[Ord. 2013-499, 7/10/2013]
1.
Permanent Stormwater Management Standards. The following standards
shall be used to develop the stormwater management system:
A.
Standard 1: After site development, there shall be no increase in
the volume of stormwater runoff being discharged for up to the two-year
frequency rainfall, predevelopment to postdevelopment
B.
Standard 2: After site development and assuming full compliance with
Standard 1, the peak rate of stormwater discharges from the site shall
be as follows:
|
Design Storm Postdevelopment
|
Design Storm Predevelopment
|
|---|---|
|
2-year
|
1-year
|
|
10-year
|
2-year
|
|
25-year
|
25-year
|
|
50-year
|
50-year
|
|
100-year
|
100-year
|
C.
Standard 3: Under certain conditions, the Borough, upon recommendation
of the Borough Engineer, may impose the following additional restrictions
on stormwater discharges:
(1)
Peak discharge may be further restricted when it can be shown
that a probable risk to downstream structures or unique natural areas
exists or that existing severe flooding problems may be further aggravated.
(2)
Measures may be imposed to protect against ground- or surface
water pollution where the type of business activity conducted at the
site may result in significant nonpoint source pollution ("hot spots")
or the nature of the soils or bedrock underlying a stormwater management
structure presents substantial risk of contamination (e.g., limestone
formations). Special measures to be followed in these cases shall
be provided by the Borough Engineer.
(3)
Where groundwater yields are very low or where a groundwater
supply already is heavily used, the Borough may require that the entire
volume of the two-year-frequency rainfall (3.2 inches in 24 hours)
be retained and infiltrated.
D.
Standard 4: Significant loadings of nonpoint source pollutants shall
not be discharged into either surface water or groundwater. "Significant"
shall be defined as resulting in an increase greater than 10% of existing
background concentrations of all water quality parameters of consequence
identified in federal and state criteria for the watershed. In particular,
nutrients (nitrate and total phosphorus), metals (cadmium and lead),
total petroleum hydrocarbons (PH) and synthetic organic compounds
identified by the U.S. Environmental Protection Agency (EPA) as toxic
or hazardous substances must be controlled. If the volume and peak
rate standards above (Standards 1 and 2) are met, then water quality
impacts are assumed to be adequately controlled. If the volume standard
(Standard 1) above cannot be achieved, then a water impact analysis
must be performed, at the direction of the Borough Engineer and at
the applicant's expense, confirming prevention of any significant
increase in nonpoint source pollution, with particular focus on the
pollutants discussed above. Both structural and nonstructural (preventive)
measures are to be considered for reduction and prevention of nonpoint
source pollution.
2.
Stormwater Management Calculation Methods.
A.
In establishing the antecedent conditions for calculating runoff
prior to land disturbance, the following assumptions shall apply:
(1)
Average antecedent moisture conditions;
(2)
A Type II distribution storm;
(3)
Woodland shall be used as the prior condition for those portions
of the site having trees of greater than six inches caliper at 4.5
feet above the average grade at the base of the tree or where such
trees existed within three years of application;
(4)
Meadow shall be used for all other areas, including areas of
existing cultivation;
(5)
In performing the TR-55 calculations, all those areas to be
disturbed during construction shall be assumed to be reduced one hydrologic
soil group category level during postdevelopment runoff calculations
(i.e., HSG B is reduced to HSG C, and so forth).
B.
In all plans and designs for stormwater management systems and facilities
submitted to the Borough Engineer for approval, stormwater peak discharge
and runoff shall be determined through the use of the Soil Cover Complex
Method as set forth in Urban Hydrology for Small Watersheds, Technical
Release No. 55, with specific attention given to antecedent moisture
conditions, flood routing, and peak discharge specifications included
therein and in Hydrology National Engineering Handbook, Section 4,
both by the U.S. Department of Agriculture, Natural Resources Conservation
Service (Soil Conservation Service). Note that use of TR-55 with many
of the natural system-based approaches and practices recommended by
this Part requires that calculations be performed on a detailed small
subarea basis. The Borough Engineer may permit the use of the Rational
Method for calculation of runoff on land developments of five acres
or less and for the design of storm structures.
C.
All calculations consistent with this Part using the Soil Cover Complex
Method shall use the appropriate design rainfall depths for the various
return period storms according to the region for which they are located
as presented in the NOAA Atlas 14, most recent revision.
[Amended by Ord. 2014-505, 2/12/2014]
D.
