1107_Buncombe_MSWLF_CDLF_MonitoringRequest_FID1416459_20200619

REPORT OF 1,4-DIOXANE
SAMPLING AND ANALYSIS
NOVEMBER 2018
TO APRIL 2020
BUNCOMBE COUNTY LANDFILL
ALEXANDER, NORTH CAROLINA
Permit No. 1107-MSWLF-1996
Permit No. 1107-CDLF-1998
Prepared For:
Buncombe County
BLE Project Number J20-9378-20
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IM 13UNNELL
M LAMMONS
ENGiNEERTNG
6004 Ponders Court I Greenville, 5C 29615
864-288.1265 A 864,286.4330 w info@hle[orp.com
BLECORMOM

� CANNONS
ENGINEERING
June 19, 2020
Buncombe County Solid Waste Department
81 Panther Branch Road
Alexander, North Carolina 28701
Attention: Ms. Kristy Smith
Subject: Report of 1,4-Dioxane Sampling and Analysis
November 2018 to April 2020
Buncombe County Landfill
Alexander, North Carolina
Permit Nos. 1107-MSWLF-1996 & 1107-CDLF-1998
BLE Project Number J20-9378-20
Dear Ms. Smith:
At the request of Buncombe County, Bunnell-Lammons Engineering, Inc. (BLE) has prepared this report of
the 1,4-dioxane sampling and analysis results for the period from November 2018 to April 2020 at the
Buncombe County Landfill. Consistent with the North Carolina Division of Waste Management (DWM) —
Solid Waste Section (SWS) approved monitoring program, sampling and analysis has included analysis of 1,4-
dioxane in sampling events performed after May 2018. This report contains the information required by the
SWS to address the 1,4-dioxane detected at the facility and to determine an appropriate course of action for
regulatory compliance and future monitoring.
Sincerely,
BUNNELL LAMMONs ENGINEERING INC.
Timothy J. Daniel, P.G.
Staff Hydrogeologist
Registered, NC #2653
cc: Ms. Jaclynne Drummond — DWM-ARO
94/
Andrew W. Ale der, P.G., RSM
Senior Hydrogeologist
Registered, NC #1475
Ilblegvlsvrllsolidwasteprojectslbuncombe county lf, nc19378-20 spring 2020 semi reportll,4-dioxane submittandioxane report bcoactive bclf
1107-mswlf-1996 2020 dioxane report 9378-20.docx
6004 Ponders Court, Greenville, SC 29615 ILH64.288.1265 1-2�864.288.4430 P—[e-mail]
BLECORP.COM

1s 1m 1i
Buncombe County Landfill -- Alexander, North Carolina June 19, 2020
Report of 1,4-Dioxane Sampling and Analysis — November 2018 to April 2020 BLE Project No. J20-9378-20
TABLE OF CONTENTS
1.0 PROJECT INFORMATION........................................................................................................1
2.0 RESULTS....................................................................................................................................... 2
2.1 Groundwater.................................................................................................................................... 2
2.2 Surface Water.................................................................................................................................. 2
2.3 Leak Detectors and Leachate Samples............................................................................................. 2
3.0
CONCLUSIONS AND RECOMMENDATIONS....................................................................... 3
3.1
Groundwater.................................................................................................................................... 3
3.2
Surface Water.................................................................................................................................. 3
3.3
Leak Detectors and Leachate Samples............................................................................................. 3
3.4
Continued Analysis.......................................................................................................................... 3
4.0 QUALIFICATIONS OF REPORT.............................................................................................. 4
5.0 CLOSING.......................................................................................................................................4
Tables
Table lA SWS Approved Sampling Matrix
Table 113 Proposed Sampling Matrix
Table 2 Summary of 1,4-Dioxane in Groundwater
Table 3 Summary of 1,4-Dioxane in Surface Water
Table 4 Summary of 1,4-Dioxane in Leak Detectors and Leachate
Figures
Figure 1 Site Location Map
Figure 2 Map of 1,4-Dioxane Detections -- 11-29-2018 to 4-27-2020
Appendices
Appendix A SWS Memorandum — 1,4-Dioxane Analysis, Solid Waste Section Limits, and Laboratory
Analytical Methods (May 29, 2018)
iofi

