2017-02-03_PERMIT FILE - C1980004 ‎(26)‎

• Permit No: C1980004
• IBM Index Class Name: Permit File
• Doc Date: 2/3/2017
• Section_Exhibit Name: Appendix U Construction Quality Assurance Plan
• Media Type: D
• Archive: No

APPENDIX U
on the same soils subjected to different specified compaction energies. The line of
optimums is essentially parallel to the zero air voids curve (100% saturation), and
typically corresponds to a soil saturation of about 85%. An adequate QA/QC
requirement to ensure that a compacted low permeability soil liner will achieve a
hydraulic conductivity of less than or equal to 1.0 x 10.7 cm/sec should state that at least
80% of field measured moisture content/dry density points fall on or above the line of
optimums. See Reference number 4 below for supplemental information.
Soil Drainage Layer - QA/QC design requirements for soil drainage materials used in
the cell leachate collection system (LCS) should ensure suitability of drainage material,
proper placement and compaction (as applicable) and subsequent protection. Consistent
with WCF recommendations, the CQA testing program should emphasize grain -size
distribution analyses rather than hydraulic conductivity testing, with particular attention
paid to the amount of fines present in the drainage material.
Accordingly, a demonstration should be made in terms of grain size distribution analyses,
that the range of the soil drainage material source can achieve the minimum required
permeability. The design requirements should be written in terms of the grain -size
distribution analyses that correlate with attainment of the minimum required
permeability, as based on the results of a successful demonstration.
The Soil Drainage Layers CQA grain size and hydraulic conductivity test frequencies in
the following QA/QC TESTING TABLE are based on incorporation of a grain -size
distribution specification(s) that correlates with attainment of the minimum required
permeability. The Division strongly recommends that the hydraulic conductivity testing
frequency should be increased to compensate for elimination of the grain -size distribution
specification(s).
Synthetic LCS Materials - Suitable synthetic drainage materials may be proposed.
However, select trash should not be used for LCS drainage material.
In order to minimize bio fouling, geotextile is not recommended as a filter wrap around
collector piping or around gravel bedding used as a collector. However, it is believed
that the greater surface area available from a geotextile blanket that overlies a drainage
layer allows leachate flow prior to entering the collector pipe. The fabric may clog
directly over the collector but continue to permit flow within a few feet of the collector
and between collectors.3
Protective Layer — The integrity of LCS's should not be compromised by the intrusion
of fine grained soils, overlying wastes or other contaminants or by penetration of heavy
objects. Engineered protective layers (including appropriate soil filters and geotextiles)
and supervised placement of innocuous "select trash" over leachate collection systems
are examples where QA/QC measures may be employed to reduce potential adverse
effects on the LCS's ability to transmit flow. Another advantage of employing
engineered soil protective layers is to aid in mitigating potential adverse effects of
desiccation and freeze/thaw cycles on an underlying soil liner's hydraulic conductivity.
Additionally, engineered soil protective layers and geotextiles may be used to aid in
mitigating potential degradation of geomembranes from ultra violet light.
PR -02 10/12