6013_GreenwayNorthMeckCDLF_20170808_MetalsASD_DIN28645

August 2, 2017

Ms. Jackie Drummond Compliance Hydrogeologist Division of Waste Management - Solid Waste Section North Carolina Department of Environmental Quality
Asheville Regional Office
2090 US Highway 70 Swannanoa, NC 28778 Dear Jackie:

Subject: North Meck C&D Landfill – Permit 60-13 Greenway Waste Solutions of North Meck, LLC Demonstration Letter on Background Metals in Groundwater Samples CEC Project 111-370.001

Per 15A NCAC 13B .0544 (b) (1) (I), Civil & Environmental Consultants, Inc. (CEC), on behalf of Greenway Waste Solutions of North Meck, LLC, is submitting this Demonstration Letter to establish that a natural variation in groundwater quality has caused contamination at the aforementioned facility. Certain metals have been detected in the groundwater that is sampled and analyzed per the
approved Groundwater Monitoring Plan. These metals are regularly detected at concentrations
exceeding their respective cleanup standards as published in 15A NCAC 02L .0202 (Standards), or published Interim Maximum Contaminant Levels (IMCL). This letter presents:
• Statistical analysis used to determine metals of concern;
• Condensed historical information on the detection of metals in groundwater at the landfill;
• Information on the presence of reducing groundwater conditions and its impact on metal
solubility and mobility;
• Summary of published information on the background presence of selected metals in groundwater and stream sediments; and
• Information on mining operations in the area of the landfill and its impact of background
metals. Attachments include a site plan depicting groundwater monitoring well locations, selected field data sheets on the latest sampling event; figures on published groundwater and/or stream sediment
concentration data for selected metals, and locations of gold mining operations near the Facility.

Ms. Jackie Drummond - NCDEQ
CEC Project 111-370.0001
Page 2 August 2, 2017

Statistical Analyses and Metals of Concern
Semi-annual groundwater monitoring has been performed at the landfill for an extended period. CEC tabulated and statistically analyzed historical groundwater data for both the Closed and Infill sections of the landfill for the period 2012 thru 2017 to determine metals of concern. The criteria for selection of metals of concern are:

• Any constituent must have a minimum of two detections within 2012 and 2017 above
method detection limit (MDL);
• The geometric mean (GM) of the data for each constituent is then determined using only
values greater than MDL;
• A comparison is made between the GM against the Standard or IMCL (Standard/IMCL);
and
• If the comparison indicates the GM is greater than the Standard/IMCL, then the constituent
is a metal of concern.

Using the perimeter wells only (Point of Compliance), the analyses yielded six metals of concern:

1) Chromium (10 µg/L) – GM of 10 µg/L, 27 samples above MDL;
2) Cobalt (1 µg/L) – GM of 5.1 µg/L, 29 samples above MDL;
3) Iron (300 µg/L) – GM of 1,850 µg/L, 41 samples above the MDL;
4) Manganese (50 µg/L) – GM of 166 µg/L, 83 samples above the MDL;
5) Thallium (0.2 µg/L) – GM of 6 µg/L, 2 samples above the MDL; and
6) Vanadium (0.3 µg/L) – GM of 15.7 µg/L, 57 samples above the MDL.

Condensed Historical Information The groundwater-monitoring program at the North Meck C&D Landfill currently consists of 42 groundwater monitoring wells and the program has been ongoing since 1996. Semi-annual sampling
and analysis is conducted per the approved Groundwater Monitoring Plan. Initial metal analyses
included the RCRA 8 metals until 2011. Between 2011 and 2012, Appendix I metals were analyzed. From 2013 on, Appendix II metal analyses were added. The first available data (1999) show that barium was the first and most prevalent metal detected. Barium, cadmium, copper, mercury and selenium were observed in the historical records at levels less than their applicable current Standard.
Various semi-annual reports submitted by others state that the detected values represent background
concentrations in the Piedmont. Groundwater Conditions and Its Impact on Bedrock Metal Mobility
Two of the metals of concern, iron and manganese, are well recognized as being part of the Piedmont
bedrock/saprolite. Both of these metals are easily mobilized from the bedrock/saprolite when
Ms. Jackie Drummond - NCDEQ
CEC Project 111-370.0001
Page 3 August 2, 2017

reducing groundwater conditions are present. Field sampling logs generated by CEC personnel
during the last two low-flow groundwater-sampling events identified a majority of the groundwater
wells as having a negative Oxidation-Reduction Potential (ORP) measurement. This negative ORP indicates a reducing environment. A reducing environment allows for the converting insoluble forms of iron and manganese in the bedrock to soluble salts resulting in elevated concentrations of these metals in the groundwater. CEC has also reviewed the historical field notes from 2012 to 2016. There
are notations of high turbidity in some collected samples. Similar to the solubilizing of the iron and
manganese in reducing conditions, high-turbidity in Piedmont groundwater is well understood to increase the total metal concentrations compared to a low-turbidity sample. The revised groundwater sampling process of low-sampling now in practice should reduce the likelihood of high turbidity samples going forwards.

