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MONITORING AND MANAGEMENT <br />Groundwater Monitoring <br />Six monitoring wells were installed in the area as shown on the map of Exhibit C. Three of the <br />wells are on the Lafarge Brown property. Groundwater level monitoring of the three Lafarge <br />Brown wells began in February 2009 and will be conducted on a monthly to quarterly basis prior <br />to mining to establish a site -wide baseline. Once mining begins, monitoring will be conducted <br />on a monthly basis with water levels reported in the Annual Reclamation Report. Once a steady <br />state condition is reached, Lafarge may choose to adjust the monitoring interval to bi- monthly <br />then quarterly basis that will have to be approved in a Technical Revision submitted to the <br />DRMS. Table 1 provides the existing groundwater level measurement data for the site <br />piezometers. <br />Reporting <br />Lafarge will prepare and submit a report on baseline groundwater levels, utilizing data from the 3 <br />existing Lafarge Brown monitoring wells as well as other monitoring wells in the monitoring <br />program. Thereafter, groundwater monitoring data will be submitted with the annual progress <br />report to the DRMS and copied to the Weld County Department of Planning Services. If Lafarge <br />receives a complaint from a well owner, Lafarge will submit their groundwater monitoring data <br />to the DRMS within 24 hours. A copy will also be provided to the Weld County Department of <br />Planning Services. <br />Wells Within 600 Feet <br />As discussed above, there is one permitted irrigation well within 600 feet of the proposed permit <br />boundary. Lafarge will attempt to obtain a 600 -foot well spacing agreement statement from the <br />well owner at least six months prior to the commencement of the relevant mining phase. <br />MITIGATION <br />Monitoring data will be used to help identify potential changes in alluvial groundwater flows or <br />elevations associated with mining and reclamation activities. Baseline data collected from the <br />monitoring program will provide a range of water levels associated with pre - mining groundwater <br />conditions. Experience at other sand and gravel mine sites in similar geologic settings, and <br />baseline monitoring conducted to date, indicates that groundwater levels tend to fluctuate up to <br />several feet per year, being highest in the summer and lowest in the winter and early spring. <br />Due to normal seasonal fluctuations, Lafarge proposes to define the trigger point for the start of <br />potential mitigation procedures as 2 feet of drawdown relative to historic conditions in the <br />applicable season. The amount of drawdown relative to the mitigation trigger point would be <br />calculated and assessed relative to one standard deviation from the mean of measurements <br />collected during the applicable season. Mitigation measures would be implemented after receipt <br />of an owner complaint and confirmation of the two foot trigger point. Potential mitigation <br />measures are discussed below. <br />Greeley 35`" Avenue Mine (M -1977 -036) <br />DRMS 112 Reclamation Permit Amendment Application <br />Groundwater Monitoring and Mitigation Plan <br />Page 3 <br />