6804_OrangeCoCDLF_commentsonApplication_FID1275268_20190114

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Chao, Ming-tai
From:Chao, Ming-tai
Sent:Monday, January 14, 2019 5:15 PM
To:'Gordon Dively'
Cc:'Bruce Woody'; 'Tyrus Clayton'; Kirchner, Chuck; Lane, Ervin ([e-mail]);
Stanley, Sherri
Subject:Comments on the Orange County CDLF Permit Renewal application, 68-04
Dear Mr. Dively:

FID 1275268

I complete the initial review on the engineering portions of the permit amendment application (Life-of-site
permit application) (FID 1274690). The Solid Waste Section (SWS) Hydrogeologist is reviewing the water
quality monitoring plan and landfill gas monitoring plan right now, he will issue a separate comment as need.
Comments on the application is stated below for your review and responses.

SECTION I - Facility Plan
1. (Section 2.0, on Page 1-2)
i. Please provide the MSW Transfer Station name and permit number. The referenced Durham
County MSW Transfer Station is likely City Durham Transfer Station, Permit No. 3212-
Transfer-2014. Please verify.
ii. The referenced statute of the solid wastes that are prohibited from disposal in landfills shall be
N.C.G.S. 130A-309.10(f) and Rule 15A NCAC 13B. 542(e). Please correct the typos.
iii. Additionally, please add waste stated below to the prohibited waste list.
Used oil; antifreeze (ethylene glycol); aluminum cans; whole scrap tires, as provided in N.C.G.S.
130A-309.58(b); lead-acid batteries, as provided in N.C.G.S. 130A-309.70; motor vehicle oil
filters; recyclable rigid plastic containers; wooden pallets, except that wooden pallets may be
disposed of in a landfill that is permitted to only accept construction and demolition debris; oyster
shells; discarded computer equipment, as defined in N.C.G.S. 130A-309.131; and discarded
televisions, as defined in N.C.G.S. 130A-309.131.
iv. The referenced Rules for an industrial waste landfill shall be 15A NCAC 13B
.0503(2)(d)(ii). Please correct the typo.
2. (Section 3.1, on Page 1-7) The Section 1.0 states that Phases 4 & 5 will be a vertical extension of Phase
1 through 3; this statement is inconsistent with that in the second paragraph of Section 3.1. Please
clarify.
3. (Section 4.3) This section should described completion of the landfill gas trench (date of completion,
approximate dimensions of the trench, trench backfill media/material, and gas piping and current LFG
remedial status at the site after the trench has been install in 2010.

SECTION II - Engineering Plan
4. (Section 1.3) The facility contact is obsolete.
5. (Section 1.5.1) The remaining air space/capacity of Phase1 should be 74,800 CY.
6. (Section 1.5.8) The Sheet 7 shows the cross-section of the landfill phased development; elevations of the
seasonal high ground-water table and the bedrock datum as stated in this section are not
available. Please add the described data to the sheet.
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7. (Section 1.5.9) The temporary bench mark info is different from that shown on Sheet No. 2. Please
clarify.
8. (Section 1.6.6) The erosion and sediment control details are shown on Sheets 9 & 10. Please correct
typo.

Attachment II-B, Technical Specifications
9. (Section 02292-, Infiltration Barrier Layer)
ii. (Paragraph 3.02.C) The specified compaction effort is that the in-place dry density of compacted
soil liner shall be greater than 90% of the maximum dry density defined by ASTM D 698. This
specification is acceptable only if the density of each soil sample is equal to or greater than 120
pcf as specified in the Slope Stability Analysis & Section 2.1.4 of the Closure Plan. Otherwise,
slope stability analysis must be conducted by using the soil testing results obtained from the
CQA program. A sensitivity analysis for upper- and lower-bound data ranges shall be
implemented for the slope stability analysis.
iii. (Paragraph 3.03.B) Please verify the final thickness of (24 inches ?) the compacted test pad for
compacted soil liner/infiltration layer.
iv. (Paragraph 3.03.E) Please specify the acceptable ranges for in-placed testing of moisture content
and moisture control procedures during the period of constructing the 18-inch-thick compacted
soil liner/infiltration layer.

