HYDRO26755

• Permit No: M1982090
• IBM Index Class Name: Hydrology
• Doc Date: 8/25/1994
• Doc Name: AMENDMENT 1 RATINALE CAMP BIRD OF COLO INC CAMP BIRD MINE PN CO-0026981 OURAY CNTY
• Media Type: D
• Archive: No

~ ~'.
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale, Page 2 Permit No. CO-0026981
AMENDMENT N0. 1:
In a letter dated October 3, 1988, William C. Robb, the attorney for Chipeta
Mining Corporation, requested an amendment for this permit which reflects the
recently adopted ambient-based water quality standards, now that the Water
Quality Control Commisssion decision on the temporary modification for Canyon
Creek has been published in the Code of Colorado Regulations. The changes in
the ambient-based water quality standards were amended on August 1, 1988 and
became effective on September 30, 1988. These changes include the following
items:
a) Segment 9 was split into two segments:
Segment 9a - Mainstem of Canyon Creek from its inception at the
confluence of Imogene and Sneffles Creek to the Waterhole Slide.
Mainstem of Imogene Creek from its source to its confluence with
Canyon Creek, Mainstem and all tributaries of Sneffles Greek from a
point 1.5 miles above its confluence with Canyon Creek.
Segment 9b - Mainstem of Canyon Creek from Waterhole Slide to the
confluence with the Uncompahgre River.
Both Segments 9a and 9b are in Region 10, Uncompahgre River Sub-basin,
Uncompahgre River Basin, on page 10 of 17 of the Classifications and
Numeric Standards for the Gunniso^ and Lower Dolores River Basins.
e Gamp Bird Mine discharge points go into
9a.
The new segments are shown in figure 4 of the permit.
b) The changes in the ambient-based water quality standards for Segments
9a and 9b from the original standard for Segment 9 are as follows:
Table 1: Changes in Water Quality Standards
Parameter,mgil
Cadmium, Total Recov.
Copper, Total Recov.
Lead, Total Recoverable
Mercury, Total
Silver, Total Recov.
Zinc, Total Recoverable
Newly Adopted Segments:
Segment 9a Segment 9b
0.0018 0.0011
0.023 0.017
0.120* 0.058
0.037**
0.0001 0.0001*
0,00005**
0.00014 0.0002
0.44 0.31
Previous Segment:
Segment 9
0.0012
0.012
0.008
0.00005
0.0001
0.3
* Temporary modifications: lead (segment 9a) -effective from 9/30/88
to 12/31/90
mercury (seg. 9b) - effective from 9/30/88
to 12131189
** Final numeric standards: lead (segment 9a) - effective beginning 1/O1/91
mercury (seg. 9b) - effective beginning 1/01/90
The numeric water quality standards for the other parameters in segments 9a
and 9b remain unchanged from what was originally in segment 9, including: