A.
Written approval of a SWM site plan must be issued by the municipality prior to commencement of regulated activities unless exempt from this requirement under § 203-12.
B.
SWM site plans approved by the municipality shall be on site throughout
the duration of the regulated activity.
C.
The municipality may, after consultation with the PA DEP, approve
measures for meeting the state water quality requirements other than
those in this chapter, provided they meet the minimum requirements
of, and do not conflict with, state law including but not limited
to the Clean Streams Law.[1]
[1]
Editor's Note: See 35 P.S. § 691.1 et seq.
D.
For all regulated activities, implementation of peak rate controls and preparation of a SWM site plan are required, unless exempted by § 203-12 of this chapter.
E.
Impervious areas.
(1)
The measurement of impervious areas shall include all of the impervious
areas in the total proposed development even if development is to
take place in stages.
(2)
For development taking place in stages, the entire development plan
must be used in determining conformance with this chapter.
(3)
For projects that add impervious area to a parcel, the total impervious area on the parcel is subject to the requirements of this chapter, unless the project is otherwise deemed exempt from stormwater management provisions per the criteria set forth in § 203-12 of this plan.
(4)
Existing gravel parking areas, driveways, and roads shall not be
considered impervious. These areas shall be treated as semipervious
and shall be analyzed using the appropriate SCS curve number based
on the appropriate HSG underlying the gravel areas, which is defined
as:
(5)
Proposed gravel parking areas, driveways, and roads shall be considered
impervious.
F.
Stormwater discharges onto adjacent property shall not be created,
increased, decreased, or relocated, or otherwise altered without permission
of adjacent property owner(s). Such discharges shall be subject to
the requirements of this chapter.
G.
All regulated activities shall include such measures as necessary
to:
(1)
Protect health, safety, and property.
(2)
Meet the water quality goals of this chapter by implementing measures
to:
(a)
Minimize disturbance to floodplains, wetlands, natural slopes
over 15%, and existing native vegetation.
(b)
Minimize thermal impacts to waters of the commonwealth.
(c)
Preserve and maintain trees and woodlands. Maintain or extend
riparian buffers and protect existing forested buffer. Provide trees
and woodlands adjacent to impervious areas.
(d)
Establish and maintain nonerosive flow conditions in natural
flow pathways.
(e)
Minimize soil disturbance and soil compaction. Cover disturbed
areas with topsoil having a minimum depth of four inches. Use tracked
equipment for grading.
(f)
Disconnect impervious surfaces by directing runoff to pervious
areas.
H.
The design of all facilities over karst shall include an evaluation
of measures to minimize adverse effects.
I.
Infiltration BMPs shall be spread out, made as shallow as practicable,
and located to maximize use of natural on-site infiltration features
while still meeting the other requirements of this chapter.
J.
Storage facilities shall completely drain both the volume control
and rate control capacities over a period of time not less than 24
and not more than 72 hours from the end of the design storm.
K.
The design storm volumes to be used in the analysis of peak discharge
rates shall be obtained from the Precipitation-Frequency Atlas of
the United States, Atlas 14, Volume 2, US Department of Commerce,
National Oceanic and Atmospheric Administration, National Weather
Service, Hydrometeorological Design Studies Center, Silver Spring,
Maryland 20910. NOAA's Atlas 14 can be accessed at internet address
http://hdsc.nws.noaa.gov/hdsc/pfds/.
L.
The municipality and its engineer may require that regulated activities
maintain a minimum distance between proposed impervious areas/stormwater
management facility outlets and down-slope property line(s).
M.
N.
For all regulated earth disturbance activities, erosion and sediment
control BMPs shall be designed, implemented, operated, and maintained
during the regulated earth disturbance activities (e.g., during construction)
to meet the purposes and requirements of this chapter and to meet
all requirements under Title 25 of the Pennsylvania Code and the Clean
Streams Law.[5] Various BMPs and their design standards are listed in
the Erosion and Sediment Pollution Control Program Manual (E&S
Manual), No. 363-2134-008 (April 15, 2000), as amended and updated.
[5]
Editor's Note: See 35 P.S. § 691.1 et seq.
B.