10. (Section 13302, Geocomposite Drainage Net (GDN))
i. (Paragraph 2.01) The specified interface friction angle of 24 degree is less than that (28 degree)
specified in Section 2.1.4 of the Closure and Post-Closure Plan. Please correct the typo. If this
is the friction angle between geotextile and geonet, please state so.
ii. (Paragraph 3.0.2.F) Anchor trench for the GDN installation is not available in the submitted
drawing, please provide the anchor trench details. Additionally, should the trenching excavation
and backfill comply with Specification Section 02221 and testing requirements specified in Part
B.2 of the CQA Plan? Please clarify.
iii. (Paragraph 3.03) The specified geonet connection should be referred to Paragraph 3.02. Please
correct typo.
iv. (Paragraph 3.05) The minimum thickness of a cushion layer of soil/earthen material overlain the
GDN must be specified here to prevent the installed GDN from damage from construction of the
specified compacted soil liner which is constructed on top of the GDN.

11. (Section 13320, Landfill Gas Vents)
i. Paragraph 2.01 should specify the dimensions of the gas vent trench as shown Sheet No.
8. Additionally, to avoid the waste being exposed to daylight while in trenching, the maximum
length of trench should be constructed must be specified.
ii. Where the geotextile specified in Paragraphs 2.02 & 3.02 will be used in the gas venting
system? The geotextile is not shown on details of gas venting system on Sheet No.8.
iii. The record of locations of buried asbestos-containing material or wastes should be documented
as stated in the Section 2.5.3 (on Page IV-7) of the Operations Report. The statement in
Paragraph 3.01. is incorrect.
iv. The vent pipe system construction sequences in in Paragraph 3.02. B are not consistent to the
details on Sheet No. 8. Is there a layer of geotextile to be place in the bottom of the trench to
separate #57 stone and waste?

SECTION III - CQA Plan
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12. (Part A.6) Should deviation of the approved CQA or Specification or design of the landfill during the
construction period occur, the County must submit the change order document or a written request of an
approval of the deviation from the SWS prior to implementing the change. Engineering judgement,
made by a licensed Professional Engineer of the State of North Carolina, on the change order in the
construction period may be considered on a case-by-case basis. These deviations must be a portion of
the certified CQA report in Part E – Final Documentation.
13. (Part B.1)
i. The ASTM D422 has been withdrawn by the subcommittee. Please provide the new testing
method.
ii. Please add the hydraulic conductivity testing specification for earthen material to be used for
constructing 18-inch-thichk infiltration layer to the table. The confined pressure and hydraulic
gradient must be specified according landfill cover condition.
iii. Please add the shear testing specification for the earthen material to be used for constructing 18-
inch-thichk infiltration layer to the table. The shear strength criteria must be consistent to those
used in the Slope Stability Analysis.
14. (Part B.2)
i. The frequency of confirming each layer thickness of the final cover system shall be consistent
with the specification of Part E.2.d (50-ft by 50-ft grid). Please correct the typos in the table.
ii. Please add the hydraulic conductivity testing specification for earthen material to be used for
constructing 18-inch-thichk infiltration layer to the table. The confined pressure and hydraulic
gradient must be specified according landfill cover condition.
15. (Part C.1.c, Conformance Testing)
i. What are conformance test items? Please specify.
ii. The interface shear strength between geocomposite and earthen material (Compacted soil liner
and intermediate soil cover) must be tested to ensure the final cover system can safely stand
according to the slope stability analysis stated in the Engineering Plan and Closure & Post-
closure Plan. Test method and frequency should be added to this section.
16. (Part C.1.e.2) Does the County propose using GCL for the landfill project? If not, please remove this
item.
17. (Part C.1.e.f) According to Sheet No. 8- Landfill Gas Vent details, there is no clamp to tight the
geocomposite to the PVC vent pipe riser, but bentonite/soil mixture plug is proposed. Please revise the
specification to consist the drawing details.
18. (Part D.3) The passive gas vent will be placed inside trench as shown on the drawing Sheet No.
8. Please revise the specification requirement to match the proposal.
19. (Part D.4) Geosynthetic liner material - geomembrane will not be used for the final cover system;
therefore, the MQA & CQA for a seam strength of the liner material are not applicable in this
project. Additionally, this part should specify the CQA requirements for compacted soil liner such
compaction effort, hydraulic conductivity, soil type etc. as specified in Part B.
20. (Part E.2.b) The licensed surveyor must be registered in the State of North Carolina, not Virginia.
21. (Part E.2.d)
i. Are there subparts E.2.d. 2) & 3) - Erosion/Vegetative Support Layer & top soil layer? Or just a
typo.
ii. At sloped areas, please note the required minimum thickness of each layer of the proposed final
cover system shall be measured perpendicularly to the slope surfaces.
22. (Part E.4) Please cite the North Carolina Law or Rule, not the ones of Virginia.

