7607_GreatOakMSWLF_Rquest_Cell 1_LeftOver_Drainage_Composite_forCell2_DIN28742_20180206

Environmental Consultants 2520 Whitehall Park Drive 704 504-3107 and Contractors Suite 450 FAX [phone] Charlotte, NC 28273-3557 www.scsengineers.com

Offices Nationwide
February 5, 2018
File No. 02215305.05

Mr. Ming-tai Chao, PE Division of Waste Management / Solid Waste Section
North Carolina Department of Environmental Quality
1646 Mail Service Center
Raleigh, NC 27699-1646
Subject: Notification of Using Geocomposite from Cell 1 Project for Cell 2 Project
Request for Variance with Transmissivity Testing Requirements
Great Oak Landfill, Permit No. 7607-MSWLF-2015 Randolph County, NC

Dear Mr. Chao:
On behalf of Waste Management of Carolinas, Inc., SCS Engineers, PC hereby submits this notification for using some rolls of geocomposite left over after the Cell 1 project in the current
Cell 2 project. The specifications for the geocomposite materials for Cell 1 meet or exceed the
requirements for both the Leachate Collection System geocomposite and for the Leak Detection
System geocomposite proposed for Cell 2.
Following the completion of Cell 1 at the Great Oak Landfill approximately 20 rolls of unused geocomposite (SKAPS TN-330-2-8) were stored on site. The rolls were stored on the ground in
the manufacturer’s supplied poly-plastic wrapping. During the Cell 1 project, the geocomposite
rolls were all tested (MQC and CQA) in accordance with the Technical Specifications and CQA
Plan. Results of MQC and CQA testing were included in the Construction Certification Report
for Cell 1A.
Following completion of Cell 1, a minor permit modification was prepared by SCS and approved
by DEQ. The minor modification revised the thickness and transmissivity requirements of the
Leachate Collection System geocomposite and for the Leak Detection System geocomposite. In
addition, the transmissivity testing procedure was revised in the minor permit modification and
the normal load during the transmissivity test was increased from 14,370 psf to 21,120 psf. The normal loads were obtained from the Permit Application prepared by S&ME. The 14,370 psf
represents 190 feet of MSW at a unit weight of 75 pounds/ft3 plus 1 foot of intermediate soil at a
unit weight of 120 pounds/ft3. The 21,120 psf equates to 280 feet of MSW plus 1 foot of soil.
Prior to deploying the unused rolls, each roll will be visually inspected by SCS Engineers’ CQA
monitor in accordance with the CQA Plan. In addition, two rolls will be selected and a sample collected and shipped to TRI for material testing in general accordance with the CQA Plan. The
Mr. Ming-tai Chao
February 5, 2018
Page 2
location of these rolls will be noted on the as-built drawings and addressed in the Cell 2
Construction Certification Report.
As stated above the MQC and CQA transmissivity tests conducted for Cell 1 assumed a waste
depth of 190 feet. The maximum depth of waste over any portion of Cell 2 is approximately 140 feet (10,620 psf). Because of this, additional MQC and CQA transmissivity testing at a normal
load of 21,120 psf is not proposed for these unused rolls.
SCS Engineers and Waste Management of Carolinas appreciate your assistance with this project.
If you have any questions, please call Steve Lamb at 704-504-3107 or email at
[e-mail].

Sincerely,

Albert D. Glenn, PE Steven C Lamb
Project Manager Project Director/Vice President
SCS ENGINEERS, PC SCS ENGINEERS, PC
Enclosures
cc: Susan Harrison, Waste Management of Carolinas, Inc.
John Workman, Waste Management of Carolinas, Inc.

M:\PROJECT FILES\02215305.05\Correspondence\Extra Rolls of composite.docx
1
Chao, Ming-tai
From:Lamb, Steve <[e-mail]>
Sent:Tuesday, February 06, 2018 10:43 AM
To:Chao, Ming-tai
Cc:Harrison, Susan
Subject:[External] Great Oak LF Cell 2
Attachments:Extra Rolls of composite.pdf
CAUTION: External email. Do not click links or open attachments unless verified. Send all suspicious email as an attachment to
Report Spam.

Ming:

As discussed last week, please find enclosed our letter regarding the use of some left over rolls of geocomposite from
Cell 1 for the Cell 2 project.

Steve Lamb, PE
Vice President
SCS Engineers
2520 Whitehall Park Drive, Suite 450
Charlotte, North Carolina 28273
Office – 704.504.3107
Direct - 704-916-1529
Mobile – 704.576.4731