Laserfiche WebLink
• <br />E <br /> <br />Laughlin Water <br />E N G I N E E R S LTD. <br />March 31, 2011 <br />Mr. Michael Cunningham <br />State of Colorado DRMS <br />1313 Sherman St., Room 215 <br />Denver, CO 80203 <br />RE: Goose Haven Reservoir No. 2; DRMS File No. M-2010-071 <br />Ground Water Monitoring and Mitigation Plan <br />Dear Mr. Cunningham, <br />As requested we have prepared a ground water monitoring and mitigation plan for mining of Goose <br />Haven Reservoir No. 2 within the City of Lafayette. The plan is described herein and attached (from CTL <br />Thompson) is a summary of proposed monitoring locations. <br />Step 1- Establish Monitoring Well Grid and Baseline Ground Water Elevations <br />CTL Thompson, Inc. has supervised the installation of 7 piezometers (4 up gradient and 3 down gradient <br />from the proposed mining operations) within the City of Lafayette property surrounding the proposed <br />mining operations. Piezometers 1 through 3 have been in service for several years and piezometers 4 <br />through 7 were installed on July 1,9 and 16, 2009. The piezometers are at the locations shown on the <br />attached maps. Water level measurements were made at the time of drilling and several days after <br />drilling. Since that time the City of Lafayette has continued monitoring of the piezometers. The <br />measurements are attached as an appendix. From these measurements we have established the <br />following seasonal baseline ground water elevations. <br />Piezometer <br />1 <br />2 <br />3 <br />4 <br />5 <br />6 <br />7 <br />Ground water elevations will continue to be measured at the established piezometers quarterly starting <br />at the time of permit approval from the DRMS. This will further confirm seasonal water surface <br />elevations for the site prior to mining. In addition, just prior to beginning slurry wall and drain <br />installation, an additional measurement at each well will be completed. Measurements will be provided <br />to the DRMS as part of an annual report. <br />Winter Baseline <br />December 31 <br />Water Elevation <br />5037.9 <br />5036.2 <br />5030.4 <br />5062.6 <br />5060.7 <br />5044.2 <br />5039.1 <br />Spring Baseline <br />March 31 <br />Water Elevation <br />5036.4 <br />5035.9 <br />5030.3 <br />5062.6 <br />5060.7 <br />5043.3 <br />5039.0 <br />Summer Baseline <br />June 30 <br />Water Elevation <br />5039.3 <br />5036.7 <br />5033.7 <br />5064.8 <br />5061.9 <br />5045.9 <br />5041.5 <br />Fall Baseline <br />September 31 <br />Water Elevation <br />5038.8 <br />5036.3 <br />5031.7 <br />5064.1 <br />5061.3 <br />5045.8 <br />5041.4 <br />7 .