Published Information on Selected Metals in Background Chromium, cobalt and vanadium are also well understood to be present in the Piedmont geology. The Energy, Land and Natural Resources Division of NCDEQ published maps(1) on the measured
concentrations of these metals in stream sediments. These maps can be found in the Attachments. In
these maps, significant concentrations of these three metals are observed in sediments. For example, chromium has been identified through sampling to be detected in the range of 10 to 15 milligrams per liter in stream sediments in the general area of the Facility. Likewise, for cobalt, stream sediments have been observed to have concentrations ranging from 10 to 20 milligrams per liter in the general
area of the Facility. Vanadium is similar with greater than 180 milligrams per liter being detected in
sediments in the general area of the Facility. CEC has also included a publication and map from the United States Geological Survey (USGS) showing the presence and history of cobalt in the central North Carolina in the Attachments. Comparing these detected stream sediment concentrations to the GM concentrations of 10, 5.1 and 15.7 µg/L of chromium, cobalt and vanadium, the presence of these
metals due to naturally occurring background bedrock/saprolite is concluded.
Thallium is the last metal of concern then that needs to be evaluated with respect to its presence in the background bedrock and saprolite at the Facility. Thallium has been reported in gold deposits and non-gold bearing quartz deposits by the United States Geological Society. Gold mining has been in-
place in the Mecklenburg County area since the mid-19th century. Numerous gold mines have existed
across the County including directly west of Facility near Holbrooks Road before Old Statesville Road (see Attachments). While specific information does not exist on the mining activities in the immediate area of the Facility, the historical location of gold mines adjacent to the Facility and the overall history of gold mining in the County and surrounding areas adds credence to its presence as a
background metal. It has been detected above its method detection limit in two POC wells (MW-
8/MW-8D – Closed) once (Fall 2016) samples. It has also been detected in the background well MW-1 at the same value range (6 - 7 µg/L). The presence of the thallium in the background well; its known association with gold bearing quartz; and the presence of historical gold mining operations just west of the Facility supports the conclusion that the thallium is a naturally occurring background metal.
(1) Hoffman, J.D., and Buttleman, Kim, 1994. National Geochemical Data Base: National Uranium Resource
Evaluation Data for the Conterminous United States, U.S. Geological Survey Digital Data Series DDS-18-
A.
Ms. Jackie Drummond - NCDEQ
CEC Project 111-370.0001
Page 4 August 2, 2017

Conclusion
The presented data clearly supports the position that each of the six metals of concern detected in the Facility groundwater are due to their presence in the natural geology. These metals should then be removed from the Contaminants of Concern for the Facility at this time.

If you have any questions or comments, please feel free to contact me at [phone]. Sincerely,
CIVIL & ENVIRONMENTAL CONSULTANTS, INC.
Bruce D. Reilly, P.E. Scott L. Brown, P.E.
Senior Project Manager Vice President
Attachments Cc: Mr. John Brown – Greenway Waste Solutions

