NA 0.8
4th Otr 12/7/2005 <1.0 17 1.3 <1.0 32 0.9 1st Qtr 3/9/2006 <1.0 31 <1.0 <1.0 31 1.2
2nd Qtr 6/14/2006 <1.0 19 <1.0 <1.0 30 1.0
3rd Qtr 7/20/2006 <1.0 11 <1.6 , <1.0 37 0.6 4t5 Qtr 11/8/2006 <1.0 42.8 <1.0 <1.0 65 1.4
1st Qtr 2/28/2007 <1.0 46 <1.0 <1.0 32 .1.8 2nd Qtr 6/27/2007 <1.0 11 <1.0 <1.0 38 0.6
3rd Qtr 8/15/2007 <1.0 18 <1.0 <1.0 36 0.7 41h Qtr 10/10/2007 <1.0 18 <1.0 <1.0 35 _AA lst Qtr 3/28/2008 <1.0 52 <1.0 <1.0 33 .1..1 2nd Qtr 6/25/2008 <1.0 24 <1.0 <1.0 35 0.9
3rd Qtr 9/10/2008 <1.0 39 <1.0 <1.0 , 35 1.1 4th Qtr 10/15/2008 <1.0 37 <1.0 <1.0 33 _IP. lst Qtr 3/4/2009 <1.0 81 <1.0 <1.0 35 2.2 2nd Qtr 6/23/2009 <1.0 120 <1.0 <1.0 37 . 2.,7 3rd Qtr 9/14/2009 <1.0 280 <1.0 <1.0 37 5.0
4t9 Qtr 12/29/2009 <1.0 250 <1.0 . <1.0 41 6.1 1st Qtr (5) 2/25/2010 <1.0 - 1000 <1.0 <1.0 45 1.8
2nd Qtr 6/14/2010 <1.0 590 <1.0 <1.0 33 2.5 3rd Qtr 8/11/2010 <1.0 630 <1.0 <1.0 31, , 3.9 41h Qtr 10/15/2010 <1.0 420 <1.0 <1.0 41 4.3 1st Qtr 2/22/2011 <1.0 47 <1.0 <1.0 40 0.7 2nd Qtr 5/26/2011 <1.0 9.6 <1.0 <1.0 , 42 0.3 3rd Qtr 8/7/2011 <1.0 16 <1.0 <1.0 39 0.3 4th Qtr 11/16/2011 NA #N/A NA NA 36 0.8 (1) 12/7/2011 <1.0 21 <1.0 <1.0 #N/A (2) 11/18/2011 <1.0 50 <1.0 <1.0 33 'cif titiF(4) 1/18/2012 <1.0 38 <1.0 <1.0 38 0.
2nd Qtr 6/6/2012 <1.0 4.7 <1.0 <1.0 40, 0.2 3rd Qtr 9/11/2012 <1.0 6.9 <1.0 <1.0 21 0.1 41h Qtr 10/4/2012 <1.0 9 <1.0 <1.0 41 0.2 1st Qtr 2/13/2013 <1.0 6.89 <1.0 <1.0 40.4 0 2 2nd Qtr 6/13/2013 <1.0 4.86 <1.0 <1.0 37.9 0.2 3rd Qtr 9/5/2013 <1.0 5.93 <1.0 , <1.0 40.6 0.2
4th Qtr 11/13/2013 <1.0 5.51 <1.0 <1.0 40.2 1.5 1st Qtr 1/29/2014 <1.0 5.7 <1.0 <1.0 40.6 0.2
2nd Qtr 5/22/2014 <1.0 10.3 <1.0 .. <1.0 37 0.3 3rd Qtr 8/14/2014 <1.0 202 <1.0 <1.0 40 4.2 (3) 9/24/2014 <1.0 260 <1.0 <1.0 #N/A 4t5 Qtr 10/29/2014 <1.0 723 <1.0 <1.0 41.
1st Qtr 3/12/2015 <1.0 1,180 <1.0 <1.0 41.2 5.6
2nd Qtr 6/10/2015 <1.0 1,040 <1.0 <1.0 41.6 5.9 3rd Qtr 9/10/2015 <1.0 1,040 <1.0 <1.0 47 6.8 4p1.9L... - 1 st Qtr 10/29/2015 3/22/2016 <1.0 <1.0 --..._ 843 _ 834 <1.0 <1.0 ..... _.<1,0 .. ..... 7 Z1 0 40.2 42.3 5.6 6.79
2nd Qtr 6/8/2016 <1.0 486 <1.0 <1.0 44.1 3 19
3r5,Q1r 7/27/2016 <1.0 433 <1.0 <1.0 42.2 3.85 4th Qtr 10/26/2016 <1.0 301 <1.0 <1.0 46.1 3.74
1st Qtr 3/16/2017 <1.0 288 <1.0 <1.0 42.1 3 15 2nd Qtr 6/21/2017 01.0 239 <1.0 <1.0 42.6 2.42 , 3rd Qtr 8/8/2017 <1.0 129 <1.0 <1.0 42.9 1.71 4th Qtr 10/11/2017 <1.0 121 <1.0 <1.0 1st Qtr 3/20/2018 <1.0 159 <1.0 <1.0 - -El. L i.766
2nd Qtr (6) 6/14/2018 <1.0 74.9 <1.0 <1.0 40.2 1.48
3rd Qtr 9/5/2018 <1.0 53.2 <1.0 ..„ .„ <1.0 44 1.18 4th Qtr 12/12/2018 <1.0 37.0 <1.0 <1.0 20.0 0.90 1st Qtr 3/19/2019 <1.0 23.2 <1.0 <1.0 41 0.755
2nd Qtr 6/13/2019 <1.0 15.8 <1.0 <1.0 38.1 0.484 3rd Qtr 9/11/2019 <1.0 15,8 <1.0 <1.0 39.7 0.412
4th Qtr 12/14/2019 <1.0 7.4 <1.0 <1.0 45.7 6.244 1st Qtr 3/17/2020 <1.0 6.93 <1.0 <1.0 43.2 0.222
2nd Qtr 6/11/2020 <1.0 4.9 <1.0 <1.0 42.4 ,0.205 3rd Qtr 9/18/2020 <1.0 3.6 <1.0 <1.0 40.5 0.144 4th Qtr 11/4/2020 <1.0 4.61 <1 0 <1.0 42.9 0.197
(1) VOCs were resarnpled because laboratory trussed holding time.
(2) Results of the TW4-70 the duplicate sample for TW4-6. (3) Reanalyzed for VOCs only. 1!) As of Man, 2„,2 oorh north and south wild life ends no lionler receivinuater.
Chloroform Eimpinjwell TW4-4 stared in 1st qtr 2010
Chloroform Eirnpirtwell 1W4-41 installed foiy 2018
NA and eN/A(for graphs). not analyzed
Shaded indicates concentrations exceeding GWQS.
TABLE 1 (10 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020 Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-7 Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride (5 pg/L) Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite (10 mg/L)
1st Qtr 3/16/2005 NA 3,100 NA NA NA 5.2
2nd Qtr 5/25/2005 NA 2,700 NA NA NA 5.4 3rd Qtr 8/31/2005 <10 3,100 <10 <10 NA 5.2
41h Qtr 12/7/2005 <50 2,600 <50 <50 52 5.3 .......... 1st Qtr 3/9/2006 <50 1,900 <50 <50 48 1
2nd Qtr 6/14/2606 ,..50 2,200 <50 <50 47 4.5
3rd Qtr 7/20/2006 <50 2,140 <50 <50 51 4.7
4th Qtr 11/8/2006 1.5 2,150 <1.0 <1.0 49 At 1st Qtr 2/28/2007 1.1 1,850 <1.0 <1.0 47 6 2nd )Qtr 6/27/2007 1.5 2,600 <1.0 <1.0 45 . 0,1 3rd Qtr 8/15/2007 1.4 2,300 <1.0 ) <1.0 44 4.1 4th Qtr 10/10/2007 1.2 .1,900 <1.0 <1.0 45 4.7
151 Qtr 3/28/2008 1.3 2,2-00 <1.0 <1.0 43 4.2 2nd Qtr 6/25/2008 1.3 1,800 <1.0 <1.0 43 4.8
3rd Qtr 9/10/2008 1.4 1,600 <1.0 <1.0 35 4.16
4th Qtr 10/15/2008 NA N/A NA NA 40 4.01
11/18/2008 <2.0 2.,00 <2.0 <2.0 NA #N/A
151 Qtr 3/11/2009 ) ) )1.2 1,800 <1.0 <1.0 35 3.7 2nd Qtr 6/23/2009 <1.0 1,400 <1.0 <1.0 37 3.8
3rd Qtr 9/14/2009 1 1,500 <1.0 <1.0 37 4.1 4th Qtr 12/29/2009 <1.0 1,300 <1.0 <1.0 37 4.2
1st Qtr 2/25/2010 <1.0 1,200 <1.0 <1.0 35 3.8 2nd Qtr 6/14/2010 <1.0 1,100 <1.0 <1.0 31 3.9
3rd Qtr 8/11/2010 1 1,500 <1.0 <1.0 .56. 3.9
4th Qtr 10/15/2010 <1.0 1100 <1.0 <1.0 381 4
1st Qtr 2/23/2011 <1.0 1,360 <1.0 <1.0 45 3.6
2ncl Qtr 6/1/2011 <1.0 1,200 <1.0 <1.0 35 4.0
3r4 atr 8/18/2011 <1.0 1,200 <1.0 <1.0 37 4.1
4th Qtr 11/29/2011 <1.0 1,660 <1.0 <1.0 37 3.8 1st Qtr (1 ) 1/19/2012 <1.0 ...1 boo <1.0 <1.0 37 3.9
2nd Qtr 6/14/2012 <1.0 . . 790 <1.0 <1,0 41 4.0 3rd Qtr 9/13/2012 <1.0 870 <1.0 <1.0 40 3.8
415 Qtr 10/4/2012 <1.0 940 <1.0 <1.0 41 3.8
1st Qtr 2/13/2013 ,<1.0, 940 <1.0 <1.0 37.7 3.51
2nd Qtr 6/18/2013 <i.o, 953 <1.0 <1.0 39.3 4
3rd Qtr 9/12/2013 <1.0 1,040 <1.0 <1.0 36.4 4 17
4th Qtr 11/14/2013 <1.0 , .1950 <1.0 <1.0 37.2 4 13
1st Qtr 2/5/2014 5.41 946 <1.0 <1.0 38.2 4.24
2nd Qtr 5/22/2014 4.78 847 <1.0 <1.0 37.7 4.19
3rd Qtr 8/27/2014 <1.0 557 1:5 <1.0 39 2.9 4th Qtr 10/30/2014 <1.0 926 <1.0 <1.0 40.2 3.68
1st Qtr (2) 3/18/2015 <1.0 942 <1.0 <1.0 40.4 4.25
2nd Qtr 6/11/2015 ) <1.0 956 <1.0 <1.0 42.1 2 62
3rd Qtr 9/10/2015 <1.0 897 <1.0 <1.0 46.7 4 72
4th Qtr 10/29/2015 <1.0 847 <1.0 <1.0 40.6 3.49
1st Qtr 3/22/2016 <1.0 834 <1.0 <1.0 42.4 4.43
2nd Qtr 6/8/2016 <1.0 909 <1.0 <1.0 44.1 3.75
3rd Qtr 8/4/2016 rn 1 0001:1 111=11111111111.M1 42.3 4.21
4th Qtr 10/26/2016 <1.0 886 <1.0 <1.0 45.8 ............ 4.33
1st Qtr 3/21/2017 <1.0 986 <1.0 <1.0 40.5 3.87
2nd Qtr 6/21/2017 <1.0 968 <1.0 <1.0 43.3 4.15
3rd Qtr 8/4/2017 <1.0 1,070 <1.0 <1.0 44.7 4.20
4th Qtr 10/11/2017 <1.0 884 <1.0 <1.0 43.7 4.35
DWMRC spht sample <7.6 890 <12 17 J 42.0 4.30
1st Qtr 3/21/2018 . . <1.0 721 <1.0 <1.0 44.5 3.96
2nd Qtr 6/14/2018 <1.0 751 <1.0 <1.0 41.5 4.45
3rd Qtr 9/6/2018 <1.0 781 <1.0 <1.0 48.5 4.34
41h Qtr 12/13/2018 <1.0 858 <1.0 <1.0 42.8 3.98
151 Qtr 3/20/2019 <1.0 736 <1.0 <1.0 41.3 4.01
2nd Qtr 6/19/2019 <1.0 862 <1.0 <1.0 43.0 4.19
3rd Qtr 9/12/2019 <1.0 301 <1.0 <1.0 39.6 3.76
41h Qtr 12/18/2019 <1.0 546 <1.0 <1.0 47.2 3.11 1st Qtr 3/18/2020 <1.0 746 <1.0 <1.0 42.1 3.75
2nd Qtr 6/12/2020 <1.0 1354 <1.0 <1.0 44.1 4.06 Dephcate TW4-75 <1.0 871 <1.0 <1.0 43.1 4.19
3rd Qtr 9/19/2020 <1.0 971 <1.0 <1.0 41.5 3.87 4th Qtr 11/11/2020 <1.0 967 <1.0 <1.0 42.8 4.40 DWMRC split sample <10 930 <20 <20 43 3.90
(1) As of Marc, 2012 toth myth and south v,;d liro pons e ce[
2) chloroform purnpinuells TW4-1 and TW4-2 started n 1/14/15 NA and #N/AloTgrails) = not analyzZ Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWOS. J = Approximated value
TABLE 1 (11 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-8
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA 10 NA NA NA <0.1
2nd Qtr 5/25/2005 NA <1.0 NA NA NA 0.2
3rd Qtr 8/31/2005 <1.0 1.1 1.7 NA NA <1.0
415 Qtr 12/7/2005 <1.0 <1.0 <1.0 <1.0 41 <1.0
1st Qtr 3/9/2006 <1.0 1.3 2.1 <1.0 39 0.3
2nd Qtr 6/14/2006 <1.0 1.8 1.0 <1.0 37 <1.0
3rd Qtr 7/20/2006 <1.0 <1.0 <1.0 <1.0 39 0.1
41h Qtr 11/8/2006 <1.0 <1.0 <1.0 <1.0 40 <.1
1st Qtr 2/28/2007 <1.0 2.5 <1.0 <1.0 39 0.7
2nd Qtr 6/27/2007 <1.0 2.5 <1.0 <1.0 42 0.2
3rd Qtr 8/15/2007 <1.0 1.5 <1.0 <1.0 42 <1.0
4th Qtr 10/10/2007 <1.0 3.5 <1.0 <1.0 43 0.5
1st Qtr 3/28/2008 <1.0 <1.0 <1.0 <1.0 46 0.1
2nd Qtr 6/25/2008 <1.0 <1.0 <1.0 <1.0 45 <1.0
3rd Qtr 9/10/2008 <1.0 <1.0 <1.0 <1.0 39 <0,05
4th Qtr 10/15/2008 <1.0 <1.0 <1.0 <1.0 44 <0.05
1st Qtr 3/4/2009 <1.0 <1.0 <1.0 <1.0 42 <0.1
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 44 <0.1
3rd Qtr 9/14/2009 <1.0 <1.0 <1.0 <1.0 44 <0.1
4t6 Qtr 12/17/2009 <1.0 <1.0 <1.0 <1.0 51 <0.1
1st Qtr 2/24/2010 <1.0 <1.0 <1.0 <1.0 57 <0.1
2nd Qtr 6/14/2010 <1.0 <1.0 <1.0 <1.0 42 <0.1
3rd Qtr 8/18/2010 <1.0 <1.0 <1.0 <1.0 45 <0.1
4th Qtr 10/15/2010 <1.0 <1.0 <1.0 <1.0 46 0.1
1st Qtr 2/16/2011 <1.0 <1,0 <1.0 <1.0 52 <0.1
2nd Qtr 5/25/2011 <1.0 <1.0 <1.0 <1.0 45 0.1
3rd Qtr 8/16/2011 <1.0 <1.0 <1.0 <1.0 46 0.1
4th Qtr 11/16/2011 45 0.2
...(.1)...... ...12I.71.?.9.1.1..`.:14?........... Tif Ofr (3) 1/18/2012 <i.o
<1.0
<to
<1.0 <to <1.0 <1.0 NA 45
#N/A
0.3
2nd Qtr 5/13/2012 <1.0 , <1.0 <1.0 <1.0 44 0.2
3rd Qtr 8/29/2012 <1.0 <1.0 <1.0 <1.0 48 0.1
4t6 otr 10/3/2012 <1.0 <1.0 <1.0 <1.0 47 <0.1
1st Qtr 2/7/2013 <1.0 <1.0 «1.0 <1.0 46.6 0.41
2nd Qtr 5/30/2013 <1.0 <1.0 <1.0 <1.0 45.5 <0.1
3rd Qtr 9/5/2013 <1.0 <1.0 <1.0 <1.0 47.5 0.1
4t6 Qtr 11/7/2013 <1.0 <1.0 <1.0 <1.0 46 1 <0.1
1st Qtr 1/23/2014 <1.0 63.8 <1.0 <1.0 48.5 0.166
.._ „(2) 2/6/2014 _. <1.0 100 <1.0 <1.0 46.5 , 0.166
2nd Qtr 5/22/2014 <1.0 122 <1.0 <1.0 53 0.538
3rd Qtr 8/27/2014 <1.0 , 107 <1.0 <1.0 47 0,6
4th Oh' 10/29/2014 <1.0 191 <1.0 <1.0 46.7 0.914 •
1st Qtr (4) 3/12/2015 <1.0 ,961 <1.0 <1.0 49.6 2.3
2nd Qtr 6/11/2015 <1.0 981 <1.0 <1.0 53 1.88
3rd Qtr 9/10/2015 <1.0 747 <1.0 <1.0 59.6 1.96
41h Qtr 10/29/2015 <1.0 770 <1.0 <1.0 52 2 2
1st Qtr 3/17/2016 <1.0 634 <1.0 <1.0 54.2 2.48
2nd Qtr 6/8/2016 <1.0 595 <1.0 <1.0 58.7 2.14
3rd Qtr 8/4/2016 <1.0 522 <1.0 <1.0 56.9 2.10
4th Qtr 10/27/2016 <1.0 472 <1.0 <1.0 60.1 2.16
1st Qtr 3/21/2017 <1.0 359 <1.0 <1.0 57.4 ,2.06
2nd Qtr 6/21/2017 <1.0 256 <1.0 <1.0 58.8 1.97
3rd Qtr 8/4/2017 <1.0 223 <1.0 <1.0 61.2 1.64
41h Qtr 10/11/2017 <1.0 214 <1.0 <1.0 52.2 1.92
Deplicate TW4-75 <1.0 194 1.12 <1.0 56.2 1.71
DWAARC split sample <1.9 230 4.7 J <3.0 61 1.90
1st Qtr 3/21/2018 <1.0 220 <1.0 <1.0 60.8 1.36
Deplicate 1W4-75 <1.0 171 <1.0 <1.0 60.8 1.36
2nd Qtr 6/14/2018 <1.0 155 <1.0 <1.0 53.8 , 1.31
3rd Qtr 9/5/2018 <1.0 137 <1.0 <1.0 63.2 1.40
4th Qtr 12/13/2018 <1.0 93.8 <1.0 <1.0 53.1 1.35
1st Qtr 3/19/2019 <1.0 103 <1.0 <1.0 54.3 1.23
2nd Qtr 6/19/2019 <1.0 66 <1.0 <1.0 56.5 1.1
3rd Qtr 9/12/2019 <1.0 75.4 <1.0 <1.0 52 0.999
Dephcate TW4-75 <1.0 75.6 <1.0 <1.0 52.5 1.030
4th Qtr 12/18/2019 <1.0 84.4 <1.0 <1.0 60.1 1.21
1st Qtr 3/18/2020 <1.0 55.0 <1.0 <1.0 53.8 1;04
2n4 Qtr 6/12/2020 <1.0 53.8 <1.0 <1.0 56.9 1.06
3rd Qtr 9/18/2020 <1.0 39.5 <1.0 <1.0 52.6 0.894
4th Qtr 11/11/2020 <1.0 51.3 <1.0 <1.0 54.7 1.27
Deplicate TW4-70 <1.0 52.9 <1.0 <1.0 49.9 1.27
DVVMRC split sample <10 50.0 <20 <20 56 0.16 H
(1) VOCs were resarnpled because laboratory missed holding time.
(2) Resampled to verify chloroform concentration that was collected on 1/23/14. OM of March 201.- no lonler receiving water
1,Li) chloroform purrjrinu:eris TW4-1 ana started in 1/14/15
NA and #N/A(for graphs). not analyzed
Shaded indicates concentrations exceeding GWQS.
J = Approximated value
H = Sample was analyzed beyond holding times and may not be accureate concentration.
