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Environmental Protection Plan, Schwartzwalder Mine 4-2 <br />. (e) Air Quality Permits <br />Two air permits are currently active: (1) 97JE0037F and (2) 85MO184-2P. <br />(if) Storm Water Discharge Permit <br />The Colorado stormwater discharge permit #COR-040046 has been in effect since March 19, 1993. The <br />stormwater management plan (updated in May of 2010) identifies potential sources of pollution (including <br />sediment) which may reasonably be expected to affect the quality of stormwater discharges associated with <br />the mine and describes the best management practices (BMPs) used to reduce pollutants in stormwater <br />discharge. <br />(g) Well Permit <br />Water Resource Permit Number 64684, issued September 22, 1972, by the Office of the State Engineer for <br />the non-industrial domestic water well. <br />No other air, water quality, or solid and hazardous waste permits are in effect for the reclaimed <br />Schwartzwalder Mine. The Schwartwalder does not currently use, handle, store, or disposal of designated <br />chemicals. No acid mine drainage-forming materials have been handled or stored within the permit area3. <br />Additional permits may be required in the future, related to mitigation options under consideration for <br />groundwater in the alluvium and fill material (Section 15). <br />• <br />3 All geochemical testing performed on materials from the site indicates that mine rock is classified as having a very low potential <br />to produce acid and a high potential for neutralizing acid. Specifically, the results of the acid-base accounting (ABA) tests <br />indicate that waste rock from the Schwartzwalder Mine is strongly neutralizing with an average net neutralizing (NNP) capacity <br />of 149 t CaC03/kt and an ANP/AGP ratio of 10. The mined rock has a very low potential to generate acidic drainage, and no <br />acidic drainage has been detected from the mine or waste rock facilities to date. <br />Of the five seeps and drips described in Section 9(b)(iv).3, two had low pH (WASH [3.8], ILLRS [2.71) and three had near <br />neutral to slightly basic pH (Minnesota [7.9], CO [7.9], and 146 [8.2]). The two seeps with the lowest pH values had the lowest <br />flow rates, measured at 0.03 - 0.05 gpm for the WASH and 0.15 gpm for the ILLRS. Two of the seeps with the highest pH had <br />the highest flow rates, measured at 0.8 gpm for the CO and 0.5 gpm for the 146. Therefore, the two low-pH drips were <br />measured at a combined flow rate of less than 0.2 gpm compared to the 1.3 gpm measured at neutral to basic seeps and the <br />unmeasured flow of neutral pH waters near the Minnesota Glory Hole. <br />Overall, the seeps and drips from the unsaturated zone above the mine represent a small quantity of flow through native, in-situ <br />(non-handled) rock materials. Despite these small drips, the pH of the mine pool remains circum-neutral, with no indication that <br />the mine pool will go acid. Bicarbonate alkalinity exceeds 400 mg/L (as CaCOO, which indicates significant buffering capacity <br />within the mine pool. No trends of decreasing pH or alkalinity have been observed to date in mine pool water (Section <br />9(b)(iv).2). The small seeps and drips from the unsaturated workings above the Steve Level contribute significantly less than <br />one gallon per minute annually to the 139 million gallon mine pool, and the alkalinity in the mine pool is sufficient to buffer this <br />small contribution. <br />4109C.100731 WiietstoneAssociates