1s 1m 1i
Buncombe County Landfill -- Alexander, North Carolina June 19, 2020
Report of 1,4-Dioxane Sampling and Analysis - November 2018 to April 2020 BLE Project No. J20-9378-20
1.0 PROJECT INFORMATION
The subject 654-acre landfill site is located in Buncombe County, North Carolina, approximately nine miles
north of the city of Asheville with a physical address of 81 Panther Branch Road in Alexander, North Carolina
(Figure 1). Buncombe County owns and operates a Subtitle D MSWLF which includes Cell 1 through Cell
6 and a CDLF consisting of Phase 1 through Phase 6. Currently Cell 6 of the MSWLF and Phase 6 of the
CDLF are the active waste units. MSWLF Cell 7 has been permitted for construction and MSWLF Cells 8
through 10 are planned (but not permitted) for future expansion.
A Water Quality Monitoring Plan (WQMP) was finalized by BLE and submitted to the North Carolina Solid
Waste Section (SWS). The WQMP was approved on January 2, 2018 (DIN 28513). The facility requires
semi-annual groundwater, surface water, and leachate monitoring and reporting in accordance with the
WQMP. Semi-annual sampling is typically conducted each April and October and those events are designated
"Spring" and "Fall," respectively.
The existing groundwater monitoring network for the Buncombe County Landfill consists of two (2)
upgradient (background) wells (MW-1 and MW-lD) and twenty-five (25) downgradient (compliance) wells
(MW-2, MW-2D, MW-3R, MW-4, MW-4D, MW-5, MW-5D, MW-6, MW-7, MW-8, MW-8D, MW-10,
MW-10D, MW-11, MW-11D, MW-12, MW-12D, MW-13, MW-13D, MW-14, MW-14D, MW-15, MW-
15D, MW-17, and MW-17D).
In accordance with Rule .0602 and Rule .0544(c), eight (8) surface water monitoring locations have been
established for the facility to monitor surface water quality surrounding the existing waste footprint. The
existing surface water locations consist of one (1) upstream (background) point (SW-1) and seven (7)
downstream (compliance) points (SW-2 through SW-8).
In accordance with Rule .1626(12)(c), eight (8) active leachate sampling locations have been established for
the facility. The locations include six (6) existing leak detection sampling locations associated with each
MSWLF cell (Cells 1 through 6) designated LD-1 through LD-6, one (1) leachate leak detection sampling
location near the leachate pond designated Leachate LD, and the Leachate Pond itself.
Groundwater, surface water, and leachate samples were collected and analyzed by Pace Analytical Services,
LLC. (Pace) of Huntersville, North Carolina prior to March 2020. Beginning in April 2020 analytical services
were moved to Pace's Columbia, South Carolina laboratory (former Shealy Environmental). Sampling and
analysis has been performed in general accordance with the SWS approved matrix (Table IA).
The SWS issued a memo on May 29, 2018 (Appendix A) which included a requirement for the sampling,
analysis, and reporting of 1,4-dioxane at all facilities. Therefore, the subject site has had four (4) events where
sampling for 1,4-dioxane should have occurred (November 2018, April 2019, November 2019, and April
2020).
The reports of the November 2018 and April 2019 events were prepared by SCS Engineers. BLE prepared
and submitted a report of the Fall 2019 sampling event titled Report of Water Quality Sampling and Analysis
2nd Semi Annual Event 2019 dated May 5, 2020 (BLE Project J19-9378-19). The report documented the
results of the sampling events conducted in November 2019, et seq. The Spring 2020 sampling event (1st
Semi -Annual Event 2020) was performed in April 2020. Those data are currently in review and the results
will be published in a report under separate cover. This report includes the unpublished 1,4-dioxane results
from the April 2020 sampling event.
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Buncombe County Landfill -- Alexander, North Carolina June 19, 2020
Report of 1,4-Dioxane Sampling and Analysis — November 2018 to April 2020 BLE Project No. J20-9378-20
2.0 RESULTS
2.1 Groundwater
The results of the groundwater 1,4-dioxane laboratory analyses are summarized on Table 2 and are shown
graphically on Figure 2. There is at least one detection of 1,4-dioxane in MW-41), MW-10, MW-12, MW-15,
and MW-15D over the four (4) sampling events from November 2018 to April 2020. It is noted that monitoring
wells MW-17 and MW-17D are new wells and have only been sampled twice with no detections of 1,4-
dioxane. It is also noted that 1,4-dioxane has been detected in MW-15D three of four events and those
concentrations exceed the North Carolina Groundwater Quality Standards (NC2L) maximum contaminant
level' (MCL) of 3.0 µg/L. There is no consistent concentration value in any of these wells where 1,4-dioxane
is detected. The results appear highly variable.
2.2 Surface Water
The results of the surface water 1,4-dioxane laboratory analyses are summarized on Table 3 and are shown
graphically on Figure 2. There is at least one detection of 1,4-dioxane in SW-3, SW-4, SW-5, SW-6, SW-7,
and SW-8 over the four (4) sampling events from November 2018 to April 2020. It is noted that monitoring
point SW-8 is new and has only been sampled twice with detections of 1,4-dioxane both times. It is also noted
that 1,4-dioxane has been detected in SW-3 four of four events. Only one detected concentration in SW-4 (81.3
µg/L) exceeds the North Carolina Surface Water Quality Standards (NC2B)2 standard limit of 80.0 µg/L.
There is no consistent concentration value in any of these surface water points where 1,4-dioxane is detected.
The results appear highly variable.
2.3 Leak Detectors and Leachate Samples
The results of the leak detectors and leachate 1,4-dioxane laboratory analyses are summarized on Table 4 and
are shown graphically on Figure 2. There is at least one detection of 1,4-dioxane in LD-1, LD-4, and in the
Leachate Pond over the four (4) sampling events from November 2018 to April 2020. It is noted that the SWS
does not require sampling of the leachate pond for 1,4-dioxane (Appendix A) and therefore we are unsure why
this analysis was performed in November 2018, April 2019, and November 2019. It is also noted that the SWS
does not require sampling of the leak detectors or leachate LD for 1,4-dioxane (Appendix A) and therefore we
are unsure why this analysis was performed.
Concentrations of 1,4-dioxane has been detected in LD-1 four of four events and in LD-4 three of four events.
A NC2L standard has not been established for leak detectors or leachate so we have shown the NC2L
groundwater standard on Table 4 for reference. There is no consistent concentration value in any of these leak
detectors where 1,4-dioxane is detected. The results appear highly variable.
' North Carolina Department of Environmental Quality, Classifications of Water Quality Standards, Section 15A NCAC 2L.202, April 1, 2013.
2 North Carolina Department of Environmental Quality, Surface Waters and Wetlands Standards, Section 15A NCAC 02B workbook dated June
10, 2019.
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Buncombe County Landfill -- Alexander, North Carolina June 19, 2020
Report of 1,4-Dioxane Sampling and Analysis — November 2018 to April 2020 BLE Project No. J20-9378-20
3.0 CONCLUSIONS AND RECOMMENDATIONS
We understand that the SWS has determined that if a monitoring point has had three (3) consecutive
sampling events with no detections of 1,4-dioxane; then the requirement for 1,4-dioxane may be removed
for that point. We understand that this is an informal and unpublished policy and subject to change. We
will utilize this policy in our recommendations below.
3.1 Groundwater
The groundwater 1,4-dioxane data indicates 1,4-dioxane is consistently not present (not detected) at several
locations. Therefore, we recommend that 1,4-dioxane analyses be discontinued for seventeen (17) wells as
shown in blue on the Proposed Sampling Matrix (Table 113). We recommended continued analysis of 1,4-
dioxane at ten (10) wells (Table 113). These ten wells include four well pairs where 1,4-dioxane has been
detected in one well but not the other. We recommend continued analysis in some of these well pairs due to
geographic proximity of detections (Figure 2). It is noted that continued analysis in the MW-17/1\4W-17D
well pair is recommended because these two wells have only been sampled twice. If 1,4-dioxane is not detected
in the next sampling event, then the analysis requirement should be removed.
3.2 Surface Water
The surface water 1,4-dioxane data indicates that 1,4-dioxane has been detected at every location except SW-
1 and SW-2 (Table 3). We recommend continued analysis at every surface water location (Table 113) due to
geographic proximity of detections (Figure 2).
3.3 Leak Detectors and Leachate Samples
We recommend that 1,4-dioxane analyses continue on an annual basis at the LD-5 monitoring point and be
discontinued at all of the remaining monitoring points as shown in blue on the Proposed Sampling Matrix
(Table 113).
3.4 Continued Analysis
The results ofthe groundwater 1,4-dioxane laboratory analyses for all monitoring points summarized on Tables
2, 3, and 4 appear highly variable. There is no consistent concentration value in any of these monitoring points
where 1,4-dioxane is detected. For example, it is apparent from the data (such as the result in surface water
sample location SW-4 of 81.3 µg/L) that the detected concentration value is not valid data. We understand that
these differences in concentration may be due to many factors including method performance as the result of a
change from EPA Method 8260B SIM to EPA Method 8260D SIM beginning in April 2019. Additionally, as
previously noted, beginning in April 2020 analytical services were moved to from Pace Huntersville to Pace
Columbia (former Shealy Environmental).
We can conclude two things from these data. That 1,4-dioxane is not present at locations where it is
consistently non -detect and 1,4-dioxane is possibly present where it has been detected at least once. The
graphical distribution of the detections (Figure 2) appears to validate this hypothesis.
Therefore, we recommend that analysis of 1,4-dioxane continue as specified on Table 113 at the Pace
Columbia laboratories until consistent data can be obtained for regulatory decision making.
3 of 4

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Buncombe County Landfill -- Alexander, North Carolina June 19, 2020
Report of 1,4-Dioxane Sampling and Analysis — November 2018 to April 2020 BLE Project No. J20-9378-20
4.0 QUALIFICATIONS OF REPORT
The activities and evaluative approaches used in this assessment are consistent with those normally employed
in hydrogeological and environmental assessments of this type. Our evaluation of site conditions has been
based on our understanding of the site and project information and the data provided to BLE.
This report has been prepared on behalf of and exclusively for the use of Buncombe County, North Carolina.
This report and the findings contained herein shall not, in whole or in part, be used or relied upon by any other
party (excluding the DWM) without BLE's prior written consent.
5.0 CLOSING
We appreciate the opportunity to be of service to Buncombe County, North Carolina. Please contact us at
[phone] if you have any questions or comments.
4 of 4

Tables

Table IA
SWS Approved Sampling Matrix
Buncombe County Landfill
Permit No. 1107-CDLF-1998
Permit No. 1107-MSWLF-1996
Alexander, North Carolina
BLE Project Number J20-9378-20
April
October
*Analytical Suite*
*Analytical Suite*
Station ID
a
MW-1
A-1 Plus
A-1 Plus
x �
V
MW-ID
A-1 Plus
A-1 Plus
MW-2
A-1
A-1
MW-21)
A-1
A-1
MW-3R
A-1
A-1
MW-4
A-1
A-1
MW-41)
A-1
A-1
MW-5
A-1
A-1
MW-5D
A-1
A-1
MW-6
A-1
A-1
MW-7
A-1
A-1
MW-8
A-1
A-1
MW-8D
A-1
A-1
MW-10
A-1
A-1
d
MW-10D
A-1
A-1
r
"
MW-11
A-1
A-1
O
U
MW-11D
A-1
A-1
MW-12
A-1 Plus
A-1 Plus
MW-12D
A-1 Plus
A-1 Plus
MW-13
A-1
A-1
MW-13D
A-1
A-1
MW-14
A-1 Plus
A-1 Plus
MW-14D
A-1 Plus
A-1 Plus
MW-15
A-1 Plus
A-1 Plus
MW-15D
A-1 Plus
A-1 Plus
MW-16
A-1
A-1
MW-16D
A-1
A-1
MW-17
A-1 Plus
A-1 Plus
MW-17D
A-1 Plus
A-1 Plus
SW-1
A-1
A-1
SW-2
A-1
A-1
SW-3
A-1
A-1
d
w
SW-4
A-1
A-1
L
7
SW-5
A -IT
A -IT
SW-6
A -IT
A -IT
SW-7
A-1
A-1
SW-8
A -IT
A-1T
LD-1
A-1
A-1
y
LD-2
A-1
A-1
0
LD-3
A-1
A-1
Ca
LD-4
A-1
A-1
v
a
LD-5
A-1
A-1
b
d
LD-6
A-1
A-1
R
N
LD-7
A-1
A-1
F�
Leachate LD
A-1
A-1
Leachate Pond
LMP
LMP
Notes:
A-1 = Appendix I VOCs plus 1,4-Dioxane & Metals
A -IT = Appendix I VOCs plus Tetrahydrofuran, 1,4-Dioxane, & Metals
A-1 Plus = Appendix I VOCs plus Tetrahydrofuran, 1,4-Dioxane,
& Metals plus Mercury, Manganese, Iron, Sulfate, Chloride,
Alkalinity, & Total Dissolved Solids
IMP (Leachate Monitoring Parameters) = Appendix I VOCs & Metals, pH,
specific conductance, BOD, COD, Nitrates, Sulfates, & Phosphates.
LD = Leak Detector
Do Not Exist - Permitted for Future MSWLF Cell 7
Table revised July 16, 2019 (SW-8 and 1,4-dioxane)
Table revised February 27, 2020 (BLE Project No. 9378-20 for Spring 2020)
Prepared by: AWA
Checked by: MSP
\\BLEGVLSVRI\SolidWasteProjects\Buncombe County LF, NC\9378-20 Spring 2020 Semi Report\1,4-dioxane Submittal\Dioxane Report BCLF\Active BCLF 1,4-dioxane Summaryxlsx