All calculations using the Rational Method shall use rainfall intensities consistent with appropriate times of concentration for overland flow and return periods from the design storm curves from Pennsylvania Department of Transportation design rainfall curves, Design Manual, Part 2, Chapter 10, most recent revision.
E.
Runoff curve numbers (CN) for both existing and proposed conditions
to be used in the Soil Cover Complex Method shall be obtained from
Urban Hydrology for Small Watersheds, as prepared by the Soil Conservation
Service, most recent revision.
F.
Runoff coefficients (c) for both existing and proposed conditions
for use in the Rational Method shall be obtained from Table 1 as shown
below.
|
Table 1
Runoff Coefficients for the Rational Method by Hydrologic
Soil Group and Slope Range
| ||||||
|---|---|---|---|---|---|---|
|
*HSG
|
B
|
HSG
|
C
|
HSG
|
D
| |
|
Type of Land Use
|
0-6%
|
6%+
|
0-6%
|
6%
|
0-6%
|
6%+
|
|
Cultivated land
|
0.41
|
0.47
|
0.45
|
0.52
|
0.49
|
0.57
|
|
Pasture
|
0.34
|
0.39
|
0.40
|
0.46
|
0.46
|
0.53
|
|
Meadow
|
0.25
|
0.30
|
0.30
|
0.35
|
0.35
|
0.40
|
|
Woodland
|
0.20
|
0.24
|
0.25
|
0.30
|
0.30
|
0.36
|
|
Lawn
|
0.30
|
0.33
|
0.35
|
0.39
|
0.40
|
0.45
|
|
Gravel
|
0.88
|
0.91
|
0.90
|
0.93
|
0.92
|
0.95
|
|
Impervious
|
0.95
|
0.95
|
0.95
|
0.95
|
0.95
|
0.95
|
|
*Site area containing areas of Hydrologic Soil Group A should
utilize the values shown in the Hydrologic Soil Group B column.
|
G.
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 Table 2 of this Part.
|
Table 2
Manning Roughness Coefficients
Roughness Coefficients (Manning's "n") for Overland/Sheet
Flow
(From U.S. Army Corps of Engineers and NRCS TR-55)
| ||
|---|---|---|
|
Surface Description
|
n
| |
|
Dense growth
|
0.4 — 0.5
| |
|
Pasture
|
0.3 — 0.4
| |
|
Lawns
|
0.2 — 0.3
| |
|
Bluegrass sod
|
0.2 — 0.5
| |
|
Short grass prairie
|
0.1 — 0.2
| |
|
Sparse vegetation
|
0.05 — 0.13
| |
|
Bare Clay — Loam Soil (eroded)
|
0.01 — 0.03
| |
|
Concrete/asphalt
| ||
|
Very shallow depths (less than 1/4 inch)
|
0.10 — 0.15
| |
|
Small depths (1/4 inch to several inches)
|
0.05 — 0.10
| |
|
Table 2
Manning Roughness Coefficients
| |
|---|---|
|
Fallow (no residue)
|
0.05
|
|
Cultivated soils
| |
|
Residue cover less than or equal to 20%
|
0.06
|
|
Residue cover greater than 20%
|
0.17
|
|
Grass
| |
|
Dense grasses
|
0.24
|
|
Bermuda grass
|
0.41
|
|
Range (natural)
|
0.13
|
|
Woods (light underbrush)
|
0.40
|
|
Roughness coefficients (Manning's "n") for channel flow
| |
|
Reach Description
|
n
|
|
Natural stream, clean, straight, no rifts or pools
|
0.03
|
|
Natural stream, clean, winding, some pools or shoals
|
0.04
|
|
Natural stream, winding, pools, shoals, stony with some weeds
|
0.05
|
|
Natural stream, sluggish deep pools and weeds
|
0.07
|
|
Natural stream or swale, very weedy or with timber underbrush
|
0.10
|
|
Concrete pipe, culvert or channel
|
0.012
|
|
Corrugated metal pipe
|
0.012 — 0.027*
|
|
* Depending upon type, coating and diameter.
|
3.
Specific Infiltration System Design Criteria.
A.
Infiltration devices shall be selected based on suitability of soils
and site conditions. Measures may include underground infiltration
beds located under paved areas, vegetated infiltration beds, swales
and trenches, or other seepage structures as recommended in the Pennsylvania
Stormwater BMP Manual (2006), most recent edition, or other guidance
documents approved by the Borough. The infiltration device type and
construction details shall be approved by the Borough Engineer.