ATTACHMENTS

DATE:DWG SCALE:
DRAWN BY:CHECKED BY:APPROVED BY:
PROJECT NO:
FIGURE NO.:
CHROMIUM STREAM SEDIMENT
111-370.001AS NOTEDJULY 2017
JKS DRAFT DRAFT 1
GREENWAY WASTE SOLUTIONS
AT NORTH MECK, LLC
NORTH MECK LANDFILL
HUNTERSVILLE, NORTH CAROLINA
www.cecinc.com
1900 Center Park Drive - Suite A - Charlotte, NC 28217
Ph: 980.237.0373 · Fax: [phone]
DATE:DWG SCALE:
DRAWN BY:CHECKED BY:APPROVED BY:
PROJECT NO:
FIGURE NO.:
IRON IN STREAM SEDIMENT
111-370.001AS NOTEDJULY 2017
JKS DRAFT DRAFT 3
GREENWAY WASTE SOLUTIONS
AT NORTH MECK, LLC
NORTH MECK LANDFILL
HUNTERSVILLE, NORTH CAROLINA
www.cecinc.com
1900 Center Park Drive - Suite A - Charlotte, NC 28217
Ph: 980.237.0373 · Fax: [phone]
DATE:DWG SCALE:
DRAWN BY:CHECKED BY:APPROVED BY:
PROJECT NO:
FIGURE NO.:
MANGANESE IN STREAM SEDIMENT
111-370.001AS NOTEDJULY 2017
JKS DRAFT DRAFT 4
GREENWAY WASTE SOLUTIONS
AT NORTH MECK, LLC
NORTH MECK LANDFILL
HUNTERSVILLE, NORTH CAROLINA
www.cecinc.com
1900 Center Park Drive - Suite A - Charlotte, NC 28217
Ph: 980.237.0373 · Fax: [phone]
DATE:DWG SCALE:
DRAWN BY:CHECKED BY:APPROVED BY:
PROJECT NO:
FIGURE NO.:
VANADIUM IN STREAM SEDIMENT
111-370.001AS NOTEDJULY 2017
JKS DRAFT DRAFT 5
GREENWAY WASTE SOLUTIONS
AT NORTH MECK, LLC
NORTH MECK LANDFILL
HUNTERSVILLE, NORTH CAROLINA
www.cecinc.com
1900 Center Park Drive - Suite A - Charlotte, NC 28217
Ph: 980.237.0373 · Fax: [phone]
UNITED STATES DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
Distribution of cobalt in heavy-mineral-concentrate samples
from the Charlotte 1° x 2° quadrangle,
North Carolina and South Carolina
by
W. R. Griffitts, J. W. Whitlow, D. F. Siems,
K. A. Duttweiler, and J. D. Hoffman
Open-File Report 84-843-L
This report is preliminary and has not been reviewed for conformity with U.S.
Geological Survey editorial standards and stratigraphic nomenclature. Use of
brand or manufacturer's names is for descriptive purposes only and does not
constitute endorsement by the U.S. Geological Survey.
1984
This map is a product of a geochemical survey of the Charlotte 1° x 2°
quadrangle, North Carolina and South Carolina, begun in 1978 that is part of a
multidisciplinary study to determine the mineral potential of the area.
Correlative studies are the completion of a geologic map of the quadrangle and
aeromagnetic, aeroradiation, and gravity surveys (Uilson and Daniels, 1981).
The Charlotte quadrangle provides a nearly complete section across the
Piedmont: its northwestern corner is in the Blue Ridge, its southeastern
corner is over a basin of Triassic sedimentary rocks only a few miles from the
Coastal Plain. All of the quadrangle except the southeastern corner is
underlain by crystalline rocks of Precambrian and Paleozoic age metamorphosed
to greenschist facies in the Carolina Slate Belt and to amphibolite facies
farther west. Both premetamorphic and post metamorphic intrusive rocks are
present. The rocks have been weathered to permeable saprolite reaching depths
of 200 feet (60 meters) in the Inner Piedmont. Because of the thorough
leaching, most soils are acidic.
In making the geochemical survey, we took samples of sediment within a
few miles of the heads of major streams and of the tributaries of these
streams, keeping the size of the drainage basin small. By doing so, we
usually reduce the variety of rocks that contribute detritus to the sample,
thus facilitating a correlation between sample composition and the geology of
the drainage basin. At the same time, we reduce the chance that a localized
cloudburst has buried the sample site with sediment from a small part of the
drainage basin, thus reducing the validity of the sample as an approximate
composite of the rocks of the whole basin. Nevertheless, the samples are not
all geologically and geochemically equivalent. For instance, at some sites in
the mountainous area in the northwestern part of the quadrangle, many clasts
in the stream sediment are several yards (meters) across and collection of
fine detritus suitable for a sample required a 1/2-hour search. Not far to
the east, the finer sediment was abundant.
In the Piedmont, the usual procedure was to sample rather coarse
sediment pebble- or cobble-containing gravel and to dig deeply to the bottom
of the alluvial bed or to a compact clay layer. The coarsest particles in the
gravel boulders, cobbles, and coarse pebbles were excluded from the sample,
which then consisted of about 10 Ibs (4 1/2 kg) of clay to granule or fine
gravel sized material. The heavy minerals were extracted from this unsifted
