3420_OmnisourceILF_commentsonC&PCPlans_DIN28816_20180709

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Chao, Ming-tai
From:Chao, Ming-tai
Sent:Monday, July 09, 2018 3:23 PM
To:Winegar, James
Cc:Van Burbach; 'Amy Davis'; Stanley, Sherri; Ritter, Christine
Subject:Comments on the Closure & Post-Closure Plans, OminSource ILF, 34-20, DIN 28816
Dear M. Winegar:

DIN 28816

Per info stated in the e-mail message dated June 28, 2018, the Solid Waste Section (SWS) determines the
mining operations at the landfill, a portion of the Permit to Operate Renewal Application (Application, DIN
28517) are no longer subject to reviewed because the mining operation was terminated. Instead, the SWS
conducts a review of the Appendices II through V associated with the landfill closure and post-closure activities
in Application. Below are the comments on the Application, please provide additional info and/or properly
address the concerns.
Appendix II – Closure/Post Closure Plan
1. (Section 2.1) The first sentence of the Section states “Two final cover designs are proposed.” But there
is only one cover system providing in the Section and Drawing No. CP-03. Please clarify.

2. (Section 2.2) Please provide the specified drawings to illustrate the layout and details of BMPs of the
storm water management system. (For example, Drawing Nos. CP-02 and CP-03?)

3. (Sections 3.2.1 & 3.2.2) The paths toward monitoring network should be of all-weather construction and
maintained in good condition. Please add this requirements to the Post-Closure Plan including the
inspection checklist and form and the cost estimates.

4. The landfill waste footprint must be surveyed and established by edge markers which shall be
inspected. The requirements must be added to the Post-Closure Plan including the inspection checklist
and form.

5. (Drawing No. CP-04 & Slope Stability Analysis) What is the side slope angle for the final cover
system? A 3 to 1 side slope and a 3.5 to 1 side slope are shown on Drawing No. CP-04. But the
designed slope 3.5 to 1 is used in slope stability analyses – global and infinite slope analyses in
Appendix IV. If the 3 to 1 slope is selected for the final cover system, please conduct slope stability
analyses to demonstrate that designed slope has an acceptable factor of safety.

Appendix III - CQA Plan
6. The CQA Plan refers all detail material and construction specification and required testing to the
Technical Specifications; therefore, please provide the Solid Waste Section a copy of the Technical
Specifications for each component associated final cover system for a review and approval. Technical
Specifications for the final cover system should include, but not limited to, earthen materials, GCL,
Geocomposite Drainage Material, Erosion Control Matting, HDPE Piping, Riprap, Geotextile,
Vegetation, etc.

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7. (Section 1.2.4) Please define the maximum thickness of each lift; based on the state of practice in waste
industries, the loss lift has 9-inch thickness per lift which will be adequately compacted to 6-inch
compacted lift.

8. (Section 1.4) The Solid Waste Section requests to be notified at least 10 days prior to the scheduled
preconstruction meeting which should be held at the landfill facility.

9. (Section 2.3) To ensure that minimum engineering parameters of the selected earthen material used in
final cover system equals to or exceeds those (moist density of 115 pcf and shear strength in term of
friction angle of 25 degree) in the slope stability analyses. In the CQA plan, for each parameter, the
minimum criterium, testing method (ASTM), and frequency should be specified.

10. (Section 3.0) Is there any reason that the CQA requirements for geomembrane are specified in the CQA
Plan? The final cover system described in the Closure Plan and drawings do not include geomembrane.

11. (Section 3.4.1.1) The subgrade soil layer to intimately contact geomembrane (or other geosynthetic
material) must be specified for maximum grain size of less than ½ inches or the grain size recommended
by the selected geosynthetic manufacturer. The Table 1 must provide ASTM testing method and testing
frequency of the subgrade earthen material.

12. (Section 3.4.10) This section is irrelevant to the final cover system at all. Please remove from the CQA
Plan.

13. (Section 3.6.7) A 18-inch-thick soil material is planned to be placed/installed over the geocomposite
drainage material. The Section shall provide the detail of protection measures of the geocomposite
material from being damaged by machine operations.

14. (Section 3.7) Should there any ASTM standards or GRI specifications be referenced for CQA testing
requirements?

15. (Sections 4.4 & 4.5) Both sections are likely irrelevant to the landfill closure. Please remove from the
Closure Plan.

16. The CQA plan must specify the storm water management/erosion and sediment control BMPs which are
not available.

17. The requirements for as-built survey of each components of the final cover system are not available in
the CQA Plan. Please provide the as-built survey requirements.

18. (Table 1, Sections 3) The requirement of testing of interface angle between each component of the final
cover system is not available. Please provide ASTM testing method, testing frequency, test loading and
hydraulic gradient for measuring interface angle which must be equal to or greater than the designed
value of 24.4 degree concluded in the slope stability analysis for this landfill closure project.

19. (Table 1) ASTM D 422 has been withdrawn by ASTM, please provide alternative method.

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20. (Table 1) Should the earthen material used for intermediately layer and the liner with unspecified
hydraulic conductivity be test for the internal friction angle/shear strength which shall be greater than or
equal to the assumed values used in the slope stability analyses?

