2018-07-09_REVISION - C1982056 ‎(3)‎

• Permit No: C1982056
• IBM Index Class Name: Revision
• Doc Date: 7/9/2018
• Doc Name: Adequacy Review Response #2
• From: Twentymile Coal, LLC
• To: DRMS
• Type & Sequence: RN7
• Email Name: TNL
• Media Type: D
• Archive: No

Response: - The title for Exhibit 8Q has been revised to more accurately reflect its contents. Copies of the
revised exhibit slip -sheet and Table of Contents page accompany these responses for replacement in the PAP.
44. The 6MN Mine Water Storage Reservoir design information (Exhibit 8CC) is not called out in the Table of
Contents. Also, DRMS was not able to locate cross-section drawings of the reservoir. Please address the
following.-
a.
ollowing:a. Please update the Table of Contents to include Exhibit 8CC and submit the updated document to
DRMS.
b. Please either.-
i.
ither:i. indicate where in the permit, cross-section drawings are located for the 6MN reservoir or,
ii. submit cross-section drawings to DRMS.
c. Please inform DRMS if cross-section drawings exist for Area I Pit Temporary Water Storage Basin;
and if they exist where in the permit they are located.
d. If there are no cross-section drawings for Area 1 Pit currently in the permit please submit drawings
to DRMS.
e. Also, please make sore all design information in the permit pertaining to rule 2.05.3(4) reflects the
most recent updates and changes to all ponds, impoundments, diversions and treatment facilities and
associated spillways and culverts.
f. Please submit to DRMS any updated design, as built drawings and SedCad results that pertain to
bringing Section 2.05.3 up to date to accurately reflect the infrastructure that is "on the ground" at
Foidel.
Response: - The 6MN Mine Water Storage Reservoir was approved under TR07-61. The TR submittal included
revised TOC pages, including page vi, which shows Exhibit 8CC (copies attached). Design drawings for the
6MN Reservoir are included in Exhibit 490. The Area 1 Temporary Water Storage Basin is part of the last open
cut remaining from the previous surface mining activities, and was originally used as a storage area for low -
quality coal, prior to construction of the original Foidel Creek Mine Coal Preparation Plant. With construction of
the original Coal Preparation Plant in 1995, the low -quality coal was removed and processed, and the Area 1 Pit
was converted to a temporary water storage basin to support mine and plant operations. The Area 1 Pit was
designated and approved as a mine impoundment under TR05-47. Design documentation for the Area 1 Pit is
provided in Exhibit 8v, including the drawing and stage -storage curves for this impoundment (Figure EX8V-1).
For any drainage structure that has been modified, a revision including revised design information was submitted
and approved, as summarized in the response to Comment 37.
TA2 — It was unclear in the response received how Peabody addressed portions e and f of adequacy question 44.
As previously requested, please address the following;
e. Also, please make sure all design information in the permit pertaining to Rule 2.05.3(4) reflects the
most recent updates and changes to all ponds, impoundments, diversions and treatment facilities and
associated spillways and culverts.
f. Please submit to DRMS any updated design, as built drawings and SedCad results that pertain to
bringing Section 2.05.3 up to date to accurately reflect the infrastructure that is "on the ground" at
Foidel.
Response: - Please refer to the original response to Comment 39. In general, the designs for all ponds,
impoundments, ditches and diversions, treatment facilities, and associated culverts which were transferred from
the Energy Fuels Eckman Park Mines and Mines 1, 2, and 3 (Permit C-1981-071) to the Foidel Creek Mine
Permit (C-1982-056), were permitted under the Interim Program Regulations (prior to approval of the Colorado
Program) have not been modified, and are "grandfathered -in", so the existing design information is considered
adequate.
For any of the drainage structures noted above which have been modified, and any newly permitted and
constructed drainage structures, design information consistent with the applicable Colorado Mined Land
Reclamation Program Regulations (Rule 2.05.3(4)) has been provided in subsequent permit revisions and is
included in the PAP, as follows: