3901_Granville_ClosureReviewLetter_DIN28387_20170810

State of North Carolina | Environmental Quality | Waste Management
1646 Mail Service Center | 217 West Jones Street | Raleigh, NC 27699-1646
919 707 8200 T
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
MICHAEL SCOTT
Director
August 10, 2017
Amy Davis
Joyce Engineering
9731-F Southern Pine Blvd
Charlotte, NC 28273
Re: Closure Plan
Oxford Landfill
Granville County, North Carolina
Permit No. 39-01
Document Identification Number (DIN 28387)
Dear Ms. Davis;
The Solid Waste Section (SWS) has completed are review of Closure Plan revised April 2017 (DIN 28386)
for the above referenced permit and the following issues need to be addressed;
1.Cap System #1 (page 1) – What is the source material for the low-permeability infiltration layer? How
will the permeability requirements be achieved? What testing will performed to ensure permeability
has been met? A Construction Quality Assurance Plan is necessary.
2.Cap System #2 (page 1) – A demonstration of the alternative cap system will need to be provided to
show the alternative cap system will achieve a reduction infiltration equivalent to or greater than the
“Standard” Cap System #1.
3.Cap System #2 (for areas with slopes less than 8 percent) (page 1) – A drainage layer may be necessary,
refer to item 2. Provided technical specification of the geosynthetic clay liner (GCL).
4.Cap System #2 (for areas with slopes greater than 8 percent) (page 1) – A low permeability layer is
required. This system does not meet the minimum cap requirements.
5.Post-Closure Maintenance (page 4) – the minimum deferred time needs to be defined.
6.Post-Closure Record Keeping (page 5) – “The Division will be notified of the location for the
documents.” This is an inadequate statement, define where the documents are located.
7.Maintenance Plan A. Correction of Leachate Outbreaks (page 6)
a.“as soon as possible” A clearly defined time needs to be indicated.
b.“The soils selected for the new cover will have the lowest permeability of the available
materials?” How is the permeability going to be identified? New cover soil permeability
needs to match or exceed the permeability of an approved cap.
c.“depths exceeding the minimum required 12,” New cover soil depths need to match or
exceed the depth of an approved cap.
8.Closure/Post Closure Verification – A quality assurance plan will need to be implemented and
followed.
9.Drawing CP-01 FINAL COVER TIE – IN DETAIL – Post-settlement surface slopes shall be a
minimum of five percent and a maximum of 25 percent.
Ms. Amy Davis, PE
August 4, 2017
Page 2 of 2

10. Drawing CP-01 CAP SYSTEM #2 DETAIL (GCL OPTION) Side Slopes ≥ 8% - A low permeability
layer is required. This system does not meet the minimum cap requirements.
11. Drawing CP-01 DIVERSION BERM DETAIL ON SLOPE – Post-settlement surface slopes shall be a
minimum of five percent and a maximum of 25 percent.
12. Drawing CP-01 GCL ANCHOR TRENCH DETAIL – Post-settlement surface slopes shall be a
minimum of five percent and a maximum of 25 percent.
Please address the issues presented in this letter and submit a revised Closure Plan. If you should have any
question regarding this matter you may contact me at [phone] or by email at
[e-mail].

Sincerely,

Ethan J. Caldwell, P.E., P.G,
Permitting Engineer

cc:
Wesley Wheless, Granville County
Jason Falls, Granville County
Mousa Maimoun, Joyce Engineering
Ed Mussler, P.E, NCDEQ DWM Permitting Branch Supervisor
Jason Watkins, NCDEQ DWM
Mary Whaley, NCDEQ DWM
Jackie Drummond, NCDEQ DWM