(a) Dams,
ponds, embankments and impoundments that meet the following criteria shall be
designed, constructed and maintained under Chapter 105 (relating to dam safety
and waterway management):
(1) Dams located on
a natural or artificial water course where one of the following applies:
(i) The contributory drainage area exceeds
100 acres.
(ii) The greatest depth
of water at maximum storage elevation exceeds 15 feet.
(iii) The impounding capacity at maximum
storage elevation exceeds 50 acre-feet.
(2) Structures used for the storage of water
not located on a watercourse and which have no contributory drainage where the
greatest depth of water, at maximum storage elevation, exceeds 15 feet and the
impounding capacity, at maximum storage elevation, exceeds 50 acre-feet.
(b) The design,
construction and maintenance of dams, ponds, embankments and impoundments shall
achieve the minimum design criteria contained in the United States Natural
Resources Conservation Service's
Pennsylvania Field Office Technical
Guide, Section IV, Standards 350 "Sediment Basin" and 378, "Pond," or
United States Natural Resources Conservation Service's Technical Release No.
60, Earth Dams and Reservoirs, whichever is applicable. The standards are
incorporated by reference. In addition to the requirements in "Sediment Basin,"
a minimum static safety factor of 1.3 is required. These structures shall meet
the following requirements:
(1) The detailed
design plan for a structure shall be prepared by and certified by a qualified
registered professional engineer. Each impoundment shall be certified that the
impoundment has been constructed and is being maintained as designed in
accordance with the applicable performance standards.
(2) Each pond shall be inspected once every 3
months for structural weakness, erosion and other hazardous conditions. The
person who conducts the coal refuse disposal activities shall make and retain
records of the inspection, including records of actions taken to correct
deficiencies found in the inspection. Copies of the records shall be provided
to the Department on request.
(3)
The entire embankment, including the surrounding areas disturbed by
construction, shall be stabilized with respect to erosion by a vegetative cover
or other means immediately after the embankment is completed. The active
upstream face of the embankment where water will be impounded shall be
riprapped or otherwise stabilized. Areas in which the vegetation is not
successful or where rills and gullies develop shall be repaired and
revegetated.
(4) Plans for
enlargement, reduction in size, reconstruction or other modification of dams or
impoundments shall be submitted to the Department and shall comply with this
section. Except when a modification is required to eliminate an emergency
condition, constituting a hazard to public health, safety or the environment,
the plans shall be approved by the Department before modification
begins.
(c) If the
embankment is more than 20 feet in height as measured from the upstream toe of
embankment to the crest of the emergency spillway, or has a storage volume of
20 acre feet or more, is located where failure could cause loss of life or
serious property damage or otherwise poses a hazard to miners or the public, it
must:
(1) Be stable under probable conditions
of operation and be designed and constructed to achieve a static safety factor
of 1.5 or a higher static safety factor required by the Department.
(2) Have an appropriate combination of
principal and emergency spillways to safely pass, adequate storage capacity to
safely contain, or a combination of storage capacity and spillway capacity to
safely control, the probable maximum runoff from precipitation of a 6-hour
precipitation event.
(3) Have a
foundation investigation, as well as necessary laboratory testing of foundation
material to determine the design requirements for foundation
stability.
(d) An
impoundment shall be inspected during construction and certified after
construction, and annually thereafter, by a qualified registered professional
engineer until removal of the structure. Certification reports shall include
monitoring and instrumentation results and a statement regarding the condition
of impoundment.
(e) An impoundment
shall be examined by a qualified person designated by the operator at intervals
not exceeding 7 days for structural weakness, erosion and other hazardous
conditions. Impoundments with an embankment less than 20 feet in height as
measured from the upstream toe of the embankment to the crest of the emergency
spillway or which have a storage volume of less than 20 acre-feet shall be
inspected once every 3 months unless otherwise required by the Department. If
an examination or inspection discloses that a potential hazard exists, the
person who examined the impoundment shall promptly inform the Department of the
finding and provide a remedial action plan to protect the public. If adequate
procedures cannot be formulated or implemented, the Department shall be
notified immediately. The Department will then notify the appropriate agencies
that other emergency procedures are required to protect the public. The
permittee shall make and retain records of the inspection, including records of
actions taken to correct deficiencies found in the inspection. Copies of the
records shall be provided to the Department on request.
(f) Impoundments subject to
30 CFR
77.216-
1 and
77.216-
2 (relating to water,
sediment or slurry impoundments and impounding structures; identification; and
water, sediment or slurry impoundments and impounding structures; minimum plan
requirements; changes or modifications; certification) shall have duplicate
plans submitted to the District Manager of MSHA and to the Department. The
Department may consider MSHA's review for impoundments. However, the Department
will review impoundments under the requirements of subsection (a).