3402_Forsyth_HanesMillRoad_MSWLF_Closed_Unlined_MNA_FID1772519_20230207

hdrinc.com
February 3, 2023
Ms. Jaclynne Drummond, Compliance Hydrogeologist
NC Department of Environmental Quality
Division of Waste Management, Solid Waste Section
1646 Mail Service Center
Raleigh, NC 27699-1646
Re: Monitored Natural Attenuation Effectiveness Report
Hanes Mill Road Sanitary Landfill
Permit No. 34-02
Winston-Salem, North Carolina
Dear Ms. Drummond:
On behalf of City of Winston-Salem, HDR Engineering, Inc. of the Carolinas (HDR) is
submitting this Monitored Natural Attenuation Effectiveness Report for the Spring 2022 event,
as requested in correspondence from the North Carolina Department of Environment and
Natural Resources (NCDENR), dated September 22, 2008.
The modeling results indicate that the input parameters for the BIOCHLOR natural attenuation
screening model are applicable and that biodegradation of chlorinated organic compounds via
monitored natural attenuation (MNA) remains active at the site.
In 2022, the BIOCHLOR scores have generally decreased from the 2021 scores, indicating
slightly limited to adequate evidence of biodegradation. BIOCHLOR output for monitoring wells
OW-3, OW-4, OW-1 OD and OW-17D for the March 2022 sampling event are included as
Attachment 1.
Based on these data, HDR reviewed the First Semi -Annual 2022 Water Quality Monitoring
Report prepared by Golder Associates NC, Inc. to substantiate the BIOCHLOR results.
Specifically, HDR reviewed groundwater quality data from the March 2022 sampling event for
empirical evidence of biodegradation through detection of tetrachloroethene (PCE) daughter
products. If biodegradation is occurring, concentrations of PCE should decrease over time,
while concentrations of trichloroethene (TCE), 1,2-dichloroethene (DCE), and vinyl chloride
(VC) should increase as PCE breaks down to its daughter products. HDR prepared
concentration versus time graphs for wells OW-3, OW-4, OW-1 OD, and OW-17D to evaluate
trends in chlorinated volatile organic compounds from 2009 to through Spring 2022
(Attachment 2).
440 S Church Street, Suite 1200, Charlotte, NC 28202-2075
704.338.6700

City of Winston-Salem I Hanes Mill Road Sanitary Landfill ���
Monitored Natural Attenuation Effectiveness Report
The concentration of PCE and TCE have trended downward in wells closer to the waste mass (OW-3 and
OW-4), while the concentrations of TCE, 1,2-dichloroethene, and vinyl chloride appear to have increased
slightly since 2009 in wells OW-10D and OW-17D, located further downgradient of the waste mass
source. The slight increase of TCE, 1,2-dichloroethene, and vinyl chloride indicate that generation of PCE
daughter products is occurring.
The trends observed in laboratory data do not directly support the BIOCHLOR results for the Spring 2022
modeling period. One potential explanation for variability in concentrations could be minor changes in flow
direction between seasons or between years. A second potential explanation for the conflicting
interpretations is that BIOCHLOR was designed as a linear two-dimensional attenuation model assuming
a single point source of groundwater impacts. The Hanes Mill Road Landfill does not represent a single
point source for impacts, as the site -specific contaminants of concern could be distributed throughout
some or all of the 71-acre closed unlined facility. Additionally, given the areal extent of the landfill,
components of groundwater likely flow southeast toward South Branch Creek in the vicinity of wells OW-3
and OW-4 and southwest toward Grassy Creek in the vicinity of wells OW-10D and OW-17D. Thus, a
modeled flow path from OW-3 to OW-4 to OW-10D to OW-17D is non -linear and unlikely to be
represented adequately by the BIOCHLOR model.
While HDR understands that modeling via BIOCHLOR is required by the NCDEQ, we recommend that
trending of chlorinated VOCs and daughter products be used to support evidence that biodegradation is
continuing at the closed unlined facility.
Please contact us with any questions or concerns regarding this report.
Sincerely,
HDR Engineering, Inc. of the Carolinas
Mark P. Filardi, PG Michael D. Plummer
Associate, Senior Geologist SAA Waste Section Manager
cc: Jan McHargue, PE, City of Winston-Salem
file
Enclosures

City of Winston-Salem I Hanes Mill Road Sanitary Landfill ���
Monitored Natural Attenuation Effectiveness Report

