2016-01-22_REVISION - C1981014 ‎(4)‎

• Permit No: C1981014
• IBM Index Class Name: Revision
• Doc Date: 1/22/2016
• Doc Name: Adequacy Response #3
• From: Gorham Energy Consultants, LLC
• To: DRMS
• Type & Sequence: SL3
• Email Name: RDZ
• Email Name: JRS
• Media Type: D
• Archive: No

Sediment Demonstration — Mine Site - revised 1/22/2016 w/ 1/8/2016 addendum Page 5
Section 3.03.1
A = (24.7) (.32) (3.14) (.017) (1.0)
A = .422
The reclaimed condition produces less sediment than the non -mined condition. A summary of the
results is shown on Table 2.
Table 2
Mine site and RDA Annual Sediment Yield
tons/acre/year
Non -mined Condition .648
Reclaimed Condition .422
Addendum (1/8/2016 and as revised 1 /21 /2016)
As a result of the DRMS adequacy review of SL -03 (1/8/2016) EFCI has provided additional
information and supporting analysis specific to the LS factor and the sediment demonstration for the
mine site.
DRMS concern:
Regarding EFCI's explanation as to why the LS factors for the reclaimed areas and the
non -mined areas are identical, the Division still believes that is best to assess the LS
parameter separately: the post -mining condition should be based on the current
topography of the areas where bond release is sought, whereas the pre -mining condition
should be based on the pre -mining topography of the actual location of the RDA and
facilities area or on the topography of adjacent unmined areas. Also, Map 13 and 29 are
referenced in the sediment demonstration for the mine site: however, these maps are
related to the loadout. Please correct this error.
EFCI response:
EFCI used Map 33 to determine the LS factors for the sediment demonstrations. The text has been
corrected in the previous section. (1/21/2016 addendum) The LS factors for the mine site were
modified to better represent immediate conditions in and around the mine portal area and the RDA
when combined as one area. For the unmined condition, the LS factor consists of
EFCI has re-evaluated the sediment demonstration specific to the RDA and the surrounding area.
Two additional demonstrations were conducted. Demonstration #1 uses LS factors calculated from
the gently sloping terrain of the pre mine RDA footprint for the pre -mine condition, the topography
for which is readily implied by interpolating contour lines taken from Map 33, and uses actual length
and slope information from the reclaimed RDA for the post -mining condition. Average cover
values from 2013 and 2014 were used from the RDA reference area sampling and from the reclaimed
RDA sampling respectively.
LS factors for the two additional demonstrations are shown below.
Demo #1 RDA footprint only