Table 1B
Proposed Sampling Matrix
Buncombe County Landfill
Permit No. 1107-CDLF-1998
Permit No. 1107-MSWLF-1996
Alexander, North Carolina
BLE Project Number J20-9378-20
April
October
Station ID
*Analytical Suite*
1,4-Dioxane
*Analytical Suite*
1,4-Dioxane
a
y y
MW-1
A-1 Plus
A-1 Plus
0.1
NM -ID
A-1 Plus
A-1 Plus
NM-2
A-1
A-1
MW-21)
A-1
A-1
NM-3R
A-1
A-1
NM-4
A-1
yes
A-1
yes
MW-41)
A-1
yes
A-1
yes
MW-5
A-1
A-1
MW-51)
A-1
A-1
MW-6
A-1
A-1
MW-7
A-1
A-1
MW-8
A-1
A-1
MW-81)
A-1
A-1
MW-10
A-1
yes
A-1
yes
C
MW-lOD
A-1
yes
A-1
yes
R y
E
MW-11
A-1
A-1
0
U
NM-11D
A-1
A-1
NM-12
A-1 Plus
yes
A-1 Plus
yes
NM-12D
A-1 Plus
yes
A-1 Plus
yes
NM-13
A-1
A-1
MW-13D
A-1
A-1
NM-14
A-1 Plus
A-1 Plus
NM-14D
A-1 Plus
A-1 Plus
MW-15
A-1 Plus
yes
A-1 Plus
yes
NM-15D
A-1 Plus
yes
A-1 Plus
yes
NM-16
A-1
yes
A-1
yes
MW-16D
A-1
yes
A-1
yes
MW-17
A-1 Plus
yes
A-1 Plus
yes
MW-17D
A-1 Plus
yes
A-1 Plus
yes
SW-1
A-1
yes
A-1
yes
SW-2
A-1
yes
A-1
yes
SW-3
A-1
yes
A-1
yes
SW-4
A-1
yes
A-1
yes
e
�'
SW-5
A-1T
yes
A -IT
yes
SW-6
A -IT
yes
A-1T
yes
SW-7
A-1
yes
A-1
yes
SW-8
A -IT
yes
A-1T
yes
LD-1
A-1
A-1
LD-2
A-1
A-1
e
LD-3
A-1
A-1
A
LD-4
A-1
A-1
R
LD-5
A-1
A-1
yes
LD-6
A-1
A-1
LD-7
A-1
A-1
u
a
Leachate LD
A-1
A-1
ILMP
I
ILMP
Leachate Pond
Notes:
A-1 = Appendix I VOCs & Metals
A-1T = Appendix I VOCs plus Tetrahydrofuran & Metals
A-1 Plus = Appendix I VOCs plus Tetrahydrofuran,
& Metals plus Mercury, Manganese, Iron, Sulfate, Chloride,
Alkalinity, & Total Dissolved Solids
LMP (Leachate Monitoring Parameters) = Appendix I VOCs & Metals, pH,
specific conductance, BOD, COD, Nitrates, Sulfates, & Phosphates.
LD = Leak Detector
Do Not Exist - Permitted for Future MSWLF Cell 7
1,4-Dioxane removed for these points
Table revised July 16, 2019 (SW-8 and 1,4-dioxane)
Table revised February 27, 2020 (BLE Project No. 9378-20 for Spring 2020)
Table revised June 19, 2020 (Change 1,4-Dioxane Matrix)
Prepared by: AWA
Checked by: TJD
\\BLEGVLSVRI\SolidWasteProjects\Buncombe County LF, NC\9378-20 Spring 2020 Semi Report\1,4-dioxane Submittal\Dioxane Report BCLF\Active BCLF 1,4-dioxane Summary.xlsx

Table 2
Summary of 1,4-Dioxane in Groundwater
Buncombe County Landfill
Alexander, North Carolina
BLE Project Number J20-9378-20
Permit No.1107-CDLF-1998
Permit No. 1107-MSWLF-1996
Compound:
1,4-Dioxane
NC2L (µg/1):
3.0
Method:
EPA 8260B/D SIM
Background:
MW-1/MW-ID
U
►a
A
A
Ri
A
A
A
O
O
'-I
A
N
N
M
M
R
e
N
A
H
n
A
ti
M
7
7
M
h
b
r`
00
Gorl
rl
rl
rl
rl
rl
rl
rl
Pre -May 2018
NT NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NT
NP
NP
11/29/18
1.9 2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
NP
NP
04/29/19
1.2 2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
4.2
NP
NP
11/15/19
2.0 2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
3.9
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
3.7
<2.0
<2.0
<2.0
3.2
<2.0
<2.0
<2.0
<2.0
<2.0
2.6
12.6
<2.0
<2.0
04/27/20
1.0 3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
<3.0
1.6 J
<3.0
<3.0
<3.0
<3.0
<3.0
2.3 J
21
<3.0
<3.0
Notes:
MDL = Method Detection Limit
MRL = Method Reporting Limit
J = values estimated between the MDL and the MRL
NT = Not Tested
NP = Not Present
NC2L = North Carolina Groundwater Standards, as established in the NCDENR, Classifications of Water Quality Standards Applicable
to Groundwaters of North Carolina, Section 15A NCAC 2L.202. Dated April 1, 2013.
Prepared by: TJD
Checked by: IAI
\\BLEGVLSVR1\SolidWasteProjects\Buncombe County LF, NC\9378-20 Spring 2020 Semi Report\1,4-dioxane Submittal\Dioxane Report BCLF\Active BCLF 1,4-dioxane Summary.xlsx

Table 3
Summary of 1,4-Dioxane in Surface Water
Buncombe County Landfill
Alexander, North Carolina
BLE Project Number J20-9378-20
Permit No.1107-CDLF-1998
Permit No. 1107-MSWLF-1996
Compound: 1,4-Dioxane
NC213 (µg/l): 80
Method: EPA 8260B/D SIM
Upstream: SW-1
C7
z
a
00
AUn
U3
Qn
U3
U3
U3
U3
U3
Pre -May 2018
NT
NT
NT
NT
NT
NT
NT
NT
NT
NP
11/29/18
1.9
2.0
<2.0
<2.0
18.7
<2.0
<2.0
<2.0
5.7
NP
04/29/19
1.2
2.0
<2.0
<2.0
11.1
<2.0
<2.0
16.1
<2.0
NP
11/15/19
2.0
2.0
<2.0
<2.0
51.5
81.3
<2.0
3.8
<2.0
12.7
04/27/20
1.0
3.0
<3.0
<3.0
3.4
1.9 J
4.1
5.3
<3.0
1.3 J
Notes:
MDL = Method Detection Limit
MRL = Method Reporting Limit
J = values estimated between the MDL and the MRL
NT = Not Tested
NP = Not Present
NC213 = North Carolina Surface Water Standards for Class C freshwater under Title 15A Subchapter 213.
per NC DWR Surface Water Quality Standards, Criteria, & In -Stream Target Values (Workbook Dated 6-10-2019)
Prepared by: TJD
Checked by: IAI
\\BLEGVLSVRI\SolidWasteProjects\Buncombe County LF, NC\9378-20 Spring 2020 Semi Report\1,4-dioxane Submittal\Dioxane Report
BCLF\Active BCLF 1,4-dioxane Summary.xlsx

