0403_AnsonLF_CommentsPh5_20221021

From: Wilson, Donna J
Sent: Friday, October 21, 2022 5:57 PM
To: Susan Reid; Tyler Fitzgerald; Bivins, Nathan
Cc: Bradford, Teresa; Stanley, Sherri
Subject: Anson Landfill PTC Phase 5 preliminary comments
Attachments: SeismicUnstable from 1119_DukeAsheville.pdf, Seismicl-eachate calcs from 1119_DukeAsheville2.pdf,
seismic veneer slope stability from 1119_DukeAsheville.pdf; SeismicUnstable from 1119
_DukeAsheville.pdf
Hello Susan, Tyler, and Nathan,
Below are preliminary comments on the PTC for Phase 5.
1. Seismic impact zones — Provide demonstration that all containment structures, including liners, leachate
collection systems, surface water control systems, and final cover are designed to resist the maximum horizontal
acceleration in lithified earth material for the site. Attached are example seismic calculation pages from another
permit, Duke Asheville landfill, permit 1119. The complete document can be viewed here, Doc ID 1360676,
dated 11-1-2019 -
https://edocs.deg.nc.gov/WasteManagement/Browse.aspx?id=732019&dbid=0&repo=WasteManagement.
2. The Phase 5 PTC application is also a vertical expansion application over the previous Phases. An additional 70
feet is added to the overall height of the landfill, from the previous maximum height. The additional weight
affects the older filled cells, for example, settlement and leachate pipe loading. Address the additional
weight/volume to the older cells with specific information of those cells.
3. Settlement calculations — Provide settlement calculation for the center of the landfill and other areas not yet
represented, to show that the 4-foot separation distance is met to SHGT and bedrock, and to demonstrate that
the subgrade will continue to have a minimum 2% slope. A drawing showing all the calculated points is
needed. The waste density used was 60 Ib/CF (1620 Ib/CY).
4. Explain the leachate pipe design for phase 4, cell 3, with the ability to collect leachate to meet the rules, and the
ability to clean out, camera, and jet clean. Of concern are the two lines with odd changes in elevation, one along
the north edge and one just below that on the north flat part of elevation 310-312. Also, there are multiple
leachate lines longer than 1000 feet. The slope of the landfill base is required minimum 2% after settlement.
5. Geomembrane liner installation testing should include an evaluation of the entire liner for leaks as required by
G.S. 130A-295.6(h)(1) using technology such as electronic leak detection.
6. In the application beginning text and figures, on pdf page 11, Figure 1-3 shows the property boundary and the
300-foot buffer in purple lines. On the north end, the buffer line crosses within the waste boundary.
7. App. C — Engineering calculations - For the pipe loading calculations, the waste density used is 41.44 Ib/CF (1119
Ib/CY). From the annual reports, the density would be about 1700 Ib/CY. PDF page 452.
8. Operations Plan — Discuss each of the alternate daily covers used. For the ones that are approved in the Section
guidance document "Approved Alternative Daily Cover Material For use at Sanitary Landfills," confirm
implementation according to the guidance (page 2) that includes a notice in the operating record with the
procedure and the notice and procedure sent to the Section. The guidance document is here -
https://edocs.deg.nc.gov/WasteManagement/0/edoc/723214/ApprovedACM Rev1 GDE 20170721.pdf?search
id=f7d5b34c-664b-4338-930a-d1db93f0272f. If the seaboard solids (used sawdust absorbent) are still being
used for alternate daily cover, provide details and procedure in the text, and follow with the notice in the
operating record and to the Section, as described in the guidance document. Details should include specifics
such as the usage criteria listed in the guidance document.
9. The operating plan, and App. G, indicates that leachate may be recirculated within in the landfill by spraying
onto the active working face. If this a currently active practice, provide information on volumes and dates for
the amounts being recirculated, within the last 2 or 3 years.

10. For the operational berms, or inter -cell berms, describe the design and method. Describe how the flap will be
removed and the valve opened. Confirm that a written certification for the proper connection (flap removed,
valve opened) will be placed in the operating record, each time a cell is connected.
11. App. C — Engr. Calculations — update the lifespan study for life (years) of each phase. The in -place density used
was 1120 Ib/CY which seems low. From the annual report numbers, it would be about 1700 Ib/CY. PDF page
237.
12. In the appendices, update to the latest approved landfill gas monitoring plan and water quality monitoring plan.
13. Drawings — update the phase sequencing and changes in design. Provide detail drawing of the landfill gas
collection well on the final cover.
Additional comments will be sent as I complete my review. If you have any questions please let me know.
Donna
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Donna J_ Wilson
Engineering Project Vfanager, .valid Waste Section
Division of ff ante Management
Forth Carohna Department of Environmental Quality.
919_707.8255 (Office)
D onna - Wi Isonrdnedear_gov
Physical Address: 217 West Jones Street, Raleigh NC 2 7603
flailing address: 1545 Mail Service Center, l aleighNC 7699