1989-10-10_REVISION - M1988112 ‎(12)‎

• Permit No: M1988112
• IBM Index Class Name: Revision
• Doc Date: 10/10/1989
• Doc Name: GENERAL OPERATION INFORMATION
• Type & Sequence: AM1
• Media Type: D
• Archive: No

Some aeolian (wind-blown) deposits were identified
• locally during the exploration program. Nuclear density testing
indicated low density and, therefore, a high void ratio (up
to 1.0) for some of these deposits. Nuclear density test
results are included in Appendix D of the approved permit. Due
to the relatively shallow depth and infrequency of occurrence,
these aeolian deposits will be excavated during :site grading.
Data on the extent of the alluvial/colluvi~al soils and
the nature of the underlying Santa Fe Conglomerate in the area
of the tailings disposal facility is presented inn Appendices
C and D of the approved permit. The borehole and test pit logs
indicate that the alluvial/colluvial soils range in thickness
from 0 to 60 ft. The soils range from sandy clays to clean sand
and gravels. The same range of material types was noted in the
Santa Fe formation except that the formation is generally
lightly cemented and denser.
• Data on the permeability of the alluvial soils and
underlying Santa Fe Conglomerate is presented in Appendix E 1
of the approved permit. The permeability values range from 1 ~1 ~
x 10-s cm/sec to 5 x 10-a cm/sec for the Santa Fe formation and ~
are typically 1 x 10-' cm/sec for the alluvial/colVuvial soils.
Additional information on the permeability of both the
soils and Santa Fe was obtained during a supplemental borehole
program in September 1989. The supplemental program was used
to gain additional information on the permeabilities of
subsurface materials in the vicinity of the tailings disposal
area and on groundwater in the area. The groundwater
information will be further discussed in Exhibit G of this
report. Four borings were drilled immediately downgradient of
the collection pond. The borings were drilled in a staggered
line at a spacing of approximately 10 feet between each boring.
The subsurface material in each boring was similar and logs
for the two deepest boreholes, BH-12 and BH-13 are included
•
D-25