The applicant must demonstrate that the following BMPs are being
used to the maximum extent practicable to receive consideration for
the exemptions:
(1)
Design around and limit disturbance of floodplains, wetlands, natural
slopes over 15%, existing native vegetation, and other sensitive and
special-value features.
(2)
Maintain riparian and forested buffers.
(3)
Limit grading and maintain nonerosive flow conditions in natural
flow paths.
(4)
Maintain existing tree canopies near impervious areas.
(5)
Minimize soil disturbance and reclaim disturbed areas with topsoil
and vegetation.
(6)
Direct runoff to pervious areas.
C.
The applicant must demonstrate that the proposed development/additional
impervious area will not adversely impact the following:
D.
Proposed regulated activities.
(1)
An applicant proposing regulated activities, after demonstrating compliance with § 203-12 A, B and C, may be exempted from various requirements of this chapter according to the following table:
|
Table 203-12-1
| ||
|---|---|---|
|
0 square feet < new impervious area <1,000 square feet
|
Required: Exempt from additional requirements
| |
|
1,000 square feet < new impervious area <2,500 square feet
|
Required: Small project SWM application (See Appendix F[1]) [NOTE: The municipality can require the applicant to
provide supplemental and additional information beyond the Small Project
SWM Application if there is a threat to property, health or safety.]
| |
|
2,500 square feet < new impervious area <5,000 square feet
|
Required: Volume control (§ 203-14) and small project SWM application (See Appendix F)
| |
|
5,000 square feet < new impervious area
| ||
[1]
Editor's Note: Appendix F is on file in the Borough offices.
(2)
All regulated activities must comply with the state water quality
requirements.
E.
New single-family residential activities on a single lot are exempt from the requirements of §§ 203-14, Volume control, § 203-15, Peak rate control, and from the submission of a Small project SWM application provided the construction:
(2)
Has building setbacks of at least 75 feet from downslope property
lines; and
(3)
Driveways:
(a)
Runoff must discharge onto pervious surface with a gravel strip
or other spreading device.
(b)
No more than 1,000 square feet of paved surface may discharge
to any one point.
(c)
For each discharge point, the flow length on the pervious surface
must exceed the flow length on the paved surface flow.
F.
The municipality may accept alternative stormwater management controls
under this section provided that:
(1)
The alternative controls are documented to be acceptable to PA DEP
(or delegated authority) for NPDES requirements pertaining to postconstruction
stormwater management requirements.
G.
Agricultural activities are exempt from the rate and SWM site plan
preparation requirements of this chapter provided the activities are
performed according to the requirements of 25 Pa. Code Chapter 102.
H.
Forest management and timber operations are exempt from the rate and volume control and SWM site plan preparation requirements of this chapter provided the activities are performed according to the requirements of 25 Pa. Code Chapter 102. Refer to § 203-18 for additional information and guidance concerning timber operations.
J.
Proposed municipal projects are bound to the following requirements
and criteria:
|
Table 203-12-2
| ||||
|---|---|---|---|---|
|
Type of Project
|
Description:
|
Requirements:
| ||
|
Alignments*
|
Change the roadway by either reducing or eliminating horizontal
and vertical curves, or changing the roadway's superelevation.
|
Required: BMP implementation that uses nonstructural and restoration
practices such as:
Street sweeping
Impervious disconnection
Slope roughening
Pavement width reduction
Riparian buffers
Vegetative restoration (including roadside swales)
| ||
|
Pull-offs*
|
New, as part of a larger project or by itself.
| |||
|
Widening*
|
Increase the width of the existing travel lanes (no new lanes
added) and shoulders, or extension of acceleration/deceleration ramps
in existing shoulder areas.
| |||
|
Roadway Restoration
|
Intersection*
|
Nominal channelization of intersections and addition of turning
lanes.
|
Required: Minor practices and BMP implementation that uses low-impact
practices such as:
Preservation of existing vegetation
Minimization of soil compaction
Maintenance of erosion control and any PCSM BMPs
Restoration and stabilization of staging areas
| |
|
Pavement
|
Replace portions, overlay, or mill and resurface the roadway's
surface.
| |||
|
Shoulders
|
Resurface, stabilize, upgrade (dirt or gravel to paved), or
widen the existing shoulders within the existing footprint.
| |||
|
Other
|
Replace and/or repair guide rail, signs, traffic signals, and
drainage systems to their original specifications; various minor safety
improvements.
| |||
|
New Construction
|
Major widening*
|
Addition of one or more travel lanes, including acceleration
and deceleration lanes, to an existing road.
| ||
|
New alignment*
|
New roadway corridor.
| |||
|
Interchange*
|
Reconfiguration of ramps, lane modification within interchange
area, etc.
| |||
|
Municipal facilities
|
New stockpile sites, buildings, or other structures or facilities
not otherwise addressed by the requirements of this section.
| |||
|
*
|
Projects falling into the noted categories and that have the
potential to discharge into surface waters that have existing or designated
HQ or EV uses (including EV wetlands), have impairments due to stormwater,
are connected to combined sewer systems, or have the potential to
have an adverse effect on threatened or endangered species, or critical
habitat for such species, are subject to additional stormwater management
requirements, beyond the requirements listed in the table. The additional
BMP measures that must be considered and implemented for projects
occurring in these areas are as follows:
|
|
Table 202-12-3
| ||
|---|---|---|
|
Constructed wetlands/wet ponds
|
Significant detention of peak flow rates is needed and the contributing
drainage area is large; retrofit existing detention basins are feasible.
| |
|
Permeable pavement
|
Parking lots only.
| |
|
Manufactured products: subsurface storage, water quality inlets,
etc.
|
Subsurface storage products are designed to attenuate peak runoff
events through infiltration and/or discharge rate reduction. Storm
sewer inlet structures or inserts are designed to minimize the discharge
of solids, floatables, and oil/grease pollutants. Regular maintenance
of these products is necessary.
| |
|
Projects occurring in the areas listed above and not previously
bound to such requirements (roadway restoration projects) are also
required to achieve the following targeted outcomes:
|
(1)
For project areas within a release rate district, reduce the postconstruction
runoff peak rate as required by the release rate district in this
chapter. For project areas not within a release rate district, reduce
the postconstruction runoff peak rate to the preconstruction peak
rate for the one-year through one-hundred-year storm events.
(2)
Reduce the postconstruction runoff volume to the preconstruction
runoff volume for the two-year twenty-four-hour storm event and smaller.
A.
The provisions of this chapter are the minimum standards for the
protection of the public.
C.
The municipality will consider waiver requests in accordance with § 203-11C. If an applicant demonstrates to the satisfaction of the governing body of the municipality that any mandatory provision of this chapter is unreasonable or causes unique or undue unreasonableness or hardship as it applies to the proposed project, or that an alternate design may result in a superior result within the context §§ 203-2 and 203-3 of this chapter, the governing body of the municipality upon obtaining the comments and recommendations of the Municipal Engineer and Conservation District may grant a waiver or relief so that substantial justice may be done and the public interest is secured, provided that such waiver will not have the effect of nullifying the intent and purpose of this chapter.
D.
The applicant shall submit all requests for waivers in writing and shall include such requests as a part of the plan review and approval process. The applicant shall state in full the facts of unreasonableness or hardship on which the request is based, the provision or provisions of the Ordinance that are involved, and the minimum waiver or relief that is necessary. The applicant shall state how the requested waiver and how the applicant's proposal shall result in an equal or better means of complying with the requirements of this chapter including but not limited to § 203-11, General requirements.
E.
The municipality shall keep a written record of all actions on waiver
requests. The municipality may charge a fee for each waiver request,
which shall be used to offset the administrative costs of reviewing
the waiver request. The applicant shall also agree to reimburse the
municipality for reasonable and necessary fees that may be incurred
by the Municipal Engineer in any review of a waiver request.
F.
In granting waivers, the municipality may impose reasonable conditions
that will, in its judgment, secure substantially the objectives of
the standards or requirements that are to be modified.
G.
The municipality may grant applications for waivers when the following
findings are made, as relevant:
(2)
That the waiver shall result in an equal or better means of complying
with the intent of this chapter.
(3)
That the waiver is the minimum necessary to provide relief.
(4)
That the applicant is not requesting a waiver based on cost considerations.
(5)
That existing down-gradient stormwater problems will not be exacerbated.
(6)
That runoff is not being diverted to a different drainage area.
