My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
2008-09-19_GENERAL DOCUMENTS - C1981018
DRMS
>
Day Forward
>
General Documents
>
Coal
>
C1981018
>
2008-09-19_GENERAL DOCUMENTS - C1981018
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
8/24/2016 3:36:25 PM
Creation date
9/22/2008 1:14:12 PM
Metadata
Fields
Template:
DRMS Permit Index
Permit No
C1981018
IBM Index Class Name
GENERAL DOCUMENTS
Doc Date
9/19/2008
Doc Name
Proposed Decision & Findings of Compliance for PR6
From
Add 760 Acres
Permit Index Doc Type
Findings
Email Name
JDM
Media Type
D
Archive
No
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
33
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
subsidence with possible development of tension cracks on the surface due to <br />differential settling. Observed ground water inflows during mining have <br />been approximately 50 gpm. In fractured areas, increased flows of 100 to <br />300 gpm may be encountered for a short period of time. These flows will <br />diminish as equilibrium is reestablished. Due to the low transmissivities of <br />the aquifers, if caving should create a hydrologic connection from the mine to <br />an aquifer within 30 to 40 feet of the coal, the additional inflow will be <br />minimal. It is not probable that fracturing from the mine to the surface will <br />occur as a result of subsidence and cause the flow of surface water to the <br />mine. <br />Subsequent to completion of mining, the ground water will slowly reestablish <br />its pre-mining water levels. Due to caving of the roof materials into the <br />mine, an area of increased permeability will exist within the mine that will <br />act as a "sump area" until equilibrium is established. However, due to the <br />small quantity of water in the aquifers being discharged to the White River <br />and its tributaries, the lack of ground water usage in the area, and the poor <br />quality of ground water, potential impacts to flow in the White River will be <br />minimal. <br />The possibility exists for water to discharge from the portals once the mine <br />workings have become completely flooded. The portals are up-dip in the <br />mine, and drainage will tend to move down dip of the mine and coal seam, <br />thereby increasing the time to flood the mine workings. The permittee has <br />proposed backfilling of the portals and construction of bulkheads upon <br />closure of the mine, minimizing the possibility for discharge. <br />A large coal refuse disposal area exists in the northern section of the mine <br />permit area. Drill hole data indicate that there is no ground water within 44 <br />feet of the ground surface in the coal refuse disposal area, and recharge to <br />ground water in the Mesaverde Group is minimal. Infiltration of water <br />through the refuse piles will be minimized by covering the compacted refuse <br />with 30 to 48 inches of the best available nontoxic material. Impacts to the <br />ground water system are not expected to be significant due to the relatively <br />impermeable nature of the refuse and the low water table. <br />In summary, the impact of the proposed mine on ground water will be <br />localized, with no significant impacts expected on a regional basis, due <br />primarily to the small quantity of ground water in the area. <br />No significant cumulative hydrologic impacts are expected as a result of the <br />mining activities at Deserado Mine. The Division finds, in accordance with <br />C.R.S 34-33-114(2)(c) and Rule 2.07.6(2)(c), that the operation has been <br />designed to prevent material damage outside the permit area. <br />Deserado Mine 24 September 19, 2008
The URL can be used to link to this page
Your browser does not support the video tag.