B.
Soil infiltration tests shall be performed and witnessed by the Borough
Engineer or geotechnical consultant, for all proposed infiltration
areas; these tests shall include evaluation of selected soil horizons
by deep pits and percolation measurements. Results of the on-site
testing shall be submitted to the Borough Engineer for review and
approval. The soil infiltration rate of discharge from the infiltration
area and proposed design shall be based upon these measurements.
C.
The lowest elevation of the infiltration area shall be at least two
feet above the seasonal high water table (SHWT) and bedrock, except
in the case of limestone formation, in which case the distance shall
be three feet.
D.
Any roof drains which discharge to infiltration systems must contain
appropriate measures, such as leaf traps and cleanouts, taken to prevent
clogging by vegetation.
E.
All infiltration systems shall have appropriate positive overflow
controls to prevent storage within one foot of the finished surface
or grade.
F.
Infiltration systems shall have a minimum setback of 15 feet from
all structures that do not include a basement. Care shall be taken
to prevent any seepage into subgrade structures.
G.
All infiltration systems shall be designed to infiltrate the stored
volume within 72 hours.
H.
All surface inflows shall be treated prior to direct discharge into
the infiltration system; accumulated sediment reduces stormwater storage
capacity and ultimately clogs the infiltration mechanism.
I.
During site construction, all recharge system components shall be
protected from compaction due to heavy equipment operation or storage
of fill or construction material. Recharge areas shall also be protected
from sedimentation. All areas designated for recharge shall not receive
runoff until the contributory drainage has achieved final stabilization.
J.
The following procedures and materials shall be required during the
construction of all subsurface facilities:
(1)
Excavation for the infiltration facility shall be performed
with equipment which will not compact the bottom of the seepage bed/trench,
or like facility.
(2)
The bottom of the bed and/or trench shall be scarified prior
to the placement of aggregate.
(3)
Only clean aggregate, free of fines, shall be allowed.
(4)
The top and sides of all seepage beds, trenches, or like facilities
shall be covered with drainage filtration fabric. Fabric shall meet
the specifications of PennDOT Publication 408, Section 735, Construction
Class 1.
(5)
Perforated distribution pipes connected to centralized catch
basins and/or manholes with provision for the collection of debris
shall be provided in subsurface infiltration facilities. The perforated
pipes shall distribute stormwater throughout the entire seepage bed/trench,
or like facility.
K.
All infiltration facilities which service more than one lot and are
considered a common or shared facility shall have an easement granted
to the Borough for future access, inspection, maintenance and repair,
if determined by the Borough to be necessary upon advice of the Borough
Solicitor.
4.
Additional Stormwater Detention/Retention Facilities Design Requirements.
A.
The following setbacks are required for stormwater management facilities:
(1)
Stormwater retention or detention basins shall be located at
least 50 feet from any structure, whether existing or proposed.
(2)
Stormwater retention or detention basins shall be located at
least 50 feet from any property boundary or right-of-way.
(3)
Stormwater retention or detention basins shall be located at
least 50 feet from existing wetlands, or the banks of existing streams,
unless other agency regulations require additional setback distances.
(4)
Recharge systems located on the downslope side of a structure
shall be located at least 15 feet from any basement wall and 50 feet
from wastewater treatment areas.
(5)
Recharge systems located on the upslope side of a structure
shall be located at least 100 feet from any basement wall.
(6)
Any recharge system designed to handle runoff from any commercial
or industrial impervious parking or outside storage area shall be
a minimum of 50 feet from any water supply well or any wastewater
treatment area.
B.
Riser. A riser or other acceptable outfall structure shall be provided
at the outlet of all detention basins. The riser shall be constructed
of precast or poured-in-place concrete with controlled orifices. The
height of the riser structure shall be designed such that no flow
enters the top of the riser for the one-hundred-year frequency event.
A trash rack or similar appurtenance shall be provided to prevent
debris from entering the riser. All risers shall have a concrete base
attached with a watertight connection. The base shall extend three
feet below bottom of basin elevation. All riser structure connections
are to be watertight.
C.
Landscaping. All stormwater control systems, whether existing or
proposed, shall be planted to effectively naturalize areas so as to
become an integral and harmonious element in the local landscape.
No trees shall be planted in dams more than 15 feet high.
D.
