[Added 5-16-2005 by Ord. No. 331]
The Board of Supervisors of Franconia Township
finds that:
A.
Stormwater runoff from lands modified by human activities
threatens public health and safety by causing decreased infiltration
of rainwater and increased runoff flows and velocities, which overtaxes
the carrying capacity of existing streams and storm sewers, and greatly
increases the cost to the public to manage stormwater.
B.
Inadequate planning and management of stormwater runoff
resulting from land development and redevelopment throughout a watershed
can also harm surface water resources by changing the natural hydrologic
patterns, accelerating stream flows (which increase scour and erosion
of streambeds and streambanks thereby elevating sedimentation), destroying
aquatic habitat and elevating aquatic pollutant concentrations and
loadings such as sediments, nutrients, heavy metals and pathogens.
Groundwater resources are also impacted through loss of recharge.
C.
A program of stormwater and watershed management,
including reasonable regulation of land development and redevelopment
causing loss of natural infiltration, is fundamental to the public
health, safety, welfare, and the protection of the people of the Township
and all the people of the Commonwealth, their resources, and the environment.
D.
Stormwater can be an important water resource by providing
groundwater recharge for water supplies and base flow of streams,
which also protects and maintains surface water quality.
E.
Public education on the control of pollution from
stormwater is an essential component in successfully addressing stormwater.
F.
Federal and state regulations require certain municipalities
to implement a program of stormwater controls. These municipalities
are required to obtain a permit for stormwater discharges from their
separate storm sewer systems under the National Pollutant Discharge
Elimination System (NPDES).
G.
Nonstormwater discharges to municipal storm sewer
systems can contribute to pollution of waters of the commonwealth.
H.
The use of green infrastructure and low-impact development (LID)
are intended to address the root cause of water quality impairment
by using systems and practices which use or mimic natural processes
to: 1) infiltrate and recharge, 2) evapotranspire, and/or 3) harvest
and use precipitation near where it falls to earth. Green infrastructure
practices and LID contribute to the restoration or maintenance of
predevelopment hydrology.
[Added 3-20-2023 by Ord.
No. 418]
[Amended 8-18-2014 by Ord. No. 377]
The purpose of this article is to promote health, safety, and
welfare within the Township and its watersheds by minimizing the harms
and maximizing the benefits through provisions designed to:
A.
Manage stormwater runoff impacts, including erosion and sedimentation,
at their sources and in community settings by regulating stormwater
collection and disposal activities, including incorporation of new
technologies using recognized best management practices (BMPs) where
practicable.
B.
Minimize increases in stormwater volume, peak flows and land development
impervious surfaces.
C.
Utilize and preserve the existing natural drainage systems as much
as possible.
D.
Manage stormwater impacts close to the runoff source while relying
on natural processes for treatment and infiltration on the development
site to the extent practicable.
E.
Provide for infiltration of stormwater, where geologically feasible,
in order to maintain groundwater recharge and prevent degradation
of surface water and groundwater quality and to otherwise protect
water resources.
F.
Maintain existing base flows and quality of streams and watercourses.
G.
Comply with legal water quality requirements under state law, including
regulations at 25 Pa. Code § 93.4a, to protect and maintain
existing uses and maintain a level of water quality to support those
uses in all streams, and to protect and maintain water quality in
special protection streams.
H.
Prevent scour and erosion of streambanks and streambeds, including
the preservation of the natural flood-carrying capacity of streams
and the improvement thereof where feasible.
I.
Provide for proper operations and maintenance of all permanent stormwater
management BMPs that are implemented in the Township.
J.
Provide a mechanism to identify controls necessary to meet the NPDES
permit requirements.
K.
Implement an illegal discharge detection and elimination program
to address nonstormwater discharges into the Township's storm sewer
system.
L.
Provide review procedures and performance standards for stormwater
management planning and BMP maintenance operations.
[Amended 3-20-2023 by Ord. No. 418]
The Township is empowered to regulate land use activities that
affect stormwater impacts by the authority of the Pennsylvania Municipalities
Planning Code, as amended,[1] and/or the Act of October 4, 1978, P.L. 864 (Act 167),
32 P.S. § 680.1 et seq., as amended, the Stormwater Management
Act.
[1]
Editor's Note: See 53 P.S. § 10101 et seq.
[Amended 8-18-2014 by Ord. No. 377]
A.
This article applies to any land development and/or regulated earth
disturbance activities within any watershed in the Township, and includes
regulation of the discharge of any stormwater runoff entering into
the Township's or private association storm sewer system or waterways
from lands within the boundaries of the Township.
B.
The following activities are defined as "regulated activities" and shall be regulated by this article unless exempted under § 122-79:
(1)
Land developments or redevelopment.
(2)
Construction of new buildings or additions to existing buildings.
(3)
Nonagricultural subdivision of land for the construction of building(s),
accessory structures, driveways, parking areas or other constructed
features that affect the natural hydrologic regime of the land.
(4)
Alteration of the natural hydrologic regime for any nonagricultural
or nonforestry purpose as may be not exempt from municipal control
by state law or regulation.
(5)
Construction or reconstruction of, or the addition of, new impervious
or semipervious surfaces (e.g., driveways, parking lots, roads, etc.,
except for reconstruction of municipal roads).
(6)
Diversion by piping or encroachments within or along any natural
or man-made channel.
(7)
Nonstructural and structural stormwater management BMPs or appurtenances
thereto.
(8)
Earth disturbance or installation of impervious surfaces of an area
of more then 5,000 square feet (or 1,000 square feet within the Neshaminy
Creek Watershed), whether singular or in combination on the same tract
or application.
(9)
Any of the above regulated activities which were approved more than
five years prior to the effective date of this article and resubmitted
for municipal approval.
(10)
Prohibited or polluted discharges to the surface of the land
or a stormwater collection or conveyance system as defined by law.
[Added 3-20-2023 by Ord.
No. 418]
Any other ordinance provision(s) or regulation of the municipality
inconsistent with any of the provisions of this article is hereby
repealed to the extent of the inconsistency only.
[Added 3-20-2023 by Ord.
No. 418]
In the event that a court of competent jurisdiction declares
any section or provision of this article invalid, such decision shall
not affect the validity of any of the remaining provisions of this
article.
[Added 3-20-2023 by Ord.
No. 418]
Any permit or authorization issued or approved based on false,
misleading or erroneous information provided by an applicant is void
without the necessity of any proceedings for revocation. Any work
undertaken or use established pursuant to such permit or other authorization
is unlawful. No action may be taken by a board, agency or employee
of the municipality purporting to validate such a violation.
[Added 3-20-2023 by Ord.
No. 418]
B.
Waivers or modifications of the requirements of this article may
be approved by the municipality if enforcement will exact undue hardship
because of peculiar conditions pertaining to the land in question,
provided that the modifications will not be contrary to the public
interest and that the purpose of this article is preserved. Cost or
financial burden shall not be considered a hardship. Modification
may be considered if an alternative standard or approach will provide
equal or better achievement of the purpose of the article. A request
for modifications shall be in writing and accompany the stormwater
management site plan submission. The request shall provide the facts
on which the request is based, the provision(s) of this article involved
and the proposed modification.
C.
No waiver or modification of any regulated stormwater activity involving
earth disturbance greater than or equal to one acre may be granted
by the municipality unless that action is approved in advance by the
Department of Environmental Protection (DEP) or the delegated County
Conservation District.
[Amended 8-18-2014 by Ord. No. 377]
A.
The following land use activities are exempt from the SWM plan submission
requirements of this article.
(1)
Use of land for gardening for home consumption.
(2)
Agriculture when operated in accordance with a conservation plan,
nutrient management plan or erosion and sedimentation control plan
approved by the County Conservation District, including activities
such as growing crops, rotating crops, tilling of soil and grazing
animals, and provided the activities are performed according to the
requirements of 25 Pa. Code Chapter 102. Installation of new or expansion
of existing farmsteads, animal housing, waste storage and production
areas having impervious surfaces that result in a net increase in
earth disturbance of greater than 5,000 square feet shall be subject
to the provisions of this article.
[Amended 3-20-2023 by Ord. No. 418]
(3)
Forest management and timber operations which are following the Department
of Environmental Protection's management practices contained in its
publication, "Soil Erosion and Sedimentation Control Guidelines for
Forestry," or other requirements that are outlined in 25 Pa. Code
Chapter 102, and are operating under an approved E&S plan, although
such operations must comply with stream buffer requirements.
[Amended 3-20-2023 by Ord. No. 418]
(4)
Any residential regulated earth disturbance activity that meets the
following exemption criteria is exempt from the water quantity (peak
rate), quality (groundwater recharge, volume), and plan requirements
of this chapter, subject to the approval of the Township Engineer.
This exemption does not relieve the applicant from implementing such
measures as are necessary to protect health, safety, and property.
