_REPORT - M1977448

• Permit No: M1977448
• IBM Index Class Name: Report
• Doc Name: BLACK HOLDINGS & PA
• From: BLM
• To: PETE KILBOURNE
• Media Type: D
• Archive: No

I
mines in La Sal Greek Canyon when considering downstream effects coward Paradox ,
► v Colorado, approximately 15 miles downstream.
South and North Cottonwood Creeks - Laura, King Edward, Yellow Circle, and
Horseshoeimines
The Laura and King Edward Mines, along with 10 other mines and prospects , are
contributing mine waste to South Cottonwood Creek. The cumulative impacts
probably fall into the intermeWate scenario described above. Evaluation of
1 the cumulative effect would require stream sampling above and below these
mines. However, at least thirtyfive other mines and prospects are located on
BLM land further downstream. It is unknown if the relatively high levels of
radiation measured in the spring emerging from a closed portal at the King
1 Edward are entering the stream environment of South Cottonwood Creek,
The Horseshoe Mine lies along an intermittent drainage tributary to North
1 Cottonwood Creek. The Yellow Circle lies directly within the ephemeral wash
bottomm of Kane Springs Gulch, a drainage which probably could be classified as
intermittent further down. These areas contains only a few mines and would
1 fall into the intermediate impact scenario or less.
Brushy Basin #31 and Rex Group
The isolated location and lack of close proximity to perennial or major
intermittent streams indicate that the impacts of these mines are localized and
therefore and follow the least impacting scenario,
?taste Rock Volume Discrepancies
a The Bio Hest estimates of waste rock on-site were consistently lower than DOES
estimates of waste generated. The estimates were consistent in that a list
showing waste estimates for each mine from hi3hest to lowest would match for
relative position. The differences in estimates can be explained by the
following: (1) The material was hauled off-site by the miner. Mixing of high
and low grade ores was a common practice and it probably accounts for the
majority of the differences; (2) The material was eroded and carried downstream;
or (3) Differences in methods of measure between Bio West and DOE. In the case
of the Rex Group, an analysis of recent 1:4800 air photos indicates that the
volume of waste is close to the DOE figure for waste generated. On the other
hand, for many of the other mines the Bio West estimates appear to more closely
approximate the volumes of waste rock onsite.