Handouts from the January 11, 2006 Council Meeting

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Mr. Ron Wickham Page 3 January 11, 2006 Anderson Brothers Construction 0.3 feet per day. Considering the higher velocity and no retardation of the petroleum plume, it would travel about 550 feet in 5 years; plumes from limited petroleum releases typically stabilize and attenuate before traveling several hundred feet. Leak detection measures should also be included in the SPCC plans, including installation and sampling of shallow groundwater monitoring wells. We plan to assist Anderson Brothers Construction with developing a monitoring network and schedule, once logistics of the operations are chosen. The monitoring wells will be 2-inch diameter SCH 40 PVC, screened across the groundwater table and installed in accordance with Minnesota Department of Health regulations. The monitoring wells will also be used to measure groundwater levels. Mining operations reportedly will require about 2 million gallons of water to be pumped per year for this site, roughly equal to pumping 4 gallons per minute continuously. Given the hydrogeologic conditions and estimated aquifer properties, we estimate that this would cause the water table to drop less than 1 inch beyond 500 feet from the well; the farther from the well, the less the drop will be. In our opinion, this will not noticeably affect nearby water wells or lakes. Furthermore, the pumped water will be used to "wash" clay and silt from the gravel, after which the water will infiltrate to the aquifer; the silt and clay sediments will be reclaimed from the infiltration basin and mixed with Class 5 aggregate. In our opinion, mining operations, if done properly following an appropriate SPCC plan, do not pose a significant risk to either the underlying aquifer or surrounding surface waters. Closure We look forward to presenting our findings at the upcoming Pequot Lakes City Council meeting. If you have any questions regarding this letter, please call us. Sincerely, GM C. I Senior Environmental veer Enclosures: Regional Location Diagram Nearby Water Wells diagram List of nearby water wells in the CWI database Resume cc: Pequot Lakes City Council RWP:fhs I I:VwpXReviewAlxiCommentLetter.doc GMIE CONSULTANTS,INC.