2010-10-28_REVISION - M2000082

• Permit No: M2000082
• IBM Index Class Name: REVISION
• Doc Date: 10/28/2010
• Doc Name: Submittal
• From: Aggregate Industries
• To: DRMS
• Type & Sequence: TR1
• Media Type: D
• Archive: No

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4.
October 27, 2010
Mr. Jared Ebert i?
Environmental Protection Specialist
Division of Reclamation, Mining and Safety
1300 Sherman Street, Suite 200 AGGREGATE
Denver, CO 80203
INDUSTRIES
Re: Permit No. M-2000-082 - East 8`l' Street Operation
Technical Revision Request
Dear Mr. Ebert:
In accordance with the corrective action set forth in your March 30, 2010 inspection report for the
above-referenced operation, Aggregate Industries (Al) submits this technical revision request to
modify the current approved groundwater monitoring plan for this site.
Al installed Phase 1 monitoring wells at the East 8"' Street Operation in April, 2003 in accordance
with the current approved groundwater monitoring plan. The approximate locations of the Phase
1 wells (MW-1 and MW-2) appear on the enclosed aerial photo. Four (4) years of monthly
measurements were collected prior to commencement of dewatering at the site in April, 2007, and
monthly measurements continue to be collected at these wells. While Al has not installed Phase
2 monitoring wells north of the operation along Balsam Street as proposed under the current
approved plan, nor did Al. measure Phase 1. and Phase 2 wells weekly during the first two months
of dewatering, local groundwater data is available from another mine in the vicinity operated
under Permit No. M-2008-017 (Derr Pit), located north of AI's East 8 b Street Operation and
adjacent to Balsam Street. Monitoring wells identified as Derr MW-l, Derr MW-2 and
Derr MW-3 on the enclosed aerial provide data similar to that which would have been obtained
from AI's Phase 2 wells.
The Derr Pit wells were installed approximately six (6) months prior to AI's initial dewatering of
the East 8`h Street Operation and measurements were taken by the Derr Pit operator on a monthly
basis. The Derr Pit monthly data from October 2006 through March 2008, together with a map
showing the location of the Derr monitoring wells, was submitted to the Division under the
operator's application for that site's 112 permit. Copies of those documents are enclosed.
The location of the Derr monitoring wells and frequency of monitoring of the Derr wells, in
conjunction with data from AI's Phase l wells, provides a range of relative water levels
associated with pre-mining groundwater conditions and groundwater conditions during the period.
of time that Al initially dewatered the East 8`" Street site. Al therefore proposes that the enclosed
Derr Pit data, together with Al's previously submitted data, be accepted by the Division in lieu of
the originally proposed Phase 2 wells and initial weekly monitoring.
Al proposes to continue collecting monthly data from its Phase 1 wells but would request
elimination of the Phase 2 wells from its groundwater monitoring plan, as those wells would
Aggregate Industries
West Central Region, Inc.
1707 Cole Blvd., Suite 100
Golden, CO 80401
Telephone: [phone]
Connie N. Davis, Land Advisor
P. O. Box 337231, Greeley, CO 80633
Phone: [phone]
An Equal Opportunity Employer