6019_MecklenburgFoxHole_GWMR_DIN27956_20160504

May 2016 Semi-Annual Monitoring Report
Foxhole Landfill - Permit # 60-19
Charlotte, North Carolina
S&ME Project No. 1356-07-003
Prepared for:
Mecklenburg County LUESA
700 North Tryon Street
Charlotte, North Carolina 28202
Prepared by:
S&ME, Inc.
9751 Southern Pine Boulevard
Charlotte, NC 28273
August 1, 2016
S&ME, Inc. | 9751 Southern Pine Boulevard | Charlotte, NC 28273 | p 704.523.4726 | f 704.525.3953 | www.smeinc.com
August 1, 2016
Mecklenburg County LUESA
700 North Tryon Street
Charlotte, North Carolina 28202
Attention:Amber Grzymski
Reference:May 2016 Semi-Annual Monitoring Report
Foxhole Landfill - Permit # 60-19
Charlotte, North Carolina
S&ME Project No. 1356-07-003
Dear Ms. Grzymski:
S&ME Inc. (S&ME) has completed the May 2016 Semi-Annual Monitoring and Reporting for Mecklenburg
County’s Foxhole Landfill. This report presents the results of the first monitoring event of the year for the
facility.
S&ME appreciates the continued opportunity to provide services to you and Mecklenburg County. If you
have any questions or need additional information regarding this report, please contact Ed Henriques at
[phone].
Sincerely,
S&ME, Inc.
Amanda Bloom Edmund Q.B. Henriques, L.G.
Staff Professional Project Manager/Senior Geologist
NC Geology License No. C-145
cc: Jaclynne Drummond, NCDENR – Solid Waste Section
May 2016 Semi-Annual Monitoring Report
Foxhole Landfill - Permit # 60-19
Charlotte, North Carolina
S&ME Project No. 1356-07-003
August 1, 2016 ii
Table of Contents
1.0 Introduction............................................................................................................1
2.0 Groundwater Levels and Flow............................................................................1
3.0 Analytical Data ......................................................................................................1
3.1 Monitoring Well Sampling..............................................................................................2
3.1.1 Volatile Organic Compounds..............................................................................................2
3.1.2 Metals..................................................................................................................................2
3.2 Surface Water Sampling..................................................................................................2
3.2.1 Volatile Organic Compounds..............................................................................................2
3.2.2 Metals..................................................................................................................................3
4.0 Statistical Analysis................................................................................................3
Appendices
Appendix I – Drawings
Appendix II – Tables
Appendix III – Well Sampling Logs and Laboratory Reports
Appendix IV – Statistical Analysis Procedure Sheets
May 2016 Semi-Annual Monitoring Report
Foxhole Landfill - Permit # 60-19
Charlotte, North Carolina
S&ME Project No. 1356-07-003
August 1, 2016 1
1.0 Introduction
S&ME, Inc. (S&ME) was contracted by Mecklenburg County to provide groundwater and surface water
monitoring services at the Highway 521 Landfill “Foxhole” located at 17131 Lancaster Highway in
Charlotte, North Carolina. This monitoring event was conducted on May 4 and 5, 2016.
This report presents the results of the first monitoring event for the year 2016 at the facility, which
included the sampling of one (1) background groundwater monitoring well (MW-1R), ten (10) compliance
groundwater monitoring wells (MW-2R, MW-3, MW-7, MW-8, MW-10, MW-10A, MW-11, MW-11A, MW-
12, and MW-13), and two (2) surface water locations (SW-1 and SW-2). Please note that five (5)
compliance wells (MW-4, MW-5, MW-6, MW-6A and MW-9) were abandoned in 2011 and 2012 as part of
the Phase 2 landfill expansion. The next monitoring event is scheduled for November 2016.
2.0 Groundwater Levels and Flow
The water table elevations and our interpretation of the groundwater surface expressed as a
potentiometric map along with groundwater flow direction are shown on Drawing 1 of 1 located in
Appendix I – Drawings. Based upon the groundwater elevations in the vicinity of the landfill,
groundwater in this area is projected to flow from west to east toward Two-Mile Creek. Groundwater
levels obtained during the May 2016 monitoring event, as well as monitoring well construction data, are
presented in Table 1 located in Appendix II – Tables.
