9204_Wake_Sorrell_MSWLF_June23CoverMaint_FID1809531_20230627

June 27, 2023
Solid Waste Section
NCDEQ Division of Waste Management
217 West Jones Street
Raleigh, North Carolina 27603
Attn: Ms. Jackie Drummond via email: [e-mail]
Reference: Landfill Cover Inspection — June 2023
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
Dear Ms. Drummond:
On June 15 and 21, 2023, representatives from S&ME, Inc. (S&ME) performed a visual inspection of the landfill
cover and the storm water/surface water conveyance features at the closed Sorrell Landfill located in Apex, North
Carolina. This letter report is provided to document the findings of our inspection. Services conducted by S&ME
were performed in general accordance with the following:
S&ME Proposal No. P4258-07V, dated April 25, 2007,
S&ME's memorandum 2023 Landfill Cover Maintenance Cost Estimate, dated April 28, 2023, and
NCDEQ memorandum Authorization to Conduct the Spring 2023 and Fall 2023 Landfill Cover
Maintenance Activities Closed Sorrell MSW Landfill, dated May 24, 2023.
BACKGROUND INFORMATION
Sorrell Grading Company initially operated a construction and demolition (C&D) landfill at this site, which
subsequently also accepted municipal solid wastes (MSW) and similar waste materials. A Closure Plan and a Post -
Closure Plan for the landfill were prepared by Stuart Jones Consulting Engineering, dated June 20, 1996 and
submitted to the Section on behalf of Sorrell Grading Company. The Closure Plan provided criteria for the
construction of a landfill cover consisting of a clay cap over the top 24 acres of the landfill and a vegetative layer
of the top and side slopes of the landfill. The Closure Plan indicated that the side slopes were already largely
constructed at that time and that the cap construction was underway.
A Closure Report, dated September 7, 2001, was prepared by S&ME and submitted to the Section on behalf of
Sorrell. The report detailed S&ME's evaluation of the landfill cover after the landfill had been closed and the clay
cap had been placed on top of the landfill. The Closure Report described testing of the cover on the top and the
side slopes of the landfill, verifying the placement and thickness of the infiltration layer and the erosion layer.
Locations on the side slopes and the top of the landfill were tested. Most of the locations were found to contain
adequate thicknesses of cap material. Where the thickness of the cap was insufficient, these locations were
identified, and repairs were to be made by the owner. Additional information on the construction and condition of
S&ME, Inc. 13201 Spring Forest Road I Raleigh, NC 276161 p 919.872.2660 1 www.smeinc.com

Landfill Cover Inspection — June 2023
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
the landfill cover system was described in S&ME's letter report Response to Notice of Violations, submitted to
NCDENR-DWM on January 26, 2009.
The June 15 and 21, 2023 landfill cover inspection was limited to an evaluation of one area of compliance:
A visual inspection of the landfill cap over the top 24 acres of the landfill and the storm water/surface
water conveyance features. Cutting and maintenance was performed June 12th through June 13th, 2023,
by Heritage Landscape Services, Inc, subcontractor to S&ME, under a separate task.
S&ME personnel did not inspect the landfill side slopes which are covered by growths of pine trees, hardwoods
and underbrush.
OBSERVATIONS
Overall, the cap and stormwater conveyance features appear to be in good condition with adequate vegetation.
No deficiencies in need of corrective measures were observed. The following features were visually identified as 1)
deficient and in need of corrective measures, 2) as minor functional issues requiring monitoring or 3) as functional
and not in need of corrective measures. The numbered items below correspond to the numbers on Figure 1 and
to the numbered photos in the photographic log.
Deficiencies
No deficiencies were observed.
Minor Functional Issues
An apparent subsidence/shallow slope failure was observed on the northeast side of landfill, east of the
access road to MW-7 (photo 1). A scarp about 18 to 24 inches in height was present near the mid -point
of the exterior landfill slope. Soil within the scarp was dry.
The pipe which conveys stormwater beneath the southern access road appears have settled. Separation
between the pipe sections was visually observed and the pipe does not appear to lay straight, indicating
some settlement. Additionally, rip -rap stone previously below the outlet pipe has been pushed out from
beneath the stormwater discharge (photos 2a, 2b, and 2c).
Functional Items
Grass and vegetation across the landfill cap and roads looking west has been mowed. This maintenance
item has been completed twice a year over the past several years, substantially improving the vegetative
cover at the site. The grass and vegetation are currently an acceptable height (photo 3).
The road to monitor well MW-7 was mowed from the top of the landfill cap to the bottom of the hill and
appeared to be in good condition (photo 4).
S. Hillside slope has been mowed and appeared to be in good condition (photo 5).
6. The area of subsidence/slope failure on the hill appeared to have no change or movement since last
inspection (photo 6).
June 27, 2023 2

