7904_RockinghamMSWLF_ February2025LFGMR_FID1996722_20250331

February 10, 2025
Mr. Ervin Lane
Compliance Hydrogeologist
North Carolina Department of Environmental Quality
Solid Waste Section
1646 Mail Service Center
Raleigh, NC 27699-1646

Dear Mr. Lane:
On behalf of Rockingham County and Wall Recycling, LLC (Wall), LaBella Associates (LaBella) is
submitting the attached methane monitoring results for the Rockingham County Solid Waste
Management Facility, Permit Nos. 79-01 and 79-04.
The 2025 First Quarter Landfill Gas Monitoring event was performed on February 6, 2025. The
monitoring program for the Rockingham County Solid Waste Management Facility includes a total of
20 permanent gas monitoring probes and seven structures. The approximate locations of the probes
and the structures are depicted on .
The results of the 2025 First Quarter Monitoring Event are summarized in the attached
. According to the monitoring readings, methane concentrations were detected
above the instrument detection level of 0.0 percent volume in boundary probes 7901-M-4 (1.1%),
7901-M-5 (18.5%), and 7901-M-12 (49.1%).
Methane was detected at concentrations above the regulatory limit of 100% of the Lower Explosive
Limit (LEL), or 5 percent volume in boundary probes 7901-M-5 and 7901-M-12. The methane detections and the exceedances of the LEL are summarized in the attached and ,
respectively.
The methane concentration in boundary probe 7901-M-12 has increased compared to the previous
quarterly event ().Due to persistent regulatory exceedances in this boundary probe and probe
7901-M-5, LaBella, on behalf of Rockingham County, submitted a Landfill Gas Remediation Activity
Update and Remediation Plan (“Plan”) dated March 11, 2024, to address the methane exceedances.
The Plan was approved by the North Carolina Department of Environmental Quality Solid Waste Section
(NCDEQ-SWS) on March 20, 2024.
During the week of April 22nd, 2024, three soil vents were installed between boundary probe 7901-M-
5 and closed Area III and connected to the landfill gas extraction system through gas extraction well
GV3-1. These soil vents have been monitored weekly since their installation, and this remediation
strategy initially reduced methane concentrations in 7901-M-5. Methane concentrations in 7901-M-5
have increased recently due to condensate accumulation that will be addressed once vegetation
management has been completed by the facility. The Plan proposed the installation of vents between
7901-M-12 and closed Area III; however, LaBella plans to continue monitoring the trend in 7901-M-
12 to evaluate whether additional vents will be needed.

2
The next quarterly monitoring event is scheduled for May 2025. Please feel free to contact me at (336)
790-0124 with any questions regarding this submittal.
Respectfully submitted,
Scott Gregory, PG
Senior Technical Geologist/Environmental Manager

Attachments: North Carolina Environmental Monitoring Reporting Form
Tables 1, 2, and 3 Landfill Gas Monitoring Data Form
Drawing No. 1

cc: Ronnie Tate, Rockingham County
Chris Gustin, Wall Recycling
Kandice Estes, Wall Recycling