The hydraulic gradient (i) in the vicinity of each well was estimated by calculating the vertical difference
between the groundwater elevation at each well and one or more nearby contour lines from Drawing 1
of 1 - Groundwater Surface Map. This value was then divided by the horizontal distance measured from
the well to the selected groundwater elevation contour line. Groundwater velocity was calculated by
multiplying the gradient (i) by the hydraulic conductivity (k) and dividing by the estimated effective
porosity (ne) of the aquifer.Table 2 in Appendix II summarizes the groundwater flow rates for the
monitoring wells.
3.0 Analytical Data
Analytical results for the landfill monitoring wells are summarized in Table 4 in Appendix II. Groundwater
detections at or above the 15A NCAC 2L .0202 Groundwater Standards (2L Standards) and/or Solid Waste
Groundwater Protection Standards (SW GWP Standards) are highlighted in gray. Field measurements of
pH, conductivity, and temperature are summarized in Table 3 in Appendix II. Well sampling logs
containing this information are included in Appendix III. Analytical results for the surface water
sampling locations are summarized in Table 5 in Appendix II. Surface water detections at or above the
15A NCAC 2B Freshwater Standards (2B Standards) are highlighted in gray. The monitoring wells and
surface water locations were sampled for Appendix I volatile organic compounds and metals.
May 2016 Semi-Annual Monitoring Report
Foxhole Landfill - Permit # 60-19
Charlotte, North Carolina
S&ME Project No. 1356-07-003
August 1, 2016 2
3.1 Monitoring Well Sampling
3.1.1 Volatile Organic Compounds
Chloroform was detected in groundwater monitoring well MW-7 at a concentration of 2.7 J micrograms
per liter (ug/L), which is less than the 2L Standard of 70 µg/L. Due to the proximity of monitoring well
MW-7 to a sewer line, it is likely that the detection of chloroform is not from a release from the landfill,
but from the adjacent sewer line.
3.1.2 Metals
One or more inorganic constituents (metals) were detected in each of the groundwater monitoring wells
sampled. Concentrations of antimony, barium, beryllium, copper, nickel, and zinc were detected at
concentrations less than their respective 2L Standard and SW GWP Standard.
Chromium was detected at a 23.0 µg/L in compliance monitoring well MW-10A, a concentration greater
than its respective 2L Standard of 10 µg/L.
Cobalt was detected at above its respective SW GWP Standard of 1 µg/L in compliance groundwater
monitoring wells MW-2R and MW-10 at concentrations of 5.09 J µg/L and 1.22 J µg/L, respectively. It is
important to point out that cobalt was also detected in background well MW-1R at a concentration of
1.22 J µg/L, which also exceeds the published SW GPS Standard of 1 µg/L. Cobalt has generally been
detected in this background well since monitoring commenced in 1999.
Vanadium was at concentrations greater than its respective GWP ST standard of 0.3 µg/L in compliance
groundwater monitoring wells MW-3, MW-10, MW-10A, MW-11A, MW-12, and MW-13 at concentrations
ranging from 1.94 J to 17.0 J µg/L. It is important to point out that vanadium was also detected in
background well MW-1R at a concentration of 5.56 J µg/L, which is greater than the published SW GPS
Standard of 0.3 µg/L. Vanadium has been detected frequently in this background well since monitoring
commenced in 1999.
The metals detected in the monitoring wells during the May 2016 monitoring event are summarized in
Table 4 in Appendix II. Based on previous metals concentrations in the background groundwater
monitoring well MW-1/1R, it appears that the metals concentrations are from naturally occurring
dissolved metals extracted from suspended solids (silts and clays) collected during sample extraction
rather than an anthropogenic source.
3.2 Surface Water Sampling
3.2.1 Volatile Organic Compounds
No volatile organic compounds were detected in the surface water samples during the May 2016
sampling event.
May 2016 Semi-Annual Monitoring Report
Foxhole Landfill - Permit # 60-19
Charlotte, North Carolina
S&ME Project No. 1356-07-003
August 1, 2016 3
3.2.2 Metals
Two or more inorganic constituents (metals) were detected in the surface water samples. Concentrations
of barium, chromium, vanadium, and zinc were detected in both surface water samples at concentrations
below their respective 2B Standard. Copper was detected in both surface water samples at
concentratio7ns that appear to be greater than the 2B Standards. Based on the groundwater analytical
results for compliance wells, these detections of copper are not thought to be related to a release from
the facility’s landfill unit.
