REP50641

• Permit No: C1981019
• IBM Index Class Name: Report
• Doc Date: 9/28/2005
• Doc Name: 3rd Quarter 2005 West Pit Fill Inspection Report and Certification
• From: Knight Piesold and Co
• To: DMG
• Permit Index Doc Type: Waste Pile/Fill Report
• Media Type: D
• Archive: No

Knight Piesold
CONSULT 1 N O
September 28, 2005
For: File
Knight Piesold and Co.
1050 Seventeenth Street, Suite 450
Denver, Colorado 80265-2011
U.S.A.
Telephane(303) 629-8788
Te[efax [phone]
Re. Colowyo Coal Company L.P. (0-81-019) YOUR REFERENCE
West Plt Flll II1SpeetlOn Report and CertlflcatlOn OUR REFERENCE
Third Quarter, 2005
West Pit Fill Inspection Certification
On September 21, 2005, I inspected the area in which the West Pit Excess Spoil Fill is being
constructed. The purpose of this inspection was to observe the surface rock drain that borders the
3:1 Excess Fill Slope; inspect the areas dumped to final grade below the 7,400 dump elevation;
inspect the revegetation on the fill surface and inspect the fill for areas of water seepage or surface
drainage; inspect the final grade slopes below the 7,300 elevation of the Excess Fill Slope; and
satisfy the requirements of CDMG Rule 4.09.1(1 la) and Rule 4.09.1 (1lb).
During the inspection, it was observed that the condition of the fill was good and that no seeps or
springs were noted. The collection ditches at the 6,950, 7,050, and 7,150 elevations all were in
relatively good shape. The ditch at the 7,250 elevation needs to be completed to the west end of the
fill. No water was evident in the surface drain or underdrains.
In addition, I reviewed the monument survey data. These data indicate that the elevations of most
of the monuments have not significantly changed (less than 0.1 feet of movement) with the most
movement noted in the 7,250 east monument (0.07 feet). Based on these data, the total displacement
of the monuments is not of concern with regard to the stability of the dump. There was also no
evidence of structural weakness or other hazardous conditions associated with this dump. These
monument survey data are available for review upon request at the Colowyo Mine site.
I am a Registered Professional Engineer in the State of Colorado and a representative of Knight
Piesold and Co., 1050 Seventeenth Street, Suite 450, Denver, Colorado 80265-2011. Being familiar
with the Colowyo operation and the coal program permitting process in Colorado, the construction
activities related to the West Pit Excess Spoil Fill are in conformance, to the best of my knowledge
and experience, as specified in pages la-2 through la-4, Exhibit 191b and other applicable
requirements of the approved permit documents, a portion of CDMG Permit C-81-019.
xc: Mr. Kurtis Blunt, Colowyo Coal Company, L.P.
cf 17.15.1 2005