[HISTORY: Adopted by the Board of Commissioners
of the Township of Haverford as indicated in article histories. Amendments
noted where applicable.]
GENERAL REFERENCES
Environmental performance standards — See Ch. 76.
Floodplains — See Ch. 89.
Property maintenance — See Ch. 138.
Streets and sidewalks — See Ch. 157.
Subdivision and land development — See Ch. 160.
Zoning — See Ch. 182.
Attachment 1 - Table 105.1 Applicability
Attachment 2 - Appendix A Watershed MapAttachment 3 - Appendix BAttachment 4 - Appendix C-1 Drainage Plan ApplicationAttachment 5 - Appendix C-2 Drainage Plan ChecklistAttachment 6 - Appendix D Review Procedure Flowchart, Darby-Cobbs Creeks Watershed Stormwater MgmtAttachment 7 - Appendix E LID PracticesAttachment 8 - Appendix F Design CriteriaAttachment 9 - Appendix I Operations and Management Agreement
Attachment 2 - Appendix A Watershed MapAttachment 3 - Appendix BAttachment 4 - Appendix C-1 Drainage Plan ApplicationAttachment 5 - Appendix C-2 Drainage Plan ChecklistAttachment 6 - Appendix D Review Procedure Flowchart, Darby-Cobbs Creeks Watershed Stormwater MgmtAttachment 7 - Appendix E LID PracticesAttachment 8 - Appendix F Design CriteriaAttachment 9 - Appendix I Operations and Management Agreement
[Adopted 2-12-1973 by Ord. No. 1505]
This chapter shall be known and may be cited
as the "Township of Haverford Erosion and Sediment Control Ordinance."
The purpose of this chapter is to regulate the
modification of the natural terrain, the alteration of drainage, the
maintenance of artificial structures and surfaces and to provide for
certain erosion and sediment control measures within the Township
of Haverford so as to assure and safeguard health, safety, ecology
and general welfare in the Township of Haverford.
A.
It shall be unlawful for any person, firm or corporation
to pave, fill, strip, grade or regrade any land within the Township
of Haverford without first securing a permit as hereunder provided.
B.
It shall be unlawful for any person, firm or corporation
to disturb, modify, block, divert or affect the natural overland or
subsurface flow of stormwater within the Township of Haverford without
first securing a permit as hereunder provided.
C.
It shall be unlawful for any person, firm or corporation
to construct, erect or install any drainage dam, ditch, culvert, drainpipe,
bridge or any other structure or obstruction affecting the drainage
of any premises in the Township of Haverford without first securing
a permit as hereunder provided.
A.
Any person, firm or corporation proposing to engage
in an activity requiring a permit hereunder shall apply for a permit
by written application on a form furnished by the Township of Haverford.
B.
Proof of application for permit shall be submitted
to the Township of Haverford Planning Commission simultaneously with
preliminary plans to be considered for subdivision/development review.[1]
C.
The developer is encouraged to consult the general
development plans and detailed plans of any unit of government that
affect the tract to be developed and the area surrounding it before
he submits a preliminary plan for review. He should also become acquainted
with the Zoning Ordinance and other ordinances which regulate the
development of land in the Township of Haverford.[2]
D.
A separate application shall be required for each
grading permit. Three copies of the proposed plan, including specifications
and timing schedules, shall be submitted with each application for
a permit. One of the copies, at the discretion of the Director of
Code Enforcement, shall be submitted to the Delaware County Conservation
District for comment and review.
[Amended 6-30-1986 by Ord. No. 1960]
E.
Applications for review required under this chapter
shall be accompanied by a review fee as fixed by resolution of the
Board of Commissioners, which may be amended from time to time.
[Amended 2-8-1993 by Ord. No. 2168]
F.
All applications for a permit involving an area greater
than one acre shall be accompanied by a bond or escrow deposit, to
the benefit of the Township of Haverford in an amount as provided
by Township resolution. The form of the bond or escrow account shall
first be approved by the Township Solicitor, which shall guarantee
the full and complete compliance with this chapter.
