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• <br />If the Phase 1 system is capable of adequately capturing the groundwater flowing through tltc. <br />alluvial aquifer, then expansion (Phase 1I) of the system would not be necessary. However, i <br />additional wells are needed to achieve capture. then Phase 11 would involve construction of the <br />additional wells and other system components needed to achieve this goal. Since the scope o <br />Phase II is unknown, this document provides only the scope of work for Phase 1. <br />PH ASE 1 <br />The purpose of Phase 1 is to design the extraction well and discharge collection/conveyancr <br />system, and construct a portion of it for testing. The objective is to develop an overall design fo - <br />the system that can be modified and/or expanded as needed based on findings from pilot testing <br />The following describes the tasks to accomplish this objective. <br />Task 1 — Drill Test Holes and Site Extraction Wells <br />• Purpose: To better define the depth and characteristics of the alluvial aquifer in <br />order to optimize well siting and develop well design criteria. <br />• Scope: We propose to drill up to fourteen (14) test holes to the top of thy: <br />Troublesome Formation along the proposed extraction well system alignment. Thy <br />test holes will be located along the north access road at approximately 50 -foo: <br />spacing, and will be completed with 2 -inch PVC casing for use as piezometers. Thr <br />test holes will be advanced using the dual -wall reverse rotary drilling method to <br />obtain good cuttings samples and to provide an initial estimate of well productivity. <br />In addition, up to 6 more piezometers will be installed at strategic location:; <br />surrounding the proposed extraction well system. These piezometers will be used to <br />monitor water levels for evaluation of groundwater capture. <br />The information obtained from test hole/piezometer installation will be used to selec! <br />the most advantageous sites for extraction wells as well as to develop extraction well <br />system design criteria. Well sites will be selected to enhance capture of seepage b! <br />the overall system, considering alluvial aquifer thickness, lithologic characteristics. <br />and water production rates during drilling. We estimate that seven (7) sites will bi <br />selected for extraction well installation during Phase 1. <br />• Deliverable: URS will prepare test hole lithologic logs, a hydrogeologic cross- <br />section of the extraction well system alignment, and a potentiometric contour map to <br />characterize groundwater levels for non - pumping conditions. These diagrams wilt hi. <br />included with the Design Report (Task 5). <br />