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NOV-09-2001 FRI 08;40 AM BANK~ND GESSO LLC FAX N0. 3034 8329 P, 05 The proposed mitigation plan states that following mining and lining of the water storage reservoir, the applicant will continue to monitor groundwater levels in the area of the water ski club pond. The applicant will need to clarify the frequency and duration that the water level in the pond will be monitored. It is also unclear if the applicant proposes to monitor the pond before and during the mining activity. The applicant will need to commit to obtaining baseline water levels of the water ski pond and a monitoring frequency for both during and aRer mining. It would also be help/ul if there are any historical water levels of the water ski pond to determine a baseline level. In the immediate area of the mine, groundwater has a saturated thickness of only 10 to 20 feet, in very permeable soils. The site is located less than 0.5 miles from the open channel of the South Platte River in an area where groundwater will demonstrate a high hydraulic conductivity. Seasonal effects, the effects of other mining activity, irrigation, and other well usage are additional reasons why precise local groundwater elevations can be a moving target. Because mining in this historic pit is proposed to begin and be completed within the next two years, and because of the difficulty in defining historic groundwater levels in a specific location near the mine, meanin 1ul baseline water level data for the immediate area of the mine will be difficult n develop The applicant is thus proposing to install three monitoring wells In the area of the water ski~ond~c_shown on the attached monitoring wells will provide a measure of the impacts of dewatering activity. ,~ ~~ Monitoring wells will be installed before dewatering begins. Groundwater elevation in t t s an in t e water ski pond wll a measured at least monthly -~~``~~-J thereafter through minin ag nd reclamation arti.,~ty, Exceptions to this schedule will .gyp occucduring the irngation season of May through 5eatembe[,.when-wate~elevationsanri. be determined at least every other week_Following-completion-of-reclamation stets, water levels will be monitored on a quarterly basis for five quarters_(15 months). One of three monitoring wells will be placed along the southern boundary of the Ski Club's property. A second is proposed for property immediately south of the mine, and the third is proposed for property north of the mine and 124`" Avenue. Agreements with landowners to place monitoring wells on property north and south of the mine have not been finalized at this time; however, the applicant is comfortable that such agreements can be finalized. . The applicant proposes a piezomefer to be placed south of the ski club and south west of the reservoir. Please indicate the location of these piezometers on map, and specify the frequency and duration in which they will be monitored. (For the sake of this application, the words 'piezometer' and 'monitoring well' have been used interchangeably by Banks and Gesso, LLC. Our intended meaning is a monitoring well for determining groundwater elevation.) The monitoring wells will be installed in the approximate locations shown by the accompanying drawing; and the proposed monitoring schedule will be as stated above. • The applicant states that it the Water Ski Club's pond surface decreases by more than 2 feet from the expected seasonal elevation, the applicant will take mitigative measures mutually agreed to by the water ski club and the applicant. Please explain the rationale