Laserfiche WebLink
• <br /> LARRY E.O'BRIAN 7985 VANCE DRIVE,SUITE 205A <br /> FOUNDER ARVADA,COLORADO 80003 <br /> STEVAN L.O'BRIAN 303-423-7297 <br /> PRESIDENT FAX 303-423-7599 <br /> September 25, 2014 <br /> r. Tyler O'Donnell <br /> Division of Reclamation, Mining & Safety <br /> 1313 Sherman St, Suite 215 <br /> Denver, CO 80203 <br /> Dear Tyler; RECEIVED <br /> RE: Albert Frei & Sons, Inc. SEP 2 5 2014 <br /> Stagecoach Pit - Update DIVISION OF RECLAMATION <br /> M.L.R.B. Permit # M-1983-067 ISIONOFRECLG AND MATT <br /> ETY <br /> On behalf of my client Albert Frei & Sons, Inc. I am submit- <br /> ting this correspondence to update and keep you appraised of what <br /> Albert Frei & Sons, Inc . , is doing to investigate and mitigation <br /> the ground-water Qround-water isGUPG to the east of the Stagecoach Pit. In <br /> the last update (9/5/14) I laid out a plan to begin investigating <br /> the Zigan Lake overflow drain pipe and to make changes to the <br /> outlet in an attempt to improve or increase the flow thru the <br /> pipe to lower the lake level . In the past this was an accepted <br /> method for regulating the groundwater elevation between the lake <br /> and the Stagecoach slurry wall and it worked for nearly 4 years. <br /> On Friday, September 12, 2014 a "T" was installed on the <br /> discharge end of the pipe. An extension was added to divert the <br /> flow from the catch basin so that the catch basin was taken out <br /> of the line in hopes of improving flow thru the system. A meter <br /> was installed in the discharge pipe so Frei could monitor the <br /> amount of water leaving the Zigan Lake. Once the water began to <br /> flow thru the pipe, the meter registered a flow of between 490 <br /> and 520 feet per minute. Attached are pictures taken on 9/16/14 <br /> showing the newly installed "T" , diversion pipe and the meter. <br /> Note that the catch basin was partially drained. At this level <br /> there is no longer discharge from the basin and we believe that <br /> it will eventually dry up. <br /> The photo taken 9/18/2014, shows the water over the inlet <br /> grate after 6 days the ones taken on 9/25/14 shows, _Ben Frei <br /> standing on the grate in one inch or less of water. We estimate <br /> the lake level had dropped by 8 to 10 inches based on photos in <br /> the inspection report and that approximately 7, 414, 600 gallons <br /> (=22 .75 ac-ft) had been discharged from the lake during the 13 <br /> days. <br /> As®- )01 011 <br /> r / ZK/0 <br />