[Amended 1-20-2020 by Ord. No. 409; 3-20-2023 by Ord. No. 418]
(a)
Exemption is cumulative such that once the exemption amount
is exceeded, all previously exempted impervious areas must be managed.
If prior to this article being adopted, the site received an exemption
from stormwater management, but the cumulative net increase in impervious
area since August 8, 2014, has exceeded 5,000 square feet, then the
project shall not be exempt again under the above criteria. Stormwater
management shall be installed to meet the requirements of this chapter.
(b)
Any area where existing impervious surface is removed shall
be scarified, overexcavated a minimum of 12 inches, restored with
amended or other approved soils and topped with at least six inches
of topsoil uniformly redistributed.
|
Stormwater Management Exemption Criteria
| |
|---|---|
|
Total Parcel Size
|
Net Increase in Impervious Area
|
|
0 to 25,000 square feet
|
1,000 square feet
|
|
>25,000 square feet to 1 acre
|
2,500 square feet
|
|
> 1 acre to 2 acres
|
4,000 square feet
|
|
> 2 acres
|
5,000 square feet
|
(5)
Road replacement or repairing.
(6)
Maintenance exemption. Any maintenance to an existing stormwater
management system made in accordance with plans and specifications
approved by the Township.
B.
This criterion shall apply to the total development or earth disturbance
even if the development is to take place in phases in which future
subdivisions and respective earth disturbance computations shall be
cumulatively considered.
C.
Additional exemption criteria and responsibilities of the property
owner, developer, contractor or agent:
(1)
An exemption shall not relieve the applicant from implementing such
measures as are necessary to protect the public health, safety, and
adjacent and downstream properties.
(2)
HQ and EV streams. This exemption shall not relieve the applicant
from meeting the special requirements for watersheds draining to high
quality (HQ) or exceptional value (EV) waters identified and source
water protection areas (SWPA) and requirements for nonstructural project
design sequencing in accordance with DEP regulations.
(3)
Drainage problems. If a drainage problem is documented or known to
exist downstream or downslope of the proposed activity Franconia Township
may deny exemption status to such activity and require compliance
in full with the requirements of this article.
D.
Emergency exemption. Emergency maintenance work performed for the
protection of public health, safety and welfare. A written description
of the scope and extent of any emergency work performed shall be submitted
to the Township within two calendar days of the commencement of the
activity. If the Township finds that the work is not an emergency,
then the work shall cease immediately and the requirements of this
ordinance shall be addressed as applicable.
E.
Exceptions specific to the Neshaminy Watershed.
(1)
Regulated activities that create impervious surfaces smaller than or equal to 1,000 square feet do not have to apply the volume control requirements of this article. Regulated activities of this size are exempt from the peak rate control requirements and the SWM site plan preparation located in § 122-82 of this article. If the activity is found to be a significant contributor of pollution to the waters of this commonwealth, the Township may enforce any of the above requirements of this article.
(2)
Regulated activities that create impervious surfaces greater than
1,000 square feet up to and including 5,000 square feet are exempt
only from the peak rate control requirements of this article.
(3)
Small project site plan for small residential regulated activities
creating impervious surface greater than 1,000 square feet up to and
including 5,000 square feet provides small residential regulated activities
with the opportunity to submit a plan without having to hire professional
services. Requires preapproval by Township Code Enforcement. Requirements
for the small project site plan as in the Township standard details.
F.
Additional exemption criteria.
(1)
Exemption responsibilities. An exemption shall not relieve the applicant
from implementing such measures as are necessary to protect public
health, safety, and property.
(2)
Drainage problems. Where drainage problems are documented or known
to exist downstream of or is expected from the proposed activity,
the Township may deny exemptions.
(3)
Exemptions are limited to specific portions of this article.
(4)
HQ and EV streams. The Township may deny exemptions in high quality
(HQ) or exceptional value (EV) waters and source water protection
areas (SWPA).
G.
The municipality
may deny or revoke any exemption pursuant to this section at any time
for any project that the municipality believes may pose a threat to
public health and safety or the environment.
[Added 3-20-2023 by Ord. No. 418]
A.
Approvals issued and actions taken under this article
do not relieve the applicant of the responsibility to secure required
permits or approvals for activities regulated by any other code, law,
regulation or ordinance. To the extent that this article imposes more
rigorous or stringent requirements for stormwater and watershed management,
the specific requirements contained in this article shall be followed.
B.
Earth disturbance activities and associated stormwater
management controls are also regulated under existing state law and
implementing regulations. Applicants under this article shall coordinate
between the Township and those parallel state agencies during the
application review process. Where different levels of protection or
use restriction between this article, other chapters of the Franconia
Code or state law exist, the greater protection or restriction shall
apply. Nothing in this article shall be construed to affect any of
the Township's Code requirements regarding stormwater or earth disturbance
regulatory matters which do not conflict with the provisions of this
article. Conflicting provisions in other chapters of the Franconia
Code shall be construed to retain the requirements of this article
addressing state water quality requirements.
[Amended 8-18-2014 by Ord. No. 377]
A.
All regulated earth disturbance activities within the Township shall
be designed, implemented, operated and maintained to meet the purposes
of this article through three elements:
(1)
Erosion and sediment control during the earth disturbance activities
(e.g., during construction).
(2)
Water quality protection measures with volume control after completion
of earth disturbance activities (PCSWM - post-construction stormwater
management, e.g., after construction), including an operations and
maintenance plan.
(3)
Water quantity management during and after earth disturbance or other
land development activities for peak rate runoff control.
B.
No regulated earth disturbance or stormwater discharge activities
within the Township shall commence until the Township issues written
approval of an SWM site plan which demonstrates compliance with the
requirements of this article and all applicable Township and state
permits issued.
[Amended 3-20-2023 by Ord. No. 418]
C.
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 § 122-83 of this article and to meet all requirements under Title 25 of the Pennsylvania Code and the Clean Streams Law.[1] Various BMPs and their design standards are listed in
the Erosion and Sediment Pollution Control Program Manual (E&S
Manual), No. 363-2134-008, as amended and updated.
[Amended 3-20-2023 by Ord. No. 418]
[1]
Editor's Note: See 35 P.S. § 691.1 et seq.
E.
The municipality may, after consultation with DEP, approve measures
for meeting the state water quality requirements other than those
in this article, provided that they meet the minimum requirements
of, and do not conflict with, state law, including, but not limited
to, the Clean Streams Law.[2] All best management practices (BMPs) used to meet the
requirements of this article shall conform to the state water quality
requirements and such more stringent requirements as may be determined
by the Township or DEP-approved Act 167 plans.
[Amended 3-20-2023 by Ord. No. 418]
[2]
Editor's Note: See 35 P.S. § 691.1 et seq.
F.
The design of all stormwater management facilities and best management
practice facilities shall comply with the requirements of this chapter
using PennDOT Region 5 intensity-duration-frequency curves (except
within the Neshaminy Watershed).
G.
Hot spots are areas where the land use or activity does, or has,
produce(d) a higher concentration of trace metals, hydrocarbons or
priority pollutants that may infest stormwater runoff as may be delineated
by qualified experts with supporting technical evaluations.
(1)
The use of infiltration BMPs is prohibited on hot spot land use areas.
Stormwater runoff from hot spot land uses shall be pretreated as approved
by DEP. In no case may the same BMP be employed consecutively to meet
this requirement.
(2)
Design of pretreatment shall include supporting documentation by
technical or scientific professionals with demonstrated expertise
in the field.
H.
All BMP design shall incorporate biologic controls consistent with
the West Nile guidance of the Montgomery County Conservation District
or similar recognized authority in management of the specific mosquito
carrier species.
I.
Impervious areas.
[Added 3-20-2023 by Ord.
No. 418]
(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 article.
(3)
For residential developments involving a subdivision and land development
creating a net increase of two or more new single-family dwelling
units, the stormwater management facilities shall be designed for
the proposed impervious area plus 25% of the proposed impervious area
per lot, without the future impervious area exceeding the maximum
permitted impervious area as permitted by the Township's Zoning
Ordinance.[3] If this requirement prevents the application from meeting
the stormwater exemption criteria, stormwater management shall be
required. The purpose is to have stormwater facilities installed with
new development to offset any potential impact to downstream neighbors.
(4)
For projects that add impervious area to a parcel, the total impervious area on the parcel is subject to the requirements of this article; except that the requirements in §§ 122-83 through 122-87 do not need to be retrofitted to existing impervious areas that are not being altered by the proposed regulated activity.
J.
Stormwater flows onto adjacent property shall not be created, increased,
decreased, relocated, or otherwise altered without written notification
to the adjacent property owner(s). Such stormwater flows shall be
subject to the requirements of this article.
[Added 3-20-2023 by Ord.
No. 418]
K.