SECTION IV - Operations Report
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23. (Section 2.5.2) The C&DLF is destructing a mobile home at the landfill working face and recovering
marketable or recyclable material; therefore, please add the required operation requirements to the
section, which will be incorporated into the permit conditions.
i. Mobile homes that are defined in N.C.G.S. 130A-309.112 and generated from the approved
service area - Orange County will be accepted for deconstruction.
ii. The permittee must implement the approved plan to temporarily store mobile homes, stockpile
recyclable materials, and conduct deconstruction activities. The storage and deconstruction
activities shall take place only near the working face of the C&DLF – Phase 1.
iii. Regulated-asbestos containing material as defined in 40 CFR 61 must be managed in accordance
with 40 CFR 61. The permittee must follow the operations plan to properly remove asbestos-
containing material from a mobile home. Disposal of asbestos waste must be in accordance with
Rule 15 NCAC 13B .0542(c)(2) and the operations plan.
iv. White goods, as defined in N.C.G.S. 130A-290(a)(44), which are within mobile homes to be
deconstructed, must be properly removed to the White Goods and Scrap Metal Area prior to
deconstruction activities. White goods must be managed in accordance with all federal, state,
and local applicable statutes and rules and the Permit Conditions in Permit No. 6801-MSWLF-
1993 (DIN 19609).
v. All mobile homes must be deconstructed within 45 days from acceptance into the deconstruction
area. The date of receipt at the landfill shall be posted on the mobile home or its frame.
vi. All material not planned for recycling must be placed in an approved disposal unit before the end
of the day in which deconstruction takes place. Recyclable materials may be stockpiled at the
designated location as shown on Drawing No. 2 for no more than 45 days from the date of
deconstruction.
vii. Records shall be kept at the facility.
24. (Section 2.5.3)
i. The referenced statute of the solid wastes prohibited from disposal in landfills shall be N.C.G.S.
130A-309.10(f) and Rule 15A NCAC 13B. 542(e). Please correct the typo. Additionally, please
add waste stated below to the prohibited waste list. Used oil; antifreeze (ethylene glycol);
aluminum cans; whole scrap tires, as provided in N.C.G.S. 130A-309.58(b); lead-acid batteries,
as provided in N.C.G.S. 130A-309.70; motor vehicle oil filters; recyclable rigid plastic
containers; wooden pallets, except that wooden pallets may be disposed of in a landfill that is
permitted to only accept construction and demolition debris; oyster shells; discarded computer
equipment, as defined in N.C.G.S. 130A-309.131; and discarded televisions, as defined in
N.C.G.S. 130A-309.131.
ii. The designated disposal area for asbestos-containing material or waste (ACM) is not shown on
drawing Sheet No. 3. Please add the disposal location(s) to the drawing.
25. (Section 2.14) Please add the rule-required operation procedures to remove wind-blown trash at the
conclusion of each operation day to this section according to Rule 15A NCAC 13B .0542(g)(3).
26. (Section 2.15) The working face of the C&DLF will be covered at least weekly as described in Section
2.11.1. The daily cover of wastes is proposed in this section is contradicting that stated in Section
2.11.1. Please clarify.
27. (Section 2.20 & Section 4.2 of the Contingency Planning) The fire report and the report of attempt of
illegal disposal of nonconformance or prohibited wastes (Section 2.5.3) shall be placed in the operating
record at the landfill facility.
28. (Section 3.2) The C&DLF should monitor the concentration of hydrogen sulfide concentration in the gas
probes and buildings/closed structures at a quarterly basis. The threshold limit for remedial action of
hydrogen sulfide and monitoring protocols must be described in this section as well.
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29. (Section 4.2 & Attachment IV-C) The SWS has the standard form to report of a fire at a solid waste
management facility. If the County intends to use please download the fire occurrence report at the
following web link and append to the Operations Plan.
https://files.nc.gov/ncdeq/Waste%20Management/DWM/SW/Forms/FireOccurrenceReport.pdf
30. (Attachment IV-C, Section 5.5) The person to be contacted for an emergency at the facility must be
updated.
31. There are two temporary disaster debris sites – C&D waste/ DS68-002 and vegetative waste/DS68-001
at the C&DLF Phases 2&3 area. Please describe the site operations after a nature disaster declamation
was made of the State Governor. The descriptions of operations for each unit may include, but not
limited to, the time to start and terminate operating waste activities (6 months), permitted waste
streams at each unit, acreages of each unit, the maximum volume/capacity of each unit (dimensions of
stockpiles), waste operations – storage, separation, treatment, processes, recycling, and/or disposal. The
info will be incorporated into the permit.

