HYDRO24646 - Laserfiche WebLink

Home Browse Search

-~~ ~ ~ ~~ ~~ / CIVIL RES'~URCES,LLC ~j ~+~'t~ ~py-~ ENGINEERS Et PLANNERS February 15, 2007 Y'e~ L ~{g 1 B 2001 Mr. Tom Schreiner ?;.;on: Division of Minerals and Geology ~ DN18tOn ctf`-'~ ~o~y 1313 Sherman Street, Room 215 Mining ~ ~ ~ . Denver, Colorado 80203 RE: December 2006 Groundwater Quality Montt ro ninit g Results, Lupton Lakes Gravel Mine Permit No. M-2004.078 Dear Mr. Schreiner: The following letter report describes the resu_Its from the December 2006 Sampling Event. This report is being submitted in general compliance with approved Groundwater Sampling and Analysis Plan (GWSAP) included in Technical Revision 2 (TR2) to the Lupton Lakes Gravel Permit issued by the State of Colorado Division of Minerals and Geology. GroundwaterMonitoring Results The December 2006 Sampling Event includes monitoring wells (CRMW) 01, 02, 04, 9, and 16. CRMW 41 was not sampled during this event because of extensive snow drifting over and in the area of the monitoring well. Nitrate (as N) exceeded Primary Ddnking Water Standards (PDWS) in four of the five wells sampled with nitrate concentration levels ranging from less than 0.07 to 71.26 mglL in CRMW01. The proposed baseline levels for nitrate were exceeded in wells CRMW01 and CRMW02. However, considering the very limited mining activity that has been completed to date and the fact that these wells are located at the north side of the site (1 mile away from the mining area), these exceedances are not attdbutable to mine activity and should be considered in evaluating approved baseline levels in the area. Fluoride did not exceed the Standards or the proposed baseline levels in all wells tested. Secondary Drinking Water Standards (SDWS) were exceeded for Total Dissolved Solids (TDS) (792 to 1,351 milligrams per liter) consistently across the site, and chloride exceeded SDWS at 252 mglL in CRMW09. The remaining SDWS parameters tested for including pH, Iron, and Sultate did not exceed the SDWS. Additional parameter test results and the summary of all laboratory analysis results are contained in the attached table. Figure 1 shows the location of the monitoring wells and the groundwater elevations measured during the December sampling event. Groundwater contours have been drawn on the figure also based on these measurements. The gradient is northwest toward the South Platte River. The results of this sampling event are consistent with anticipated results when the GWSAP was developed. Further sampling will be completed in April consistent with the approved GWSAP unless the baseline water quality report is approved with the modifications presented to the GWSAP. Please contact me if you have any questions. Sincerely, CIVIL RESOURCES, LLC. Joseph A'. `Jes`ik, P.E. Project Engineer J:1Denverwater-15112007 DMG SamplinglDec06- Itrrptdoc 451 OAK STREET, SLI ITE 209 ~ P. O. BOX 68O ~ FREDERICK, CO 90530 ~ I3O31 833-1 41 6 ~ 133) 833-2650 -FAX