Table 4
Summary of 1,4-Dioxane in Leak Detectors and Leachate
Buncombe County Landfill
Alexander, North Carolina
BLE Project Number J20-9378-20
Permit No. 1107-CDLF-1998
Permit No. 1107-MSWLF-1996
Compound: 1,4-Dioxane
NC2L (µg/l): 3.0
Method: EPA 8260B/D SIM
Background: MW-1/MW-ID
C7 c
Z A 0.
a� v
Q+ W a a H N M R \O U U
A a C� CC
H
Pre -May 2018 NT NT NT NT NT NT NT NT NT NT
11/29/18 1.9 2.0 2.7 <2.0 <2.0 16.4 <2.0 <2.0 <2.0 21.3
04/29/19 1.2 2.0 14.4 <2.0 <2.0 22.2 <2.0 <2.0 <2.0 16.1
11/15/19 2.0 2.0 17.4 <2.0 <2.0 5.9 <2.0 <2.0 <2.0 26.8
04/27/20 1.0 3.0 12.0 <3.0 <3.0 <3.0 <3.0 <3.0 <3.0 NT
Notes:
MDL = Method Detection Limit
MRL = Method Reporting Limit
J = values estimated between the MDL and the MRL
NT = Not Tested
NP = Not Present
NC21, = North Carolina Groundwater Standards, as established in the NCDENR, Classifications of Water Quality Standards Applicable
to Groundwaters of North Carolina, Section 15A NCAC 2L.202. Dated April 1, 2013.
Prepared by: TJD
Checked by: IAI
\\BLEGVLSVRI\SolidWasteProjects\Buncombe County LF, NC\9378-20 Spring 2020 Semi Report\1,4-dioxane Submittal\Dioxane
Report BCLFWctive BCLF 1,4-dioxane Summary.xlsx

Figures

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DRAWN: KLW DATE. 6-10-20
' IM I BUNNELL
� LAMMONS
CHECKED: AWA CAD: BCLF20-SLM ENGINEERING
6004 Ponders Court, Greenville, SC 29615
APPROVED: AWA JOB NO: J20-9378-20 Phone: [phone] Fax: (864] 288-4430
REFERENCE:
USGS TOPOGRAPHIC MAP, 7.5 MINUTE SERIES,
LEICESTER AND WEAVERVILLE, N.C. QUADRANGLES,
PHOTOREMSED 2017 AND PHOTOREMSED 2017.
SITE LOCATION MAP I
BUNCOMBE COUNTY LANDFILL
ALEXANDER, NORTH CAROLINA
FIGURE

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1 PHASE \ � � POND EMPLOYEE
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REVISIONS
No. DESCRIPTION BY
DRAWN: KLW
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APPROVED: AWA
—1850
1830-
DATE: 6-5-20
CAD FILE: F2 BCLF20-DIOX
JOB NO: J20-9378-20
off_
4
a
>90
a
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*4t,
LEGEND
—1980 TOPOGRAPHIC CONTOUR
— — — — — WASTE UNIT BOUNDARY
� I I � FACILITY BOUNDARY
MW-10 EXISTING GROUNDWATER
MONITORING WELL
�MW- 16 PERMITTED FUTURE GROUNDWATER
MONITORING WELL
EXISTING SURFACE WATER
SW-2 MONITORING LOCATION
* LD-1 LEAK DETECTOR
* LD-7 PERMITTED FUTURE LEAK DETECTOR
0 M-3 EXISTING LANDFILL GAS MONITORING WELL
-OM-5 PERMITTED FUTURE LANDFILL GAS MONITORING WELL
REFERENCES:
1) SHEET NO. 1 GROUNDWATER AND METHANE MONITORING WELL
EXISTING STRUCTURE MONITORED FOR
LOCATIONS, CDM SMITH, PROJECT NO. 6447-105257. FILE: SITEMAP
■ LANDFILL GAS
2014.DWG.
M-8
2) SURFACE WATER LOCATIONS FROM SHEET NO. 1 GROUNDWATER
AND METHANE MONITORING WELL LOCATION MAP, CDM SMITH,
li� MW-15D MONITORING POINT WITH AT LEAST ONE
NOVEMBER 2012 PROJECT NO. 6447-93318. FILE: SITEMAP. DWG.
DETECTION OF 1,4-DIOXANE FROM
1 1-29-2018 TO 4-27-2020
3) PHASE 6 C&D BOUNDARY PROVIDED BY MCGILL.
4) SHEET NO. OP-1 EXISTING CONDITIONS, CDM SMITH, PROJECT NO.
6447-97693. FILE: OP-1.DWG.
5) FIGURE NO. 3-1 WATER QUALITY MONITORING PLAN CELL 6 AREA,
CDM, PROJECT NO. 6447, DATED NOVEMBER 2004.
6) SURVEY OF MW-17, MW-17D AND M-12 BY ED HOLMES AND
ASSOCIATES DATED JUNE 28, 2019
k CAq
�GENSF�.,->NOTES:
LOCATION ACCURACY
�rza QF' s \ o�, OF THE FEATURES
4L0°''P�,`' SHOWN IS LIMITED BY
1,w„10 THE REFERENCES
THEMSELVES.
is 1IM I BUNNELL
BUNNELL
ENGINEERING
6004 Ponders Court, Greenville, SC 29615
Phone; [phone] Fax; [phone]
MAP OF 1,4-DIOXANE DETECTIONS 11-29-2018 TO 4-27-2020
BUNCOMBE COUNTY LANDFILL
ALEXANDER, NORTH CAROLINA
200 100 0 200 400
APPROXIMATE SCALE IN FEET
FIGURE NO.
2

APPENDIX A
SWS Memorandum — 1,4-Dioxane Analysis, Solid
Waste Section Limits, and Laboratory Analytical
Methods (May 29, 2018)

ROY COOPER
Governor
K.1
MICHAEL S. REGAN � 0_
Waste Management MICHAEL SCOTTDirenu,
ENVIRONMENTAL QUALITY
May 29, 2018
MEMORANDUM
To: Solid Waste Directors, Landfill Owners/Operators, and North Carolina Certified
Laboratories
From: Ed Mussler, Section Chief
North Carolina Division of Waste Management, Solid Waste Section
Re: 1,4-Dioxane Analysis, Solid Waste Section Limits, and Laboratory Analytical
Methods
1,4-Dioxane Sampling
In accordance with 15A NCAC 13B .0601, .0544, and .1632, the Solid Waste Section (Section) is
requiring that all groundwater and surface water samples collected at landfills after July 1, 2018
be analyzed for the constituent 1,4-Dioxane. It is primarily used as a stabilizer for chlorinated
solvents, however also used in many products including paint strippers, dyes, greases, varnishes
and waxes. Additionally, it is found in a variety of consumer products such as detergents,
shampoos, deodorants, and cosmetics. The current 15A NCAC 02L .0202 Standard for 1,4-
Dioxane is 3.0 µg/1. Due to the potential health hazards associated with 1,4-Dioxane, the Section
has determined that all landfills should begin analyzing groundwater and surface water samples
for 1,4-Dioxane to ensure protection of human health and the environment. A USEPA Technical
Fact Sheet for 1,4-Dioxane is provided in Appendix A of this Memorandum.
Solid Waste Section Limits & Laboratory Analytical Methods
In 2006, the Solid Waste Section made a policy decision to develop and use Solid Waste Section
Limits (SWSLs). The purpose for this policy decision was to ensure that low level analytical data
was consistently being reported for the purpose of making the correct choices when designing site
remediation strategies, alerting the public to health threats, and protecting the environment from
toxic contaminants. Over the past 12 years, technologies have advanced such that the majority of
the SWSLs are outdated. Given the rapid pace of technology, the need for the Section to attempt
to continuously update and/or maintain the SWSLs is not warranted.
State of North Carolina I Environmental Quality I Waste Management
217 West ]ones Street 1 I646 Mail ServiCe Center I Raleigh, NOrth Carolina 27699-1646
9l9 707 8200

Although the use of the SWSLs will be discontinued, facilities should choose EPA approved
analytical methods sufficiently sensitive to quantify the presence of a pollutant at or below
applicable standards. Consistently achieving low level data is key for the continued purpose of
making the correct choices when designing site remediation strategies, alerting the public to health
threats, and protecting the environment from toxic contaminants. Facilities should communicate
and coordinate with their analytical laboratory(s) to use sufficiently sensitive analytical methods
to achieve analytical results with detection limits below the applicable groundwater standards and
surface water standards. For guidance purposes, the Section recommends the use of the following
analytical methods for groundwater and surface water samples.
Volatile Organic Compounds
SW 846 Method 8260
1,4-Dioxane
SW 846 Method 8260 SIM
SW 846 Method 8270 SIM
Semi -Volatile Organic
SW 846 Method 8270
Compounds
Metals, Pesticides, PCBs,
SW 846 Methods, USEPA
Dioxins, Cyanide,
methods, or method published
Formaldehyde, and any other
in Standard Methods for the
constituents not covered by
Examination of Water and
above methods
Wastewater having the lowest
detection limits or having
detection limits below
applicable standards
Notes:
• The analytical methods should be the most recent versions of the analytical methods
tabulated above. For SW- 846 Methods, the latest edition of SW-846, including any
subsequent updates which have been incorporated into the edition, must be used. Sampling
must be planned so that required holding times for analytical methods are met.
• Select Ion Monitoring (SIM) is recommended when analyzing for 1,4-Dioxane in order to
achieve applicable detection limits. SIM may be useful for other VOCs/SVOC constituents.
• SW-846 Method 1610 does not have detection limits below the 1 SA NCAC 2L standards
for all of the hazardous substance list metals.
• The Section considers "J" flag values valid and relevant in the decision making process
and hence all "J" flag values should be reported.
If you have any questions, please contact Adam Ulishney at [phone] or via email at
adam.ulishney&ncdenr.gov. Thank you for your cooperation in this matter.
State of North Carolina I Environmental Quality I Waste Management
217 West ]ones Street 1 I646 Mail ServiCe Center I Raleigh, North Carolina 27699-1646
9l9 707 8200

