Laserfiche WebLink
assessed relative to one standard deviation from the mean of measurements collected during <br />the applicable season. <br />In addition, wells in river corridor areas adjacent to active mining phases will be monitored <br />monthly during the growing season. If monitoring indicates a drop of 1 foot below the <br />historic baseline or if abnormal vegetation stress is otherwise noticed, dewatering flows or a <br />portion thereof will be directed into established wetland areas and the riparian corridor to <br />maintain the vegetation. <br />In addition to the river corridor, a pond and associated wetlands are located just south of the <br />Phase 2 mining area and immediately south of MW-4. MW-4 will be monitored monthly <br />during Phase 2 mining operations. If monitoring indicates a drop of 1 foot below the <br />historic baseline or if abnormal vegetation stress or pond levels are otherwise noticed, <br />dewatering flows or a portion thereof will be directed into established wetland areas and/or <br />the pond. <br />Groundwater monitoring and modeling indicate that dewatering operations would not have <br />a significant effect on flows in the Jones Ditch. However, Lafarge will enter into an <br />agreement with the Jones Ditch Company that allows for dewatering water to be returned to <br />the ditch to make up losses. This agreement will be in place prior to dewatering and mining <br />south of the Cache la Poudre River. <br />Groundwater modeling (Attachment G-2) indicates that there should be no significant effect <br />on surrounding groundwater wells due to the Parsons mining operation. If Lafarge receives <br />a complaint from a well owner, Lafarge will initiate an evaluation of the cause and notify <br />the DRMS immediately (within 24 hours). <br />After the DRMS has been notified, Lafarge will review the available data and information <br />and submit a report to the DRMS within 30 days. To the extent practicable, the report will <br />identify the extent of potential or actual impacts associated with the changes. The <br />evaluation will include discussions with any well owner who has contacted Lafarge <br />regarding a concern and review of available data from the well and vicinity to evaluate the <br />cause of any changes (e.g., seasonal variations, climate, mining by Lafarge, mining by <br />others, or other factors). Lafarge would also enlist the service of a contract professional <br />hydrogeologic consultant to provide an opinion and meet with the Division to discuss the findings. <br />If the claim cannot be resolved with this information, Lafarge would fund the service of a 3`d party <br />consultant agreeable to the Division to render a separate opinion. If Lafarge's mining or <br />reclamation activities are determined to be a significant contributing factor that has or may <br />create adverse impacts, the mining-associated impacts will be addressed to the satisfaction <br />of the DRMS. <br />An initial temporary mitigation measure (for cases in which Lafarge's operation is a <br />suspected cause) may entail providing an alternative water supply that meets the <br />documented historic well production, or need, until further investigation can be conducted <br />to determine if the well condition is due to Lafarge's mining operation. If, after review, the <br />Lafarge West Inc. - Parsons Mine 7 <br />Groundwater Monitoring and Mitigation Plan