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ALBERT FREI & SONS <br />August 12, 2009 <br />I u6 I ,*d, <br />Mr. David Bird <br />Division of Reclamation, Mining & Safety <br />1313 Sherman St., Suite 215 <br />Denver, Co 80203 <br />Dear Mr. Bird; <br />RE: Stagecoach Pit <br />Permit #M-1983-067 <br />?_re <br />V3 <br />P.O. BOX 700 <br />HENDERSON, CO 80640 <br />(303) 289-1837 <br />(303) 289-2865 FAX <br />RECEIVED <br />AUG 17 2009 <br />*'on of f*eciarnation, <br />Mining and Safety <br />This Technical Revision addresses how Albert Frei and Sons, <br />Inc., will start to correct the impacts the Stagecoach Pit slurry <br />wall is having on the ground water levels east of the mine. It <br />addresses the single corrective action noted in your Inspection <br />Report dated May 27, 2009. In this condition, the Division <br />required us to file a Technical Revision to address the noted <br />highwater in the Zigan Lake and elevated ground water levels <br />noted in the monitoring wells along the east side of the slurry <br />wall. <br />We feel there are a number of contributing factors that are <br />causing the elevated ground water table this year. They are the <br />excessive amounts of rainfall we have seen the past three months, <br />the extended run of water in the Fulton Ditch, changes in the <br />ground water table associated with the numerous lined/sealed <br />gravel mines in this area and possibly our slurry wall. <br />In July we contacted the Zigan Lake homeowner's associa- <br />tion and reached an agreement to install a pump in their lake to <br />regulate the water level. Their records show the lake may be as <br />much as 6 feet higher then historic levels. The agreement was <br />that we would install a pump and pipeline to lower the lake level <br />and they would operate the pump as needed to keep the lake at the <br />level they desire. During pumping, monthly measurements are <br />taken at the monitoring wells by the engineering firm Arcadis-US <br />that will be used to evaluate the impact the lake draw down is <br />having on the groundwater level next to the slurry wall. We need <br />to determine if there is a direct correlation between the lakes <br />elevation and the level of the water behind the slurry wall. <br />Once there is enough data a permanent solution can be designed