City of Winston-Salem I Hanes Mill Road Sanitary Landfill ���
Monitored Natural Attenuation Effectiveness Report
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Attachment 1
BIOCHLOR Modeling Results for March 2022 Monitoring Period Hanes
Landfill Closed Unlined Cell
Assumption
The maximum chlorinated compound concentrations (PCE, TCE, DCE, and VC) from the
groundwater monitoring available from 2001 and 2006 (ETH) were used because the actual
source concentrations are unknown.
Model Input Data
1. Advection: Seepage Velocity, hydraulic gradient, and effective porosity (presented in
figure below) are all based on site conditions at the landfill.
2. Dispersion Input Parameter: ax, ay/ax, and az/ax inputs are all based on the
instruction for the BIOCHLOR program
3. Adsorption: Default values from the BIOCHLOR program were applied. A soil bulk
density of 1.6 kg/L, foc of 1.8 x 10-1, and Koc values of 426 L/kg (PCE), 130 L/kg (TCE),
125 L/kg (DCE), 30 L/kg (VC), and 302 L/kg (ETH) were used within the model to
calculate a retardation factor of 2.87. This value was used throughout the rest of the
model.
4. Biotransformation: The biotransformation first orders Decay coefficients lamda (1/yr)
for PCE-TCE (0.45), TCE-DCE (0.55), DCE-VC (0.8), and VC-ETH (12) from Zone 1
were obtained based on Table 2.2 of the BIOCHLOR Addendum Manual (March 2002);
and were adjusted by fitting 2022 field VOC data to the sequential 1st order decay
modeling VOC concentration curve.
5. General: Only the VOC data from 2001 to current period for the OW wells were
available and the source VOC concentrations unknown. The maximum groundwater
VOC concentrations from 2001 and 2006 were used as the source input and the
modeling time is therefore set for 21 years (from 2001 to 2022). The model width is 1000
ft (limited zone of VOC detection based on historic data) and modeling length is 600 ft
(maximum distance from landfill to the down gradient stream).
6. Source Data: The source data entered into the model determine how the concentrations
in the source area change over time. The source thickness in the saturated zone is 50 ft.
For the source concentrations the maximum groundwater VOC concentrations from

2001 and 2006 (ETH) were used. These are: PCE = 0.044 mg/L; TCE 0.21 mg/L; DCE _
0.97 mg/L; VC = 0.66 mg/L; and ETH = 0.013 mg/L. The maximum Decay Rate Constants
ks (1/yr) allowed by the model were used.
7. Field Data: The groundwater data collected in the field efforts from 2022 were used for
the PCE, TCE, DCE and VC concentrations for OW-3 (20 ft from the landfill boundary),
OW-4 (30 ft from the landfill boundary), OW-10D (215 ft from the landfill boundary), and
OW-17D (450 ft from the landfill boundary). The field data values can be found in the
BIOCHLOR Natural Attenuation Decision Support System figure below in the seventh
section (Field Data for Comparison).
Results
1. MNA Screening Score: The MNA screening scores were 15, 11, 12, and 9 for OW-3,
OW-4, OW-1 OD, and OW-17D, respectively for the March 2022 event. A score from 6 to
14 means there is limited evidence for anaerobic biodegradation of chlorinated organics,
which was seen in wells OW-17D, OW-4, and OW-10D. Well OW-3 was in the range of
15 to 20 which means adequate evidence for anaerobic biodegradation of chlorinated
organics.
2. Biochlor Modeling Results: The Biochlor modeling results of PCE, TCE, DCE and VC
for both No -Degradation and Biotransformation for 0 to 600 ft from the source (landfill
waste border) are tabulated for each compound (see figures below). These results are
compared to the field data collected in March 2022 from OW-3, OW-4, OW-10D and
OW-17D. The results showed that the concentration of PCE and VC slightly decreased
with distance from the landfill. The concentration of TCE appeared to be constant with
distance from the landfill, while DCE was not detected in either well. The model
estimated PCE, TCE and DCE concentrations appear to increase with distance to the
landfill. The dissolved chlorinated solvent concentrations along plume centerline (mg/L)
at Z=0 figures below show the modeled No Degradation (red line), Biotransformation
(blue line) and field data from site (black box with yellow plus sign). The model estimated
concentrations with biotransformation for all constituents match more closely the value
and magnitude of the value in the biotransformation line, however only VC field data
from the site show the same general trend as the Biotransformation line. The model
estimated TCE concentration at 420 ft (6 pg/L) and 480 ft (5 pg/L) downgradient from
the landfill were still slightly above the 2L standard (3 pg/L). The modeled TCE
concentration decreased to the 2L Standard at 540 ft downgradient from the landfill.
These model -estimated results indicate that the MNA (biodegradation) of the chlorinated
organic compounds have limited evidence for anaerobic biodegradation of chlorinated
organics.

