9204_Wale_Sorrell_MSWLF_LFCoverMaint_FID1837599_20240510

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May 10, 2024
Solid Waste Section
NCDEQ Division of Waste Management
217 West Jones Street
Raleigh, North Carolina 27603
Attention: Ms. Jackie Drummond via email: [e-mail]
Hydrogeologist
Reference: Landfill Cover Inspection — May 2024
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
Dear Ms. Drummond
On May 3, 2024, 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 waste (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
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.
S&ME, Inc. 13201 Spring Forest Road I Raleigh, NC 276161 p 919.872.2660 1 www.smeinc.com

Landfill Cover Inspection — May 2024
Sorrell Landfill (Permit #92-04)
�. Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
The April 2024 landfill cover inspection was limited to an evaluation of one area of compliance:
1. A visual inspection of the landfill cap over the top 24 acres of the landfill and the storm water/surface water
conveyance features. Mowing and maintenance was performed on April 22-24, 2024, by Carolina Outdoor
Services, LLC, 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
There were no features identified as deficient and in need of corrective measures.
Minor Functional Issues
1. On the northern slope of the landfill on the road to monitor well MW-7, the slope is hummocky and the slope
east side of the road has some dislodged trees, indicating subsidence/slope failure (photos 1 a and 1 b).
2. The pipe which conveys stormwater beneath the southern access road appears to 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 was installed below the outlet pipe. (photo 2a and 2b).
3. A possible area of subsidence was observed on the southern slope to the north of MW-8 and DW-1. A hole of
approximately 24 inches in diameter was observed on the slope (photo 3).
Functional Items
4. 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 at an acceptable height (photo 4).
5. The road to MW-4 was clear and appeared to be in good condition (photo 5).
6. The road to MW-7 has been mowed and appeared to be in good condition (photo 6).
7. Slope drain #2 has been mowed and appeared to be in good condition (photo 7).
8. Slope drain #1 has been mowed and appeared to be in good condition (photo 8).
9. The southern property boundary road has been mowed and cleared of vegetation. The rip rap ditch has been
chemically treated and cleared of vegetation. The fence remains in good condition (photo 9).
10. Flexible corrugated plastic drainpipes from slope drain #1 appeared to be in good condition (photo 10).
11. Flexible corrugated plastic drainpipes from slope drain #2 appeared to be in good condition (photo 11).
May 10, 2024 2

Landfill Cover Inspection — May 2024
Sorrell Landfill (Permit #92-04)
Z
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
12. Reinforced concrete pipe (RCP) that conveys water beneath the southern property boundary road was cleared
of vegetation and appears to be in good condition (photo 12).
13. Site development activities were observed on the south adjacent property (photo 13).
14. Inlet for diversion ditch/diagonal water bar no. 2 was cleared of vegetation and appears to be functional
(photo 14).
15. The road to MW-5 along the western edge of the appeared has been mowed, cleared of vegetation, and
appears to be in good condition (photo 15).
16. The sediment pond drain has been cleared of debris. The pond is as normal pool elevation (photo 16).
17. In March 2024, during methane monitoring activities, the pipe beneath the access road to MW-9 was
observed to be clogged and there was visual evidence the creek had washed over the road. During the April
2024 maintenance the contractor cleared debris from the mouth of the pipe and regraded the road (photo
17a). This is a heavily wooded area and the creek/pipe is susceptible to limbs and logs washing in. Photo 17b
is looking downstream from the pipe/creek crossing and photo 17c is looking upstream beneath from the
road/creek crossing.
18. The road to MW-9 has been mowed, cleared of vegetation, and appears to be in good condition. (photo 18).
19. Location of the former slope failure is well -established and has been mowed (photo 19).
20. The adjacent west property is a potential access point for trespassers (photo 20).
21. The internal access road from the southern property boundary road has been mowed and cleared (photo 21).
22. The slope has been mowed and is well -established (photo 22).
23. The main entrance gate off Smith Road is secured with a chain -link fence, gate, and lock (photo 23).
The approximate location of each of the above items is labeled on the attached Site Plan drawing (Figure 1).
RECOMMENDED CORRECTIVE MEASURES
S&ME recommends the following corrective measures for each observed item:
Deficiencies
1. No deficiencies were identified during the April 2024 landfill cover inspection.
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.
During the April 2024 maintenance 3 tons of rip rap was added to the area beneath the pipe to minimize
erosion of the ditch and continued settlement of the pipe. The pipe should continue to be monitored
settlement and erosion.
3. The possible subsidence observed on the slope to the north of MW-8 and DW-1 should be monitored for
additional subsidence, movement, or erosion.
May 10, 2024

