2003-07-31_PERMIT FILE - M2003001

• Permit No: M2003001
• IBM Index Class Name: Permit File
• Doc Date: 7/31/2003
• Doc Name: Adequacy Review Response
• From: Hall-Irwin Corporation
• To: DMG
• Media Type: D
• Archive: No

-----Original Message-----
> From: Sorenson, Allen [mailto:allen.sorensonQState.co.us7
> Sent: Monday, July 21, 2003 5:45 PM
> To: '[e-mail]'
> Subject: slurry wall info
> Danna,
> This email addresses the issues we discussed on the phone in relation to
> the 20 percent bonding option described in the "Guide to Specification
> Preparation for Slurry Walls and Clay Liners as a Component of a
> Colorado Mined Land Reclamation Permit," Division of Minerals and
> Geology, September, 2000.
> You described a project under consideration where a slurry wall will be
> installed prior to the commencement of mining. The design,
> specifications, and quality assurance documents will not be included in
> the reclamation permit application, but will be prepared and submitted
> as a technical revision, and the revision will be approved prior to
> initiation of slurry wall construction. Construction of the slurry wall
> will be conducted under an approved Temporary Substitute Supply Plan
> (TSSP) that will account for evaporative loss of water exposed in slurry
> trenches and the consumption of the water entrained in the gravel to be
> surrounded by the slurry wall.
> This project is eligible for the 20 percent bonding option under the
> following conditions:
> * The permit application must include a general description of
> the proposed slurry wall.
> * The permit application must include a commitment stating
> that the slurry wall design, specifications, and quality assurance plan
> will be approved through the technical revision process prior to
> exposure of ground water in the pit (ground water may be exposed as
> necessary for the construction of the slurry wall in accordance with an
> approved TSSP).
> * A construction report will be provided to DMG following
> installation of the slurry wall. DMG must be satisfied that the
> construction of the slurry wall was completed such that there is a high
> degree of assurance that the wall will meet performance standards
> established by the State Engineer. If the construction report is found
> to be deficient, DMG may increase the bond to between 20 percent on up
> to and including 100 percent of the estimated cost to replace the slurry
> wall.
> If you have any further questions, call me at 303-866-4063.
> -Allen