21. Drawings
i. Please add the GCL and geocomposite drainage material to details in the Drawing CP-03.

ii. Show the details of tie-in, drainage conveyance measures, erosion control BMPs and/or energy
dissipator devices at the daylight/exit point of the geocomposite drainage layer or the termination
of the cap toe.

iii. Please provide stormwater draining devices/erosion and sediment control BMPs at the exit points
of the diversion berm on the south side of the landfill. The discharged stormwater must be safely
conveyed to the adjacent draining features.

iv. Should the stormwater generated from the areas on the south/southwest of the final cover be
diverted and drained to the sediment basin located in southwest corner of the landfill unit?

v. According to the Facility Audit Reports, more than one sediment basin or catch basin has been
constructed at the landfill, but not shown in the Drawing No. CP-02. Please add all proposed
sediment basins/ponds to the drawing.

vi. Three downslope pipes located on the north end of the landfill drains stormwater from a
pond/fore bay on the top of landfill to a pond at the toe of the landfill. Will these stormwater
management devices be included in the stormwater management plan for the landfill closure and
post closure activities? If the answer is positive, please add the devices to the Drawing CP-02.

Appendix IV Slope Stability Calculations
22. Please provide references and reasons to use the selected engineering properties – density (75 pcf) and
shear strength (cohesion of 500 psf and friction angle of 35 degree) for the tire fluff material in the slope
stability analyses.

23. Please provide slope stability analyses (both global and infinite/veneer analyses) for the designed 3 to 1
slopes.

24. The tiered side-slopes are shown on the Profile A-A in the Drawing CP-04. The upper portion of the
side slope has a slope approximately 3.5 to 1, and the lower portion has a slope greater than 2 to
1. Please explain why the conclusions made in the slope stability analyses included in Attachment B
based on a single uniform 3.5 to 1 slope are acceptable.

25. Determination of Static and Seismic Low Normal Load Interface Strength for the Final Cover
System: Please address the following concerns:
i. (Page 3 of 12) The last paragraph of this page indicates the ASTM D5321 will be used to determine
if the interface angles between the specified geosynthetic material and other components in the
proposed final cover system equal to or are greater than the designed one (24.4 degree). Since the
GCL is specified in the Closure Plan, the different ASTM method shall be used. Please provide the
interface friction testing method for GCL.
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ii. The 3.5 to 1 slope converts to approximately 15.9 degree, not 16.2 degree used in the
calculation. Please re-calculate the veneer slope stability analyses used the correct slope angle.

iii. Is there any reason why the soil shear strength (in term of the friction angle) being not consistently
used in the slope stability analyses – the friction angle of 25 degree is used in global stability
analysis but the slope of 27 degree used in veneer slope stability analysis.

26. The drainage geocomposite that will be daylight every 90 feet along the final slope is assumed in the
calculation of the minimum transmissivity of the geocomposite. But the slope lengths on the east and
northeast sides of the landfill are more than 90 feet. Please revise the design slope length or slope
configurations.

27. The Post-Closure Cost Estimates. The costs associate with the following cost items as stated in the post-
closure check list must be added to the cost estimate. Security Control System, Drainage and Erosion
Control System, Waste Edge Markers, paths (constructed by all-weather material) to the monitoring
network.

Please properly address the comments. If you have any questions please contact myself. Thanks.

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

E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties.

From: Amy Davis [mailto:[e-mail]]
Sent: Thursday, June 28, 2018 1:48 PM
To: Chao, Ming-tai <[e-mail]>
Cc: Winegar, James <[e-mail]>; Van Burbach <[e-mail]>
Subject: [External] RE: Unauthorized LF Closure, OminSource ILF, 34-20

CAUTION: External email. Do not click links or open attachments unless verified. Send all suspicious email as an attachment to
Report Spam.

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Mr. Chao,
This is response to your letter dated June 22, 2018. At this time OmniSource is not in the process of
landfill closure. Currently, they are placing waste from the reclamation process back into the landfill per
the closure plan elevations, they expect this process to take until around December. Below is an
approximate schedule for closure –

12/2018 – Complete placement of waste into the landfill
2/2019 – Bid project*
4/2019 – Construction of closure per approved closure plan*
10/2019 – Closure complete and final CQA report submitted*
*Please not that this schedule depends on how long it takes to get an approved closure plan. Closure plan was submitted as
part of the permit renewal in July 2015.

OmniSource requests that DEQ continues their review of the closure plan that was submitted with the
permit renewal so that they can try to meet the schedule outlined above.

Thanks,
Amy R. Davis, PE

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From: Chao, Ming-tai [mailto:[e-mail]]
Sent: Friday, June 22, 2018 10:19 AM
To: [e-mail]
Cc: Amy Davis <[e-mail]>; Mussler, Ed <[e-mail]>; Stanley, Sherri
<[e-mail]>; Heim, Susan A <[e-mail]>; Aja, Deborah <[e-mail]>
Subject: Unauthorized LF Closure, OminSource ILF, 34-20

Dear Mr. Winegar:

Please read the attached reminder letter and complete the requested tasks on or by June 29, 2018. Thanks.

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
6
Raleigh, NC 27603
Tel. [phone]
[e-mail]
http://portal.ncdenr.org/web/wm/sw

E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties.

From: Chao, Ming-tai
Sent: Thursday, June 21, 2018 9:04 AM
To: [e-mail]
Cc: Mussler, Ed <[e-mail]>; Heim, Susan A <[e-mail]>; Amy Davis
<[e-mail]>
Subject: OminSource LF

Dear Mr. Winegar:

Susan Heim, the inspector for your facility told me that OminSource LF is currently conducting
closure activities. Could you give me a call to discuss the status of the facility? Thanks.

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
NC DEQ: Solid Waste Section
portal.ncdenr.org
7
Building 217 W Jones Street Raleigh, NC 27603 Phone [phone] Mail 1646 Mail Service Center
Raleigh, NC 27699-1646

E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties.