PERMFILE127991

• Permit No: C1980005
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: SMALL AREA EXEMPTIONS
• Section_Exhibit Name: TAB 07 APPENDIX 7-6 ATTACHMENT 7-6-7
• Media Type: D
• Archive: No

~J
HoNF~rARDS AND OFFICE
SMALL ARFA E~PIONS
Introduction
The office and boneyar~i areas at the Seneca
as Small Area Exemptions in Minor Revisions
areas do not drain to a ~l~*~+~ation pond.
total of 5.41 acres of disturbance.
approximately 3,300 acres of drainage area
four sedimentation ponds. The exertion
acres of drainage area or 0.18 percent of
to sediment porrls.
II Mine were approved
3 aryl 11. The three
The areas comprise a
There are currently
that are contained by
areas represent 5.41
the total that drains
A meter model, SEDCAD+, was used for this revision to
demonstrate the viability of alternate sediment control methods.
The shortcmni~xl of the model is that it was designed to estimate
runoff and predict sedimentology for disturbed lands. These
azeas in question aze cot[g>rised of grass lawns, gravel parking
areas, building roofs, and equipment storage areas and are not
really adaptable to SEDCAD input parameters.
Additional Information - December 2, 1993
The areas listed above were sampled for settleable solids during periods
of sncamielt arxi rainfall. That information is summarized on Table
7-6-7-1. The sampling effort was conducted in lieu of silt fence
installation (pending sampling results). Sample results indicate only one
location exceeded 0.5 ml/1; this was sample Site E near the office (see
Figure 7-6-7-1). Runoff from this area contained sediment from the
parking area, which at the time contained mud from the recent rains.
Therefore, this may or may not be indicative of normal operations. The
Seneca Mine proposes the installation of either silt fencing or straw
bales at this location. Information regarding potential silt fence
location and SEDCAD tuns will remain in the application for future use, if
required.
7-6-7-2 Revised 12/02/93