Emergency Spillway. Whenever possible, the emergency spillway for
detention basins shall be constructed on undisturbed ground. Emergency
spillways shall be designed according to the Soil Conservation Service
Engineering Field Manual. All emergency spillways shall be constructed
so that the detention basin berm is protected against erosion. The
minimum capacity of all emergency spillways shall be such that the
capacity of the emergency spillway equals the peak flow rate from
the one-hundred-year design storm. Emergency spillway erosion protection
shall extend along the upstream and downstream berm embankment slopes.
The upstream edge of the emergency spillway shall be considered a
minimum of two feet below the spillway crest elevation. The downstream
edge of the spillway shall, at minimum, extend to the toe of the berm
embankment. The emergency spillway shall not discharge over earthen
fill and/or easily erodible material.
E.
Antiseep Collars. Antiseep collars shall be installed around the
basin outfall pipe barrel within the normal saturation zone of the
detention basin berms. The antiseep collars and their connections
to the pipe barrel shall be watertight. The antiseep collars shall
extend a minimum of two feet beyond the outside of the basin outfall
pipe barrel. The maximum spacing between collars shall be 14 times
the minimum protection of the collar measured perpendicular to the
pipe. The antiseep collars shall be a minimum of one foot in thickness.
F.
Freeboard. Freeboard is the difference between the design flow elevations
in the emergency spillway and the top of the settled detention basin
embankment. The minimum freeboard shall be one foot.
G.
Slope of Detention Basin Embankment. The maximum slope of earthen
detention basin embankments shall meet the requirements contained
in this Chapter. Whenever possible, the side slopes and basin shape
shall be amenable to the natural topography. Straight side slopes
and rectangular basins shall be avoided.
H.
Width of Berm. The minimum top width of detention basin berms shall
be 10 feet.
I.
Slope of Basin Bottom. In order to insure proper drainage of the
detention basin, a minimum grade of 2% shall be maintained for all
sheet flow. A minimum grade of 1% shall be maintained for all channel
flow. These standards do not apply if the basin is to be utilized
for infiltration or as a biofiltration device, subject to the prior
approval of the Borough Engineer.
J.
Energy Dissipaters. Energy-dissipating devices (riprap, end sills,
etc.) shall be placed at all basin outlets. Any pipe or other component
which discharges directly into the basin shall be equipped with energy-dissipating
devices and shall outlet into the bottom of the basin.
K.
Landscaping and Grading of Detention Basins. All landscaping and
grading standards shall be as follows:
(1)
Cuts. No excavation shall be made with a cut face steeper than
three horizontal to one vertical (3:1). Retaining walls shall be required
if a stable slope cannot be maintained. Any retaining wall design
must be approved by the Borough Engineer. The toe of the slope or
headwall of any cut must be located a minimum of five feet from all
property lines.
(2)
Fills. No fills shall be made which create any exposed surfaces
steeper in slope than three horizontal to one vertical (3:1). The
top of any fill or toe of the slope of any fill shall be located five
feet from any property line with the exception of a downstream property
line where the toe of the embankment shall be placed a sufficient
distance to allow for energy-dissipating devices, but in no case less
than five feet.
(3)
Planting Requirements. All areas shall be planted to effectively
naturalize the areas to become an integral and harmonious element
in the natural landscape. Naturalized areas are encouraged to reduce
the need for regular mowing activities and increase quality of habitat
diversity. Seasonal mowing of the interior slopes of the detention/retention
basins for maintenance is permitted. Mowed turf areas shall not be
proposed within the interior of detention/retention basins.
(4)
Drainage Channels and Retention Areas. All storm drainage channels
and retention areas, whether existing or proposed, shall be graded
and planted to effectively naturalize areas so as to become an integral
and harmonious part of the landscape by contour and type of plant
material employed.
(5)
Fence or Screening. A fence or suitable vegetation screen shall
be provided around all detention basins as required and approved by
the Borough Engineer. All vegetative screening shall be at least three
feet in height at installation. All vegetative screening shall provide
a barrier to prevent entrance to the detention basin area.
L.
Basin Location.
(1)
Whenever a basin will be located in an area underlain by limestone,
a geological evaluation of the proposed location shall be conducted
to determine susceptibility to sinkhole formations. The design of
all facilities over limestone formations shall include measures to
prevent groundwater contamination and, where necessary, sinkhole formation.