TABLE 1 (12 of 31) Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation DUSA White Mesa Mill
TW4-9
Sampling Event
Parameter
(GWQS) Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride No GWQS (mg/L) Nitrate, Nitrate + Nitrite (10 mg/L)
1st Qtr 3/16/2005 NA 3.8 NA NA NA 1.3
2nd Qtr 5/25/2005 NA 1.2 NA NA NA 1.3
3rd Qtr 8/31/2005 <1.0 <1.0 2.9 <1.0 NA 1.3
41h Qtr 12/7/2005 <1.0 <1.0 <1.0 <1.0 42 1.3
1st Qtr, 3/9/2006 <1.0 <1.0 2.6 <1.0 38 1.5
2n4 Qtr 6/14/2006 <1.0 19 2.7 <1.0 39 1.5
3rd Qtr 7/20/2006 <1.0 <1.0 <1.0 <1.0 41 0.9
41h Qtr 11/8/2006 <1.0 <1.0 <1.0 <1.0 44 0.7
1st Qtr 2/28/2007 <1.0 <1.0 <1.0 <1.0 44 0.6
2nd Qtr 6/27/2007 <1.0 21 <1.0 <1.0, 42 1.3
3rd Qtr 8/15/2007 <1.0 9.5 <1.0 <1.0 38 1.8
41h Qtr 10/10/2007 <1.0 8.7 <1.0 <1.0 40 2
1st Qtr 3/28/2008 <1.0 , 1.3 <1.0 <1.0 35 2.1
2nd Qtr 6/25/2008 <1.0 1 <1.0 <1.0 35 2.3
3rd Qtr 9/10/2008 <1.0 <1.0 , <1.0 <1.0 28 2.79
411r Qtr 10/15/2008 <1.0 <1.0 <1.0 <1.0 58 1.99
1st Qtr 3/4/2009 <1.0 <1.0 <1.0 <1.0 30 2.5
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 30 2.3
3rd Qtr <1.0 <1.0 <1.0 <1.0 30 , 2.5
4th Qtr 12/17/2009 <1.0 <1.0 <1.0 <1.0 37 1.7
1st Qtr 2/23/2010 <1.0 <1.0 <1.0 <1.0 47 1.4
2nd Qtr 6/14/2010 <1.0 <1.0 <1.0 <1.0 33 1.5
3rd Qtr 8/13/2010 <1.0 <1.0 <1.0 <1.0 40 1.2
4th Qtr 10/15/2010 <1.0 <1.0 <1.0 <1.0 34 .1.:8 1st Qtr 2J17/2011 <'LO <1.0 <1.0 <1.0 41 .1,3
2nd Qtr 5/25/2011 <1.0 <1.0 <1.0 <1.0 30 3.4
3rd Qtr 8/16/2011 <1.0 <1.0 <1.0, <1.0 21 4
4th Qtr 11/16/2011 NA NA NA NA 38 2.3

_AD 1217/2011

1st Qtr (2) 1/18/2012 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
<1.0
<1.0
NA 28 -111
2nd Qtr 5/31/2012 <1.0 <1.0 <1.0 <1.0 , , 23 4.0,
3rd Qtr 8/30/2012 <1.0 <1.0 <1.0 <1.0 22 3.9
41h Qtr 10/3/2012 <1.0 <1.0 <1.0 <1.0 21 ....:P. 1st Qtr 2/7/2013 <1.0 <1.0 <1.0 <1.0 20.6 ..4,46 2nd Qtr 5/30/2013 <1.0 <1.0 <1.0 <1.0 21.4 4.49
3rd Qtr 9/5/2013 <1.0 <1.0 , <1.0 <1.0 22.7 4.03
4th Qtr 11/7/2013 <1.0 <1.0 <1.0 <1.0 23.6 4.87
1st Qtr 1/29/2014 <1.0 <1 0 , . <1.0 <1.0 22 4.36
2nd Qtr 5/22/2014 <1.0 6.9 <1.0 <1.0 24 3.44
3rd Qtr 8/14/2014 <1.0 47 <1.0 <1.0 27 2.7
4t8 Qtr 10/29/2014 <1.0 101 <1.0 <1.0 25 4.29
1st Qtr 3/12/2015 , <1.0 53.5 <1.0 <1.0 29.5 . . 3.28 ,
2nd Qtr 6/11/2015 <1.0 35.1 <1.0 <1.0 35.3 1.83
3rd Qtr 9/3/2015 <1.0 48 <1.0 <1.0 39.3 1.44
4th Qtr 10/28/2015 <1.0 68.4 <1.0 <1.0 29.2 ..2.:8.9.„ 1st Qtr 3/17/2016 <1.0 74.3 <1.0 <1.0 33.6 .2.51
2nd Qtr 6/8/2016 <1.0 76.2 <1.0 <1.0 35.1 2.16
3r4 Qtr 8/3/2016 <1.0 76.8 <1.0 <1.0 33.6 2.11
41h Qtr 10/26/2016 <1.0 76.0 <1.0 <1.0 37.4 .1:2!.1.
1st Qtr 3/17/2017 <1.0 113 <1.0 <1.0 34.5 2.18
2nd Qtr 6/21/2017 <1.0 113 <1.0 <1.0 35.9 1.92
3rd Qtr 8/3/2017 <1.0 118 <1.0 <1.0 37 1.90
4th Qtr 10/11/2017 <1.0 132 <1.0 <1.0 32 2.18
DWMRC split sample <0.98 120 <1.5 1.6 J 35 2.20
1st Qtr 3/21/2018 <1.0 159 <1.0 <1.0 38.3 1.85
2nd Qtr 6/4/2018 <1.0 134 <1.0 <1.0 35.7 1.85
DeplIcate13V4-75 <1.0 132 <1.0 <1.0 35.2 1.91
3rd Qtr 9/5/2018 <1.0 94.2 <1.0 <1.0 43.4 1.04
Deplicate TW4-75 <1.0 92.4 <1.0 <1.0 42,7 1.11
4th Qtr 12/13/2018 <1.0 109 <1.0 <1.0 ....6.,3. ...IP. 1st Qtr, 3/19/2019 <1.0 86.4 <1.0 <1.0 38.9 1.09
2nd Qtr 6/19/2019 <1.0 63.1 <1.0 <1.0 38,3 0.785
3rd Qtr 9/11/2019 <1.0 66.0 <1.0 <1.0 35.2 0.904
4th Qtr 12/18/2019 <1.0 54.8 <1.0 <1.0 40.1 0.744
lst Qtr 3/18/2020 <1.0 48.9 <1.0 <1.0 37.7 0.855
2nd Qtr 6/12/2020 <1.0 55.1 <1.0 <1.0 39.5 0.990
Deplicate TW4-70 <1.0 56.4 <1.0 <1.0 39.6 1.010
3rd Qtr 9/18/2020 <1.0 45.0 <1.0 <1.0 ,36.7 0.07 4th Qtr 11/11/2020 <1.0 47.1 <1.0 <1.0 37.2 1,11
DVVMRC split sample <10 48.0 <20 <20 38 0.97 DVVMRC Duplicate sample <10 46.0 <20 <20 38 0.97 (TW4-81)
(1) VOCs were resarnpled because laboratory mrssed holding ime. 2) AG of March 2012 both north and south wild life Londs no lonler recerving.s.mater.
NA and #N/A(for graphs) - not analyzed Shaded indicates concentrations exceeding GWQS. J = Approximate value
TABLE 1 (13 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020 Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-10 Sampling Event Parameter (GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate . Nitrite (10 mg/L)
1st Qtr 3/16/2005 NA 140 NA NA NA 1.6
2nd Qtr 5/25/2005 , NA 62 NA NA NA 0.8 3rd Qtr 8/31/2005 <2.5 110 6.2 <2.5 NA 1.1
4t5 Qtr 12/7/2005 <2.5 306 <2.5 <2.5 52 3.3 1st Qtr 3/9/2006 <5.9, 190 <5.0 <5.0 50 2.4
2nd Qtr 6/14/2006 <5.0 300 <5.0 <5.0 54 3.5 3rd Qtr 7/20/2006 <5.0 504 <5.0 <5.0 61 6.8
4th Qtr 11/8/2006 <1.0 452 1.6 <1.0 58 5.7
1st Qtr 2/28/2007 <1.0 500 <1.0 <1.0 2 7.3
2nd Qtr 6/27/2007 <1.0 350 <1.0 <1.0 54 5.1
3rd Qtr 8/15/2007 <1.0 660 <1.0 <1.0 59 7._ .3 4th Qtr 10/10/2007 <1.0 470 <1.0 <1.0 59 6.7
1st Qtr 3/28/2008 <1.0 620 <1.0 <1.0 55 7.3
2nd Qtr 6/25/2008 <1.0 720 <1.0 <1.0 „ .58 9.9
3rd Qtr 9/10/2008 , <1.0 660 <1.0 <1.0 51 9.23 4th Qtr 10/15/2008 NA #N/A NA NA 61 10.5
11/18/2008 <2.0 1130 <2.0 <2.0 NA #N/A 1st Qtr 3/11/2009 <1.0 1,100 <1.0 <1.0 64 11.6
2nd Qtr 6/23/2009 , <1.0, 1,200 <1.0 <1.0 62 9.8 3rd Qtr 9/14/2009 <1.0 910 <1.0 <1.0 51 8.1 4th Qtr 12/22/2009 <1.0 300 <1.0 <1.0 51 3.8
1st Qtr 3/3/2010 <1.0 460 <1.0 <1.0 48 5.0
2nd Qtr 6/14/2010 <1.0 220 <1.0 <1.0 42 1.6
3rd Qtr 8/12/2010 <1.0 100 <1.0 <1.0 38 0.8 4th Qtr 10/15/2010 <1.0 1,100 <1.0 <1.0 52. _ ._ .1.,1.0
lst Qtr 2/23/2011 <1.0 620 <1.0 <1.0 32 9.0
2nd Qtr 6/14/2011 , <1.0 280 <1.0 <1.0 42 3.3
3rd Qtr 8/17/2011 <1.0 180 <1.0 , <1.0 41 1.9 4th Qtr 1/16/2011 <1.0 110 <1.0 <1.0 45 ........ 1.1 1st Qtr (1 ) 1/19/2012 <1.0 76 <1.0 <1.0 40 0.9
2nd Qtr 6/14/2012 <1.0 79 <1.0 , <1.0 46 0.8
3rd Qtr 9/12/2012 <1.0, 130 <1.0 44 , 1.0 4th Qtr 10/3/2012 <1.0 140 <1.0 <1.0 45 1.6
1st Qtr 2/13/2013 <1.0 154 <1.0 <1.0 49.1 1.2
2nd Qtr 6/13/2013 <1.0 486 <1.0 <1.0 51.5 5.6
3rd Qtr 9/12/2013 <1.0 1,126 <1.0 <1.0 67.9 13.0 4th Qtr 11/14/2013 <1.0 .1,80 <1.0 <1.0 70.9 16.0
1st Qtr 1/29/2014 5.16 1,260 <1.0 <1.0 73 16.8
2nd Qtr 5/23/2014 <1.0 1,110 <1.0 <1.0 77.3 ' „:13.9 3rd Qtr 8/27/2014 <1.0 1,060 1,5 , <1.0 74 9.8
4th Qtr 10/30/2014 <1.0 1,220 <1.0 <1.0 75.2 13.2
1st Qtr 3/18/2015 <1.0 1,210 <1.0 <1.0 78.6 15.0
2nd Q1r 6/11/2015 <1.0 1,240 <1.0 <1.0 75 11.4
3rd Qtr 9/10/2015 <1.0 1,280 <1.0 <1.0 89.5 14.0
4th Qtr 10/29/2015 <1 0 1 350 <1.0 <1 0 79 9 13.5 1st Qtr 3/22/2016 <1.0 1,430 <1.0 <1.0 84.1 17.3.
2nd Qtr 6/8/2016 <1.0 1,510 <1.0 <1.0 89.5 14.9
3rd Qtr 8/4/2016 <1.0 1,500 <1.0 <1.0 85.3 14 9
41h Qtr 10/26/2016 <1.0 290 ....... 1.,. <1 0 - <1.0 84.4 14.8
1st Qtr 3/21/2017 <1.0 1,260 <1.0 <1.0 74.6 13.0
25d Qtr 6/21/2017 <1.0 1,140 <1.0 <1.0 73.1 13.0
3rd Qtr 8/4/2017 <1.0 1,320 <1.0 <1.0 77 13.4
4th Qtr 10/11/2017 <1.0 1,150 <1.0 <1.0 70 12.9
DWMRC.A01.42.5,(t <9.5 mg° <15 16 J 76 13.0
1st Qtr 3/21/2018 <1.0 1,240 <1.0 <1,0 72.7 11.1
25d Qtr 6/14/2018 <1.0 . 914 . < 0 1 <1.6 64.5 11.2 3rd Qtr 9/6/2018 , <1.0 911 <1.0 <1.0 75.5 10.1
4th Qtr 12/13/2018 <1.0 Igo <1.0 <1.0 63.5 10.6
1st Qtr 3/20/2019 <1.0 869 <1.0 <1.0 59.3 9.34 2nd Qtr 6/19/2019 <1.0 799 <1.0 <1.0 58.7 8.86
3rd Qtr 9/12/2019 <1.0 734 <1.0 <1.0 55.8 7.79
41h Qtr 12/18/2019 <1.0 768 <1.0 <1.0 62 6.89
1st Qtr 3/18/2020 <1.0 <1.0 53.5 7.83
2nd Qtr 6/11/2020 <1.0 928 <1.0 <1.0 60.1 8.13
3rd Qtr 9/19/2020 <1.0 854 <1.0 <1.0 53.9 7.34
4th Qtr 11/11/2020 <1.0 903 <1.0 <1.0 58.6 8.69
(1)fas of March 2012 both noah
NA and #N/A(for graphs) = not analyzed Shaded indicates concentrations exceeding GWQS.
J = Approximate value
TABLE 1 (14 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
T1N4-11(chlorof ern pumping well started 1/14/15)
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate . Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA 4,400 NA NA NA 8.7
2nd Qtr 5/25/2005 NA 3,590 NA NA NA 10.3
3rd Qtr 8/31/2005 <10 4,400 <10 <10 NA 9.4
4th Qtr 12/7/2005 <100 4,400 <100 <100 58 9.4
1st Qtr 3/9/2006 <50 4,400 <50 <50 56 9.2
2nd Qtr 6/14/2006 <50 4,300 <50 <50 56 10.0
3rd Qtr 7/20/2006 <50 4,080 <50 <50 55 10.0
4th Qtr 11/8/2006 1.7 3 660 2.7 1.3 55 10.0
1st Qtr 2/28/2007 1.3 3,600 <1.0 1.6 54 10.1
2nd Qtr 6/27/2007 1.6 3,800 <1.0 <1.0 53 10.6
3rd Qtr 8/15/2007 1.7 4,500 <1.0 <1.0 53 10.2
4th Qtr 10/10/2007 1.6 1,400 <1.0 1.2 53 9.8
1st Qtr 3/28/2008 <1.0 340 <1.0 <1.0 63 7.7
2nd Qtr 6/25/2008 <1.0 640 <1.0 <1.0 46 7.3
3rd Qtr 9/10/2008 <1.0 900 <1.0 <1.0 42 7.9
4th Qtr 10/15/2008 NA #N/A NA NA 47 9.5
11/18/2008 <2.0 Ippo <2.0 <2.0 NA #N/A
1st Qtr 3/11/2009 <1.0 1,000 <1.0 <1.0 49 7.3
2nd Qtr 6/23/2009 <1.0 980 <1.0 <1.0 44 6.8
3rd Qtr 9/14/2009 <1.0 1,000 <1.0 <1.0 49 7.0
4th Qtr 12/22/2009 <1.0 860 <1.0 <1.0 46 6.6
1st Qtr 3/3/2010 <1.0 820 <1.0 <1.0 42 6.8
2nd Qtr 6/14/2010 <1.0 820 <1.0 <1.0 40 6.9
3rd Qtr 8/12/2010 <1.0 800 <1.0 <1.0 43 6.7
4t6 Qtr 10/15/2010 <1.0 720 <1.0 <1.0 49 6.4
1st Qtr 2/23/2011 <1.0 1,000 <1.0 <1.0 46 6.
2nd Qtr 6/1/2011 <1.0 930 <1.0 <1.0 49 7.3
3rd Qtr 8/17/2011 <1.0 820 <1.0 <1.0 48 7.1
4th Qtr. 11/16/2011 <1.0 1500 <1.0 <1.0 46 7.1 1srOir (1) • 1/24/2012 <1.0 610 <1.0 <1.0 43 6.8
2nd Qtr 6/13/2012 <1.0 660 <1.0 <1.0 52 6.7
3rd Qtr 9/13/2012 <1.0 740 <1.0 <1.0 49 3.0
4t11 Qtr 10/3/2012 <1.0 730 <1.0 <1.0 so 7.0
1st Qtr 2/13/2013 3.23 867 <1.0 <1.0 47.3 6.8
2nd Qtr 6/18/2013 <1.0 788 <1.0 <1.0 49.3 7.4
3rd Qtr 9/12/2013 <1.0 865 <1.0 <1.0 46.6 7.8
41h Qtr 11/13/2013 <1.0 874 <1.0 <1.0 46.7 8.01
1st Qtr 2/5/2014 5.19 785 <1.0 <1.0 48.5 8.47
2nd Qtr 5/23/2014 <1.0 751 <1.0 <1.0 51.6 6.92
3rd Qtr 8/27/2014 <1.0 719 1.2 <1.0 48 5.4
4th Qtr 10/29/2014 <1.0 ' 803 <1 0 <1 0 56.4 7.33
1st Qtr(2) 3/9/2015 1.24 2,450 <1.0 <1.0 49.8 8.72
2nd Qtr 6/11/2015 <1.0 2,710 <1.0 <1.0 62.2 8.48
3rd Qtr 8/31/2015 <1.0 1,120 <1.0 <1.0 73.1 9.61
4th Qtr 10/29/2015 <1.0 2 730 <1.0 <1.0 55.3 7.5
1 st Qtr • 3/9/2016 1.2 2,660 <1.0 <1.0 55.5 7.13
2nd Qtr 5/23/2016 2.19 3,340 <1.0 <1.0 56.4 7.81
3rd Qtr 7/25/2016 <1.0 3,200 <1.0 <1.0 55.3 8.83
4th Qtr 10/12/2016 <1.0 3,200 <1.0 <1.0 57.2 8.92
1st Qtr 3/8/2017 1.71 3,310 <1.0 <1.0 49.8 8.12
2nd Qtr 6/13/2017 1.83 3,370 <1.0 <1.0 51.4 7.92
3rd Qtr 7/26/2017 1.81 3 290 , <1.0 <1.0 51 7.78
41h Qtr 10/11/2017 1.48 2,880 <1.0 <1.0 49.7 7.79
D1A/MRG_Hul!tssrdpie <38 2 900 <60 140 . 52 8 1st Qtr 3/12/2018 1.82 3,090 <1.0 <1.0 54 7.88
2nd Qtr 6/8/2018 1.34 2,800 <1.0 <1.0 52.4 7,51
3rd Qtr 8/22/2018 1.47 3,050 <1.0 <1.0 53.3 7.15
4t5 Qtr 11/28/2018 1.33 2.,930 <1.0 <1.0 45.4 6.85
1st Qtr 3/8/2019 1.48 2,820 <1.0 <1.0 46.8 7.50
2nd Qtr 6/5/2019 1.52 2,970 1.4 <1.0 45.3 8.30
3rd Qtr 9/4/2019 1.47 2,790 <1.0 <1.0 48.8 7.15
4th Qtr 12/18/2019 <1.0 3.250 <1.0 <1.0 49.0 7,,14
1st Qtr 2/19/2020 <1.0 2,990 <1.0 <1.0 51.9 7..0
2nd Qtr 5/11/2020 1.37 2,810 <1.0 <1.0 48.6 7.56
3rd Qtr 9/4/2020 1.47 3,070 <1.0 <1.0 46.3 7.59
4th Otr 10/28/2020 <1.0 2,670 3.86 <1.0 43.3 7.19
(1) As of March 2012 both north and south wild hte ponds no u0ger (ecesentt tt ate( 2) chloroform unwinLwell started 1/14/15. NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Bold and italics indicates the MDL exceeded the GWQS. = Approximated value
TABLE 1 (15 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Ciarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-12
Sampling Event
Parameter
(GWQS) Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (rng/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA <1.0 NA NA NA 1.4
2nd Qtr 5/25/2005 NA <1.0 NA NA NA 1.6
3rd Qtr 8/31/2005 <1.0 <1.0 5.8 <1.0 NA 1.5
4th Qtr 12/7/2005 <1.0 <1.0 1.0 <1.0 19 1.4
1st Qtr 3/9/2006 <1.0 <1.0 2.6 <1.0 19 1.3
2nd Qtr 6/14/2006 <1.0 <1.0 1.4 <1.0 16 1.4
3rd Qtr 7/20/2006 <1.0 <1.0 1.4 <1.0 16 1.4
4th Qtr 11/8/2006 <1.0 <1.0 <1.0 <1.0 16 ...1.4 lst Qtr 2/28/2007 <1.0 <1.0 <1.0 <1.0 16 1.5
2nd Qtr 6/27/2007 <1.0 <1.0 <1.0 <1.0 18 1.5
3rd Qtr 8/15/2007 <1.0 <1.0 <1.0 <1.0 29 1.4
4th Qtr 10/10/2007 <1.0 <1.0 <1.0 <1.0 16 1.4
1st Qtr 3/28/2008 <1.0 <1.0 <1.0 <1.0 16 1.6
2nd Qtr 6/25/2008 <1.0 <1.0 <1.0 <1.0 19 2.7
3rd Qtr 9/10/2008 <1.0 <1.0 <1.0 <1.0 18 2.7
4th Qtr 10/15/2068 <1.0 <1.0 <1.0 <1.0 22 2.5
1st Qtr 3/11/2009 <1.0 <1.0 <1.0 <1.0 23 2,4
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 22 3.8
3rd Qtr 9/14/2009 <1.0 <1,0 <1.0 <1.0 22 51. 4th Qtr 12/16/2009 <1.0 <1.0 <1.0 <1.0 23 3.6
lst Qtr 2/23/2010 <1.0 <1.0 <1.0 <1.0 22 4.0
2nd Qtr 6/14/2010 <1.0 <1.0 <1.0 <1.0 29 11.0. 3rd Qtr 8/10/2010 <1.0 <1.0 <1.0 <1.0 35 6.0
4th Qtr 10/15/2010 <1.0 <1.0 <1.0 <1.0 .31 8.0
1st Qtr 2/15/2011 <1.0 <1.0 <1.0 <1.0 31 6.6
2nd Qtr 5/25/2011 <1.0 <1.0 <1.0 <1.0 32 7.0
3rd Qtr 8/16/2011 <1.0 <1.0 <1.0 , , <1.0 31 ,6.8
41h Qtr 11/15/2011 <1.0 <1.0 <1.0 <1.0 30 8.0
1st Qtr (1 ) 1/17/2012 <1.0 <1.0 <1.0 <1.0 28 7.7
2nd Qtr 5/31/2012 <1.0 < to <1.0 <1.0 34 1076
3rd Qtr 8/29/2012 <1.0 <1.0 <i .0 <1.0 39 13.0
41h Qtr 10/3/2012 <1.0 <1.0 <1.0 <1.0 39 13.0
1st Qtr 2/13/2013 <1.0 <1.0 <1.0 <1.0 36.7 12.6
25d Qtr 5/29/2013 <1.0 <1.0 <1.0 <1.0 38.6 i 4.2
3rd Qtr 8/29/2013 <1.0 , <1.0 <1.0 <1.0 41.7 17.4
4th Qtr 11/6/2013 <1.0 <1.0 <1.0 <1.0 41.4 16.4
1st Qtr 1/22/2014 <1.0 <1.0 <1.0 <1.0 41.6 18.4
2nd Qtr 5/21/2014 <1.0 <1.0 <1.0 <1.0 40.2 17.0
3rd Qtr 8/27/2014 <1.0 <1.0 <1.0 <1.0 47 13.0
4th Qtr 10/23/2014 <1.0 <1.0 <1.0 <1.0 50.2 16„1.