The design of all facilities over karst shall include an evaluation
of measures to minimize adverse effects.
[Added 3-20-2023 by Ord.
No. 418]
L.
Infiltration BMPs should 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 article.
[Added 3-20-2023 by Ord.
No. 418]
M.
Normally dry, open-top storage facilities should 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, unless otherwise approved by the Township Engineer.
[Added 3-20-2023 by Ord.
No. 418]
N.
The design storm volumes to be used in the analysis of peak rates
of discharge should be obtained from the latest version of the Precipitation-Frequency
Atlas of the United States, National Oceanic and Atmospheric Administration
(NOAA), National Weather Service, Hydrometeorological Design Studies
Center, Silver Spring, Maryland. NOAA's Atlas 145 can be accessed
at: http://hdsc.nws.noaa.gov/hdsc/pfds/.
[Added 3-20-2023 by Ord.
No. 418]
O.
For all regulated activities, SWM BMPs shall be designed, implemented,
operated, and maintained to meet the purposes and requirements of
this article and to meet all requirements under Title 25 of the Pennsylvania
Code, the Clean Streams Law,[4] and the Storm Water Management Act.[5]
[Added 3-20-2023 by Ord.
No. 418]
P.
Various BMPs and their design standards are listed in the BMP Manual.
[Added 3-20-2023 by Ord.
No. 418]
[Amended 8-18-2014 by Ord. No. 377]
For any of the activities regulated by this article, the preliminary
or final approval of subdivision and/or land development plans, the
issuance of any building or occupancy permit, or the commencement
of any earth disturbance, such activity may not proceed until the
property owner or applicant or his/her agent has received written
approval of a stormwater and watershed management plan from the municipality
and an adequate erosion and sediment control plan review by the Conservation
District or NPDES permit for stormwater discharges associated with
construction activities (if the proposed land disturbance is greater
than one acre) or post-construction stormwater discharges.
A.
The following plan requirements apply to all land development and
certain regulated earth disturbance activities, and must be submitted
in support of any land development, nonexempt subdivision or grading
permit application for review and approval by the Township Engineer.
Issuance of drainage permits, either in conjunction or separately,
whether or not issued with any grading or building permits, must be
prior to commencement of regulated earth disturbance activities or
stormwater discharges.
(2)
Existing and resource and site analysis map (ERSAM) showing environmentally
sensitive areas, including, but not limited to, steep slopes, ponds,
lakes, streams, wetlands, hydric soils, vernal pools, stream buffers,
hydrologic soil groups. Existing and proposed land development, any
existing recharge areas, potential infiltration areas or permeable
soil areas, as well as off-site contributing runoff sources, downstream
receiving swales, channels or watercourses and affected downstream
or downslope properties shall also be included.
(3)
The overall stormwater and watershed management concept for the project,
including expected project schedule, development stages or project
phases and all interim facilities and management.
(4)
All structural and nonstructural stormwater collection, management
and disposal systems, including BMPs such as infiltration beds, bioretention,
areas for groundwater recharge, including wetland replacement areas,
swales, ponds for aesthetic considerations, and other modifications
to the land proposed or required in conformance with this article,
other chapters of the Franconia Code or state laws or regulations.
(5)
Erosion and sediment control plan, including all supporting computations,
as submitted and approved in conformance with state law and regulations
by the Montgomery County Conservation District under NPDES or adequacy
review as noted above.
(6)
Description, design and details for all non-point-source pollution
controls, including all BMPs during and after development.
(7)
Post-construction stormwater management (PCSWM) for both quality
and quantity controls.
(8)
Supporting hydrologic and hydraulic computations including source
and authority of computational techniques.
(9)
A post-construction operations and maintenance plan for all permanent
PCSWM facilities.
B.
Requirements applicable to all stormwater and watershed management
systems.
(1)
Stormwater drainage systems shall be provided such as to permit unimpeded
flow along natural watercourses, except as modified by stormwater
and watershed management facilities or open channels consistent with
this article.
(2)
The stormwater and watershed management plan must be designed consistent with the sequencing provisions of § 122-82C to ensure maintenance of the natural hydrologic regime and to promote groundwater recharge and protect groundwater and surface water quality and quantity. The SWM BMP plan designer must proceed sequentially in accordance with §§ 122-84, 122-85, and 122-86.
(3)
The existing points of concentrated drainage that discharge onto
adjacent property shall not be altered without permission of the affected
property owner(s) and shall be subject to any applicable discharge
criteria specified in this article.
(4)
Areas of existing diffused drainage discharge shall be subject to
any applicable discharge criteria in the general direction of existing
discharge, whether proposed to be concentrated or maintained as diffused
drainage areas, except as otherwise provided by this article. If diffused
flow is proposed to be concentrated and discharged onto adjacent property,
the applicant must document that adequate downstream conveyance facilities
exist to safely transport the concentrated discharge, or otherwise
prove that no erosion, sedimentation, flooding, or other harm will
result from the concentrated discharge.
(5)
Whenever a watercourse is located within a development site, it shall
remain open in its natural state and location and should not be piped,
impeded, or altered (except for road crossings). It is the responsibility
of the developer to stabilize existing eroded stream/channel bank.
(6)
Where a development site is traversed by watercourses drainage easements
shall be provided conforming to the line of such watercourses. The
terms of the easement shall prohibit excavation, the placing of fill
or structures, and any alterations that may adversely affect the flow
of stormwater within any portion of the easement.
(7)
When it can be shown that, due to topographic conditions, natural
drainageways on the site cannot adequately provide for drainage, open
channels may be constructed conforming substantially to the line and
grade of such natural drainageways. Work within natural drainageways
shall be subject to approval by the Township and the DEP through the
joint permit application process, or, where deemed appropriate by
DEP, through the general permit process.
(8)
Any stormwater and watershed management facilities regulated by this
article that would be located in or adjacent to waters of the commonwealth
or wetlands shall be subject to approval by DEP through the joint
permit application process, or, where deemed appropriate by DEP, through
the general permit process. When there is a question whether wetlands
may be involved, it is the responsibility of the applicant or their
agent to show that the land in question is not classified as wetlands
utilizing a recognized expert experienced in DEP and Corps of Engineers
criteria; otherwise, approval to work in the area must be obtained
from DEP.
(9)
Any stormwater and watershed management facilities regulated by this
article that would be located on, along or discharge into or beneath
the state highway rights-of-way shall be subject to approval by the
Pennsylvania Department of Transportation (PennDOT).
(10)
Minimization of impervious surfaces and infiltration of runoff
through seepage beds, infiltration trenches, etc., where feasible,
is required to reduce the size or need for facilities.
(11)
Roof drains shall discharge to infiltration areas or vegetative
BMPs to the maximum extent practicable.
(12)
Special requirements for watersheds draining to high quality
(HQ) and exceptional value (EV) waters. The temperature and quality
of water and streams that have been declared as exceptional value
and high quality are to be maintained as defined in Chapter 93, Water
Quality Standards, Title 25 of Pennsylvania Department of Environmental
Protection Rules and Regulations. Temperature-sensitive BMPs and stormwater
conveyance systems are to be used and designed with storage pool areas
and supply outflow channels and should be shaded with trees. This
will require modification of berms for permanent ponds and the relaxation
of restrictions on planting vegetation within the facilities, provided
that capacity for volumes and rate control is maintained. At a minimum,
the southern half on pond shorelines shall be planted with shade or
canopy trees within 10 feet of the pond shoreline. In conjunction
with this requirement, the maximum slope allowed on the berm area
to be planted is 10 to one. This will lessen the destabilization of
berm soils due to root growth. A long-term maintenance schedule and
management plan for the thermal control BMPs is to be established
and recorded for all development sites.
(13)
All stormwater runoff shall be pretreated for water quality
prior to discharge to surface or groundwater as required by Section
303 of this article.
C.
The applicant shall demonstrate that he or she designed the regulated
activities in the following sequence to minimize the increases in
stormwater runoff and impacts to water quality:
(1)
Prepare an existing resource and site analysis map (ERSAM), showing
environmentally sensitive areas including, but not limited to, steep
slopes, ponds, lakes, streams, wetlands, hydric soils, vernal pools,
floodplains, stream buffer zones, hydrologic soil groups A, B, C,
and D, any existing recharge areas and any other requirements outlined
in the Municipal Subdivision and Land Development Ordinance. Establish
stream buffer according to recommended criteria or applicable ordinances.
(2)
Prepare a draft project layout avoiding sensitive areas identified in § 122-82C(1) and minimizing total site earth disturbance as much as possible. The ratio of disturbed area to the entire site area and measures taken to minimize earth disturbance shall be included in the ERSAM.
(3)
Identify site specific existing conditions drainage areas, discharge
points, recharge areas, and hydrologic soil groups A and B.
