2020-06-04_PERMIT FILE - C1981008A (2)

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the West Lateral splitte flume to Site SW -N106. The greatest percentage of lost flow (30 percent) occurred in the reach between the "Benson's Corner" box (13) and SW -N105 (14). Along this reach, a significant portion of the ditch banks are heavily vegetated with willow, wild rose and a variety of grasses that commonly exhibit high rates of transpiration. Interestingly, two reaches showed again in discharge. Between Site SW -N104 (5) and the "cemetery" box (8), an increase in flow of 1.5 percent (from 19.4 to 19.7 cfs) was observed. Also, between the "halfway" box (10) and the "bend" box (11), a 12.6 percent increase in flow was observed (from 15.9 cfs to 17.9 cfs). Most reaches along the West Lateral lose irrigation flow to diversions, evapotranspiration and, of course, seepage. The reaches that showed a loss in flow had water being withdrawn along each reach through diversions on the day the study was performed, as well as significant lengths of heavily vegetated bank sides. Seepage of irrigation water occurs along the entire reach of the West Lateral, probably occurring at higher rates and volumes along the "ridge -top" reach where the ditch was excavated through the shallow soils into the highly fractured sandstone. The two reaches where the ditch featured gains in flow are portions of the general "ridge -top" segment of the West Lateral. The ditch channel bottom in this reach is largely fractured and weathered sandstone, and likely results in relatively large amounts of seepage. This seepage, in combination with localized intensive "flooding -type" irrigation, travels laterally through the shallow soils and fractured sandstone eventually flowing back into the West Lateral slightly downstream. The combination of fractured, weathered sandstone channel bottoms in the ditch and localized "flood -type" irrigation along these two gaining reaches likely resulted in the measured gains in flow. In two different phases during 2001 and 2003, Western Fuels placed the portion of the CCC West Lateral Ditch that either traverses the mine property or parallels the permit boundary on the south into a two different High Density Polyethylene (HDPE) pipelines. One is a 26" pipe and the other is a 12" pipe. The larger diameter pipeline, which holds the majority of the ditch water and functions as the replacement for the old, open CCC West Lateral Ditch, has its intake up ditch and its discharge down ditch of the mine permit area. Accordingly, the ditch water in this pipe no longer has any contact with mine land nor does the mine land have any contact with the ditch water. The 12" pipe line shares the same intake point has the 26" pipe Map 2.05.3(3)-3 shows the location of the temporary and permanent placement HDPE pipelines. The location of the temporary 26" pipe as shown, allowed mining under and adjacent to the permanent CCC West Lateral Ditch location. Upon completion of reclamation regrading and seeding, the pipeline was moved into approximately into the original CCC West Lateral Ditch right of way. The temporary 12" pipeline was removed in the year 2006 when the mining progress eliminated the need for irrigation water in advance of the mine. However, the same 12" pipeline was permanently relocated and buried in the reclamation and furnishes irrigation water to fields owned by New Horizon, Burbridge, GW46 Irrevocable Trust and other land owners. Surface water Site SW -N104 lies on the West Lateral irrigation ditch just upstream of the northeastern boundary of the New Horizon 2 mining area (see Map 2.04.7-1A). Monitoring of water quality at this site (when the ditch is on) was conducted on a monthly basis since July of 1986. Water quality data collected at this site since 1986 is contained in Appendix B of Attachment 2.04.7-5. The irrigation water sampled over time at SW -N104 exhibited a calcium bicarbonate sulfate type (Attachment 2.04.7-10 (Peabody Appendix 7-8).. The mean pH value at SW -N104 is 8.09, ranging from 7.71 up to 8.42. TDS averaged only 179 mg/1, and ranges between 116 and 264 mg/l. TSS averaged 56 Page 2.04.7-24 March 2017 (TR -77)