Landfill Cover Inspection — May 2024
Sorrell Landfill (Permit #92-04)
I I 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. It is recommended site development of the property south and adjacent to
the landfill continue to be monitored.
Items #13 and #15, noted above indicate potential additional points of entry to the landfill, besides the main
entrance from Smith Road. As development continues to encroach on the landfill, additional security measures
(e.g., fence, berm, or gate) may be required to secure the site, prevent unauthorized entry, and meet the
requirements of Section 15A NCAC 13B (North Carolina Solid Waste Rules).
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 contact the undersigned if you have any questions about our report, or if we can be of further assistance.
Sincerely,
S&ME, Inc.
T
Jennifer Petzold
Project Administrator
[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])
May 10, 2024 4

Attachments

iew to west along the northern slope of the landfill, from the road to
1 a MW-7 of mature, upright trees and the hummocky ground surface.
Interior of pipe that conveys water beneath the southern
2a
property boundary road.
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View to east along the northern slope of the landfill, from the
road to MW-7 of the hummocky ground surface and dislodged
trees.
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2 b
Riprap stone added at the exit of (below) the pipe out -fall at the
southern property boundary.
0 Site Photographs - April 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _= Sorrell Landfill Taken by: S. Watts Date Taken: 5/3/24
Apex, Wake County, North Carolina

0 Site Photographs - April 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: S. Watts Date Taken: 5/3/24
Apex, Wake County, North Carolina

a
v to the east along the southern property boundary road.
d and ditch have been mowed and cleared of vegetation.
Q �/iew of slope drain no. 1 which has been mowed and cleared of
10 View of black flexible drainpipes from slope drain no.1.
0 Site Photographs - April 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _ Sorrell Landfill Taken by: S. Watts Date Taken: 5/3/24
Apex, Wake County, North Carolina

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11 �iew of black flexible drainpipes from slope drain no.2
13 iew to the south of the south adjacent property - site
development.
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12 Reinforced concrete pipe (RCP) that conveys water beneath the
southern property boundary road cleared of vegetation.
0 Site Photographs - April 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _= Sorrell Landfill Taken by: S. Watts Date Taken: 5/3/24
Apex, Wake County, North Carolina

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15 View of the road to MW-5 has been mowed and cleared of
vegetation.
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16 of the drain at the sediment pond has been cleared of
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ebris; the water level is normal pool elevation.
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17b viewto the west and downstream of the pipe beneath the road
o MW-9.
0 Site Photographs - April 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: S. Watts Date Taken: 5/3/24
Apex, Wake County, North Carolina

1 7c View to the east and upstream of the pipe beneath the road to
�MW-9
19 liew to the south looking uphill at the vegetated slope former
ocation of slope failure.
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18 iew looking east along the access road to MW-9. The road is
clear of vegetation and in good condition. (MW-9 is in the
20 rest view of the path from the adjacent property to the west.
0 Site Photographs - April 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _= Sorrell Landfill Taken by: S. Watts Date Taken: 5/3/24
Apex, Wake County, North Carolina

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View of the cleared internal access road from the southern
property boundary road up to the landfill cap which has been
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iew of the main entrance gate off Smith Road.
0 Site Photographs - April 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
III _= Sorrell Landfill Taken by: S. Watts Date Taken: 5/3/24
Apex, Wake County, North Carolina

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