The Borough may require the installation of an impermeable liner in
detention basins. A detailed hydrogeologic investigation may be required
by the Borough.
(2)
The municipality may require the developer to provide safeguards
against groundwater contamination for uses which may cause groundwater
contamination, should there be a mishap or spill.
(3)
It shall be the developer's responsibility to determine whether
the site is underlain by limestone. The following note shall be attached
to all drainage plans and signed and sealed by the developer's engineer/surveyor/landscape
architect/geologist:
__________________________, represents that the proposed detention
basin is/is not (circle one) underlain by limestone.
M.
Basin Outfall Pipe. All basin outfall pipes shall contain O-ring-style
joints as utilized by and meeting the requirements of the Pennsylvania
Department of Transportation.
N.
Easements in form and substance acceptable to the Borough Solicitor
shall be provided for all basins, storm pipes and related facilities
not located within the public street right-of-way.
5.
Stormwater Drainage System Design Requirements.
A.
Design Flow Rate.
(1)
The storm drain system shall be designed to carry a fifty-year
peak flow rate and a one-hundred-year peak flow rate at the sump area.
The design fifty-year peak flow rate into each inlet shall be indicated
on the stormwater management plan. The flow rate shall be determined
by the rational formula:
|
Q
|
=
|
CIA
|
|
Where
| ||
|
Q
|
=
|
Peak runoff rate, cubic feet per second (CFS).
|
|
C
|
=
|
Runoff coefficient equal to the ratio of the runoff rate to
the average rate of rainfall over a time period equal to the time
of concentration.
|
|
I
|
=
|
Average rainfall intensity to inches per hour for a time equivalent
to the time of concentration.
|
|
A
|
=
|
Drainage area in acres.
|
(2)
Appropriate values for runoff coefficients and rainfall intensities
are found in § 19-401.2 of this Part entitled "Stormwater
Management Calculation Methods."
B.
Overflow System. An overflow system shall be provided to carry flow
to the detention basin when the capacity of the storm drainpipe system
is exceeded. The overflow system shall be of sufficient capacity to
carry the difference between the one-hundred-year and the fifty-year
peak flow rates.
C.
Inlet Capacity. All inlets shall be designed to accommodate the fifty-year
peak flow rate. Inlets shall be spaced to limit the gutter spread
to no more than 1/3 of the width of the travel lane during the fifty-year
storm. Inlets shall be sumped no more than one inch in depth at gutter
face. The capacity of all C-, M-, or S-type inlets shall be determined
from the following source:
|
Commonwealth of Pennsylvania
|
|
Department of Transportation
|
|
Design Manual, Part 2 – Highway Design
|
D.
Straight Pipe Selections. Wherever possible, all storm drainpipes
shall be designed to follow straight courses. No angular deflections
of stormwater pipe sections shall be permitted. No vertical curves
shall be permitted in the storm drainpipe system.
E.
Minimum Grade and Size. All storm drainpipes shall be designed to
maintain a minimum grade of 1/2%. All storm pipes shall have a minimum
inside diameter of 15 inches, except that pipes under a twenty-five-foot
or greater fill shall not be less than 24 inches.
F.
Pipe Material and Thickness. All storm sewers shall be constructed
of HDPE or reinforced concrete material which meets PennDOT requirements.
G.
Pipe Capacity. The capacity of all pipe culverts shall, at a minimum,
provide the required capacity to convey the twenty-five-year storm
event.
H.
Pipe Arches. Where headroom is restricted, equivalent pipe arches
may be used in lieu of circular pipes.
I.
Allowable Headwater Depth. At all inlets or manholes, the maximum
allowable headwater depth shall be one foot below the top of the inlet
grate of the manhole cover.
J.
Horizontal Pipe Deflections. A manhole or inlet shall be provided
at all horizontal deflections in the storm pipe system.
K.
Minimum and Maximum Cover. A minimum of 24 inches of cover shall
be maintained over all storm drainpipes. The top of storm drainpipes
shall be at least 1/2 foot below subgrade elevation.
L.
Diversion or Runoff. All storm drainpipes shall be designed to carry
the runoff into a detention basin or similar facility utilized to
control the rate of runoff. No discharge at the top or side of basin
embankments shall be permitted.
M.
Culverts and Drainage Channels.
(1)
Design Flow Standards. All culverts and drainage channels shall
be designed to carry a flow rate equal to a one-hundred-year, twenty-four-hour
storm (Soil Conservation Service, Technical Release No. 55).
