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well as water from two long term spoil springs. These springs are sampled and regulated <br /> through the PSCM NPDES permit. Pond 004, a permanent Phase III released pond <br /> discharges into the stream channel in the Fish Creek AVE Pond The runoff and <br /> leachate can be expected to be alkaline, with the chemical constituents of greatest <br /> concern being dissolved solids, mainly salts of sulfate. PSCM proposes no new <br /> disturbances or discharges in the Little Grassy Creek AVF; therefore, there is no <br /> potential for material damage to this AVE <br /> No changes are proposed for the Pond 004 watershed during PSCM mining; therefore, <br /> the Division's evaluation of that watershed as described in the findings document for <br /> the Seneca II Mine is applicable to the PSCM mine. Pond 004 was part of the approved <br /> SL4 Phase III bond release. Table 2.05.6(3)-T1 of PSCM permit application contains a <br /> mass balance analysis that indicates that mixing of discharges from PSCM ponds with <br /> stream waters will result in maximum TDS of 3,259 mg/l in the channel of the Grassy <br /> Creek AVE Although 3,259 mg/l equates to 4,345 mmhos/cm, a value well above the <br /> 1,000 mmhos/cm material damage threshold, the high TDS is a result of Seneca II <br /> surface mining activities that, as previously explained, are exempt from AVF material <br /> damage rules 3.06.8(5)(a)(i) and(ii). Based on the limited effects of PSCM discharges <br /> from underground mining activities on surface water quality in the Fish Creek, Grassy <br /> Creek, and Little Grassy Creek AVFs, alluvial ground water quality should not be <br /> significantly impaired. Subirrigation is expected to be less affected by mine discharge <br /> than by irrigation using surface waters. A conservative estimate of the expected effect <br /> of mining indicates that no material damage will result. <br /> In addition to water quality degradation, another type of material damage that can occur <br /> to an AVF is physical disruption of the AVF's capability for irrigation or subirrigation <br /> (the AVF's essential hydrologic function). PSCM does not propose excavations in the <br /> Fish Creek, Grassy Creek, or Little Grassy Creek AVFs; therefore, the essential <br /> hydrologic functions of these AVFs will not be physically disrupted. PSCM will <br /> monitor discharges to the Grassy Creek and Little Grassy Creek AVFs at pond 002 and <br /> will monitor discharges to the Fish Creek AVF at pond 004 through their NPDES <br /> permit, though this pond is longer regulated by the Division. PSCM will monitor <br /> alluvial ground water in the Grassy Creek AVF in well YSG5 and in the Little Grassy <br /> Creek AVF in well SGAL71. PSCM will monitor surface water in the Fish Creek AVF <br /> at SSC 10. <br /> The Division finds that activities proposed by the applicant will not interrupt, <br /> discontinue, or preclude farming on the alluvial valley floors that are irrigated or <br /> naturally subirrigated (4.24.3(1)). <br /> The proposed activities will not materially damage the quantity or quality of water in <br /> the surface or ground water system described above (4.24.3(3) and 2.06.8(5)(a)(ii)). <br /> The proposed activities will comply with the requirements of the Act and the <br /> Regulations with respect to alluvial valley floors. (2.06.8 (5)(a)(iii)). <br /> 24 <br />