2906-DavidsonCountyMSWLF_PTC_Phase2_Area3_Eng_comment_DIN28566_20171027

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Chao, Ming-tai
From:Chao, Ming-tai
Sent:Friday, October 27, 2017 2:34 PM
To:'[e-mail]'
Cc:'[e-mail]'; Pieter Scheer ([e-mail]);
Heim, Susan A; Aja, Deborah; Sugg, William P
Subject:Engineering Comments (DIN 28566) on the PTC-Phase 2, Area 3 for Davidson County
MSWLF, 29-06
Dear Mr. Buck:

On October 06, 2017 the Solid Waste Section (the SWS) received the Permit to Construct Application (the
Application) for the lined Davidson County Landfill – Phase 2; Area 3, Permit No. 2906-MSWLF-2008. The
engineering portions of the Application (DIN 28523) was completely reviewed, below are the comments (DIN
28566) on the Application. The SWS Hydrogeologist is reviewing the monitoring plans and design
hydrogeological study report (Attachments I, J , & K of the Application); he may send you comments, if any, on
the above-referenced plans/report in a separate correspondence.

DIN 28566
Comments, Davidson County MSWLF, PTC Application - Phase 2, Area 3 (DIN 28523)

Attachment A - General Information
1. (Transfer Station, on Page 3) The C&D wastes received in the transfer station is shipping to a C&D
recycling facility.
i. Descriptions of the facility, size/dimensions, covered and uncovered area, tipping floor and
loading bay, traffic route – ingress and egress, etc.

ii. Is the C&D recycling facility an off-site permitted facility?

Attachment B - Facility & Engineering Plan
2. Provide the descriptions of the on-site transfer station in the Facility& Engineering Plan including the
size of the building (covered and uncovered areas), building features (closed and unclosed portions,
loading bay, push walls), tipping floor material and leachate management devices (sloped tipping floor,
floor drains, sumps, etc.), utility (including water source for routine cleaning use) and ventilation, etc.

3. The waste footprint for each area (in acreage) in Table 2.1 shall be consistent with that on the Drawing
No S2/ Sheet No. 3.

4. (Table 2.1, Section 1.1 on page 2, & Appendix A) Please provide the consistent acreage of Phase 3
throughout the Permit Application. Table 2.1 shows Phase 3 of 14.5 acres, but the sum of Phase 3 Cell 1
(8.65 acres) and Cell 2 (5.88 acres) is 14.53 acres. 14.6 acres is mentioned in Section 1.1.

5. (Table 2.3 & Appendix A) The volume required for the 18-inch-thick compacted soil liner at each area
(Area 3 through Area 8) lists in Table 2.4 is inconsistent with that in Appendix A. Please verify.

6. (Table 2.4 & Appendix A) The volume required for the protective cover at each area (Area 3 through
Area 8) lists in Table 2.4 is inconsistent with that in Appendix A. Please verify.
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7. (Section 2.2.2) the AUF of 0.6 states in Section 2.2 and Appendix A. But the bac calculation of the data
in Appendix A shows the AUF being used is about 0.667. The variation of AUF (.06 vs .0667) will
impact the life expectancy present in Appendix A and Table 2.1. Please double check the AUF used in
the calculations in Appendix A.

Attachment C- Technical Specifications
8. Typical components of the landfill gas collection and control system (LFGCCs) are shown on Drawing
No. LG1/Sheet No 20. Should the material and construction of the LFGCCS be included to the
Attachment C?

9. (Section 02110 Site Preparation) Is there any reason why the requirement for the Contractors to submit
the location(s) for disposal of clearing and grubbing debris is removed from Part C. Submittal? There is
no permitted yard waste/composting unit at landfill facility and no open burning clearing debris is
specified in this Section; therefore, it is necessary to know where the waste goes to.

10. (Section 02223 Embankment) Should the Contractors submit the Engineer the soil testing results of a
soil borrow(s) including soil type (ASTM D 2487) and density and moisture relationship (ASTM D 698)
which are specified in this Section?

11. (Section 02250 Soil Liner) Since the ASTM D400 is withdrew and replaced by ASTM D 6913, the
revision is required in Paragraph A.3.

12. (Section 02776 GCL, Paragraph C) The Contractor/manufacturer of GCL must submit a certification /
report of summarizing or finding if broken needles in the supplied GCL products were detected and
removed.

13. (Section 02782 Geosynthetic Rain Cover) Please provide the specification to temporarily anchor or
ballast down the cover material damaged by against wind lift in Paragraph B.5.

14. (Section 11314 Leachate Pumps & Controls) The elevations of pump stages – Alarm, LAG Pump On,
Pump On/Off, and Base of Pump as shown on Detail 5/LM2 of Sheet No.12 should be a portion of the
as-built drawings both post inside control panel (Paragraph B.q.) and the CQA Report.

Attachment E – Operations Manual
15. The Area 3 will be divided into two cells – Cell 1 & 2 which will be subdivided into Cells 1A, 1B & 1C
and Cells 2A & 2B, respectively. Please provide the construction and operation sequences in the
Operations Manual.