APPENDIX A
State of North Carolina I Environmental Quality I Waste Management
217 West ]ones Street 1 I646 Mail ServiCe Center I Raleigh, North Carolina 27699-1646
9l9 707 8200

■=. EPA
United States
Environmental Protection
Agency
Technical Fact Sheet —
1,4-Dioxane
January 2014
Introduction
This fact sheet, developed by the U.S. Environmental Protection Agency
(EPA) Federal Facilities Restoration and Reuse Office (FFRRO), provides a
summary of the contaminant 1,4-dioxane, including physical and chemical
properties; environmental and health impacts; existing federal and state
guidelines; detection and treatment methods; and additional sources of
information. This fact sheet is intended for use by site managers who may
address 1,4-dioxane at cleanup sites or in drinking water supplies and for
those in a position to consider whether 1,4-dioxane should be added to the
analytical suite for site investigations.
1,4-Dioxane is a likely human carcinogen and has been found in
groundwater at sites throughout the United States. The physical and
chemical properties and behavior of 1,4-dioxane create challenges for its
characterization and treatment. It is highly mobile and has not been shown
to readily biodegrade in the environment.
What is 1,4-dioxane?
❖ 1,4-Dioxane is a synthetic industrial chemical that is completely miscible
in water (EPA 2006).
❖ Synonyms include dioxane, dioxan, p-dioxane, diethylene dioxide,
diethylene oxide, diethylene ether and glycol ethylene ether
(EPA 2006; Mohr 2001).
❖ 1,4-Dioxane is unstable at elevated temperatures and pressures and
may form explosive mixtures with prolonged exposure to light or air
(DHHS 2011; HSDB 2011).
❖ 1,4-Dioxane is a likely contaminant at many sites contaminated with
certain chlorinated solvents (particularly 1,1,1-trichloroethane [TCA])
because of its widespread use as a stabilizer for chlorinated solvents
(EPA 2013a; Mohr 2001)
❖ It is used as: a stabilizer for chlorinated solvents such as TCA; a solvent
for impregnating cellulose acetate membrane filters; a wetting and
dispersing agent in textile processes; and a laboratory cryoscopic solvent
for molecular mass determinations (ATSDR 2012; DHHS 2011; EPA
2006).
❖ It is used in many products, including paint strippers, dyes, greases,
varnishes and waxes. 1,4-Dioxane is also found as an impurity in
antifreeze and aircraft deicing fluids and in some consumer products
(deodorants, shampoos and cosmetics) (ATSDR 2012; EPA 2006; Mohr
2001).
Disclaimer: The U.S. EPA prepared this fact sheet from publically-available
sources; additional information can be obtained from the source documents. This
fact sheet is not intended to be used as a primary source of information and is not
intended, nor can it be relied upon, to create any rights enforceable by any party
in litigation with the United States. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
United States Office of Solid Waste and EPA 505-F-14-011
Environmental Protection Agency Emergency Response (5106P) January 2014
1

What is 1,4-dioxane? (continued)
❖ 1,4-Dioxane is used as a purifying agent in the
manufacture of pharmaceuticals and is a by-
product in the manufacture of polyethylene
terephthalate (PET) plastic (Mohr 2001).
❖ Traces of 1,4-dioxane may be present in some
food supplements, food containing residues from
packaging adhesives or on food crops treated with
pesticides that contain 1,4-dioxane as a solvent or
inert ingredient (ATSDR 2012; DHHS 2011).
Exhibit 1: Physical and Chemical Properties of 1,4-Dioxane
(ATSDR 2012; Howard 1990; HSDB 2011)
Property
Value
Abstracts Service (CAS) Number
123-91-1
Physical Description (physical state at room temperature)
Clear, flammable liquid with a faint, pleasant
odor
Molecular weight (g/mol)
88.11
Water solubility
Miscible
Melting point (°C)
11.8
Boiling point (°C) at 760 mm Hg
101.1 °C
Vapor pressure at 25°C (mm Hg)
38.1
Specific gravity
1.033
Octanol-water partition coefficient (log Kow)
-0.27
Organic carbon partition coefficient (log Kos)
1.23
Henry's law constant at 25 °C (atm-m3/mol)
4.80 X 10-6
Abbreviations: g/mol — grams per mole; °C — degrees Celsius; mm Hg — millimeters of mercury;
atm-m3/mol — atmosphere -cubic meters per mole.
What are the environmental impacts of 1,4-dioxane?
❖ 1,4-Dioxane is released into the environment from surface water bodies (DHHS 2011; EPA
during its production, the processing of other 2006).
chemicals, its use and its generation as an
impurity during the manufacture of some
consumer products. It is typically found at some
solvent release sites and PET manufacturing
facilities (ATSDR 2012; Mohr 2001).
❖ It is short-lived in the atmosphere, with an
estimated 1- to 3-day half-life as a result of its
reaction with photochemically produced hydroxyl
radicals (ATSDR 2012; DHHS 2011). Breakdown
products include aldehydes and ketones (Graedel
1986).
❖ It may migrate rapidly in groundwater, ahead of
other contaminants and does not volatilize rapidly
❖ Migration to groundwater is weakly retarded by
sorption of 1,4-dioxane to soil particles; it is
expected to move rapidly from soil to groundwater
(EPA 2006; ATSDR 2012).
It is relatively resistant to biodegradation in water
and soil and does not bioconcentrate in the food
chain (ATSDR 2012; Mohr 2001).
As of 2007, 1,4-dioxane had been identified at
more than 31 sites on the EPA National Priorities
List (NPL); it may be present (but samples were
not analyzed for it) at many other sites (HazDat
2007).
What are the routes of exposure and the health effects of 1,4-dioxane?
❖ Potential exposure could occur during production Inhalation is the most common route of human
and use of 1,4-dioxane as a stabilizer or solvent exposure, and workers at industrial sites are at
(DHHS 2011). greatest risk of repeated inhalation exposure
Exposure may occur through inhalation of vapors, (ATSDR 2012; DHHS 2011).
ingestion of contaminated food and water or
dermal contact (ATSDR 2012; DHHS 2011).

