0105_CoblesCDLF_comment_Phase3ApartialClosureCQARpt_FID 1416803_20200624

1
Chao, Ming-tai
To:Deanna Coble Martin
Cc:Kirchner, Chuck; Stanley, Sherri; Kemppinen, Hannu; Joyce, Leonard; Davis, Amy
Subject:Comment_ 0105-CDFL-1998, 2020619 Phase 3A Partial closure Report
Dear Deanna:
FID XXX
After completing a review of the June 2020 CQA report (FID 1416315) for a partial closure of the Coble’s
C&DLF, Permit No. 0105-CDLF-1998, the Solid Waste Section has several comments below. Please
respond the comments in writing and submit a final CQA report for this 5.6-acre partial closure activity and
the revised permit renewal application for Phase 1 thru 3 of the C&DLF including and the rule-required
financial assurance mechanism before July 24, 2020. If you have any problem to produce the requested
documents by the date of July 24, 2020 for a reasonable cause please contact myself for a new submittal
date within five (5) working days after receiving this message. The existing permit (DIN 25405) for
operating Coble’s C&DLF expired on September 02, 2019, and the Solid Waste Section will revoke the
permit and enforce the site closure on September 02, 2020 if the requested documents/applications are not
submitted in time for approval. This permit decision was originally sent to your attention via an e-mail
message on January 08, 2020 (FID 1387209).

1. (Sections 1 & 2.2.4) The partial closure report (DIN 24357) and the Phase 3 renewal application dated
December 2019 (FID 1378626) stated that the disposal area of 9.13 acres was partially closed, not 9.8
acres. The total acreage of partial closure areas of the C&DLF shall be 14.73 acres (= 9.13+5.6). Please
provide the correct closure acreage.

2. (Section 2.2) This Section states that “the surveyor verified the existing intermediate cover thickness to
be a minimum of 12 inches prior to Coble commencing the construction of low permeability infiltration
soil layer.” There are no survey data in Appendix 3 to confirm that the thicknesses of intermediate
cover over the 5.6-acre closure area meet the specified requirement. Please provide survey data.

3. (Section 2.2.1) According to the CQA plan (including Table 1) and Technical Specifications of the
approved Phase 3 PTC application dated March 2008 (DIN 4862), the report does not include the
following testing results:
i. Construction and QA/QC testing results associated with the test pad of the 18-inch-thick
infiltration layer [Sections 02218 & 02229 of the approved Technical Specifications (DIN
4862)].
ii. Please explain the discrepancy of number of tests described in Section 2.2.1 and those shown in
Appendices 1 & 2.
Test item Section 2.2.1 Appendices 1 & 2
K, from Shelby tube 18 18
K, from remold sample 2 1
PI NA 1
Standard Proctor NA one point method - 1
In-place density & moisture
content (nuclear gauge)
30 106 tested and 96 passed
2
In-place density & moisture
content (drive cylinder)
18 21 tested and 19 passed
iii. The Engineering Plan and Technical Specification Sections 02224 & 02227 and Table 1 (DIN
4862) require the final soil cover system pertaining a minimum friction angle of 26.6 degree by
ASTM D4767. Please provide the testing result in the CQA report.

4. (Section 2.2.2) The results of testing, per requirement listed in Table 1(DIN 4862), on the protective soil
layer/erosion layer are not available in the CQA report. Please provide the test results.

5. (Section 2.2.3)
i. The gas well diameter and the depth deviate from the approved ones (DIN 17384). Please
explain who approves the deviation and why the approval is acceptable by the Solid Waste
Section.
ii. This Section states that “for the Phase 3A closure, Coble installed six passive gas vents in a C&D
landfill, excavated pits thru the cover and infiltration layers to place perforated PVC pipes in
the top layer of the waste.” Additionally, the photos in Appendix 2 clearly show that areas for
installing gas vent were excavated after the final soil cover was completed installed. The gas
vent construction destroys the constructed soil cover; therefore, the soil testing (including, but
not limited to in-pace density & moisture content and hydraulic conductivity) on each lift per
layer must be properly conducted to demonstrate the final cover is successfully restored.

6. (Appendix 1, page 9 of 207)
i. The maximum dry density for soil sample CL-1 (Lab ID 2020-019-001-001) is 95.6 pcf. Please
correct the typo in the summary table including the % of the compaction effort.
ii. According to Table 1 (DIN 4862), the following soil testing at the frequency of one test per
10,000 CY is required, but the Lab testing results are not available in the CQA report. The
required tests are:
Particle size (ASTM D422 & D1140), soil classification (ASTM D 2487), moisture content
(ASTM D2216), PI (ASTM D4318), Standard Proctor (ASTM D698).

7. (Appendix 2, page 137 of 207) The in-place density test results at the Acre 13 (lift 1) & Acre 12 (Lift 3)
that are summarized in Field Daily Report dated 11/26/14 failed to meet the specified compaction effort
- 95% maximum dry density.

8. (Appendix 2, page 150-151)
i. The in-place density test results at the Acre 13 (lift 3) are failed to meet the specified compaction
effort - 95% maximum dry density.
ii. The density results of sample DC-1 showed on the summary table are inconsistent to those in lab
report on page 151.

9. (Appendix 3)
i. The survey points to measure the thickness of each layer of the final cover are not available on
the attached drawing sheets.
ii. The partial closure activities were not completed until March 2020 (Referring Section 2.2), but
the as-built survey was certified by the licensed survey dated October 10, 2019. Why the as-built
survey is permissible?

3

From: Chao, Ming‐tai  
Sent: Friday, June 19, 2020 2:57 PM 
To: Deanna Coble Martin <[e-mail]> 
Cc: Kirchner, Chuck <[e-mail]>; Stanley, Sherri <[e-mail]>; Kemppinen, Hannu 
<[e-mail]> 
Subject: RE: [External] 0105‐CDFL‐1998 2020619 Phase 3A Partial closure Report 

Dear Mrs. Martin:

The Solid Waste Section receives the electronic copy of the CQA report for Phase 3A partial closure; this report
is uploaded to Laserfiche with a FID 1416315. Have a wonderful day.

From: Kemppinen, Hannu <[e-mail]>  
Sent: Friday, June 19, 2020 1:25 PM 
To: Chao, Ming‐tai <[e-mail]> 
Cc: Deanna Martin ([e-mail]) <[e-mail]>; [e-mail]; Joyce, Leonard 
<[e-mail]> 
Subject: [External] 0105‐CDFL‐1998 2020619 Phase 3A Partial closure Report 

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

Ming,
On behalf Coble’s CDLF, LaBella has prepared the attached Phase 3A partial closure report for the Solid Waste
Section review. Following the partial closure certification by the Section, we will update the landfill closure and post-
closure care plans, and financial assurance. To prepare these proposed updates, we have asked Coble to prepare
the annual Solid Waste Report 2020 with annual tonnage data and updated survey. These data will be incorporated
to update the closure and post-closure care plans and the annual financial assurance in accordance with 13B
.0546.

Thank you for your assistance with the Coble’s CD landfill operations and finalizing the permit renewal process that
has been underway for quite some time. Should you have questions regarding the submitted report, we are available
to help and provide clarification.

Thank you and have a great summer weekend.

Hannu Kemppinen, PG
LaBella Associates | Senior Project Manager
4
336-790-2252 direct
336-323-0092 office
336-209-7156 mobile
2211 West Meadowview Road, Suite 101
Greensboro, NC 27407
labellapc.com [labellapc.com]