(7)
That increased flooding or ponding on off-site properties or roadways
will not occur.
(8)
That potential icing conditions will not occur.
(9)
That increases in peak flow or volume from the site will not occur.
(10)
That erosive conditions due to increased peak flows or volume
will not occur.
(11)
That adverse impact to water quality will not result.
(12)
That increased one-hundred-year floodplain levels will not result.
(13)
That increased or unusual municipal maintenance expenses will
not result from the waiver.
(14)
That the amount of stormwater generated has been minimized to
the greatest extent allowed.
(15)
That infiltration of runoff throughout the proposed site has
been provided where practicable and predevelopment groundwater recharge
protected.
(16)
That peak flow attenuation of runoff has been provided.
(17)
That long-term operation and maintenance activities are established.
(18)
That the receiving streams and/or water bodies will not be adversely
impacted in flood-carrying capacity, aquatic habitat, channel stability
and erosion and sedimentation.
The low-impact development practices provided in the Pennsylvania
BMP Manual shall be used for all regulated activities to the maximum
extent practicable. Water volume controls shall be implemented using
the Design Storm Method in Subsection A or the Simplified Method in
Subsection B below. For regulated activity areas equal or less than
one acre that do not require hydrologic routing to design the stormwater
facilities, this chapter establishes no preference for either methodology;
therefore, the applicant may select either methodology on the basis
of economic considerations, the intrinsic limitations on applicability
of the analytical procedures associated with each methodology, and
other factors.
A.
The Design Storm Method [CG-1 in the Pennsylvania BMP Manual (current
version)] is applicable to any size of regulated activity. This method
requires detailed modeling based on site conditions.
(1)
Do not increase the postdevelopment total runoff volume for all storms
equal to or less than the two-year twenty-four-hour-duration precipitation.
B.
The Simplified Method [CG-2 in the Pennsylvania BMP Manual (current
version)] provided below is independent of site conditions and shall
be used if the Design Storm Method is not followed. This method is
not applicable to regulated activities that disturb greater than one
acre, or for projects that require design of stormwater storage facilities.
For new impervious surfaces:
(1)
Stormwater facilities shall be sized to capture at least the first
two inches of runoff from all new impervious surfaces.
(2)
At least the first one inch of runoff from new impervious surfaces
shall be permanently removed from the runoff flow, i.e., it shall
not be released into the surface Waters of this commonwealth. Removal
options include reuse, evaporation, transpiration, and infiltration.
(3)
Wherever possible, infiltration facilities shall be designed to accommodate
infiltration of the entire permanently removed runoff; however, in
all cases at least the first 1/2 inch of the permanently removed runoff
shall be infiltrated.
A.
Areas not covered by a release rate map from an approved Act 167
stormwater management plan. Postdevelopment discharge rates shall
not exceed the predevelopment discharge rates for the one-, two-,
ten-, twenty-five-, fifty-, and one-hundred-year storms. If it is
shown that the peak rates of discharge indicated by the postdevelopment
analysis are less than or equal to the peak rates of discharge indicated
by the predevelopment analysis for one-, two-, ten-, twenty-five-,
fifty-, and one-hundred-year, twenty-four-hour storms, then the requirements
of this section have been met. Otherwise, the applicant shall provide
additional controls as necessary to satisfy the peak rate of discharge
requirement.
B.
Areas covered by a release rate map from an approved Act 167 stormwater
management plan. For the one-, two-, ten-, twenty-five-, fifty-, and
one-hundred-year storms, the postdevelopment discharge rates will
follow the release rate maps in this chapter. For any areas not shown
on the release rate maps, the postdevelopment discharge rates shall
not exceed the predevelopment discharge rates.
A.
