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10/4/10 <br />COTTER CORPORATION (N.S.L.) <br />RESPONSE TO THE ADEQUACY REVIEW FOR TECHNICAL REVISION 14 <br />Cotter Corporation (N.S.L.) ("Cotter") responds as follows to each specific Division of <br />Reclamation, Mining & Safety ("DRMS") comment in DRMS' September 28, 2010 Adequacy <br />Review: <br />Paragraph 2. This section appears to be emphasizing "immediate" impacts versus long term. <br />Does Cotter have a different approach for evaluating sources of contamination that might cause <br />long-term impacts versus short-term? <br />Response: _ <br />The word "immediate" has been replaced in the text of item No. 2 in TR-14 with the word <br />"greater" to avoid confusion. The objective underlying the request for TR-14 is to identify and <br />characterize solid source term materials within the alluvial fill for potential excavation and <br />removal. Once characterized, any identified source term material within the alluvial fill can be <br />preferentially excavated where possible, removed from exposure to groundwater percolating <br />through the alluvium, and would thus be prevented from impacting water quality in Ralston <br />Creek. Removal of solid source term materials within the alluvial fill is an important part of the <br />long-term reclamation strategy at the site. TR-14 is crucial to this effort. <br />Paragraph 3. Please provide the expected approximate dimensions of the trenches. What will <br />be the expected number and sampling density/spacing of the soil profile samples? <br />Response: <br />The expected length of each trench will be equivalent to the horizontal excavation reach of the <br />backhoe (approximately 10 feet long). The expected width of each trench will be somewhat <br />wider than the width of the backhoe bucket (about 3 feet wide). The expected depth will vary <br />depending on depth to bedrock, the capacity of the backhoe, and other factors but is generally <br />expected in the range of 5 - 14 feet. <br />Sampling increments within a given trench may vary depending on the results of gamma surveys <br />along the trench walls, but should average 1 or 2 feet between samples unless materials with <br />elevated source term characteristics are identified (in which case more closely spaced samples <br />will be collected). With the ability to survey the trenches in-situ and obtain near real-time <br />sampling results in the on-site screening laboratory, flexibility in depth increment selection and <br />number of samples needed to meet project objectives is possible for this type of radiological <br />survey. <br />The above information has been added to the text of item No. 3 in TR-14.