HYDRO24289 - Laserfiche WebLink

Home Browse Search

~II'I~II~II~'I~I II~ C c~~us "`~ Yampa Valley November 10, 1993 Kent Gorham Reclamation Specialist Division of Minerals and Geology 1313 Sherman Street, Room 215 Denver, CO 80203 Cyprus Yampa Valley Coal Corporation 29587 Routt County Road #27 Oak Creek, Colorado 80467 303-879-3800 RECEIVED NOV 15 1993 Ci:•rcr^ ct i.~,ner~lg ~ i=uclonv Re: Decrease in Freguencv of Accelerated Water Level Monitoring, Select Fish Creek AVF Alluvial and Shallow Groundwater Wells; Permit C-82-056, Foidel Creek Mine Dear Mr. Gorham; The attached information on well levels is being provided in conjunction with TCC's plan for decreased monitoring frequency for the wells currently being monitored on an accelerated schedule. As noted in our previous telephone conversation, the monitoring plan for the FCAVF wells recommends accelerated sampling at a daily interval for wells affected by drastic changes in water level. In the event no such changes in water level are observed, then the normal schedule outlined in Exhibit 14 applies. TCC wishes to stress that the footnote on the Exhibit 14 page RECOMMENDS daily sampling, rather than requires daily sampling. As can be seen from the attached well level information, only well GWB-2 has exhibited a drastic change in water level. Daily monitoring of this well commenced on October 18 and has been conducted on a daily basis since that time. In addition, TCC has also monitored wells GWA-6, GWAP-7, GWAP-5, GWB-1, GWA-2, and GWAP- 4 on a daily basis since that time as a voluntary measure to gain a better understanding of this hydrologic system. Wells GWAP-7 and GWB-1 have also displayed minor dewatering effects, but this would be expected during localized dewatering of the shallow bedrock aquifer. In the case of GWAP-7, the slight decline in water elevations observed is likely the result of the localized dewatering of the shallow bedrock unit which feeds the immediately adjacent seep FCS-1. At this time the levels in well GWAP-7 have stabilized. Well GWB-1 has also shown a slight decline in water levels, but this decline is of such a slow rate that an increase in sampling interval would not be expected to significantly affect the tracking of water level fluctuations in this well.