(2)
Erosion Prevention. All drainage channels shall be designed
to prevent the erosion of the bed and bank areas. The flow velocity
in all vegetated drainage channels shall not exceed three feet per
second to prevent erosion unless special provisions are made to protect
banks and channel bottoms against erosion. Suitable bank stabilization
shall be provided where required to prevent erosion of the drainage
channels. Where storm sewers discharge into existing drainage channels
at an angle greater than 30° from parallel with the downstream
channel flow, the far side bank shall be stabilized by the use of
riprap or masonry and/or concrete walls. The stabilization shall be
designed to prevent erosion and frost heave under and behind the stabilizing
media.
(3)
Maximum Side Slope. Any vegetated drainage channel requiring
mowing of the vegetation shall have a maximum grade of three horizontal
to one vertical (3:1) of those areas to be mowed.
(4)
Design Standard. Because of the critical nature of the vegetated
drainage channels, the design of all vegetated channels shall, at
a minimum, conform to the design procedures outlined in the PADEP
manuals. Several acceptable sources that outline procedures for nonvegetated
drainage channels include, without limitation, the following:
(5)
References to publications and source documents in this subsection
shall be deemed to include any amendments and revisions thereof.
6.
Standards During Land Disturbance.
A.
During earth disturbance activities, when significant sediment can be contained in runoff, this runoff shall be controlled prior to entering any proposed infiltration area. Specific requirements are outlined in § 19-402, Erosion and Sediment Control During Regulated Earth Disturbance Activities.
B.
Peak discharges and discharge volumes from the site shall comply
with the requirements of this Part, with the following additions:
(1)
For purposes of calculating required detention storage during
land disturbance, peak discharges and discharge volumes shall be calculated
based upon the runoff coefficients for bare soils during the maximum
period and extent of disturbance. Controls shall insure that the difference
in volumes and rates of peak discharge before disturbance and during
shall not exceed those peak discharges and discharge volumes noted
in this Chapter. Detention storage during the period of land disturbance
and prior to establishment of permanent cover may require additional
facilities on a temporary basis. Such measures shall be located so
as to preserve the natural soil infiltration capacities of the planned
infiltration bed areas.
(2)
Wherever soils, topography, cut and fill or grading requirements,
or other conditions suggest substantial erosion potential during land
disturbance, the Borough, as recommended by the Borough Engineer,
may require that the entire volume of all storms up to a two-year
storm from the disturbed areas be retained on site and that special
sediment trapping facilities (such as check dams, etc.) be installed.
C.
Sediment in runoff water shall be trapped in accordance with criteria
of the County Conservation District and PADEP and removed through
means approved by the Borough Engineer to assure proper functioning
and adequate capacity in the basins or traps.
D.
Procedures shall be established by the applicant for protecting soils
or geologic structures with water supply potential from contamination
by surface water or other disruption by construction activity.
[Ord. 2013-499, 7/10/2013]
1.
No regulated earth disturbance activities within the Borough shall
commence until plan approval by the Montgomery County Conservation
District and the Borough Engineer of an erosion and sediment control
plan for construction activities.
2.
The applicant shall comply with all DEP regulations that require
an erosion and sediment control plan for any earth disturbance activity
of 5,000 square feet or more in accordance with 25 Pa. Code § 102.4(b).
3.
The applicant shall comply with the provisions of 25 Pa. Code Chapter
92a, which require a DEP NPDES construction activities permit for
regulated earth disturbance activities.
4.
Evidence of any necessary permit(s) for regulated earth disturbance
activities from the appropriate DEP regional office or County Conservation
District shall be provided to the Borough prior to the commencement
of any work.
5.
A copy of the erosion and sediment control plan and any required
permit, as required by DEP regulations, shall be available at the
project site at all times.
6.
No construction machinery that leaks fluids (oils, antifreeze, coolants,
hydraulic fluids) shall be permitted to be operated during any earth
disturbance activity; if such equipment develops a leak during operation,
it shall immediately be shut down and the leak fixed. All fluids leaked
onto the ground surface, and the contaminated ground surface itself,
shall be cleaned up and disposed of properly and in compliance with
applicable law to eliminate the possibility of stormwater contamination.
[Ord. 2013-499, 7/10/2013]
1.
No regulated earth disturbance activities within the Borough shall
commence until approval by the Borough of a plan which demonstrates
compliance with state water quality requirements after construction
is complete.