March 2022
Natural Attenuation
Screening
Protocol
Interpretation
Score
O V V`A' —3
Score: 15
Scroll to End of Table
Inadequate evidence for anaerobic biodegradation* of chlorinated organics
0 to 5
Limited evidence for anaerobic biodegradation* of chlorinated organics
6 to 14
The following is taken from the usEPA protocol [usEPA, Igga>.
The results of this scoring process have no regulatory
significance.
Adequate evidence for anaerobic biodegradation* of chlorinated organics
15 to 20
11 Strong evidence for anaerobic biodegradation* of chlorinated organics
>20
Concentration in " reductive dechlonnation Points
Analysis Most Contam. Zone Interpretation Yes No Awarded
Oxygen*
<0.5 mg/L
Tolerated, suppresses the reductive pathway at higher
concentrations
0
3
> 5mg/L
Not tolerated; however, VC may be oxidized aerobically
O
0
Nitrate*
<1 mg/L
At higher concentrations may compete with reductive
pathway
2
Iron II*
>1 mg/L
Reductive pathway possible; VC may be oxidized under
Fe(Ill)-reducing conditions
��
3
Sulfate*
<20 mg/L
At higher concentrations may compete with reductive
pathway
L;
2
Sulfide*
>1 mg/L
Reductive pathway possible
0
Methane*
>0.5 mg/L
Ultimate reductive daughter product, VC Accumulates
0
0
0
Oxidation
Reduction
Potential* (ORP)
<50 millivolts (mV)
Reductive pathway possible
O
0
1
<-100mV
Reductive pathway likely
0
(0)
0
pH*
5 < pH < 9
Optimal range for reductive pathway
0
TOC
>20 mg/L
Carbon and energy source; drives dechlorination; can be
natural or anthro o enic
0
0
Temperature*
>20°C
At T >20°C biochemical process is accelerated
0
%
0
Carbon Dioxide
>2x background
Ultimate oxidative daughter product
O
0
Alkalinity
>2x background
Results from interaction of carbon dioxide with aquifer
minerals
0
(0)
0
Chloride*
>2x background
Daughter product of organic chlorine
0
0
2
Hydrogen
>1 nM
Reductive pathway possible, VC may accumulate
0
(0)
0
Volatile Fatty Acids
>0.1 mg/L
Intermediates resulting from biodegradation of aromatic
compounds; carbon and energy source
0
0
BTEX*
>0.1 mg/L
Carbon and energy source; drives dechlorination
0
0
PCE*
Material released
(0)
0
TCE*
Daughter product of PCE of
0
0
DCE*
Daughter product of TCE.
If cis is greater than 80% of total DCE it is likely a daughter
product of TCE'/; 1,1-DCE can be a Chem. reaction product of TCA
(0)
2
VC*
Daughter product of DCE'/
0
0
1,1,1-
Trichloroethane*
Material released
0
0
0
DCA
Daughter product of TCA under reducing conditions
0
0
Carbon
Tetrachloride
Material released
0
0
Chloroethane*
Daughter product of DCA or VC under reducing conditions
O
0
Ethene/Ethane
>0.01 mg/L
Daughter product of VC/ethene
0
0
>0.1 mg/L
Daughter product of VC/ethene
0
0
Chloroform
Daughter product of Carbon Tetrachloride
0
0
Dichloromethane
Daughter product of Chloroform
0
0
* required analysis.
a/ Points awarded only if it can be shown that the compound is a daughter product SCORE [ZCset
(i.e., not a constituent of the source NAPL).