1st Qtr 3/11/2015 <1.0 <1.0 <1.0 <1.0 50.6 19.
2nd Qtr 6/10/2015 <1.0 <1.0 <1.0 <1.0 56 18.8
3rd Qtr 9/2/2015 , <1.0 <1.0 <1.0 <1.0 60.2 16.4
4th Qtr 10/21/2015 <1.0 <1.0 <1.0 <1.0 51 18.0
Dephdate 'TW4-65 <1.0 <1.0 <1 0 _ 51.3 18.0
1st Qtr 3/15/2016 <1.0 <1.0 <1.0 <1.0 56.2 34.8
2nd otr 5/25/2016 <1.0 <1.0 <1.0 <1.0 66.4 30.7
Dank. iliVe-f 5/25/2016 <1.0 <1.0 <1.0 <1.0 67 113.0
3rd Qtr 7/27/2016 <1.0 <1.0 <1.0 <1.0 67.5 37.7
41h Qtr 10/12/2016 <1.0 <1.0 <1.0 <1.0 72.6 .2.5.:.8. 1st Qtr 3/14/2017 <1.0 <1.0 <1.0 <1.0 62.6 25.9
26d Qtr 6/14/2017 <1.0 1.25 <1.0 <1.0 67.2 29.9
3rd Qtr 8/2/2017 <1.0 1.2 <1.0 <1.0 65.3 25.1
Deplicate TW4-70 <1.0 1.19 <1.0 <1.0 67 26.7
4th Qtr 10/10/2017 <1.0 <1.0 <1.0 <1.0 56.2 26.9
Replicate TW4-70 <1.0 <1.0 <1.0 <1.0 61.4 26.8
1st Qtr 3/14/2018 <1.0 <1.0 <1.0 <1.0 59.5 19.8
2nd Qtr 6/12/2018 <1.0 ..„ <1.0 <1.0 <1.0 53,6 18.4
3rd Qtr 8/29/2018 <1.0 ,<1.0 <1.0 <1.0 59.9 13.6
415 Qtr 11/30/2018 <1.0 <1.0 <1.0 <1.0 56.1 10.4
1st Qtr 3/16/2019 <1.0 <1.0 <1.0 <1.0 50.8 10.1
2nd Qtr 6/13/2019 <1.0 <1.0 <1.0 <1.0 55.3 8.31
3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.6 52.6 8.88
4th Qtr 12/14/2019 <1.0 <1.0 <1.0 <1.0 §§,Cl. 8,04
1st Qtr 3/17/2020 <1.0 <1.0 <1.0 <1.0 sib 6.39
2nd Qtr 6/11/2020 <1.0 <1.0 <1.0 <1.0 51.7 4.95
3rd Qtr 9/17/2020 <1.0 <1.0 <1.0 <1.0 50.3 2.34
41h Qtr 11/4/2020 <1.0 <1.0 <1.0 <1.0 48.0 5.91
NA = not analyzed
Shaded indicates concentrations exceeding GWQS.
TABLE 1 (16 of 31) Historic Summary Of Monitoring Well Analytical Results Up To The 4th garter 2020
Chloroform Contamination Investigation DUSA White Mesa Mill
TW4-13
Sampling Event
Parameter (GWCIS)
Carbon Tetrachloride
(3 116/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 KIM
Chloride
No GWOS (mg/L)
Nitrate, Nitrate + Nitrite (10 mg/L)
1st Qtr 3/16/2005 NA <1 0 NA NA NA 4 2
2nd Qtr 5/25/2005 NA <1 0 NA NA NA 4 3
3rd Qtr 8/31/2005 <1 0 <1 0 3 1 <1 0 NA 4 6
4th Qtr 12/7/2005 <1 0 <1 0 . <1 0 .<1 0 69 4 3
1st Qtr 3/9/2006 <1 0 <1 0 1 7 <1 0 67 4 2
2nd Qtr 6/14/2006 <1 0 <1 0 1 4 <1 0 66 4 9
3rd Qtr 7/20/2006 <1 0 <1 0 <1 0 <1 0 65 4 3
4th Qtr 11/8/2006 <1 0 <1 0 <1 0 <1 0 33 0 8
1st Qtr 2/28/2007 <1 0 <1 0 <1 0 <1 0 59 4 0
2nd Qtr 6/27/2007 <1 0 <1 0 <1 0 <1 0 59 4 6
3rd Qtr 8/15/2007 <1 0 <1 0 <1 0 <1 0 58 4 4
41h Qtr .10/10/2007 0 .<1 <1 0 <1 0 <1 0 58 4 1
1st Qtr 3/28/2008 <1 0 <1 0 <1 0 <1 0 54 3 8
2nd Qtr 6/25/2008 <1 0 <1 0 <1 0 <1 0 58 4 2
3rd Qtr 9/10/2008 <1 0 <1 0 <1 0 <1 0 50 4 3
th Qtr 10/15/2008 <1 0 <1 0 <1 0 <1 0 58 4 6
15t Qtr 3/4/2009 <1 0 <1 0 <1 0 <1 0 58 3 7 nd Qtr 6/23/2009 <1 0 <1 0 <1 0 <1 0 57 1 2
3rd Qtr 9/14/2009 <1 0 <1 0 <1 0 <1 0 63 4 7
4th Qtr 12/16/2009 <1 0 <1 0 <1 0 <1 0 60 4 1
1st Qtr 2/24/2010 <1 0 <1 0 <1 0 <1 0 53 4 3
nd Qtr 6/14/2010 <1 0 <1 0 <1 0 <1 0 53 5 2
3rd Qtr 8/10/2010 <1 0 <1 0 <1 0 <1 0 55 5 6
41h Qtr 10/15/2010 <1 0 • <1 0 <1 0 <1 0 55. 5 8
1st Qtr 2/15/2011 <1 0 <1 0 <1 0 <1 0 60 5 5
2nd Qtr 5/25/2011 <1 0 <1 0 <1 0 <1 0 56 6 4
3rd Qtr 8/16/2011 <1 0 <1 0 <1 0 <1 0 60 5 2
4th Qtr 11/15/2011 <1 0 • <1 0 <1 0 <1 0 54 5 9 st Qtr (1) 1/17/2012 <1 0 <1 0 <1 0 <1 0 55 5 5
2nd Qtr 5/31/2012 <1 0 _ <1 0 <1 0 <1 0 59 6 0
3rd Qtr 8/29/2012 <1 0 <1 0 <1 0 <1 0 60 6 2
41h Qtr 10/3/2012 <1 0 <1 0 <1 0 <1 0 60 5 9
1st gtr 2/13/2013 <1 0 <1 0 <1 0 <1 0 59 3 6 31
2nd Qtr 5/29/2013 <1 0 <1 0 <1 0 <1 0 56 6 8
3rd Qtr 8/29/2013 <1 0 <1 0 <1 0 <1 0 63 5 7 16
4th Qtr 11/6/2013 <1 0 <1 0 <1 0 <1 0 58 5 6 48
1st Qtr 1/22/2014 <1 0 <1 0 <1 0 <1 0 63 1 7 09
2nd Qtr 5/21/2014 <1 0 <1 0 <1 0 <1 0 56 1 5 99
3rd Qtr 8/23/2014 <1 0 <1 0 <1 0 <1 0 62 4 8
4th Qtr 10/23/2014 0 ,<1 <1 0 <1 0 <1 0 66 1 6 28
1st Qtr 3/11/2015 <1 0 <1 0 <1 0 <1 0 66 4 7 09
2nd Qtr 6/10/2015 <1 0 <1 0 <1 0 <1 0 70 3 6 32
3rd Qtr 9/2/2015 <1 0 <1 0 <1 0 <1 0 76 5 5 7
4th Qtr 10/21/2015 <1 0 <1 0 <1 0 _........<1 0 ............ 65 5 _ 5 78
lst gtr 3/16/2016 <1 0 <1 0 <1 0 <1 0 69 4 7 97
2nd Qtr 5/25/2016 <1 0 <1 0 <1 0 <1 0 71 8 5 87
3rd Qtr 7/28/2016 <1 0 <1 0 <1 0 <1 0 69 3 6 14
41h Qtr 10/19/2016 <1 0 <1 0 <1 0 <1 0 70 9 6 20
1st Qtr 3/16/2017 <1 0 <1 0 <1 0 <1 0 66 0 6 05
2nd Qtr 6/15/2017 <1 0 <1 0 <1 0 <1 0 70 4 6 49
3rd Qtr 8/2/2017 <1 0 <1 0 <1 0 <1 0 70 5 6 15
4th Qtr 10/10/2017 0 .<1 <1 0 <1 0 <1 0 60 9 6 17
1st Qtr 3/14/2018 <1 0 <1 0 <1 0 <1 0 71 0 5 76
2nd Qtr 6/12/2018 <1 0 <1 0 <1 0 <1 0 65 0 6 24
3rd Qtr 8/29/2018 <1 0 <1 0 <1 0 <1 0 73 7 5 13
4th Qtr 11/30/2018 <1 0 . <1 0 <1 0 <1 0 64 5 5 29
1st Qtr 3/16/2019 <1 6 <1 0 <1 0 <1 0 61 6 5 74
2nd Qtr 6/13/2019 <1 0 <1 0 <1 0 <1 0 65 4 6 56
3rd Qtr 9/11/2019 <1 0 <1 0 <1 0 <1 0 65 3 5 19
41h Qtr 12/14/2019 <1 0 • <1 0 <1 0 <1 0 68 7 5 17
1st Qtr 3/17/2020 <1 0 <1 0 <1 0 <1 0 63 9 5 5
2nd Qtr 6/11/2020 <1 0 <1 0 <1 0 <1 0 62 7 9 0
3rd Qtr 9/17/2020 <1 0 <1 0 <1 0 <1 0 60 2 5 25 4th Qtr 11/4/2020 <1 0 <1 0 <1 0 <1 0 60 6 4 92
(1) As of March 2012 both north and south MC life ponds no lonier recewg water
NA = not analyzed Shaded indicates concentrations exceeding GWOS
TABLE 1 (17 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th garter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-14
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NS NS NS NS NS NS
2nd Qtr 5/25/2005 NS NS NS NS NS NS
3rd Qtr 8/31/2005 NS NS NS NS NS NS
4th Qtr 12/7/2005 NS NS NS NS NS NS
1st Qtr 3/9/2006 NS NS NS NS NS NS
2nd Qtr 6/14/2006 NS NS NS NS NS NS
3rd Qtr , 7/20/2006 NS NS NS NS NS NS
4th Qtr
lst Qtr
11th/2006
2/28/2007
<1.0
<1.0
NS <1.0 01.0
< .0
<1.0
<1.0 ...37 - '..6 ...ZA, 2.3
2nd Qtr 6/27/2007 <1.0 <1 0 , <1 0 <1.0 38 1.4
3rd Qtr 8/15/2007 <1.0 <1.0 <1.0 <1.0 36 1.1
4t6 Qtr 10/10/2007 <1.0 <1.0 <1.0 <1.0 38 0.8
1st Qtr 3/28/2008 <1.0 <1.0 <1.0 <1.0 57 0.4
25d Qtr 6/25/2008 <1.0 <1.5 <1.0 <1.0 35 1.6
3rd Qtr 9/10/2008 <1.0 <1.0 <1.0 <1.0 34 1.38
41h Qtr 10/15/2008 <1.0 <1.0 <1.0 <1.0 .40. ...0.:76
lst Qtr 3/4/2009 <1.0 <1.0 <1.0 <1.0 55 , 1,6
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 36 1.4
3rd Qtr 9/14/2009 <1.0 <1.0 <1.0 .0 38 1,
4th Qtr 12/16/2009 <1.0 <1.0 <1.0 <1.0 34 1.4
1st Qtr 3/23/2010 <1.0 <1.0 <1.0 <1.0 33 2.5
2nd Qtr 6/14/2010 <1.0 <1.0 <1.0 <1.0 49 2.9
3rd Qtr 8/10/2010 <1.0 <1.0 <1.0 <1.0 35 2.8
4th Qtr 10/15/2015 <1.0 <1.0 <1.0 <1.0 .2.9.. 2.9
lst Qtr 2/15/2011 <1.0 <1.0 <1.0 <1.0 25 1.8
2nd Qtr 6/24/2011 <1.0 <1.0 <1.0 <1 il) 24 1.4
3rd Qtr 8/16/2011 <1.0 <1.0 <1.0 <1.0 33 2.6
41h Qtr 11/15/2011 <1.0 <1.0 <1.0 1.0 15 1.7
1st Qtr (li 1/17/2012 <1.0 <1.0 <1.0 .0 20 1.9
2nd Qtr 6/14/2012 <1.0 <1.0 <1.0 <1.0 35 3.3
3rd Qtr 8/29/2012 <1.0 <1.0 <1.0 <1.0 37 3.9
4M Qtr 10/3/2012 <1.0 <1.0 <1.0 <1.0 37 3.9
1st Qtr 2/7/201,3 <1.0 <1.0 <1.0 <1.0 35.2 4.6
2nd Qtr 5/29/2015 <1.0 <1.0 , <1.0 <1.0 38.6 4.4
3rd Qtr 8/29/2013 <1.0 <1.0 <1.0 <1.0 37.6 4.81
4th Qtr 11/6/2013 <1.0 <1.0 <1.0 <1.0 36.5 4.81
1st Qtr 1/22/2014 <1.0 <1.0 <1.0 <1.0 35.5 5.92
2nd Qtr 5/21/2014 <1.0 <1.0 <1.0 <1.0 32.5 4.87
3rd Qtr 8/13/2014 <1.0 <1.0 <1.0 <1.0 38 4.1
41h Qtr 10/23/2014 <1.0 <1.0 <1.0 <1.0 38.9 5.22
1st Qtr 3/12/2015 <1.0 1.7 <1.0 <1.0 aol 5.22
2nd Qtr 6/10/2015 <1.0 1.82 <1.0 <1.0 41.8 3.55
3rd Qtr 9/3/2015 <1.0 <1.0 <1.0 <1.0 42.4 2.77
4th Qtr 10/23/2015 <1.0 1 46 <1 0 <1 0 40.6 2.45
let Qtr 3/16/2016 <1.0 4.49 <1.0 2.18 42.4 2.94
2nd Qtr 5/26/2016 <1.0 6.15 <1.0 3.18 43.6 2.45
3rd Qtr 8/3/2016 <1.0 5 <1.0 1.8 42.4 2.88
4th Qtr 10/20/2016 <1.0 7.02 <1.0 1.59 45.6 2.86
1st Qtr 3/15/2017 <1.0 6.45 <1.0 2.18 45.4 4.36
2nd Qtr 6/15/2017 <1.0 6.85 <1.0 <1.0 46.9 5.12
3rd Qtr 8/2/2017 <1.0, 6.14 <1.0 <1.0 46.4 4.84
4th Qtr 10/10/2017 <i.o 6.13 <1.0 <1.0 42.5 4.73
1st Qtr 3/15/2018 <1.0 5.8 <1.0 2 8 51.5 5.67
2nd Qtr 6/13/2018 <1.0 5.12 <1.0 <1(:), , 46.9 6.36
3rd Qtr 8/30/2018 <1.0 4.7e <1.0 <1.0 , 54.1 5.34
4th Qtr 12/12/2018 <1.0 4.41 <1.0 <1.5 48.7 5.85
1st Qtr 3/16/2019 <1.0 4.08 <1.0 <1.0 48.7 6.16
2nd, Qtr 6/13/2019 <1.0 4.18 <1.0 <1.0 48.3 5.86
3rd Qtr 9/11/2019 <1.0 6.08 <1.0 <1.0 45.4 , 4.77
4th Qtr 12/14/2019 <1.0 3.83 <1.0 <1.0 49.4 4.76
1st Qtr 3/17/2020 <1.0 2.98 <1.0 <1.0 48.4 6.17
2nd Qtr 6/11/2020 <1.0 2.87 <1.0 <1.0 47.6 6.57
3rd atr 9/18/2020 <1.0 2.41 <1.0 <1.0 45.1 5.57
41h Qtr 11/4/2020 <1.0 2.69 <1.0 <1.0 49.7 5.81
and south wild !le zonds no Muer recervrngoo
NS = not sampled
Shaded indlcates concentrations exceeding GAQS.
TABLE 1 (18 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-16
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 NA 240 NA NA NA <0 1 ,... „
2nd Qtr 5/25/2005 NA 212 NA NA NA <0.1
3rd Qtr 8/31/2005 <1.0 86 3.2 43 NA <0.1 ..
4th Qtr 12/7/2005 <1.0 .14 2.6 5.9 64 1.4
1st Qtr 3/9/2006 <1.0 39 1.1, 21 60 3
2nd Qtr 6/14/2006 <1.0 13 2.4 8.9 55 1.9
3rd Qtr 7/20/2006 <1.0 5.2 <1.0 2.7 60 2.7
4th Qtr 11/8/2002 <1.0 13.6 <1.0 9.2 62 5.6
1st Qtr 2/28/2007 <1.0 8.7 <1.0 6.6 79 12.3
2nd Qtr 6/27/2007 <1.0 2.6 <1.0 1.8 75 9.9
3rd Qtr 8/15/2007 <1.0 7.1 <1.0 5.1 65 5.4
4th Qtr 10/10/2007 <1.0 1.4 <1.0 1 69 4.4
1st Qtr 3/28/2008 <1.0 11 <1.0 26 52 <0.1,
2nd Qtr 6/25/2008 <1.0 •'1.0 <to <1.0 58 1.5
3rd Qtr 9/10/2008 <1.0 10 <1.0 14 71 10.5
41h Qtr 10/15/2008 <1.0 3.9 <1.0 6.6 89 9.8
1st Qtr 3/4/2009 <1.0 ,<1.0 <1.0 <1.0 73 9.6
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 76 „ 8.9
3rd Qtr 9/14/2009 <1.0 <1.0 <1.0 <1.0 79 8.8
4th Qtr 12/17/2009 <1.0 <1.0 <1.0 <1.0 76 5.2
1st Qtr 3/24/2010 <1.0 <1.0 <1.0 <1.0 77 4.2
2nd Qtr 6/14/2010 , , <1.0 2.1 <1.0 <1.0 64 4.7
3rd Qtr 8/24/2010 <1.0 4.3 <1.0 <1.0 72 4.6
4th Qtr 10/15/2010 <1.0 3 <1.0 <1.0 71 ..,..
1st Qtr 2/22/2011 <1.0 15 <1.0 <1.0 86 7
2nd Qtr 5/26/2011 <1.0 16 <1.0 <1.0 81 5
3rd Qtr 8/17/2011, <1.0 9.2 <1.0 <1.0 '63 1.7
4t5 Qtr 11/16/2011
(1) 12/7/2011
NA
<1.0
NA ,
<1.0 , NA
<1.0
NA
1.4 NA
38 0.4
1st Qtr (3) 1/18/2012 <1.0 <1.0 <1.0 1.7 48 0.1 _. ..