4.0 Statistical Analysis
S&ME compared the water quality data with the 2L Standards and the SW GWP standards and performed
a statistical evaluation of the data. S&ME utilized three statistical methods to evaluate statistically
significant increases between the compliance monitoring wells and the background monitoring well (MW-
1/1R).
The first method utilized was a one-way parametric Analysis of Variance (Parametric ANOVA). The
parametric ANOVA analysis is recommended by the 1992 guidance document for parameters with fewer
than 15% non-detects in a specific well.
The second method used was the Kruskal-Wallis non-parametric rank method. The Kruskal-Wallis
method is recommended by the 1992 guidance document for parameters that have 15% to 90% non-
detects in a specific well.
The third method used was an inter-well non-parametric prediction limit. The prediction limit was used for
parameters with greater than 90% non-detects in a specific well. The 1992 guidance document
recommends this method when a significant portion of the samples are non-detect.
Table 6 in Appendix II summarizes the results of the statistical analysis. Please note that Chloroform
showed a statistical increase over background in compliance monitoring well MW-7. As discussed above
in Section 3.1.1, detections of Chloroform in monitoring well MW-7 are likely due to MW-7’s proximity to
an adjacent sewer line and not a release from the landfill. Copies of the analytical procedures used to
perform the analysis used by the ChemStat software are included in Appendix IV.
It is important to point out that time vs concentrations charts for concentrations of vanadium in wells
MW-3, MW-10, MW-10A, MW-11A, MW-12, and MW-13 in MW-10A generally depict stable or declining
concentrations over time. These observations are further supported by Mann-Kendall trend analyses
indicating no evidence of an upward trend for vanadium concentrations over time in these wells. The
historical concentrations of vanadium in MW-10A are likely indicative of turbidity in the well. The majority
of the wells on site have historically had detections of vanadium above the published 2L standard
concentration, including background monitoring well MW-1R.
Time vs concentrations charts for cobalt in wells MW-2R and MW-10 generally depict stable or declining
concentrations over time, which is further supported by Mann-Kendall trend analyses indicating no
evidence of an upward trend in these wells.
May 2016 Semi-Annual Monitoring Report
Foxhole Landfill - Permit # 60-19
Charlotte, North Carolina
S&ME Project No. 1356-07-003
August 1, 2016 4
Mann-Kendall trend analysis of chromium in MW-10, indicated evidence of an upward trend. The historic
concentrations of chromium in well MW-10 exhibit noteworthy variability, likely related to differences in
turbidity in the well during sample collection. It is noted that the 2L Standards do not apply to sediment
or other particulate matter preserved in groundwater samples as a result of groundwater sample
collection procedures or well construction issues.
The presence of cobalt and vanadium in the background well coupled with no evidence of upward trends
for these constituents provides evidence of their natural occurrence in the facility’s groundwater. 15A
NCAC 02L .0202 contains a provision for instances where a naturally occurring substances exceed the
published standards, such that standard shall be the naturally occurring concentration.
Appendices
Appendix I – Drawings
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DRAWN BY:
CHECKED BY:DRAWING NUMBER:WWW.SMEINC.COM
3201 SPRING FOREST RD, RALEIGH, NC 27616
NC ENGINEER LICENSE #F-0176
1
BTR1356-07-003
JULY 20161" = 300'
FOXHOLE LANDFILL (PERMIT #60-19)
CHARLOTTE, NORTH CAROLINA
GROUNDWATER CONTOUR MAP - MAY 2016
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Appendix II – Tables
LATITUDE LONGITUDE GROUND TOH DTW - TOH GW ELEV.