March 2022
Natural Attenuation
Screening
Protocol
Interpretation
Score
OW-4
Score: 11
Scroll to End of Table
Inadequate evidence for anaerobic biodegradation* of chlorinated organics
0 to 5
Limited evidence for anaerobic biodegradation* of chlorinated organics
6 to 14
The following is taken from the usEPA protocol [usEPA, Igga>.
The results of this scoring process have no regulatory
significance.
Adequate evidence for anaerobic biodegradation* of chlorinated organics
15 to 20
11 Strong evidence for anaerobic biodegradation* of chlorinated organics
>20
Concentration in " reductive dechlonnation Points
Analysis Most Contam. Zone Interpretation Yes No Awarded
Oxygen*
<0.5 mg/L
Tolerated, suppresses the reductive pathway at higher
concentrations
C
3
> 5mg/L
Not tolerated; however, VC may be oxidized aerobically
0
0
Nitrate*
<1 mg/L
At higher concentrations may compete with reductive
pathway
(0)2
Iron II*
>1 mg/L
Reductive pathway possible; VC may be oxidized under
Fe(Ill)-reducing conditions
0
���
0
Sulfate*
<20 mg/L
At higher concentrations may compete with reductive
pathway
L;
2
Sulfide*
>1 mg/L
Reductive pathway possible
0
0
Methane*
>0.5 mg/L
Ultimate reductive daughter product, VC Accumulates
0
0
0
Oxidation
Reduction
Potential* (ORP)
<50 millivolts (mV)
Reductive pathway possible
0
O
0
<-100mV
Reductive pathway likely
0
(0)
0
pH*
5 < pH < 9
Optimal range for reductive pathway
0
TOC
>20 mg/L
Carbon and energy source; drives dechlorination; can be
natural or anthro o enic
0
0
Temperature*
>20°C
At T >20°C biochemical process is accelerated
0
%
0
Carbon Dioxide
>2x background
Ultimate oxidative daughter product
0
0
Alkalinity
>2x background
Results from interaction of carbon dioxide with aquifer
minerals
0
(0)
0
Chloride*
>2x background
Daughter product of organic chlorine
0
0
Hydrogen
>1 nM
Reductive pathway possible, VC may accumulate
0
0
Volatile Fatty Acids
>0.1 mg/L
Intermediates resulting from biodegradation of aromatic
compounds; carbon and energy source
0
0
BTEX*
>0.1 mg/L
Carbon and energy source; drives dechlorination
0
0
PCE*
Material released
(0)
0
TCE*
Daughter product of PCE ai
v
2
DCE*
Daughter product of TCE.
If cis is greater than 80% of total DCE it is likely a daughter
product of TCE'/; 1,1-DCE can be a Chem. reaction product of TCA
0
0
VC*
Daughter product of DCE'/
2
1,1,1-
Trichloroethane*
Material released
0
0
0
DCA
Daughter product of TCA under reducing conditions
0
0
Carbon
Tetrachloride
Material released
0
0
Chloroethane*
Daughter product of DCA or VC under reducing conditions
0
0
Ethene/Ethane
>0.01 mg/L
Daughter product of VC/ethene
0
0
>0.1 mg/L
Daughter product of VC/ethene
0
0
Chloroform
Daughter product of Carbon Tetrachloride
0
0
Dichloromethane
Daughter product of Chloroform
0
0
* required analysis.
a/ Points awarded only if it can be shown that the compound is a daughter product SCORE [ZCset
(i.e., not a constituent of the source NAPL).

March 2022
Natural Attenuation
Screening
Protocol
Interpretation
Score
OW-1 OD
Score: 10
Scroll to End of Table
Inadequate evidence for anaerobic biodegradation* of chlorinated organics
0to5
Limited evidence for anaerobic biodegradation* of chlorinated organics
6 to 14
The following is taken from the usEPA protocol [usEPA, Igga>.
The results of this scoring process have no regulatory
significance.
Adequate evidence for anaerobic biodegradation* of chlorinated organics
15 to 20
11 Strong evidence for anaerobic biodegradation* of chlorinated organics
>20
Concentration in " reductive dechlonnation Points
Analysis Most Contam. Zone Interpretation Yes No Awarded
Oxygen*
<0.5 mg/L
Tolerated, suppresses the reductive pathway at higher
concentrations
C
3
> 5mg/L
Not tolerated; however, VC may be oxidized aerobically
0
0
Nitrate*
<1 mg/L
At higher concentrations may compete with reductive
pathway
(0)2
Iron II*
>1 mg/L
Reductive pathway possible; VC may be oxidized under
Fe(Ill)-reducing conditions
0
���
0
Sulfate*
<20 mg/L
At higher concentrations may compete with reductive
pathway
L;
2
Sulfide*
>1 mg/L
Reductive pathway possible
0
0
Methane*
>0.5 mg/L
Ultimate reductive daughter product, VC Accumulates
0
0
0
Oxidation
Reduction
Potential* (ORP)
<50 millivolts (mV)
Reductive pathway possible
O
0
1
<-100mV
Reductive pathway likely
0
(0)
0
pH*
5 < pH < 9
Optimal range for reductive pathway
0
TOC
>20 mg/L
Carbon and energy source; drives dechlorination; can be
natural or anthro o enic
0
0
Temperature*
>20°C
At T >20°C biochemical process is accelerated
0
%
0
Carbon Dioxide
>2x background
Ultimate oxidative daughter product
0
0
Alkalinity
>2x background
Results from interaction of carbon dioxide with aquifer
minerals
0
(0)
0
Chloride*
>2x background
Daughter product of organic chlorine
0
0
Hydrogen
>1 nM
Reductive pathway possible, VC may accumulate
0
0
Volatile Fatty Acids
>0.1 mg/L
Intermediates resulting from biodegradation of aromatic
compounds; carbon and energy source
0
0
BTEX*
>0.1 mg/L
Carbon and energy source; drives dechlorination
0
0
PCE*
Material released
(0)
0
TCE*
Daughter product of PCE ai
v
2
DCE*
Daughter product of TCE.
If cis is greater than 80% of total DCE it is likely a daughter
product of TCE'/; 1,1-DCE can be a Chem. reaction product of TCA
0
0
VC*
Daughter product of DCE'/
0
0
1,1,1-
Trichloroethane*
Material released
0
0
0
DCA
Daughter product of TCA under reducing conditions
0
0
Carbon
Tetrachloride
Material released
0
0
Chloroethane*
Daughter product of DCA or VC under reducing conditions
0
0
Ethene/Ethane
>0.01 mg/L
Daughter product of VC/ethene
0
0
>0.1 mg/L
Daughter product of VC/ethene
0
0
Chloroform
Daughter product of Carbon Tetrachloride
0
0
Dichloromethane
Daughter product of Chloroform
0
0
* required analysis.
a/ Points awarded only if it can be shown that the compound is a daughter product SCORE [ZCset
(i.e., not a constituent of the source NAPL).

