PROJ00455

• Contract/PO #: C153583
• Contractor Name: Ute Water Conservancy District
• Water District: 0
• Bill Number: XB 99-999
• Loan Projects - Doc Type: Feasibility Study

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Section VI (Crom Station 764+05 to Station 767+25)
The subsurface conditions along this section can be characterized as river bed
deposits, consisting of cobbles, gravel, and sand. The thickness of this material is
estimated to be between 30 to 40 feet. Based on CDOH bore-hole information and
interviews with local contractors with previous construction experience near the
Colorado River, the subsurface material at this location consists of a layer of gravel
with occasional boulders 4 to 5 feet in thickness. This layer overlays a series of
sandy silt and gravelly sand layers with occasional boulders to depths of up to 40 feet
below the stream bed.

Section VII (from Station 767+25 to Station 810+25)
The subsurface condition along this section consists of flood plain alluvial deposits
consisting of fines and silt overlaying sandstone bedrock. The depth to bedrock is
estimated to be more than 30 feet below the existing ground surface. Due to the
close proximity of the Colorado River the subsurface materials are expected to be
saturated. The area along the Colorado River contains dense to very dense riparian
vegetation.

Section VIII (from Station 810+25 to Station 814+75)
The subsurface condition along this section can be characterized as river-bed
deposits, consisting of cobbles, gravel, and sand. The thickness of this river deposited
material is estimated to be between 40 to 50 feet.

Section IX (from Station 814+75 to Station 816+25)
The subsurface condition along this section consists partly of natural soils and partly
embankment material used in construction of 1-70. The natural soils and
embankment materials are anticipated to be similar to natural soils encountered
along section I and II. There is the possibility for large boulders in the embankment
material. Groundwater along this section at the proposed excavation depths is
estimated to be 10 to 15 feet below the existing 1-70 surface.

Section X (from Station 816+25 to Station 822+21)
The subsurface conditions along this section can be characterized by relatively thin
layers of alluvial and colluvial deposits mainly consisting of sand, gravel and boulders
overlaying the sandstone bedrock. The depth to bedrock is estimated to be from 5
to 10 feet below the existing ground surface. Groundwater along this section to the
proposed pipeline installation depth is anticipated to be non-existent.

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