material at the sample site with a gold pan. Samples taken in the same manner
on earlier projects were also used to get better coverage of the Inner
Piedmont than we would have had otherwise.
The quartz, feldspar, and other minerals of specific gravity below 2.89
were removed from the pan concentrate by floating them with bromoform. The
heavy-mineral concentrate cleaned in that way was then separated magnetically
into four fractions. The first was removed with a hand magnet, or an
equivalent instrument, and not studied. The remaining concentrate was passed
through a Frantz Isodynamic Separator at successive current settings of 0.5
ampere and 1 ampere with 15° side slope and 25° forward slope. The material
removed from the sample at 0.5 ampere and 1 ampere will be referred to as the
M-5 and Ml concentrates or fractions, respectively, and the nonmagnetic
material at 1 ampere will be referred to as the NM concentrate or fraction.
Most common ore minerals occur mainly in the NM fraction, making them and
their contained metals easier to find and to identify. The NM fraction also
1
contains zircon, sillimanite, kyanite, spinel, apatite, sphene, and the TiC^
minerals. It is generally the most useful fraction. The Ml fraction is
largely monazite in the Inner Piedmont. Because of interferences caused by
cerium during spectrographic analysis and the high content of radiogenic lead
in the monazite, it was necessary to remove it from the bulk concentrates to
improve the quality of analyses and to permit recognition of lead, possibly
derived from mineral deposits, in the NM and M-5 fraction. East of the Inner
Piedmont the Ml concentrate contained very abundant epidote, clinozoisite,
mixed mineral grains, including ilmenite partly converted to leucoxene,
staurolite, and locally abundant spinel. The M-5 concentrate contains
abundant garnet in the Inner Piedmont, dark ferromagnesian minerals in the
Charlotte Belt, and ilmenite in most provinces.
Mineral proportions in each magnetic fraction were estimated using a
binocular microscope. Minerals of special interest were identified optically
or by X-ray diffraction. The time available did not permit a thorough
mineralogic study of all concentrates. Metal-rich minerals were sought in all
samples that were shown by the spectrograph to contain metal in unusually high
concentrations. After establishing the presence of a metal-rich mineral, the
variations in metal contents among the concentrates were inferred to indicate
variations in the content of metalliferous minerals.
Each fraction was analyzed semiquantitatively for 31 elements using a
six-step, D.C. arc, optical-emission spectrographic method (Grimes and
Marranzino, 1968). The semiquantitative spectrographic values are reported as
one of six steps per order of magnitude (1, 0.7, 0.5, 0.3, 0.2, 0.15, and
multiples of 10 of these numbers) and the values are the approximate geometric
midpoints of the concentration ranges. The precision of the method has been
shown to be within one adjoining reporting interval on each side of the
reported values 83 percent of the time and within two adjoining intervals on
each side of the reported value 96 percent of the time (Motooka and Grimes,
1976).
The lower limits of spectrographic determination for the 5 elements that
are mentioned in this report are, in parts per million: cobalt, 10; gold, 20;
niobium, 50; and tin, 20.
All analytical data for sample material other than concentrates are taken
from a report by Ferguson (1979). Such sample material is referred to as
"silt" in this report.
Most samples were taken by J. W. Whitlow and W. R. Griffitts. Lesser
numbers were taken by D. F. Siems, A. L. Meier, and K. A. Duttweiler. The
mineral analyses were made by W. R. Griffitts, K. A. Duttweiler, J. W.
Whitlow, and C. L. Bigelow, with special mineral determinations by Theodore
Botinelly. All spectrographic analyses were made by D. F. Siems, in part from
plates prepared by K. A. Duttweiler. Steve McDanal and Christine McDougal
were responsible for entering and editing the locality and spectrographic data
in the RASS computer file. Many maps were subsequently plotted from this file
by H. V. Alminas, L. 0. Wilch, and J. D. Hoffman. Most mineral distribution
maps were plotted by K. A. Duttweiler.
Cobalt is widespread in rather high concentrations in the M-5
concentrates and common but less widespread in the NM concentrates. It is
2
particularly widespread in the Carolina Slate Belt. In much of the
quadrangle, cobalt is so commonly associated with gold as to indicate that
