My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
2011-06-23_REVISION - M1986002
DRMS
>
Day Forward
>
Revision
>
Minerals
>
M1986002
>
2011-06-23_REVISION - M1986002
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
6/15/2021 5:58:14 PM
Creation date
6/27/2011 1:58:37 PM
Metadata
Fields
Template:
DRMS Permit Index
Permit No
M1986002
IBM Index Class Name
REVISION
Doc Date
6/23/2011
Doc Name
Adequacy review CN-01
From
DRMS
To
Oldcastle SW Group, Inc.
Type & Sequence
CN1
Email Name
THM
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.
/
5
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
DIVISION OF RECLAMATION, MINING AND SAFETY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 866 -3567 <br />FAX: (303) 832 -8106 <br />Office of <br />Mined Land Reclamation <br />MEMORANDUM <br />STATE OF COLORADO <br />To: Travis Marshall <br />From: Tim Cazier, P.E. <br />Date: June 23, 2011 <br />Re: Craig Ranch Pit — General Stormwater Comments, Permit No. M- 1986 -002 / <br />CN -01 <br />COLORADO <br />DIVISION OF <br />RECLAMATION <br />MINING <br />SAFETY <br />John W. Hickenlooper <br />Governor <br />Mike King <br />Executive Director <br />Loretta Pineda <br />Director <br />The Division of Reclamation, Mining and Safety (Division) engineering staff has completed its <br />review of the stormwater management aspects of the subject project. <br />The Craig Ranch Pit is proposed in an area characterized by an arid environment with mild to <br />steep gradients sloping north towards the Gunnison River. The following comments are posed to <br />ensure adequate engineering analyses and design practices are implemented to eliminate or <br />reduce to the extent practical the disturbance to the hydrologic balance expected by the mining <br />operation with respect to water quality and quantity in accordance with Rules 3.1.6 and 6.3.3(g) <br />and (i) of the Minerals Rules and Regulations of the Colorado Mined Land Reclamation Board <br />for the Extraction of Construction Materials. <br />1. Page D -5, fourth paragraph: This paragraph describes collection ditches to be placed on <br />the northern most portion of the mining area and states these ditches will be placed "to <br />ensure that no stormwater is allowed to leave the site during mining " This statement <br />implies the collection ditches are designed to convey the probable maximum precipitation <br />(PMP) event. However, no sizing information is included in the exhibits. <br />a. The Applicant shall provide sufficient information (e.g., hydrologic analyses — see <br />Comment No. 10 and hydraulic computations — see Comment No. 11) for the <br />Division to evaluate the collector ditch sizing in accordance with Rule 6.3.3(g). <br />Please note because these ditches are to be part of the post mine land use, the <br />Division recommends they be sized to convey runoff from the 100 -year, 24 -hour <br />storm event, not the PMP. Also note Comment No. 5 below. <br />b. The applicant should revise the fourth paragraph on page D -5 to state what <br />specific design storm the collection ditches are designed to control. <br />2. Map C -2 is referenced on page D -5, fourth paragraph. The collection ditches in Mining <br />Area 1 appear to drain toward four ponds labeled as "Wash Ponds ". On Map F, the two <br />northern ponds are labeled "Sediment Ponds ". <br />Office of <br />Denver • Grand Junction • Durango Active and Inactive Mines <br />
The URL can be used to link to this page
Your browser does not support the video tag.