What are the routes of exposure and the health effects of 1,4-dioxane?
(continued)
❖ 1,4-Dioxane is readily adsorbed through the
lungs and gastrointestinal tract. Some
1,4-dioxane may also pass through the skin, but
studies indicate that much of it will evaporate
before it is absorbed. Distribution is rapid and
uniform in the lung, liver, kidney, spleen, colon
and skeletal muscle tissue (ATSDR 2012).
❖ Short-term exposure to high levels of 1,4-
dioxane may result in nausea, drowsiness,
headache, and irritation of the eyes, nose and
throat (ATSDR 2012; EPA 2013b; NIOSH 2O10)
❖ Chronic exposure may result in dermatitis,
eczema, drying and cracking of skin and liver
and kidney damage (ATSDR 2012; HSDB
2011).
❖ 1,4-Dioxane is weakly genotoxic and
reproductive effects in humans are unknown;
however, a developmental study on rats
indicated that 1,4-dioxane may be slightly toxic
to the developing fetus (ATSDR 2012; Giavini
and others 1985).
❖ Animal studies showed increased incidences of
nasal cavity, liver and gall bladder tumors after
exposure to 1,4-dioxane (DHHS 2011; EPA IRIS
2013).
❖ EPA has classified 1,4-dioxane as "likely to be
carcinogenic to humans" by all routes of
exposure (EPA IRIS 2013).
❖ The U.S. Department of Health and Human
Services states that 1,4-dioxane is reasonably
anticipated to be a human carcinogen based on
sufficient evidence of carcinogenicity from
studies in experimental animals (DHHS 2011).
❖ The American Conference of Governmental
Industrial Hygienists (ACGIH) has classified
1,4-dioxane as a Group A3 carcinogen —
confirmed animal carcinogen with unknown
relevance to humans (ACGIH 2O11).
❖ The National Institute for Occupational Safety
and Health (NIOSH) considers 1,4-dioxane a
potential occupational carcinogen (NIOSH
2010).
Are there any federal and state guidelines and health standards for
1,4-dioxane?
❖ Federal and State Standards and Guidelines:
■ EPA's Integrated Risk Information System
(IRIS) database includes a chronic oral
reference dose (RfD) of 0.03 milligrams per
kilogram per day (mg/kg/day) based on liver
and kidney toxicity in animals and a chronic
inhalation reference dose (RfC) of 0.03
milligrams per cubic meter (mg/m3) based
on atrophy and respiratory metaplasia inside
the nasal cavity of animals (EPA IRIS 2013).
■ The Agency for Toxic Substances and
Disease Registry (ATSDR) has established
minimal risk levels (MRLs) for inhalation
exposure to 1,4-dioxane : 2 parts per million
(ppm) for acute -duration (14 days or less)
inhalation exposure; 0.2 ppm for
intermediate -duration (15 to 364 days)
inhalation exposure; and 0.03 ppm for
chronic -duration (365 days or more)
inhalation exposure (ATSDR 2012).
■ Oral exposure MRLs have been identified as
5 mg/kg/day for acute -duration oral
exposure; 0.5 mg/kg/day for intermediate -
duration oral exposure; and 0.1 mg/kg/day
for chronic -duration oral exposure (ATSDR
2012).
• The cancer risk assessment for 1,4-dioxane
is based on an oral slope factor of 0.1
mg/kg/day and the drinking water unit risk is
2.9 x 10-6 micrograms per liter (pg/L) (EPA
IRIS 2013).
■ EPA risk assessments indicate that the
drinkinP water concentration representing a
1 x 10- cancer risk level for 1,4-dioxane is
0.35 µg/L (EPA IRIS 2013).
■ 1,4-Dioxane may be regulated as hazardous
waste when waste is generated through use
as a solvent stabilizer (EPA 1996b).
■ No federal maximum contaminant level
(MCL) for drinking water has been
established; however, an MCL is not
necessary to determine a cleanup level
(EPA 2012).
■ 1,4-Dioxane was included on the third
drinking water contaminant candidate list,
which is a list of unregulated contaminants
that are known to, or anticipated to, occur in
public water systems and may require
regulation under the Safe Drinking Water
Act (EPA 2009).

Are there any federal and state guidelines and health standards for
1,4-dioxane? (continued)
❖ Federal and State Standards and Guidelines
(continued):
■ The EPA has established drinking water
health advisories for 1,4-dioxane, which are
drinking water -specific risk level
concentrations for cancer (10-4 cancer risk)
and concentrations of drinking water
contaminants at which noncancer adverse
health effects are not anticipated to occur over
specific exposure durations. The EPA
established a 1-day health advisory of 4.0
milligrams per liter (mg/L) and a 10-day health
advisory of 0.4 mg/L for 1,4-dioxane in
drinking water for a 10-kilogram child. EPA
also established a lifetime health advisory of
0.2 mg/L for 1,4-dioxane in drinking water
(EPA 2012).
■ The EPA's drinking water equivalent level for
1,4-dioxane is 1 mg/L (EPA 2012).
■ EPA has calculated a screening level of 0.67
pg/L for 1,4-dioxane in tap water, based on a
1 in 10-6 lifetime excess cancer risk (EPA
2013c). ' , 2
■ EPA has calculated a residential soil
screening level (SSL) of 4.9 milligrams per
kilogram (mg/kg) and an industrial SSL of 17
mg/kg. The soil -to -groundwater risk -based
SSL is 1.4 x10-4 mg/kg (EPA 2013c).
■ EPA has also calculated a residential air
screening level of 0.49 micrograms per cubic
meter (pg/m3) and an industrial air screening
level of 2.5 pg/m3 (EPA 2013c).
Screening Levels are developed using risk assessment guidance
from the EPA Superfund program. These risk -based concentrations
are derived from standardized equations combining exposure
information assumptions with EPA toxicity data. These calculated
screening levels are generic and not enforceable cleanup standards
but provide a useful gauge of relative toxicity.
2 Tap water screening levels differ from the IRIS drinking water
concentrations because the tap water screening levels account for
dermal, inhalation and ingestion exposure routes; age -adjust the
intake rates for children and adults based on body weight; and time -
adjust for exposure duration or days per year. The IRIS drinking
water concentrations consider only the ingestion route, account only
for adult -intake rates and do not time -adjust for exposure duration or
days per year.
❖ Workplace Exposure Limits:
■ The Occupational Safety and Health
Administration set a general industry
permissible exposure limit of 360 mg/m3 or 100
ppm based on a time -weighted average (TWA)
over an 8-hour workday for airborne exposure
to 1,4-dioxane (OSHA 2013).
■ The ACGIH set a threshold limit value of 72
mg/m3 or 20 ppm based on a TWA over an 8-
hour workday for airborne exposure to 1,4-
dioxane (ACGIH 2O11).
■ The NIOSH has set a ceiling recommended
exposure limit of 3.6 mg/m3 or 1 ppm based on
a 30-minute airborne exposure to 1,4-dioxane
(NIOSH 2O10).
■ NIOSH also has established an immediately
dangerous to life or health concentration of 500
ppm for 1,4-dioxane (NIOSH 2O10).
❖ Other State and Federal Standards and
Guidelines:
■ Various states have established drinking water
and groundwater guidelines, including the
following:
Colorado has established an interim
groundwater quality cleanup standard of
0.35 pg/L (CDPHE 2012);
California has established a notification
level of 1 pg/L for drinking water (CDPH
2011);
— New Hampshire has established a
reporting limit of 0.25 pg/L for all public
water supplies (NH DES 2011); and
— Massachusetts has established a drinking
water guideline level of 0.3 pg/L (Mass
DEP 2012).
• The Food and Drug Administration set 10
mg/kg as the limit for 1-4-dioxane in glycerides
and polyglycerides for use in products such as
dietary supplements. FDA also surveys raw
material and products contaminated with
1,4-dioxane (FDA 2006).
• 1,4-Dioxane is listed as a hazardous air
pollutant under the Clean Air Act (CAA) (CAA
1990).
■ A reportable quantity of 100 pounds has been
established under the Comprehensive
Environmental Response, Compensation, and
Liability Act (EPA 2011).