Stormwater runoff from all project sites shall be calculated using
a generally accepted calculation technique that is based on the NRCS
Soil Cover Complex Method. Table 203-16-1 summarizes acceptable computation
methods and the method selected by the qualified professional shall
be based on the individual limitations and suitability of each method
for a particular site.
|
Table 203-16-1
| |||
|---|---|---|---|
|
Acceptable Computation Methodologies for Stormwater Management
Plans
| |||
|
Method
|
Method Developed By
|
Applicability
| |
|
TR-20/WINTR20 (or commercial computer package based on TR-20)
|
USDA NRCS
|
Applicable where use of full hydrology computer model is desirable
or necessary.
| |
|
TR-55/WINTR55 (or commercial computer package based on TR-55)
|
USDA NRCS
|
Applicable for land development plans within limitations described
in TR-55.
| |
|
HEC-HMS
|
US Army Corps of Engineers
|
Applicable where use of full hydrologic computer model is desirable
or necessary.
| |
|
Rational Formula (or commercial computer package based on Rational
Formula)
|
Emil Kuichling (1889)
|
For sites less than 50 acres and with time of concentration
less than 60 minutes (Tc < 60 min), or as approved by the municipality.
| |
|
Other methods such as SWMM, WMS, etc.
|
Varies
|
Other computation methodologies approved by the municipality.
| |
|
Note: Successors to the above methods are also acceptable.
|
B.
All calculations consistent with this chapter using the Soil Cover
Complex Method shall use the appropriate design rainfall depths and
intensities for the various return period storms according to the
approximate center of the proposed development site, in accordance
with the values obtained from the National Oceanic and Atmospheric
Administration's (NOAA) Hydrometeorological Design Studies Center
Precipitation Frequency Data Server (PFDS) at the following location
for the commonwealth of Pennsylvania: http://hdsc.nws.noaa.gov/hdsc/pfds/index.html.
The applicant shall provide documentation of PFDS data location (latitude
and longitude in degrees/minutes/seconds).
C.
All calculations using the Rational Formula shall use rainfall intensities
consistent with appropriate times of concentration for overland flow
and return periods from the NOAA, PFDS website, the Design Storm Curves
from PennDOT Publication 13M, Design Manual Part 2, Chapter 10, and
NOAA Atlas 14.
D.
Times of concentration for overland flow shall be calculated using
the methodology presented in Chapter 3 of Urban Hydrology for Small
Watersheds, NRCS, TR-55 (as amended or replaced from time to time
by NRCS). Times of concentration for channel and pipe flow shall be
computed using Manning's equation. NRCS lag equation divided
by 0.6 as acceptable method for Tc in undeveloped
areas.
E.
In order to reduce stormwater runoff volumes from developed areas
and encourage groundwater recharge, underground basin drains, infiltration
trenches, dry wells, and cisterns are permitted to which roof leaders
may be connected. These drains consist of stone-filled basins that
temporarily store and release water below ground surface. Plans for
such facilities shall be submitted to the municipality for approval,
and the basins shall be used only in those areas where soils, geologic,
and water table conditions permit.
F.
Runoff curve numbers (CN) for both existing and proposed conditions
to be used in the Soil Cover Complex Method shall be obtained from
Table 2-2 of the TR-55 Manual.
H.
All flow assumptions and source of supporting data shall be provided
as part of the overall plan. The municipality reserves the right to
reject any submitted values, despite the source, and to provide a
substitute source for use by the applicant.
I.
Where uniform flow is anticipated, the Manning equation shall be
used for hydraulic computations, and to determine the capacity of
open channels, pipes, and storm sewers. Values for Manning's
roughness coefficient (n) shall be consistent with generally accepted
values from a legitimate and verifiable source. All flow assumptions
and source of supporting data shall be provided as part of the overall
plan. The municipality reserves the right to reject any submitted
values, despite the source, and to provide a substitute source for
use by the applicant. Full flow capacity shall be assumed for closed
conduits. Storm sewer systems consisting of more than three pipe junctions
shall be designed using hydraulic grade line computations.
J.
Outlet structures for stormwater management facilities shall be designed
to meet the performance standards of this chapter using any generally
accepted hydraulic analysis technique or method. The design of any
stormwater detention facilities intended to meet the performance standards
of this chapter shall be verified by routing the design storm hydrograph
through these facilities using the Storage-Indication Method. For
drainage areas greater than 200 acres in size, the design storm hydrograph
shall be computed using a calculation method that produces a full
hydrograph (i.e., TR-20, TR-55, and HEC-HMS).
K.
Stormwater management and related facilities shall be provided:
L.
Storm sewers and related installations.
(1)
When located in undedicated land, they shall be placed within a drainage
easement not less than 20 feet wide as approved by the municipality.
