9204_Wake_Sorrell_MSWLF_LFCoverMaint_20241216

December 13, 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 — November 2024
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
Dear Ms. Drummond
On November 13, 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 January 4, 2024, and
NCDEQ memorandum Authorization to Conduct the Spring 2023 and Fall 2023 Landfill Cover Maintenance
Activities Closed Sorrell MSW Landfill, dated May 4, 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 — November 2024
Sorrell Landfill (Permit #92-04)
�. Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
The November 2024 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. Mowing and maintenance was performed on November 4-6, 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
One of the flexible corrugated drainpipes from slope drain #1 is broken. Also, one of the pipes does not reach
the drainage ditch (Photos 10 and 22).
Minor Functional Issues
2. 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).
3. 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).
4. 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
5. Grass and vegetation across the landfill cap and roads looking west have 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).
6. The road to MW-4 was clear and appeared to be in good condition (photo 5).
7. The road to MW-7 has been mowed and appeared to be in good condition (photo 6).
8. Slope drain #2 has been mowed and appeared to be in good condition (photo 7).
9. Slope drain #1 has been mowed and appeared to be in good condition (photo 8).
10. 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).
11. Flexible corrugated plastic drainpipes from slope drain #2 appeared to be in good condition (photo 11).
December 13, 2024

Landfill Cover Inspection — November 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. During the November 2024 site visit, there was no debris at the mouth of the pipe and the regraded road
appeared to be in good condition (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 internal access road from the southern property boundary road has been mowed and cleared (photo 20).
21. The slope has been mowed and is well -established (photo 21).
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
The black flexible drainpipe from slope drain no. 1 needs to be replaced and to extend down to the drainage
ditch below.
Minor Functional Issues:
1. The apparent shallow slope failure due to dislodged/leaning trees was observed on the northeast side of
landfill near MW-7. It 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, three 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 for
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.
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
December 13, 2024

Landfill Cover Inspection — November 2024
Sorrell Landfill (Permit #92-04)
Z
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
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.
Jonathan Olanin
Environmental Scientist I
[e-mail]
M: 984.303.9791
Attachments: Photographic Log
Figure 1 — Cover Inspection Site Map
Samuel P. Watts, P.G.
Senior Project Manager
[e-mail]
M: 919.8019.4920
cc: Mr. James Easthom ([e-mail]) - Kennon, Craver, Belo, Craig & McKee, PLLC
Mrs. Teresa Sorrell Atkins ([e-mail])
December 13, 2024 4

Attachments

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View to the west along the northern slope of the landfill, from
the road to MW-7 of mature, upright trees and the hummocky
around surface.
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2a Interior of pipe that conveys water beneath the southern
property boundary road.
Site Photographs - November 2024 Landfill Cover Inspection S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: A. Bentz Date Taken: 11/13/24
Apex, Wake County, North Carolina

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of possible subsidence observed on the southern slope,
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Site Photographs - November 2024 Landfill Cover Inspection SWE Project No. 1054-07-251
Sorrell Landfill Taken by: A. Bentz Date Taken: 11/13/24
Apex, Wake County, North Carolina