What detection and site characterization methods are available for
1,4-dioxane?
❖ As a result of the limitations in the analytical
methods to detect 1,4-dioxane, it has been difficult
to identify its occurrence in the environment. The
miscibility of 1,4-dioxane in water causes poor
purging efficiency and results in high detection
limits (ATSDR 2012; EPA 2006).
❖ Conventional analytical methods can detect
1,4-dioxane only at concentrations 100 times
greater than the concentrations of volatile organic
compounds (EPA 2006; Mohr 2001).
❖ Modifications of existing analytical methods and
their sample preparation procedures may be
needed to achieve lower detection limits for
1,4-dioxane (EPA 2006; Mohr 2001).
❖ High -temperature sample preparation techniques
improve the recovery of 1,4-dioxane. These
techniques include purging at elevated
temperature (EPA SW-846 Method 5030);
equilibrium headspace analysis (EPA SW-846
Method 5021); vacuum distillation (EPA SW-846
Method 8261); and azeotrophic distillation (EPA
SW-846 Method 5031) (EPA 2006).
❖ The presence of 1,4-dioxane may be expected at
sites with extensive TCA contamination; therefore,
some experts recommend that groundwater
samples be analyzed for 1,4-dioxane where TCA
is a known contaminant (Mohr 2001).
NIOSH Method 1602 uses gas chromatography —
flame ionization detection (GC-FID) to determine
the concentration of 1,4-dioxane in air. The
detection limit is 0.01 milligram per sample
(ATSDR 2012; NIOSH 2O10).
❖ EPA SW-846 Method 8015D uses gas
chromatography (GC) to determine the
concentration of 1,4-dioxane in environmental
samples. Samples may be introduced into the GC
column by a variety of techniques including the
injection of the concentrate from azeotropic
distillation (EPA SW-846 Method 5031). The
detection limits for 1,4-dioxane in aqueous
matrices by azeotropic microdistillation are 12 pg/L
(reagent water), 15 pg/L (groundwater) and 16
pg/L (leachate) (EPA 2003).
EPA SW-846 Method 8260B detects 1,4-dioxane
in a variety of solid waste matrices using GC and
mass spectrometry (MS). The detection limit
depends on the instrument and choice of sample
preparation method (ATSDR 2012; EPA 1996a).
A laboratory study is underway to develop a
passive flux meter (PFM) approach to enhance the
capture of 1,4-dioxane in the PFM sorbent to
improve accuracy. The selected PFM approach
will be field tested at 1,4-dioxane contaminated
sites. The anticipated projection completion date is
2014 (DoD SERDP 2013b).
❖ EPA Method 1624 uses isotopic dilution gas
chromatography — mass spectrometry (GC -MS) to
detect 1,4-dioxane in water, soil and municipal
sludges. The detection limit for this method is 10
pg/L (ATSDR 2012; EPA 2001 b).
❖ EPA SW-846 Method 8270 uses liquid -liquid
extraction and isotope dilution by capillary column
GC -MS. This method is often modified for the
detection of low levels of 1,4-dioxane in water
(EPA 2007, 2013a)
❖ GC -MS detection methods using solid phase
extraction followed by desorption with an organic
solvent have been developed to remove
1,4-dioxane from the aqueous phase. Detection
limits as low as 0.024 pg/L have been achieved by
passing the aqueous sample through an activated
carbon column, following by elution with acetone-
dichlormethane (ATSDR 2012; Kadokami and
others 1990).
❖ EPA Method 522 uses solid phase extraction and
GC/MS with selected ion monitoring for the
detection of 1,4-dioxane in drinking water with
detection limits ranging from 0.02 to 0.026 pg/L
(EPA 2008).
What technologies are being used to treat 1,4-dioxane?
❖ Pump -and -treat remediation can treat dissolved
1,4-dioxane in groundwater and control
groundwater plume migration, but requires ex situ
treatment tailored for the unique properties of
1,4-dioxane (such as, a low octanol-water partition
coefficient that makes 1,4-dioxane hydrophilic)
(EPA 2006; Kiker and others 2010).
❖ Commercially available advanced oxidation
processes using hydrogen peroxide with ultraviolet
light or ozone is used to treat 1,4-dioxane in
wastewater (Asano and others 2012; EPA 2006).
❖ A study is under way to investigate facilitated -
transport enabled in situ chemical oxidation to
treat 1,4-dioxane-contamined source zones and
groundwater plumes effectively. The technical
approach consists of the co -injection of strong
oxidants (such as ozone) with chemical agents
that facilitate the transport of the oxidant (DoD
SERDP 2013d).

What technologies are being used to treat 1,4-dioxane? (continued)
❖ Ex situ bioremediation using a fixed -film, moving -
bed biological treatment system is also used to
treat 1,4-dioxane in groundwater (EPA 2006).
❖ Phytoremediation is being explored as a means to
remove the compound from shallow groundwater.
Pilot -scale studies have demonstrated the ability
of hybrid poplars to take up and effectively
degrade or deactivate 1,4-dioxane (EPA 2001 a,
2013a; Ferro and others 2013).
❖ Microbial degradation in engineered bioreactors
has been documented under enhanced conditions
or where selected strains of bacteria capable of
degrading 1,4-dioxane are cultured, but the impact
of the presence of chlorinated solvent co -
contaminants on biodegradation of 1,4-dioxane
needs to be further investigated (EPA 2006,
2013a; Mahendra and others 2013).
❖ Results from a 2012 laboratory study found
1,4-dioxane-transforming activity to be relatively
common among monooxygenase-expressing
bacteria; however, both TCA and
1,1-dichloroethene inhibited 1,4-dioxane
degradation by bacterial isolates (DoD SERDP
2012).
❖ Several Department of Defense Strategic
Environmental Research and Development
Program (DoD SERDP) projects are under way to
investigate 1,4-dioxane biodegradation in the
presence of chlorinated solvents or metals.
Laboratory studies will (1) identify microbial
cultures as well as biogeochemistry, which
generate desirable enzymatic activity for
1,4-dioxane biodegradation; (2) assess
biodegradation by methane oxidizing bacteria in
coupled anaerobic -aerobic zones; (3) and
evaluate branched hydrocarbons as stimulants for
the in situ cometabolic biodegradation of
1,4-dioxane and its associated co -contaminants
(DoD SERDP 2013c, a and f).
❖ Photocatalysis has been shown to remove
1,4-dioxane in aqueous solutions. Laboratory
studies documented that the surface plasmon
resonance of gold nanoparticles on titanium
dioxide (Au — TiO2) promotes the photocatalytic
degradation of 1,4-dioxane (Min and others 2009;
Vescovi and others 2010).
❖ Other in -well combined treatment technologies
being assessed include air sparging; soil vapor
extraction (SVE); and dynamic subsurface
groundwater circulation (Odah and others 2005).
❖ SVE is known to remove some 1,4-dioxane, but
substantial residual contamination is usually left
behind because of 1,4-dioxane's high solubility,
which leads to preferential partitioning into pore
water rather than vapor. The DoD SERDP is
conducting a project to evaluate and demonstrate
the efficacy of enhanced or extreme SVE, which
uses a combination of increased air flow,
sweeping with drier air, increased temperature,
decreased infiltration and more focused vapor
extraction to enhance 1,4-dioxane remediation in
soils (DoD SERDP 2013a).
Where can I find more information about 1,4-dioxane?
❖ Asano, M., Kishimoto, N., Shimada, H., and Y.
Ono. 2012. "Degradation of 1,4-Dioxane Using
Ozone Oxidation with UV Irradiation (Ozone/UV)
Treatment." Journal of Environmental Science and
Engineering. Volume A (1). Pages 371 to 279.
❖ Agency for Toxic Substances and Disease
Registry (ATSDR). 2012. "Toxicological Profile for
1,4-Dioxane."
www.atsdr.cdc.gov/toxprofiles/tpl 87.pdf
❖ American Conference of Governmental Industrial
Hygienists (ACGIH). 2011. "2011 Threshold Limit
Values (TLVs) for Chemical Substances and
Physical Agents Biological Exposure Indices."
Cincinnati, Ohio.
❖ California Department of Public Health (CDPH).
2011. "1,4-Dioxane." Drinking Water Systems.
www.cdoh.ca.gov/certlic/drinkingwater/Pages/1,4-
dioxane.aspx
❖ Clean Air Act Amendments of 1990 (CAA). 1990.
"Hazardous Air Pollutants". 42 USC § 7412.
❖ Colorado Department of Public Health and the
Environment (CDPHE). 2012. "Notice of Public
Rulemaking Hearing before the Colorado Water
Quality Control Commission." Regulation No. 31
and No. 41.
www.sos.state.co.us/CCR/Upload/NoticeOfRulem
aking/ProposedRuleAttach20l 2-00387. PDF
❖ Ferro, A.M., Kennedy, J., and J.C. LaRue. 2013.
"Phytoremediation of 1,4-Dioxane-Containing
Recovered Groundwater." International Journal of
Phytoremediation. Volume 15. Pages 911 to 923.
❖ Giavini, E., Vismara, C., and M.L Broccia. 1985.
"Teratogenesis Study of Dioxane in Rats."
Toxicology Letters. Volume 26 (1). Pages. 85 to
88.

