2022-02-09_PERMIT FILE - M2021046 (4)

Home Browse Search

aJ�* foster wheeler Zephyr Gold USA Ltd. PAGE 13 OF 15 Dawson Gold Project SEC. NO.: Dawson Filtered Tailings Storage Facility SPECIFICATION 02200.0 Pre-feasibility Study TECHNICAL SPECIFICATIONS FOR DATE: (ORIGINAL) Fremont County, Colorado EARTHWORKS 20-October-16 PROJECT NO.: 74201633 REVISION: A DATE: 20-Oct-16 Compact by rolling with approved compaction equipment of adequate weight and size to achieve the specified degree of compaction. The placement moisture content for Structural Fill material shall be plus or minus 2 percentage points from the optimum moisture content (ASTM D698). Structural Fill material shall be compacted to 95 percent of the maximum standard Proctor(ASTM D698) dry density. 4.5.5 GEOMEMBRANE CUSHION MATERIAL The following placement procedures apply to Geomembrane Cushion Material as classified by the criteria in Article 3.4: The moisture content of Geomembrane Cushion Material shall be distributed uniformly throughout each layer of material prior to and during compaction. The Geomembrane Cushion Material surface shall be prepared to provide an adequate surface for placement of the geomembrane. This preparation should be performed as follows: • CONTRACTOR shall place and compact Geomembrane Cushion Material in loose lifts such that the compacted thickness is a maximum of 12 in. • The minimum number of passes shall be determined by the MANAGER and ENGINEER based on observations. • The CONTRACTOR shall inspect the face after completion of the compaction, and shall clean the surface by hand or other authorized means, in order to eliminate all protruding particles with a size over'/2 inch. • If needed, the CONTRACTOR shall repeat the manual cleaning until the surface is accepted by the MANAGER or ENGINEER for geomembrane installation. • It will be the CONTRACTOR'S responsibility to maintain the approved surface in good condition for geomembrane installation. Any damage to the approved surface shall be repaired by the CONTRACTOR. Immediately prior to periods of shutdown of Geomembrane Cushion Material placement operations, including periods when rain is forecast, the exposed surface of the Geomembrane Cushion Material shall be rolled with two static passes by a 10-ton, smooth drum, vibratory roller. 4.5.6 UNDERDRAIN MATERIAL The following placement procedures apply to Underdrain Material as classified by the criteria in Article 3.5: S:\ZEPHYR MINERALS\DRMS MINE APPLICATION\02200-EARTHWORKS.DOCX