SECTION V - Closure and Post-Closure Plan
32. Please use NCDEQ instead of DENR throughout this plan.
33. (Section 2.1.3)
i. According to the Drawing No. 8 of the typical details of the final cover system, a minimum of
12-inch-thick intermediate/weekly cover will be one of the component of the proposed final
cover system; but the Section 2.1.3 (under sub-section 1. Plan Sheets) proposes that “top soil
stripped from intermediate cover will be stockpiled for use during final closure.” This statement
may create some level of confusion that County may remove the intermediate soil cover prior to
installing the final cover system. Please clarify the intention of this proposal in this section.
ii. Please add a typical detail of the described diversion berms on the drawing. By the way, is the
symbol DD on Drawing No. 6 referring the diversion berm?
iii. Add the minimum thickness of the intermediate/weekly cover to this Section.
34. (Section 2.1.6)
i. The SWS record shows the LFG trench was completely constructed in February 2010. This Section
or Section 3.2 of the Operations Report of the application should describe the as-built conditions of
the trench and venting system and the status of gas migration results from the completion of this
intercept trench. The Drawing No. 8 doesn’t contain any gas interception trench details. Please
provide the current condition of the system, not the proposed one.
ii. A layer of geocomposite material will be placed between the gas trench/intermediate cover and
compacted soil liner as shown on Figure 8. The section must describe the material and construction
specifications (Section 13302?) of this geocomposite material. According to the specification –
Section 13320, it is likely a layer of geotextile will be placed inside the bottom of the gas trench to
separate waste and backfill aggregate. If this is correct, please revise the section accordingly.
35. (Section 2.3) The remaining air space/capacity of Phase1 should be 74,800 CY.
36. (Section 3.1) The person for the facility point-of-contact contacted must be updated.
37. (Section 3.3 & Attachment V-1) Should the surface water quality in the adjacent surface water-body be
a part of water quality monitoring program. Additionally, the inspection and maintenance of the
sediment basin(s) associated with this landfill must be routinely inspected and maintained to avoid
siltation. This program is not available in the Post-Closure Plan.
38. (Sections 3.3.1 & 3.3.2 & Attachment V-1) For any gas or groundwater monitoring wells, the inspection
and O&M programs in the post-closure care period should include, but not limited to, the inspection of a
well casing lock, identification tag or placard containing well data, and/or a concrete pad including
bollards to protect the well casing, if installed. Please include theses inspection items to the Section
3.3.1 & 3.3.2.
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39. (Section 3.4.2 & & Attachment V-1) The access roads/paths to the monitoring locations must be of all-
weather construction and maintained in good condition. Please add this requirement to this Section.
40. (Section 3.4.6) The SWS file system doesn’t contain “The Landfill Gas Remediation Plan” prepared by
DAA, dated December 16, 2009. Please append a copy of this document to the Closure and Post-
Closure Plan.
41. (Sections 3.4.5 or 3.5) Please describe the inspection and repair of leachate outbreak at the side slopes of
the final cover system, which are listed in the inspection checklist (& Attachment V-1).
42. (Section 4.3) Per NCGS 130A-295.2(h1), the County shall provide a financial assurance (FA) at least
one million dollars in costs for potential assessment and corrective action (PACA) at the facility. This
PACA FA is subjected to annual adjustment of for inflation since FY-2009 and is additional FA to the
costs covering the ongoing corrective action programs at this landfill facility.
43. (Attachment V-2) Please revise the closure cost estimate accordingly.
i. The Cost Item XII should include the costs for proposed diversion berms, slope drains, and outlet
energy dissipaters/stabilizer (riprap), Culverts 4A through 4C, & storm drains toward the
Sediment Basin.
ii. The Cost Item XIII associated with landfill gas vent system:
a. Provide the prices and quantities for 6-inch-diameter PVC piping, #57 stones, 6oz/square
yard geotextile, installation, etc.
b. Cost of linear footage of trenching excavation and backfill per vent.
c. According to Drawing No. 6, there are 11 gas vents will be installed over 7.7-acre closed cap,
not 8 vents. Please revise the cost estimate.
44. (Attachment V-2) Please revise the post-closure cost estimate accordingly.
i. Please add the cost for surface water monitoring.
ii. Cost Item I – Groundwater Monitoring. There are 8 wells shown on Drawing No. 2. Please
explain why 5 wells are considered in the estimate.
iii. Cost Item II. Should the costs associated with maintain/repair gas vent system in the constructed
gas intercept trench be considered in the post-closure period?
iv. Cost Item IV. Should the cost for repairing leachate outbreak area be considered?
v. The costs associated with repairing road for all-weather condition, security control devices.
45. (Attachment V-4)
i. Please provide the reference(s) for the veneer/infinite slope analysis used in the project.
ii. The input data for global slope stability analysis shows the side slope of the final cover system is
approximately 25.6 degree measured from horizontal surface, not the proposed side slope 2.8
degree or (3.5 to 1 slope) as stated in Section 2.1.4 of the Closure and Post-Closure Plan.
iii. The geocomposite material will be displayed over the final cover system, the veneer/infinite
slope analysis should be conducted to confirm the specified interface angle of 28 degree (as
shown on Table in Section 2.14), between the layer of geocomposite and the overlain compacted
soil liner and underlain intermediate material is safely standing during the 30-yr post-closure
period and beyond.

