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-~ iiiiiiiiiiiiiiiiiii - <br />' 999 <br />Mountain Coal Company <br />West Elk Mine <br />Poet Office Box 591 <br />Somerset, Colorado 81434 <br />Telephone 303 929-5015 <br />Fax 303 929-5595 <br />November 10, 1993 <br />Ms. Christine E. Johnston <br />Colorado Division of Minerals and Geology <br />Office of Mined Land Reclamation <br />1313 Sherman St., Room 215 <br />Denver. CO 80203 <br />Re: West Elk Mine, Permit C-80-007, <br />TR 66, Refuse Pile Slump Repair <br />Deaz Christine: <br /> <br />NOV 12 lyy3 <br /> <br />i~ <br />Enclosed for your files is the affidavit of publication for the technical revision No. 66 public notice. In addition, <br />Mountain Coal Company (MCC) has reviewed your and Jim Pendleton's adequacy concerns per your letter of <br />November 01, 1993. Map 54 has been revised to include the french drain and new ditch D2R-2 and berm D2R-2 <br />locations. Instead of revising the existing Figure 2.0, "Reco~gtued Pile Contours" in Exhibit 51 (Figure 1.0 is no[ <br />appropriate to revise), please add the "Proposed Landslide Remediation" drawing as Figure 2.OA in this Exhibit. <br />MCC agrees [ha[ monitoring the stability of the gob fill buttress is appropriate and proposes to install survey <br />monuments (similar to [hose on the north face of the refine pile) at appropriate intervals from [he base as the fill <br />face is completed. Monitoring of these monuments will be conducted quarterly, along with the north face <br />monuments. <br />MCC does not propose to install a piezometer at this location, as we believe that the stability survey program is <br />sufficient to moniror [he success of the repair. To reiterate from the revision request, this installation is a shallow <br />gravel pack french drain (no[ an underdrain) to accumulate and divert the suficial spring }lows at the slump area <br />to the ditch below. Survey monitoring data from the spring site and the haul road located above have shown [hat <br />the slump area is shallow in nature, not deep-seated, so [hat the shallow drain is appropriate. The gob fill over the <br />drain is to buttress the slump area. Logically, if the spring or seep flows in the slump area continue, they will <br />follow the path of least resistance through the wide shallow drain. A gravel packed piezometer may in fact act as a <br />conduit for flows to the soils below the drain and up through the gob in which it is completed. MCC therefore <br />believes that a piezometer may further complicate this simple drain installation and does not propose to complete <br />such monitoring. <br />Please don'[ hesitate to contact me should you have further questions. <br />Sincerely, <br />// ~, ~Q,Q~f` <br />Kathleen G. Welt <br />Environmental Supervisor <br />KG W/mar <br />