REV96006 - Laserfiche WebLink

Home Browse Search

TR9PP8R MINtNG Ipc. III IIIIIIIIIII11111 Mr. Joseph J. Dudash Environmental Protection Specialist Colorado Division of Minerals & Geology 1313 Sherman Street, Room 215 Denver CO 80203 Deaz Ice: September 20, 1996 n i . r^ I_ I \ 11- I j SFP 2 4 f99h J{lgSlUfl U' ri.•,i;~.•.:Iv L•. U',U'~U'~, Re: :Trapper Mining ]nc., Permit No. C:81-0]0, Technical. Revision TAfi9. Ashmore Pit Slide Remediation. In 1995, CMDG approved Technical Revision TRfi9, for [he remediation of a slide area at the south end of Ashmore Pit. The revision requires a report with the results of the monitoring within two months of monitoring completion, September 1996. The monitoring included 1) water level elevations, 2) flow from the french drain, 3) visual inspection of the diversion ditches, and 4) visual inspection of land movement markers. Results of the years monitoring indicate no problems with the remediation work. l) Water Level Elevations Two piezome[ers were installed [o monitor the remediation area. The locations, as approved by the Division, were at the nosh and south ends of the area. Table TR69-1 presents the monitoring information for the study period. The piezometers aze referred [o as "North" and "South" as dictated by the location within the study area. Figures TR69-1 and TR69-2 illustrate water levels for each piezometer. Data presented illtuvales seasonal water elevation changes as would be expected for their shallow depths. In addition, the down gradient piezometer has a higher water level than the upgradien[ piezometer which would also be expected. 2) French Drain Discharge Discharge from the french drain was measured using a bucket and stop watch to obtain a flow in gallons per minute (gpm). As shown, flows were relatively consistent through the sample period (Table TR69-1). Flows were usually less than .5 gpm. 3) Diversion Ditches Two diversion ditches were installed across the remediation area. Inspections of these structures showed no prob- lems through the survey period (Table TR69-1). 4) Land Movement Markers The land movement markers were observed during the survey period and showed no movement within the reme- diation area. Results of the observations for the slide remediation area indicate [hat the area is stable. Therefore, Trapper pro- poses to discontinue monitoring of the area except for normal management practices and maintenance. The pie- zometers would be removed, and recontouring and reclamation efforts began with the surrounding areas. Sinc~e%/yr~~ly~, -~/ ~6' /G Forrest V. Luke Environmental Manager L W Wjab IDMG19609I0t EivJ c Fl1c 109]].0 P.O. Box 787 Craig, Colorado 87626 (303) 824-4401