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<br />Aopnad rrr'GWarito! MmitWYgMm~ fw the Nne Nwvon Mine 3 <br />irrigation period. The underburden below the Dakota Coal seams was monitored at wells <br />GW-N13, GW-N16P1, GW-N19, and GW-N34. Water levels varied with the irrigation <br />season simdar to the upper aquifers. The variation was between 5 to 8 feet with well GW- <br />N34 being artesian during the peak irrigation period. <br />Groundwater quality data collected for the 12 wells in the area of the New Horizon Mine <br />2 are contained in Appends E A summary of conductivity, Ph, temperature and dissolved <br />solids for the non-irrgatoa and irrigation seasons is contained ut Table 5 with tn7inear and <br />stiff diagrams contained in Appendix F. Well completion and aquifer test data are wntained <br />in Appendix G. <br />Water quality in the Calamity Draw alluvium as monitored at well GW-N22 is a mixed <br />calcium/magnesium-sulfate type water. The ionic balance of this well does not change during <br />the shift from the non-irrigation season to the irrigation seasoa. The Beld parameters and <br />TDS as summarized on Table 5 are also consistent for both periods. Water quality of the <br />overburden as monitored at the three well sites is variable. Quality of well GW-N15 is a <br />strong magnesium-sulfate wh0e wells GW-N18P1 and GW-N21 are amixed calci- <br />um/magnesium-sulfate type water. Only well GW-N21 exhibits a shift in water chemisuy <br />• from the non-irrigation season (magnesium-sulfate) to the irrigation season (calcum-sulfate). <br />A slight shift in water quality is also indicated fry the field parameters and TDS values <br />indicated at well GW-N18P1 ('fable 5). Water gnality in the Dalwta Coal is also variable. <br />Wells GW-N14 and GW-N17P1 exhibit a strong sodium-sulfate type water while wells GW- <br />N20 and GW-N30 are mixed calcium/magoesium-sulfate. There is a minor shift in water <br />quality during the irrigation with some increases in magnesium levels. Field parameter and <br />TDS values of the coal wells do not indicate drifts during the two seasons (Table ~. All <br />tluee of the coal wells exhibit a lower Ph than other wells with the water being on the acidic <br />side of the scale. Water quality in the underburden 1s slightly variable with the water being <br />a mixed magrtesium/calcium-sulfate type water. At site 16, the only chemistry which could <br />be found in the data base was for well GW-N16. This well was a strong sodium-bicazbonate <br />type water. In the otlur three wells, there is a minor shift in the quantities of magnesium <br />and calcium from the non-irrigation season to.the irrigation season. Field pazameten and <br />TDS values remain the same between the two seasons (Table 5). <br />Table 3 shows the water quality standards for livestock, drinking water, and agricultural <br />standards for Colorado. Groundwater monitoring welts had minor exceedances of iron <br />and/or manganese for drinking water standards in all of the wells. <br />Livesmck standards were not exceeded in airy of the wells during the sample period. <br />Drinldrtg water standards for iron, tnangancse, and sulfate were exceeded at wells GW-N19 <br />(underburden GW-N20 (Dakota coals and GW-N21(overburdcn). Monitoring went GW- <br />N19 and GW-N20 also failed drinking water standards for the ammonia-nitrogen standard. <br /> <br />Attachment 2.04.7-5-30 <br />