7607_GreatOakMSWLF_Comment_CQArpt_Phases1_Cell2_DIN28825_2018003

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Chao, Ming-tai
From:Chao, Ming-tai
Sent:Friday, August 03, 2018 9:41 AM
To:'Lamb, Steve'
Cc:Harrison, Susan; Patrone, John; Stanley, Sherri; Ritter, Christine; 'Moore, Daniel'
Subject:Comments on CQA Rpt - Great Oak MSWLF, Phase 1-Cell 2
Hi Steve:

DIN 28825
Below are comments on the CQA Report (DIN 28824):

1. (Section 4.5, Table -2) The number of samples that was sent to lab for destructive seam testing is 47 (not
49) including the two re-test samples DS-4A1 & DS-4B1.

2. (Section 4.6, Appendix C, Appendix H-2, & As-built Drawing) According to the Leak Location Test
Report, three (3) areas in the primary liner layer were confirmed to be leaks and excavated for
repair. The leak areas/locations should be shown on the as-built drawing in Appendix C-5; the areas
which have been repaired and retested should be documented in the repair log and test log accordingly
of the primary geomembrane liner.

3. (Sections 7.1 & 7.2 & Appendix F) Please provide additional info, data, or testing results:
i. The approved CQA Plan in the 2017 Project Manual (DIN 28504) and construction drawings
(revised 10/19/2017) specify the non-woven geotextile (GT) in the LCR & LDS piping trenches
with a mass per unit area of 8 oz/yd2. According to Sections 7.1 & 7.2, 10 oz/yd2 non-woven GT
was used for cell 2 construction; Engineer certification / approval this material deviation from
the specification is required.
ii. The MQA testing data (referring to Tables 0519.13A & 0519.13B) of the 10 oz/yd2 GT should be
placed in the CQA report according to Specification 31 0519.13.
iii. The MQA testing data for the piping for LCR, LDS & force-main (referring to Tables 0533-A)
should be placed in the CQA report.
iv. The QA/QC testing data results of Type S-1 backfill material inside the piping trenches of LCR,
LDS & force-main should be placed in the CQA report (referring to Specifications 31 2316.13 &
31 2323.13 & Table 3-1 of the CQA Plan.
v. The approved construction drawings allowed #5 drainage aggregate used in the LCR & LDS
piping trenches, but the #57 stone was specified in the Technical Specification 31
0519.16. Clarification/approval of using new drainage aggregate for Cell 2 in this section is
required.

4. (Section 7.4) The as-built drawing illustrating the force-main is likely on Drawing 2 of 2 in Appendix J.

Appendix C4 – Secondary Geomembrane Liner
5. (Geomembrane Panel Deployment Log dated 03/10/2018) Please verify and confirm the deployment
length of panel S-19. The log shows the panel length is 9 feet long, but the drawing shows the panel
length which is far more than 9 feet.

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6. (Geomembrane Seam Log dated 3/20/12) The data of panels 24 & 25 is not available.

7. (Geomembrane Repair Vacuum Test Log) In the following areas test data is not available in the test log,
but the data is listed in the Repair Log (Defect Log): 1Q (S13/S17/S20), 1H (S12/S13/S17), & 15F
(S201/S202).

Appendix C4 – Primary Geomembrane Liner
8. The seam connecting Panel 53 and Panel 57 (as shown the As-built Drawing) is not available in the
Seam Log, and the seam testing data (either pressure or vacuum testing) is not available.

9. (Geomembrane Seam Log )The following data are not available in log:
i. Panes of primary liner seamed with the underneath secondary lines – P24, 25, 26, 27, 108, 159,
160, 161, 162, 164, 165, 167, 168, 169, 170, 171, 172, 173 & 176.
ii. Panel 53 and panel 57.

10. (Geomembrane Seam Pressure Test Log) The testing data on seam connecting panel 53 and panel 57 is
not available.

11. (Geomembrane Defect Log, Sheet No. 3)
i. The defect location (Defect Code 3V) at the panel corner intersection of Panels 1, 32, & 33 is
likely a typo.
ii. The following panel corner intersections of panels are not available in the Defect Log, Repair
Log & Vacuum Test Log: intersection points of Panels 68/69/41 & Panels 153/154/170,
respectively.

12. (Geomembrane Repair Vacuum Test Log)
i. The following areas under the Defect Codes described in the Geomembrane Defect Log are not
available in the Vacuum Test Log: 3C & 3I.
ii. The testing data on seams connecting primary liner panels P57 & P58 to the underneath
secondary liner panels are not available.

Appendix J
13. (Drawing No. 02 of 02) Please address the following concerns:
i. The following survey point is likely placed in the wrong location or the contours may need to
adjust accordingly:
Survey Point No. Elev. at the top of protection
cover (ft)
The location at the contour in
Drawing No. 2 of 2
1347 631.14 629
4354 583.84 586

ii. On the as-built drawing, please provide the invert elevations of the riser pipes – both LCR and
LDS according to October 09, 2017 Response to Comment No 8. (DIN 28530).

Please send in an electronic copy of the responses to the comments and contact me if you have any questions of
the comments. Have a wonderful weekend.

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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