(4)
Evaluate nonstructural stormwater and watershed management alternatives
as outlined in the Pennsylvania Handbook of Best Management Practices
for Developing Areas, DEP Pennsylvania Stormwater Best Management
Practices Manual or other applicable design manuals generally recognized
by the professional community.
(6)
Satisfy groundwater recharge (infiltration) objective (§ 122-85) and provide for stormwater treatment prior to infiltration.
(8)
Conduct a predevelopment runoff analysis.
(9)
Prepare final project design to maintain predevelopment drainage
areas and discharge points, to minimize earth disturbance and impervious
surfaces, and to reduce runoff to the maximum extent possible, the
use of surface or point discharges.
(10)
Conduct a post-construction conditions runoff analysis based
on the final design to meet the release rate and overbank flow limitations
and extreme event requirements
(11)
Manage any remaining runoff through treatment prior to discharge,
as part of detention, bioretention, direct discharge or other structural
control.
D.
The following permits, if applicable, must be obtained and provided
to the Township prior to issuance of a stormwater and watershed management
permit and commencement of regulated earth disturbance activities
or stormwater discharges.
(1)
Any Stormwater and Watershed Management facility that would be located
in or adjacent to surface waters of the Commonwealth, including wetlands,
subject to permit by DEP under 25 Pa. Code Chapter 105.
(2)
Any Stormwater and Watershed Management facility that would be located
on a State highway right-of-way, or require access from a state highway
subject to approval by the Pennsylvania Department of Transportation
(PENNDOT) under a Highway Occupancy Permit or adequacy review.
(3)
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 Pa. Code Chapter
105.
(4)
NPDES Permitting or adequacy review under DEP regulations that require
an Erosion and Sediment Control Plan for any Earth Disturbance activity
of 5,000 square feet or more, under 25 Pa. Code § 102.4(b).
[Amended 8-18-2014 by Ord. No. 377]
A.
No regulated earth disturbance activities within the Township shall
commence until approval by the Township of an erosion and sediment
control plan for construction activities and issuance of appropriate
outside agency permits and/or letters of adequacy.
B.
DEP has regulations that require an erosion and sediment control
plan for any earth disturbance activity of 5,000 square feet or more
under 25 Pa. Code § 102. The applicant agrees to meet these
regulations and requirements and shall provide evidence to the Township.
C.
In addition, under 25 Pa. Code Chapter 92, a DEP NPDES construction
activities permit is required for regulated earth disturbance activities.
D.
Evidence of any necessary permit(s) for regulated earth disturbance activities from the appropriate DEP regional office or County Conservation District must be provided to the Township. The issuance of an NPDES construction permit (or permit coverage under the statewide general permit) satisfies the requirements of § 122-26.
E.
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.
[Amended 8-18-2014 by Ord. No. 377; 3-20-2023 by Ord. No. 418]
A.
The green infrastructure and low-impact development practices provided in the BMP Manual shall be utilized for all regulated activities wherever possible. Water volume controls shall be implemented using the Design Storm Method in Subsection F or the Simplified Method in Subsection G below. For regulated activity areas equal or less than one acre that do not require hydrologic routing to design the stormwater facilities, this article 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. All regulated activities shall include such measures as necessary to:
(1)
Protect health, safety, and property.
(2)
Meet the water quality goals of this article by implementing measures
to:
(a)
Minimize disturbance to floodplains, wetlands, and wooded areas.
(b)
Create, maintain, or extend riparian buffers.
(c)
Avoid erosive flow conditions in natural flow pathways.
(d)
Minimize thermal impacts to waters of this commonwealth.
(e)
Disconnect impervious surfaces by directing runoff to pervious
areas, wherever possible, consistent with other provisions of this
Code.
(3)
Incorporate methods described in the Pennsylvania Stormwater Best
Management Practices Manual (BMP Manual). If methods other than green
infrastructure and LID methods are proposed to achieve the volume
and rate controls required under this article, the SWM site plan must
include a detailed justification demonstrating that the use of LID
and green infrastructure is not practicable.
B.
The BMPs must be designed, implemented and maintained to meet state
water quality requirements and any other more stringent requirements
as determined by the Township. (In the Neshaminy Watershed, post-development
total runoff should not be increased from predevelopment total runoff
for all storms equal to or less than the two-year twenty-four-hour
duration precipitation.)
C.
To control post-construction stormwater impacts from regulated earth
disturbance activities, state water quality requirements can be met
by BMPs, including site design, which provide for replication of pre-construction
stormwater infiltration and runoff conditions, so that post-construction
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,
as amended from time to time), this may be achieved by the following:
(1)
Infiltration: replication of pre-construction 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)
Streambank and streambed protection: management of volume and rate
of post-construction stormwater discharges to prevent physical degradation
of receiving waters (e.g., from scouring).
D.
DEP has regulations that require municipalities to ensure design,
implementation and maintenance of best management practices ("BMPs")
that control runoff from new development and redevelopment after regulated
earth disturbance activities are complete. These requirements include
the need to implement post-construction stormwater BMPs with assurance
of long-term operations and maintenance of those BMPs.
E.
Evidence of any necessary permit(s) for regulated earth disturbance
activities from the appropriate DEP regional office must be provided
to the Township.
F.
In addition to the performance standards and design criteria requirements
of this article, the applicant shall comply with the following water
quality requirements.
(1)
Adequate storage and treatment facilities will be provided to capture and treat stormwater runoff from developed or disturbed areas. The recharge volume computed under § 122-85A(2) may be a component of the water quality volume if the applicant chooses to manage both components in a single facility. If the recharge volume is less than the water quality volume, the remaining water quality volume may be captured and treated by methods other than recharge/infiltration BMPs. The required water quality volume (WQv) is the storage capacity needed to capture and to treat a portion of stormwater runoff from the developed areas of the site produced from 90% of the average annual rainfall (P).
(2)
To achieve this goal, the following criterion is established:
|
The following calculation formula is to be used to determine
the water quality storage volume (WQv) in acre-feet of storage. (Management
of sediment accumulation must be included with computations to insure
the maintenance of the desired storage volume.)
| |
|
Eqn. 122-84.1
| |
|
WQv = [(P)(Rv)(A)]/12
|
|
Where:
| ||||
|
WQv
|
=
|
Water Quality Volume (acre-feet)
| ||
|
P
|
=
|
Rainfall Amount equal to 90% of events producing this rainfall
(inches)
| ||
|
A
|
=
|
Area of the project contributing to the water quality BMP (acres)
| ||
|
Rv
|
=
|
0.05 + 0.009(I) where I is the percent of the area that is impervious
surface (impervious area/A* 100)
| ||
|
The P value to be utilized to meet this requirement is 1.95
(1.0 in Neshaminy Watershed) inches.
| ||||
(3)
Design of BMPs used for water quality control shall be in accordance
with design specifications outlined in the Pennsylvania Handbook of
Best Management Practices for Developing Areas, DEP BMP Design Manual,
or other professionally recognized applicable design manuals or peer
reviewed technical publications. The following factors shall be considered
when evaluating the suitability of BMPs used to control water quality
at a given development site:
(a)
Total contributing drainage area.
(b)
Permeability and infiltration rate of the site soils.
(c)
Slope and depth to bedrock.
(d)
Seasonal high water table.
(e)
Proximity to building foundations and well heads.
(f)
Erodibility of soils.
(g)
Land availability and configuration of the topography.
(h)
Peak discharge and required volume control.
(i)
Stream bank erosion.
(j)
Efficiency of the BMPs to mitigate potential water quality problems.
(k)
The volume of runoff that will be effectively treated.
(l)
The nature of the pollutant being removed.
(m)
Maintenance requirements.
(n)
Creation/protection of aquatic and wildlife habitat.
(o)
Recreational value.
(p)
Enhancement of aesthetic and property value.
G.
Simplified Method (regulated activities less than or equal to one
acre).
(1)
Stormwater facilities shall capture the runoff volume from at least
the first two inches of runoff from all new impervious surfaces.
|
Volume (cubic feet) = (two inches runoff/12 inches) * impervious
surface (square feet)
|
(2)
At least the first inch of runoff volume from the new impervious
surfaces shall be permanently removed from the runoff flow, i.e.,
it shall not be released into the surface waters of the commonwealth.
The calculated volume shall be either reused, evapotranspired or infiltrated
through structural or nonstructural means.
|
Volume (cubic feet) = (one inch runoff/12 inches) * impervious
surface (square feet)
|
(3)
Wherever possible, facilities should 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 should
be infiltrated.
[Amended 8-18-2014 by Ord. No. 377]
A.
Groundwater recharge (infiltration) BMPs shall meet the following minimum requirements: Regulated activities will be required to recharge (infiltrate) a portion of the runoff created by the development as part of an overall stormwater management plan designed for the site. The volume of runoff to be recharged shall be determined from § 122-85A(2)(a) or (b), depending upon demonstrated site conditions.
(1)
Infiltration BMPs intended to receive runoff from developed areas
shall be selected based on suitability of soils and site conditions
and shall be constructed on soils that have the following characteristics:
(a)
A minimum depth of 24 inches between the bottom of the BMP and
the limiting zone.
(b)
An infiltration and/or percolation rate sufficient to accept
the additional stormwater load and drain completely as determined
by field tests conducted by the applicant's design professional.
(c)
The recharge facility shall be capable of completely infiltrating
the recharge volume within four days (96 hours).
(d)
Pretreatment shall be provided prior to infiltration.
(e)
The requirements for recharge are applied to all disturbed areas,
even if they are ultimately to be an undeveloped land use such as
grass, since studies have found that compaction of the soils during
disturbance reduces their infiltrative capacity.
(2)
The recharge volume (Re) shall be computed by first obtaining the infiltration requirement using methods in either § 122-85A(2)(a) or (b), then multiplying by the total proposed impervious area. The overall required recharge volume for a site is computed by multiplying total impervious area by the infiltration requirement.
(a)
NRCS curve number equation. The following criteria shall apply:
|
The NRCS runoff shall be utilized to calculate infiltration
requirements (P) in inches.
| |
|
Equation 122-85.1
| |
|
For zero runoff: P = I (Infiltration) = (200/CN) - 2
|
|
Where:
| ||||
|
P
|
=
|
I = infiltration requirement (inches)
| ||
|
CN
|
=
|
SCS(NRCS) curve number of the existing conditions contributing
to the recharge facility.
| ||
|
This equation can be displayed graphically in and the infiltration
requirement can also be determined from Equation 122-85.1.
| |
|
Equation 122-85.2
| |
|
The recharge volume (Rev) required would
therefore be computed as:
| |
|
Rev = I * impervious area (SF)/12 = Cubic
Feet (CF)
|
|
Figure 122-85.1.
Infiltration Requirement Based upon NRCS Curve Number
Required Infiltration (I) in inches by NRCS CN
| |
|---|---|
 |
(b)
Annual recharge water budget approach. It has been determined that infiltrating 0.6 inch of runoff from the impervious areas will aid in maintaining the hydrologic regime of the watershed. If the goals of § 122-85A(2)(a) cannot be achieved, then 0.6 inch of rainfall shall be infiltrated from all impervious areas, up to an existing site conditions curve number of 77. Above a curve number of 77, Equation 122-85.1 or Figure 122-85.1 should be used to determine the infiltration requirement.
|
Where:
| ||||
|
I
|
=
|
0.6 inch
| ||
|
The recharge volume (Rev) required would
therefore be computed as:
| ||||
|
Rev
|
=
|
I * percent impervious area (SF)/12 = (CF)
| ||
|
The recharge values derived from these methods are the minimum
volumes the applicant must control through an infiltration/recharge
BMP facility. However, if a site has areas of soils where additional
volume of infiltration can be achieved, the applicant is encouraged
to recharge as much of the stormwater runoff from the site as possible.
| ||||
B.
The general process for designing the infiltration BMP shall be:
A detailed soils evaluation of the project site shall be required
to determine the suitability of recharge facilities. The evaluation
shall be performed by a qualified applicant and, at a minimum, address
soil permeability, depth to bedrock, and subgrade stability.
(1)
Analyze hydrologic soil groups as well as natural and man-made features
within the watershed to determine general areas of suitability for
infiltration practices.
(2)
Provide field tests, such as double ring infiltration tests, at the
level of the proposed infiltration surface to determine the appropriate
hydraulic conductivity rate.
(3)
Design the infiltration structure for the required storm volume based
on field determined capacity at the level of the proposed infiltration
surface.
(4)
Infiltration may not be feasible on every site due to site-specific
limitations such as soil type. Where the recharge volume requirement
cannot be physically accomplished, as may be supported by field soils
testing, supporting documentation and justification shall be supplied
to the municipality with the drainage plan. The design professional
shall have the burden of providing such testing and offering alternative
design to accomplish the goals of this article.
(5)
If on-lot infiltration structures are proposed by the applicant's
design professional, it must be demonstrated to the municipality that
the soils are conducive to infiltrate on the lots identified based
on field-determined capacity at the level of the proposed infiltration
surface and based on the safety factor of 50%. All open-air infiltration
facilities shall be designed to completely infiltrate runoff volume
within three days (72 hours) from the start of the design storm.
[Amended 3-20-2023 by Ord. No. 418]
C.
Extreme caution shall be exercised where infiltration is proposed
in geologically susceptible areas such as strip mines or limestone
areas. Extreme caution shall also be exercised where salt or chloride
would be a pollutant since soils do little to filter this pollutant
and it may contaminate the groundwater. Extreme caution shall be exercised
where infiltration is proposed in source water protection areas. The
qualified design professional shall evaluate the possibility of groundwater
contamination from the proposed infiltration/recharge facility and
perform a hydrogeologic justification study if necessary. The infiltration
requirement in high quality/exceptional value waters shall be subject
to the DEP's Title 25, Chapter 93, antidegradation regulations.[1] The municipality may require the installation of an impermeable
liner in BMP and/or detention basins where the possibility of groundwater
contamination exists. A detailed hydrogeologic investigation may be
required by the municipality.
[1]
Editor's Note: See 25 Pa. Code Chapter 93.
D.
The municipality shall require the applicant to provide safeguards
against groundwater contamination for uses which may cause groundwater
contamination, should there be a mishap or spill.
E.
Recharge/infiltration facilities shall be used in conjunction with
other innovative or traditional BMPs, stormwater control facilities,
and nonstructural stormwater management alternatives.
F.
Hot spots are sites where the land use or activity produces a higher
concentration of trace metals, hydrocarbons, or priority pollutants
often found in urban runoff. The use of infiltration BMPs within hot
spots is prohibited.
[1]
Editor's Note: Former § 122-86, Water quantity requirements
after land development and regulated earth disturbance activities
are complete for streambank protection, as amended, was repealed 3-20-2023 by Ord. No. 418.
[Amended 8-18-2014 by Ord. No. 377]
Land development and other regulated earth disturbance activities
must control proposed post-disturbance runoff rates to the existing
condition runoff rates for the applicable design storms and as otherwise
restricted herein.
A.
The East Branch Perkiomen Creek watershed has been divided into stormwater
management districts as shown on the Watershed Map in Appendix 1.[1] Proposed post-construction conditions peak rates of runoff from any regulated activity shall meet the peak release rates of runoff prior to development for the design storms specified below. These are in addition to the requirements for water quality (§ 122-84) and groundwater recharge (§ 122-85).
[Amended 3-20-2023 by Ord. No. 418]
|
District
|
Design Storm Proposed Conditions
|
Design Storm Existing Conditions
| |
|---|---|---|---|
|
A
|
2-year
|
1-year
| |
|
5-year
|
5-year
| ||
|
10-year
|
10-year
| ||
|
25-year
|
25-year
| ||
|
50-year
|
50-year
| ||
|
100-year
|
100-year
| ||
|
B
|
2-year
|
1-year
| |
|
5-year
|
2-year
| ||
|
10-year
|
5-year
| ||
|
25-year
|
10-year
| ||
|
50-year
|
25-year
| ||
|
100-year
|
50-year
| ||
|
C-1
|
2-year
|
1-year
| |
|
5-year
|
2-year
| ||
|
10-year
|
10-year
| ||
|
25-year
|
25-year
| ||
|
C-2
|
2-year
|
1-year
| |
|
5-year
|
2-year
| ||
|
10-year
|
5-year
| ||
|
25-year
|
10-year
| ||
|
50-year
|
25-year
| ||
|
100-year
|
50-year
|
[1]
Editor's Note: The Watershed Map is on file in the Township
office.
B.
All Neshaminy Watershed post-land development runoff rates shall meet the standards in Stormwater Management District A. All other stormwater and watershed management plans shall comply with the requirements of Stormwater Management District C-1, as noted in § 122-87A. Proposed conditions rates of runoff from any regulated activity shall not exceed the peak release rates of runoff from existing conditions for the design storms specified on the Stormwater Management District Watershed Map.
C.
District boundaries. The boundaries of the stormwater management
districts are shown on an official stormwater management districts
map that is available for inspection at the municipal office. The
exact location of the Stormwater Management District boundaries, as
they apply to a given development site, shall be determined by mapping
the boundaries using topographic contours to determine watershed ridgelines
(or most accurate data as may be required) provided as part of the
stormwater and watershed management plan.
D.
