2010-08-04_INSPECTION - C1981019

• Permit No: C1981019
• IBM Index Class Name: INSPECTION
• Doc Date: 8/4/2010
• Doc Name: Inspection Report
• Inspection Date: 7/19/2010
• Email Name: JRS
• Email Name: SB1
• Media Type: D
• Archive: No

July 19, 2010 C-1981-019/Colowyo Coal Mine JRS
- The backfilling and grading work completed in the West Pit will require Colowyo to construct the Taylor
Tributary Ditch to approximately station 45+00, the Taylor Ditch in its entirety (from station 0+00 to station
15+00) and the East Taylor Ditch to approximately station 40+00. The approved location of these ditches is
shown on Map 41.
- Colowyo has backfilled and regraded two additional small areas in 2010 that are not shown on Map 29. The first
area is the old R3 coal stockpile area, which is approximately 9 acres. The second area is a small wedge area
between the East Pit and Haul Road A, which is approximately 17 acres. Colowyo is reminded that these areas
will need to have the topsoil replaced and will need to be reseeded in 2010.
- Colowyo has not completed any backfilling and grading in the East Pit in 2010. Colowyo is scheduled to
complete approximately 36.5 acres of backfilling and grading in the East Pit in 2010. This backfilling and grading
will include the completion of the Prospect Ditch (from approximately station 15+00 to approximately station
22+00) and construction of the portion of the North Tributary, East Pit Ditch that lies in the 2010 East Pit
reclamation block. The approved location of these channels is shown on Map 41. (Based on an overlay of Map
41 and Map 29 there may be a very small 50-100 foot portion of the North tributary, East Pit Ditch that lies in the
2011 reclamation block.)
- Colowyo will need to perform overburden monitoring at all regraded locations in 2010 per the "Overburden
Monitoring Plan", which is detailed on page 2.05-3 in Permit Section 2.05.3.
EXCESS SPOIL and DEVELOPMENT WASTE - Rule 4.09 Placement; Drainage Control; Surface Stabilization:
-Colowyo is currently using the A-A'and B-B' underdrain areas of the West Taylor Fill to dispose of spoil
material at this time. The material is coming from the box-cut of the South Taylor Pit. Colowyo is working on the
first lift of the A-A' underdrain area.
- A small amount of water was flowing out of both the A-A' and B-B' underdrains of the West Taylor Fill. This
water was flowing into the West Taylor Pond.
- Colowyo was not placing any material on either the C-C' underdrain area of the East Taylor Fill or the final cut
area of the Section 16 Pit at the time of the inspection. It was indicated that spoil placement in the final cut of the
Section 16 Pit area has been completed.
HYDROLOGIC BALANCE - Rule 4.05 Drainage Control 4.05.1, 4.05.2, 4.05.3; Siltation Structures 4.05.5,
4.05.6; Discharge Structures 4.05.7, 4.05.10; Diversions 4.05.4; Effluent Limits 4.05.2; Ground Water
Monitoring 4.05.13; Surface Water Monitoring 4.05.13; Drainage - Acid and Toxic Materials 4.05.8;
Impoundments 4.05.6, 4.05.9; Stream Buffer Zones 4.05.18:
- The Streeter Pond (NPDES 001 A) contained water and was discharging through the weep hole at the time of the
inspection. The discharge looked clean. The electric conductivity was 2,800 umhos/cm and the pH was 7.4. The
pond embankment was well vegetated and stable and no erosional problems were noted.
- The Gulch A Pond (NPDES 004A) was dry at the time of the inspection. The pond embankment was well
vegetated and stable and no erosional problems were noted. Colowyo is planning on cleaning the Gulch A Pond
this summer but there is no date set.
- The Prospect Pond (NPDES 007A) contained water approximately six feet below the top of the riser pipe and
just below the weep hole and was not discharging at the time of the inspection. There was a small amount of
sediment at the pond inlet and water was flowing into the pond. The pond embankment was well vegetated and no
erosional problems were noted.
Number of Partial Inspection this Fiscal Year: 1
Number of Complete Inspections this Fiscal Year: 0
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