Landfill Cover Inspection — June 2023
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
The drainpipe at the west end of the landfill was not blocked by any substantial vegetation and appeared
functional (photo 7).
A low spot at the bottom of the hill, beside the southern access road was observed with standing water
during previous inspections. To promote drainage of standing water, this area was filled in with soil
during the Spring 2023 maintenance/repairs. (photo 8)
9. The property adjacent to the south/southwest of landfill has been cleared and is an active construction
site (photos 9a, 9b).
10. Ditch near boundary of landfill and monitor well 4 appeared to be in good condition (photo 10).
11. Inlet grate in the large sediment pond appeared to be in good condition and free of debris (photo 11).
12. Black flexible drainpipes were observed to be broken/disconnected during the November 2022
inspection. Pipes were repaired during the Spring 2023 maintenance event and appeared to be in good
condition (photo 12).
Road along southern property boundary has been mowed and appeared to be in good condition (photo
13).
14. Second set of black flexible drainpipes. These have been repaired since the last inspection and appear to
be in good condition (photo 14).
15. Entrance area gate and fence appeared to be in good condition (photo 15).
16. Vegetation growing on the back (western and northwestern) slope of the landfill cap looking upward
from the access road has been mowed (photos 16a and 16b).
The headwall structures at the entrance of the slope drains on the south slope were not blocked by any
substantial vegetation and are functional (photos 17a and 17b).
18. The vegetation growing in the drainage ditch running parallel to the landfill along the southern access
road has been removed and chemically treated (photo 18).
19. A depression with standing water was previously observed in the northeast area of the landfill cap. To
promote drainage of standing water, this area was filled in with soil during the Spring 2023 maintenance
event. (photo 19)
The approximate location of each of the above items is labeled on the attached Site Plan drawing (Figure 1).
RECOMMENDED CORRECTIVE MEASURES
There were no deficiencies observed, but S&ME recommends the following Minor Functional Issues should
continue to be monitored.
Minor Functional Issues:
1. The apparent shallow slope failure observed on the northeast side of landfill near MW-7 should continue
to be monitored for additional subsidence, movement, or erosion.
2. The pipe beneath the southern access road appears to be disconnected between one or more sections. It
was observed that the pipe does not lay straight and rip -rap stone beneath the pipe outlet has been
pushed from below the stormwater discharge.
June 27, 2023 3

Landfill Cover Inspection — June 2023
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
Functional Issues:
S&ME recommends that the landfill cap continue to receive regular, bi-annual mowing of the landfill cap in the
spring and fall to promote the health of the vegetative cover. Areas of settlement, and depressions, holding water
should continue to be identified, monitored, and repaired to promote water draining off the landfill cap and
minimize standing water above waste.
CLOSING
S&ME appreciates the opportunity to provide these services and hopes that you find this report to be complete
and informative. We would appreciate an opportunity to discuss our findings and recommendations with you.
Please call us at [phone] if you have any questions or comments, or if we can be of further assistance.
Sincerely,
S&ME, Inc.
Emily Hermann
Engineering Technician
[e-mail]
Attachments: Photographic Log
Figure 1 — Cover Inspection Site Map
Samuel P. Watts, P.G.
Senior Project Manager
[e-mail]
cc: Mr. James Easthom ([e-mail]) - Kennon, Craver, Belo, Craig & McKee, PLLC
Mrs. Teresa Sorrell Atkins ([e-mail])
June 27, 2023 4

Attachments

iew of the pipe beneath the road near MMW-4. Appeared to
a be sinking into the ground.
another view of the pipe between the road near MMW-4.
nternal view of pipe shows slight curve in pipe.
0 Site Photographs - June 2023 Landfill Cover Inspection S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: S. Watts Date Taken: 6/15/23
Apex, Wake County, North Carolina

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3
iew of the landfill cap grass and vegetation. Mowed and in
good condition.
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View of the hillside slope. Vegetation appeared to be mowed
and in good condition.
0 Site Photographs - June 2023 Landfill Cover Inspection S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: S. Watts Date Taken: 6/15/23
Apex, Wake County, North Carolina

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ew of drainage pipe at the west end of landfill. Appeared to be
?e of blockage and in good condition.
.V
9a iew of property south of landfill under development. Methane
monitor well MMW-5 (foreground) in good condition.
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View of a low spot at the bottom of the hill beside the access
road near the southern part of landfill.
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9bView
of adjacent property south of landfill under development.
Looking southwest near methane monitor well MMW-6.
0 Site Photographs - June 2023 Landfill Cover Inspection S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: S. Watts Date Taken: 6/15/23
Apex, Wake County, North Carolina

11 iew of outfall in sediment pond. Free of any major debris.
13riew of road along southern property boundary. Appeared to bE
owed and in good condition.
0 Site Photographs - June 2023 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _= Sorrell Landfill Taken by: S. Watts Date Taken: 6/15/23
Apex, Wake County, North Carolina

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14 View of second set of black flexible drainpipes. Recently repaired
and appeared to be in good condition.
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16 a
View of the recently mowed back (western) slope of the landfill
cap looking upward from the access road.
15 /iew of the entrance area gate and fence
16b r1aew
of the recently mowed back (northwestern) slope of the
ndfill cap looking upward from the access road.
0 Site Photographs - June 2023 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _= Sorrell Landfill Taken by: S. Watts Date Taken: 6/15/23
Apex, Wake County, North Carolina

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View of Slope Drain #1 Inlet/ Headwall.
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18View
of the drainage ditch running parallel to the southern
landfill boundary.
(Looking east)
17b (View of Slope Drain #2 Inlet/ Headwall.
119 (Looking southwest at soil placed in depression with standing
ater that was previously observed in November 2022 in the
0 Site Photographs - June 2023 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _= Sorrell Landfill Taken by: S. Watts Date Taken: 6/15/23
Apex, Wake County, North Carolina

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