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The four holes that were fitted with casings are Test Holes 1, 3, 6 and 8. We <br />question whether the four holes described will enable a sufficient understanding <br />of groundwater movement and slide behavior, and we anticipate that the drilling <br />of additional holes may be necessary. No drilling was conducted outside of the <br />slide block itself; if a cutoff drain is warranted to intercept groundwater above the <br />slope, it will be necessary to know the subsurface conditions, e.g. depth to <br />bedrock, in that area. Similarly, to accomplish design of any proposed dewatering <br />activities, an understanding of groundwater conditions in the drainage upstream of <br />the slide may need to be established. <br />Please provide explanation for inclusion in the permit, addressing how the <br />data from the four cased holes will be used in the analysis of the failure <br />mechanism and design of proposed remediation efforts, along with a <br />description of any additional field investigation methods that are likely to <br />occur, in light of the apparent data limitations noted by the Division.