9204_Wake_Sorrell_MSWLF_LFCoverMaint_FID1767771_20230115

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January 11, 2023
Division of Waste Management
217 West Jones Street
Raleigh, North Carolina 27603
Attn: Ms. Jackie Drummond via email: [e-mail]
Reference: Landfill Cover Inspection — November 2022
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
Dear Ms. Drummond:
On November 4, 2022, 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 S&ME Proposal No. P4258-07V, dated April 25, 2007, S&ME's
memorandum 2022 Landfill Cover Maintenance Cost Estimate, dated March 25, 2022, and the NCDEQ
memorandum Authorization to Conduct the Spring 2022 and Fall 2022 Landfill Cover Maintenance Activities Closed
Sorrell MSW Landfill, dated March 29, 2022.
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
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 2022
Sorrell Landfill (Permit #92-04)
�. Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
The November 4, 2022 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 October 21 through October 23,
2022, 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.
Three 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
A slope failure was observed on the upper portion of the steep slope on northwestern portion of the
landfill property (photograph 1 & 2). The slope failure was reported in the last nine cover inspections
S&ME performed for the site.
2. Along slope drain No. 2, the inlet near the southern access road appears is disconnected. (photo 3).
3. A depression with standing water was observed along the east side of the base of the access road on the
southwestern portion of the landfill cap, where the southern access road connects the landfill cap to the
southern border of the landfill. Evidence of this standing water was previously observed during S&ME's
November of 2018, June 2020, and October 2020 inspections. During the May 2021 maintenance, soil
and gravel was placed in the depression to promote water drainage. When S&ME inspected the area in
June 2021 and December 2021, some standing water was again observed within the depression and
adjacent access road. On June 8, 2022 Heritage installed a flexible drainpipe in the depression to
transport the water under the access road and the depression was drained of standing water. During
S&ME's inspection on June 14, 2022 and the current inspection, November 4, 2022, standing water has
still remained present in the depression (photo 4).
4. A depression with standing water was observed in the northeast area of the landfill cap (photos 5 and 6).
5. Along the north side of the 2009 slope and regrading repair, slope drains are ripped and disconnected
(photos 7 and 8).
Minor Functional Issues
The stormwater outfall for the pipe that drains the stormwater ditch, parallel to the southern access road,
appears to be functioning based on evidence of water flow. However, sections of the concrete pipe
beneath the southern access road appear to be separated and the pipe has settled on the discharge end.
Furthermore, evidence of scouring was visible below the discharge end of the culvert (photo 9).
August 6, 2021

Landfill Cover Inspection — November 2022
Sorrell Landfill (Permit #92-04)
I I Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
Functional Items
7. Inlets for diversion ditch/diagonal water bar no. 1 & no. 2 were not obstructed by vegetation and appear
to be functional and are preventing erosion of the access road (photo 10).
8. Evidence of vehicular traffic has been observed on the landfill. These vehicles appear to be accessing the
landfill via an access road from an adjacent natural gas easement (photo 11).
9. The inlet and outfall of the flexible slope drain at the western tip of the landfill is functional and free of
significant vegetation build-up (photo 12).
10. The culvert pipe conveying runoff under the access road just west of MW-6 is now functional (photo 13).
11. The outfall in the sediment pond is functional and free of any major debris (photo 14).
12. The access roads to monitor well MW-4 and MW-7 were observed to have to have been cleared and are
functional (photos 15 and 16).
13. The gravel access road traveling around the base of the landfill appeared to be in good condition. (photo
17)
14. Grass and vegetation across the landfill cap and roads 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 an acceptable height (photo 18)
The vegetation growing on the western hill slope of the landfill cap has been mowed and removed from
the slope (photographs 19 and 20).
16. 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 21 and 22).
17. The vegetation growing in the drainage ditch running parallel to the landfill along the southern access
road has been removed and chemically treated (photos 23 and 24).
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 slope failure should be evaluated by a qualified professional to determine the cause of the failure
and repaired according to their recommendations to prevent further damage to the landfill cap, soil
erosion, or exposure of waste.
Along slope drain No. 2 inlet to the southern access road appears to be disconnected. The plastic flexible
slope pipe should be repaired to promote surface water draining off the landfill cap.
The area of subsidence collecting surface water at the base of the landfill has consistently been observed
to have standing water in consecutive inspections. During the June 2022 maintenance, a flexible
drainpipe was placed in the depression and run under the access road to the drainage ditch on the
southside of the road to promote water drainage. When S&ME inspected the area on June 14, 2022 and
the current inspection, November 4, 2022, some standing water remained within the depression. This
area should be further repaired to continue to promote drainage.
August 6, 2021

Landfill Cover Inspection — November 2022
Sorrell Landfill (Permit #92-04)
Apex, Wake County, North Carolina
S&ME Project No. 1054-07-251
A depression with standing water was observed in the northeast area of the landfill cap. This area should
be further repaired to continue to promote drainage.
Along the north side of the 2009 slope and regrading repair, slope drains are ripped and disconnected.
The plastic flexible slope pipe should be repaired to promote surface water draining off the landfill cap.
Minor Functional Issues:
The disconnected joint in the pipe should be monitored for evidence of scouring or erosion between the
joints. Should the level of erosion or scouring reach levels where it could impact the integrity of the road,
the pipe should be repaired or replaced.
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.
James A. Waters Samuel P. Watts, P.G.
Environmental/Industrial Hygiene Technician Senior Project Manager
[e-mail] [e-mail]
Attachments: Photographic Log
Figure 1 — Cover Inspection Site Map
cc: Mr. James Easthom - Kennon, Craver, Belo, Craig & McKee, PLLC (jeasthom0ken noncraver.com)
Mrs. Teresa Sorrell Atkins ([e-mail])
August 6, 2021 4

Attachments

Site Photographs S&ME Project No. 1054-07-251
I I = Sorrell Landfill Taken by: S. Watts Date Taken: 11/4/2022
Apex, Wake County, North Carolina

Depression with standing water that was observed in the
northeast area of the landfill cap, looking southwest.
of the 2009 repair slope drain inlets on the northeast side.
6
Another view of the standing water that was observed in the
northeast area of the landfill cap, looking west.
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View of the 2009 repair slope drains that have been ripped and
disconnected on the northeast side.
Site Photographs S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: S. Watts Date Taken: 11/4/2022
Apex, Wake County, North Carolina

9
View in the pipe that drains the stormwater ditch. Sections of the
concrete pipe beneath the southern access road appear to be
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11 View of off -site access path coming onto the property from the
west. Appears to have been used recently.
Site Photographs S&ME Project No. 1054-07-251
Sorrell Landfill Taken by: S. Watts Date Taken: 11/4/2022
Apex, Wake County, North Carolina

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