6013_Mecklenburg_NorthMeck_GreenwayWaste_CDLF_LFGTrenchReport_FID1906926_20241105

R Griffin Brothers Co.
Greenau Waste Solutions
Sent Via E-mail to
i aclynne.drummond(&deg.nc.2ov
November 5, 2024
NC Department of Environmental Quality
Solid Waste Section
217 W Jones Street
Raleigh, NC 27603
Attn: Ms. Jaclynne Drummond,
Re: Soil Gas Ventilation Trench Installation Report
Active Infill Disposal Area
Greenway Waste Solutions at North Meck, LLC
Huntersville, North Carolina
Solid Waste Facility Permit Number 60-13
Dear Ms. Drummond:
Greenway Waste Solutions at North Meck, LLC (GWSNM) is pleased to present this letter report
documenting recent soil gas ventilation trench installation at the Greenway Waste Solutions at North
Meck C&D Landfill located at 15300 Holbrooks Rd in Huntersville, NC 28078. In accordance with
the Landfill Gas Migration Corrective Action Plan (FID 1891408), dated March 29, 2023, and
approved on August 5, 2024 (FID 1891465), the ventilation trench was installed to address elevated
methane concentrations in perimeter methane monitoring well MMW-3, as well as landfill gas
(LFG) assessment wells GP-1 and GP-2. A map depicting the location of the new soil gas
ventilation trench is provided as Figure 1.
Soil Gas Ventilation Trench Installation
Trench installation activities were conducted by GWSNM staff from October 1 through October 8,
2024. The trench was excavated to a depth of approximately 20 feet below ground surface along a
total length of 135 feet. The trench was filled to a depth of six feet below ground surface with
NCDOT No. 4A coarse aggregate, upon which 130 linear feet of 6-inch HDPE DR -I I perforated

Ms. Jaclynne Drummond
November 5, 2024
Page 2
collection pipe was installed along the trench alignment. The perforated pipe was covered with
approximately 12 inches of NCDOT No. 4A coarse aggregate, upon which a non -woven geotextile
fabric was installed in accordance with the approved trench design (Figure 2). The trench was then
backfilled with site soils which were compacted in approximately 18-inch lifts, followed by dozer
compaction upon backfilling to the surrounding grade. Vertical ventilation pipes were completed
with passive "Whirlybird" rotary turbines. GWSNM will continue monthly monitoring of MMW-3,
GP-1, and GP-2 to evaluate the efficacy of this corrective action.
Should you have any questions or require any additional information, please feel free to contact me
at [phone] or [e-mail].
Sincerely,
Brandt Kayser, P.G.
Environmental Compliance Officer
Attachments:
Figure 1 — Passive Gas Collection Trench Location Map
Figure 2 — Passive Gas Collection Trench - Details
B Griffin Brothers CO -
Green
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LEGEND
--- --- PROPERTY LINE
b MMW-1 INFILL AREA
METHANE MONITORING WELL
LANDFILL POINT OF
® MW-4A COMPLIANCE GROUNDWATER
MONITORING WELL
@GP-1 GAS PROBE
REFERENCE
TRENCH LOCATION
(-135 LF)
SCALE IN FEET
mommi
0 100 200
'' GP-2
1. AERIAL IMAGERY BY CIVIL & ENVIRONMENTAL CONSULTANTS,
DATED JUNE 4, 2024.

200' MAXIMUM VENT PIPE SPACING
V� PASSIVE GAS COLLECTION TRENCH DETAIL
N.T.S.
♦IA ALL HOLES
6" (TYP.) 1/2" 0 \
900 \
Al TYP.
,+JA 6"0 HDPE
DSECTION A -A
R-11 PIPE
PERFORATION PATTERN
2 HDPE PIPE PERFORATIONS
2 N.T.S.
6" STAINLESS TURBINE
VENTILATOR (TYP.)
u
DR-11
F
_RFORATED
PE (TYP.)
NON -WOVEN FILTER
FABRIC TO BE PLACED
BETWEEN AGGREGATE
AND SOIL BACKFILL
6" HDPE DR-11 NON -
PERFORATED 90 DEGREE
ELBOWS (TYP.)
6" HDPE DR-11
PERFORATED EXTRACTION
PIPE (SEE DETAIL 2)
NCDOT NO. 4A
COARSE AGGREGATE
NONCALCEROUS STONE
ONLY (NO FINES)
TERMINATE P
OR ROCK, 0« vrviv r«rwnnvv
DEPTH LIMIT OF 20 FEET
A SECTION
2 N.T.S.
SOIL BACKFILL
NON -WOVEN 6 OZ/SY
GEOTEXTILE TO BE
PLACED BETWEEN
AGGREGATE AND SOIL
BACKFILL
6" HDPE PERFORATED
PIPE (SEE DETAIL 2)
VCDOT NO. 4A
-OARSE AGGREGATE
VONCALCEROUS STONE
DNLY (NO FINES)