Laserfiche WebLink
r <br /> As indicated in Scenario 5 and shown graphically in Figure 7 and 8 of the modeling report,the simulated cumulative <br /> effect of the groundwater for the area after the slurry wall is installed around the Phase 2(now East cell, Phase 3), <br /> has no impact on groundwater levels in the Morgan Smith Natural Area. <br /> Based on the groundwater model,there will be no impact to the Brighton or Brantner Ditches from mine dewatering <br /> operations. <br /> Groundwater monitoring and evaluation of potential mining or reclamation impacts shall be conducted as part of the <br /> Groundwater Monitoring and Mitigation Plan. The monitoring plan was reviewed and approved by the Division with <br /> the original permit and will be used during mining and reclamation activities. The plan is outlined below. <br /> To establish a baseline,Aggregate installed 17 monitoring wells at the mining site and is measuring water levels <br /> monthly prior to beginning of mining, and quarterly thereafter. (Note: MWA 1 was removed during Todd Creek <br /> Metropolitan District's construction of a water pipeline and MW-2 on the Bloom property can no longer be found. <br /> MW-2 will be replaced with a new well in roughly the same location. The monitoring plan will now consist of 16 <br /> monitoring wells. Monitoring data will be used to identify potential changes in alluvial groundwater flow or elevation <br /> associated with mining and reclamation activities. Baseline data collected from the monitoring program will provide a <br /> range of relative water levels associated with pre-mining groundwater conditions. Experience at other sand and <br /> gravel mine sites in similar geologic settings has found that groundwater levels tend to fluctuate between two to four <br /> feet each year, being highest in the summer and lowest in the winter and early spring. <br /> • If,during mining,the relative seasonal groundwater elevation at any of the domestic wells or monitoring wells <br /> differs from the baseline conditions by more than two feet,and the condition was not observed during baseline <br /> monitoring,or if Aggregate Industries receives a complaint from any well owner within 600 feet from the site <br /> boundary,then Aggregate Industries will evaluate the cause and take action within 30 days and the DRMS will <br /> be notified. <br /> • After the DRMS has been notified.Aggregate Industries will review the available data and information and <br /> submit a report to the DRMS within 30 days. The evaluation will include discussions with any well owner who <br /> has contacted Aggregate Industries regarding a concern and review of baseline data from the well and vicinity to <br /> evaluate whether changes may be due to seasonal variations,climate, mining,or other factors. The report will <br /> identify the extent of potential or actual impacts associated with the changes. If the extent of groundwater <br /> changes due to mining or reclamation activities is determined to be a significant contributing factor that has or <br /> may create adverse impacts.the mining associated impacts will be addressed to the satisfaction of the DRMS. <br /> Aggregate Industries will begin to implement one or more mitigation measures if mining and reclamation activity <br /> is determined to be a significant contributing factor to groundwater changes requiring mitigation. If, however,a <br /> subject well has not been put to beneficial use prior to mining,then Aggregate Industries would have no <br /> responsibility to provide mitigation. <br /> • Mitigation measures may include, but are not limited to: <br /> - Cleaning a well to improve efficiency. <br /> - Providing an alternative source of water or purchasing additional water to support historic well use in <br /> terms of water quantity and quality. If needed,water quality parameters will be checked in affected <br /> wells to ensure <br /> - alternative sources support the historic use. <br /> - Modifying a well to operate under lower groundwater conditions. This could include deepening existing <br /> wells or lowering the pumps. All work would be done at Aggregate Industries'expense except for <br /> replacing equipment that was non-functional prior to mining. <br /> Aggregate Industries Tucson South Resource <br /> Permit#M-2004-044112 Permit Amendment <br /> Page G-5 <br />