PERMFILE54992

• Permit No: C1982056
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: OLD
• Section_Exhibit Name: EXHIBIT 25p Pavement Evaluation & Recommendation, Fish Creek Borehole Access Road
• Media Type: D
• Archive: No

• The subgrade soils generally consisted of either natural sandy clays, sandy silts or sandy clay fill
materials, which typically classified as CL to ML soils in accordance with the Unified Soil Classification
System. The clays and silts will generally provide poor to fair subgrade suppon for the pavement
sections. The clay fill materials, natural clays and silts encountered beneath the Haul Road B Extension
and Fish Creek Borehole Access Road were typically sandy, dry to moist, stiff and low to moderately
plastic. The clay fill materials encountered beneath the West Refuse Pile Haul Road were contaminated
with coal, loose to soft, moist to very moist and low to moderately plastic. The natural clays
encountered beneath this roadway were generally sandy, moist to very moist and soh to medium stiff.
Free groundwater was not encountered in any of the test holes at the time of this investigation; however,
the test holes were backfilled immediately upon completion of the drilling or excavation.
The road base gravel and subbase gravel thicknesses aze shown in the following table, along with the
type of subgrade soil encountered and the location of the test holes.
Test Location Road Base Subbase subgrade
Hole Depth Depth Soil Tvoe

West Refuse Pile Haul Road
1 West End 0" 0" FILL: Sandy Clay (CL)
2 West I /2 -Bottom of Hill 0" 5" FILL: Clay (CL)
• 3
4 East 1/2 -Top of Hill
E
E
d 0"
0" 24"
12" CLAY (CL)
CLAY
CL
ast
n (
)
Haul Road B Extension
5 East End 9" 12" FILL: Sandy Clay (CL)
6 Wes[ End 6" 12" FILL: Sandy Clay (CL)
Fish Creek Borehole Access Road
l3 0.2 miles southeast of Borehole 9" 0" CLAY (CL)
14 0.6 miles southeast of Borehole 6" 0' CLAY (CL)
IS 1.0 miles southeast of Borehole 5" 0" CLAY (CL)
16 1.4 miles southeast of Borehole 8" 0" SILT (ML)
Pavement Section Recommendations: Based on our observations of the current traffic use patterns and
condition of the roads, the data obtained from the field and laboratory investigations and our experience
with similar projects we believe that the majority of the problems associated with the subject roadways
are attributed to inadequate drainage conditions, poor subgrade soils and an inadequate gravel section.
For the adequate performance of any roadway, positive drainage must be provided and maintained. This
includes periodic cleaning and regrading of the drainage ditches along the edges of the roadways. In
addition, the roadway surface should also be graded on a periodic basis to ensure that sufficient crown or
• super elevation is maintained so that the gravel surface adequately drains to the ditches. Ponding along
the roadway surface must be avoided.
lob No. 99-1(xu Northwest Colorado Consulunts, Inc. Page 7