2nd Qtr 5/26/2012 <1.0, „ <1.0 <1.0 <1.0 53 <0.1
3rd Qtr 8/30/2012 <1.0 <1.0 <1.0 <1.0 59 <0.1
4th Qtr 10/3/2012 <1.0 <1.0 <1.0 <1.0 59 <0.1
1st Qtr 2/7/2013 <1.0 <1.0 <1.0 <1.0 58.1 <0.1
2nd Qtr 5/30/2013 <1.0 <1.0 <1.0 4.21 49.8 .0.1
3rd Qtr 9/5/2013 <1.0 <1.0 <1.0 <1.0 54.4 <0.1
4th Qtr 11/7/2013 <1.0 13.4 <1.0 <1.0 56.6 1,37
1st Qtr 1/29/2014 <1.0 6.93 <1.0 <1.0 66.8 3.16
2nd Qtr 5/22/2014 <1.0 14.6 <1.0 <1.0 80.7 4.94
3rd Qtr (2) 8/14/2014 <1.0 229 <1.0 <1.0 80 5.1
3rd Qtr 9/24/2014 <1.0 371 <1.0 <1.0 NA „ . NA
416 Qtr 10129/2014 <1.0 387 <1.0 <1.0 92.1 8.4
lst Qtr 3/12/2015 <1.0 153 <1.0 <1 0 „„.. 65 4.3
2nd Qtr 6/11/2015 <1.0 65.3 <1.0 <1.0 61 1.06
3rd Qtr 9/3/2015 <1.0 82 <1.0 <1.0 65.8 1.18
4th Qtr 10/28/2015 <1.0 112 <1.0 <1.0 58.3 1.69
1st Qtr 3/17/2016 <1.0 45.9 <1.0 <1.0 56.5 1.63
2nd Qtr 5/26/2016 <1.0 93.4 <1.0 <1.0 61.3 1.89
3rd Qtr 8/3/2016 <1.0 49 <1.0 <1.0 60 2.20
4t6 Qtr 10/26/2016 <1.0 92.9 <1.0 <1.0 66.7 2...7..8. l st Qtr 3/16/2017 <1.0 19.1 <1.0 <1.0 62.2 2.75
2nd Qtr 6/20/2017 <1.0 64.3 <1.0 <1.0 60.6 1.81
3rd Qtr 8/3/2017 <1.0 143 <1.0 , 67.1 2.63
4th Qtr 10/11/2017 <1.0 98 <1.0 <1.0 54.2 2.12
OWMRq.p)Y.W..)1,.!P <0,95 92 <1.5 1.9 J 64 2.00
1st Qtr 3/20/2018 <1.0 170 <1.0 <1.0 85.1 4.55
Duplicate TW4-75 <1.0 171 <1.0 <1.0 84.7 4.51
2nd Qtr 6/14/2018 <1.0 54.5 <1.0 <1.0 62.5 2.83
3rd Qtr 8/30/2018 <1.0 54.5 <1.0 <1.0 73 2.53
4th Qtr 12/12/2018 <1.0 52.0 <1.0 <1.0
1st Qtr 3/19/2019 <1.0 60.6 <1.0 <1.0 .66.3 3.36
2nd Qtr 6/19/2019 <1.0 76.2 <1.0 <1.0 „ 71.5 2.43
3rd Qtr 9/12/2019 <1.0 99.8 <1.0 <1.0 72.9 . . 3,55
4t6 Qtr 12/14/2019 <1.0 94.3 <1.0 <1.0 88.6 2.37
DdObate TW4-75 <1.0 91.0 <1.0 <1.0 84.1 3.12
1st Qtr 3/18/2020 <1.0 113 <1.0 <1.0 76.2 3.91
2nd Qtr 6/12/2020 <1.0 141 <1.0 , <1.0 79,7 4.44
3rd Qtr 9/19/2020 <1.0 220 <1.0 <1.0 77.4 4.74
41h Qtr 11/11/2020 <1.0 270 <1.0 <1.0 85.9 5.73
Duplicate TW4-75 <1.0 277 <1.0 <1.0 85.6 5.74
DWMRC split sample <10 290 <20 <20 87.0 0.37 H
(1) VOCs were resempled because laboratory missed holding ime.
(2) VOCs were resampled (3) As of March 2012 both north and south wild life ponds no longer receiving water.
NA = not analyzed Shaded indicates concentrations exceeding GWQS. J = Approximate value H = Sample was analyzed beyond holding times and may not be accureate concentration.
TABLE 1 (19 of 31) Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
I TW4-18
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform (70 pg/L) Chloromethane (30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr 3/16/2005 2nd Qtr 5/25/2005
3rd Qtr 8/31/2005 4th Qtr 12/7/2005
1st Qtr 3/9/2006
2nd Qtr 6/14/2006 3rd Qtr 7/20/2006
4th Qtr 11/8/2006 1st Qtr 2/28/2007
2nd Qtr 6/27/2007 3rd Qtr 8/15/2007
4th Qtr 10/10/2007 1st Qtr 3/28/2008
2nd Qtr 6/25/2008 3rd Qtr 9/10/2008
4th Qtr 10/15/2008 1st Qtr 3/4/2009
2nd Qtr 6/23/2009
3rid Qtr 9/14/2009 4th Qtr 12/17/2009
1st Qtr 3/24/2010 2nd Qtr 6/14/2010
3rd Qtr 8/12/2010 4th Qtr 10/15/2010
1st Qtr 2/22/2011 2nd Qtr 5/26/2011
3rd Qtr 8/17/2011
4th Qtr 11/16/2011
... It) 12/7/2011 4iftffr(2) 1/18/2012
2nd Qtr, 6/13/f011 3rd Qtr 9/11/2012
4th Qtr 10/3/2012
1st Qtr 2/13/2013 2nd Qtr 6/13/2013
3rd Qtr 9/5/2013 4th Qtr 11/13/2013
1st Qtr 1/30(2014 2nd Qtr 5/22/2014
3rd Qtr 8/14/2014 4th Qtr 10/28/2014
1st Qtr 3/12/2015 2nd Qtr 6/11/2015 3rd Qtr 9/3/2015
4th Qtr 10/28/2015 lstQtr 3/17/2016
2nd Qtr 6/8/2016 3rd Qtr 8/3/2016
4th Q(r 10/26/2016 1st Qtr 3/16/2017
Duplicate 1W4-75 2nd Qtr 6/20/2017
3rd Qtr 8/3/2017
Duplicate TW4-75 4th Qtr 10/11/2017
1st Qtr 3/15/2018 2nd Qtr 6/13/2018
3rd Qtr 8/30/2018
4th Qtr 12/13/2018
1st Qtr 3/19/2019
2nd Qtr 6/19/2019
Duplicate TW4-75 3rd Qtr 9/11/2019 4t6 Qtr 12/18/2019
1st Qtr 3/18/2020 2nd Qtr 6/12/2020
3rd Qtr 9/18/2020 4t5 Qtr 11/11/2020 DWMRC split sample
NA NA <1.0
<1.0 <1.0
<1.0 <1.0 , <1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0,
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
NA <1.0
<1.0
<1.0 -
<1.0 <1.0
<1.0 <1.0
<1.0 , <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 _ <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <10
NA
38
29.8 39
44
,

12
10.8 12.5
9.2 8
8.9 7.4
6.4 5.7
8 9.4
11 16 13
8.2 69
29 29
30 39
26 29
28
2Z
38 30 34.9
37.9 41
44.3 6.93
6.93 32.8
33
. . 32
30.5 28.7 52.9
56.6 60
56.3 60.1
62 61.5
63.8 62.8
62.3 62.9 62.3
59.9 56.2
57.6 52.8
54.2 54.4 56.2
62.0 57.0
58.2 60.0
58.6 56.0
25
NA
NA
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 NA
<1.0 <1.0
<1.0
<1.9 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1 0
<1.0 . . <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <20
2.8 1.1
1.6 2.7
NA
NA <1.0 <1.0
<1.0 <10
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 NA
<1.0 <1.0
<1 .0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0
<1.0

<1 0 _ <1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0

„ „. . <1.0 <1.0
<1.0 <1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0
<1.0 <1.0 <1.0 <20
1"4: NA
NA
NA
41
36 35 35
34 30
28 32
27 23
23 26
30 29
30 26 30
41 35
37 50
52 36 23
23
18
30 26 27
23.1 , 22.9
36.2 37.1
38.9 47
49
41.6 43.5 47.6

157.4i..
43.8 40 7 .. - 43.9 39.4
41.1 41.6,
40.4 41.5 37.1
44.3 39.5
45.6 38.2 37.6
39.5 , 40.8
36.8 42.7
, 39.4
, 41.4
38.7 „ 39.6 41.0
NA
141 12.9 13.3
7.3 5.9
4.7 6.1
5.7 5.1
, 4.9 5.0
4.4 0.7
4.6 4.9 5.2
5.2 6.2
5.9 5.4
5.1 9.0 9.0
10.0 ,10.0
9.0 4.6
6.3
4.4
6,6 6.6 6.0
5.6 8.9
12.1 14.2 12.8
12.2 9.8
11.1 ............ ........... 11.7
9.69 15.7
6.24 5.96 5.45
5.73 5.24
4.47 4.41
4.50 4.24
4.31 4.43
4.32 4.09 3.51
3.60 3.85 . „ 4.01 2.95
3.25 3.02
3.71 3.62 3.36
3.67 3.30
(1) VOCs were resembled because laboratory missed holding time. l2) As of March 2012 both north and south wild life ponds no longer receiving water.
NA = not analyzed Shaded indicates concentrations exceeding GWQS.
TABLE 1 (20 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-19 (chlorofrorn pumping well started 4/30/03) Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1st Qtr , 3/16/2005 NA 2,200 NA NA NA 5.3
2nd Qtr 5/25/2005 NA 1,200 NA NA NA 5.71
3rd Qtr 8/31/2005 <5.0 1,400 <5.0 <5,0 NA 4.6
4th Qtr 12/7/2005 <50 2800 <50 <50 81 <0.1 ....
1st Qtr 3/9/2006 <50 1,200 <50 <50 86 „ 4 2nd Qtr 6/14/2006 <50 1,100 <50 <50 116 5.2
3rd Qtr 7/20/2006 <50 1,120 <50 <50 123 4.3
4th Qtr 11/8/2006 1.6 1,050 2.6 <1.0 134 4.6
1st Qtr 2/28/2007 1.3 1,200 <1.0 , <1.0 133
2nd Qtr 6/27/2007 Did not sample
3rd Qtr 8/15/2007 1.9 1,100 <1.0 <1.0 129 4.1
4th Qtr 10/10/2007 1.9 1 100 <1 0 <1.0 132 4
1st Qtr 3/28/2008 2.9 1,8-60 <1.0 <1.0 131 2.2
2nd Qtr 6/25/2008 , <1.0 1,000 <1.0 <1.0 128 2.8
3rd Qtr 9/10/2008 8.6 3,600 <1.0 <1.0 113 35.2
41h Qtr 10/15/2006 12 4,20.0 <1.0 <1.0 124 47.8
1st Qtr 3/4/2009 1.2 1,100 <1.0 <1.0 127 3,2
2nd Qtr 6/23/2009 1.2 990 <1.0 <1.0 132 2.4
3rd Qtr 9/14/2009 15 6,600 <1.0 <1.0 43 <0.1
4t5 Qtr 12/22/2009 16 4,700 <1.0 <1.0 124 26.7
1st Qtr 2/17/2010 1.3 940 <1.0 <1.0 144 2
2nd Qtr 6/14/2010 4.2 1,800 <1.0 , <1.0 132 ,4,4
3rd Qtr 8/16/2010 4.9 , 2,000 <1.0 <1.0 142 5.9
41h Qtr 10/15/2010 1.3 1200 <to <1.0 146 2.7
1st Qtr 2/17/2011 17 3,400 <1.0 <1.0 135 17.0
2nd Qtr 6/7/2011 8.3 4,000 <1.0 , <1.0 148, 12.0
3rd Qtr 8/17/2011 2.1 970 <1.0 <1.0 148 3.0
4th Qtr 11/16/2011 148 5.0
...1.1.) 12/5/2011 5.4 2 200 <1 0 <1.0
1st WI' (2) 1/23/2012 1.5 650 <1.0 <1.0 138 0.6
2nd Qtr 6/6/2012 1.f 466 <1.0 <1.0 149 2.4
3rd Qtr 9/4/2012 3.5 950 <1..0 <1.0 149 2.5
4t5 Qtr 10/3/2012 4 1500 <1.0 <1.0 150 4.1
1st Qtr 2/13/2013 5.15 4,210-.0.0 <1.0 164 8.0
2nd Qtr 6/5/2013 5.15 2,070 <1.0 <1.0 148 3.0
3rd Qtr 9/3/2013 20.7 8,100 <1.0 <1.0 179 17.6
41h Qtr 10/29/2013 6.42 942 <1.0 <1.0 134 4.7
1st Qtr 1/27/2014 4.05 586 <1.0 <1.0 134 1.6
2nd Qtr 5/19/2014 5.51 810 <1.0 ..„ <1.0 152 1.3
3rd Qtr 8/11/2014 1.9 1,410 8.3 <1.0 140 1.6
4th Qtr 10/21/2014 4.8 .4,310 <1.0 <1.0 130 4.7
1st Qtr 3/9/2015 8.92 4,660 <1.0 <1.0 238 8.56
2nd Qtr 6/8/2015 2.62 1,570 <1.0 <1.0 180 0.916
3rd qtr 8/31/2015 <1.0 7,860 7.78 <1.0 326 11.6
4tk Qtr 10/19/2015 12.2 7 840 5.46 <1.0 252 10.6
1st Qtr 3/9/2016 13.5 7,780 1.4 <1.0 , 276 15.70
2nd Qtr 5/26/2016 23.1 12,600 <1.0 <1.0 204 1.27
3rd Qtr 7/25/2016 9.89 6 040 <1 0 <1.0 214 10.5
41h Qtr 10/13/2016 10.8 6,840 <1.0 <1.0 200 10.0
1st Qtr 3/8/2017 3.06 1,240 <1.0 <1.0 461 11.1
2nd Qtr 6/13/2017 1.35 510 <1.0 <1.0 135 0.243
3rd Qtr 7/26/2017 13.0 8,840 <1.0 <1.0 218 1.120
4th Qtr 10/11/2017 <1.0 129 <1.0 <1.0 139 0.377
1st Qtr 3/12/2018 1.36 • 2,640 „ <1.0 <1.0 193 8.6
2nd Qtr 6/8/2018 3.45 2,980 <1.0 <1.0 138 0.494
3rd Qtr 8/30/2018 2.03 1,910 <1.0 <1.0 166 2.55
4th Qtr 11/28/2018 6.18 .6.,27.0 <1.0 <1.0 140 0.233
1st Qtr 3/8/2019 2.43 2,050 <1.0 <1.0 197 6.58
2nd Qtr 6/5/2019 „ 15.9 11,500 <1.0 <1.0 160 8.96
3rd Qtr 9/4/2019 10.1 6,670 <1.0 <1.0 153 0.33
4th Qtr 12/10/2019 <1.0 551 <1.0 <1.0 147 0.535
1st Qtr 2/19/2020 13.7 8 720 5.41 <1.0 205 10.1
2nd Qtr 5/27/2020 10.4 7,600 <1 .0 <1.0 147 1.14
3rd Qtr 9/4/2020 1.98 1,350 <1.0 <1.0 lAct 11.6
4th Qtr 10/28/2020 1.1 660 <1.0 <1.0 104 1.1
(1) VOCs were resampled because laboratory missed holding time. (2) As of March 2012 both north and south wild life ponds no longer receiving water.
NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Shaded indicates concentrations exceeding GWQS.
TABLE 1 (21 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-20 (chloroforrn purnping well started 8/4/05) Sampling Event
_ Parameter
(GWQS)
Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate + Nitrite
(10 mg/L)
1s1 Qtr 3/16/2005 , Monitor well was not installed 2nd Off' (3) 5/25/2005 NA 39,000 NA NA ' ' NA 10.10
3r4 Qtr 8/31/2005 <10 3,806 <10 <10 NA ..„. 2.90
4th Qtr 12/7/2005 <250 19,000 <250 <250 131 1.80
1st Qtr 3/9/2006 <500 9,200 <500 <500 120 3.80
20d Qtr 6/14/2006 <500 , 61,000 <500 <500 235 9.40
3rd Qtr 7/20/2006 <1000 5,300 <1000 , , <1000 134 2.90
4t5 Qtr 11/8/2006 7.1 11 000 1.9 2.2 ..1.24 3.50
1st Qtr 2/28/2007 3.1 4,400 <1.0 1.1 124 . 4.20
2nd Qtr 6/27/2007 2.2 1,800 <1.0 <1.0 112 2.30
3rd Qtr 8/15/2007 3.5 5,200 <1.0 1.8 117 2.10
4th Qtr 10/10/2007 6.8 ,9.,000 <1.0 1.9 170 5.60
1st Qtr 3/28/2008 9 13,000 <1.0 1.5 ,132 0.90
25d Qtr 6/25/2008 1,3 30,000 <1.0 1.2 191 8.00
3rd Qtr 9/10/2008 15 . 21,000 <1.0 3.7 156 ,4.44
41h Qtr 10/15/2008 NA NA NA NA 168 5.51
1st Qtr 3/4/2009 5.7 8,200 <1.0 5.2 164 5.10
2nd Qtr 6/23/2009 4.9 6,800 <1.0 4.2 164 2.90
3rd Qtr 9/14/2009 8.4 13,000 <1.0 4.4 153 3.30
4th Qtr 12/22/2009 14 15,000 <to 3.0 187 5.30
1st Qtr 2/17/2010 2.7 3,500 <1.0 3.2 179 2.00
2nd Qtr 6/14/2010 11 18,000 <1.0 3.7 200 5.60
3rd Qtr 8/16/2010 12 15,000 <1.0 2.2 196 5.30
4t5 Qtr 10/15/2016 20 24,000 <1.0 5.5 203 4.60
1st Qtr 2/17/2011 27 31,000 <1.0 19.0 220 4.40
2nd Qtr 6/7/2011 10 8,100 <1.0 2.1 177 4-00:
3rd Qtr 8/17/2011 7.3 3,800 <1.0 3.1 207 6.50
4th Qtr 11/16/2011 7.2 7,900 <1.0 2.5 186 4.20
1st Qtr (2) 1/23/2012 10 11,000 <1.0 1.3 ._ 207 7.90
2nd Qtr 6/6/2012 33 36,000 <1.0 01.0 262 11.00
3rd Qtr 9/4/2012 26 13,000 <1.0 <1.0 289 10.80
41h Qtr 16/3/2012 22 19,000 <1.0 <1.0 302 11.00
1st Qtr 2/11/2013 19.6 18,500 <1.0 1.21 252 9.07
25d Qtr 6/5/2013 32.5 26,300 <1.0 1.3 250 9.80
3rd Qtr 9/3/2013 25.7 26,800 <1.0 2.14 260 8.65
4th Qtr 10/29/2013 17.3 15,700 <1.0 1.37 272 9.64
1st Qtr 1/27/2014 18.4 17800 <1.0 2.04 254 7.56
2nd Qtr 5/19/2014 _ , 22.1 22,100 2.31 3.98 269 5.95
3rd Qtr 8/11/2014 14.1 12,400 55,2 2.2 299 4.30
4th Qtr 10/21/2014 18.5 23 300 4.04 2.38 292 .......7.0. 1st Qtr 3/9/2015 20.8 19,900 4.85 1.38 296 946
2rid Qtr 6/8/2015 16.2 17,600 13.4 1.73 296 5.76
3rd Qtr 8/31/2015 15.1 17,000 12.3 <1.0 365 9.3
4th Qtr 10/19/2015 14.5 17 000 10 8 1 293 6.23
1st Qtr 3/9/2016 20.2 21,600 4 09 - 1.16 293 10.30
25d Qtr 5/23/2016 40.6 33,700 <1.0 <1.0 318 11.2
3rd Qtr 7/25/2016 26.6 23,600 <1.0 <1.0 307 11.3
411r Qtr 10/12/2016 24.4 21,300 <1.6 <1.0 361 11.4
1st Qtr 3/8/2017 23.5 2.3,460 <1,0 <1.0 290 12.0
2nd Qtr _8/13/2017 23.4 18,160 <i.o <1.0 281 9.76
3rd Qtr 7/26/2017 25.0 27,600 1.25 <1.0 , 292 10.8
4th Qtr 10/12/2017 11.2 1.1600 2.34 <1.0 .......2.. ....All lst Qtr 3/12/2018 15.9 15,400 1.77 2.36 289 9.
2nd Qtr 6/14/2018 <1.0 12,000 <1.0 7.77 258 10.40
3rd Qtr 8/22/2018 , _ , 9.85 10,500 4.98 <1.0 282 8.14
4th Qtr 11/28/2018 8.32 9,500 15.6 <1.0 295 9.72
1st Qtr 3/8/2019 15.4 15 600 , <1.0 <1.0 272 6.7
2nd Qtr 6/5/2019 10.1 13,706 <1.0 <1.0 279 9.59
3rd Qtr 9/4/2019 8.39 16,500 <1.0 <1.0 286 10.20
4th Qtr 12/10/2019 5.92 82.0 2.67 <1.0 307 9.75
1st Qtr 2/19/2020 8.6 14,300 10.7 .... <1.0 310 9.81
2nd Qtr 5/27/2020 6.74 5,800 1.3 12.3 3.01 7.23
Well TW4-20 Abandoned in October 2020
(1) VOCs were resampled because laboratory missed holding time. (2) As of March 2012 both north and south wild life ponds no longer receiving water.