[Amended 2-8-1993 by Ord. No. 2168]
The application for a permit shall be accompanied
by a plan of the property showing:
A.
A boundary line survey of the site on which the work
is to be performed.
B.
A description of the features, existing and proposed,
surrounding the site which are of importance to the proposed development.
C.
A description of the general topographic and soil
conditions, including drainage, on the site available through the
Delaware County Conservation District.
D.
The location and description of existing and future
manmade features of importance to the proposed development, i.e.,
cuts and fills, buildings, roads, etc.
E.
Plans and specifications of soil erosion and sediment
control measures in accordance with standards and specifications of
the Delaware County Conservation District or the Township of Haverford.
F.
A time schedule indicating the anticipated starting
and completion dates of the development sequence and the time of exposure
of each area prior to the completion of effective erosion and sediment
control measures.
[Amended 2-15-2005 by Ord. No. 2439]
A.
Stormwater management plans shall be as required in
this chapter.
(1)
The application for a permit shall be accompanied
by a plan of the property showing the location of all present and
proposed ditches, streams, pipes and other drainage structures and
proposed cuts and fills. In addition to showing present elevations
and dimensions and location and extent of all proposed grading and/or
drainage, the plan shall clearly indicate all buildings, parking areas
and driveways. Further, the plan shall indicate the present and proposed
sources, storage and disposition of water being channeled through
or across the premises, together with elevations, gradients and maximum
flow rates. The application shall describe the work to be performed,
the materials to be used and the manner or method of performance,
including provisions for protecting and maintaining existing drainage
facilities whether on public or private property. The applicant shall
supply data supporting the plan developed by a registered professional
civil engineer or an engineer qualified in hydrology.
(2)
Stormwater management plans shall be prepared in accordance
with this chapter.
B.
The following provisions apply to the carrying and
disposal of stormwater runoff:
(1)
The applicant shall agree to the granting and recording
of easements for drainage facilities, including acceptance of the
discharge of water on the property of others, provisions for maintenance
of slopes and swales and access for the maintenance of anti-erosion
facilities.
C.
If load-bearing fill is proposed, a soils investigation
report shall be submitted, which shall consist of test borings, laboratory
testings and engineering analysis to correlate surface and subsurface
conditions with the proposed grading plan. The results of the investigation
shall be presented in a report by a registered professional soils
engineer or geologist, which shall include data regarding the nature,
distribution and supporting ability of existing soils and rocks on
the site, conclusions and recommendations to ensure stable soil conditions
and groundwater control, as applicable. The Township of Haverford
may require such supplemental reports and data as it deems necessary.
Recommendations included in such reports and approved by the Township
of Haverford shall be incorporated in the plan or specifications.
(1)
Fills toeing out on natural slopes steeper than four
horizontal to one vertical shall not be made unless approved by the
Township of Haverford after receipt of a report, deemed acceptable
by the Township of Haverford Engineer, by a registered professional
soils engineer certifying that he has investigated the property, made
soil tests and that, in his opinion, such steeper slopes will safely
support the proposed fill.
(2)
Natural and/or existing slopes exceeding five horizontal
to one vertical shall be benched or continuously stepped into competent
materials prior to placing all classes of fill.
[Amended 6-30-1986 by Ord. No. 1960]
Upon the submission of an application which
conforms to the provisions of this chapter, the Director of Code Enforcement,
after consultation with the Township of Haverford Engineer, shall
issue the necessary permit.
A.
Notwithstanding any provision of this chapter or any
condition of the permit, the permittee is responsible for the prevention
of damage to other property or personal injury which may be affected
by the activity requiring a permit.
B.
No person, firm or corporation shall modify, fill,
excavate, pave, grade or regrade land in any manner so close to a
property line as to endanger or damage any adjoining street, sidewalk,
alley or any other public or private property without supporting and
protecting such property from settling, cracking, erosion, sediment
or other physical damage or personal injury which might result.
C.
No person, firm or corporation shall deposit or place
any debris or any other material whatsoever or to cause such to be
thrown or placed in any drainage ditch or drainage structure in such
a manner as to obstruct free flow.
