Module 13: Impoundments
Provide the following information for each impoundment that will be used in operations under this permit. Organize
the information by site and facility.
Identify the impoundment so that it can be keyed to Exhibit
Describe the function of the impoundment.
specific cross sections of the impoundment showing: the principal spillway, dewatering pipe,
depth of water, crest of emergency spillway, maximum height of embankment, and existing ground.
section Exhibit 13.1
Describe the potential effect of mine subsidence on the impoundment structure.
Provide plans and describe procedures to compute accurate discharge flow rates from sediment and
treatment pond princi
pal spillways and dewatering pipes. The field system as well as the calculation
method must be usable by monitoring personnel and PADEP mine inspectors.
Detailed Design Plan
Include a design report, capacity calculations, construction plans, construc
tion specifications, and
13.2A. If the embankment is more than 20 feet in height as measured from the upstream toe of the
embankment to the crest of the emergency spillway, or has a storage volume of 20 acre feet or more provide
a stability analysis.
All plans must be certified by a licensed professional engineer. Impoundments must be
certified by a licensed professional engineer and approved by the Department before being put into service.
Compliance with 25 Pa Code Chapter 105
r or not the impoundment meets the criteria for coverage under Chapter
drainage area exceeding 100 acres, water depth exceeding 15 feet (measured by the upstream toe of the
dam at maximum storage elevation), or impounding capacity exceed
feet at maximum storage
elevation. Applications for Chapter 105 dams are subject to additional application fees (see Module 1:
Section E, Application Fee).
Describe the quality of water that will be contained in the
Where impounded water has the potential to cause groundwater contamination or to aggravate an
existing groundwater problem:
Show the liner on the cross section drawings in Module 13.1; and
Complete Module 14.
Operation and Maintenance
Describe the operation and maintenance requirements for the structure, including:
Scope and frequency of inspections;
Dewatering of runoff collection ponds following storm events;
Sludge removal operations;
Maintenance of embankments and liner
IMPOUNDMENT DESIGN AND CERTIFICATION
Commonwealth of Pennsylvania
Department of Environmental Protection
Bureau of Mining and Reclamation
Complete first page and submit with permit
application. Use both pages to certify completed impoundment.
Sedimentation ponds and other impoundments must be constructed in accordance with the approved permit before any disturbance
of the area to be
drained into the pond. Impoundment must be inspect
ed during construction under the supervision of, and certified to the Department upon completion of
construction by a licensed professional engineer or licensed professional land surveyor.
Any enlargement, reduction in size, reconstruction, or other modifi
cation, that may affect the stability or operation must be approved by the Department.
Pond must be certified and approved prior to the start of any other mining activities (see reference sheet
4 of this module).
Unless otherwise specified in
your permit, use this form for the sedimentation pond and other impoundment certification. Submit 1 original and 2 copies to
the appropriate District Mining Office. All information must be provided, otherwise it will be returned for completion.
Location (point of discharge):
corner of U.S.G.S.
HYDROLOGY: Drainage Area
Average Watershed Slope
Top Width (Minimum)
Outside Slope (Maximum) (_H: _ V)
Inside Slope (Maximum)
Upstream Toe Elevation
Downstream Toe Elevation
Amount Allowed for Settlement
Type of Cover
Incised Slope (if any)
Inside Slope (Maximum) (_H: _V)
Discharge Regulation (i.e., self draining or valve)
Discharge Capacity (cubic feet/second)
Time to Dewater Full Pond
Conduit Diameter (if barrel/riser give both)
Depth (with 2 feet of freeboard)
Type of Lining/Protection
Spillway Capacity (provide design calculations)
Length @ Bottom
Width @ Bottom
Length @ Dewatering Device
Width @ Dewatering Device
Volume @ Dewatering Device
Length @ Crest of Principal Spillway
Width @ Crest of Principal Spillway
Volume @ Crest of Principal Spil
Length @ Crest of Emergency Spillway
Width @ Crest of Emergency
Volume @ Crest of Emergency Spillway
TO BE COMPLETED AFTER CONSTRUCTION
Has the facility been constructed at the location shown in the approved permit?
Is emergency spillway constructed in original ground?
And is the type of construction adequate for the required duration and
discharge of the design storm? If “no”
Are the collection channels inlets constructed at the proper
and located to prevent short
Has the pond liner been
constructed as outlined in Module 14? (Provide liner
If not constructed as approved, answer the following questions:
Is the “as constructed” design capable of meeting the performance standards?
If “no” checked, explain.
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Date of Inspection
Stage of Construction
Supervising Professional Engineer
I certify that the above
is complete and has been constructed as indicated.
Signature of Professional Engineer/Surveyor
Registration Number and Expiration
Signature of Permittee or Responsible Official
Principal Spillway Principal Spillway
(Barrel/Riser) (Barrel Only)
(To be Constructed in Original Ground)
Top Elev. &
Downstream Toe Elev.
Depth + 2’
Depth + 2’ of
Reference Sheet for Form 13.2A