2007-11-16_GENERAL DOCUMENTS - C1981041 ‎(3)‎

• Permit No: C1981041
• IBM Index Class Name: General Documents
• Doc Date: 11/16/2007
• Doc Name: Proposed Decision & Findings of Compliance for RN5
• Permit Index Doc Type: Findings
• Media Type: D
• Archive: No

SECTION B
The following findings and specific approvals are required by Rule 4:
1. Roads - Rule 4.03
Information on roads is presented in Section 2.05.3, in Tab-13 of the permit application.
There are six haul roads, five access roads and five light-use roads within the permit area that
demonstrate compliance with applicable standards of Rule 4.03. All the roads meet the design criteria
for grade and surfacing. All were found to be in compliance. Two pipe arches which convey runoff
flow in Coal creek beneath Haul Road 4 near the Roadside North Portal have an end area of greater
than 35 square feet; therefore, to be in compliance with Rule 4.03.1(4)(e)(i), they must pass the
20-year, 24-hour peak flow. The permittee installed inlet transitions in order to pass the event.
Designs for proposed new Access Road 1 A were provided in PR-3 (see narrative on page 13-3i and
Table 13 page T13-2-6, location diagram on page A14-5-30, embankment stability analysis within
Appendix 14-8, and additional design and location information on Exhibits 6C, 6C-A, and 26).
Access Road IA will be constructed on Snowcap Coal Company property in association with
reclamation work necessary to implement the alternative "Industrial or Commercial" postmining land
use. The road will be located to the west of existing Access Road 1, and will provide access to the
mine bench repair shop, storage, and parking areas following completion of reclamation. The road
will be constructed in accordance with the design and construction criteria of Rule 4.03.2(3),
applicable to road segments that are not located within "disturbed areas", and will replace the segment
of Access Road 1 between the lower parking area and the mine bench. The segment of Access Road I
between the lower parking area and the mine bench will be reclaimed. Access Road 1 A and a short
upper segment of Access Road 1 (approximately 100 feet in length) will be retained for the alternative
postmining land use. The segment of Access Road 1 to be retained will provide access to proposed
equipment storage areas located on the flat top of the RSRDA waste disposal site.
Three dip-sections were installed along coal creek during construction of Haul Roads 2, 3 and 4. The
two upper dip-sections have six 36-inch CMP culverts laid side by side and incased in concrete. In the
concrete, they have an end area greater than 35 square feet, therefore, they must pass the 20-year,
24-hour peak flow to be in compliance with Rule 4.03.1(4)(e)(i). The lower dip section is only
required to pass the 10-year, 24-hour peak flow to be in compliance with Rule 4.03.1(4)(e)(i).
Designs reveal that the dip-sections will not pass the design peak flows without overtopping. In 1982,
the permittee submitted justification that the dip-sections would be as environmentally sound as
designs which would comply with Rule 4.03.1(4)(e)(i). Since the dip-sections are constructed of
reinforced concrete, they will not erode if overtopped. In addition, the upstream and downstream
sections of the stream are protected by riprap so they will not be undermined. The overtopping of the
dip-sections will likely be a gradual event. The water will flow over the top of the smooth concrete
surface with very little turbulence being induced by the dip-section. According to calculations done
by the permittee, the dip-sections would be overtopped for a total of 3.4 hours during a 20-year,
24-hour precipitation event. The installations are therefore acceptable to the Division.
Permit Renewal No. 5 20 November 16, 2007