My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
2014-10-15_PERMIT FILE - C1982056A (7)
DRMS
>
Day Forward
>
Permit File
>
Coal
>
C1982056A
>
2014-10-15_PERMIT FILE - C1982056A (7)
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
8/24/2016 5:48:54 PM
Creation date
10/28/2014 11:00:31 AM
Metadata
Fields
Template:
DRMS Permit Index
Permit No
C1982056A
IBM Index Class Name
Permit File
Doc Date
10/15/2014
Doc Name
Pages 2.05-65 to 2.05-197.3 part 2
Section_Exhibit Name
2.05 Operation and Reclamation Plans Part 2
Media Type
D
Archive
Yes
Jump to thumbnail
< previous set
next set >
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
220
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
View images
View plain text
With both Washplants I and II operating, the thickener underflow is typically a 15 to 25 percent solids, 300 to 550 <br />gpm slurry mixture of rock and coal fines (28 mesh x 0). Exhibit 9C, Underflow Chemical Characterization, <br />provides data on selected chemical constituents found in the thickener underflow. The water quality of the slurry is <br />consistent with that of typical spoils water generated at the adjacent CYCC surface mine. The slurry mixture was <br />historically piped to the sealed mine workings in the EMD, where the fines would settle -out, and the decant water <br />would flow to a sump and be recycled back to the washplants. At the full coal fines refuse discharge rate, <br />approximately 1.6MM ft3 of coal fines storage is required on an annual basis. The EMD has approximately <br />110MM ft3 of coal fines storage capacity remaining (approximately 70 -years capacity). In anticipation of possible <br />future mining of the underlying Wolf Creek Coal Seam, TC shifted underground coal fines slurry placement to <br />sealed mine workings in the Southwest Mining District (SWMD), which provides approximately 61 MM ft3 of coal <br />fines storage capacity (approximately 30 -years capacity). Map 23 shows the EMD and SMD areas that have been, <br />or will be filled with fine refuse material. <br />With the addition of new thickener underflow boreholes at the 6RT, 7RT, and 2MN locations, it will be possible to <br />pump the fine coal refuse slurry from the washplants through either the 1MN or the 6RT /7RT pipelines to the <br />corresponding boreholes. The 1RT pipeline consists of two 6 -inch HDPE pipelines extending approximately 1,800 <br />feet to an 8 -inch cased mine borehole, located near the former CYCC Mine Office Building ( "Brown Palace ", see <br />Map 24 for location of pipeline and borehole). The two Thickener Underflow Pipelines replace the previously used <br />6 -inch PVC line from Washplant I, which was cut -off, capped, and abandoned in- place. The 6RT /7RT /2MN <br />pipeline will be a double HDPE pipe system in critical areas, with a 6.625 -inch carrier pipe inside a larger <br />(maximum size - 12 -inch diameter) containment pipe, extending approximately 9,600 feet to 7RT. Electronic <br />moisture sensors, along with pump controls, and shut -off valves will provide for timely detection, shut -off, and <br />isolation of the pipeline in the event of pipeline leakage. Access /inspection manholes will be located at key points <br />along the pipeline routes. The pipelines will be buried at a depth of approximately 5 feet and traverse both <br />previously disturbed and un- disturbed areas. Installation of the two thickener underflow pipelines involved: <br />• Placement of temporary BMP's for drainage and sediment control for pipeline and borehole construction <br />areas <br />• Removal and windrowing or stockpiling of soils materials from any new disturbance areas <br />• Excavation of the pipeline trench, with temporary placement of excavated material adjacent to the trench <br />• Excavation of boring /jacking pits on the edge of Haulroad B -2 and an existing drainage ditch on the north <br />side of the existing railroad spur (as shown on Figure 49K -F1) and boring /jacking of 24 -inch secondary <br />containment culvert under existing Foidel Creek road crossing culverts and railroad spur <br />• Boring and casing of the thickener underflow boreholes <br />• Excavation of the pipeline trench, with temporary placement of excavated material adjacent to the trench <br />• Excavation of boring /jacking pits for underground pipeline crossings of Foidel Creek, RCR27, and the <br />railroad spur, or trenching of these areas <br />• Bedding and placement of the thickener underflow pipelines in the trench, and installation of intermediate <br />access manhole(s) <br />• Installation of moisture sensors, and connection of the pipelines to the thickener underflow systems from <br />the Washplant I and II Thickeners, along with associated pump controls and shut -off valves, and pressure <br />testing of the pipeline <br />• Controlled backfilling and compaction of excavated material in the trench <br />• Surface grading, soil material replacement, seeding with TCC's temporary stabilization seed mixture, and <br />placement of temporary BMPs to control runoff and erosion until vegetation was reestablished for all <br />project disturbance areas <br />The thickener underflow borehole surface casings extend approximately 4 feet above grade, and are capped and <br />locked. The borehole casing extends approximately 310 feet into sealed and abandoned mine workings in the <br />SWMD, and 510 feet into 6RT, 850 feet into 7RT, and 150 feet into 2MN, discharging on the mine floor, where the <br />fines settle -out and the decant drains to the decant sumps, where submersible pumps recycle the water back to the <br />surface. <br />MR13 -273 2.05 -97.7 12/06/13 <br />
The URL can be used to link to this page
Your browser does not support the video tag.