PERMFILE137301

• Permit No: C1981019
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: Sections 6 - 9
• Section_Exhibit Name: Exhibit 12 Experimental Part 2
• Media Type: D
• Archive: No

.,
• (November 1975) and "Report on Preliminary Design of Open
Pit Slopes" (April 1975) by W.A. Wahler & Associates of Falo
.Alto, California, and the "Draft Environmental Impact State-
ment, t,line and Reclamation Plan" (Volume III, 1976) prepared
for 1l'.R. Grace and Company. These studies provided general
background information as well as some specific data relating
to hydrology and geology. The majority of the information
in VVahler's waste design report related to the higher areas
of the site underlain by thin residual soils over shallow
bedrock and .vas not directly applicable to tl~e thick colluvium
' deposits in St=•eeter Canyon.
2.0 FIELD EXPLORATIONS AND LABORATORY TESTI
The subsurface conditions within Streeter Canyon were
r explored by drilling eleven test borings and excavating four
test pits. The exploration was limited to an area within
~• about ?,000 feet of the canyon mouth, since this was the area
of primary concern. The test borings were drilled with con-
L tinuous flight 4-inch solid stem augers and ranged in depth
from 35 to 84 feet. Observation wells to monitor the ground
water table level were installed i[i borings BH-10G, BH-109,
and BH-110. The test pits were excavated with a small back-
hoe supplied by Colowyo and were excavated to a maximum depth
of 13 feet. The locations of the explorations are shown on
Figure 1, while the boring and test pit logs are included in
the Appendix. The explorations were located in the field by
us and subsequently surveyed in by Colowyo personnel.
~_
In the borings, soil samples were generally taken at
5-foot intervals using a standard 2-inch split spoon sampler.
The sampler was driven with a standard weight of 140 pounds
1 falling a distance of 30 inches. The number of blows re-
`z. quired to drive the sampler 12 inches into the soil is shown
I •
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