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3.2.2 Construction Procedures <br /> The vertical LFG monitoring probe casings consist of 0.75-inch diameter Schedule 40 <br /> PVC pipe. The bottom 4 (shallow probe), 5 (intermediate probe), and 10 (deep probe) <br /> feet of each respective borehole casing was perforated with 0.020-inch diameter holes. <br /> The perforated portion of the well casing of each vertical monitoring probe is surrounded <br /> by #3 sand backfill. A 5-foot thick seal layer of bentonite slurry is placed on the top of <br /> the sand backfill. Steel locking"stove-pipe"style enclosures were placed over the tops of <br /> the probe casings, and set into a concrete base. The probes were installed in general <br /> conformance with the plans and specifications. LFG probe completion details illustrating <br /> the as-constructed probes are presented in Appendix A. <br /> 3.2.3 CQA Activities <br /> EMCON observed and documented that the layout and depths of the LFG probes, casing <br /> materials, backfill materials and procedures, and probe pipe lengths were consistent with <br /> the approved construction plans and technical specifications. EMCON observed and <br /> documented the materials encountered during drilling and excavation. Documentation is <br /> included in probe drilling/completion logs in Appendix A, the daily construction reports <br /> in Appendix B, and the LFG monitoring probe record drawings in Appendix C. <br /> 3.2.4 Field changes <br /> The following field changes were incorporated into the perimeter LFG monitoring probe <br /> construction: <br /> • All borings were relocated approximately 2.5 feet west of the surveyed design <br /> locations, to avoid encountering or damaging the edge anchor flap of the existing <br /> landfill base liner. <br /> 3.3 LFG Collection Piping <br /> 3.3.1 Description of Work <br /> The 13 perimeter LFG extraction wells were connected to the existing 18-inch HDPE <br /> vacuum pipe on the Landfill. <br /> 3.3.2 Construction Procedures <br /> TRG personnel carefully excavated each of the road crossings to install the 2-inch PVC <br /> well lateral pipes. The existing 18-inch HDPE main header was fitted with 13 <br /> EMCON/OWT <br /> N:\_LANDFIUAWI Austin Road-Forward\2004 SVE CQA\text\report\CQA report final.doc Rev.0,1/5/05 <br /> 3-3 <br />