(2)
The use of properly designed, graded, and vegetated drainage channels
is encouraged in lieu of storm sewers in commercial and industrial
areas and, where approved by the municipality, in residential areas.
Such swales shall be designed to not only carry the required discharge
without excessive erosion, but also to increase the time of concentration,
reduce the peak discharge and velocity, and permit the water to percolate
into the soil, where appropriate. Criteria related to the use and
design of drainage swales are as follows:
(a)
The maximum encroachment of water on the roadway pavement along
roadside swales in cut areas shall not exceed half of a through traffic
lane during a ten-year frequency storm of five-minutes duration. Frequent
and/or sustained flooding of the subbase shall be avoided.
(b)
The design of all vegetated channels shall, as a minimum, conform
to the design procedures outlined in the Erosion and Sediment Pollution
Control Program Manual (PA DEP). Inlets shall be provided to limit
road shoulder encroachment and water velocity.
(c)
The side slope for any vegetated drainage channel requiring
mowing of the vegetation shall have a maximum grade of three horizontal
to one vertical on those areas to be mowed. Maximum side slopes for
any vegetated drainage channel shall be two horizontal to one vertical.
(d)
Erosion prevention. All drainage swales shall be designed to
prevent the erosion of the bed and bank areas. Suitable temporary
and/or permanent stabilization during vegetative cover establishment
shall be provided to prevent erosion.
(e)
Storm sewers or drainage swales shall discharge to a detention
or retention basin to attenuate the peak rate and volume, respectively,
of stormwater runoff, except as provided in the plan.
(3)
Storm inlet types and inlet assemblies shall conform to the Pennsylvania
Department of Transportation Standards for Roadway Construction as
approved by the municipality.
(4)
When evidence available to the municipality indicates that existing
storm sewers have sufficient capacity as determined by hydrograph
summation and are accessible, proposed stormwater facilities may connect
to the existing storm sewers so long as the peak rate of discharge
does not exceed the amount permitted by this article.
M.
Downstream analysis. Where deemed necessary by the Municipal Engineer,
the applicant shall submit an analysis of the impacts of detained
stormwater flows on downstream areas within the watershed, established
with the concurrence of the Municipal Engineer. The analysis shall
include hydrologic and hydraulic calculations necessary to determine
the impact of peak discharge modifications of the proposed development
on critical locations such as dams, tributaries, existing developments,
undersized culverts, and flood-prone areas. Review and comment of
the analysis by the Engineer of a downstream municipality shall be
obtained as deemed necessary.
N.
Multiple-use basins. The design and construction of multiple-use
stormwater detention facilities are strongly encouraged. In addition
to stormwater management, where appropriate, facilities allow for
recreational uses including ball fields, play areas, picnic grounds,
etc. Provision for parking facilities within basins and permanent
wet ponds with stormwater management capabilities may also be appropriate.
Prior approval and consultation with the municipality are required
before design. Multiple-use basins shall be constructed so that potentially
dangerous conditions are not created.
O.
Alternative detention facilities. Alternative stormwater detention
facilities including rooftop, subsurface basins or tanks and in-pipe
detention storage, or other approved alternative designs are permitted
as determined by the municipality.
P.
Landscaping of stormwater management facilities. Facilities constructed
with berms or earthen embankments shall not be landscaped along the
top of the impoundment berm, embankment, nor shall other facility
areas constructed from compacted fill materials be landscaped. Heavy
vegetative cover root penetration can cause soil weakening and damage
to facility piping.
A.
All wet basins shall be designed in a manner that seeks to mitigate
the proliferation of mosquito breeding habitats and the potential
spread of the West Nile Virus. This can be accomplished through the
following means:
(1)
The design of a stormwater wetland/wet basin must include the selection
of hydrophytic plant species for their pollutant uptake capabilities
and for not contributing to the potential for vector mosquito breeding.
The establishment of hydrophytic vegetation will promote the population
of the wetland/wet basin by amphibians and other mosquito predators.
In natural wetlands, predatory insects and amphibians are effective
at keeping mosquito populations in check during the larval stage of
development while birds and bats prey on adult mosquitoes. Refer to
Appendix B of the Pennsylvania SWM BMP Manual (current version) for
hydrophytic native plant species lists.
