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r .max«r.a.:.. <br />5.1.3 Monitoring Wells <br />Per regulatory requirements, dedicated monitoring wells have been constructed to <br />monitor four water - bearing zones; Perched, A- Groove, B- Groove, and the Dissolution <br />Surface aquifers. The aquifers are monitored at several locations across the solution <br />mining area; down - gradient, up- gradient, remote down - gradient, and east in panel 2. <br />Refer to Figure 3: Plant and Well Location Map for well locations. <br />Baseline data were obtained prior to ground water pumping from water well (90 -1), and <br />from mining activities from 1991 through the present. Within NSI's lease boundaries, <br />there are three aquifers defined by US EPA as underground sources of drinking water: <br />the Perched, A- Groove and B- Groove Aquifers. The Dissolution Surface Aquifer is not <br />designated as an underground source of drinking water (USDW). <br />The Perched Aquifer is characteristically low in total dissolved solids (TDS), <br />conductivity, fluoride, SAR (sodium absorption ratio) and moderate to high in sulfate and <br />pH. The A- Groove and B- Groove aquifers are similar in water quality with moderate <br />TDS, conductivity, SAR, but high fluoride. However, the B- Groove aquifer generally has <br />slightly higher levels of TDS, conductivity, SAR and fluoride. The Dissolution Surface <br />Aquifer is characterized by very high TDS and conductivity, high SAR, magnesium, <br />potassium, and moderate pH. <br />Water quality results are carefully monitored to detect anomalies and address them to <br />prevent negative impact on USDW's. The results from 2012 indicate that solution <br />mining is not impacting the Perched, A- Groove or B- Groove aquifers regionally. <br />Appendix A contains detailed sampling results for all ground water monitoring wells. <br />5.1.4 Process Ponds <br />The process ponds at the NSI site have a secondary liner, which collect and direct any <br />condensation or leakage to the leak detection tube for removal. Weekly collection and <br />removal of leachate continued in 2012. Process pond information is provided on a <br />monthly basis. <br />Daub & Associates, Inc. 16 NSI Annual Report 2012 <br />