Sites located in more than one district. For a proposed development
site located within two or more stormwater management district category
subareas, the peak discharge rate from any subarea shall be the existing
conditions peak discharge for that subarea. The calculated peak discharges
shall apply regardless of whether the grading plan changes the drainage
area by subarea. An exception to the above may be granted if discharges
from multiple subareas recombine in proximity to the site. In this
case, peak discharge in any direction may be a one-hundred-percent
release rate, provided that the overall site discharge meets the weighted
average release rate.
E.
Off-site areas. Off-site areas that drain through a proposed development
site are not subject to release rate criteria when determining allowable
peak runoff rates to the extent they bypass the on-site controls.
However, on-site drainage facilities shall be designed to safely convey
off-site flows through the development site. Where off-site flows
are routed through the system their hydrological and hydraulic effects
on the total system must be considered.
F.
Site areas. Where the area of a site being impacted by a proposed
development activity differs significantly from the total site area,
only the proposed disturbed area utilizing stormwater management measures
shall be subject to the management district criteria. Nonimpacted
or undisturbed areas that do flow into or are bypassing the stormwater
management facilities would not be subject to the management district
criteria.
G.
Downstream hydraulic capacity analysis. Any downstream capacity hydraulic
analysis conducted in accordance with this article shall use the following
criteria for determining adequacy for accepting increased peak flow
rates:
(1)
Natural or man-made channels or swales must be able to convey the
increased runoff associated with a two-year return period event within
their banks at velocities consistent with protection of the channels
from erosion. Acceptable velocities shall be based upon criteria included
in the Department of Environmental Protection's Erosion and Sediment
Pollution Control Program Manual.
(2)
Natural or man-made channels or swales must be able to convey increased
twenty-five-year return period runoff without creating any hazard
to persons or property. In the event the natural or man-made channels
convey flows along or through developed properties, a one-hundred-year
return period runoff storm shall be utilized.
(3)
Culverts, bridges, storm sewers or any other facilities which must
pass or convey flows from the tributary area must be designed in accordance
with the Department of Environmental Protection's Chapter 105 regulations
(if applicable) and, at minimum, pass the increased twenty-five-year
return period runoff.
H.
Regional stormwater management facilities alternatives. For certain
areas within the study area, the Township may elect to provide one
control facility for more than one development site than to provide
an individual control facility for each development site. The initiative
and funding for any regional runoff control alternatives are the responsibility
of prospective applicants. The design of any regional control facility
must incorporate reasonable development of the entire upstream watershed.
The peak outflow of a regional control facility would be determined
on a case-by-case basis using the hydrologic model of the watershed
consistent with protection of the downstream watershed areas. "Hydrologic
model" refers to the calibrated model as developed for the stormwater
management plan. It is a requirement that, even if regional facilities
are proposed for the water quantity control, that the water quality,
streambank erosion, and recharge criteria be accomplished on site,
or as close to the source of the runoff as possible. All proposed
facilities must be consistent with the Township's NPDES MS4 permit
and TMDL strategy.
I.
Any stormwater management facility designed to store runoff and requiring
a berm or earthen embankment required or regulated by this article
shall be designed to provide an emergency spillway to handle flow
up to and including the 100-year proposed conditions. The height of
embankment must be set as to provide a minimum 1.0 foot of freeboard
above the maximum water surface elevation computed within the spillway
to the top of berm elevation for the 100-year proposed conditions
peak inflow. Should any stormwater management facility require a dam
safety permit under Title 25, Environmental Protection, Chapter 105,
Dam Safety and Waterway Management, the facility shall be designed
in accordance with Chapter 105 and meet the regulations of Chapter
105 concerning dam safety which may be required to pass storms larger
than a 100-year event.
[Amended 1-20-2020 by Ord. No. 409]
J.
Any facilities that constitute water obstructions (e.g., culverts,
bridges, outfalls, or stream enclosures), and any work involving wetlands
as directed in DEP Chapter 105 regulations (as amended or replaced
from time to time by DEP), shall be designed in accordance with Chapter
105 and will require a permit from DEP. Any other drainage conveyance
facility that does not fall under Chapter 105 regulations must be
able to convey, without damage to the drainage structure or roadway,
runoff from the twenty-five-year design storm with a minimum 1.0 foot
of freeboard measured below the lowest point along the top of the
roadway. Roadway crossings located within designated floodplain areas
must be able to convey runoff from a one-hundred-year design storm
with a minimum 1.0 foot of freeboard measured below the lowest point
along the top of the roadway. Any facility that constitutes a dam
as defined in DEP Chapter 105 regulations may require a permit under
dam safety regulations. Any facility located within a PennDOT right-of-way
must meet PennDOT minimum design standards and permit submission requirements.
K.
Any drainage/conveyance facility and/or channel that does not fall
under Chapter 105 regulations must be able to convey, without damage
to the drainage structure or roadway, runoff from the ten-year design
storm. Conveyance facilities to or exiting from stormwater management
facilities (i.e., detention basins) shall be designed to convey the
design flow to or from that structure. Roadway crossings located within
designated floodplain areas must be able to convey runoff from a one-hundred-year
design storm. Any facility located within a PennDOT right-of-way must
meet PennDOT minimum design standards and permit submission requirements.
L.
Additional criteria for Neshaminy Watershed stormwater calculation
methodology. The following criteria shall be used for runoff calculations:
(1)
For development sites not considered redevelopment, the ground cover
used to determine the existing conditions runoff volume and flow rate
shall be as follows:
(a)
Wooded sites shall use a ground cover of woods in good condition.
(b)
The undeveloped portion of the site, including agriculture,
bare earth, and fallow ground, shall be considered as "meadow in good
condition," unless the natural ground cover generates a lower curve
number (CN) or Rational "C" value (i.e., woods) as listed in SCS TR-55
and PennDOT Design Manual 5, respectively.
(2)
For development and redevelopment sites, the ground cover used to
determine the existing conditions runoff volume and flow rate for
the developed portion of the site shall be based upon actual land
cover conditions. If the developed site contains impervious surfaces,
20% of the impervious surface area shall be considered meadow in the
model for existing conditions.
M.
Alternative criteria for Neshaminy Watershed redevelopment sites.
For redevelopment sites, one of the following minimum design parameters
shall be accomplished, whichever is most appropriate for the given
site conditions as determined by the Township Engineer:
[Amended 8-18-2014 by Ord. No. 377]
A.
No regulated earth disturbance activities within the Township shall
commence until approval by the Township of a BMP operations and maintenance
plan which describes how the permanent (e.g., post-construction) stormwater
BMPs will be properly operated and maintained.
B.
The following items shall be included in the BMP operations and maintenance
plan:
(1)
Plat(s) of the project area, in a form that meets the requirements
for recording at the offices of the Recorder of Deeds of Montgomery
County, and shall be submitted on twenty-four-inch-by-thirty-six-inch
plan sheets. The contents of the plat(s) shall include, but not be
limited to:
(a)
Clear identification of the location and nature of permanent
stormwater BMPs;
(b)
The location of the project site relative to highways, municipal
boundaries or other identifiable landmarks;
(c)
Existing and final contours at intervals of two feet, or others,
as appropriate;
(d)
Existing streams, lakes, ponds, or other bodies of water within
the project site area;
(e)
Other physical features, including flood hazard boundaries,
sinkholes, streams, existing drainage courses, and areas of natural
vegetation to be preserved;
(f)
The locations of all existing and proposed utilities, sanitary
sewers, and waterlines within 50 feet of property lines of the project
site;
(g)
Proposed final changes to the land surface and vegetative cover,
including the type and amount of impervious area that would be added;
(h)
Proposed final structures, roads, paved areas, and buildings;
and
(i)
A thirty-foot-wide access easement around all stormwater BMPs
that would provide ingress to and egress from a public right-of-way.
(2)
A description of how each permanent stormwater BMP will be operated
and maintained, and the identity of the person(s) responsible for
operations and maintenance;
(3)
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
plan; and
(4)
A statement, signed by the landowner, acknowledging that the stormwater
BMPs are fixtures that can be altered or removed only after approval
by the Township.
A.
The drainage plan for the development site shall contain
an operation and maintenance plan prepared by the applicant and approved
by the Township Engineer. The operation and maintenance plan shall
outline required routine maintenance actions and schedules necessary
to ensure proper operation of the facility(ies). The municipality
shall make the final determination on the continuing maintenance responsibilities
prior to final approval of the SWM site plan. The municipality may
require a dedication of such facilities as part of the requirements
for approval of the SWM site plan. Such a requirement is not an indication
that the municipality will accept the facilities. The municipality
reserves the right to accept or reject the ownership and operating
responsibility for any portion of the stormwater management controls.
[Amended 3-20-2023 by Ord. No. 418]
B.
The drainage plan for the development site shall establish
responsibilities for the continuing operation and maintenance of all
proposed stormwater control facilities, consistent with the following
principles.