March 2022
Natural Attenuation
Screening
Protocol
Interpretation
Score
OW-17D
Score: 9
Scroll to End of Table
Inadequate evidence for anaerobic biodegradation* of chlorinated organics
0to5
Limited evidence for anaerobic biodegradation* of chlorinated organics
6 to 14
The following is taken from the usEPA protocol [usEPA, Igga>.
The results of this scoring process have no regulatory
significance.
Adequate evidence for anaerobic biodegradation* of chlorinated organics
15 to 20
11 Strong evidence for anaerobic biodegradation* of chlorinated organics
>20
Concentration in " reductive dechlonnation Points
Analysis Most Contam. Zone Interpretation Yes No Awarded
Oxygen*
<0.5 mg/L
Tolerated, suppresses the reductive pathway at higher
concentrations
C
3
> 5mg/L
Not tolerated; however, VC may be oxidized aerobically
0
0
Nitrate*
<1 mg/L
At higher concentrations may compete with reductive
pathway
(0)2
Iron II*
>1 mg/L
Reductive pathway possible; VC may be oxidized under
Fe(Ill)-reducing conditions
0
���
0
Sulfate*
<20 mg/L
At higher concentrations may compete with reductive
pathway
L;
2
Sulfide*
>1 mg/L
Reductive pathway possible
0
0
Methane*
>0.5 mg/L
Ultimate reductive daughter product, VC Accumulates
0
0
0
Oxidation
Reduction
Potential* (ORP)
<50 millivolts (mV)
Reductive pathway possible
0
O
0
<-100mV
Reductive pathway likely
0
(0)
0
pH*
5 < pH < 9
Optimal range for reductive pathway
0
TOC
>20 mg/L
Carbon and energy source; drives dechlorination; can be
natural or anthro o enic
0
0
Temperature*
>20°C
At T >20°C biochemical process is accelerated
0
%
0
Carbon Dioxide
>2x background
Ultimate oxidative daughter product
0
0
Alkalinity
>2x background
Results from interaction of carbon dioxide with aquifer
minerals
0
(0)
0
Chloride*
>2x background
Daughter product of organic chlorine
0
0
Hydrogen
>1 nM
Reductive pathway possible, VC may accumulate
0
0
Volatile Fatty Acids
>0.1 mg/L
Intermediates resulting from biodegradation of aromatic
compounds; carbon and energy source
0
0
BTEX*
>0.1 mg/L
Carbon and energy source; drives dechlorination
0
0
PCE*
Material released
(0)
0
TCE*
Daughter product of PCE ai
v
2
DCE*
Daughter product of TCE.
If cis is greater than 80% of total DCE it is likely a daughter
product of TCE'/; 1,1-DCE can be a Chem. reaction product of TCA
0
0
VC*
Daughter product of DCE'/
0
0
1,1,1-
Trichloroethane*
Material released
0
0
0
DCA
Daughter product of TCA under reducing conditions
0
0
Carbon
Tetrachloride
Material released
0
0
Chloroethane*
Daughter product of DCA or VC under reducing conditions
0
0
Ethene/Ethane
>0.01 mg/L
Daughter product of VC/ethene
0
0
>0.1 mg/L
Daughter product of VC/ethene
0
0
Chloroform
Daughter product of Carbon Tetrachloride
0
0
Dichloromethane
Daughter product of Chloroform
0
0
* required analysis.
a/ Points awarded only if it can be shown that the compound is a daughter product SCORE [ZCset
(i.e., not a constituent of the source NAPL).

