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Upper Curtis C7eek and FF Tributary AVF <br />The Upper Curtis Creek AVF lies approximately '/a mile downstream of the <br />Northern No. 1 mine portal and approximately two miles upstream of the Rienau <br />No. 2 surface facilities. This AVF contains 85 acres of flood-irrigated and sub- <br />irrigated meadow. The alluvial deposits range from 400 to 1000 feet in width and <br />extend from the confluence of the FF Tributary with Curtis Creek, downstream <br />approximately one mile. <br />The FF Tributary AVF lies immediately downstream of the Northern No. 1 surface <br />facilities. The alluvial deposits are 200 to 400 feet wide near the FF Tributary <br />confluence with Curtis Creek. The deposits narrow to less than 150 feet maximum <br />width upstream toward the surface facilities. The FF Tributary AVF contains 6.4 <br />acres of flood-irrigated and sub-irrigated meadow. <br />The original mine plan for Northern No. 1 proposed mining of the FF seam <br />underneath the Curtis Creek and FF Tributary AVF's. The west entry would have <br />crossed under Curtis Creek with 200 to 300 feet of overburden. There are <br />indications that Curtis Creek occupies its present position due to fracture lineaments <br />existing along its valley. Undermining of the AVF would have created the <br />possibility of partial dewatering of the AVF due to contact with surface water <br />through the fractures. No further mining is proposed by the applicant at Northern <br />No. 1 and reclamation of the facilities has been completed. <br />The present workings at Northern No. 1 are limited to an entry driven north <br />1500 feet from the portal and an entry off the north main driven west 500 feet. <br />Mining to the west does not extend under the FF Tributary valley. Neither the FF <br />Tributary nor the Upper Curtis Creek AVF has been impacted by mining to date. <br />The portal at Northern No. 1 has been sealed and the water level in the mine has <br />risen. Currently, all surface runoff is routed to a sediment pond. Any present or <br />residual impacts to the Upper Curtis Creek or FF Tributary AVF's due to fhe <br />Northern No. 1 Mine are negligible. <br />The FF seam is an aquifer that discharges water to the surface system by springs <br />and seeps along its outcrop. The limited extent of mining at Northern No. 1 has <br />minimized the impact that dewatering of the aquifer might have caused. The impact <br />on water supplied to the AFV's in the area will continue until the mine workings <br />have filled to an equilibrium level. Given the past inflow rates encountered during <br />mining, equilibrium will be obtained within a short time. Therefore, the impact on <br />water supplied to the FF Tributary and Upper Curtis Creek AVF's will be minimal. <br />While active, Northern No. 1 pumped water from the mine to the sediment pond <br />located at the surface facility on the FF Tributary. The daily pumpage rate was <br />averaged by the applicant at .018 cfs. The waters pumped from the mine had total <br />dissolved solids (T'DS) averaging 1250 mg/1 and sodium absorption ratio (SAR) <br />values ranging from 45 while inactive to 64 while active. The baseline conditions in <br />the natural drainage show the surface waters carrying high TDS levels ranging from <br />13 <br />