HYDRO24194

• Permit No: M1980244
• IBM Index Class Name: Hydrology
• Doc Name: AMENDMENT 1 RATIONALE CRIPPLE CREEK & VICTOR GOLD MINING CO A JOINT VENTURE BETWEEN PIKES PEAK MININ
• Media Type: D
• Archive: No

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COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 19. Permit No. CO-0024562.
(b) Monitoring Frequency: The permittee requested that the
monitoring frequency be decreased from weekly to twice monthly. This
change was requested for the following reasons: the effluent quality
has been consistant over the life of the permit and weekly monitoring
would be expensive both for the analysis itself and for the personnel
costs to travel to the discharge point. The Division will allow
decreased monitoring as long as there is no active mining or
exploration based on the consistant quality of the discharge. Once
any active mining or exploration occurs in the Carlton Tunnel,
monitoring frequency will increase to weekly. The permit and
rationale Have been changed to reflect these monitoring requirements.
The Division does recognize that the discharge point is not
conveniently accestable. A provision has been included in the permit
to exempt the permittee from collecting samples when weather
conditions make travel on the Gold Belt Scenic Byway impossible or
unsafe.
(c) Whole Effluent Toxicity Testing: The permittee has requested
that acute and chronic whole effluent toxicity testing be performed
with the Daphnia magna instead of the Ceriodaphnia sp. The Division
is only able to approve the use of other species if their sensitivity
to potential pollutants is equivalent to or more than that of
Ceriodaphnia sp. and if there are acceptable methods and procedures
for testing alternate species. This demonstration has not been made.
If the permittee would like to supply the necessary information to
make this demonstration, the Division will consider the approval. No
changes have been made to the permit at this time.
(d) Footnote 1/: The permittee requested that the parameter names in
the footnote be changed from total recoverable to potentially
dissolved to be consistant with the requirements of the permit. This
change has been made in the permit.
(e) Facility Contact: The facility contact has been changed to read
E.T. Hunter, Manager, Permits and Cultural Resources.
2. Comments made by EPA:
(1) WET Limits: EPA objected to the lack of enforceable WET limits.
WET limits have been added to the permit.
(2) Cadmium and Mercury Monitoring: EPA felt that cadmium and
mercury should be at least monitored when no mining activity is
occurring in the Carlton Tunnel. EPA noted that background cadmium
levels are above the chronic stream standard as shown in Table VI-2.
Upon review, it was discovered that Table VI-2 is incorrect. The
chronic stream standard for cadmium is 0.0021 mg/1 not 0.0002 mg/1 and
is greater than the ambient concentration of 0.00055 mg/1. The table
has been corrected. Past cadmium and mercury concentrations in the
discharge have been consistant and less than the stream standards.
Monitoring for both parameters will be included if any mining activity
occurrs in the Carlton Tunnel. Monitoring for these parameters will
not be added to the permit for discharges preceeding any mining
activity.