(MM/DD/YY)(ft)(ft-MSL)
MW-1R 03/23/09 35.0164638° -080.8495912° 687.40 690.65 +3 .00 to 33.0 33.0 to 48.0 0.0 to 29.0 29.0 to 31.0 #2 31.0 to 48.0 SAP 32.47 658.18
MW-2R 02/16/10 35.0129978° -080.8487614° 660.90 663.80 +2.90 to 20.0 20.0 to 35.0 0.0 to 16.0 16.0 to 18.0 #2 18.0 to 35.0 SAP 28.67 635.13
MW-3 03/19/99 35.0162047° -080.8459443° 641.68 644.08 +2.25 to 10.0 10.0 to 25.0 0.0 to 5.0 5.0 to 8.0 #1 8.0 to 25.0 SAP 16.67 627.41
MW-7 03/16/99 35.0168592° -080.8441975° 634.81 637.90 +2.86 to 10.0 10.0 to 25.0 0.0 to 5.0 5.0 to 7.0 #1 7.0 to 25.0 SAP 21.90 616.00
MW-8 03/08/99 35.0160863° -080.8419354° 618.90 620.19 +2.35 to 10.0 10.0 to 25.0 0.0 to 5.0 5.0 to 8.0 #1 8.0 to 25.0 SAP 18.42 601.77
MW-10 04/02/99 35.0148756° -080.8403383° 624.23 627.03 +2.65 to 25.0 25.0 to 40.0 0.0 to 21.0 21.0 to 23.0 #1 23.0 to 40.0 SAP 31.72 595.31
MW-10A 03/31/99 35.0148756° -080.8403383° 624.30 627.32 +2.65 to 55.0 55.0 to 60.0 0.0 to 50.0 50.0 to 53.0 #1 53.0 to 60.0 SAP 32.25 595.07
MW-11 03/06/99 35.0133929° -080.8392855° 593.53 595.67 +1.47 to 7.0 7.0 to 22.0 0.0 to 3.0 3.0 to 5.0 #1 5.0 to 22.0 SAP 9.06 586.61
MW-11A 02/26/99 35.0133929° -080.8392855° 594.12 596.38 +1.62 to 40.0 40.0 to 45.0 0.0 to 36.0 36.0 to 38.0 #1 38.0 to 45.0 SAP 10.19 586.19
MW-12 10/02/12 35.0105705° -080.8450554° 633.10 636.07 +2.94 to 15.7 15.7 to 30.7 0.0 to 11.0 11.0 to 14.0 #2 14.0 to 31.2 SAP 18.62 617.45
MW-13 10/03/12 35.0122690° -080.8405290° 619.30 622.36 +3.04 to 23.0 23.0 to 38.0 0.0 to 18.0 18.0 to 21.0 #2 21.0 to 38.5 SAP 25.70 596.66
Notes:
(ft-MSL)Feet Mean Sea Level #1 Filter Sand Fine to Very Fine Grained Silica Sand
(ft-bls)Feet Below Land Surface Bentonite Bentonite Pellets
TOH Top of Hinge Sch. 40 Schedule 40 Pipe
Ground Ground Surface 0.010 Slot 0.010-Inch Machine-Slotted Pipe
DTW Depth to Water Neat Cement Cement Mixture without Bentonite
GW ELEV.Groundwater Elevation NA Not Available
#2 Filter Sand Medium to Fine Grained Silica Sand SAP Saprolite
The "A" suffix on the well locations indicates the deep well of the pair.
May 2016
2-INCH, SCH. 40, PVC 2-INCH, 0.010 SLOT, PVC NEAT CEMENT BENTONITE
(decimal degrees)(ft-MSL)(ft-bls)(ft-bls)(ft-bls)
SCREEN INTERVAL GROUT INTERVAL SEAL INTERVAL FILTER
PACK
SIZE
FILTER PACK
INTERVAL
GEOLOGY IN
SCREEN
INTERVAL(ft-bls)(ft-bls)
Table 1
Well Construction Summary and Water Level Data
Mecklenburg County Highway 521 Landfill - Foxhole
S&ME Project No: 1356-07-003
WELL ID
INSTALL
DATE
GPS COORDINATES SURVEY ELEVATIONS CASING INTERVAL
Table 2
May 2016 - Groundwater Flow Velocity
Mecklenburg County Highway 521 Landfill "Foxhole"
Permit # 60-19
S&ME Project No. 1356-07-003
Well
Identification
Hydraulic
Conductivity (K)
ft/yr
Effective
Porosity (n
e) %
Hydraulic
Gradient (i)
ft/ft
Seepage
Velocity (v)
ft/yr
6019 MW-1R 3.3E+02 0.15 0.030 66
6019 MW-2R 6.6E+02 0.13 0.030 152
6019 MW-3 3.6E+02 0.09 0.030 118
6019 MW-7 1.3E+03 0.20 0.030 192
6019 MW-8 1.6E+03 0.20 0.021 171
6019 MW-10 5.0E+02 0.23 0.014 31
6019 MW-11 1.9E+02 0.25 0.011 8
6019 MW-12 3.1E+02 0.27 0.014 16
6019 MW-13 2.8E+03 0.25 0.015 166
Notes:
(1) Hydraulic Conductivity was calculated from slug tests performed after well construction.
(2) Effective porosity was estimated from soils collected within the saturated portion of screen interval during
well construction
(3) Hydraulic gradient calculated by measuring linear feet between selected contour intervals.
(4) Seepage velocity v = (K*i)/n
e
Well ID DTW TOH (ft-bls) pH Temp (°C)
Conductanc
e (μS)
6019 MW-1R 32.47 5.93 17.8 61
6019 MW-2R 28.67 5.20 15.8 35
6019 MW-3 16.67 6.20 15.9 70
6019 MW-7 21.90 5.83 16.2 87
6019 MW-8 18.42 5.48 15.6 69
6019 MW-10 31.72 5.94 18.1 61
6019 MW-10A 32.25 10.84 17.8 202
6019 MW-11 9.06 5.52 16.2 290
6019 MW-11A 10.19 6.19 18.3 214
6019 MW-12 18.62 6.60 16.8 110
6019 MW-13 25.70 6.15 15.7 56
Notes:
(1) μS = microSiemens
(2) ft-bls = feet below land surface
(3) °C = degrees Celsius
Table 3
May 2016 - Field Parameters in Groundwater Monitoring Wells
Mecklenburg County Highway 521 Landfill "Foxhole"
Permit # 60-19
S&ME Project No. 1356-07-003
EPA Appendix I Volatile
Organic Compounds
Method 8260 (µg/L)
NCDEQ
SWSL
15A
NCAC
2L
Solid Waste
GWP ST
6019 MW-1R
6019
MW-2R
6019
MW-3
6019
MW-7
6019
MW-8
6019
MW-10
6019
MW-10A
6019
MW-11
6019
MW-11A
6019
MW-12
6019
MW-13
Chloroform 5 70 NE 2.7 J
EPA Appendix I Metals
Method 6010B/6020
(µg/L)
Antimony 6 NE 1 0.407 J 0.294 J 0.238 J 0.306 J
Barium 100 700 NE 81.7 J 65.7 J 35.6 J 16.5 J 18.6 J 40.4 J 9.71 J 52.0 J 24.3 J 25.9 J 56.6 J
Beryllium 1 NE 4 0.335 J 0.121 J 0.114 J
Chromium 10 10 NE 6.98 J 2.10 J 4.34 J 23.0 3.39 J 5.32 J 1.87 J
Cobalt 10 NE 1 1.22 J 5.09 J 3.41 J
Copper 10 1000 NE 4.18 J 18.7 2.05 J
Nickel 50 100 NE 14.8 J 3.65 J 2.28 J 3.60 J 4.09 J
Vanadium 25 NE 0.3 5.56 J 4.85 J 3.50 J 17.0 J 6.08 J 5.08 J 1.94 J
Zinc 10 1000 NE 16.0 10.5 5.43 J
Notes:
(1) µg/L = micrograms per liter (parts per billion)
(2) 15A NCAC 2L = North Carolina Groundwater Quality Standards
(3) GWP ST = Solid Waste Groundwater Protection Standard
(4) NE = No established standard
(5) J = Reported value is between method detection limit (MDL) and method reporting limit (MRL)
(6) B = Analyte was detected in associated laboratory method blank.