D.
No person, firm or corporation shall fail to adequately
maintain in good operating order any drainage facility on his premises.
All drainage ditches, culverts, drainpipes and drainage structures
shall be kept open and free-flowing at all times.
E.
The owner of any property on which any work has been
done pursuant to a permit granted under this chapter shall continuously
maintain and repair all graded surfaces and antierosion devices, retaining
walls, drainage structures or means and other protective devices,
plantings and ground cover installed or completed.
F.
All graded surfaces shall be seeded, sodded and/or
planted or otherwise protected from erosion within 60 days and shall
be watered, tended and/or maintained until growth, in the case of
vegetation, is well established. The disturbed area and duration of
exposure shall be kept to a practical minimum.
G.
All trees in the area of extreme grade change shall
be removed unless protected with suitable tree wells. However, extreme
precautions shall be taken to prevent the unnecessary removal of trees.
H.
When required, adequate provisions shall be made for
dust control measures as are deemed acceptable by the Township of
Haverford.
I.
All plans and specifications accompanying applications
for permits shall include provisions for both interim (temporary)
and ultimate (permanent) erosion and sediment control.
(1)
The design, installation and maintenance of erosion
and sediment control measures shall be accomplished in accordance
with standards and specifications established by the Delaware County
Conservation District as adapted from standards and specifications
of the Soil Conservation Service, United States Department of Agriculture.
(2)
Technical standards for the design and installation
of erosion and sediment control measures are on file with the Township
of Haverford office, the office of the Delaware,County Conservation
District and other governmental agency offices.
(3)
Standards and specifications adopted for the purposes
of this chapter and by the Delaware County Conservation District include
but are not limited to the following basic conservation measures:
(a)
Temporary cover on critical areas.
(b)
Permanent grass and legume cover on critical
areas on prepared seedbed.
(c)
Permanent grass and legume cover on critical
areas on unprepared seedbed.
(d)
Sodding.
(e)
Mulching.
(f)
Temporary diversion.
(g)
Permanent diversion.
(h)
Grassed waterway or outlet.
(i)
Grade stabilization structure.
(j)
Debris basin.
(k)
Drain.
(l)
Drainage, main or lateral.
J.
A quality control program is critical for fills, therefore,
whenever fill material is to be used, each layer of compacted fill
should be tested to determine its dry density as per ASTM D 1556.
The density of each layer should not be less than 95% of maximum dry
density as determined by ASTM D 1557.
A.
All inspections shall be the responsibility of the
Director of Code Enforcement or his qualified designee.
[Amended 6-30-1986 by Ord. No. 1960]
B.
Inspections will be carried out on a random basis, except as stated in Subsection E of this section. However, a set of as-built plans shall be on file at the site and authenticated by a registered professional engineer. When it is deemed acceptable to the Director of Code Enforcement, a designated qualified person may authenticate the as-built plans and will assume full responsibility for quality of work.
[Amended 6-30-1986 by Ord. No. 1960]
C.
Any and all as-built plans shall be available on the
site at all times and be subject to inspection and inquiry.
D.
Engineering check notes shall accompany all as-built
plans which involve structural or mechanical measures and shall serve
as supporting evidence that structures meet design standards and specifications.
E.
A final inspection shall be conducted by the Director
of Code Enforcement to certify compliance with this chapter. Satisfactory
compliance with this chapter shall be necessary before issuance of
an occupancy permit.
[Amended 6-30-1986 by Ord. No. 1960]
[Amended 6-30-1986 by Ord. No. 1960]
All applicants shall bear all cost of inspections
required hereunder and shall deposit with the Director of Finance
such sum as the Director of Code Enforcement shall determine to be
necessary to guarantee payment of the cost of such inspections.
[Amended 6-13-1988 by Ord. No. 2019; 3-12-2012 by Ord. No.
