2016-01-26_REVISION - C1981014 ‎(2)‎

• Permit No: C1981014
• IBM Index Class Name: Revision
• Doc Date: 1/26/2016
• Doc Name: Sediment Resources
• From: W.D. Corley
• To: DRMS
• Type & Sequence: SL3
• Email Name: RDZ
• Email Name: JRS
• Media Type: D
• Archive: No

1/27/2016 State.co.us Executive Branch Mail-Fwd:Sediment sources
STATE, OF Hernandez - DNR Alysha <[e-mail]>
� �O L,O R�'Al u '
Fwd: Sediment sources
1 message
Zuber- DNR, Rob <[e-mail]> Tue, Jan 26, 2016 at 4:50 PM
To: Alysha Hernandez - DNR <[e-mail]>
Please file under Southfield SL-03.
Rob Zuber, P.E.
Environmental Protection Specialist II
Coal Regulatory Program
COILO RA DO
Division of Reclarn,afion,
A17 bfining and Safety
Department of Natural Resources
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303.866.3567, extension 8113 1 F 303.832.8106
1313 Sherman Street, Room 215, Denver, CO 80203
[e-mail] I http://mining.state.co.us
---------- Forwarded message ----------
From: W D Corley, Jr. <[e-mail]>
Date: Tue, Jan 26, 2016 at 12:27 PM
Subject: Sediment sources
To: Rob Zuber- DNR <[e-mail]>, Allen Weaver<alweaverefci@gmailocom>
Rob and Al,
It is impossible for me to to review any of the sediment models with the inconsistencies in the report and the
revision. My understanding of the purpose of the sediment model is to demonstrate that a reclaimed area will
not produce more sediment runoff than that area produced premining. It appears that the sediment models so
far are being manipulated to produce a certain favorable value instead of an unbiased scientific result. For
example, when premining footprint grades and the actual steep slope reclamation grades are used for the RDA
Demo #1, the resulting A difference is considered too high and other models are introduced to yield more
desirable results. But doesn't the Demo #1 represent the best fit of the comparison of the premining and
postreclamation topography?
However, whether the sediment models are predictive and useful or are unreliable and useless, the amount of
sediment being deposited in Pond 5 can be measured. According to George Patterson Pond 5 did not have to
be cleaned out after the initial seeding of the facilities area until 2011. Then in the last five years it had to be
cleaned out twice, and two of those last five years were far below average rainfall. The amount of sediment
measured in Pond 5 that was deposited between 2011 and 2016 is in excess of what is predicted by any of the
sediment models. Since the reclaimed grass revegetation is good there must be other sources for this excess
sediment runoff. Looking for these possible sources at least five have been identified.
1. The rill forming west of the truck tunnel has exhibited head cutting despite the rock check dams that have
been installed. This rill has progressed upstream behind the last rock check dam as noted in routine monthly
inspection reports that directed EFCI to perform additional repairs.
2. The road cut for the RDA haul road has large bare walls of shale at the lower end (attachment 1) and granite
alluvium and rocks near the upper end (attachment 2).
3. County Road 92 has been widened by EFCI with regrading and water bars leaving far more bare and
uncompacted road surface than premining. One place on this road at 38d17'12.26"N 105d09'11.81"W has been
widened to an unnecessary width of 38 ft.
4. The fresh water pipeline corridor has a large bare area near the top of the steep slope and a large head
https://mail.googl e.com/m ai I/u/0/?ui=2&i k=e29129fcb5&view=pt&search=i nbox&th=152805926ed62a53&si m l=152805926ed62a53 1/3