2002-05-01_REVISION - M1983067

• Permit No: M1983067
• IBM Index Class Name: Revision
• Doc Date: 5/1/2002
• Doc Name: Responses to 2nd adequacy review
• From: Lafarge
• To: DMG
• Type & Sequence: AM1
• Media Type: D
• Archive: No

LAFARGE RECEIVED
NORTH AMERICA MAY 0 1 2002
Construction Materials
Division of Minerals and Geology
April 3Q 2002
Mr. Thomas A. Schreiner Permit #: ~ ~?-O ~ Confidental?:
Environmental Protection Specialist Class: Type-Seq.: ~"^• v
Division of Minerals and Geology From: To:
1313 Sherman Street, Room 215 Doc. Nam .
Doc. Date (if no to stamp):
Denver, Colorado 80203
RE: Responses to 2"d Adequacy Review Questions -Amendment No. 1 Application
Permit No. M-1983--67
Dear Mr. Schreiner:
In response to your letter dated April 17, 2002, Lafarge West, Inc. (Lafarge) and our consultants
Banks and Gesso, LLC (B&G) have prepared the following responses to your questions. Our
responses are presented in the same order as your questions. In some cases, the answers and/or
responses to your questions can be found on the accompanying attachments and or exhibits.
6.4.1 Exhibit A -Legal description and Location Map
1) The legal description of the 2.5 acres to be removed has been added to Exhibit A.
Exhibit B has also been updated to reflect the removal of the 2.5 acres. Exhibits A and B
can be found as attachments.
2) Attached is a revised page 1 to our 112 Amendment Application that indicates a total
acreage of 52 acres within the permitted mining area.
6.4.7 Exhibit G -Water Information
It is not our intention to install the french-drain system at the same time as the slurry wall. Our
rationale for waiting on the installation of the french-drain system involves the direction of the
groundwater flow in the area of the property. The current information on the direction of the
groundwater flow indicates that it is not flowing perpendicular to the slurry wall, but at an
approximate 30- to 45-degree angle. That is, it is generally flowing in a northwesterly direction
rather than a westerly direction. The potential exists that the natural flow of the groundwater
may "slide" by the slurry wall rather than mound up, thereby negating the need for the french-
drain system. It is our intention to study the groundwater flow based on our monitoring wells
and then determine if the french-drain system is needed.
LAFARGE WEST, INC.
1590 W. 12th Ave., Denver, Colorado 80204-3410
Office: [phone] Fax: [phone]
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