Date Location CH4 (% LEL)CH4 (% Volume)
2/6/2025 7901-M4 20 1.1
2/6/2025 7901-M5 370 18.5
2/6/2025 7901-M-12 982 49.1
CH4 = Methane
LEL = Lower Explosive Limit for Methane
LEL = 5% by volume at standard temperature and pressure
BOLD = Methane concentration above LEL
TABLE 1: Methane Detections at Boundary Probes
Rockingham County Landfill
Permits # 79-01, 79-04 LaBella Associates
Date Location CH4 (% LEL)CH4 (% Volume)
2/6/2025 7901-M-5 370 18.5
2/6/2025 7901-M-12 982 49.1
CH4 = Methane
LEL = Lower Explosive Limit for Methane
LEL = 5% by volume at standard temperature and pressure
TABLE 2: Exceedances of the LEL
Rockingham County Landfill
Permits # 79-01, 79-04 LaBella Associates
TABLE 3: Historical Data
Date Location CH4 (% LEL)CH4 (% Volume)
3/18/2019 7901-M-5 0.0 0.0
7/1/2019 7901-M-5 0.0 0.0
9/30/2019 7901-M-5 1,204 60.2
12/10/2019 7901-M-5 1,152 57.6
1/27/2020 7901-M-5 1,178 58.9
4/6/2020 7901-M-5 0.0 0.0
6/23/2020 7901-M-5 418 20.9
12/29/2020 7901-M-5 0.0 0.0
1/26/2021 7901-M-5 364 18.2
4/6/2021 7901-M-5 0.0 0.0
7/13/2021 7901-M-5 800 40.0
1/19/2022 7901-M-5 480 24.0
4/28/2022 7901-M-5 1,004 50.2
7/20/2022 7901-M-5 NM NM
1/27/2023 7901-M-5 954 47.7
2/16/2023 7901-M-5 692 34.6
3/1/2023 7901-M-5 936 46.8
3/7/2023 7901-M-5 724 36.2
3/8/2023 7901-M-5 706 35.3
3/20/2023 7901-M-5 900 45.0
3/29/2032 7901-M-5 586 29.3
6/27/2023 7901-M-5 626 31.3
9/5/2023 7901-M-5 840 42.0
11/30/2023 7901-M-5 618 30.9
3/28/2024 7901-M-5 774 38.7
6/20/2024 7901-M-5 0.0 0.0
9/6/2024 7901-M-5 50.0 2.5
2/6/2025 7901-M-5 370 18.5
3/18/2019 7901-M-12 676
4/8/2019 7901-M-12 1,194
5/18/2019 7901-M-12 614
6/7/2019 7901-M-12 1,114
7/1/2019 7901-M-12 1,028
8/13/2019 7901-M-12 1,152
9/30/2019 7901-M-12 1,156
11/12/2019 7901-M-12 984
12/10/2019 7901-M-12 1,122
1/27/2020 7901-M-12 1,160
4/6/2020 7901-M-12 1,140
6/22/2020 7901-M-12 1,162
12/29/2020 7901-M-12 1,190
1/26/2021 7901-M-12 468
4/6/2021 7901-M-12 1,146
7/13/2021 7901-M-12 628
4/28/2022 7901-M-12 788
7/20/2022 7901-M-12 NM NM
7901-M-12 Historical Data
7901-M-5 Historical Data
Rockingham County Landfill
Permits # 79-01, 79-04 1 of 2 LaBella Associates
TABLE 3: Historical Data
Date Location CH4 (% LEL)CH4 (% Volume)
7901-M-5 Historical Data
1/27/2023 7901-M-12 16.0 0.80
2/16/2023 7901-M-12 1,152 57.6
3/1/2023 7901-M-12 1,152 57.6
3/7/2023 7901-M-12 1,152 57.6
3/8/2023 7901-M-12 1,152 57.6
3/20/2023 7901-M-12 646 32.3
3/29/2023 7901-M-12 36.0 1.8
6/27/2023 7901-M-12 954 47.7
9/5/2023 7901-M-12 1,010 50.5
11/30/2023 7901-M-12 802 40.1
3/28/2024 7901-M-12 996 49.8
6/20/2024 7901-M-12 468 23.4
9/6/2024 7901-M-12 1,002 50.1
11/25/2024 7901-M-12 906 45.3
2/6/2025 7901-M-12 982 49.1
CH4 = Methane
LEL = Lower Explosive Limit for Methane
LEL = 5% by volume at standard temperature and pressure
