2015-06-03_REPORT - M1999120 - Laserfiche WebLink

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DRMS ANNUAL REPORT - GROUNDWATER MONITORING REPORT SITE: L.G. Everist, Inc. - Fort Lupton Sand and Gravel, M-1999-120 DATE: June -2015 Page 2 of 2 MW14 - The groundwater has dropped below the baseline level, however this well is clearly internal to LGE, as it is located in the southeast section of the Parker-Panowitz cell. Changes in groundwater levels around this well would only affect LGE, therefore no mitigation is necessary. Note that the nearest external wells, MW45 (located just north of the Parker-Panowitz slurry wall) and MW11 (located just north of the released Hill -Oakley reservoir), are in compliance. MW21, MW22, MW 23, MW24 - These wells fell outside of baseline ranges for a short time in the summer of 2014, and it was most likely due to the dewatering and mining in the Sandstead cell. They are all located along the eastern side of Sandstead and are considered internal to LGE operations. All four wells have come back into baseline ranges as we are converting the south half of Sandstead into a settling pond. This conversion into a settling pond is considered mitigation on our part as it is already helping to recharge the groundwater in the area and bring the water levels in the wells back into baseline ranges. Because the wells are internal to LGE operations and water levels would only affect the operator, no other mitigation is necessary. Note that the nearest external well, MW20, located on the west side of Sandstead, has stayed within baseline ranges. MW25 - This well fell slightly outside of baseline ranges in late 2014, possibly due in part to the dewatering and mining in the south half of Sandstead, but also the on-going dewatering by the adjoining mine to the north. MW25 is located at the northeast corner of Sandstead, just across CR18 from the neighboring mining operation mentioned in MW8 and MW9. The water levels in MW25 are very close to baseline ranges, and we expect to see it within baseline ranges this summer due to the conversion of the south half of Sandstead into a settling pond, and the subsequent recharging of the groundwater. There are no neighbors being affected. As mentioned above, all other existing wells are within baseline ranges. Also, as noted above, L.G. Everist has investigated the data and compared monitoring well results with their locations and nearby activities, whether LGE or neighboring mining operations. Most wells that have fallen outside of baseline ranges are internal to LGE operations, and are not affecting anyone but LGE, so therefore no mitigation is necessary. As MW8, MW9 and MW25 are the only external wells that are outside of baseline ranges and are extremely close to our neighbor's dewatering operations, the cause is apparent. The lower water levels are not having an adverse effect on any residences and certainly not on the mining operations. As LGE is not the cause of the groundwater decrease in these three wells, mitigation is not required on our part. We will continue to monitor all external/perimeter wells on a monthly basis. FL-DRMS-AnnRpt&GrwtrMon-2015-060315.docx