16. According to google map, it looks like the West Borrow Area on the west side of the closed MSWLF
unit – Phase 1 has been used a yard waste collection site or a composting unit. If the County conducts
the yard waste collection or composting activity, pleased add the waste operations to the Operations
Manual. The waste operation unit must be added to the site plan drawing as well.

17. (Section 1.6) Please provide fire prevention requirements for the on-site Transfer Station:
i. The descriptions of procedures to manage “hot load.”

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ii. Is there any water source connecting to the transfer station? Or is there a fire suppression system
installed in the station.

18. (Section 1.9) The certified and trained staff(s) must be present while the transfer station is receiving
wastes.

19. (Section 1.10.2) Should the safety vest and steel -toe shoes/boots be part of the required PPE for the
landfill personnel?

20. (Section 1.12) The leachate records are described in Section 3.2.3. Please correct the typo.

21. (Section 2.1.2) The listed C&D wastes may only be acceptable at the transfer station if the collected
wastes are transferring and ultimately disposed of at a permitted MSWLF or a C&DLF. Since the
County intends to utilize the transfer station shipping C&D wastes to material recovery facilities, should
the types of recoverable or recyclable C&D wastes that are permitted to be received at an off-site
treatment and processing facility (such as Abby Green) be listed in this Section?

22. (Sections 2.1.2 & 2.2.1) The Section 2.1.2 describes that land clearing waste can be accepted as a C&D
waste at the transfer station, but the Sections 2.2.1 & 2.2.2 state that yard waste and yard trash are
prohibited wastes which can’t be accepted at the transfer station. Please not that yard waste - as defined
in Rule NCAC 13B .0101(56) includes yard trash & land clearing wastes such as stumps, limbs, leaves,
grass, and untreated wood. Clean wood waste is redirected to a nearby treatment and process facility
owned a private company as mentioned in Section 2.0. Abby Green is not a permitted composting
facility, and Davidson County Landfill Facility is not operating a permitted yard waste collection site or
composting unit. Please clear define that yard trash and yard waste including LCID wastes (except clean
inert debris – concrete, rock, brick, etc.) can’t be accepted in the transfer station. If the County wants to
operate a yard waste collection site or a composting unit, please revise the Permit Application
accordingly.

23. (Section 2.2) Asbestos containing material or waste (ACM) must be listed as a prohibited waste and
can’t be accepted at the transfer station except the County has certified by the NC Health Department to
handle ACM at this transfer station.

24. (Section 2.3.1) Since the waste receiving and inspection is applicable to both landfill disposal, waste
transfer activities, and convenience center/citizen drop-off area.
i. Please describe the waste screening processes/protocols at the transfer station from the scale
house to the tipping floor.

ii. Refer the Section 2.7 that trained landfill staffs at the convenience center/citizen drop-off area to
conduct the waste screening and to direct waste placement at the designated locations/storage
units?

25. (Section 2.6) please additional info of transfer station operations:
i. A narrative description of the operation from the truck arriving at the site, through all steps of the
transfer station operation, to the point of waste removal. Describe traffic flow and procedures for
loading and unloading of waste.

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ii. Please describe the final destinations for the collected wastes – MSW and C&D wastes at this
transfer station.

26. (Section 2.6.7) If the recovered inert debris will be stored on site and used as beneficial fill material, as
defined in Rule 15A NCAC 13B .0562, please show the stockpile location on the drawing and describe
the annually maximum quantity (in cubic yard) and extent (in acreage) of the stockpile/unit. The 75% of
the recovered material must be used annually per NCGS 130A-309.05(c).

27. (Section 3.1) The surface water run-on and run-off control are applicable to both landfill unit and the
transfer station. Please describe the stormwater and leachate separation measures and run-on & run-off
control measures associated with the operations and the transfer station such as roofed structures, sloped
tipping floor etc.

28. (section 3.2) Please provide a copy of a permit or a document, issued by a local or public-owned
wastewater treatment work/plant, of approval of receiving leachate/wash down water generated from the
landfill facility.

29. (Section 3.3) Please provide additional info associated leachate management at the on-site Transfer
Station.
i. What is the holding tank capacity?

ii. The details and layout of the leachate management devices – such as floor drain(s), leachate
piping alignment, holding tank (capacity), etc.

iii. Please provide the copy of approval document of accepting leachate generated from the landfill
units and the transfer station.

iv. Please provide the inspection frequency for leachate management devices – such as floor
drain(s), sump(s), and the holding tank.

v. Please provide the frequency of cleaning the holding tank.

30. (Sections 3.5.1 or 3.11) Please provide additional info [Rule 15A NCAC 13B .1626(5)(a)]
i. Please describe the approaches to manage condensate/leachate that is generated from the on-site
LFGCCs and LFGTE.

ii. A copy of the current and valid air quality permit (Title V- Permit No. 10408T001) issued by the
NC Division of Air Quality for operating the on-site flare and gas engines.

iii. Is the landfill facility subject to the annual Greenhouse Gas Reporting?

iv. Is there a copy of the rule-required operations and maintenance plan for the LFGCCs/LFGTE
being placed in the landfill operating record?