2) Chloroform EiJrn p in Ewell started 8/4/05.
NA = not analyzed
Bold and italics indicates the MDL exceeded the GWQS. Shaded indicates concentrations exceeding GWQS.
TABLE 1 (22 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-21 (chloroform pumping well 6/9/15)
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate . Nitrite
(10 mg/L)
151 Qtr 3/16/2005
2nd otr 5/25/2005
3rd Qtr 8/31/2005
4th Qtr 12/7/2005
1st Qtr 3/9/2006 , . , 2nd Qtr 6/14/2006
3rd Qtr 7/20/2006
41h Qtr 11/8/2006
1st Qtr 2/28/2007
2nd Qtr 6/27/2007
3rd Qtr 8/15/2007
41h Qtr 10/10/2007
1st Qtr 3/28/2008
2nd Qtr 6/25/2008
3rd Qtr 9/10/2008
4th Qtr 10/15/2008
11/18/2008
1st Qtr 3/11/2009
2nd Qtr 6/23/2009
3rd Qtr 9/14/2009
4th Qtr 12/22/2009
let Qtr 2/25/2010
2nd Qtr 6/14/2010
3rd Qtr 8/13/2010
4th Qtr 10/15/2010
1st Qtr 2/22/2011
2nd Qtr 6/28/2011
3rd Qtr 8/17/2011
4th Qtr 11/16/2011

All 12/7/2011 Tif tilt- (2) 1/23/2012
2nd Qtr 6/6/2012
3rd Qtr 9/4/2012
41h Qtr 10/3/2012
1st Qtr 2/11/2013
2nd Qtr , 6/5/2013
3rd Qtr 9/3/2013
4t9 Qtr 10/29/2013
1st Qtr , 1/27/2014
2nd Qtr , 5/19/2014
3rd Qtr 8/11/2014
4th Qtr 10/21/2014
1st Qtr 3/9/2015 2nd Qtr (3) 6/8/2015
3rd Qtr 8/31/2015
4th Qtr 10/19/2015
1st Qtr 3/9/2016
2nd Qtr 5/23/2016
3rd Qtr 7/25/2016
41h Qtr 10/12/2016
1st Qtr 3/8/2017
2nd Qtr 6/13/2017
3rd Qtr 7/26/2017
4th Qtr 10/11/2017
DWMRQA0( ssfyipis
1st Qtr 3/12/2018
2nd Qtr 6/8/2018 3rd Qtr 8/22/2018
4th Qtr 10/22/2018 1st Qtr 3/8/2019
2nd Qtr 6/5/2019
3rd Qtr 9/4/2019
41 tsht QQ tt rr 12/10/2019
2/19/2020
2nd Qtr 5/27/2020
3rd Qtr 9/4/2020 41h Qtr 10/28/2020
NA
<5.0
<1.0
<2.5 , <2.5
<2.5
<1.0
<1.0
NA
,<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
..„„ 2 1.8
e.8
7
1.7
1.6
2
9.2
1 2
1.2 , 4.8
6.3
- .._.
#N/A
160
366
339
596
192
78
86
120
120 108
139 160
300
140
120
390
180
120
170
180
200 200
170
210
390
200
230
290
460
390
420
400
410
390
282
328
244
204
220
240
204
229
292
28r
395
545
456
456
598
224
537
466
400
421
532
476 585
323 734
794 844
767
920
948
NA
<SO
<1.0
<2.5
<2.5
<2.5
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<to
<1.0
NA
<2.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1 0 . <1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.6
<1.0
<1.0
<1.0
<6.0
<1.0
<1.0
<1.0 <1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
. <1.0
Monitor
, .
2.58
well was not installed
NA <5.0
<1.0
<2.5
<2.5 <2.5
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0. <1.0
NA
<2.0
<1.0
<1.0
<1.0 <1.0
<1.0 <1.0
<1.0
<1.0 _ <1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0 <1.0
<1.0
<1.0
<1.0
2.04
2.94,
<1.0
<1.0
<1.0 <1.0
<1.0
<1 0 - <1. 0 ___
<1.0
<1.0
<1.0
<1.0
<1.0
<1,0 <1.0
14 J
<1.0
<1.0
<1.0 <1.0
<1.0 <1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<1.0
NA
NA
NA
_
_
353
347
318
357 296
306 327
300
288
331
271
244
284
279
291
281 256
228 . 266
278
303
290 287
287
285 142
......279. 221
, 243
207
206
200
243
230
252
255
499 413
425
457
439
452
309
447
378 310
447
387
182
392 180
456 478
339
446
353 382 411
210
#N/A
14.6
16.1 9.6
8.5 10.2
8.9
8.7
8.7
8.6 8.6
8.3
14.3
8.8
7.57
8.0
8.3
8.1
9.2
8.4 8.4
12.0
14,0: 7.0
9.0
12.0
14.0
13.0
6.7 6.4
5.4
6 7
5.25
228 15.0
11.0
13.0
14:0. 11.6 13.8
10.3
<1.0
3.49
2.13 9.0,
11.41
11.51
7.1 <1.0
<1.0
<1.0
<1.0
<1.0 <1.0
<1.0
<1.0
<3.8
<1.0 <1.0
<1.0 <1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0 <1.0
6.23
4.73
1.04
1.75
1.92
2.36
1.16
1.05
2.36
494
10.0
10.9
13.1
14.7
14.3
'.1.3.,1. 16.5
13.5
17.7
9.53
16.20
16.90
11
15.8
14.1
0.236
15.2 8.99
17.5
14,7 5.73
8.93
15.4
12.6 16.3
(1) VOCs were resampled because laboratory missed holding time. (2) As ot March 2012 both north and south wild lite ponds no longer rec ing water.
2)-ogroToir)Mn pumping well start-WM/TS.
NA =7)oTa-r-talySed Shaded indicates concentrations exceeding GWQS. J = Approximated value
TABLE 1 (23 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020 Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-22 (nitrate pumping well started 1/26/13)
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chlonde
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate -i- Nitrite
(10 mg/L)
1s1 Qtr 3/16/2005 Monitor well was riot installed
2nd Qtr 5/25/2005 NA 340 NA NA NA 18.2
3rd Qtr 8/31/2005 <5.0 290 <5.0 <5.0 NA 15.7
41h Qtr 12/7/2005 <5.0 320 <5.0 <5.0 253 15.1
15t Qtr 3/9/2006 <10 390 <10 <10 236 15.3
2nd Qtr 6/14/2006 <10 280 <10 <10 221 14.3
3rd Qtr 7/20/2006 <10 864 <10 <10 221 14.5
41h Qtr 11/8/2006 <1.0 350 1.6 <1.0 236 15.9
lst Qtr 2/28/2007 <1.0 440 <1.0 <1.0 347 20.9
2nd Qtr 6/27/2007 <1.0 740 <1.0 <1.0 273 19.3
3rd Qtr 8/15/2007 <1.0 530 <1.0 <1.0 259 19.3
4th Qtr 10/10/2007 <1.0 440 <1.0 <1.0 238 18.8
1st Qtr 3/28/2008 <1.0 1,400 <1 0 <1.0 519 39.1
2nd Qtr 6/25/2008 <1.0 1,200 <1.0 <1.0 271 41.9
3rd Qtr 9/10/2008 1.3 6,300 <1.0 <1.0 524 38.7
41h Qtr 10/15/2008 NA 0N/A NA NA 539 36.3
11/18/2008 <2.0 630 <2.0 <2.0 NA #N/A
1st Qtr 3/11/2009 <1 0 390 <1 0 <1.0 177 20.7
2nd Qtr 6/23/2009 <1.0 730 <1.0 <1.0 177 20.6
3rd Qtr 9/14/2009 <1.0 2,300 <1.0 <1.0 391 40.3
41h Qtr 12/29/2009 <1.0 380 <1.0 <1.0 175 17.8
1st Qtr 3/23/2010 <1.0 2,200 <1.0 <1.0 427 36.8
2nd Qtr 6/14/2010 <1.0 540 <1.0 <1.0 134 19.0
3rd Qtr 8/24/2010 <1.0 340 <1.0 <1.0 130 15.0
4th Qtr 10/15/2010 1st Qtr 2/22/2011 <1.0 1.2
340
1,300
<1.0
<1.0
<1.0
<1.0
134
114 ' ---141
2nd Qtr 6/1/2011 <1.0 210 <1.0 <1.0 138 17.0
3rd Qtr 8/17/2011 <1.0 450 <1.0 <1.0 120 15.0
41h Qtr 11/16/2011 NA 0N/A NA NA 174 19.0
...(.I) 12/7/2011 , <1.0 400 <1.0 <1.0 NA 0N/A
1st Qir (2) 1/19/2012 <1.0 200 <1.0 <1.0 36 14.0
2nd Qtr 6/13/2012 <1.0 120 <1.0 35 12.8
3rd Qtr 9/12/2012 <1.0 121 <1.0
1<1.0
<1.0 7.0
41h Qtr 10/4/2012 <1.0 330 <1.0 <1.0 130 14.0
1st Qtr (3) 2/11/2013 3.24 10,600 <1.0 <1.0 130 58.0
2nd Qtr 6/5/2013 3.35 12,500 <1.0 <1.0 586 50.2
3rd Qtr 9/3/2013 3.25 9,640 <1.0 <1.0 487 29.7
4,r1..g.f............. .1.N911QP,........ 8.09 13,300 <1.0 <1.0 501 .....4.5.: 1st Qtr 1(27/2014 6.06 12,100 <1.0 2.83 598 54.6
2nd Qtr 5/19/2014 6.65 12,400 <1.0 <1.0 614 47.2
3rd Qtr 8/11/2014 1.9 12,400 40 <1.0 540 41.5
4th Qtr 10/29/2014 3.32 12,,400 1.61 <1.0 596 54.9
1st Qtr 3/9/2015 3.77 12,700 4.31 <1.0 675 69.2
2n4 Qtr 6/8/2015 2.42 8,050 3.42 <1.0 390 47.1
3rd Qtr 8/31/2015 <1.0 7,810 5.47 <1.0 557 64.7
415 Qtr 10/19/2015 3.32 7 530 ...,_ 5 1 <1 0 567 56 1
1st Qtr 3/9/2016 <1.0 6,070 <1.0 <1.0 583 31.1
2nd Qtr 5/23/2016 2.64 8,570 <1.0 <1.0 598 58.4
3rd Qtr 7/25/2016 <1.0 5,840 <1.0 <1.0 619 61.3
41h Qtr 10/12/2016 1.08 3 370 <1 0 <1.0 588 61.5
1st Qtr 3/8/2017 1.56 5,320 <1.0 <1.0 566 69.8
2nd Qtr 6/13/2017 1.21 3,670 <1.0 <1.0 572 70.8
3rd Qtr 7/26/2017 <1.0 5,150 <1.0 <1.0 391 66.1
41h Qtr 10/11/2017 <1.0 4,770 <1.0 <1.0 600 80.1
DWMRC spat sample <38 4,19p <60 150 J 610 79.0
1st Qtr 3/12/2018 <1.0 4,530 <1.0 <1.0 607 62.3
2nd Qtr 6/8/2018 <1.0 3,010 <1.0 <1.0 580 72.5
3rd Qtr 8/22/2018 <1.0 3,600 <1.0 <1.0 613 55.4
4th Qtr 11/28/2018 <1.0 2,680 <1.0 <1.0 567 75.7
1st Qtr 3/8/2019 1.02 4,310 <1.0 <1.0 528 71.9
2nd Qtr 6/5/2019 1.13 4,690 <1.0 <1.0 662 83.9
3rd Qtr 9/4/2019 <1.0 3,460 <1.0 <1.0 588 72.5
41 tsht QQ ttrr 12/10/2019 2/19/2020 <1.0 1.02 3,820 3,910 <1.0 <1.0 <1.0 <1.0
660068 59.9 57.7
2nd Qtr 5/27/2020 <1.0 2,530 <1.0 <1.0 578 60.5
3rd Qtr 9/4/2020 <1.0 3,760 <1.0 <1.0 514 64.8
41h Qtr 10/28/2020 6.83 3,640 <1.0 <1.0 523 64.9
(1) VOCs were resampled because laboratory mssed holding time. (2) As of March 2012 both north and south wild lite ponds no longer receiving water.
2) Chloroform Eanpinjwell started 1/213/13. NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. J = Approximated value
TABLE 1 (24 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-23
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate -1- Nitrite
(10 mg/L)
2nd Qtr 6/27/2007 <1.0 <1.0 <1.0 <1.0 47 <0.1
3rd Qtr 8/15/2007 <1.0 <1.0 <1.0 <1.0 46 <0.1
4t6 Qtr 10/10/2007 <1.0 <1.0 <1.0 <1.0 43 <0.1
1st Qtr 3/28/2008 <1.0 <1.0 <1.0 <1.0 41 <0.1
2nd Qtr 6/25/2008 <1.0 <1.0 <1.0 <1.0 41 <0.1
3rd Qtr 9/10/2008 <1.0 <1.0 <1.0 <1.0 35 <0.05
4th Qtr 10/15/2008 NA NA NA NA 51 <0.05
11/18/2008 <2.0 <2.0 <2.0 <2.0 NA NA
1st Qtr 3/4/2009 <1.0 <1.0 <1.0 <1.0 41 <0.1
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 43 <0.1
3rd Qtr 9/14/2009 <1.0 <1.0 <1.0 <1.0 43 <0.1
41h Qtr 12/16/2009 <1.0 <1.0
1st Qtr 3/24/2010 <1.0 <1.0 <1.0 <1.0 45 <0.1
2nd Qtr 6/14/2010 <1.0 <1.0 <1.0 <1.0 40 <0.1
3rd Qtr 8/24/2010 <1.0 <1.0 <1.0 <1.0 40 <0.1
4th Qtr 10/15/2010 <1.0 <1.0 <1.0 <1.0 34 <0.1
1st Qtr 2/16/2011 <1.0 <1.0 <1.0 , <1.0 44 <0.1
2nd Qtr 6/14/2011 <1.0 <1.0 <1.0 <1.0 44 <0.1
3rd Qtr 8/16/2011 <1.0 <1.0 <1.0 <1.0 41 <0.1
4th Qtr 11/15/2011 <1.0 <1.0 <1.0 0 43 <0.1
1st Qtr (1) 1/17/2012 <1.0 <1.0 <1.0 0 40 <0.1
2nd Qtr 5/31/2012 <1.0 <1.0 <1.0 <1.0 44 <0.1
3rd Qtr 8/29/2012 <1.0 <1.0 <1.0 <1.0 46 <0.1
4th Qtr 10/3/2012 <1.0 <1.0 <1.0 <1.0 45 <0.1
1st Qtr 2/7/2013 <1.0 <1.0 <1.0 <1.0 43.6 <0.1
2nd Qtr 5/30/2013 <1.0 <1.0 <1.0 <1.0 44.7 0.1
3rd Qtr 9/5/2013 <1.0 <1.0 <1.0 <1.0 48 <0.1
4t5 Qtr 11/7/2013 <1.0 <1.0 <1.0 <1.0 43 <0.1
1s1 Qtr 1/23/2014 <1.0 <1.0 <1.0 <1.0 44.6 <0.1
2nd Qtr 5/19/2014 <1.0 <1.0 <1.0 <1.0 42.3 <0.1
3rd Qtr 8/13/2014 <1.0 <1.0 <1.0 <1.0 46 <0.1
41h Qtr 10/28/2014 <1.0 <1.0 <1.0 <1,0 46.8 <0.1
lst Qtr 3/12/2015 <1.0 <1.0 <1.0 <1.0 47.3 <0.1
2nd Qtr 6/8/2015 <1.0 <1.0 <1.0 <1.0 48.4 <0.1
3rd Qtr 9/3/2015 <1.0 <1.0 <1.0 <1.0 54.1 <0.1
4th Qtr 10/28/2015 <1.0 <1.0 <1.0 <1.0 46.4 <0.1
Dephcate TW4-70 <1.0 <1.0 <1.0 <1.0 46.4 <0.1
lst Qtr 3/16/2016 <1.0 <1.0 <1.0 <1.0 49.1 <0.1
2nd Qtr 5/26/2016 <1.0 <1.0 <1.0 <1.0 50.4 <0.1
3rd Qtr 8/23/2016 <1.0 <1.0 <1.0 <1.0 49.6 <0.1
Duplicate TW4-70 <1.0 <1.0 <1.0 <1.0 48.3 <0.1
Qtr 10/12/2016
1
4th <1.0 <1.0 <1.0 <1.0 52.1 <0.1
1st Qtr 3/15/2017 <1.0 <1.0 <1.0 <1.0 47.7 <0.1
Duplicate TW4-70 <1.0 <1.0 <1.0 <1.0 49.8 <0.1
2nd Qtr 6/15/2017 <1.0 <1.0 <1.0 <1.0 51.5 <0.1
3rd Qtr 8/2/2017 <1.0 <1.0 <1.0 <1.0 51.8 <0.1
4th Qtr 10/10/2017 <1.0 <1.0 <2.0 <2.0 44.7 <0.1
DWMRC spit, seippie <1.0 <1.0 <2.0 <2.0 52 <0.1
1st Qtr 3/14/2018 <1.0 <1.0 <1.0 <1.0 53.8 <0.1
2nd Qtr 6/13/2018 <1.0 <1.0 <1.0 <1.0 47.6 <0.1
Duplicate TW4-70 <1.0 <1.0 <1.0 <1.0 47.9 <0.1
3rd Qtr 8/30/2018 <1.0 <1.0 <1.0 <1.0 56 <0.1
4th Qtr 12/12/2018 <1 0 <1.0 <1.0 <1 0 54 9 <0 1
1st Qtr 3/16/2019 <1.0 <1.0 <1.0 <1.0 48.9 <0.1
2nd Qtr 6/13/2019 <1.0 <1.0 <1.0 <1.0 50.2 <0.1
3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 47.9 <0.1
4th Qtr 12/10/2019 <1.0 <1.0 <1.0 <1.0 54.4 <0.1
1st Qtr 3/17/2020 <1.0 <1.0 <1.0 <1.0 50.0 <0.1
2nd Qtr 6/11/2020 <1.0 <1.0 <1.0 <1.0 49.0 <0.1
3rd Qtr 9/17/2020 <1.0 <1.0 <1.0 <1.0 48.8 <0.1
'4th Qtr 11/4/2020 <1.0 <1.0 <1.0 <1.0 49.3 <0.1
(1) As of March 2012 both north and south wild life ponds no longer receiving water
NA = not analyzed Shaded indicates concentrations exceeding GWQS. J = Approximated value.