2.
The BMPs shall be designed, implemented and maintained to meet state
water quality requirements and any other more stringent requirements
as determined by the Borough.
3.
To control postconstruction stormwater impacts from regulated earth
disturbance activities, state water quality requirements shall 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. Based on the system types and specifications set forth in
the Pennsylvania Handbook of Best Management Practices for Developing
Areas, published by the Commonwealth of Pennsylvania, as amended and
updated, this may be achieved by one or more of the following:
A.
Infiltration: replication of preconstruction stormwater infiltration
conditions;
B.
Treatment use of water quality treatment BMPs to ensure filtering
out of the chemical and physical pollutants from the stormwater runoff;
and
C.
Stream bank and streambed protection: management of volume and rate
of postconstruction stormwater discharges to prevent physical degradation
of receiving waters (e.g., from scouring).
4.
The applicant shall comply with all DEP regulations that are intended
to ensure design, implementation and maintenance of BMPs that control
runoff from new development and redevelopment after regulated earth
disturbance activities are complete. These requirements shall include
the implementation of postconstruction stormwater BMPs and the assurance
of long-term operations and maintenance of those BMPs.
5.
Evidence that all necessary permit(s) for regulated earth disturbance activities have been issued by the appropriate agencies shall be provided to the Borough. The issuance of an NPDES construction permit (or permit coverage under the statewide general permit. [PAG-2]) shall be deemed to satisfy the requirements of § 19-402.
7.
Commercial and industrial properties shall demonstrate compliance
with the NPDES (40 CFR Part 122) as administered by DEP. Copies of
stormwater pollution prevention plans (SWPPP) and monitoring reports
shall be provided to the Borough.
[Ord. 2013-499, 7/10/2013]
1.
No regulated earth disturbance activities within the Borough shall
commence until a BMP operation and maintenance plan for the project
site (also known as a "stormwater management plan"), acceptable to
the Borough Engineer, shall have been approved by Borough Council,
which shall describe how the permanent (e.g., postconstruction) stormwater
BMPs will be properly operated and maintained.
2.
The following items shall be included in the BMP operation and maintenance
plan:
A.
Map(s) of the project area, in a form that meets the requirements
for recording at the Office of the Recorder of Deeds of Montgomery
County, and shall be submitted on twenty-four-inch-by-thirty-six-inch
or thirty-inch-by-forty-two-inch sheets. The contents of the maps(s)
shall include, but not be limited to:
(1)
Clear identification of the location and nature of permanent
stormwater BMPs;
(2)
The location of the project site relative to highways, municipal
boundaries or other identifiable landmarks;
(3)
Existing and final contours at intervals of two feet, or others
as appropriate;
(4)
Existing streams, lakes, ponds, or other bodies of water within
the project site area;
(5)
Other physical features, including wetlands, sinkholes, streams,
existing drainagecourses, and areas of natural vegetation to be preserved;
(6)
The locations of all existing and proposed utilities, sanitary
sewers, and waterlines within 50 feet of the property lines of the
project site;
(7)
Proposed final changes to the land surface and vegetative cover,
including the type and amount of impervious area that will be added;
(8)
Proposed final structures, roads, paved areas, and buildings;
and
(9)
A fifteen-foot-wide access easement around and from all stormwater
BMPs to provide access, ingress to and egress from a public right-of-way.
B.
A description of how and when each permanent stormwater BMP will
be operated and maintained, and the identity of the person(s) responsible
for operations and maintenance.
C.
The name of the project site, the name and address of the owner of
the property, and the name of the individual or firm preparing the
Stormwater Management Plan.
D.
A statement, signed by the landowner, acknowledging that the stormwater
BMPs are fixtures that shall not be altered or removed without the
prior written approval of the Borough upon advice of the Borough Engineer.
E.
The Stormwater Management Plan shall include the following block
for Borough use:
"__________", on this date __________ has reviewed and hereby
certifies that the stormwater management plan meets all design standards
and criteria of Red Hill Borough Ordinance No. 2013-499.
F.
Red Hill Borough Council shall not approve any stormwater management
plan that is deficient in meeting the requirements of this Chapter.
When a stormwater management plan is found to be deficient, Borough
Council may disapprove the submission and require the submission of
a new stormwater management plan, or in the case of minor deficiencies
as determined by the Borough in its sole discretion, Borough Council
may accept the resubmission of the plan with modifications.
