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The existence of the mine workings will permanently modify the <br />pattern of ground water flow. The flooded mine constitutes a <br />region of essentially infinite permeability that will tend to <br />cause ground water to preferentially pass through the <br />workings. The water passing through the flooded mine may be <br />degraded in quality, relative to that in the undisturbed <br />strata. <br />Another potential ground water impact is due to subsidence and <br />the fracture-related drainage of surface water bodies into the <br />subsided areas. These surface water bodies would be the mine <br />water ponds, ephemeral drainages, and the perennial Newlin <br />Creek. Dewatering of the ponds would short-circuit the water <br />system during mining, which is not considered a significant <br />impact. Also, the effects to ephemeral drainages would be <br />minimal. However, diversion of stream flow from Newlin Creek <br />to the underground workings may be significant. The <br />interception of surface water or shallow ground water by <br />underground workings presents a potential impact to water <br />availability in Newlin Creek. However, as previously <br />mentioned, Newlin Creek's surface flow is diverted upstream <br />via a pipeline owned and operated by the City of Florence. <br />This reduces the significance of any depletion of the creek <br />from mining. <br />The mine is presently incurring water sources in both the <br />north and south sections of the mine. Quantification of total <br />depletions to Newlin Creek are nearly impossible to make, <br />since mining adjacent to this creek was primarily conducted <br />from 1900 through the 1970's. Most of these areas have been <br />sealed off and, therefore, could not indicate reliable <br />inflows. However, the mine inflow study being conducted by <br />the operator will provide valuable data on impacts from the <br />Southfield operation. The primary source of water entering <br />the mine appears to be abandoned workings nearby and above the <br />mine. Quantities of mine inflows have decreased from around <br />40 acre-feet in 1995-1997, to 10-15 acre-feet in 1998-2000. <br />According to the EFCI, this decrease is most likely due to the <br />mine reaching an equilibrium with the surrounding groundwater <br />system such that water no longer rises into the accessible <br />area of the mine. <br />Southfield Mine Permit Renewal 03 <br />43 <br />