DISSOLVED CHLORINATED SOLVENT CONCENTRATIONS ALONG PLUME CENTERLINE (mg/L) at Z=0
Distance from Source (ft)
PCE
No Degradation
Biotransformation
0
60
120
180
240
300
360
420
480
540
600
0.044
0.043
0.042
0.039
0.035
0.030
0.025
0.020
0.015
0.010
0.007
0.0440
0.031
0.021
0.014
0.010
0.006
0.004
0.003
0.002
0.001
0.001
20 30
Field Data from Site 1 0.004
—No Degradation/Production
0.05
J 0.05
im 0.04
E 0.04
c 0.03
0.03
0.02
c 0.02
v 0.01
0 0.01
U 0.00
0 100
Monitoring Well Locations (ft)
215 450
0.004 0.003
—Sequential 1st Order Decay a Field Data from Site
200 300 400 500 600 700
Distance From Source (ft.)
See PCE
See TCE
See DCE
See VC
See ETH
Time:
20.0 Years Return to
Replay To All To Array
Log <�:�Linear Input

DISSOLVED CHLORINATED SOLVENT CONCENTRATIONS ALONG PLUME CENTERLINE (mg/L) at Z=0
Distance from Source (ft)
TCE
No Degradation
Biotransformation
0
60
120
180
240
300
360
420
480
540
600
0.210
0.207
0.200
0.186
0.167
0.144
0.119
0.094
0.070
0.049
0.033
0.2100
0.144
0.098
0.066
0.044
0.029
0.018
0.012
0.007
0.004
0.003
Field Data from Site
20 30
1 0.007
Monitoring Well Locations (ft)
215 450
0.007 0.007
—No Degradation/Production
—Sequential 1st Order Decay a Field Data from Site
0.25
T
See PCE
J
m 0.20
See TCE
c 0.15
G
0
See DCE
0.10
0
See VC
0.05
600
0
U
o
o
See ETH
0.00
0 100
200 300 400 500 600 700
Distance From Source (ft.)
Time:
20.0 Years Return
Replay
to
To All
To Array
Log '�:�Linear Input

DISSOLVED CHLORINATED SOLVENT CONCENTRATIONS ALONG PLUME CENTERLINE (mg/L) at Z=0
Distance from Source (ft)
vc
No Degradation
Biotransformation
20 30
Field Data from Site 0.050 0.001
—No Degradation/Production
0.07
J 0.06
E 0.05
G 0.04
0 0.03
0.02
0.01
O
U 0.00
0 100
Monitoring Well Locations
215 450
0.001
—Sequential 1st Order Decay
200 300
0 Field Data from Site
600
400 500 600
Distance From Source (ft.)
700
See PCE
See TCE
See VC
See ETH
Time:
20.0 Years Return to
Replay To All To Array
Log <�:�Linear Input

DISSOLVED CHLORINATED SOLVENT CONCENTRATIONS ALONG PLUME CENTERLINE (mg/L) at Z=0
Distance from Source (ft)
DCE
No Degradation
Biotransformation
0
60
120
180
240
300
360
420
480
540
600
0.970
0.957
0.923
0.860
0.771
0.665
0.549
0.433
0.323
0.228
0.152
0.9700
0.584
0.351
0.210
0.125
0.074
0.044
0.026
0.015
0.009
0.005
20 30
Field Data from Site
l
—No Degradation/Production
1.20
J 1.00
E 0.80
c
0.60
c�
0.40
aD
0.20 -
0
U 0.00
0 100
Monitoring Well Locations (ft)
215 450
-Sequential 1st Order Decay a Field Data from Site
200 300 400 500
Distance From Source (ft.)
600
600
700
See PCE
See TCE
See DCE
See VC
See ETH
Time:
20.0 Years Return to
Replay To All To Array
Log <�:�Linear Input

City of Winston-Salem I Hanes Mill Road Sanitary Landfill ���
Monitored Natural Attenuation Effectiveness Report

City of Winston-Salem I Hanes Mill Road Sanitary Landfill ���
Monitored Natural Attenuation Effectiveness Report
This page intentionally left blank.

