1989-06-28_REVISION - M1988112

• Permit No: M1988112
• IBM Index Class Name: Revision
• Doc Date: 6/28/1989
• From: BATTLE MOUNTAIN GOLD CO
• To: MLRD
• Type & Sequence: TR2
• Media Type: D
• Archive: No

BATTLE MOUNTAIN GOLD COMPANY
SAN LUIS PROJECT
P 0 BOX 310
SAN LUIS, CO 81152-0310
[phone]
III III III III I'11111
999
June 23, 1989
Steve Renner
Mined Land Reclamation
Colorado Department of
1313 Sherman Street
Room 423
Denver, CO 80203
Division
Natural Resources
RECEIVED
JUN a 81989
MINEd LAND
RECLAMATION DIVISION
Mr. Steve Renner:
During recent review of haulage roads and culvert requirements at the San
Luis Project, three areas of interest came to our attention. Since these
areas will require minor modifications or additions to the existing permit,
we would like to bring them to the attention of the MLRD for information
and approval. The three areas of concern are outlined below as follows:
In the permit on Figure D.9-2, "River-Haul Road Crossing,"
Note 2, it states that the CMP is to be galvanized with
2 2/3 x : inch annular corrugations. We intend to install 14
gauge, galvanized CMP with 5 x 1 corrugations at all culvert
crossings. This will improve the structural integrity of the
CMP by increasing the moment of inertia and cross-sectional
area of each culvert (Table 3-2, AISI Handbook, 1983).
Table D.9-2 of the permit specifies two locations where two
culverts are required. We have recently had each of theee
culvert crossings redesigned so that one larger diameter culvert
will accomodate the peak flows at each location. The
locations and CMP diameter changes are summarized below es
follows:
Culvert between the lJest Pit and Waste Disposal
Area C:
Replace 2-42 inch CMP with one 60 inch CMP
(see attached "Culvert Design Summary," Item
2).
South Waste Rock Disposal Facility-Haul Road Culvert:
Replace 2-54 inch CMP with one 72 inch CMP
(see attached "Culvert Design Summary," Item 3).
An additional culvert crossing will be required on the main
haul road at the first drainage south of the Rito Seco. The
catchment area and peak water shed calculations have been
completed for this drainage and this culvert has been sized
for one 48 inch diameter CMP with a HW/D=1.5 minimum. A
summary of the design criteria and results is attached in Item
of the "Culvert Design Summary" and water shed and drainage
criteria are also attached for this area.