(1)
If a development consists of structures or lots which
are to be separately owned and in which streets, sewers and other
public improvements are to be dedicated to the municipality, stormwater
control facilities may also be dedicated to and maintained by the
municipality; however, the designated owner(s) of the facility(ies)
must be recorded on the final development plan.
(2)
In the instance of developments which include public
improvements that are to be dedicated to the municipality, stormwater
control facilities may be owned and maintained by an appropriately
established homeowners' association in lieu of municipal ownership/maintenance;
however, the designated owner(s) of the facility(ies) must be recorded
on the final development plan.
(3)
If a development site is to be maintained in a single
ownership or if sewers and other public improvements are to be privately
owned and maintained, then the ownership and maintenance of stormwater
control facilities may be the responsibility of the owner or private
management entity; however, the designated owner(s) of the facility(ies)
must be recorded on the final development plan,
C.
Facilities, areas, or structures used as SWM BMPs shall be enumerated
as permanent real estate appurtenances and recorded as deed restrictions
or conservation easements that run with the land.
[Added 3-20-2023 by Ord.
No. 418]
D.
The O&M plan shall be recorded as a restrictive deed covenant
that runs with the land.
[Added 3-20-2023 by Ord.
No. 418]
E.
The Township may take enforcement actions against an owner for any
failure to satisfy the provisions of this article.
[Added 3-20-2023 by Ord.
No. 418]
[Amended 3-20-2023 by Ord. No. 418]
A.
The Township shall review the BMP operations and maintenance plan
for consistency with the purposes and requirements of this article
and any permits issued by DEP.
B.
The Township shall notify the applicant in writing whether the BMP
operations and maintenance plan is approved or disapproved within
90 days, with reasons for any disapproval in writing. The Township
may also approve the plan with conditions and, if so, shall provide
the acceptable conditions for approval in writing.
C.
The applicant/developer will provide an as-built survey of all stormwater
BMPs within the Township's Survey Control System Datum and an
explanation of any discrepancies with the design and/or operations
and maintenance plan.
D.
The Township, upon recommendation of the Township Engineer, shall
make the final determination on the continuing maintenance responsibilities
prior to final approval of the drainage plan. The municipality reserves
the right to accept the ownership and operating responsibility for
any or all of the stormwater management controls.
E.
For any SWM site plan that proposes to use any BMPs other than green
infrastructure and LID practices to achieve the volume and rate controls
required under this article, the municipality will not approve the
SWM site plan unless it determines that green infrastructure and LID
practices are not practicable.
F.
A modification to a submitted SWM site plan that involves a change
in SWM BMPs or techniques, or that involves the relocation or redesign
of SWM BMPs, or that is necessary because soil or other conditions
are not as stated on the SWM site plan as determined by the municipality
shall require a resubmission of the modified SWM site plan in accordance
with this article.
G.
A disapproved SWM site plan may be resubmitted, with the revisions
addressing the municipality's concerns, to the municipality in
accordance with this article. The applicable review fee must accompany
a resubmission of a disapproved SWM site plan.
H.
The Township's approval of an SWM site plan authorizes the regulated activities contained in the SWM site plan for a maximum term of validity of five years following the date of approval. The Township may specify a term of validity shorter than five years in the approval for any specific SWM site plan. Terms of validity shall commence on the date the Township signs the approval for an SWM site plan. If an approved SWM site plan is not completed according to § 122-95 within the term of validity, then the Township may consider the SWM site plan disapproved and may revoke any and all permits.
[Amended 8-18-2014 by Ord. No. 377]
A.
It shall be unlawful to alter or remove any permanent stormwater
BMP required by an approved BMP operations and maintenance plan, or
to allow the property to remain in a condition which does not conform
to an approved BMP operations and maintenance plan, unless an exception
is granted, in writing, by the Township.
B.
Stormwater management (SWM) best management practices (BMPs) should
be inspected for proper operation by the landowner, or the owner's
designee (including the municipality for dedicated and owned facilities),
according to the following list of minimum frequencies and during
or immediately following precipitation events:
[Amended 3-20-2023 by Ord. No. 418]
(1)
Annually for the first five years;
(2)
Once every three years thereafter;
(3)
During or immediately after the cessation of a ten-year or greater
storm; and/or
(4)
As specified in the operations and maintenance (O&M) agreement.
Written reports should be filed with the Township in a designated
format suitable for Township compliance with NPDES MS4 permit reports
to document each inspection. The inspection report shall contain the
date and time of the inspection, the individual(s) who completed the
inspection, the location of the BMP, facility or structure inspected,
observations on performance, and recommendations for improving performance,
if applicable. Inspection reports shall be submitted to the municipality
within 30 days following completion of the inspection.
C.
Penalties.
(1)
Any person violating the provisions of this section shall be subject
to penalties that may range from liens against the property to fines
for each violation, recoverable with costs. Each day that the violation
continues shall constitute a separate offense and the applicable fines
are cumulative.
(2)
In addition, the municipality may institute injunctive, mandamus
or any other appropriate action or proceeding at law or in equity
for the enforcement of this section. Any court of competent jurisdiction
shall have the right to issue restraining orders, temporary or permanent
injunctions, mandamus, or other appropriate forms of remedy or relief.
A.
Prior to final approval of the site's stormwater management
plan, the applicant/developer shall sign and record an operations
and maintenance agreement or covenant as approved by the Township
Solicitor. This agreement will cover all stormwater BMPs that are
to be privately owned. Other items may be included in the agreement
where determined necessary to guarantee the satisfactory operation
and maintenance of all permanent stormwater BMPs. The agreement shall
be subject to the review and approval of the Township Solicitor.
B.
Whether dedication of stormwater management facilities,
including BMPs, is accepted by the Township Board of Supervisors or
remains with a private entity, the applicant/developer installing
such stormwater management facilities and BMPs shall be required to
contribute an amount to the Municipal Stormwater Maintenance Fund
to help defray costs of periodic inspections and maintenance expenses.
The amount of the deposit shall be determined as follows:
(1)
If the stormwater management facilities and best management
practices facility are to be privately owned and maintained, the deposit
shall cover the cost of periodic inspections performed by the municipality
for a period of 10 years, as estimated by the Municipal Engineer.
After that period of time, inspections will be performed at the expense
of the municipality.
(2)
If the stormwater management facilities and best management
practices facility are to be owned and maintained by the Township,
the deposit shall cover the estimated costs for maintenance and inspections
for 10 years and the total replacement of the facility. The Municipal
Engineer will establish the estimated costs utilizing information
submitted by the applicant as is allowed under this chapter.
(3)
The amount of the deposit to the fund shall be converted
to present worth of the annual series values. The Municipal Engineer
shall determine the present worth equivalents, which shall be subject
to the approval of the governing body.
C.
If a stormwater management facilities and/or best
management practices facility is proposed that also serves as a recreation
facility (e.g., ball field, lake), the municipality may reduce or
waive the amount of the maintenance fund deposit based upon the value
of the land for public recreation purpose.
A.
Stormwater and watershed management easements are
required for all areas used for off-site stormwater control, unless
a waiver is granted by the Township Board of Supervisors.
B.
Stormwater and watershed management easements shall be provided by the property owner if necessary for: 1) access for inspections and maintenance; or 2) preservation of stormwater runoff conveyance, infiltration, and detention areas and other BMPs, by persons other than the property owner. The purpose of the easement shall be specified in any agreement under § 122-92.
A.
The owner of any land upon which permanent BMPs will
be placed, constructed or implemented, as described in the BMP operations
and maintenance plan, shall record the following documents in the
Office of the Recorder of Deeds for Montgomery County within 15 days
of approval of the BMP operations plan by the Township:
B.
The Township may suspend or revoke any approvals granted
for the project site upon discovery of the failure of the owner to
comply with this section.
[Amended 8-18-2014 by Ord. No. 377; amended 3-20-2023 by Ord. No. 418]
A.
The municipality shall inspect all phases of the installation of
the best management practices (BMPs) and/or stormwater management
(SWM) facilities as deemed appropriate by the municipality, the Montgomery
County Conservation District and in conformance with DEP Chapter 102.
B.
During any stage of the work, if the municipality determines that
the BMPs and/or stormwater management facilities are not being installed
in accordance with the approved SWM site plan, the municipality may
revoke or suspend any existing permits or other approvals and issue
a cease-and-desist order until a revised SWM site plan is submitted
and approved, as specified in this article and until the deficiencies
are corrected.
C.
After receipt of the completion certification by the municipality,
a final inspection of all BMPs and/or stormwater management facilities
may be conducted by the municipality to confirm compliance with the
approved SWM site plan prior to the issuance of any occupancy permit.
D.
The applicant and/or developer shall be responsible for providing
as-built plans of all SWM BMPs included in the approved SWM site plan.
The as-built plans and an explanation of any discrepancies shall be
submitted to the Township for acknowledgment in conformance with the
Township NPDES MS4 permit recording requirements.
