PERMFILE68332 - Laserfiche WebLink

Home Browse Search

OCT-30-2001 TUE 02;54 PM BANKS ~ GESSO LLC FAX N0. 303 ~ 8329 P, 07 northwest and downgradient of the mining area. In addition, local groundwater is exposed within the pond of the Henderson Water Ski Club, approximately 500 feet west of the proposed mining area; and there are likely several unpemlitted, shallow wells, used for non-domestic needs of the residences along 124'" Avenue, north of the proposed mining area. The Applicant acknowledges that shallow welts along 124'" Avenue and the pond of the water ski club will likely be impacted by dewatering o1 the mine site. This pond, the one permitted well, and any unpermitted, shallow wells are generally downgradient and within a quarter mile of the site. The unconsolidated alluvium of the area is relatively permeable, and the groundwater has a saturated thickness of 10 to 20 feet. Because this mining and reclamation project will start and finish in an approximate 2,5 year period, and because placement of a clay liner will occur concurrently with mining, any impacts to groundwater will be short lived. The Applicant is proposing a mitigation plan to include the following steps: • When permitted or non-permitted, shallow wells along 124'" Avenue show decreased capaclty, unsatisfactory to the landowner, the Applicant will pay the landowners water bill from the South Adams County Water and Sanitation District from that time through completion of mine reclamation steps. It is the Applicant's understanding that all landowners with non-permitted wells along 124°i Avenue between State Hwy 85 and the Fulton Ditch ere also connected to the District. For most of these landowners, connection to the District's water supply occurred when contamination of shallow groundwater, originating from the Rocky Mountain Arsenal, was discovered to have reached this area. By paying water bills, the Applicant will be directly compensating the well users for any losses due to decreased well capacity, • The Applicant will place 810,000 in escrow before mining is initiated to pay for rehabilitation of shallow wells along 124'" Avenue that lose efficiency during mine dewatering activities. • Dewatering facilities from the mine will 6e designed to allow discharge to the Fulton Ditch or directly to the Henderson Water Ski Club. Discharge to the Water Ski Club and maintenance of the water level in its pond will have the effect of recharging groundwater immediately downgradient of the mine. ~ Following mining and lining of the water storage reservoir, the Applicant will ,~ ~ continue to monitor groundwater levels in the pond of the water skl club to ensure ~ `~" that the lined reservoir will not have a damming effect on-g~oundwater and cause ~.~c~ ~ ~ signl}icantly lower groundwater elevation in the pond of the Water Ski Club. Water tzD~.~' ~ ' ' level in the pond of the Ski Ctub will be compared with the local groundwater ~5 , ~ ~ elevation, as measured by a peizometer to be placed south of the ski club and L.~c~~'(`4- ' ~~;;UU south and west of the reservoir.-A-lower elevation of groundwater in the pond as ~ ~ ~ 2 ~ ~ ' compared to that msasured-by peizometer will be interpreted as attributable to a ,!~ ~~,1,` 1~C \ damming effect of the reservoir. The peizometer will be installed when mining ~1 , activity is initiated so that groundwater elevations can be recorded on a,regular a~,ti ~ ~ ~ ~ x 15 ' basis, and a relationship between pond level and groundwater level, as'measured ' ' ., r r,) . ~ r~ ^ ~"°~ ~ ~ ~by peizometer, can 6e established. If the Water Ski Club s pond surface N , ~ decreases by more than.2 fee rom the expected seasonal elevation, the Applicant ~ will take mitigative measures mutually agreed to by the Henderson Water Ski Club ~~ ~~ and the Applicant. Such measures could include the installation of a french drain (. S ,~ 4n ~ ~ 1 c ~'~~~~i~~' ~' - ~ r fi~