Where can I find more information about 1,4-dioxane? (continued)
❖ Graedel, T.E. 1986. Atmospheric Chemical
Compounds. New York, NY: Academic Press.
❖ Hazardous Substances Data Bank (HSDB). 2011.
1,4-Dioxane." http://toxnet.nim.nih.gov/cqi-bin/
sis/htmlgen?HSDB
❖ HazDat. 2007. "1,4-Dioxane." HazDat Database:
ATSDR's Hazardous Substance Release and
Health Effects Database. Atlanta, GA: Agency for
Toxic Substances and Disease Registry.
❖ Howard, P.H. 1990. Handbook of Environmental
Fate and Exposure Data for Organic Chemicals.
Lewis Publishers, Inc., Chelsea, MI. Pages 216 to
221.
❖ Kadokami, K, Koga, M. and A. Otsuki. 1990. "Gas
Chromatography/Mass Spectrometric
Determination of Traces of Hydrophilic and
Volatile Organic Compounds in Water after
Preconcentration with Activated Carbon."
Analytical Sciences. Volume 6(6). Pages 843 to
849.
❖ Kiker, J.H., Connolly, J.B., Murray, W.A., Pearson,
S.C.; Reed, S.E., and R.J. Robert. 2010. "Ex -Situ
Wellhead Treatment of 1,4-Dioxane Using
Fenton's Reagent." Proceedings of the Annual
International Conference on Soils, Sediments,
Water and Energy. Volume 15, Article 18.
❖ Mahendra, S., Grostern, A. and L. Alvarez -Cohen.
2013. "The Impact of Chlorinated Solvent Co -
Contaminants on the Biodegradation Kinetics of
1,4-Dioxane." Chemosphere. Volume 91 (1).
Pages 88 to 92.
❖ Massachusetts Department of Environmental
Protection (Mass DEP). 2012. "Standards and
Guidelines for Contaminants in Massachusetts
Drinking Waters."
www.mass.gov/dep/water/dwstand.pdf
❖ Min, B.K., Heo, J.E., Youn, N.K., Joo, O.S., Lee,
H., Kim, J.H., and H.S. Kim. 2009. "Tuning of the
Photocatalytic 1,4-Dioxane Degradation with
Surface Plasmon Resonance of Gold
Nanoparticles on Titania." Catalysis
Communications. Volume 10 (5). Pages 712 to
715.
❖ Mohr, T.K.G. 2001. "1,4-Dioxane and Other
Solvent Stabilizers White Paper." Santa Clara
Valley Water District of California. San Jose,
California.
❖ National Institute for Occupational Safety and
Health (NIOSH). 2010. "Dioxane." NIOSH Pocket
Guide to Chemical Hazards.
www.cdc.gov/niosh/npq/npqd0237.htmi
❖ New Hampshire Department of Environmental
Services (NH DES). 2011 "Change in Reporting
Limit for 1,4-Dioxane."
http://des.nh.gov/organization/divisions/waste/hwr
b/sss/hwrp/documents/report-limits 14dioxane. pdf
❖ Occupational Safety and Health Administration
(OSHA). 2013. "Dioxane." Chemical Sampling
Information. www.osha.gov/dts/chemicalsampling/
data/CH 237200.html
❖ Odah, M.M., Powell, R., and D.J. Riddle. 2005.
"ART In -Well Technology Proves Effective in
Treating 1,4-Dioxane Contamination."
Remediation Journal. Volume 15 (3), Pages 51 to
64.
❖ U.S. Department of Defense (DoD). Strategic
Environmental Research and Development
Program (SERDP). 2012. "Oxygen ase-Catalyzed
Biodegradation of Emerging Water Contaminants:
1,4-Dioxane and N-Nitrosodimethylamine." ER-
1417. www.serdp.org/Program-Areas/
Environmental-Restoration/Contam inated-
Groundwater/Emerging-Issues/ER-1417/ER-1417
❖ DoD SERDP. 2013a. "1,4-Dioxane Remediation
by Extreme Soil Vapor Extraction (XSVE)." ER-
201326. www.serdp.org/Program-Areas/
Environmental-Restoration/Contaminated-Ground
water/Emerging-Issues/ER-201326/ER-201326
❖ DoD SERDP. 2013b. "Development of a Passive
Flux Meter Approach to Quantifying 1,4-Dioxane
Mass Flux." ER-2304. www.serdp.org/Program-
Areas/Environ mental-Restoration/Contam inated-
Groundwater/Emerging-Issues/ER-2304/ER-2304/
❖ DoD SERDP. 2013c. "Evaluation of Branched
Hydrocarbons as Stimulants for In Situ
Cometabolic Biodegradation of 1,4-Dioxane and
Its Associated Co -Contaminants." ER-2303.
www.serdp.org/Program-Areas/Environmental-
Restoration/Contam i nated-Groundwater/
Emerging-Issues/ER-2303/ER-2303
❖ DoD SERDP. 2013d. "Facilitated Transport
Enabled In Situ Chemical Oxidation of 1,4-
Dioxane-Contaminated Groundwater." ER-2302.
www.serdp.org/Program-Areas/Environmental-
Restoration/Contam i nated-Groundwater/
Emerging-Issues/ER-2302/ER-2302/(language)/
eng-US
❖ DoD SERDP. 2013e. "In Situ Biodegradation of
1,4-Dioxane: Effects of Metals and Chlorinated
Solvent Co -Contaminants." ER-2300.
www.serdp.org/Program-Areas/Environmental-
Restoration/Contam i nated-Groundwater/
Emerging-Issues/ER-2300/ER-2300

Where can I find more information about 1,4-dioxane? (continued)
❖ DoD SERDP. 2013f. "In Situ Bioremediation of
1,4-Dioxane by Methane Oxidizing Bacteria in
Coupled Anaerobic -Aerobic Zones." ER-2306.
www.serdp.org/Program-Areas/Environmental-
Restoration/Contaminated-Groundwater/
Emerging- Issues/ER-2306/ER-2306
❖ U.S. Department of Health and Human Services
(DHHS). 2011. "Report on Carcinogens, Twelfth
Edition." Public Health Service, National
Toxicology Program. 12t" Edition.
http://ntp.niehs.nih.gov/ntp/roc/twelfth/rocl2.pdf
❖ U.S. Environmental Protection Agency (EPA).
1996a. "Method 8260B: Volatile Organic
Compounds by Gas Chromatography/Mass
Spectrometry (GC/MS)." www.epa.gov/osw/
hazard/testmethods/sw846/pdfs/8260b.pdf
❖ EPA. 1996b. "Solvents Study." EPA 530-R-96-
017.
❖ EPA. 2001a. "Brownfields Technology Primer:
Selecting and Using Phytoremediation for Site
Cleanup." EPA 542-R-01-006.
www.brownfieldstsc.orq/pdfs/phytorem primer.pdf
❖ EPA. 2001 b. "Method 1624." Code of Federal
Regulations. Code of Federal Regulations. 40
CFR Part 136. Pages 274 to 287.
❖ EPA. 2003. "Method 8015D: Nonhalogenated
Organics Using GC/FID." SW-846. www.epa.gov/
osw/hazard/testmethods/pdfs/8015d r4.pdf
❖ EPA. 2006. "Treatment Technologies for
1,4-Dioxane: Fundamentals and Field
Applications." EPA 542-R-06-009.
www.epa.gov/tio/download/remed/542r06009.pdf
❖ EPA. 2007. "Method 8270D: Semivolatile Organic
Compounds by Gas Chromatography/Mass
Spectrometry (GC/MS)."
❖ EPA. 2008. "Method 522: Determination of
1,4-Dioxane in Drinking Water By Solid Phase
Extraction (SPE) and Gas Chromatography/Mass
Spectrometry (GC/MS) with Selected Ion
Monitoring (SIM)." EPA/600/R-08/101.
❖ EPA. 2009. "Drinking Water Contaminant
Candidate List 3 - Final." Federal Register Notice.
www.federalregister.gov/articles/2009/10/08/E9-
24287/drinking-water-contaminant-candidate-list-
3-final
❖ EPA. 2011. "Reportable Quantities of Hazardous
Substances Designated Pursuant to Section 311
of the Clean Water Act. Code of Federal
Regulations." 40 CFR 302.4.
www.gpo.gov/fdsVs/pkq/CFR-2011-title40-
vol28/pdf/CFR-2011-title40-vo128-sec302-4. pdf
❖ EPA. 2012. "2012 Edition of Drinking Water
Standards and Health Advisories."
water. epa.gov/action/advisories/d ri nki ng/upload/d
wstandards2012. pdf
❖ EPA. 2013a. "1,4-Dioxane." www.clu-in.org/conta
minantfocus/default.focus/sec/1,4-Dioxane/
cat/Overview/
❖ EPA. 2013b. "1,4-Dioxane (1,4-Diethyleneoxide)."
Technology Transfer Network Air Toxics Website.
www.epa.gov/ttnatwOl/hlthef/dioxane.html
❖ EPA. 2013c. Regional Screening Level (RSL)
Summary Table.
www.epa.gov/reg3hwmd/risk/human/rb-
concentration table/Generic Tables/index.htm
❖ EPA. Integrated Risk Information System (IRIS).
2013. "1,4-Dioxane (CASRN 123-91-1)."
www.epa.gov/iris/subst/0326.htm
❖ U.S. Food and Drug Administration (FDA). 2006.
"Food Additives Permitted for Direct Addition to
Food for Human Consumption; Glycerides and
Polyglycides." Code of Federal Regulations. 21
CFR 172.736.
❖ Vescovi, T., Coleman, H., and R. Amal. 2010.
"The Effect of pH on UV -Based Advanced
Oxidation Technologies - 1,4-Dioxane
Degradation." Journal of Hazardous Materials.
Volume 182. Pages 75 to 79.
Additional information on 1,4-dioxane can be found at
www.cluin.org/contaminantfocus/default.focus/sec/1,4-Dioxane/cat/Overview
Contact Information
If you have any questions or comments on this fact sheet, please contact: Mary Cooke, FFRRO, by phone at
[phone] or by email at cooke.maryt(o)epa.gov.