INSPEC33704

• Permit No: C1981019
• IBM Index Class Name: Inspection
• Doc Name: Inspection Report
• Inspection Date: 8/22/2007
• Media Type: D
• Archive: No

Colowyo C-1981-019
22 August 2007 ~~
Pg 4/7
Hydrologic Balance (cont.): -Sump 1 was dry at the time of the inspection; the
bottom of the sump was only muddy. The sump was stable at the time of the
inspection.
-Sump 2 contained water approximately three feet below the top of the sump at the
time of the inspection but was not discharging. The sump was stable at the time of
the inspection.
-Sump 3 was dry at the time of the inspection. The sump was stable at the time of
the inspection.
-Sump 4 was dry and was not discharging at the time of the inspection. The sump
was stable at the time of the inspection.
-Sump 5 was dry and was not discharging at the time of the inspection. The sump
appeared to be stable at the time of the inspection.
-The operator had a contractor (Anson) on site construction the West Taylor Pond.
Anson is construction the embankment. The West Taylor Pond has been completed
with the exception of the trash rack on the discharge pipe, the flume to measure
discharge and two short sections of railing on the walkway out to the discharge pipe.
The operator used material from a borrow area approximately 200 feet above the
inlet to the pond. The emergency spillway is an open channel trapezoidal design
that has been riprapped from the top of the embankment down to the receiving
stream/drainage. Tom Peterson (a Colowyo consultant and PE) stated that all of the
proctor tests have shown compaction of well over 90%. Although the material
compacted well, laboratory tests indicated that it was just below the acceptable
level of plasticity for the embankment. Since no other material of higher plasticity
was readily available, Colowyo modified the design slightly to add afabric-wrapped
gravel drain at the toe of the pond embankment. The drain extends approximately
1 /3 of the way under the embankment to decrease the possibility of water piping in
the embankment and causing instability and possibly failure. The primary discharge
pipe is in place in the embankment and has been cut to the proper elevation and
the weep-holes have been drilled at the permanent pool elevation. The discharge
point for the pipe has been riprapped to protect it from erosion and, as stated
above, a flume will be installed to measure the flow of the discharge. The topsoil
from the pond's footprint has been stockpiled on the slope above and west of the
pond. Colowyo will submit a construction report and an as-built upon completion.
Based on the inspection, it appears as though the pond was constructed in
accordance with the designs and good construction practices. **See pictures at
the end of this report.
- Colowyo has stripped the topsoil for the Section 28 Pond. The area a bit past the
outer toe of the pond has been stripped to allow for a buffer during construction.
The topsoil has been stockpiled just below where the pond embankment will be
located. The Division believes that an alternate topsoil stockpile location would be
better because of the current stockpile's proximity to the pond embankment.
Colowyo has an approximately 10,000 yard deficiency in material needed to
construct the embankment and is looking at possible borrow areas for the material.
The pond is planned for construction in the next few weeks.