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Pagel of 2 <br />Hernandez, Daniel <br />From: Hernandez, Daniel <br />Sent: Tuesday, February 17, 2009 11:49 AM <br />To: Binns, Janet; Kaldenbach, Tom <br />Subject: Eagle 5&9 SL2 <br />Hi, guys - <br />Regarding Dave Berry's 2/9/09 e-mail to us pertaining to his review of Tom's sections of the Eagle 5&9 SL2 <br />Findings Document regarding hydrology and subsidence, I spoke with Jerry Nettleton today and told him of <br />Dave's concerns. I told Jerry that Dave had two concerns with Tom's write-up. <br />The first was that Dave felt that Tom's write-up "seems to acknowledge on-going water management", indicating a <br />concern on Dave's part that a hydraulic connection exists between the mine's western underground workings <br />(those that underlie the area being requested for release) and the eastern workings (where dewatering is actively <br />occurring). <br />The second was that Dave felt that Tom's write up seemed to suggest that subsidence damage had not occurred <br />in the areas overlying the underground workings, which Dave believed was contrary to what he remembered as <br />some subsidence damage actually having occurred (and having been repaired) in surface lands overlying the <br />workings being requested for release. <br />Regarding the first bullet, Jerry informed me that several years ago, Empire had installed seals in the <br />underground entries that accessed the east side of the mine from the west side (the west side is the area being <br />requested for release). According to Jerry, these seals were installed soon after the 5A portals were constructed <br />over at the east side of the mine. Jerry said that he believes the seals hydraulically separate the western <br />workings from the eastern workings. <br />Jerry stated that, in addition, he thought that Empire had responded to our concerns regarding the hydraulic <br />communication issue by submitting a geologic cross-section that Empire had prepared that demonstrated that <br />water from the western workings wouldn't reach the seals due to (1) the western workings being lower in elevation <br />than the eastern workings, and (2) geologic structural features (anticlines, faults) keeping the water physically <br />away from the seals. Jerry said he thought (though he said he wasn't sure) that Empire had also made the case <br />that any water that started to fill the western workings would not reach the seals because the water would seep <br />out of the mine into the Yampa and Williams Fork Rivers via geologic pathways (through coal seams, through <br />bedding planes, and through faults). I asked Jerry if he remembered whether Empire had made the case that this <br />seepage/discharge rate into the rivers was equal to or greater than the mine inflow rate (which would indicate that <br />the direction of flow would be from the mine to the rivers, rather than the other way around). He said he wasn't <br />sure. <br />So - Where do we go from here? <br />Regarding the first issue, please check the SL2 files for a map indicating the locations of the underground seals, <br />and a geologic cross-section (and any accompanying correspondence) that may have been submitted by Empire <br />to address our concerns regarding hydraulic communication between the eastern and western workings. While <br />the map may have been submitted at the time the release request was submitted (9/17/04), Dave indicated in his <br />2/9/09 e-mail that I wrote a letter to the company dated March 1 2005.regarding the hydrologic communication <br />issue; therefore, also look in the files for information that may have been submitted after 3/1/05. <br />Regarding the second issue, a listing of all subsidence damage identified during our bond release inspections, as <br />well as the repairs conducted to that damage, needs to be prepared for inclusion in the Findings Document. If <br />there is any subsidence damage that we documented during our past inspections that has not yet been repaired, <br />we would need to ask the company to repair that damage (any unfilled holes in any two-track roads for example) <br />and verify that the work was done, or discuss with Dave why we think that damage would not need to be repaired <br />(such as cracks in rocks). Any subsidence damage that Dave believes needs repairing that has not yet been <br />repaired would need to be fixed and verified before we could approve the release request. Ultimately, the <br />3/11/2009