REV96528

• Permit No: C1981023
• IBM Index Class Name: Revision
• Doc Name: REQUEST FOR PHASE II BOND RELEASE AT KAISER VENTURES INC CHIMNEY ROCK MINE
• Type & Sequence: SL3
• Media Type: D
• Archive: No

4.8 Control Practice Factor (CP}

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4.8.1 Pre-mining State
A CP value of 0.031 is developed in Paragraph 2.8 for the Rangeland Reference Area (1996
Vegetation Sttrvey).
A CP value of 0.182 is developed in Paragraph 2.8 for the Exhibit 5 reference.
A CP of 1.2 is used for the compacted dirt road.
4.8.2 Reclaimed State
A CP of 0.08 is used for the graveled road and the facilities bench area (Meyer, et. al., for
60% rock cover).
Based on information from Transects 4 and 10, South Slope, 1996 Vegetation Survey, a CP
factor of 0.028 is developed in the following table for the uppermost watershed.
Table 4.8.2-1 Uppermost Watershed, Facilities Area (Reclaimed) CP Value
% Ground Cover In Contact With Ground Surface
No appreciable 60 71 ~ 80
canopy
~
I CP Factors
100% grass' 0.042 ~ 0.013
96% grass= 0.044 ~ 0.028 ~ 0.014
100% weeds 0.090 0.043
(forbs)'
' Table S.Sc SEDCAD+ documentation.
- Includes grasses, litter and rocks, 1996 Vegetation Survey.
A CP factor of 0.42 for the steep cut and fill slopes above and below the facilities area is
taken from Table S.Sc of the SEDCAD+ documentation for 60% cover in contact with the
ground surface, no appreciable canopy, 99% grass.
' 4.9 Grass Filter
The entire width of the AVF area would act as a grass filter for runoff of the Facilities Area
' prior to such runoff reaching the natural stream in the area (Stollsteimer Creek). In this
analysis, the first 100 feet of AVF is considered as a grass filter. The grasses are equated
to a fescue in the SEDCAD+ selection tables, with a stem to stem spacing of 2 inches. The
Page l5 of 3d, 7 Oct 96