2660]
Any person, firm or corporation violating any
provision of this chapter shall, upon summary conviction before any
District Justice of the Peace, pay a fine not exceeding $1,000 and
costs of prosecution; and in default of one payment of the fine and
costs, the violator may be sentenced to the county jail for a term
of not more than 90 days. Each and every day in which any person,
firm or corporation shall be in violation of this chapter shall constitute
a separate offense.
[Adopted 2-15-2005 by Ord. No. 2439]
This article shall be known as the Township
of Haverford Stormwater Management Code.
The Board of Commissioners of Haverford Township
finds that:
A.
Inadequate management of accelerated stormwater runoff
resulting from development throughout a watershed increases flood
flows and velocities, contributes to erosion and sedimentation, overtaxes
the carrying capacity of existing streams and storm sewers, greatly
increases the cost of public facilities to convey and manage stormwater,
undermines floodplain management and flood reduction efforts in upstream
and downstream communities, reduces groundwater recharge, and threatens
public health and safety.
B.
Inadequate planning and management of stormwater runoff
resulting from land development 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 comprehensive program of stormwater management,
including minimization of impacts of development, redevelopment, and
activities causing accelerated erosion and loss of natural infiltration,
is fundamental to the public health, safety, welfare, and the protection
of the people of Haverford Township and all of 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 baseflow of streams, which
also protects and maintains surface water quality.
E.
Impacts from stormwater runoff can be minimized by
using project designs that maintain the natural hydrologic regime
and sustain high water quality, groundwater recharge, stream baseflow,
and aquatic ecosystems. The most cost-effective and environmentally
advantageous way to manage stormwater runoff is through nonstructural
project design that minimizes impervious surfaces and sprawl, avoids
sensitive areas (i.e., stream buffers, floodplains, steep slopes),
and considers topography and soils to maintain the natural hydrologic
regime.
F.
Public education on the control of pollution from
stormwater is an essential component in successfully addressing stormwater.
G.
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).
H.
Nonstormwater discharges to municipal separate storm
sewer systems can contribute to pollution of waters of the commonwealth
by Haverford Township.
The purpose of this article is to promote the public health, safety, and welfare within the Township of Haverford by maintaining the natural hydrologic regime and minimizing the impacts described in § 78-14 of this article through provisions designed to:
A.
Promote alternative project designs and layouts that
minimize the impacts on surface and groundwater.
B.
Promote nonstructural best management practices (BMPs).
C.
Minimize increases in runoff stormwater volume.
D.
Minimize impervious surfaces.
E.
Manage accelerated stormwater runoff and erosion and
sedimentation problems and stormwater runoff impacts at their source
by regulating activities that cause these problems.
F.
Provide review procedures and performance standards
for stormwater planning and management.
G.
Utilize and preserve existing natural drainage systems
as much as possible.
H.
Manage stormwater impacts close to the runoff source,
requiring a minimum of structures and relying on natural processes.
I.
Focus on infiltration of stormwater to maintain groundwater
recharge, to prevent degradation of surface and groundwater quality,
and to otherwise protect water resources.
J.
Maintain existing baseflows and quality of streams
and watercourses, where possible.
K.
Meet legal water quality requirements under state
law, including regulations at 25 Pennsylvania Code Chapter 93.4a requiring
protection and maintenance of "existing uses" and maintenance of the
level of water quality to support those uses in all streams, and the
protection and maintenance of water quality in "special protection"
streams.
L.
Address the quality and quantity of stormwater discharges
from the development site.
M.
Provide a mechanism to identify stormwater controls
necessary to meet NPDES permit requirements.
N.
Implement an illegal discharge detection and elimination
program that addresses nonstormwater discharges into Haverford Township's
separate storm sewer system.
O.
Preserve the flood-carrying capacity of streams.
P.
Prevent scour and erosion of streambanks and streambeds.
Q.
Provide performance standards and design criteria
for watershed-wide stormwater management and planning.
R.
Provide proper operation and maintenance of all permanent
stormwater management facilities and BMPs that are implemented in
the Township.
The Township is empowered to regulate land use
activities that affect runoff and surface and groundwater quality
and quantity by the authority of:
A.
