GENERAL42099 - Laserfiche WebLink

Home Browse Search

4.3 APPENDIX C 4.3.5 Monitoring W cekly monitoring of the mud gel in the annulus between the 13 3/8-inch surface casing and 8 5/8-inch well casing will be required and any observed changes and/or amy remedial measures taken shall be reported monthly to the authorized officer. The designated operator/lessee Nrill be required to complete a certain number of wells as dedicated hydrologic monitoring wells. These wells will supplement the proposed monitor wells and wdl be located outside the well field and zone of influence of subsidence, :so they are effective throughout entire mine life. The number and location of the dedicated hydrologic monitoring wells will be submitted by the applicant sod approved by ttie authorized officer before initiating construction of the approved action. Monitoring of the groundwater will tcommence at least 6 months prior to the start of mining, The designated operator/lessce will be required to monitor four groundwater zones: the unconfined water bearing zone (perched aquifer), the A-groove of the upper aquifer, the base of the lower aquifer, and the B-groove of the tower aquifer. The monitoring well(s) shall be equipped with a continuous graphic or other appropriate water level recorders. The well(s) shall be sampled two times, t wcek span, for major end minor components., as soon as completed and cleaned out properly. Sampling for major oomponemts will be conducted at least once a month beginning 6 months prior to and continuing throughout mining operations, and minor components will be sampled annually. Monthly sampling shall continue for a period of up to 3 years (at the discretion of the authorized officer) after project cessation. Any deviation from baseline condition rffects detected within the monitored zones during operations shall be reported to the authorized officer. Sampling frequency will be increased to at least once a wcek if effects to the monimred zones are recorded. The wcekly samples will be analyzed for the field measurements and major ~bmponents. The first wcekly sample will be analyzed for rninor components. If significant deviations from the baseline are recorded in the minor components, analysis of samples For minor components wiU continue. Analysis for only those minor components which show a significant deviation from baseline will be required. Unless otherwise authorized by the authorized officer, the well(s) shall be sampled for the following: Field Measurements (Monthly) temperature pH conductivity Lab Analyses -Major Components (Monthly) total dissolved solids alkalinity sodium bicarbonate carbonate Minor Components (Sample initially and if aquifer system a affected) arsenic aluminum cadmium manganese selenium barium chromium nickel vanadium beryllium copper strontium molybdenum bismuth lead zinc mercury bromide lithium nitrate calcium sulfide magnesium Buoride potassium total phosphate sulphate boron silica iron chloride dissolved organic carbon Lab analysis work must be performed by a laboratory approved by the authorized officer. If leakage (brines) from cavities exceeding State of Colorado standards for total dissolved solids is detected in the base of the lower aquifer, the operator will be required to (l) perform remedial action such as extracting the brines and disposing of them through surface treatment, evaporation, or deep well injection at approved facilities, and/or (2) contain the brines within the base of the groundwater system and within the boundaries of the sodium leases, as determined by the BLM authorized officer. The designated operator/lessee shall establish surface water monitoring stations (or water quantity and quality as required by the authorized officer, upstream and downstream of the cone of depression on the main chanmels of Yellow and Piceance creeks. Data collected at the stations shall include continuous streamflow and precipitation records and comprehensive water quality analysis for all field measurements and major and minor components conducted on a quarterly basis. Data collected shall commence 6 months prior to start up and shall continue throughout mining operations as directed by the authorized officer. Should recorded water quality data deviate significantly from baseline, sampling frequencies may increase as directed by the authorized officer. The lessee shall compile an inventory of all springs and seeps within the cone of depression and monitor for water quantity and quality. Water quantity of springs shall be monitored monthly for 6 months prior to and during mining 4.3-3