both were involved in common episodes of mineralization. Cobalt is not
closely associated with mafic rocks, as is indicated by the high cobalt
contents of magnesium-poor M-5 concentrates (plate 1). The M-5 magnetic
fraction contains the dark silicate minerals in our concentrates; most of
those minerals have magnesium as a major component, so their scarcity
indicates that mafic rocks, rich in ferromagnesian minerals cannot be
prominent in the drainage basins.
No cobalt minerals were recognized in our investigation. The abundance
of manganese in the M-5 concentrates collected near Salisbury suggests that
the cobalt may now be in black manganese oxide minerals, some of which are
known to be cobalt accumulators.
A row of clusters of cobalt-rich sample sites passes west-northwest from
near the southeastern corner of the quadrangle to the vicinity of Charlotte.
The mineralized area near Charlotte has long been known and exploited for
gold. The area near the southeastern corner of the quadrangle, in eastern
Union County, has not been exploited for any minerals.
A cluster of cobalt-rich sample sites near Blacksburg also yields gold
and high-zinc values. That general area contains gold-quartz veins and
several kinds of iron deposits: gossans; layered quartz-hematite iron
formation; and black oxides in skarn. The cobalt concentrations may be
related to one or more of these types of deposit.
A series of 4 cobalt-rich samples were collected along a line that trends
north-northeast about 5 miles southeast of Lexington. The trend is similar to
the trends of faults at the northern end of the Gold Hill fault in the
vicinity, so the cobalt may have been deposited in minor, unmapped, faults
related to the major ones. The Gold Hill fault itself does not yield cobalt-
rich samples.
An unusually large group of sites is found over and around a granite
pluton south of Salisbury and extends as far west as Kannopolis. The cobalt
here is associated with gold, as in most places in the quadrangle, but it also
is accompanied by niobium and tin. The granite pluton is the source for the
niobium and tin, but the sources of the cobalt and gold is unknown.
The cobalt content of nonmagnetic concentrates calls attention to some of
the same areas as that of M-5 concentrates. The area south of Salisbury is
not prominent in the values in nonmagnetic concentrates; the area near
Blacksburg remains prominent.
The cobalt content of minus-100-mesh sediment is rather high in parts of
the eastern Charlotte Belt and eastern and northern Carolina Slate Belt.
Unlike the cobalt in M-5 concentrates, the high values in silt are not
generally in gold areas, but are between gold areas.
References
Ferguson, R. B., 1979, Athens, Charlotte, Greenville, and Spartanburg NTMS
1° x 2° quadrangle areas: Supplemental data release: U.S. Department of
Energy, Grand Junction, Colorado, Open-File Report GJBX 73(79), 124 p.
Grimes, D. J., and Marranzino, A. P., 1968, Direct-current arc and alternating
current spark emission spectrographic field methods for the
semiquantitative analysis of geologic materials: U.S. Geological Survey
Circular 591, 6 p.
Heffner, J. D., and Ferguson, R. B., 1978, Charlotte NTMS area, North Carolina
and South Carolina: Preliminary Data Release: U.S. Department of
Energy, Grand Junction, Colorado, Open-File Report GJBX 40(78).
Motooka, J. M., and Grimes, D. M., 1976, Analytical precision of one-sixth
order semiquantitative spectrographic analysis: U.S. Geological Survey
Circular 738, 25 p.
Wilson, F. A., and Daniels, D. L., 1980, Simple Bouguer gravity map of the
Charlotte 1° x 2° quadrangle, North Carolina and South Carolina: U.S.
Geological Survey Miscellaneous Investigations Series Map I-1251-A.
REFERENCE
NORTH
DATE:DWG SCALE:
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PROJECT NO:
FIGURE NO.:
SITE AREA TOPO SHOWING GOLD DEPOSITES
111-370.001AS NOTEDAUGUST 2017
JKS DRAFT DRAFT 6
GREENWAY WASTE SOLUTIONS
AT NORTH MECK, LLC
NORTH MECK LANDFILL
HUNTERSVILLE, NORTH CAROLINA
www.cecinc.com
1900 Center Park Drive - Suite A - Charlotte, NC 28217
Ph: 980.237.0373 · Fax: [phone]
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DESCRIPTIONDATENOREVISION RECORDwww.cecinc.com1900 Center Park Drive - Suite A - Charlotte, NC 28217Ph: 980.237.0373 · Fax: [phone]DATE:DWG SCALE:DRAWN BY:CHECKED BY:APPROVED BY:PROJECT NO:SHEET OF
DRAWING NO.:SITE MAP 111-370.00011" = 200'JANUARY 2017JKSEHSEHS
1GREENWAY WASTE SOLUTIONS OFNORTH MECK, LLCNORTH MECKLENBURG LANDFILLHUNTERSVILLE, NCNORTH