TABLE 1 (25 of 31) Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation DUSA White Mesa Mill
TW4-24 (nitrate pumping well started 1/26/13)
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride (5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate -I- Nitrite (10 mg/L)
2nd Qtr 6/27/2007 <1.0 2.6 <1.0 <1.0 770 26.1
3rd Qtr 8/15/2007 <1.0 2.2 <1.0 <1.0 791 29
4t6 Qtr 10/10/2007 <1.0 1.5 <1.0 <1.0 692 24.7
1st Qtr 3/28/2008 <1.0 1.5 <1.0 <1.0 740 24.4
2nd Qtr 6/25/2008 <1.0 1.4 <1.0 <1.0 834 45.3
3rd Qtr 9/10/2008 <1.0 2.9 <1.0 <1.0 1,180 38.4
4t6 Qtr 10/15/2008 NA #N/A NA NA 1,130 44.8
11/18/2008 <2.0 <2.0 <2.0 <2.0 *N/A N/A
1st Qtr 3/4/2009 <1.0 1.4 <1.0 <1.0 1,010 30.5
2nd Qtr 6/23/2009 <1.0 1.5 <1.0 <1.0 759 30.4
3rd Qtr 9/14/2009 <1.0 1.4 <1.0 <1.0 618 30.7
4th Qtr 12/16/2009 <1.0 1.2 <1.0 <1.0 .......19.§.9. 28.3
l st Qtr 3/25/2010 <1.0 1.3 <1.0 <1.0 896 33.11
2nd Qtr 6/14/2010 <1.0 1.7 <1.0 <1.0 639 30
3rd Qtr 8/24/2010 <1.0 1.8 <1.0 <1.0 587 31
4th Qtr 10/15/2010 <1.0 1.4 <1.0 <1.0 522 31
1st Qtr 2/16/2011 <1.0 1.8 <1.0 <1.0 1,100 31
2nd Qtr 6/14/2011 <1.0 1.1 <1.0 <1.0 1,110 35
3rd Qtr 8/16/2011 <1.0 1.7 <1.0 <1.0 967 34
4th Qtr 11/15/2011 NA #N/A NA NA 608 35
....W. 12/7/2011 <1.0 1.2 <1.0 • <1.0 #N/A #N/A
Iš(air (2.) 1/16/2012 <1.0 <1.0 <1.0 <1.0 373 37
2nd Qtr 6/6/2012 <1.0 <1.0 <1.0 <1.0 355 37
3rd Qtr 8/30/2012 <1.0 <1.0 <1.0 <1.0 489 37
4th Qtr 10/3/2012 <1.0 1 <1.0 <1.0 405 38
1st Qtr (3) 2J11/2013 <1.0 1 <1.0 <1.0 1,260 35.9
2nd Qtr 6/5/2013 <1.0 17.4 <1.0 <1.0 916 23.7
3rd Qtr 8/30/2013 <1.0 21.8 <1.0 <1.0 998 33
41h Qtr 10/29/2013 <1.0 32.5 <1.0 <1.0 1,030 35
1st Qtr 1/27/2014 1.18 78.5 <1.0 <1.0 809 31.6
2nd Qtr 5/19/2014 <1.0 62.7 <1.0 <1.0 1,020 35.0
3rd Qtr 8/11/2014 <1.0 76.3 <1.0 <1.0 1,150 31.5
4th Qtr 10/21/2014 <1.0 25.8 <1.0 <1.0 1,050 35.7
1st Qtr 3/9/2015 <1.0 49.2 <1.0 <1.0 944 34.6
2nd Qtr 6/8/2015 <1.0 4.28 <1.0 <1.0 1,290 31.8
3rd Qtr 8/31/2015 <1.0 46.9 <1.0 <1.0 788 25.3
4th Qtr 10/19/2015 <1.0 25.3 <1.0 <1 0 909 29.6
1st Qtr 3/9/2016 <1.0 22.8 <1.0 <1.0 989 29.1
2nd Qtr 5/23/2016 <1.0 69.6 <1.0 <1.0 771 24.2
3rd Qtr 7/25/2016 <1.0 17.8 <1.0 <1.0 1,180 34.4
4th Qtr 10/12/2016 <1.0 20.8 <1.0 <1.0 1010 31.9
1st Qtr <1.0 18.3 <1.0 <1.0 1,090 41.3
2nd Qtr 6/13/2017 <1.0 17.2 <1.0 <1.0 1,080 39.9
3rd Qtr 7/26/2017 <1.0 17.8 <1.0 <1.0 1,230 40.0
4th Qtr 10/11/2017 <1.0 16.0 <1.0 <1.0 895 31.7
pvvMRC .k?!!!..?9.11,1f <0.38 36.0 <0.60 1.3 J IA 00 32.0
1st Qtr 3/16/2018 <1.0 24.9 <1.0 < .0 1,320 44.9
2nd Qtr 6/14/2018 <1.0 49.2 <1.0 <1.0 792 33.6
3rd Qtr 8/22/2018 <1.0 35 <1.0 <1.0 996 33.8
4t5 Qtr 11/28/2018 <1.0 21 <1.0 <1.0 1,100 38.4
DV)/MRC split samp)e <5.0 60 <5.0 <5.0 1,000 34.0
1st Qtr 3/8/2019 <1.0 28.1 <1.0 <1.0 1,040 39.3
2nd Qtr 6/5/2019 <1.0 28.8 <1.0 <1.0 1,020 33.2
3rd Qtr 9/4/2019 <1.0 31.1 <1.0 <1.0 1,130 36.4
4th Qtr 12/10/2019 <1.0 43.3 <1.0 <1.0 1,090 33.8
1st Qtr 2/19/2020 <1 0 61.7 <1.0 <1.0 1,010 37.1
2nd Qtr 5/27/2020 <1.0 49.4 <1.0 <1.0 1,060 41.7
3rd Qtr 9/4/2020 <1.0 . 63 8 <1 0 . <1.0 1,100 39.1
4th Qtr 10/28/2020 <1.0 72.6 <1.0 <1.0 1,050 35.9
(1) VOCs were resampled beca se laboratory missed holding time. (2) As of Mar,n 2012 both north and south wild life ponds no longer receiving water.
2.) Chloroform pumprntwell started 1/26/13.
NA = not analyzed Shaded indicates concentrations exceeding GWCIS.
J = Approximated value
TABLE 1 (26 of 31) Historic Summary Of Monitoring Well Analytical Resuks Up To The 4th Qarter 2020
Chloroform Contamination Investigation DUSA White Mesa Mill
TW4-25 (nitrate pumping well started 1/26/13) Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L) Nitrate, Nitrate e. Nitrite
(10 mg/L)
2nd Qtr , 6/27/2007 <1.0 <1.0 <1.0 <1.0 395 17.1
3rd Qtr 8/15/2007 <1.0 2.2 <1.0 <1.0 382 29
4th Qtr 10/10/2007 <1.0 <1.0 <1.0 <1.0 358 17
lst Qtr 3/28/2008 <1.0 <1.0 <1.0 <1.0 374 18.7
2nd Qtr 6/25/2008 <1.0 <1.0 <1.0 <1.0 344 22.1
3rd Qtr 9/10/2008 <1.0 <1.0 <1.0 <1.0 333 . .„ . 18.8
41h Qtr 10/15/2008 NA #N/A NA NA 366 21.3
11/18/2008 <2.0 <2.0 <2.0 <2.0 #N/A #N/A
1st Qtr 3/4/2009 <1.0 <1.0 <1.0 <1.0 3 15.3
2nd Qtr 6/23/2009 <1.0 <1.0 <1.0 <1.0 328 - 15.3
3rd Qtr 9/14/2009 <1.0 <1.0 <1.0 <1.0 328 3.3
4th Qtr 12/16/2009 <1.0 <1.0 <1.0 <1.0 371 14.2
1st Qtr 3/23/2010 <1.0 <1.0 <1.0 <1.0 296 14:4
2nd Qtr 6/14/2010 <1.0 <1.0 <1.0 <1.0 306 16
3rd Qtr 8/10/2010 <1.0 <1.9 <1.0 <1.0 250 14
4th Qtr 10/15/2010 <1.6 .i.o <1.0 <1.0 312 15.
1st Qtr 2/16/2011 <1.0 1.8 <1.0 <1.0 315 -15
nd Qtr 5/25/2011 <1.0 <1.0 <1.0 <10 321 16
3rd Qtr 8/16/2011 <1.0 <1.0 <'1 .0 <1.0 276 16
41h Qtr 11/15/2011 <1.0 <1.0 <1.0 <1.0 294 16
1st Qtr (2) 1/16/2012 <1.0 <1.0 <1.0 <1.0 304 18
2nd Qtr 5/31/2012 <1.0 <1.0 <1.0 <1.0 287E 16
3rd Qtr 9/4/2012 <1.0 <1.0 <1.0 <1.0 334 17
4th Qtr 10/3/2012 <1.0 <'1 0 <1.0 <1.0 338 17
1st Qtr (3) 2/11/2013 . „ .. <1.0 <1.0 <1.0 <1.0 190 9.04
2nd Qtr 6/5/2013 <1.0 <1.0 <1.0 <1.0 136 5.24
3rd Qtr 9/4/2013 <1.0 <1.0 <1.0 <1.0 119 5.69
4th Qtr 10/31/2013 <1.0 <1.0 <1.0 <1.0 88.6 6.1
1st Qtr 1/27/2014 <1.0 <1.0 <1.0 <1.0 85.7 2.16
2nd Qtr 5/19/2014 <1.0 <1.0 <1.0 <1.0 51.1 1.21
3rd Qtr 8/11/2014 <1.0 <1.0 <1.0 <1.0 67 1.6
41h Qtr 10/21/2014 <1.0 <1.0 <'1 .0 <1.0 .....581. 1.03
1st Qtr 3/9/2015 <1.0 <1.0 <1.0 <1.0 310 14.4
2nd Qtr 6/8/2015 <1.0 <1.0 <1.0 <1.0 58.3 1.14
3rd Qtr 8/31/2015 <1.0 <1.0 <1.0 <1.0 69.2 1.63
4th Qtr 10/19/2015 <1.0 <1.0 <1.0 <1.0 93 7 1.78
1st Qtr 3/9/2016 <1.0 <1.0 <1.0 <1.0 62.7 0.837
2nd Qtr 5/23/2016 <1.0 <1.0 <1.0 <1.0 75.5 0.959
3rd Qtr, 7/25/2016 <1.0 <1.0 <1.0 <1.0 74.1 1.78
4t6 Qtr 10/12/2016 <1.0 <1.0 <1.0 <1.0 59.8 1.24
1st Qtr 3/8/2017 <1.0 1.15 <1.0 <1.0 285 17.0
2nd Qtr 6/13/2017 <1.0 <1.0 <1.0 <1.0 69.8 0.976
3rd Qtr 7/26/2017 <1.0 <1.0 <1.0 <1.0 70.1 1.23 4t6 Qtr 10/11/2017 <1.0 <1.0 <1.0 <1.0 ......,!?.. ...1.19.
lstQtr 3/12/2018 <1.0 1.15 <1.0 <1.0 70.5 2.23
2nd Qtr 6/14/2018 <1.0 <1.0 „. <1.0 <1.0 60.3 1.14
3rd Qtr 8/22/2018 <1.0 <1.0 <1.0, <1.0 69.1 0.810
41h Qtr 11/28/2018 <1.0 <1.0 <1.0 <1.0 59.7 0.634
1st Qtr 3/8/2019 <1.0 <1.0 <1.0 <1.0 65 0.639
2nd Qtr 6/5/2019 <1.0 ,<1.0 <1.0 59 0.821
3rd Qtr 9/4/2019 <1.0 <1.0 <1.0 <1.0 58.1 0.548
4th Qtr 12/10/2019 <1.0 <1.0 <1.0 <1.0 73.1 0&.1,1 1st Qtr 2/19/2020 <1.0 <1.0 <1.0 <1.0 86.0 0.607 .
2nd Qtr 5/27/2020 <1.0 <1.0 <1.0 <1.0 76.8 0.851
3rd Qtr 9/4/2020 <1.0 <1.0 <1.0 <1.0 67.3 0.994
4th Qtr 10/28/2020 <1.0 <1.0 <1.0 <1.0 61.3 1.64
(1) VOCs were resampled because laboratory missed holding time. (2) As of March 2012 both north and south wild life ponds no longer receiving water.
O.) Chloroforrn einping_well started 1/26113.
NA = not analyzed Shaded indicates concentrations exceeding GWQS.
TABLE 1 (27 of 31) Historic Summary Of Monitoring Well Analytical Results Up To The 4th garter 2020
Chloroform Contamination Investigation DUSA White Mesa Mill
TW4-26 Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate -i- Nitrite
(10 mg/L)
2nd Qtr 6/14/2010 <1.0 13 <1,0 <1.0 33 7.9
3rd Qtr 8/24/2010 <1.0 5.2 <1.0 <1.0 17 9.0
4th Qtr 10/15/2016 <1.0 5.4 <1.0 <1.0 22
.
9.6
151 Qtr 2/16/2011 <1.0 2 <1.0 <1.0 30 19.0
2nd Qtr 5/26/2011 , <1.0 2.9 <1.0 <1.0 15 10.0
3rd Qtr 8/17/2011 <1.0 2.8 <1.0 <1.0 19 11.0
4th Qtr 11/16/2011 NA *N/A NA NA , 26 10.0
...(:9 12/7/2011 <1.0 5.2 <1.0 <1.0 *N/A *N/A
'filar (2) 1/18/2012 <1.0 7 <1.0 <1.0 17 11.0
2nd Qtr 6/6/2012 <1.0 4.1 <1.0 <1.0 .19. 12.0
3rd Qtr 9/11/2012 <1.0 4.9 <1.0 <1.9 19 9.0
41h Qtr 10/3/2012 <1.0 4.9 <1.0 <1.0 19 12.0
1st Qtr 2111/2013 <1.0 4.9 <1.0 <1.0 16.6 12.5
2nd Qtr 6/13/2013 <1.0 2.12 <1.0 <1.0 14.5 13.6
3rd Qtr 9/5/2013 <1.0 2.81 <1.0 <1.0 , 17.6 11.7
4th Qtr 11/7/2013 <1.0 3.37 <1.0 <1.0 15.9 15.9
1st Qtr 1/29/2014 <1.0 1.43 <1.0 <1.0 16.9 14.2
2nd Qtr 5/21/2014 <1.0 4.23 <1.0 <1.0 15.4 12.5
3rd Qtr 8/11/2014 <1.0 1.3 <1.0 <1.0 15 10.8
4t5 Qtr 10/28/2014 <1.0 2.45 <1.0 <1.0 14.6 1.2.: 1st Qtr 3/12/2015 <1.0 2.37 <1.0 <1.0 14.4 144 „.„. 2nd Qtr 6/10/2015 <1.0 6.12 1.17 <1.0 14.4 11.3
3rd Qtr 9/3/2015 <1.0 4.77 <1.0 <1.0 14 14,2
4th Qtr 10/28/2015 <1 0 3 45 <1.0 <1.0 13.3 13.9
1s1 Qtr 3/16/2016 <1.0 1.8 <1.0 <1.0 13.7 16.9
2nd Qtr 5/26/2016 <1.0 8.23 <1.0 <1.0 15.2 13.9
3rd Qtr 8/3/2016 <1.0 4.42 <1.0 <1.0 13.9 17.9
4t5 Qtr 10/20/2016 <1.0 19.9 <1.0 <1.0 14.2 15.0
1st Qtr 3/16/2017 <1.0 46.1 <1.0 <1.0 16.2 15.8
2nd Qtr 6/20/2017 <1.0 244 <1.0 <1.0 19 15.2
3rd Qtr 8/3/2017 <1.0 419 <1.0 <1.0 25.8 15.2
41h Qtr 10/11/2017 <1.0 608 <1.0 <1.0 27.3 10.0
1st Qtr 3/21/2018 <1.0 1,050 <1.0 <1.0 35.5 12.2
2nd Qtr 6/14/2018 <1.0 966 <1.0 <1.0 33.5 13.2
3rd Qtr 9/6/2018 <1.0 916 <1.0 <1.0 38.9 13.5
4th Qtr 12/13/2018 <1.0 1.950 <1.0 <1.0 33.4 11.8
1st Qtr 3/20/2019 <1.0 963 <1.0 <1.0 32.9 12.2
2nd Qtr 6/5/2019 <1.0 1,070 <1.0 <1.0 35.8 12.6
3rd Qtr 9/12/2019 <1.0 877 <1.0 <1.0 32.0 10.9
4th Qtr 12/18i2619 <1.0 1,970 <to <1.0 38.3 1.9.:
1st Qtr 3118/2020 <1.0 1,090 <1.0 <1.0 36.3 11.6
2nd Qtr 6/12/2020 <1.0 1,140 <1.0 <1.0 35.1 11.1
3rd Qtr 9/19/2020 <1.0 1120 <1.0 <1.0 34.8 10.5
4th Qtr 11/11/2020 <1.0 1,130 <1.0 <1.0 36.3 11.9
TW4-27 1st Qtr (2) 1118/2012 <1.0 9 <1.0 <1.0 11 24.0
2nd Qtr 6/13/2012 <1.0 <1.0 <1.0 17 41.0
3rd Qtr 9/4/2012 <1.0 <1.0 <1.9 <1.0 21 37.0
4t8 Qtr 10/3/2012 <1.0 <1.0 <1.0 <1.0 18 36.0
1st Qtr 2/7/2013 <1.0 <1..0 <1.0 <1.0 18.8 , 31.2
2nd Qtr 6/13/2013 <1.0 <1.0 <1.0 <1.0 20.3 29.4
3rd Qtr 8/30/2013 <1.0 <1..0 <1.0 <1.0 19 27.2
!416 Qtr 11/6/2013 <1.0 <1.0 <1.0 <1.0 21.8 29.8
1st Qtr, 1/23/2014 <1.0 <1.0 <1.0 <1.0 31.8 31.3
2nd Qtr 5/21/2014 <1.0 <1.0 <1.0 <1.0 20.6 31.1
3rd Qtr 8/13/2014 <1.0 <1 .,0 <1.0 <1.0 23 27.0
4th Qtr 10/28/2014 <1.0 <1.0 <1.0 <1.0 24.4 28.2
1st Qtr 3/11/2015 <1.0 <1.0 <1.0 <1.0 26.2 26.5
2nd Qtr 6/10/2015 <1.0 <1.0 <1.0 <1.0 26.8 24.0
3rd Qir 9/2/2015 <1.0 1.3 <1.0 <1.0 26.8 20.9
4th Qtr 10/28/2015 <1.0 1 6 <1 0 <1.0 26 2 23.5
1st Qtr 3/16/2016 <1.0 2.11 <1.0 <1.0 28 25.6
2nd Qtr 5/26/2016 <1.0 3.16 <1.0 <1.0 21.2 28.7
3rd Qtr 8/3/2016 , <1.0 2.78 <1.0 <1.0 27.1 21.8
4th Qtr 10/20/2016 <1.0 3.8 <1.0 <1.0 29.,4. 19.:.
lst Qtr 3/15/2017 <1.0 4.33 <1.0 <1.0 .8.3 22.2
2nd Qtr 6/15/2017, <1.0 5.65 <1.0 <1.0 27.9 23.8
3rd Qtr 8/2/2017 <1.0 6.05 <1.0 <1.0 29.5 20.0
4th Qtr 10/10/2017 <1.0 5.91 <1.0 <1.0 26.3 21.5
1st Qtr 3/14/2018 <1.0 6.95 <1.0 <1.0 30.3 19.5
2nd Qtr 6/13/2018 <1.0 5.95 <1.0 <1.0 28.3 22.0
3rd Qtr 8/30/2018 <1.0 . 7 35 <1 0 . <1.0 31.4 18.1
4t5 Qtr 12/12/2018 <1.0 7.7 <1.0 <1.0 28.2 20.8. 1st Qtr 3/16/2019 <1.0 6.54 <1.0 <1.0 26.2 21.5
2nd Qtr 6/13/2019 <1.0 8.24 <1.0 <1.0 28.6 22.3
3rd Qtr 9/11/2019 <1,0 7.58 <1,0 <1.0 25.3 21.2
41h Qtr 12/14/2019 <1.0 7.97 <1.0 <1.0 27.4 12..9. 1st Qtr 3/18/2020 <1.0 8.04 <1.0 <1.0 2.7.6 23.6
2nd Qtr 6/11/2020 <1.0 7.92 <1.0 <1.0 28.0 21.5
3rd Qtr 9/18/2020 <1.0 5.62 <1.0 <1.0 26.2 25.2
41h Qtr 11/4/2020 <1.0 7.8 <1 0 <1.0 26.8 16.7
(1) VOCs were resampled because laboratory missed holding time. (2) As of March 2012 both north and south wild life ponds no longer receiving water.
NA = not analyzed Shaded indicates concentrations exceeding GWQS.
TABLE 1 (28 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020 Chloroform Contamination investigation
DUSA White Mesa Mill
TW4-28
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate . Nitrite
(10 mg/L)
2nd Qtr 6/19/2013 01.0 <1.0 <1.0 <1.0 44.6 „ 14.9
3rd Qtr 8/29/2013 <1.0 <1.0 <1.0 <1.0 45.3 17.3
4th Qtr 11/6/2013 <1.0 <1.0 <1.0 <1.0 16.2 _....._. .........__ l at Qtr 1/22/2014 <1.0 <1.0 <1.0 <1.0 4.8 16.9
2nd Qtr, 5/21/2014 <1.0 <1.0 <1.0 <1.0 45.7 16.5
3rd Qtr 8/13/2014 <1.0 <1.0 <1.0 <1.0 50 14.2
4th Qtr 10/23/2014 <1.0 <1.0 <1.0 <1.0 ...,1. 16.5
1st Qtr 3/11/2015 <1.0 <1.0 <1.0 <1.0 52.2 19.0
2nd Qtr 6/10/2015 <1.0 <1.0 <1.0 <1.0 56.4 19.0
3rd Qtr 9/2/2015 01.0 <1.0 <1.0 <1.0 61.4 17.8
41h Qtr 10/21/2015 <1.0 <1 a <1.0 <1.0 52.7 18 7
1st Qtr 3/15/2016 <1.0 <1.0 <1.0 <1.0 61.6 34.0
Duphcate TW4-66 <1.0 <1.0 <1.0 <1.0 61 4 32.6
2nd Qtr 5/25/2016 <1.0 <1.0 <1.0 < to_ , 29.0
3rd Qtr 7/27/2016 <1.0 <1.6 <1.0 <1.0 70.1 31.3
Duplicate TW4-65 <1.0 <1.0 „ „. <1.0 <1.0 70.9 35.6
4th Qtr 10/19/2016 <1.0 <1.0 <1.0 <1.0 70.9 25.5
Dup.1pete1W4-65 <1.0 <1.0 <1.0 73/ 25.4
1st Qtr 3/14/2017 <1.0 <1.0 <1.0 <1.0 64.2 24.4
Duplicate TW4-65 <1.0 <1.0 <1.0 <1.0 66.4 , 27.9
2nd Qtr 6/14/2017 <1.0 <1.0 <1.0 <1.0 68.6 26.0
3rd Qtr 7/27/2017 <1.0 <1.0 <1.0 <1.0 67.1 24.8
4th Qtr 10/10/2017 <1.0 <1.0 <1.0 <1.0 57.4 24.8
1st Qtr 3/14/2018 <1.0 <1.0 <1.0 <1.0 65.0 17 2 .
