7901_RockinghamMSWLF_ 1_4_DioxaneSubSetRequest_FID1889041_20240723

July 16, 2024

Mr. Ervin Lane
Compliance Hydrogeologist
North Carolina Department of Environmental Quality
Division of Waste Management – Solid Waste Section
1646 Mail Service Center
Raleigh, North Carolina 27699-1646
Via email: [e-mail]

Dear Mr. Lane:

The North Carolina Department of Environmental Quality (NCDEQ) Memo dated May 29, 2018, entitled
“1,4-Dioxane Analysis, Solid Waste Section Limits, and Laboratory Analytical Methods” requires all
groundwater and surface water samples collected at landfills be analyzed for 1,4-dioxane. In
accordance with this requirement, Rockingham County has had groundwater and surface water
samples analyzed for 1,4-dioxane during each semiannual monitoring event. It is our understanding
through conversations with NCDEQ staff that an owner/operator of a solid waste landfill may request suspension of 1,4-dioxane analysis for certain wells/surface water points if such locations have not
detected 1,4-dioxane.
On behalf of Rockingham County and Wall Recycling, LLC, Labella Associates, P.C. (LaBella) requests
that beginning with the Fall 2024 monitoring event, the following monitoring wells and surface water
locations be removed from the requirement for 1,4-dioxane analysis:

There have been no detections of 1,4-dioxane in any of the above monitoring wells and surface water
locations since the analytical requirement was put into effect in 2018. (attached) provide a summary of 1,4-dioxane analytical results since 2018.

All other compliance wells, surface water monitoring points, and leachate will continue to be monitored
for 1,4-dioxane.

LaBella appreciates your consideration of this request. Please feel free to contact me at (336) 790-
0124 if you have any questions.

Respectfully submitted,

Scott Gregory, P.G.
Senior Technical Geologist

cc: Ronnie Tate – Rockingham County
Chris Gustin – Wall Recycling
Dan Jarboe – Wall Recycling
Charlie Jarboe – Wall Recycling
Kandice Estes – Wall Recycling

Attachments – Table 1 – Historical 1,4-Dioxane Concentrations (Areas I-V Permit 79-01)
Table 2 - Historical 1,4-Dioxane Concentrations (Subtitle D Permit 79-04)
Table 3 – Historical 1,4-Dioxane Concentrations in Surface Water
Table 1
Historical 1,4-Dioxane Concentrations
Rockingham County Landfill
Areas I-V
Permit No. 79-01
Analyte Collection Date Method DL RL MW-4A MW-6 MW-7 MW-12S MW-12D MW-13S MW-13D MW-1A MW-5 MW-9 MW-11 NES-1
1,4-Dioxane 4-Oct-18 8260C 1.2 2.0 ND 10.0 7.0 NS NS ND ND ND ND 4.8 ND ND
4-Apr-19 8260D 1.2 2.0 ND 4.8 ND ND ND ND ND ND ND 6.1 ND ND
NC 2L = 3 µg/L 18-Sep-19 8260D 1.2 2.0 ND 28.0 37.0 NS NS ND ND ND ND 9.0 ND ND
9-Apr-20 8260D 0.80 2.0 ND 10.0 2.6 NS NS ND ND ND ND 7.8 ND ND
7-Oct-20 8260D 0.80 2.0 ND 26.0 38.0 NS NS ND ND ND ND 8.8 ND ND
8-Apr-21 8260D 0.80 2.0 ND 6.7 ND ND ND ND ND ND ND 10 ND ND
7-Oct-21 EPA 8260 SIM 0.80 2.0 ND ND 45.0 ND ND ND ND ND ND 9.8 ND ND
27-Apr-22 EPA 8260 SIM 0.80 2.0 ND 14.0 2.5 NS NS ND ND ND 3.3 8.3 ND ND
14-Nov-22 EPA 8260 SIM 0.14 2.0 ND ND ND NS NS ND ND ND ND NS ND ND
22-Mar-23 EPA 8260D SIM 2.0 2.0 ND 13.6 20.2 ND ND ND ND ND ND NS ND ND
3-Oct-23 8260D SIM 14D 0.32 0.50 ND 43.9 54.1 NS NS ND ND ND ND 11.3 ND ND
26-Mar-24 EPA 8260D SIM 14D 0.32 0.50 ND 7.04 7.02 NS NS ND ND ND ND 11.5 ND ND
Concentrations in micrograms per liter (ug/L)
DL = Detection Limit
RL = Reporting Limit
NS = Not Sampled
ND = Not detected above DL or RL as applicable
Rockingham County Landfill
Permit No. 79-01 LaBella Associates
Table 2
Historical 1,4-Dioxane Concentrations
Rockingham County Landfill
Subtitle D
Permit No. 79-04
Analyte Collection Date Method DL RL MW-2 MW-3 MW-4 MW-6
17-Sep-19 8260D 1.2 2.0 ND ND 1.30 J ND ND ND ND
9-Apr-20 8260D 0.80 2.0 ND ND 1.40 J ND ND ND ND
1,4-Dioxane 7-Oct-20 8260D 0.80 2.0 ND ND 1.40 J ND ND ND ND
NC2L = 3 µg/L 8-Apr-21 8260D 0.80 2.0 ND ND 1.70 J ND ND ND ND
7-Oct-21 EPA 8260 SIM 0.80 2.0 ND ND 1.60 J ND ND ND 32
27-Apr-22 EPA 8260 SIM 0.80 2.0 ND ND 1.80 J ND ND ND ND
14-Nov-22 EPA 8260 SIM 0.14 2.0 ND ND 1.95 J ND ND ND ND
20-Mar-23 EPA 8260D SIM 2.0 2.0 ND ND 2.14 ND ND ND ND
3-Oct-23 EPA 8260D SIM 14D 0.32 0.50 ND ND 1.79 ND ND ND ND
26-Mar-24 EPA 8260D SIM 14D 0.32 0.50 ND ND 1.63 ND ND ND ND
Concentrations in micrograms per liter (ug/L)
DL = Detection Limit
RL = Reporting Limit
NS = Not Sampled
ND = Not detected above DL or RL as applicable
NI = Well Not Installed
J = Estimated value
MW-5DMW-1S MW-1D
Rockingham County Landfill
Permit No. 79-04 Page 1 of 3 LaBella Associates
Table 2
Historical 1,4-Dioxane Concentrations
Rockingham County Landfill
Subtitle D
Permit No. 79-04
Analyte Collection Date Method DL RL
17-Sep-19 8260D 1.2 2.0
9-Apr-20 8260D 0.80 2.0
1,4-Dioxane 7-Oct-20 8260D 0.80 2.0
NC2L = 3 µg/L 8-Apr-21 8260D 0.80 2.0
7-Oct-21 EPA 8260 SIM 0.80 2.0
27-Apr-22 EPA 8260 SIM 0.80 2.0
14-Nov-22 EPA 8260 SIM 0.14 2.0
20-Mar-23 EPA 8260D SIM 2.0 2.0
3-Oct-23 EPA 8260D SIM 14D 0.32 0.50
26-Mar-24 EPA 8260D SIM 14D 0.32 0.50
Concentrations in micrograms per liter (ug/L)
DL = Detection Limit
RL = Reporting Limit
NS = Not Sampled
ND = Not detected above DL or RL as applicable
NI = Well Not Installed
J = Estimated value
MW-7D MW-8 MW-9 MW-10D MW-12 MW-15 MW-16D
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND

MW-11 MW-13D MW-14 MW-16S
Rockingham County Landfill
Permit No. 79-04 Page 2 of 3 LaBella Associates
Table 2
Historical 1,4-Dioxane Concentrations
Rockingham County Landfill
Subtitle D
Permit No. 79-04
Analyte Collection Date Method DL RL
17-Sep-19 8260D 1.2 2.0
9-Apr-20 8260D 0.80 2.0
1,4-Dioxane 7-Oct-20 8260D 0.80 2.0
NC2L = 3 µg/L 8-Apr-21 8260D 0.80 2.0
7-Oct-21 EPA 8260 SIM 0.80 2.0
27-Apr-22 EPA 8260 SIM 0.80 2.0
14-Nov-22 EPA 8260 SIM 0.14 2.0
20-Mar-23 EPA 8260D SIM 2.0 2.0
3-Oct-23 EPA 8260D SIM 14D 0.32 0.50
26-Mar-24 EPA 8260D SIM 14D 0.32 0.50
Concentrations in micrograms per liter (ug/L)
DL = Detection Limit
RL = Reporting Limit
NS = Not Sampled
ND = Not detected above DL or RL as applicable
NI = Well Not Installed
J = Estimated value
MW-17S MW-17D MW-19R MW-21R MW-23R MW-24 MW-25 MW-26 MW-28
ND ND ND ND ND ND NI NI NI NI NI
ND ND ND ND ND ND NI NI NI NI NI
ND ND NS ND ND ND ND ND ND ND NS
ND ND ND ND ND ND ND ND ND ND ND
ND ND NS ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND NS ND ND ND ND NS NS ND ND
ND ND ND ND ND ND ND ND ND ND ND
ND ND NS ND ND ND ND ND ND ND ND
ND ND ND ND ND ND ND ND ND ND ND
MW-27MW-19
Rockingham County Landfill
Permit No. 79-04 Page 3 of 3 LaBella Associates
Table 3
Historical 1,4-Dioxane Concentrations in Surface Water
Rockingham County Landfill
Permit No. 79-04
Analyte
Sample
Collection
Date
Method DL RL SMP-1 SMP-2 SMP-3 SMP-4
1,4-Dioxane 07-Oct-20 8260D 0.80 2.0 ND 0.86 J ND ND
08-Apr-21 8260D 0.80 2.0 ND ND ND ND
ISTV = 0.35 µg/L 07-Oct-21 EPA 8260 SIM 0.80 2.0 ND 1.4 J ND ND
27-Apr-22 EPA 8260 SIM 0.80 2.0 ND 1.1 J ND ND
14-Nov-22 EPA 8260 SIM 0.139 2.0 ND ND ND ND
20-Mar-23 EPA 8260D SIM 2.0 2.0 ND ND ND ND
03-Oct-23 8260D SIM 14D 0.32 0.50 ND 0.713 ND ND
26-Mar-24 EPA 8260D SIM 14D 0.32 0.50 ND 0.356 J ND ND
Concentrations in micrograms per liter (ug/L)
DL = Detection Limit
RL = Reporting Limit
J = Estimated value
ND = Not detected above DL or RL as applicable
ISTV = North Carolina In-Stream Target Values for Surface Waters
Rockingham County Landfill
Permit No. 79-04 LaBella Associates