2016-11-02_PERMIT FILE - C1982057A

• Permit No: C1982057A
• IBM Index Class Name: Permit File
• Doc Date: 11/2/2016
• Section_Exhibit Name: Tab 13 Facilities
• Media Type: D
• Archive: Yes

effluent limitations before discharge from the permit area. The characteristics of the mine site,
reclamation procedures, and onsite sediment control practices are also considered in the design.
b) All sedimentation ponds are designed to provide adequate sediment storage volume in
compliance with the DMG regulations.
c) An appropriate non -clogging dewatering device will be installed to dewater a 10 -year, 24-hour storage
volume.
d) Appropriate combinations of principal and emergency spillways to safely discharge the runoff from a
25 -year, 24-hour precipitation or larger event, as required by the DMG's regulations, will be installed in
all ponds.
The sediment storage capacity of each sedimentation pond or impoundment will be monitored by visual
inspection on an annual basis to ensure that at least one year of sediment storage is available beneath the
principal spillway inlet (based on the R.U,S.L.E. or the equivalent sediment storage of one 10 -year, 24-hour
stone event based on the M.U.S.L.E.). When adequate capacity is no longer available, sediment removal or
other corrective actions will be taken to restore adequate sediment storage capacity to the pond.
During normal water years, sediment ponds 005 and 009 generally have stop flowing mid -summer. Seneca
Property, LLC (SPL) request a variance from the requirement to conduct annual surveys of these sediment
ponds, as required by Rule 4.05.905)(C). In return, SPL will conduct visual inspections of the sediment ponds
once the water levels have dropped and the inlets are visible. If SPL notes sufficient sediment build-up and
storage capacity is hindered, sediment removal or other corrective actions will be taken to restore adequate
sediment storage capacity to the pond.
On average, sediment ponds 006, 015, 016, and 017 show flow year round. SPL has seen minimal loss of
storage capacity within these sediment ponds from 2008 to 2015. Starting in 2016 SPL requests a variance
from the requirement to conduct annual surveys of these sediment ponds, as required by Rule 4.05.9(15)(C). In
return, SPL will conduct surveys of sediment ponds 006, 015, 016, and 017 every five years along with
annual visual inspections as reflected in the following schedule.
Sediment Pond
Inspection Type & Frequency
005
Visual Inspection
006
5 Year Capacity Survey/ Visual
009
Visual Inspection
015
5 Year Capacity Survey/ Visual
016
5 Year Capacity Survey/ Visual
017
5 Year Capacity Survey/ Visual
Next Scheduled Survey
Annual
2020/ Annual
Annual
2020/ Annual
2020/ Annual
2020/ Annual
MR -83 4 Revised 10/16