2002-02-18_REVISION - M1977436

• Permit No: M1977436
• IBM Index Class Name: Revision
• Doc Date: 2/18/2002
• Doc Name: Adequacy Questions
• From: DMG
• To: Aggregate Industries - WCR Inc
• Type & Sequence: TR4
• Media Type: D
• Archive: No

STATE OF COLORf~DO
DIVISION OF MINERALS AND GEOLOGY
Department o£ Natural Resources
1313 Sherman SL, Room 215
DIVISION O F
Denver, Colorado 80203
Phone: [phone] !VL I N ~ RA L $
FAX: [phone] &
GEOLOGY
February 18, 2002 RECLAMATION
MINING•SAFETY
Ms. Connie Nickle Davis
A re ate Industries
gg g B01OWeos
Governor
P.O. Box 337231
Greg E Watcher
Greeley, CO 80633 E,e~~ave Do-ecror
Michael B. Long
RE: Aggregate Industries, Brighton Mine, Permit No. M-1977-436 oivl:ion oireaor
Technical Revision 04; Adequacy Questions
Dear Ms. Davis,
The Division has conducted an adequacy review for Technical Revision 04 (TR-4) for the Brighton Mine, Permit No.
M-197736. At [he request of Aggregate Industries, the issue surrounding the filing the revision as a Perntit
Amendment rather than a Technical Revision has been scheduled for the February 20-21 Mined Land Reclamation
Board Hearing as a discussion item. To facilitate this request, Aggregate Industries has requested [ha[ the Division's
decision date be extended to February 22, 2002. The Division has scheduled this issue as a discussion item for the
February 20-21, 2002 Board Hearing. The Board hearing will begin at 10:00 a.m. located at 1313 Sherman Street,
Room #318. The Division still believes [hat this revision to the permit should be handled as an amendment with all of
the notifications involved, and [his adequacy review should not be constmed as agreement that this matter be handled
as a technical revision.
However, in order to address the technical issues surrounding the revision, the Division has identified a number of
items that need to be addressed. These issues are relevant to both filing procedures and must be addressed before a
decision can be rendered.
1. Please describe in further detail the reclamation plan for the North Pond area. Specifically;
a) Please specify if material will be used [o backfill a portion of [he pit [o facilitate [he change from a ground
water lake to a wetland habitat. If off site fill is to be used, please address the roles associated with off site
inert material (Rule 3.1.5(9)).
b) Please specify any new slope configurations proposed for the wetland habitat.
c) Please specify a new seed mixture to achieve the postmining land use of wetland habitat.
d) Aggregate Industries states that 4 feet of the berm will be removed to facilitate floodwaters to enter and
leave [he pit. Please provide a more detailed reclamation plan map that depicts the elevation of the bottom
of the pi[, the elevation of the riverside berm and the elevation of the spillway in relation to the South
Platte River.
2. Aggregate Industries proposes 18" grouted boulders along the pitside of the channel spillways. In accordance with
the Technical Review Guidelines for Gravel Mining- Urban Drainage and Flood Control District ("Guidelines"),
the grout must have a minimum compressive strength of 2,000 psi. As an alternative, a concrete mix having'/r-
inch maximum aggregate, 4-inch slump and 2,000 psi- 28-day compressive strength may be substituted for grout.
In addition, the grout shall be placed in a manner that ensures that all voids within the riprap are filled with grout.
Please commit to such specifications, or provide an alternative method.