C01►►►&I
400
350
� 300
w 250
.........
.0 200
...............
ru 150
—
.
100
...................
C 50
u 0
-50
Q7
O
O
r-1
O
ri
r-I
r-1
r-I
ri
N
r-1
N
ri
M
r-1
M
ri
r-1
ri
u'y
r-1
u']
ri
CD
r-I
CD
r-I
I�
r-1
n
ri
r-1
ri
Q7
r-1
Q7
ri
O
N
O
N
r-I
N
r-I N
N N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O
N
O O
N N
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
Dates
Tetrachloroethene
cis-1,2-Dichi oroethene
Vinyl chloride
......••• Linear {cis-1,2-Dichloroethene}
......••• Linear {Vinyl chloride}
400
350
J
300
250
C
0
+� 200
m
a)
150
V
0 100
U
50 -
0
C/1►ITS]
Trichloroethene
trans- 1,2-Dichloroethene
......••• Linear {Trichloroethene}
......••• Linear {cis-1,2-Dichloroethene}
O r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I N N N N N
O O O O O O O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N N N N N N N
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
Dates
cis-1,2-Dichloroethene Vinyl chloride
......••• Linear {cis-1,2-Dichloroethene} Rz = 0.4691 ......••• Linear (Vinyl chloride) Rz = 0.0041

C01►►►&I
40
35
30
J
nod 25
20
0
+� 15
r�
a)
10
C 5
0
U
0
m O O r-I r-I N N M M t t N Ln tD tD f-- r� CO CO a) a) - D -. , O r-I r N
O rl r-I rl r-I rl rl rl r-I r-I r-I r-I r-I r-I rl rl r-I rl rl rl rl N ?'V •.. N N
-5 O O O O O O O O O O O O O O O O o O O O O O O •o,_ O
N
10 N N N N N N N N N N N N N N N N N N N N N
O- �� �'O � �_O�� �� �� � �N �N 'ON "N
rq rq rq r-i r-i r-i r-i
Tetrachloroethene
trans- 1,2-Dichloroethene
......••• Linear (Trichloroethene) RI = 0.5805
Dates
Trichloroethene
......••• Linear (Tetrachloroethene) Rz = 0.3951
......••• Linear {trans-1,2-❑ichloroethene) Rz = 0.2368
ISATQ
40
35
..................
30
20
...................
10
5
0
U p
Q7
O
O
r-I
r-I
N
N
M
M
�
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N
Lf'] CD
CD
I�
n
DD
W
67
67
O
p
rl
rl N
O
p
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I r-I
O O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
r-I
O
N
O
N
O
N
O
N N
O O
N
N
N
N
N
N
N
N
N
N
N
N
N N
N
N
N
N
N
N
N
N
N
N
N N
_-
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r'I
r_I
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r_-I
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r_
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O
O
O
8-
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OO
O
O
8-
O
8-
8-
8- 4
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
Dates
Tetrachloroethene
cis-1,2-Dichi oroethene
Vinyl chloride
......••• Linear {Trichloroethene}
......••• Linear {trans-1,2-Dichloroethene}
Trichloroethene
trans- 1,2-Dichloroethene
......••• Linear (Tetrachloroethene)
......••• Linear {cis-1,2-Dichloroethene}
......••• Linear {Vinyl chloride}

OW-4
40
35
� 30
Ln 25
0 20 ....... —
15 — —
c 10 — —
u5 .... ...
....... 0
a) O O r-I r-I N N ro ro � � Ln Ln Co Co I- n 00 00 m a) O O r-I r-I N
O r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I N N N N N
O O O O O O O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N N N N N N N
4
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
OO O OO OO OO OO O O O O OO OO OO 4
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
Dates
Tetrachloroethene
cis-1,2-Dichloroethene
......••• Linear {Trichloroethene} Rz = 0.3831
OW-4
3
2.5
J
2
C
0
m
d 1
C
0
u 0.5
Trichloroethene
......••• Linear (Tetrachloroethene) Rz = 0.3685
......••• Linear {cis-1,2-Dichloroethene} Rz = 0.8048
0 r v It.
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O O O O O O O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N N N N N N N
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
O OO OO OO OO OO O O O O O OO OO 4
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
Dates
trans- 1,2-Dichloroethene Vinyl chloride
......••• Linear {trans-1,2-Dichloroethene} Rz = 0.6294 ......••• Linear (Vinyl chloride) Rz = 0.4971