(2)
Aeration fountains and stocked fish can be added to keep larval mosquito
populations in check.
B.
The municipality reserves the right to disapprove any design that
would result in the construction or continuation of a stormwater problem
area.
C.
When the elevation of any existing or proposed entrance to a structure,
including windows, is lower than the elevation of the public cartway
serving that site, a grading plan shall be submitted, reviewed and
approved as part of the SWM approval process for the proposed structure.
D.
No stormwater detention facility shall be placed within 50 feet of
a special geologic feature. No subsurface stormwater conveyance facility
shall be constructed within 50 feet of a special geologic feature
without written permission of the municipality.
E.
Stormwater management facilities located outside of existing or proposed
public rights-of-way shall be located within and accessible by easements
granted to the municipality as follows:
(1)
Access easements. Where proposed stormwater management facilities
are not adjacent to proposed or existing public rights-of-way or are
not accessible due to physical constraints, as determined by the municipality,
a twenty-foot-wide access easement specifying rights of entry shall
be provided commensurate to need. Access easements shall provide for
vehicle ingress and egress on grades of less than 10% for carrying
out inspection or maintenance activities. A permanent fifteen-foot-wide
vehicular access road within the easement(s) shall be provided around
all SWM BMPs, such as ponds and infiltration structures. The access
roads shall connect to a public thoroughfare. The access road (when
applicable) will also provide access at a slope no greater than 20%
to the bottom of all ponds and associated outlet structures. The access
road shall be constructed of either gravel or pavement and maintained
per the maintenance agreement. The municipality reserves the right
to alter the design of the access to any SWM BMP. Vehicle ingress
and egress and access roads are not required for SWM BMPs serving
one single-family residential lot and located on the same lot they
serve.
(2)
Maintenance easements. The maintenance easement must be located 20
feet outside of the footprint for the stormwater facility and appurtenances.
Maintenance easements are not required for SWM BMPs serving one single-family
residential lot and located on the same lot they serve.
(3)
Easements shall state that no trees, shrubs, structures, excavation,
placement of fill, or regrading are to be performed within the easement
without written approval from the municipality upon review by the
Municipal Engineer. Upon approval of the municipality, such landscaping
may be placed in maintenance easements, provided it does not impede
access.
(4)
Whenever practicable, easements shall be parallel to width and linked
to property lines of the subdivision.
(5)
All easement agreements shall be recorded with a reference to the
recorded easement indicated on the site plan. The format and content
of the easement agreement shall be reviewed and approved by the municipality
and Solicitor.
F.
In order to promote overland flow and infiltration, root drains shall
not discharge directly to streets or storm sewers. Roof drains may
discharge directly to streets or storm sewers when deemed necessary
by the municipality. Under no circumstances shall roof drains discharge
directly to sanitary sewer systems.
G.
Additional BMP measures in environmentally sensitive areas.
(1)
Projects that have the potential to discharge into surface waters
that have existing or designated HQ or EV uses (including EV wetlands),
have impairments due to stormwater, are connected to combined sewer
systems, or have the potential to have an adverse effect on threatened
or endangered species, or critical habitat for such species, are subject
to additional BMP measures that must be considered and implemented
for projects occurring in these more environmentally sensitive areas:
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Constructed wetlands/wet ponds
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Significant detention of peak flow rates is needed and the contributing
drainage area is large; retrofit existing detention basins or construct
new in open median or interchange areas.
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Permeable pavement
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Limited to park-and-ride sites and parking lots.
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Manufactured products: subsurface storage, water quality inlets,
etc.
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Subsurface storage products are designed to temper peak runoff
events through infiltration and/or discharge rate reduction. Storm
sewer inlet structures or inserts are designed to minimize the discharge
of solids, floatables, and oil/grease pollutants. Regular maintenance
of these products is necessary and is an important factor in assessing
the feasibility of using one of these products.
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(2)
Proposed infiltration BMPs within two miles on either side of surface
water supply areas or surface waters that have existing or designated
HQ or EV uses (including EV wetlands) must be designed and constructed
to provide maximum pollutant removal prior to the runoff being infiltrated
or discharged to the receiving stream. PA DEP defines the following
zones around such waters:
(a)
Zone A: represents a one-fourth-mile buffer on either side of
the river or stream extending from the area 1/4 mile downstream of
the intake upstream to the five-hour time-of-travel (TOT) (Pennsylvania
Department of Environmental Protection, 2006).
