8202_SampsonCoMSWLF_20170516_Cell10ConstructionMeetingNotes_DIN27734

MEMORANDUM

Date: May 16, 2017
To: Distribution and Meeting Attendees
From: John R. Fearrington, E.I.
Smith Gardner, Inc.
RE: Construction Progress Meeting No. 2 Summary
Sampson County MSW Landfill – Cell 10 Construction

Meeting Summary:

Progress Meeting No. 2 was held Tuesday, March 28, 2017 at 11:00 am at Waste Industries’
Sampson County Landfill Office to discuss Cell 10 construction progress for the Sampson
County Municipal Solid Waste (MSW) Landfill Permit Area 82-02. A walkthrough occurred
directly following this meeting. The following represents notes from the items discussed:

1. Attendance:

See attached attendees list.

2. Schedule:

Current Progress
• Piezometers 10C through 10J have met or exceeded design elevations;
− West slope no longer demonstrating seepage;
− PZ 10A, and 10B water levels are slightly higher than acceptable;
• Test pits have been excavated in the area of PZ-10A to evaluate the extent of
water levels in this area. It was determined that a small area of perched
water is affecting the water levels around these piezometers; and
• Overexcavation and backfill in progress along the southeast corner of cell 11.

Planned Activities
• Continue to monitor PZ-10A and 10B;
• Determine best plan of action to achieve required separation between
groundwater and subgrade;
• Remove unsuitable materials from the southeast corner of Cell 10;
• Remove existing access road within Cell 10;
• Move forward with conformance testing of CCL and structural fill materials;
and
Construction Progress Meeting No. 2 Summary
May 16, 2017
Page 2 of 2

H:\Projects\Sampson County Disposal\Sampson-17-1 (Cell 10 Construction)\Construction\02 Meetings\2017-3-28__Progress
Meeting No. 2\2017-3-28__SCD Cell 10 Mtg Summary.docx
• Construct CCL test pad/pads within the footprint of cell 10 once the permit to
construct has been received. A soil liner construction meeting was held after
the conclusion of this meeting and a summary is attached.

3. Submittals:
• Geosynthetics testing is in progress for drainage geocomposite and
geomembrane. Bentley and S+G to provide clay and protective cover material
for interface testing; and
• S+G will look to submit CQA data to NC DEQ for preliminary review before
completion of Cell 10. Preliminary review will include in-place and laboratory
testing of soils and laboratory testing of geosynthetics.

4. Other items:
• Cell 10 GGI
− Piezometers PZ-10C through PZ-10J have met their goals for
subgrade separation; PZ-10A and PZ-10B have not met their goals.
− A design modification was submitted to NC DEQ on March 10, 2017 that
addressed installation of an additional GGI trench west of the existing
GGI system. This modification was approved by NCDEQ.
• Clay material has been found in the North 300 area of the Canal Property and
some permeabilities pass required specifications. Bentley will create a test
pad to try blending different materials to meet required specifications.
Bentley estimates 15,000 CY of clay has been located;
• Bentley and Sampson will coordinate transition to new Cell 9 access ramp;
and
• After this progress meeting a soil liner meeting was held to discuss
requirements of the compacted clay liner. A summary of this meeting is
attached.

5. Action Items
• S+G will provide an engineering method to drain perched areas within Cell 10
and continue to evaluate the potentiometric surface;
• Once perched areas are drained S+G will submit a revised grading plan for
subgrade of Cell 10 that will meet groundwater separation requirements.

6. Next Meeting

The next project progress meeting is scheduled for Tuesday, April 25, 2017 at 11:00 am.

Attachment: Attendee List
Soil Liner Meeting

cc: Attendee List
File
SMITH GARDNER, INC. Soil Liner Meeting Agenda
Sampson County Disposal, LLC – Cell 10 Page 1
SOIL LINER MEETING
AGENDA

1. Review of Specification Requirements (Tech. Specification Section 02250)

Test Fill Construction:
• Tentative location/Timeframe
• Record survey of test fill subgrade (if in cell)
• Size: 20' x 50' Min.
• Depth: 4 - 6" compacted lifts
• Same materials and equipment to be used in main construction

Construction of Compacted Soil Liner (CSL):
• Confirmation of test fill must be complete before beginning
• Subgrade preparation and proof-roll
• Loose CSL placed in max. thickness of compaction feet (or penetration depth)
(first lift placed thicker to avoid subgrade contamination - o.k.)
• Clod size: < 3/4 inches (may require breakdown prior to compaction)
• Compaction Requirements: > 95% Std. Proctor; > optimum moisture
content; k < 1 x 10-7 cm/sec; 24" min. finished thickness (0.15 foot overbuild
allowed)
• Protection of CSL from rain and desiccation (i.e. overbuild and smooth drum
roll)
• Scarify surface prior to placement of subsequent lifts or prior to moisture
addition if material is determined to be too dry
• Holes in CSL - patch with compacted CSL or sodium bentonite compacted
and hydrated
• Surveying: Verify thickness and slope of CSL using survey grid (from
surveyor)

2. Review of CQA Requirements (CQA Manual Section 4.0)

Performance of Control Tests on CSL material (Testing Underway)

Approval of CSL subgrade (visual and review of survey information)

CQA Testing:
• CQA testing in accordance with CQA Manual
• Timeframe for turnaround of CQA tests (typ. 2 to 3 days for preliminary
hydraulic conductivity test results)