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This scenario presumes the Topper well or wells lie down gradient from the proposed <br />pit. The local gradient is not known. Topper's exhibit features a sand channel that <br />crosses from the proposed operations area to the Topper property running sub-parallel <br />to the South Platte. Because this sand channel contacts aquifers from which the <br />Toppers draw water, and because the hydrologic gradient for the shallow alluvial <br />aquifer at least would be generally down river, it is reasonable that mining activities <br />affecting groundwater chemistry might appear in down gradient wells, including the <br />Toppers'. <br />Therefore, I would recommend that Aggregate evaluate the local hydrologic gradient <br />and from that develop a groundwater geochemistry evaluation and monitoring plan <br />and a response plan. <br />2. Topper raised objections related to Aggregate's NPDES "general" dischazge permit. <br />One is that the permit was not staged for public review. DMG has no jurisdiction <br />over this issue so cannot address it. Another objection is that the discharge permit is <br />general rather than site specific. Again, this is not within the jurisdiction of the <br />DMG, so we cannot address it. <br />A related issue is that DIMP, and presumably other contaminating compounds or <br />elements from the Rocky Mountain Arsenal, are not monitored by the NPDES permit. <br />Topper's exhibits indicated that CDPHE recommended that Topper implore DMG to <br />ask CDPHE to add DIMP to the NPDES monitoring. I do not believe it is DMG's <br />obligation to intercede on this issue. Whether DIMP or other compounds from the <br />Arsenal reach surface water via an NPDES discharge is not within DMG program <br />authority. <br />Another discussion in the Pre-Hearing Conference centered on set-backs from <br />properties and permanent structures. I would consider the following: <br />a. Encroachment Agreement between Aggregate and South Adams Water & <br />Sanitation District (May 6, 2003), <br />b. letter from South Adams W&SD (April 25, 2003) regarding encroachment <br />onto the sewer easement, <br />c. Pre-Hearing discussion, <br />d. Mining Plan Map (Exhibit C-2, sheet 2 of 2) <br />Based on these, it appeazs that Aggregate maybe interpreting the definition of <br />"mining" differently from the Division. The map states "No mining within 200' of <br />South Adams Water & Sanitation District Sewer Line without DMG approval of <br />agreement with the district." The encroachment agreement cleazly indicates that the <br />sewer easement is not to be encroached upon; i.e. it is not to be used for "mining" as <br />defined in the Rules and Regulations, meaning it should not be excavated, used for <br />topsoil storage, or even driven over. <br />Therefore, the permit application needs to be clarified. Either Map C-2 should be <br />revised to cleazly indicate that topsoil shall not be placed above the sewer easement <br />and that the sewer easement shall not be used for site access; or the agreement should <br />