Laserfiche WebLink
parameters whose historic maximums 'ivrF +reedec' during 6991. S:a.t,nmtr:r, <br />1991 sample was collected et a saaxi.m.n nisls ?' c discharge level, wicn agrees with <br />elevated water levels in the surroundi mc,r f- ring k i.ls. Spoil Spring #2 did not <br />produce sufficient flow for collection of water quality samples during 1991. <br />Water Suitability <br />A discussion of the suitability of both the ground and surface water monitored at the <br />Nucla Mine was presented in Tab 7 of the 1988 Nucla PAP, and reviewed in the 1990 Nucla <br />Annual Hydrologic Report. The suitability of both ground and surface water was assessed <br />using the most stringent recommended standards published by various agencies for domestic <br />water, agriculture or irrigation, and Livestock drinking water. <br />In summary, the quality of water in all aquifers monitored was found to be unsuitable for <br />both drinking water and agricultural uses. Ground water in the vicinity of the Nucla Mine <br />was determined to be suitable for livestock drinking water, although only marginally so, <br />due to the relatively low yield of all aquifers monitored. All surface water monitored <br />was deemed suitable only for livestock drinking water, as was the spring water monitored <br />at Spoil Spring #1. <br />Using the list of parameters and associated limits for livestock drinking water (see Tab <br />7, Nucla PAP), a review of chemical analyses performed on samples collected at monitoring <br />welts (see Appendix E) and at surface water sites (see Appendix C) was made in order to <br />determine whether those water sources found in the Nucla PAP and in the 1990 Nucla AHR to <br />be suitable for livestock drinking water remained suitable during the 1991 water year. <br />Based on the review, the overburden (GW-N9), underburden (GW-N3), and spoils (GW -N27) <br />aquifers were found to be chemically suitable for livestock drinking water during the 1991 <br />water year. The review also determined that water sampled at Spoils Spring #1 remained <br />suitable for livestock drinking water. The Dakota coal aquifer (GW -N4R) was found to <br />exceed livestock drinking water standards in the September, 1991 sample for the following <br />dissolved constituents: lead, magnesium, sulfate, and total dissolved solids (TDS). <br />Analysis for dissolved lead performed on this sample resulted in a value of 110 ug /l <br />which indicates a probable analytical error. Review of previous chemical data for Well <br />GW - N4R shows that livestock drinking water standards for magnesium, sulfate, and total <br />dissolved solids have historically been exceeded in every sample collected. Although the <br />17 <br />