GENERAL43181

• Permit No: C1981037
• IBM Index Class Name: General Documents
• Doc Date: 7/15/1994
• Doc Name: FIELD DIRECTIVE GEC ORPHAN PIT BOND REVOCATION PROJECT
• Permit Index Doc Type: RECLAMATION PROJECTS
• Media Type: D
• Archive: No

iii iiiiiiiiiiiii iii
• y 999
FIELD DIRECTIVE
G.E.C.- Orphan Pit- Bond Revocation Project
July 15, 1994
Work Changes at the Harrison Western Area (Tasks 2A, 3A and 3C)
2A. West Pit Pond Cleanout
The West Pit pond cleanout described in task 2A of the GEC-Orphan Pit
Bond Revocation project is hereby deleted from the scope of work.
3A. Magpie Creek Diversion
With the deletion of task 2A, task 3A is hereby modified to the
following specifications. Both the primary and emergency spillway
culverts from the West Pit pond will be removed. The culverts in the
undisturbed drainage area will also be removed. The culverts will not
be used for any other scope of work in the bid document. The Magpie
Creek embanl~ent by the West Pit pond will be repaired, and will be
addressed in task 3C as the ditch outflow point. The Magpie Creek
embankment eroded by the undisturbed drainage area will be backfilled
with fill material from the adjacent area, compacted and revegetated.
The outslopes of Magpie Creek embankment will be 3:1 or blend with the
existing slopes. Work in Magpie Creek shall be limited to repair of
the embaril®ent as specified in this directive.
3C. West Pit Diversion
The West Pft Diversion task has been deleted and replaced with the
following design and specifications. The current West Pit design will
join the native channel with the West Pit Diversion ditch above the
current existing West pit Pond and outfall into Magpie Creek below the
pond. This area will be marked by the PROJECT MANAGER. There are two
transition areas that require rip-rap located above the pond in the
native channel and the Hagpie Creek Diversion. Rip-rap lengths at the
top transition are 100 feet and 175 feet at the Magpie Creek
transition area. The transition areas should be no steeper than 8$ in
grade with a minimum 15 foot bottom width and 2H:1V sideslopes. The
total channel depth should be 2 feet at the top of the rock and the
rip-rap thickness should be 1.5 feet. Rip-rap should be as follows:
D~ = 0.9 feet
D50 = 0.75 feet
D10 = 0.25 feet
Riprap must be well graded, angular in shape, and of excellent
durability. The installation must be keyed in at the top and the
bottom of the channel. It will also be necessary to install a filter
layer of approximately 1/2" to 2" gravel, approximately 10 to 12
inches deep beneath the rip-rap.