All facilities shall meet the following standards:
(a) Surveyed corners: All site boundary corners shall be surveyed and marked with permanent survey caps.
(b) Access roads: Facility access roads shall be constructed to enable use under inclement weather conditions.
(c) Buffer zones: All facilities shall be designed and constructed with a buffer zone that is a minimum of twenty (20) feet wide within the facility perimeter fence.
(d) Cover Material Availability: Facilities shall be designed and constructed to ensure that sufficient cover material is available to properly operate the facility through the closure period;
(e) Surface water structures: Surface water structures shall be designed and constructed to: - (i) prevent flow onto the active portion of the landfill during the peak discharge from a 25-year storm;
- (ii) Collect and control run-off from the active portion of the landfill from at least the water volume resulting from a 24-hour, 25 year storm;
- (iii) Sediment control structures shall be designed and constructed in accordance with Chapter 11 of the Water Quality Division Rules and Regulations.
(f) Performance based design: New units and lateral expansions shall comply with the requirements set out in W.S. 35-11-527. The administrator may approve replacement of the two (2) foot layer of compacted soil in a composite liner with an alternate component that performs at least as well as a two (2) foot layer of compacted soil, such as a geosynthetic clay liner (GCL).
(g) Design/construction of engineered containment system caps and liners: - (i) Compacted soil barrier layers shall be constructed in lifts which do not exceed six (6) inches in thickness, and uniform compaction of these lifts shall be assured through the use of appropriate equipment.
- (ii) All engineered containment system components shall be supported by material of sufficient bearing strength to prevent subsidence and failure of any component. This bearing strength shall be documented through materials testing as approved by the Administrator.
- (iii) Synthetic membranes used as part of any containment system shall be of a material and thickness which is suitable for the intended use, but in no case shall be less than 0.030 inches thick (30 mils) or 60 mils thick if the membrane consists of high density polyethylene (HDPE). All synthetic membranes shall be underlain by a suitable bedding material and when used with a compacted soil component, in direct and uniform contact with the compacted soil component.
- (iv) Lateral drainage layers included in composite cap and liner system designs shall be composed of either granular material or a synthetic drain net of suitable lateral permeability to promote acceptable drainage, as approved by the Administrator. Lateral drainage layers shall be protected from soil clogging by either a synthetic filter fabric or a graded granular layer of a design approved by the Administrator.
- (v) If required by the Administrator, leak detection systems shall be designed to efficiently identify failure of the overlying barrier layer
(h) Quality assurance/quality control (QA/QC): - (i) QA/QC plans shall ensure adequate construction and testing of the containment system components, including applicable observations, inspections, tests, and measurements. Applicable standards from the American Society for Testing and Materials (ASTM) and Geosynthetic Research Institute (GRI) shall be used. As applicable, the QA/QC Plans shall address:
- (B) Compacted soil layers,
- (C) Flexible membrane liners,
- (D) Leachate collection and removal systems including the operations/protective layer,
- (E) Gas management systems,
- (F) Final cover systems, and
- (G) Other components as required by the Administrator.
- (ii) For compacted soil layers describe how moisture content will be maintained or adjusted, the technique by which lift thickness will be maintained, the manner in which lifts will be compacted, the method used to measure moisture content and density in the field during construction, and the frequency of moisture content and density testing.
- (iii) For synthetic membranes describe the method used to test 100% of all seams for leaks, the frequency of destructive testing for seam strength, the procedure to be followed for post-installation defect identification and repair, the results of testing or literature review which demonstrates the compatibility of the membrane material with the waste and/or waste leachate, and the procedures used to ensure each roll of membrane material meets the manufacturer's specifications for material properties.
- (iv) For lateral drainage layers describe the method used to ensure achievement of the approved grain size uniformity and layer thickness for granular layers, the method by which drainage layers shall be installed without damaging any imbedded leachate collection system, leak detection system or membrane, and the installation procedure for the filter fabric or granular filter layer overlying the drainage layer.
- (v) Identify key personnel, their qualifications, and their role in the development and implementation of the QA/QC Plan.
- (vi) After construction is complete the owner or operator shall submit a certification, signed by an engineer licensed to practice in Wyoming, that the approved QA/QC plan has been carried out and that the unit meets the requirements of this section. Documentation supporting the engineer's certification shall be submitted with the certification. Wastes shall not be accepted in the newly constructed unit without written authorization from the Administrator. Copies of the engineer's certification and supporting documentation shall be maintained in the operating record.
(i) Slope stability for excavations: Trench walls shall not exceed a ratio of 1.5:1 (horizontal:vertical) unless a slope stability analysis demonstrates steeper slopes can be safely constructed and maintained. This analysis may be based on site specific soil stability calculations or Wyoming Occupational Safety and Health Administration regulations for excavations.
(j) Methane control systems for on-site structures: All structures on the landfill facility will be designed to prevent the accumulation of methane such that the concentration of methane gas in facility structures does not exceed twenty-five percent (25%) of the lower explosive limit (LEL) for methane.
(k) Landfill gas management systems: If required, the permit application shall include landfill gas management system design and construction information.