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
Background and Discussion: Consistent with the Division's Solid Waste Guidance Document
Concerning Solid Waste Site and Facility Engineering Design/As-built Documents (dated
April 16, 2008), written QA/QC plans must be developed and implemented for all
engineered waste containment facility structures with the exception of ancillary
components (e.g., entrance roads, gate houses, maintenance buildings, etc.). Where
applicable, an effort has been made to incorporate the QA/QC tests and test frequencies
found in the EPA Technical Guidance Document entitled Quality Assurance and Quality
Control for Waste Containment Facilities as well as Waste Containment Facilities 2°a
Edition (WCF) into this guidance document (see references). Updated test methods are
put forth in some cases.
Guidance: QA/QC is divided into manufacturing quality assurance (MQA)/manufacturing quality
control (MQC) and construction quality assurance (CQA)/construction quality control
(CQC). Ideally, QA (i.e., measures taken by the QA organization) should be independent
of QC (i.e., measures taken by the manufacturer, installer or contractor).
It is expected that an increased level of QA/QC may be incorporated into designs
involving materials that exhibit a relatively higher degree of inherent variability or
uncertainty. Deviations from conventional QA/QC test frequencies and ASTM methods
contained in this guidance may be justified based on supporting documentation. In any
case, suitable standard equipment that enhances effective execution of a given QA/QC
task and that is capable of meeting specified accuracies and tolerances should be
employed.
Waste containment facility disposal cell engineering design should include, but not be
limited to, QA/QC plans that include measurable requirements for the cell subgrade,
liner, leachate collection system (including sumps) and protective layer components.
Cell structures may consist of natural or manmade materials. In general, geosynthetic
clay liners (GCLs) should only be used as a component of a composite liner (e.g., in
conjunction with natural low permeability soils or geomembranes).
Survey Requirements - Survey methodology and/or other pertinent measurement
procedures should be incorporated in the QA/QC plan to verify the applicable criteria and
specifications put forth in the design documentation. Horizontal and vertical survey
accuracies (i.e., as opposed to construction tolerances) should be a maximum 0.1 -foot and
a maximum 0.01 -foot, respectively, and such maximum survey accuracies should be
inherent in a survey performed by a Colorado licensed Professional Land Surveyor. Less
stringent survey accuracies may be specified to identify test/sample locations.
The Division prefers that the subgrade surface, top of soil liner, top of soil drainage layer
and top of protective layer (as applicable) vertical elevations be surveyed at coincident
horizontal coordinate points (i.e., at "stacked" points located vertically above the
corresponding subgrade horizontal survey coordinate point locations) to facilitate layer
thickness determinations at a maximum 50 -foot grid spacing and at maximum 50 -foot
intervals along grade break lines (e.g., at top and toe of side slopes) and along leachate
collector drain lines. If survey measurement locations are not stacked, the facility should
interpolate from other suitable survey measurement locations (e.g., using Trigonometric
PR -02 10/12