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2.05.6(6) <br />Ponds P -3 through P -6 are located in a zone of minor subsidence in an area <br />of overburden greater than 1,000 feet. Therefore, no limited extraction zone <br />will be provided for Ponds P -3, P -4, P -5 and P -6. <br />Five additional ponds are located within the permit boundary in zones of <br />minor subsidence. They are Pond 33 -3, Spring /Pond 33 -5, Pond 33 -7, <br />Spring /Pond 34 -2 and Spring /Pond 34 -11. Two ponds are located outside of <br />the permit boundary in zones of minor subsidence. They are Pond 32 -3 and <br />Spring /Pond 33 -6. Refer to Map 9, Hydrologic Location Map for location <br />information. <br />In the mine expansion area to the west there are forty (40) monitored springs <br />with ponds and ponds located within the permit boundary. See table at the <br />end of this section. There are three of the hydrologic features that have <br />overburden less than 800 feet. Pond 8 -4 has and overburden of 350'. Pond <br />17 -1 has an overburden of 450'. Spring 21 has an overburden of 475'. Pond <br />8 -4 and Spring 21 overly the south mains so they by default are located in a <br />limited extraction zone. Pond 17 -1 is near some of the old Bowie No. 1 mine <br />workings that are within the permit boundary. Because of its location, Pond <br />17 will not be undermined by the Bowie No. 2 mine workings. Therefore, the <br />three hydrologic features that have low overburden will not be affected by <br />subsidence. <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 />PR -13 2.05-148- 02/13 <br />