Laserfiche WebLink
<br />Specific Comments, WAI Responses, April 5, 1995; Page 3 <br />Upgradient and down gradient piezometers for each Phase would be better. These piezometers <br />should be measured monthly for at least a year. These measurements should be compared to local <br />meteorological information, to the nearest RFETS wells and stream gage. Ideally this information <br />should be incorporated into a ground water model that could test the amount of unsaturated zone <br />that needs to be left to maintain a water balance similar to that now sustaining the downgradient <br />habitat. <br />Phases 2 through 5 in the southern area of the permit application are in an area where the bedrock <br />is shallower and on the other side of the vertical outcrop/subcrop of the Laramie-Fox Hills <br />Aquifer ITOm the nearest RFETS wells. Therefore, piezometers are needed to determine local <br />water levels before mining proceeds. Suggested placement of these piezometers would be: <br />1 -middle of Phase 2 <br />1 -middle of Phase 4 <br />1 -middle of Phase 5 <br />Monitoring in this area is the same as suggested above. <br />This suggested monitoring is minimal, if you have better regulatory requirements such as up and <br />down gradient wells for each area please write them into the permit. The mining plan and <br />monitorinng requirements will need to reflect the requirements of the conservation plan for <br />RFETS. <br />mm nts on Section 16 Permit Number M-94-45 <br />The response to question 7 is misdirected. Recharge to the alluvium is much more sensitive than <br />recharge to the bedrock unless the bedrock were a sandstone tense in the Laramie Formation. <br />Again, perched ground water is mentioned without documentation of "on site" evidence. Perched <br />ground water is a localized phenomena and is not mentioned in excerpted Rocky Flats Ground <br />Water Monitoring Report. Enhancing recharge to alluvium or bedrock may not be desirable in <br />this drainage. A unique ecosystem has developed in response to enhanced recharge to the <br />alluvium and permeable bedrock. The hydrologic balance must be understood and the value of <br />the ecosystem determined before it can be decided that more water is better. <br />Visual observation of the ground water table described in this document is not adequate to protect <br />ground water at this site. The same comments made for the Bluestone Amendment Permit apply <br />here. Additionally, the high ground water table left in the reclaimed pits would be located much <br />closer to already established stands of phreatophytes. <br />