1988-06-21_HYDROLOGY - M1977378

• Permit No: M1977378
• IBM Index Class Name: HYDROLOGY
• Doc Date: 6/21/1988
• Doc Name: Sludge Evaluation
• From: MLRD
• To: File
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

STATE OF COLORADO
N
* * Roy Romer, Governor
*1876
DEPARTMENT OF NATURAL RESOURCES
MINED LAND RECLAMATION DIVISION
FRED R. BANTA, Director
DATE: June 21 , 1988
TO: Ed Bischoff & Camille Farrell
FROM: John T. Doerfer 97�
RE: _,Sludge Evaluation, Sunnyside Gold Corporation, File No. M-77378
As requested, I have evaluated the potential toxicity of sludge from samples
of sediment from the Terry Tunnel at the Sunnyside Gold Mine. My review
indicates this material to be acidic, potentially toxic, unsuitable as a plant
growth media and containing elevated levels of cadmium, copper, lead and
manganese which, from a water-quality perspective, could pose problems in
receiving waters. The sample data have characteristics similar to both the
gray slime from Pond 2 and reddish sludge from the American Tunnel ponds.
The samples were collected from a trench where sediment excavated from the
Terry Tunnel setting ponds was being deposited and allowed to dry. This
location was not an approved disposal area as noted during an inspection by
Camille on October 28, 1987. The issue is whether to proceed with an
enforcement action for failure to comply with the permit or require a revision
to designate this as a disposal area. The concern is whether this material
needs special handling or not. Sunnyside Gold Corporation submitted the
results of chemical analyses and an interpretation that the potential exists
to revegetate these materials, and that the materials could not have been
derived from chemical precipitation of mine drainage waters.
Acid Potential
Analytical tests were performed to determine if the sediment was acid
forming. Total sulfur (%) was determined, and when multiplied by the
stoichiometric ratio of 31 .25, gives acid potential (tons/1000 tons).
Neutralization potential was also determined, and when this value is
subtracted from acid potential the result is the "acid-base potential " or net
neutralization potential (tons/1000 tons ).
The levels measured in the Terry Tunnel sediment were compared to criteria in
the literature (Smith et al . 1974, Sobek et al . 1978). An average value for
the three samples was calculated. A neutralization potential of 15 was less
than the criteria of 20 which indicates the samples are acidic. The average
value for net neutralization potential is -14. If the net neutralization
potential is less than -5, then the material is considered potentially toxic.
215 Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel.[phone]