31. (Section 3.12) Per Rule 15A NCAC 13B. 1604(b)(2)(L)(iii), the County shall report leachate seep/breakout
within 24 hours after it occurred.

Appendix E – HHW Plan
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32. (Section 2.2) Please provide a copy of the typical survey form used for this HHW facility.

33. (Sections 2.6 & 2.11) Please provide a drawing or sketch to show designated location of each waste
storage unit and identification (such as flammable, corrosive, oxidant, used oil, pesticide, paints (oil-
base and latex) etc.) and secondary containments, if applicable inside the storage building and the
location of safety station (first aid, eye wash, and fire extinguisher, emergency contact info). This
drawing/sketch that is the vital tool for safety and emergency should be placed in the on-sit office and/or
area nearby the storage facility.

34. (Section 2.15) The HHW transporter may need to be registered / licensed by DOT and USEPA or NC
Hazardous Section. A waste manifest must be used to track wastes generation, transportation, and final
treatment, storage or disposal. The completed and signed manifests must be placed in the facility
operating record.

35. (Section 2.16) On or before August 1 of each year, the County should report the SWS the amounts of
HHW which are transported to off-site facilities for recycling, treatment, and/or disposal. Records must
be complied on monthly basis and maintained at the facility for inspection upon requested by the SWS.

36. (Section 2.18) Does the facility accept PCB-containing material or PCB wastes with concentrations less
than 50 ppm?

37. (Section 2.19) Please describe the closure notification including time to issue a written notification to the
DWM prior to conducting closure, the schedule for closure, final site inspection, etc.

38. (Section 3.0 Contingency Plan) Please provide additional information:
i. The contingency plan must be reviewed and approved by Davidson County Emergency
Management Services and Fire Marshal.

ii. Identify the nearby hospital/trauma center that can handle emergency related to the exposure of
hazardous waste and fire/explosion. The contact info including phone number and physical
address of the hospital/trauma center must be included in the plan and posted in the HHW
facility.

iii. Establish the route to the identified hospital/trauma center. The rout to hospital map must be
appended to the plan and post at the facility.

Attachment F – Closure and Post-Closure Plan
39. (Table 1-1 Closure Area and Capacity Summary) Please verify the proposed closure area (Phase 2 –
Area 1 through 3) and gross capacity which shall be consistent with those present in the Table 2-1 of the
Facility Plan and Drawing No. S1/Sheet No. 2.

40. (Table 2: MSWLF Phase 2 – Estimate Closure Cost) Please confirm the following data:
i. The total closure area. (41.1 or 41.2 acres).

ii. Please explain why the unit cost for the landfill gas well/vent is reducing from that in previous
cost estimate (May 2012).

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iii. Why is the unit price for installation and material of 40-mil LLDPE the same as 30-mil LLDPE
(in May 2012 cost estimates)?

Attachment H – Slope Stability, Settlement, and Bearing Capacity Evaluation
41. (Appendix A, Deep Seated Slope Stability Analysis) The interim / intermediate cover along Areas 1 & 2
is a 3 to 1 side slope as shown on Drawing No. FC1/Sheet No. 17. Since the future landfill development
piggybacking the Areas 1 & 2 will not occur approximately 8 to 10 years later according to the service
life expectation in Facility Plan. It is necessary to determine if the proposed 3 to 1 side slope is stable
within an acceptable safety margin which is concluded by a Slope Stability Analysis.

Attachment L- Drawing
42. (Drawing No. S5/Sheet No. 6) Is there any reason why not install a cleanout at each of three LCR piping
which parallel to the piping connecting riser pipe in the sump area? Without a cleanout these pipes can’t
be cleaning and camera video inspection as stated in Specification Section 02614.

43. (Detail 2/L2/Sheet 10) The typical detail of base liner system tie-in between Area 2 & Area 3 is correct
only if the alternative liner system is used at Area 3. The County may want add a typical detail of base
liner system tie-in between Area 2 & Area 3, if the standard liner system is used in Area 3.

44. (Detail 2/LM3/Sheet No. 13) Please make clarification for the following comments:
i. The force main should be the same material and diameter as that shown on Drawing No.
S7/Sheet No. 8.

ii. The force main alignment (southward) as shown on Detail 1 of Sheet No. 8/Drawing No. S7 will
extend and accommodate leachate generated from future areas of the landfill. Therefore, the one
end of force main on Detail 2/LM3may need to be terminated by a blind flange or cap.

45. (Detail 6/FC3 Sheet No. 19) Where is the seep collection trench located?
Please contact me if you have any questions on the comments; thank you and have a wonderful weekend.

Ming Chao
Ming-Tai Chao, P.E.
Environmental Engineer
Permitting Branch, Solid Waste Section
NCDEQ, Division of Waste Management
(Mailing Address)
1646 Mail Service Center
Raleigh, NC 27699-1646

(Street Address)
Green Square, 217 West Jones Street
Raleigh, NC 27603
Tel. [phone]
[e-mail]
http://portal.ncdenr.org/web/wm/sw

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