2nd Qtr 6/12/2018 <1.0 <1.0 <1.0 <1.0 55.7 19.0
Duplicate TW4-65 <1.0 <1.0 <1.0 01.0 56.7 18.7
3rd Qtr , <1.0 <1.0 <1.0 <1.0 63.8 16.0
4th Qtr 11/30/2018 <1.0 <1.0 <1.0 <1.0 52.4 17.7
15t Qtr 3/16/2019 <1.0 <1.0 <1.0 <1.0 51.7 17.2
2nd Qtr 6/13/2019 <1.0 <1.0 <1.0 <1.0 51.8 15.0
3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 49.0 10.2
4t8 Qtr 12/12/2019 <1.0 <1.0 <1.0 <1.0 50.0 9.48
1st Qtr 3/17/2020 <1.0 <1.0 <1.0 <1.0 52.1 9.67
2nd Qtr 6/10/2020 <1.0 <1.0 <1.0 <1.0 49.8 9.55
3rd Qtr 9/17/2020 <1.0 <1.0 <1.0 <1,0 47.4 8.36
4th Qtr 11/4/2020 <1.0 <1.0 <1.0 <1 0 49.0 7.76
TW4-29
2nd Qtr 6/19/2013 <1.0 242 <1.0 <1.0 44.8 , 4.60
2nd Qtr 7/11/2013 <1.0 262 <1.0 <1.0 37.7 3.52
3rd Qtr 9/26/2013 , <1.0 246 <1.0 <1.0 41.4 4.18
4t6 Qtr 11/13/2013 <1,0 260 <1.0 <1.0 42.5 4.11
1st Qtr 2/5/2014 <1.0 258 <1.0 <1.0 14.9 4.63
2nd Qtr 5/22/2014 <1.0 262 <1.0 <1.0 38.2 3.52
3r4 Qtr 8/27/2014 <1.0 242 <1.0 <1.0 „ „. . 41 3.40
41h Qtr 10/29/2014 <1.0 290 <1.0 <1.0 41 3.64
1st Qtr 3/12/2015 <1.0 299 <1.0 <1.0 40.5 4.14
2nd Qtr 6/11/2015 <1.0 329 <1.0 <1.0 42.5 2.95
3rd Qtr 9/3/2015 <1.0 276 <1.0 <1.0 47.3 2.19
41h Qtr 10/29/2015 <1 0 631 <1 0 <1 0 39 8 2 74
1st Qtr 3/17/2016 <1.0 335 , <1.0 <1.0 40.5 2.92
2nd Qtr 6/8/2016 , <1.0 366 <1.0 <1.0 42.9 2,51
3rd Qtr 8/3/2016 <1.0 401 <1.0 <1 0 „„.......... 40.6 2.44
4th Qtr 10/26/2016 <1.0 392 <1.0 <1.0 44.2 2.40
1st Qtr 3/16/2017 <1.0 446 <1.0 <1.0 41.5 2.24
2nd Qtr 6/4/2017 <1.0 „ 420 <1.0 <1.0 42 2.26
3rd Qtr 8/4/2017 <1.0 466 <1.0 <1.0 42.9 , 2.35
4th Qtr 10/11/2017 <1.0 431 <1.0 <1.0 37.7 2.45
1st Qtr 3/14/2018 <1.0 533 <1.0 <1.0 43.1 2.44
2nd Qtr 6/14/2018 <1.0 474 <1.0 <1.0 40.1 2.67
3rd Qtr 8/29/2018 <1.0 454 <1.0 <1.0 45.9 2.52
4th Qtr 12/13/2018 <1.0 521 <1.0 <1.0 40.9 2.50
1st Qtr 3/20/2019 <1.0 , 507 <1.0 <1.0 39.9 2.67
2nd Qtr 6/13/2019 <1.0 537 <1.0 <1.0 39.4 2,56
3rd Qtr 9/12/2019 <1.0 549 <1.0 <1.0 38 2.55
4th Qtr 12/18/2019 <1.0 630 <1.0 <1.0 44.8 2.58
1st Qtr 3/18/2020 <1.0 652 <1.0 <1.0 41, 3.10
2nd Qtr 6/12/2020 <1.0 686 <1.0 42.2 3.18
3rd Qtr, 9/19/2020 <1.0 621, <1.0 01.0 39.9 „ 2.90
41h Qtr 11/11/2020 <1.0 671 <1.0 <1.0 40.8 3.27
DWMRC split sample <10 670 <20 <20 42 0.75 H
H = Sample was analyzed beyond holdin times and ma not be accureate coneentraton.
TW4-30
2nd Qtr 6/19/2013 <1 0 <1 0 <1 0 <1.0 36 0.95
3rd Qtr 9/26/2013 <1 0 <1.0 <1.0 <1.0 36.3 0.952
4th Qtr 11/13/2013 <1.0 <1.0 <1 0 <1.0 35.9 1 24
1st Qtr 1/23/2014 <1.0 <1.0 <1.0 <1 0 36.9 1,36
2nd Qtr 5/22/2014 <1.0 <1 0 <1.0 <1.0 31.? 1.44
3rd Qtr 8/23/2014 <1.0 <1.0 <1 0 <1 0 38 1.5
418 Qtr 10/23/2014 <1.0 <1.0 <1.0 <1 0 37.1 1.84
1st Qtr 3/11/2015 <1.0 1.65 <1.0 <1 0 38.3 2.15
2nd Qtr 6/11/2015 <1.0 2.25 <1 0 <1.0 40.3 1.75
3rd Qtr 9/3/2015 <1.0 3.27 <1.0 <1 0 44,2 1.75
41h Qtr 10/28/2015 <1 0 348 <1 0 <1 0 37 8 1 86
1st Qtr 3/17/2016 <1.0 5.16 <1.0 <1.0 39 6 2.74
2nd Qtr 5/26/2016 <1.0 7.38 <1.0 <1.0 40.2 2.04
3rd Qtr 8/3/2016 <1.0 6.79 <1.0 <1.0 38.6 2.32
4th Qtr 10/20/2016 <1.0 8.69 <1.0 <1.0 41 3 2.51
1st Qtr 3/15/2017 <1.0 13.6 <1.0 <1.0 37 7 2.70
2nd Qtr 6/15/2017 <1.0 15.2 <1.0 <1.0 37.8 2.95
3rd Qtr 8/3/2017 <1.0 15.7 <1.0 <1.0 39.8 3.11
4th Qtr 10/10/2017 <1 0 13.4 <1.0 <1.0 34.9 2.58
1st Qtr 3/15/2018 <1 0 16.4 <1.0 <1.0 41 3.63
2nd Qtr 6/13/2018 <1 0 16.9 <1.0 <1.0 37.4 3.93
3rd Qtr 8/30/2018 <1 0 19.8 <1.0 <1 0 44.1 3.79
41h Qtr 12/12/2018 <1 0 23 9 <1.0 <1 0 35.5
1st Qtr 3/15/2019 25.3 <1.0 <1.0 35 9 4.08
2nd Qtr 6/13/2019 <1.0 31.5 <1.0 <1.0 27 2 4.13
3rd Qtr 9/11/2019 <1 0 34.8 <1.0 <1 0 34.5 3.79
4th Qtr 12/18/2019 <1.0 44.9 <1.0 <1 0 3.62
1st Qtr 3/17/2020 <1.0 53.1 <1.0 <1.0 37.5 3,86
2nd Qtr 6/12/2020 <1 0 65.4 <1.0 <1.0 38.6 3.69
3rd Qtr 9/18/2020 <1 0 67.7 <1.0 <1.0 35 3.49
41h Qtr 11/11/2020 <1 0 82.8 <1.0 <1.0 37.1 3.64
DWMRC split sample <10 66 <20 <20 39 <0.5 H
Shaded indicates concentrations exceeding GWQS. H 7 Sample was analyzed beyond holding times and may not be accureate concentration.
TABLE 1 (29 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-31
Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform
(70 pg/L)
Chloromethane
(30 pg/L)
Methylene Chloride
(5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate * Nitrite
(10 mg/L)
2nd Qtr 6/19/2013 <1.0 <1.0 <1.0 <1.0 28.4 1.3
3rd Qtr 9/5/2013 <1.0 <1.0 <1.0 <1.0 29.4 1.1
4th Qtr 11/7/2013 <1.0 <1.0 <1.0 <1.0 28 1.33
1st Qtr 1/23/2014 <1.0 <1.0 <1.0 <1.0 28.5 1.32
2nd Qtr 5/21/2014 <1.0 <1.0 <1.0 <1.0 26.3 1.32
3rd Qtr 8/13/2014 <1.0 <1.0 <1.0 <1.0 30 1.1
4th Qtr 10/28/2014 <1.0 <1.0 <1.0 <1.0 37.1 1.84
1st Qtr 3/11/2015 <1.0 <1.0 <1.0 <1.0 30.6 1.33
2nd Qtr 6/10/2015 <1.0 <1.0 <1.0 <1.0 31.1 1.19
3rd Qtr 9/2/2015 <1.0 <1.0 <1.0 <1.0 30.4 0.916
4th Qtr 10/21/2015 <1 0 <1 0 <1 0 <1.0 29 1 0 953
1st Qtr 3/11/2016 <1.0 <1.0 <1.0 <1.0 31.5 1.84
2nd Qtr <1.0 <1.0 <1.0 <1,.0 32.5 1.36
3rd Qtr 7/28/2016 <1.0 <1.0 <1.0 <1.0 30.6 1.41
4th Qtr 10/20/2016 <1.0 <1.0 <1.0 <1.0 34 1.14
1st Qtr 3/15/2017 <1.0 <1.0 <1.0 <1.0 31.3 1.19
2nd Qtr 6/15/2017 <1.0 <1.0 <1.0 <1.0 33.4 1.21
3rd Qtr 8/2/2017 <1.0 <1.0 <1.0 <1.0 33 1.11
41h Qtr 10/10/2017 <1.0 <1.0 <1.0 <1.0 30.9 1.04
1st Qtr 3/14/2018 <1.0 <1.0 <1.0 <1.0 38.8 0.916
2nd Qtr 6/12/2018 <1.0 <1.0 <1.0 <1.0 34.4 0.948
3rd Qtr 8/29/2018 <1.0 <1.0 <1.0 <1.0 40.3 0.710
4th Qtr 12/12/2018 <1.0 <1.0 <1.0 <1.0 35.2 0.766
1st Qtr 3/16/2019 <1.0 <1.0 <1.0 <1.0 35 0.754
2nd Qtr 6/13/2019 <1.0 <1.0 <1.0 <1.0 36.9 0.713
3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 35.8 0.61
41h Qtr 12/14/2019 <1.0 <1.0 <1.0 <1.0 40.6 ...... 1st Qtr 3/17/2020 <1.0 <1.0 <1.0 <1.0 38.2 0.573
2nd Qtr 6/12/2020 <1.0 <1.0 <1.0 , <1.0 36.7 0.569
3rd Qtr 9/17/2020 <1.0 <1.0 <1.0 <1.0 36.5 0.51:
41h Qtr 11/4/2020 <1.0 <1.0 <1.0 <1.0 36.4 0.501
TW4-32
4th Qtr 11/14/2013 <1.0 <1.0 <1.0 <1.0 52.1 4.26
1st Qtr 1/22/2014 <1.0 <1.0 , <1,0 , <1.0 54.5 5.11
2nd Qtr 5/21/2014 <1.0 <1.0 <1.0 <1.0 54.9 5.63
3rd Qtr 8/13/2014 <1.0 <1.0 <1.0 <1.0 04 4.2
41h Qtr 10/23/2014 <1.0 <1.0 <1.0 <1.0 62.6 2.14
1st Qtr 3/11/2015 <1.0 <1.0 <1.0 <1.0 64.2 2.46
Duplicate TW4-65 <1.0 <1.0 <1.0 <1.0 65.9 2.25
25d Qtr 6/10/2015 <1.0 <1.0 <1.0 <1.0 62.7 1.21
3rd Qtr 9/2/2015 <1.0 <1.0 <1.0 <1.0 59S 5.09
4th Qtr 10/21/2015 <1 0 <1 0 <1 0 <1 0 55 1 1.19
1st Qtr 3/15/2016 <1.0 <1.0 <1.0 <1.0, 64.2 4.48
2nd Qtr 5/25/2016 <1.0 <1.0 <1.0 <1.0 71.8 3.16
3rd Qtr 7/28/2016 <1.0 <1 0 <1 0 <1.0 64.4 3 44
4t5 Qtr 10/19/2016 <1.0 <1.0 <1.0 <1.0 66 2.87
15t Qtr 3/17/2017 <1.0 <1.0 <1.0 <1.0 62.8 2.83
2nd Qtr 6/15/2017 <1.0 <1.0 <1.0 <1.0 53.5 2.37
3rd Qtr 8/2/2017 <1.0 <1.0 <1.0 65.8 2.47
41h Qtr 10/10/2017 <1.0 <1.0 <1.0 <1.6 ' ' ' 65.8 2.47
1st Qtr 3/14/2018 <1.0 <1.0 <1.0 <1.0 65.4 2.94
2nd Qtr 6/12/2018 <1.0 <1.0 <1.0 <1.0, 59.2 2.51
3rd Qtr 8/29/2018 <1.0 <1.0 <1.0 <1.0 68.1 2.56
41h Qtr 11/30/2018 <1.0 <1.0 <1.0 <1.0 57.5 2.50
1st Qtr 3/16/2019 <1.0 <1.0 <1.0 <1.0 57.5 2.15
2nd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 60.1 2.18
3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 55 1.84
415 Qtr 12/14/2019 <1.0 <1.0 <1.0 <1.0 64.7 1.89
1st Qtr 3/17/2020 <1.0 <1.0 <1.0 <1.0 59.7 1.97
2nd Qtr 6/10/2020 <1.0 <1.0 <1.0 <1.0 57.0 2.19
3rd Qtr 9/17/2020 <1.0 <1.0 , <1.0 <1.0 50.8 1.58
41h Qtr 11/4/2020 <1.0 <1.0 <1.0 <1.0 53.7 1.74
TW4-33
41h Qtr 11/14/2013 <1.0 126 <1.0 <1.0 47.2 1.82
1st Qtr 1/30/2014 <1.0 124 <1.0 <1 0 43.5 , 2.56
2nd Qtr 5/22/2014 <1.0 121 <1.0 <1.0 46.8 1.63
3rd Qtr 8/27/2014 <1.0 104 <1.0 <1.0 43 1.50
4.10...g.P".......... ..1.9(.?.?!.?.21...1. <1 0 124 <1 0 <1 0 44 2 2 22
1st Qtr 3/12/2015 <1.0 134 <1.0 <1.0 44.2 1.91
2nd Qtr 6/11/2015 <1.0 127 <1.0 <1.0 46.6 1.62
3rd Qtr 9/3/2015 <1.0 123 <1.0 , <1,0 53.3 1.64
4th Qtr 10/29/2015 <1.0 129 <1.0 <1.0 44.5 1.92
1st Qtr 3/17/2016 <1.0 122 <1.0 <1.0 46.2 2.13
2nd Qtr 6/8/2016 <1.0 96.1, <1.0 <1.0 49.7 2.06
3rd Qtr 8/4/2016 <1.0 lit <1.0 <1.0 48.5 2.32
41h Qtr 10/26/2016 <1.0 109 <1.0 <1.0 52.4 ?.:§. 1st Qtr 3/17/2017 <1.0 90.7 <1.0 <1.0 49.0 i2.11
2nd Qtr 6/20/2017 <1.0 103 <1.0 , <1.0 49.2 2.34
3rd Qtr 8/3/2017 <1.0 127 <1.0 <1.0 46.9 2.04
41h Qtr 10/11/2017 <1.0 97.1 <1.0 <1.0 42.5 .2.:09.
lst Qtr 3/15/2018 <1.0 128 <1.0 <1.0 49.2 1.04
2nd Qtr 6/13/2018 <1.0 87.8 <1.0 <1.0 44.0 2.13
3rd Qtr 9/5/2018 <1.0 113 <1.0 <1.0 50.0 1.82
4th Qtr 12/13/2018 <1.0 141 <1.0 <1.0 43.2 2.01
1st Qtr 3/20/2019 <1.0 86.2 <1.0 <1.0 47.2 2.00
2nd Qtr 6/19/2019 <1.0 121 <1.0 <1.0 43.4 2.16
3rd Qtr 9/12/2019 <1.0 101 <1.0 <1.0 41.1 1.61
4th Qtr 12/18/2019 <1.0 117 <1.0 <1.0 48.8 1....86 ,. 1st Qtr 3/18/2020 <1.0 93.7 <1.0 <1.0 45.3 .2.44
2nd Qtr 6/10/2020 <1.0 90.1 <1.0 <1.0 48.9 3.26
3rd Qtr 9/18/2020 <1.0 84,9 <1.0 <1,0 51.0 3.58
4th Qtr 11/11/2020 <1.0 60.6 «1.0 «1.0 51.5 3.71
DWMRC split sample <10 68 <20 <20 54 0 12 H
Shaded indicates concentrations exceeding GWQS. H = Sample was analyzed beyond holchng times and may not be accureate concentrat on.