NM = Not Measured
BOLD = Methane concentration above LEL
7901-M-12 Historical Data (Continued)
Rockingham County Landfill
Permits # 79-01, 79-04 2 of 2 LaBella Associates
ACTIVE
PHASE 3
(9.5 AC)
EXISTING
PHASE 2
(9.0 AC)
EXISTING
PHASE 1
(19.0 AC)
MAINTENANCE BUILDING /
OFFICE
EXISTING
SED BASIN NO.1
EXISTING
LEACHATE LAGOON
PROPERTY LINE
EXISTING
SED BASIN NO.2
LMP-1 GV-36AGV-37 GV-36GV-37A
GV-31
GV-31A
GV-2
GV-1
GV-10
CONVENIENCE CENTERSCALE HOUSE
WHITE GOODS
(APPROVED BY DEQ)
OLD SHOP
M-4M-5
M-2
M-1
M-10
M-9
M-8
M-6
GV5-4
GV3-8 GV3-9
GV3-3
GV3-1
GV3-7
GV3-6
GV5-2
GV5-1
M-7
GV-1
GV-2
GV-3
M-9A
M-7A
M-8A
M-10A
GV-4
GV-5
GV-6
GV-8
GV-7
CLOSED
AREA III
(PERMIT 7901)
CLOSED
AREA IV
(PERMIT 7901)
CLOSED
AREAS I - II
(PERMIT 7901)
SMP-2
CONCRETE AND
BRICK STORAGE
APPROXIMATE
LIMITS OF
TEMPORARY
MULCH
STORAGE TIRES
APPROXIMATE
LIMITS OF
ROLL OFF
CONTAINER
STORAGE AREA
APPROXIMATE
LIMITS OF
ELECTRONICS
RECYCLING
STORAGE AREA
APPROXIMATE LIMITS
OF WASTE (TYP)
M-3
GV5-3
PHASE 1-3
PERMIT 7904
GV3-4
GV3-2
EXISTING GAS SYSTEM (TYP)
GW-43
GW-38
GW-40
GW-41
GW-44
GW-45
GW-46
GW-47
GW-49
GW-48
GW-50
GW-51
GW-52
GW-53
GW-63
PHASE 4
(11.0 AC)
EXISTING
SEDIMENT
BASIN NO. 5
EXISTING
SED BASIN NO.3
EXISTING
SED BASIN NO.4
PHASE 5
(10.7 AC.)
PHASE 6
(7.7 AC)
PHASE 7
(13.7 AC)
LEGEND
EXISTING GAS PROBE LOCATION AND IDENTIFICATION
PROPOSED GAS PROBE LOCATION AND IDENTIFICATION
EXISTING GAS VENT LOCATION AND IDENTIFICATIONGV-#
M-#
SUB D M-1
SUB D M-2
SUB D M-7
SUB D M-5
SUB D M-4
SUB D M-3
SUB D M-2A
SUB D M-8
SUB D M-9
STORM
SHELTER
HAY BARN
M-11
M-12
GV3-16
GV3-15
GV3-17
GV3-14
GV3-13
GV3-12
GV2-9
GV2-8 GV2-7
GV2-6
GV4-4GV4-1
GV4-2 GV4-3
GV3-5
GW-55
GW-57
GW-60
GW-58
GW-56GW-54
GW-60
GW-62
GW-61
GW-#EXISTING GAS WELL LOCATION AND IDENTIFICATION
66
0
68
0
720
740
70
0
720
800
780
750
690
690
670
650
630
59
0
61
0
63
0
640
620
600
760
74
0
72
0
750
730
710
690
650
650
670
690
710
65
067
0
690
690680
660
68
0
690
71
0
66
0
640
620
72
0
70
068
0
680
66
0
670
650
630
620
650680
670
65
0
590
610
630
660630610
740
760
750
750
740
74
0
68
0
650
630
SUB D-M10
SUBD-M11
SUBD-M12
SUBD-M13
M-#
GV3-10
GV3-11
APPROXIMATE LIMITS OF WOOD
WASTE STORAGE AREA
(APPROVED BY DEQ IN A LETTER
DATED MARCH 4, 1996)
CLOSED
AREA V
(PERMIT 7901)
0
(FEET)
GRAPHIC SCALE
600300150
Revisions
NO:DATE:DESCRIPTION:
DRAWING NAME:
6/
3
/
2
0
1
0

8
:
4
7
:
5
6

A
M
DRAWING NUMBER:
DATE:
ISSUED FOR:
DRAWN BY:
REVIEWED BY:
PROJECT NUMBER:
© 2023 LaBella Associates
12-D OAK BRANCH DRIVE
GREENSBORO, NC.
[phone]
labellapc.com
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LANDFILL GAS
MONITORING PLAN
ROCKINGHAM COUNTY
WENTWORTH, NORTH CAROLINA
ROCKINGHAM COUNTY LANDFILL
MADISON, NORTH CAROLINA
2233671
PERMITTING
12/13/23