(7) Bold and highlighted indicates above 15A NCAC 2L or SW GWP standard
(8) Target analytes not shown were reported as below detection limits
(9) SWSL = North Carolina Department of Environmtental Quality (NCDEQ), Solid Waste Section Limit established in 2007
Table 4
May 2016 - Detected Analytes in Groundwater Monitoring Wells
Mecklenburg County Highway 521 Landfill "Foxhole"
Permit # 60-19
S&ME Project No. 1356-07-003
Table 5
May 2016 - Detected Analytes in Surface Water Samples
Mecklenburg County Highway 521 Landfill "Foxhole"
Permit # 60-19
S&ME Project No. 1356-07-003
EPA Appendix I Metals
Method 6010B/6020
(µg/L)
15A NCAC
2B SW-1 SW-2
EPA Appendix I Metals
Method 6010B/6020
(µg/L)
Barium 1,000 34.8 J 36.0 J
Chromium 24 2.80 J 2.73 J
Copper 2.7 2.82 J 4.51 J
Vanadium NE 4.89 7.12 J
Zinc 36 6.71 4.83 J
Notes:
(1) µg/L = micrograms per liter (parts per billion)
(3) NE = No established standard
(4) J = Reported value is between method detection limit (MDL) and method reporting limit (MRL)
(5) B = Analyte was detected in associated laboratory method blank
(6) Bold and highlighted indicates concentration potentially greater than 15A NCAC 2B
(7) Compounds not shown were not detected.
(8) Target analytes not shown were reported as below detection limits
No Volatile Organic Compounds Detected in Surface Water Samples
(2) 15A NCAC 2B = North Carolina Surface Water Quality Standards, most stringent of Freshwater, Water
Supply or Human Health
Chloroform MW-7 65 KW TRUE sewer line probable source
Antimony MW-3 89 PL FALSE
MW-8 94 PL FALSE
MW-10A 81 KW FALSE
Barium MW-2R 45 KW FALSE
MW-3 39 KW FALSE
MW-7 49 KW FALSE
MW-8 47 KW FALSE
MW-10 39 KW FALSE
MW-10A 47 KW FALSE
MW-11 47 KW FALSE
MW-11A 47 KW FALSE
MW-12 0 PA FALSE
MW-13 0 PA FALSE
Beryllium MW-2R 84 KW FALSE
MW-10A 94 PL FALSE
Chromium MW-2R 58 KW FALSE
MW-3 50 KW FALSE
MW-10A 6 PA FALSE
MW-11A 44 KW FALSE
MW-12 0 PA FALSE
MW-13 30 KW FALSE
Cobalt MW-2R 6 PA FALSE
MW-10 94 PL FALSE
Copper MW-2R 45 KW FALSE
MW-10A 47 KW FALSE
Nickel MW-2R 52 KW FALSE
MW-10 86 KW FALSE
MW-11 86 KW FALSE
MW-12 0 PA FALSE
Statistical
Analysis
Method
SSI Comments
Table 6
May 2016 - Statistical Analysis
Mecklenburg County Highway 521 Landfill "Foxhole"
Permit # 60-19
S&ME Project No. 1356-07-003
Parameter Well ID
Percent
Non-Detect
Statistical
Analysis
Method
SSI Comments
Table 6
May 2016 - Statistical Analysis
Mecklenburg County Highway 521 Landfill "Foxhole"
Permit # 60-19
S&ME Project No. 1356-07-003
Parameter Well ID
Percent
Non-Detect
Vanadium MW-3 47 KW FALSE
MW-10 47 KW FALSE
MW-10A 39 KW FALSE
MW-11A 47 KW FALSE
MW-12 0 PA FALSE
MW-13 10 PA FALSE
Zinc MW-2R 52 KW FALSE
MW-12 40 KW FALSE
Notes:
(1)SSI = Statistically Significant Increase
(2)PA = One Way Parametric Analysis of Variance (Parametric ANOVA)
Parametric ANOVA analysis is recommended by the 1992 guidance document for
parameters with fewer than 15% non-detects in a specific well.
(3)KW = Kruskal Wallis Non-Parametric Rank Analysis
Kruskal-Wallis method is recommended by the 1992 guidance document for parameters
that have 15% to 90% non-detects in a specific well.
(4)PL = Non-Parametric Inter-Well Prediction Limit Analysis
Prediction limit was used for parameters with greater than 90% non-detects in a specific well.
The 1992 guidance document recommends this method when a significant portion of the
samples are non-detect.
Appendix III – Well Sampling Logs and Laboratory Reports
Appendix IV – Statistical Analysis Procedure Sheets