TABLE 1 (30 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020
Chloroform Contamination Investigation
DUSA White Mesa Mill
7W4-34 Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride
(5 pg/L)
Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Chloride No GWQS (mg/L)
Nitrate, Nitrate -i- Nitrite
(10 mg/L)
4th Qtr 11/14/2013 0 ,<1 <1 0 <1 0 <1 0 19 2 1 64
1st Qtr 1/23/2014 <1 0 <1 0 <1 0 <1 0 20 4 1 93
2nd Qtr 5/22/2014 <1 0 <1 0 <1 0 <1 0 17 9 1 69
3rd Qtr 8/13/2014 <1 0 <1 0 <1 0 <1 0 18 1 10
41h Qtr 10/29/2014 0 .<1 <1 0 <1 0 <1 0 17 8 1 16
1st Qtr 3/11/2015 <1 0 <1 0 <1 0 <1 0 17 7 1 21
2nd Qtr 6/11/2015 <1 0 <1 0 <1 0 <1 0 17 4 0 868
3rd Qtr 9/3/2015 <1 0 <1 0 <1 0 <1 0 15 1 0 458
4th Qtr 10/21/2015 51 0 ........ <1 0 <1 0 <1 0 15 8 0 368
1st Qtr 3/16/2016 <To <1 o <1 o <1 0 17 3 0-62E
2nd Qtr 5/25/2016 <1 0 <1 0 <1 0 <1 0 18 0 605
3rd Qtr 8/3/2016 <1 0 <1 0 <1 0 <1 0 17 2 0 726
4th Qtr 10/20/2016 <1 0 <1.0 <1 0 <1 0 19 0 612
1st Qtr 3/15/2017 <1 0 <1 0 <1 0 <1 0 18 0 0 674
2nd Qtr 6/15/2017 <1 0 <1 0 <1 0 <1 0 15 7 0 727
3rd Qtr 8/2/2017 <1 0 <1 0 <1 0 <1 0 19 8 0 733
4th Qtr 10/10/2017 <1 0 <1 0 <1 0 <1 0 18 5 0 774
Duplicate TW4-65 <1 0 • <1 0 - <1 0 <1 0_ 20 4 0 784
1st Qtr 3/14/2018 <1 0 <1 0 <1 0 <1 0 19 1 0 737
2nd Qtr 6/13/2018 <1 0 <1 0 <1 0 <1 0 19 5 0 877
3rd Qtr 8/29/2018 <1 0 <1 0 <1 0 <1 0 23 8 0 736
4th Qtr 12/12/2018 <1 0 • <1,0 <1 0 <1 0 18 5 0 889
1st Qtr 3/16/2019 <1 0 <1 0 <1 0 <1 0 17 9 0 859
2nd Qtr 6/13/2019 <1 0 <1 0 <1 0 <1 0 20 1 0 994
3rd Qtr 9/11/2019 <1 0 <1 0 <1 0 <1 0 17 8 0 934
4th Qtr 12/14/2019 <1 0 <1 0 <1 0 <1 0 21 4 1 07
1st Qtr 3/17/2020 <1 0 <1 0 <1 0 <1 0 20 1 1 090
2nd Qtr 6/10/2020 <1 0 <1 0 <1 0 <1 0 20 9 1 240
3rd Qtr 9/17/2020 <1 0 <1 0 <1 0 <1 0 19 0 0 978
41h Qtr 11/4/2020 <1 0 <1 0 <1 0 <1 0 18 7 1 04
• TW4-35
3rd Qtr 8/27/2014 <1 0 <1 0 <1 0 <1 0 34 0 2
4th Qtr 10/28/2014 0 .<1 <1 0 <1 0 <1 0 34 1 0 351
1st Qtr 3/11/2015 <1 0 <1 0 <1 0 <1 0 34 9 0 436
2nd Qtr 6/10/2015 <1 0 <1 0 <1 0 <1 0 35 2 0 452
3rd Qtr 9/3/2015 <1 0 <1 0 <1 0 <1 0 35 9 0 304
4th Qtr 10/28/2015 «10 _ <1 0 <1 0 <1 0 33 4 0 419
1st Qtr 3/16/2016 <-i 0 <1 0 <1 0 <1 0 35 T 0 521
2nd Qtr 5/26/2016 <1 0 <1 0 <1 0 <1 0 35 4 0 631
3rd Qtr 8/3/2016 <1 0 <1 0 <1 0 <1 0 34 8 0 723
41h Qtr 10/20/2016 <1 0 <1 0 <1 0_ <1 0 37 1 0 626
1st Qtr 3/15/2017 <1 0 <1 0 <1 6 <1 0 33 7 0 673
2nd Qtr 6/15/2017 <1 0 <1 0 <1 0 <1 0 34 8 0 699
3rd Qtr 8/2/2017 <1 0 <1 0 <1 0 <1 0 36 3 0 670
4th Qtr 10/10/2017 <1 0 - • <1 0 <1 0 <1 0 31 7 q 651
1st Qtr 3/14/2018 <1 0 <1 0 <1 0 <1 0 37 4 0 740
2nd Qtr 6/13/2018 <1 0 <1 0 <1 0 <1 0 33 7 0 662
3rd Qtr 8/30/2018 <1 0 <1 0 <1 0 <1 0 39 3 0 527
4th Qtr 12/12/2018 «1 0 <1 0 <1 0 <1 0 43 0 q 559
1st Qtr 3/16/2019 • <1 0 <1 0 <1 0 <1 0 33 5 0 574
2nd Qtr 6/13/2019 <1 0 <1 0 <1 0 <1 0 35 5 0 670
3rd Qtr 9/11/2019 <1 0 <1 0 <1 0 <1 0 31 7 0 525
41h Qtr 12/14/2019 0 .<1 • <1 0 <1 0 <1 0 37 4 0 524
1st Qtr 3/17/2020 <1 0 <1 0 <1 0 <1 0 34 5 0 59.8
2nd Qtr 6/11/2020 <1 0 <1 0 <1 0 <1 0 34 0 0 699
3rd Qtr 9/17/2020 <1 0 <1 0 <1 0 <1 0 32 2 0 760
41h Qtr 11/4/2020 <1 0 <1 0 <1 0 <1 0 30 4 0 756
TW4-36
3rd Qtr 8/27/2014 <1 0 <1 0 <1 0 <1 0 65 <0 1
4th Qtr 10/23/2014 <1 0 • <1 0 <1 0 <1 0 67 3 <0 1
lii Qtr 3/11/2015 <1 0 <1 0 <1 0 <1 0 67 2 <0 1
2nd Qtr 6/10/2015 <1 0 <1 0 <1 0 <1 0 69 3 <0 1
3rd Qtr 9/3/2015 <1 0 <1 0 <1 0 <1 0 76 4 <0 1
4th Qtr 10/21/2015 <1 0 <1 0 <1 0 <1 0 64 5_ <0 1
1st Qtr 3/11/2016 <1 0 <1 0 <1 0 <1 0 67 2 <0 1
2nd Qtr 5/26/2016 <1 0 <1 0 <1 0 <1 0 72 3 <0 1
3rd Qtr 7/28/2016 <1 0 <1 0 <1 0 <1 0 69 4 <0 1
4th Qtr 10/20/2016 <1 0 <1 0 <1 0 <1 0 73 8 <0 1
Duplicate TW4-70 <1 0 <1 0 <1 0 <1 0 72 <0 1
1st Qtr 3/15/2017 <1 0 <1 0 <1 0 <1 0 60 2 <0 1
2nd Qtr 6/15/2017 <1 0 <1 0 <1 0 <1 0 71 3 <0 1
3rd Qtr 8/2/2017 <1 0 <1 0 <1 0 <1 0 69 6 <0 1
4th Qtr 10/10/2017 <1 0 • <1 0 <1 0 <1 0 62 9 0 104
1st Qtr 3/14/2018 <1 0 <1 0 <1 0 <1 0 73 8 <0 1
2nd Qtr 6/12/2018 <1 0 <1 0 <1 0 <1 0 64 3 <0 1
3rd Qtr 8/29/2018 <1 0 <1 0 <1 0 <1 0 76 4 <0 1
41h Qtr 12/12/2018 <1 0 <1 0 <1 0 <1 0 65 8 0 123
1st Qtr 3/16/2019 <1 0 <1 0 <1 0 <1 0 65 0 116
2nd Qtr 6/13/2019 <1 0 <1 0 <1 0 <1 0 71 5 <0 1
3rd Qtr 9/11/2019 <1 0 <1 0 <1 0 <1 0 69 6 <0 1
4th Qtr 12/14/2019 0 .<1 • <1 0 <1 0 <1 0 73 7 <0 1
1st Qtr 3/17/2020 <1 0 <1 0 <1 0 <1 0 69 1 <0 1
2nd Qtr 6/11/2020 <1 0 <1 0 <1 0 <1 0 67 0 <0 1
3rd Qtr 9/17/2020 <1 0 <1 0 <1 0 <1 0 66 0 <0 1
41h Qtr 11/4/2020 <1 0 <1 0 <1 0 <1 0 64 0 <0 1
Shaded indicates concentrations exceeding GWQS
TABLE 1 (31 of 31)
Historic Summary Of Monitoring Well Analytical Results Up To The 4th Qarter 2020 Chloroform Contamination Investigation
DUSA White Mesa Mill
TW4-37 (chloroform pumping well 6/9/15) Sampling Event
Parameter
(GWQS)
Carbon Tetrachloride (5 pg/L) Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L)
Chloride
No GWQS (mg/L)
Nitrate, Nitrate .i. Nitrite
(10 mg/L)
2nd Qtr 6/8/2015 18.2 30,200 15.7 1.94 345 35.2
3rd Qtr 9/3/2015 16.6 19,100 13.7 1.04 374 32.4
4th Qtr 10/19/2015 12.5 19,500, 9 38 1 17 399 34.6
1st Qtr 3/9/2016 15.8 17,500 3.57 1.34 332 28.4
2nd Qtr 5/23/2016 14.4 16,200 3.57 1.17 389 27.9
3rd Qtr 7/25/2016 16.7 15,900 <1.0 <1.0 294 33.4
415 Qtr 10/12/2016 16.3 1.6400 <1.0 <1.0 304 26.1
1st Qtr 3/8/2017 15.4 18,000 3.57 1.34 305 32.3
2nd Qtr 6/15/2017 16.2 15,800 <1.0 <1.0 281 31.2
3rd Qtr 7/26/2017 15.1 15,000 <1.0 <1.0 277 30.5
41h Qtr 10/11/2017 12.6 15 500 2.47 <1.0 255
1st Qtr 3/12/2018 12.8 12,900 1.14 <1.0 263 - ......N.i. 30.6
2nd Qtr 6/8/2018 , 10.6 14,400 <1.0 <1.0 275 28.6
3rd Qtr 8/22/2018 12.1 14,100 6.2 <1.0 387 25.3
4....t cp.r.... 114812.01.8 „ 11.3 15 200 19.8 <1.0 264 27.3 .1st.Qtr - - 3/8/2019 - 13.8 13,300 1.24 <1.0 209 30.1
2nd Qtr 6/5/2019 14.6 16,200 <1.0 <1.0 250 31.2
3rd Qtr 9/4/2019 10.7 11,900 1.9 <1.0 228 25.8
4th Qtr 12/10/2019 8.81 13 100 3.12 <1.0 220 25.5
1st Qtr 2/19/2020 8.53 12,000 12.3 <1.0 236 28.3
2nd Qtr 5/27/2020 11.8 11,700 1.44 <1.00 321 28.3
3rd Qtr 9/4/2020 9.62 13,800 <1.0 <1.0 273 29.5
4t5 Qtr 10/28/2020 6.52 10,300 29.4 <1.0 254 28.7
TW4-38
4th Qtr 11/10/2016 <1.0 <1.0 <1 0 <1.0 40 112
1st Qtr 3/15/2017 <1.0 <1.0 <1 0 <1.0 35.7 ... ... -.jai
2nd Qtr 6/15/2017 <1.0 <1.0 <1.0 <1.0 36.2 10.8
3rd Qtr 8/2/2017 <1.0 <1.0 <1.0 <1.0 36.9 10.1
4th_Qtr_.... 10/10/2017 .510_ <1.0 <1.0 <1.0 3-1.3 10.3
1 st ai 3/14/2018 <1.0 _ <1.0 <1.0 <1.0 36.5 9.34
2nd Qtr 6/13/2018 <1.0 <1.0 <1.0 <1.0 33.1 9.48
3rd Qtr 8/30/2018 <1.0 <1.0 <1.0 <1.0 39.2 7.77
41h Qtr 12/12/2018 <1.0 <1.0 <1.0 <1.0 .5.,.,9 ....E.129. 1st Qtr 3/16/2019 <1.0 <1.0 <1.0 <1.0 33.5. 6.96
2nd Qtr 6/13/2019 <1.0 <1.0 <1.0 <1.0 33.7 8.53
Duplicate TW4-70 <1.0 <1.0 <1.0 <1.0 35.3 9.52
3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 31.6 7.61
415 Qtr 12114/2019 <1.0 <1.0 <1.0 <1.0 36 7.51
1st Qtr 3/17/2020 <1.0 <1.0 <1.0 <1.0 33.4 8.11
2nd Qtr 6/11/2020 <1.0 <1.0 <1.0 <1.0 34.9 9.00
3rd Qtr 9/18/2020 <1.0 <1.0 <1.0 01.0 34.7 7.35
4th Qtr 11/4/2020 <1.0 <1.0 <1.0 <1.0 35.1 7.72
1'W4-39(chloroforrn pun*, moll mrzois) 415 Qtr 11/11/2016 <1.0 2,800 <1.0 01.0 68.9 20.7
1st Qtr 3/8/2017 8,15 6,460 <1.0 1.35 130 6.44
2nd Qtr 6/15/2017 . 82 5,560 <1.0 1.31 120 6.25
3rd Qtr 7/26/2017 14.4 10,000 <1.0 1.5 132 7.74
4th Qtr 10/10/2017 <1.0 552 <1.0 <1.0 73.5 ..2.:6 1st Qtr 3/12/2018 3.1 2,870 <1.0 <1.0 118 3.93
2nd Qtr 6/8/2018 7.94 7,160 <1.0 <1.0 107 4.84
3rd Qtr 8/2212018 12.5 8,180 2.33 <1.0 110 6.05
41h Qtr 11/28/2018 6.08 8,520 2.33 <1.0 123 6.39
1st Qtr 3/8/2019 1.2 885 <1.0 <1.0 49 2.08
2nd Qtr 6/5/2019 11.6 8,640 <1.0 <1.0 114 8.45 3rd Qtr 9/4/2019 5.71 4,240 <1.0 <1.0 48.2 1.75
12/10/2019 1.14 1§§.0 <1.0 <1.0 74.7 0.95 41 tsht QQttrr 2/19/2020 <1a 812 <1.0 <1.0 76.5 0.792
2nd Qtr 5/27/2020 7.56 5,870 <1.0 <1.0 , 88.5 5.010
3rd Qtr 9/18/2020 8.18 5,960 <1.0 <1.0 63.21 2.69 415 Qtr 10/28/2020 <1.0 648 1.19 <1.0 83.2 7.03
TIN4-40,,m punipIng MI 5/2015)
1st Qtr 3/21/2018 <1.0 248 <1.0 <1.0 35.7 3.08
2nd Qtr 6/13/2018 <1.0 131 <1.0 <1.0 31.6 3.33
3rd Qtr 9/5/2018 <1.0 116 <1.0 <1.0 37.6 3.22
41h Qtr 12/12J2018 <1.0 118 <1.0 <1.0 29.9 3.54
Duplicate TW475 <1.0 119 <1.0 <1..0 32.3 3.18 (2)1st Qtr 3/20/2019 <1.0 111 <1.0 <1.0 30.9 3.18
2nd Qtr 6/5/2019 <1.0 263 <1.0 <1.0 35.6 3.55
3rd Qtr 9/4/2019 <1.0 380 <1.0 <1.0 35.9 339
41h Qtr 12/10/2019 <1,0 314 <1.0 <1.0 36.7 ...2.9 1st Qtr 2/19/2020 <1.0 364 <1.0 <1.0 38.5 2.08
2nd Qtr 5/27/2020 <1.0 367 <1.0 <1.0 36.5 2.91
3rd Qtr 9/4/2020 <1.0 333 <1.0 <1.0 34.2 2.88
4th Qtr 10/28/2020 <1.0 264 <1.0 <1.0 34.6 2.58
1W4-411.1orolonn pumping well 5/2018) 2nd Qtr 5/8/2018 <1.0 1,400 <1.0 <1.0 42E1 6.54
3rd Qtr 8/22/2018 <1.0 1,390 <1.0 <1.0 45.5 6.13
4th Qtr 11/28/2018 <1.0 1320 <1.0 <1.0 41.4 6.02
1st Qtr 3/8/2019 <1.0 1,220 <1.0 <1.0 39.1 6.71
2nd Qtr 6/5/2019 <1.0 1,320 <1.0 <1.0 38.1 6.00
3rd Qtr 9/4/2019 , <1.0 1,190 <1.0 <1.0 39.4 6.22
4th Qtr 12/10/2019 <1.0 1110 <1.0 <1.0 42.1 a 11
1st Qtr 2/19/2020 <1.0 1,200 <1.0 <1.0 44.4 6.12
2nd Qtr 5/27/2020 <1.0 1,220 <1.0 <1.0 41.7 6.78
3rd Qtr 9/4/2020 <1.0 1,110 <1.0 <1.0 40.2 6.69
4t5 Qtr 10/28/2020 <1.0 1,020 <1.0 <1.0 39.7 6.25
TW4-42
2nd Qtr 6/19/2019 <1.0 <1.0 <1.0 <1.0 23.3 2.57
3rd Qtr 9/11/2019 <1.0 <1.0 <1.0 <1.0 20.6 2.75
4th Qtr 12/10/2019 <1.0 <1.0 <1.0 <1.0 22.6 2.82
kieliSgitlAllt , 5_141., <1,0 . <1 0 _ <1 0 22.6 ---- ..... ---____ 2 95
1st Qtr -2/17/2020 <1.0 <1.0 <1.0 <1.0 23.2 2.88
2nd Qtr 6/10/2020 <1.0 <1.0 <1.0 <1.0 23.2 2.88 3rd Qtr 9/17/2020 <1.0 <1.0 <1.0 <1.0 23.5 3.65 4t5 Qtr 11/4/2020 <1.0 <1.0 <1.0 <1.0 22 4 2.77
Shaded indicates concentrations exceeding GWQS. (1) VOCs were resampled because laboratory missed holding time. 2) Chloroform aimi5 well stated in May 2019.
Table 2
Summary of EFR QA/QC Samples
4th Quarter 2020
Duplicate Samples of Wells
Parameter GWQS Duplicate of MW-32 Duplicate of TW4-8 Duplicate of TW4-16
MW-32 TW4-65 RPD TW4-8 TW4-70 RPD MW-16 TW4-75 RPD
Chloride none 31.3 35.9 -13.7 54.7 49.9 9.2 85.9 85.6 0.3
Nitrate + Nitrite (as N) 10 mg/L <0.1 <0.1 nc 1.27 1.27 0.0 5.73 5.74 -0.2
Chloroform 70 pg/L <1.0 <1.0 nc 51.3 52.9 -3.1 270 277 -2.6
Carbon tetrachloride 5 pg/L <1.0 <1.0 nc <1.0 <1.0 nc <1.0 <1.0 nc
Chloromethane 30 pg/L <1.0 <1.0 nc <1.0 <1.0 nc <1.0 <1.0 nc
Methylene Chloride 5 ug/L <1.0 <1.0 nc <1.0 <1.0 nc <1.0 <1.0 nc
nc = not calculated
Summary of DWMRC QA/QC Samples
Duplicate Samples of Wells
Parameter GWQS Duplicate of TW4-9
TW4-9 TW4-81 RPD
Chloride none 38.0 38.0 0.0
Nitrate + Nitrite (as N) 10 mg/L 0.97 0.97 0.0
Chloroform 70 pg/L 48 46 4.3
Carbon tetrachloride 5 pg/L <1.0 <1.0 nc
Chloromethane 30 pg/L <1.0 <1.0 nc
Methylene Chloride 5 uo/L <1.0 <1.0 nc
nc = not calculated
Table 3
Summary of Comparing DWMRC and EFR Split Samples
4th Quarter 2020
Parameter GWQS DWMRC EFR
RPD
DWMRC EFR RPD DWMRC EFR RPD
TW4-7 TW4-7 TW4-8 TW4-8 TW4-70 for TW4-8 for TW4-70 TW4-9 (1)TW4-81 TW4-9 for TW4-9 for TW4-81
Chloride none 43 42.8 0.5 56 54.7 49.9 2.3 11.5 38 38 37.2 2.1 2.1
Nitrate + Nitrite (as N) 10 mg/L 3.9 4.4 -12.0 0.16 1.27 1.27 -155 -155 0.97 0.97 1.11 -13.5 -13.5
Chloroform 70 pg/L 930 967 -3.9 50 51.3 52.9 -2.6 -5.6 48 46 47.1 1.9 -2.4
Carbon tetrachloride 5 pg/L <10 <1.0 nc <10 <1.0 <1.0 nc nc <10 <1.0 <1.0 nc nc
Chloromethane 30 pg/L <20 <1.0 nc <20 <1.0 <1.0 nc nc <20 <1.0 <1.0 nc nc
Methylene Chloride 5 pg/L <20 <1.0 nc <20 <1.0 <1.0 nc nc <20 <1.0 <1.0 nc nc
Parameter GWQS DWMRC EFR RPD DWMRC EFR
RPD TW4-16 TW4-16 TW4-75 for TW4-16 for TW4-75 TW4-18 TW4-18
Chloride none 87 85.9 85.6 1.3 1.6 41 39.6 3.5
Nitrate + Nitrite (as N) 10 mg/L 0.37 5.73 5.7 -176 -176 3.3 3.67 -10.6
Chloroform 70 pg/L 290 270 277.0 7.1 4.6 56 58.6 -4.5
Carbon tetrachloride 5 pg/L <10 <1.0 <1.0 nc nc <10 <1.0 nc
Chloromethane 30 pg/L <20 <1.0 <1.0 nc nc <20 <1.0 nc
Methylene Chloride 5 pg/L <20 <1.0 <1.0 nc nc <20 <1.0 nc
Parameter GWQS DWMRC EFR
RPD
DWMRC EFR
RPD
DWMRC EFR
RPD TW4-29 TW4-29 TW4-30 TW4-30 TW4-33 TW4-33
Chloride none 42 40.8 2.9 39 37.1 5.0 54 51.5 4.7
Nitrate + Nitrite (as N) 10 mg/L 0.75 3.27 -125 <0.5 3.64 >30% 0.12 3.71 -187
Chloroform 70 pg/L 670 671 -0.1 66 82.8 -22.6 68 80.6 -17.0
Carbon tetrachloride 5 pg/L <10 <1.0 nc <10 <1.0 nc <10 <1.0 nc
Chloromethane 30 pg/L <20 <1.0 nc <20 <1.0 nc <20 <1.0 nc
Methylene Chloride 5 pg/L <20 <1.0 nc <20 <1.0 nc <20 <1.0 nc
(1) TW4-81 is a duplica e sample for TW4-9.
RPD exceeding 30% for DRC comparing their duplicate sample with EFR sample
nc: not calculated
Tabel 4
Chloroform Mass Removal Calculations for the 4th Qurater 2020
EFR White Mesa Mill, Bland, Utah
Well ID MW4 MW-26 TW4-1 TW4-2 TW4-4 TW4-11 TW4-19 TW4-21 TW4-22 TW4-24 TW4-25 TW4-37 TW4-39 TW4-40 TW4-41
(1)Chloroform (ug/L) 1,050 866 924 1,130 979 2,670 660 948 3,640 72.6 0.0 10,300 648 264 1,020
Chloroform (g/L) 1.05E-03 8.66E-04 9.24E-04 1.13E-03 9.79E-04 2.67E-03 6.60E-04 9.48E-04 3.64E-03 7.26E-05 0.00E+00 1.03E-02 6.48E-04 2.64E-04 1.02E-03
Chloroform (lbs/L) 2.32E-06 1.91E-06 2.04E-06 2.50E-06 2.16E-06 5.90E-06 1.46E-06 2.09E-06 8.04E-06 1.60E-07 0.00E+00 2.28E-05 1.43E-06 5.83E-07 2.25E-06
Chloroform (lbs/gal) 8.78E-06 7.24E-06 7.73E-06 9.45E-06 8.19E-06 2.23E-05 5.52E-06 7.93E-06 3.04E-05 6.07E-07 0.00E+00 8.61E-05 5.42E-06 2.21E-06 8.53E-06
Total gallons pumped 91258.6 28934.5 9318.7 14582.9 15061.5 1394.6 144512.0 107061.2 22866.1 103987.2 86254.4 61323.9 46794.2 77535.9 17765.7
lbs of chloroform removed 0.8 0.2 0.07 0.14 0.1 0.03 0.8 0.8 0.7 0.063 0.00 5.3 0.3 0.17 0.2
Gallons of chloroform removed 0.07 0.02 0.01 0.01 0.01 0.00 0.06 0.07 0.06 0.005 0.00 0.43 0.02 0.01 0.01
total lbs of chloroform removed 9.6
total gallons of chloroform removed 0.8
1) Assuming that the chloroform concentration result for the quarter monitoring event is the average chloroform concentration for the entire quarter. Chloroform Pumping Wells
Nitrate Pumping Wells AB = Abandonded Well