E.
The as-built submission shall include a certification of completion
signed by a qualified professional verifying that all SWM BMPs have
been constructed according to the approved plans and specifications.
The latitude and longitude coordinates for all permanent SWM BMPs
must also be submitted, at the central location of the BMPs. If any
qualified professionals contributed to the construction plans, they
must sign and seal the completion certificate.
F.
DEP or its designees (e.g., County Conservation Districts) ensure
compliance with any Chapter 102[1] permits issued, including those for stormwater and watershed
management. In addition to DEP compliance programs, the Township or
its designee may inspect all phases of the construction, operations,
maintenance and any other implementation of stormwater BMPs as required
by Franconia Township NPDES MS4 permits.
[1]
Editor's Note: See 25 Pa. Code Chapter 102.
A.
Upon presentation of proper credentials, duly authorized
representatives of the Township may enter at reasonable times upon
any property within the Township to inspect the implementation, condition,
or operation and maintenance of the stormwater BMPs in regard to any
aspect governed by this article.
B.
BMP owners and operators shall allow persons working
on behalf of the Township ready access to all parts of the premises
for the purposes of determining compliance with this article.
C.
Persons working on behalf of the Township shall have
the right to temporarily locate on any BMP in the Township such devices
as are necessary to conduct monitoring and/or sampling of the discharges
from such BMP.
D.
Unreasonable delays in allowing the Township access
to a BMP is a violation of this article.
[Amended 8-18-2014 by Ord. No. 377; 3-20-2023 by Ord. No. 418]
A.
The Township may charge a reasonable fee for review of stormwater
and watershed management site plans, stormwater management facilities,
BMP operations and maintenance plans, administrative/clerical processing,
attendance at meetings, inspections, etc., as may be allowed under
this article to defray review costs incurred by the Township. The
applicant shall pay all such fees.
B.
For SWM site plans that involve subdivision and land development,
the applicant shall provide a financial guarantee to the municipality
for the timely installation and proper construction of all stormwater
management controls as required by the approved SWM site plan and
this article in accordance with the provisions of Sections 509, 510,
and 511 of the Pennsylvania Municipalities Planning Code.[1]
[1]
Editor's Note: See, respectively, 53 P.S. §§ 10509,
10510, and 10511.
[Amended 8-18-2014 by Ord. No. 377]
The fees required by this article may cover:
A.
Administrative/clerical costs.
B.
The review of the stormwater and watershed management site plan,
stormwater management facilities, BMP operations and maintenance plan,
along with supporting documentation and reports by the Township Engineer.
C.
The site inspections, including, but not limited to, pre-construction
meetings, inspections during construction of stormwater BMPs, and
final inspection upon completion of the stormwater management Facilities,
stormwater BMPs and other required improvements and ancillary actions
as outlined on the stormwater and watershed management site plan,
including as-built survey plans thereof.
D.
Any additional work required to monitor and enforce any provisions
of this article, correct violations, and assure proper completion
of stipulated remedial actions.
E.
Review of post-construction stormwater management operation and maintenance
reports, including site inspections.
A.
No person in the Township shall allow, or cause to allow, stormwater discharges into the Township's separate storm sewer system which are not composed entirely of stormwater, except: 1) as provided in Subsection D below; and 2) discharges allowed under a state or federal permit.
B.
Discharges which may be allowed, based on a finding
by the Township that the discharges do not significantly contribute
to pollution to surface waters of the commonwealth, are:
[Amended 3-20-2023 by Ord. No. 418]
(1)
Discharges or flows from firefighting activities;
(2)
Uncontaminated pumped groundwater, water from foundation
or from footing drains or crawl space pumps;
(3)
Potable water sources, including dechlorinated waterlines
and fire hydrant flushings (if such discharges do not contain detectable
concentrations of total residual chlorine (TRC);
(4)
Diverted stream flows and springs;
(5)
Noncontaminated lawn watering, watering from lawn
maintenance, irrigation water, landscape drainage and flows from riparian
habitats and wetlands;
(6)
Noncontaminated HVAC condensation, and water from
geothermal systems; and
(7)
Water from individual residential (i.e., not commercial)
vehicle wash water where cleaning agents are not utilized.
C.
In the event that the Township determines that any of the discharges identified in Subsection B significantly contribute to pollution of waters of the commonwealth, or is so notified by DEP, the Township will notify the responsible person to cease the discharge.
D.
Upon notice provided by the Township under Subsection C, the discharger will have a reasonable time, as determined by the Township, to cease the discharge consistent with the degree of pollution caused by the discharge.
E.
Nothing in this section shall affect a discharger's
responsibilities under state law.
The following connections are prohibited, except as provided in § 122-99B above:
A.
Any drain or conveyance, whether on the surface or
subsurface, which allows any nonstormwater discharge, including sewage,
process wastewater and wash water, to enter the separate storm sewer
system, and any connections to the storm drain system from indoor
drains and sinks; and
B.
Any drain or conveyance connected from a commercial
or industrial land use to the separate storm sewer system which has
not been documented in plans, maps or equivalent records, and approved
by the Township.
A.
Roof drains shall not be connected to streets, sanitary
or storm sewers or roadside ditches, except as provided above (or
as part of a designed infiltration system overflow).
B.
When it is more advantageous to connect directly to
streets or storm sewers, connections of roof drains to streets or
roadside ditches may be permitted by the Township upon review by the
Township Engineer.
C.
Roof drains shall discharge to infiltration areas
or vegetative BMPs to the maximum extent practicable.
A.
No person shall modify, remove, fill, landscape or
alter any existing stormwater BMP, unless it is part of an approved
maintenance program, without the written approval of the Township.
B.
No person shall place any structure, fill, landscaping
or vegetation into a stormwater BMP or within a drainage easement
which would limit or alter the functioning of the BMP without the
written approval of the Township.
A.
Whenever the Township finds that a person has violated
a prohibition or failed to meet a requirement of this article, the
Township may order compliance by written notice to the responsible
person. Such notice may require, without limitation:
(1)
The performance of monitoring, analyses, and reporting;
(2)
The elimination of prohibited connections or discharges;
(3)
Cessation of any violating discharges, practices,
or operations;
(4)
The abatement or remediation of stormwater pollution
or contamination hazards and the restoration of any affected property;
(5)
Payment of a fine to cover administrative and remediation
costs;
(6)
The implementation of stormwater BMPs; and
(7)
Operation and maintenance of stormwater BMPs.
B.
Such notification shall set forth the nature of the
violation(s), and if a violation causes no immediate danger to life,
public health, or property, at its sole discretion, the Township may
establish a limited time limit for correction of said violation(s).
Said notice may further advise that, if applicable, should the violator
fail to take the required action within the established deadline,
the work will be done by the Township or designee, and the expense
thereof shall be charged to the violator.
[Amended 3-20-2023 by Ord. No. 418]
C.
Failure to comply within the time specified shall
also subject such person to the penalty provisions of this article.
All such penalties shall be deemed cumulative and shall not prevent
the Township from pursuing any and all other remedies available in
law or equity.
D.
It shall be unlawful for a person to undertake any regulated activity except as provided in an approved SWM site plan, unless specifically exempted in § 122-79.
[Added 3-20-2023 by Ord.
No. 418]
F.
Inspections regarding compliance with the SWM site plan are a responsibility
of the municipality.
[Added 3-20-2023 by Ord.
No. 418]
A.
Any building, land development, redevelopment, regulated
earthmoving activity or other permit or approval issued by the Township
may be suspended or revoked by the Township for:
(1)
Noncompliance with or failure to implement any provision
of the permit;
(2)
A violation of any provision of this article; or
(3)
The creation of any condition or the commission of
any act during construction or development which constitutes or creates
a hazard or nuisance, pollution or which endangers the life or property
of others.
B.
A suspended permit or approval shall be reinstated
by the Township when:
C.
A permit or approval which has been revoked by the
Township cannot be reinstated. The applicant may apply for a new permit
under the procedures outlined in this article.
[Amended 3-20-2023 by Ord. No. 418]
A.
Any person violating the provisions of this article
shall be guilty of a summary offense and, upon conviction, shall be
subject to a fine of not more than $600 for each violation, recoverable
with costs, or imprisonment of not more than 10 days, or both. Each
day that the violation continues shall be a separate offense, and
penalties shall be cumulative.
B.
In addition, the Township, through its Solicitor,
may institute injunctive, mandamus or any other appropriate action
or proceeding at law or in equity for the enforcement of this article.
Any court of competent jurisdiction shall have the right to issue
restraining orders, temporary or permanent injunctions, mandamus or
other appropriate forms of remedy or relief.
Any person aggrieved by any action of the Township
or its designee relevant to the provisions of this article may appeal
to the relevant judicial or administrative body according to law,
within the time period allowed.
