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warranted. The monitoring site would be located in the southwestern portion of the permit area <br />and would be located immediately down gradient from the limit of mining disturbance. <br />Therefore, after permit approval and prior to new disturbance, three (3) new ground water <br />monitoring wells were installed in the southwestern portion of the NHN permit area. The locations <br />of these 3 new wells are shown on Map 2.04.7 -1. New ground water monitor well GW -N56 will <br />monitor the underburden (UB), well GW -N57 will monitor the coal zone (Coal) and well GW- <br />N58 will monitor the overburden. GW -N56 was completed on August 8, 2012 while GW's N57 <br />and N58 were completed on August 9, 2012. The completion diagrams for the three new monitor <br />wells are shown on Figure 3 of Appendix 2.04.7 -1. These wells will be monitored and reported <br />on the same cycle as the other ground water monitoring wells. It is anticipated that these wells <br />will become the points of compliance after review of additional data and consultation with DRMS. <br />Overburden Zone Ground Water Quality Water level monitoring and the piezometric maps <br />show the nearly immediate response of most of the nine new monitoring wells to the seasonal <br />surface irrigation with water levels going up and down corresponding to the periods when water <br />is in the 2nd Park Lateral Ditch. The impression is that the Overburden Zone is annually being <br />flushed with relatively good quality irrigation water. This further suggests that water quality <br />would improve during periods of irrigation and deteriorate during periods when the ditch is dry. <br />However, comparison of the ground water quality data (see Appendix 2.04.7 -1) with the water <br />level data reveals no such correlation. Table 2.04.7 -1 is a summary of the water quality analyses <br />for the Overburden Zone, showing the minimum, maximum and average values of the analyzed <br />parameters. No data for overburden monitoring well GW -N55 is shown as this well was nearly <br />dry to the point that there was not enough water to collect water samples. The summary of the <br />analyses for wells GW -N49 and GW -N52 are also compared with the WQCC (Regulation 41, <br />The Basic Standards for Ground Water) drinking water and agricultural quality standards. The <br />results show the overburden water quality to be unsuitable for domestic drinking water primarily <br />for sulfates. With the exception of calcium and bicarbonate, the water quality at GW -N52 is <br />better than that at GW -N49, most probably the result of being located closer to the seasonal more <br />alkaline recharge from the 2nd Park Lateral irrigation ditch. The values for pH at GW -N52 are <br />also somewhat higher (more alkaline). Again, suggesting that being closer to the main source of <br />recharge (the ditch) affects the water quality to a greater extent at GW -N52 than at GW -N49. <br />Coal Zone Ground Water Quality Quarterly groundwater quality samples were collected from <br />the three wells (GW -N48, GW -N51 and GW -N54) beginning on October 10, 2008. The <br />groundwater quality data is contained in Appendix 2.04.7 -1 along with the water level and graph <br />information. Review of the coal zone quality does not clearly reveal any correlation with the <br />irrigation seasons, although there is a slight increase in Ca, CaCO1, SO4 and total dissolved solids <br />(TDS) during the winter months when the ditch is not running. It may require a few more <br />seasonal irrigation cycles to validate this initial impression. Again, the monitoring well located <br />furthest up -dip and closest to the recharge area (GW -N51) has better water quality. As an <br />example, the average TDS at GW -N51 is 950 mg/1 compared with an average at GW -N48 of <br />1,592 mg/1 and an average TDS at GW -N54 of 5,058 mg/1 which is located the furthest down -dip <br />and away from the recharge area. Table 2.04.7 -2 is a summary of the Coal Zone ground water <br />quality showing the min/max and average parameter values since monitoring began. Water <br />quality for the Coal Zone at GW -N54 is the poorest of quality of all nine of the new monitor <br />wells. The values when compared with the WQCC water quality standards clearly show that <br />water from the Coal Zone is unsuitable for domestic drinking water. <br />Section 2.04.7 Page 8 October 2013 (TR -05) <br />N: \WFC \2013 \NHN \DRMS Permit Revisions \TR -05 \2.04.7 Hydrology Description_TR- 05.dou <br />