Please contact myself if you need further clarification on the above-mentioned comments. Have a wonderful
evening.

Ming-Tai, Chao
Environmental Engineer, Solid Waste Section
Division of Waste Management
North Carolina Department of Environmental Quality
919.707-8251 (Office)
[e-mail]
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From: Chao, Ming-tai
Sent: Wednesday, January 09, 2019 1:04 PM
To: 'Gordon Dively' <[e-mail]>
Cc: Bruce Woody <[e-mail]>; Tyrus Clayton <[e-mail]>
Subject: RE: [External] Orange County Permit Renewal

Dear Mr. Dively:

Thank you and Bruce for promptly resending the permit applications for Orange County Landfill units. The
received documents are uploaded to Division file system – Laserfiche this noon with unique file document
identification number (FID):

FID 1274688 - Permit application for post-closure land use, Operations Plan for no-disposal waste management
units at the closed MSWLF, permit # 6801-MSWLF-1993.

FID 1274690 – Permit amendment application (Life-of-site) for continued operating Phase 1 of the CDLF,
permit # 6804-CDLF-2005.

I will work on the CDLF permit application first then deal with the closure permit for 68-01 including post-
closure land use permit for all the closed lined and unlined landfill units – including CDLF, MSWLF & all non-
disposal waste management units later. Please contact me if you have any questions of the permitting process,
thank you and have a wonderful day.

From: Gordon Dively <[e-mail]>
Sent: Wednesday, January 09, 2019 9:59 AM
To: Chao, Ming-tai <[e-mail]>
Cc: Bruce Woody <[e-mail]>; Tyrus Clayton <[e-mail]>
Subject: [External] Orange County Permit Renewal

CAUTION: External email. Do not click links or open attachments unless you verified. Send all suspicious email as an attachment to
[e-mail]

Ming-Tai, Chao
Environmental Engineer, Solid Waste Section
Division of Waste Management
North Carolina Department of Environmental Quality
919.707-8251 (Office)
[e-mail]
8
Ming,

Included below are links to the requested documents for Orange County. Please let me know if you have any issues
downloading the two.

Here is the link to the Operations Plan for the Closed Landfill, Permit Number 68-01 (DAA PN R00592-00):

https://files.daa.com/dl/1iZgURzw3d

Here’s the link for the active C&D Landfill, Permit Number 68-04 (DAA PN R00592-179N):

https://files.daa.com/dl/FIrbmurZf0

Thank you,

Gordon Dively, PE
Senior Engineer

Draper Aden Associates
Engineering • Surveying • Environmental Services
Lasting Positive Impact™

Office: 919.827.0864 • Mobile: [phone]

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