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The owner reports this well is 42 feet deep, 6-inches in diameter and is used to irrigate 1.5 acres <br /> at a pumping rate of 12 gallons per minute. Mining on the Lafarge Brown property is not <br /> expected to have significant effects on this well because primary mining/dewatering activities <br /> near the well will be on the opposite side of the Cache La Poudre River. <br /> MONITORING AND MANAGEMENT <br /> Groundwater Monitoring <br /> Fourteen monitoring wells were installed in the area as shown in Figure 1. Three of the wells are <br /> on the Lafarge Brown property. Groundwater level monitoring of the three Lafarge Brown wells <br /> began in November 2008 and will be conducted on a bi-monthly to quarterly basis prior to <br /> mining to establish a site-wide baseline. Once mining begins, monitoring will be conducted on a <br /> monthly to bi-monthly basis until a quasi-steady state condition is reached (during initial <br /> dewatering), and on a quarterly basis thereafter until one year after reclamation is complete. <br /> Table 1 provides the existing groundwater level measurement data for the site 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 DBMS 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 immediately. 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 potential <br /> mitigation procedures as 2 feet of drawdown relative to historic conditions. The amount of <br /> drawdown relative to the mitigation trigger point would be calculated and assessed relative to <br /> one standard deviation from the mean of measurements collected during the applicable season. <br /> Greeley 35`h Avenue Mine(M-1977-036) <br /> DRMS 112 Reclamation Permit Amendment Application <br /> Groundwater Monitoring and Mitigation Plan <br /> Page 3 <br />