The following permit requirements may apply
to certain regulated earth disturbance activities and must be met
prior to commencement of regulated earth disturbance activities, as
applicable:
A. All regulated earth disturbance activities subject
to permit requirements by DEP under regulations at 25 Pennsylvania
Code Chapter 102.
B. Work within natural drainageways subject to permit
by DEP under 25 Pennsylvania Code Chapter 105.
C. Any stormwater management facility that would be located
in or adjacent to surface waters of the commonwealth, including wetlands,
subject to permit by DEP under 25 Pennsylvania Code Chapter 105.
D. Any stormwater management facility that would be located
on a state highway right-of-way or require access from a state highway
shall be subject to approval by PennDOT.
E. Culverts, bridges, storm sewers, or any other facilities
which must pass or convey flows from the tributary area and any facility
which may constitute a dam subject to permit by DEP under 25 Pennsylvania
Code Chapter 105.
The applicant shall comply with the following
water quality requirements of this article.
A. No regulated earth disturbance activities within the
Municipality shall commence until approval by the Municipality of
a plan which demonstrates compliance with postconstruction state water
quality requirements.
B. The BMPs shall be designed, implemented, and maintained
to meet state water quality requirements and any other more stringent
requirements as determined by the Municipality.
C. To control postconstruction stormwater impacts from
regulated earth disturbance activities, state water quality requirements
can be met by BMPs, including site design, which provide for replication
of preconstruction stormwater infiltration and runoff conditions so
that postconstruction stormwater discharges do not degrade the physical,
chemical, or biological characteristics of the receiving waters. As
described in the DEP Comprehensive Stormwater Management Policy (No.
392-0300-002, September 28, 2002), this may be achieved by the following:
(1) Infiltration: replication of preconstruction stormwater
infiltration conditions;
(2) Treatment: use of water quality treatment BMPs to
ensure filtering out of the chemical and physical pollutants from
the stormwater runoff; and
(3) Stream bank and stream bed protection: management
of volume and rate of postconstruction stormwater discharges to prevent
physical degradation of receiving waters (e.g., from scouring).
D. Developed areas shall provide adequate storage and treatment facilities necessary to capture and treat stormwater runoff. The retention volume computed under §
144-20, may be a component of the water quality volume if the applicant chooses to manage both components in a single facility. If the retention volume is less than the water quality volume, the remaining water quality volume may be captured and treated by methods other than infiltration BMPs. The required water quality volume (WQv) is the storage capacity needed to capture and treat a portion of stormwater runoff from the developed areas of the site. To achieve this goal, the following criterion is established:
(1) The following calculation formula is to be used to
determine the water quality storage volume (WQv) in acre-feet of storage required by this chapter:
WQv = [(P)(Rv)(A)] ÷ 12
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Where
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WQv
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=
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Water quality volume (acre-feet).
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P
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=
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1 inch.
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A
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=
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Area of the project contributing to the water
quality BMP (acres).
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Rv
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=
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0.05 + 0.009(I) where I is the percent of the
area that is impervious surface [(impervious area/A)*100].
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(2) This volume requirement can be accomplished by the
permanent volume of a wet basin or the detained volume from other
BMPs. Where appropriate, wet basins shall be utilized for water quality
control and shall follow the guidelines of the BMP manuals referenced
in Appendix G.
(3) Release of water can begin at the start of the storm
(i.e., the invert of the water quality orifice is at the invert of
the facility). The design of the facility shall provide for protection
from clogging and unwanted sedimentation.
E. For areas within defined special protection sub-watersheds
that include EV and HQ waters, the temperature and quality of water
and streams shall be maintained through the use of temperature sensitive
BMPs and stormwater conveyance systems.
F. To accomplish the above, the applicant shall submit
original and innovative designs to the Municipal Engineer for review
and approval. Such designs may achieve the water quality objectives
through a combination of different BMPs.
G. If a perennial or intermittent stream passes through
the site, the applicant shall create a stream buffer extending a minimum
of 10 feet to either side of the top-of-bank of the channel. The buffer
area shall be maintained with and encouraged to use appropriate native
vegetation. (Refer to Appendix H of the Pennsylvania Handbook of Best
Management Practices for Developing Areas for plant lists.) If an
existing buffer is legally prescribed (i.e., deed, covenant, easement,
etc.) and it exceeds the requirements of this chapter, the existing
buffer shall be maintained. [Note: The Municipality may select a smaller
buffer width (above) if desired, but the selected buffer may not be
less than 10 feet]. This does not include lakes or wetlands.
H. Evidence of any necessary permit(s) for regulated earth disturbance activities from the appropriate DEP regional office must be provided to the Municipality. The issuance of an NPDES construction permit [or permit coverage under the statewide general permit (PAG-2)] satisfies the requirements of Subsection
A.