(b)
Zone B: represents a two-mile buffer on either side of the water
body extending from the area 1/4 mile downstream of the intake upstream
to the twenty-five-hour TOT. (Pennsylvania Department of Environmental
Protection, 2006).
(c)
Zone C: the remainder of the watershed area (Pennsylvania Department
of Environmental Protection, 2006).
H.
Groundwater supply protection.
(1)
Zone 1: the innermost protective zone surrounding a well, spring,
or existing infiltrative gallery. Zone 1 is the area within a radius
of 400 feet around a community or public water supply source unless
information is presented supporting a reduction of this requirement.
Proposed infiltration BMPs are not permitted within Zone 1 protection
areas (Pennsylvania Department of Environmental Protection, 2006).
(2)
Zone 2: the capture zone that encompasses the area of the aquifer
through which it supplies water to a well, spring, or existing infiltration
gallery. Zone 2 is one-half-mile radius around a community or public
water supply source unless more extensive hydrogeological testing
is done. Extreme care should be used when implementing infiltration
BMPs in Zone 2 areas. Pretreatment measures must be used to filter
and diminish pollutants (Pennsylvania Department of Environmental
Protection, 2006).
(3)
Zone 3: the area outside Zone 2 that contributes significant recharge
to the capture zone aquifer in Zone 2 (Pennsylvania Department of
Environmental Protection, 2006). Use of infiltration BMPs is not restricted.
(4)
Infiltration BMPs are not permitted within a radius of 50 feet from
privately owned wells and water sources serving noncommunity supply
systems (Pennsylvania Department of Environmental Protection, 2006).
It is not the intention for this section to serve as an ordinance
or regulatory document governing the practice of timber harvesting/silviculture
activities. However, the intent of this section and the included guidelines
is to address specific stormwater management issues related to or
caused by such timber harvesting activities. These regulations shall
not be considered a timber harvesting ordinance, nor do they relieve
the applicant from meeting any additional timber harvesting regulations
already in place. The municipality, at its own discretion, may choose
to enact any new or enforce any existing ordinance directly related
to timber harvesting.
A.
Logging operators shall address and comply with all applicable standards
for erosion and sedimentation control and stream crossing regulations
under 25 Pennsylvania Code, Chapter 102, Erosion Control Rules and
Regulations, issued pursuant to the Clean Stream Law.[1], and 25 Pennsylvania Code, Chapter 105, Dam and Waterway
Management Rules and Regulations, issued pursuant to the Dam Safety
and Encroachments Act[2] Any additional governing or amended regulations shall
hereby govern all logging plans, including those mentioned by the
regulatory authorities listed or by any other entity garnishing such
authoritative and administrative powers.
B.
Logging operators shall address and comply with all applicable standards
for stormwater management as set forth in the Stormwater Management
Plan of Lawrence County, and any regulations, stormwater management
plans and ordinances issued or enacted pursuant thereto.
C.
All logging operations shall be conducted in strict adherence with
PA DEP Document 3930-BK-DEP4016 (Revised 06/2007) or the most recent,
amended version.
D.
At a minimum, logging operators shall address each of the following:
(1)
Design of the logging road system, taking into account its influence
on surface runoff, this includes haul roads, skid roads, and skid
trails.
(2)
Water control structures.
(3)
Stream crossings and potential wetland impacts.
(4)
Log landings.
(5)
Maintenance.
(6)
Public road use.
(7)
Retirement of logging roads, log landings, stream crossings, structures,
etc., and restoration of the same.
E.
Controlling erosion on logging road systems is required.
(1)
A functional drainage system of culverts, dips, bridges, turnouts,
and out-sloping or in-sloping roads to handle stormwater runoff.
(2)
Keep road reasonably free of ruts, curbs and logging debris that
may prevent water from moving freely into drainage structures.
(3)
Reduce or eliminate traffic on haul roads, skid trails and landings
during wet weather and during periods when frozen roads are thawing.
(4)
The erosion and sediment pollution control plan must show how haul
roads, skid roads, and landings are proposed to be retired.