Ow-1OD
PAP
J 20
15
Ln
..
10
c07, 5 ::::::..• .... ... .....
0
U 0
m O O r-I r-I N N rn M t � Ln Ln Co Co n n w w m m O O r-I r-I N
O r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I N N N N N
0 CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD O CD CD CD CD CD
N N N N N N N N N N N N N N N N N N N N N N N N N N
OO O O O O OO OO OO OO O O OO aO
r-I r-I r-I r-I r-I r-I r-I r-I r-I
Date
Tetrachloroethene
cis-1,2-Dichloroethene
Vinyl chloride
......••• Linear {Trichloroethene}
......••• Linear {trans-1,2-Dichloroethene}
PAP
20
QW-1OD
Trichloroethene
trans- 1,2-Dichloroethene
......••• Linear (Tetrachloroethene)
......••• Linear {cis-1,2-Dichloroethene}
......••• Linear {Vinyl chloride}
15 •• •• � �• r 1
10
0 5 ..• •
r,
0
O r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I N N N N N
O O O O O O O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N N N N N N N
r_-I r�-I r_-I r--I r_-I r-I r_-I r'I r_-I r'I r_-I r-I
O O O OO O O O O O O O OO O
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
Dates
Tetrachloroethene Trichloroethene
cis-1,2-Dichi oroethene ......••• Linear (Tetrachloroethene) Rz = 0.0062
......••• Linear {Trichloroethene} Rz = 0.4115 ......••• Linear {cis-1,2-Dichloroethene} Rz = 0.5414

Ow-10D
1.4
1.2
J 1
0.8
N
C
O
+� 0.6
m
d 0.4
V
C
u 0.2
0
O r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I N N N N N
0.20N N O O O O O O O O O O O O O O O O O O O O O O O O
_q � � � � � �
o o o o o Oo o o o o o o o
r-i r-i rq rq rq rq rq rq r-i r-i
Dates
trans- 1,2-Dichloroethene Vinyl chloride
......••• Linear {trans-1,2-Dichloroethene} Rz = 0.1137 ......••• Linear (Vinyl chloride) Rz = 0.2446
OW-17D
30
J
25
20 ........
0 15 ....
a 10 .
d
5 LIu9%%L.t . .....
C 0
O a) O O -i -i N N M rn � �t Ln Ln LD LD 1� I-- CO CO m m O O r-i r-i N
U -5 O r-I r-i r-I r-i r-I r-i r-I r-i r-I r-I r-I r-i r-I r-i r-I r-i r-I r-i r-I r-i N N N N N
O O O O O O O O O O O O O O O O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N N N N N N N
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-i r-I r-I r-I
O O O OO O O O O O O O OO O
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-i r-I
Dates
Tetrachloroethene
cis-1,2-Dichi oroethene
—Vinyl chloride
•••• Linear (Trichloroethene)
•••• Linear {cis-1,2-Dichloroethene}
•••• Linear {Vinyl chloride}
Trichloroethene
trans- 1,2-Dichloroethene
......••• Linear (Tetrachloroethene)
......••• Linear {cis-1,2-Dichloroethene}
......••• Linear {trans-1,2-Dichloroethene}

Ow-17 D
9101
25
J
Q
20
.v
15
c
c 10 .... .. ........
U 5 :..
0
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O r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I N N N N N
O O O O O O p O p O p O p O p O O O O O O O O O O O
N N N N N N N N N N N N N N N N N N N N N N N N N N
r_I r'I r--I r r--I r-I r_-I r'I -r-I r'I r_-I r'I
O O O O OO OO O O O O O OO OO 4
r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I r-I
Dates
Trichloroethene
......••• Linear {Trichloroethene} Rz = 0.1891
ISITITSWA11
cis-1,2-Dichloroethene
......••• Linear (cis-1,2-Dichloroethene)Rz=0.7082
3.5
—
3
2.5
—
in
2
C
0
+�
1.5
r�
.......
....
1
...
...=
.../......,
0
0.5
.*.
:_...
u
......
0,00.....
........
...........
0
m • • . CS• • • •0 •
• r-I •
r-I
N
N
ro
ro
It
�
Lr]
u']
Co
Co
rI_
n
00
00
a)
a)
CD
O
r-I
r-I N
CDr-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
N
N
N
N N
-0.5
O
N
p
N
O
N
O
N
p
N
p
N
p
N
p
N
p
N
O
N
O
N
O
N
p
N
p
N
p
N
0
N
p
N
O
N
O
N
O
N
O
N
O
N
O
N
p
N
p O
N N
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I
r-I r-I
O
O
O
OO
OO
OO
OO
O
O
OO
OO
OO
O
r-I
r-I
r-I
r-I
r-I
r-I
r-I
Dates
Tetrachloroethene trans- 1,2-Dichloroethene
Vinyl chloride ......••• Linear (Tetrachloroethene) Rz = 0.0589
......••• Linear (trans-1,2-Dichloroethene) 2 = 0.1783 ""..... Linear {Vinyl chloride} Rz = 0.3674