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2.05.6(6) <br />The mine expansion to the north (PR -14) encompasses Federal Coal Lease <br />COC -75916. There are six (6) ponds, three (3) springs with ponds or tanks, <br />and four (4) springs within the federal coal lease. All thirteen (13) of the <br />hydrologic features have overburden in excess of 800 feet. <br />A limited extraction zone is proposed for Pond P-1 and P8-4 because they <br />both are located in a zone of greatest subsidence impact. <br />A limited extraction zone was established along the bleeder entries in the <br />vicinity of Freeman Gulch and the vent shaft in Freeman Gulch. This limited <br />extraction zone was established to assure subsidence does not affect the <br />stability of adjacent old landslides to the extent their deformations were <br />renewed. <br />Portions of Terror Creek, Hubbard Creek, Hubbard Creek road and Terror <br />Creek road are located in zones of intermediate and greatest subsidence <br />impact. For this reason, these areas will be protected by a limited <br />extraction zone. The limited extraction zone is defined by extending a <br />safety zone a distance of one hundred feet from the creek then projecting <br />a line down at the 250angle of draw to the coal seam. <br />Regarding the Bruce Park Dams, the GEI Consultants Inc. report referenced <br />above concluded the main dam and saddle dam would be stable under the <br />assumed seismic loadings and mine workings within 1300 feet of the dam(s). <br />Experience at the Bowie No. 1 Mine supports the position that springs and <br />ponds will not be damaged by the effects of subsidence. Under similar <br />geologic conditions, the Bowie No. 1 Mine mined under numerous springs <br />and ponds with no reported detrimental effect on any of the resources. <br />During the period from 1980 through 1997, as presented on the following <br />table, a total of 12 springs and 28 ponds were undermined. Six springs and <br />six ponds were undermined at depths of less than 800 feet of overburden. <br />Yet there was no detrimental effect on any of the springs or ponds. <br />PR -14 2.05-160- 03/14 <br />