Act of October 4, 1978, 32 P.S., P.L. 864 (Act 167)
§ 680.1 et seq., as amended, the "Stormwater Management
Act" (hereinafter referred to as "the Act");
B.
Water Resources Management Act of 2002, as amended;
C.
Second Class Township Code, 53 P.S. §§ 66501
et seq., 66601 et seq., and the Borough Code, 53 P.S. § 46201
et seq.;
D.
Pennsylvania Municipalities Planning Code, Act 247,
as amended.
A.
This article shall apply to all areas of Haverford
Township.
B.
This article shall only apply to permanent structural
and nonstructural stormwater management BMPs constructed as part of
any of the regulated activities listed in this section.
C.
This article contains only the stormwater management
performance standards and design criteria that are necessary or desirable
from a watershed-wide perspective. Local stormwater management design
criteria (e.g., inlet spacing, inlet type, collection system design
and details, outlet structure design, etc.) shall continue to be regulated
by the applicable municipal ordinances and applicable state regulations.
D.
The following activities are defined as "regulated activities" and shall be regulated by this article unless exempted by § 78-18:
(1)
Land development.
(2)
Subdivisions.
(3)
Alteration of the natural hydrologic regime.
(4)
Construction or reconstruction of or addition of new
impervious or semipervious surfaces (i.e., driveways, parking lots,
roads, etc.).
(5)
Construction of new buildings or additions to existing
buildings.
(6)
Redevelopment.
(7)
Diversion piping or encroachments in any natural or
man-made channel.
(8)
Nonstructural and structural stormwater management
BMPs or appurtenances thereto.
(9)
Earth disturbance activities of greater than 5,000
square feet.[1]
[1]
Editor's Note: This article applies to any earth disturbance activity greater than or equal to 5,000 square feet that is associated with a development or redevelopment project. Earth disturbance activities of less than one acre that are associated with redevelopment projects are exempt from the § 78-36 streambank erosion requirements. Earth disturbance activities and associated stormwater management controls are also regulated under existing state law and implementing regulations. This article shall operate in coordination with those parallel requirements; the requirements of this article shall be no less restrictive in meeting the purposes of this article than state law.
(10)
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.
|
Table 105.1[2] summarizes the applicability requirements of the ordinance.
"Proposed impervious surface" in Table 105.1 includes new, additional,
or replacement impervious surface/cover. Repaving existing surfaces
without reconstruction does not constitute "replacement."
|
[2]
Editor's Note: Table 105.1, Applicability, is included at the end of this chapter.
A.
Exemptions for land use activities. The following
land use activities are exempt from the drainage 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. 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.
(3)
Forest management operations which are following the Department of Environmental Protection's (DEP) management practices contained in its publication "Soil Erosion and Sedimentation Control Guidelines for Forestry" and are operating under an approved erosion and sedimentation plan and must comply with the stream buffer requirements in § 78-35G.
(4)
Road replacement, development, or redevelopment that
has less than 1,000 square feet of new, additional, or replaced impervious
surface/cover, or in the case of earth disturbance only, less than
5,000 square feet of disturbance, is exempt from this article.
B.
Exemptions for land development activities.
(2)
These criteria shall apply to the total development
even if the development is to take place in phases. The date of the
municipal ordinance adoption shall be the starting point from which
to consider tracts as "parent tracts" upon which future subdivisions
and respective earth disturbance computations shall be cumulatively
considered.
|
The activities exempted above are still encouraged
to implement the stormwater management practices as indicated in Appendix
B.[1]
|
[1]
Editor's Note: Appendix B is included at the end of this chapter.
(3)
The developer should first determine if the proposed
activity will result in the introduction of 1,000 square feet or more
of new, additional, or replacement impervious surface. If not, the
developer should next determine if the proposed activity will involve
earthmoving of over 5,000 square feet. If not, then the project is
exempt from the drainage plan requirements. Examples:
(a)
A project introducing 1,100 square feet of impervious
cover, but only 4,900 square feet of earthmoving is regulated by this
article.
(b)
A project involving 5,100 square feet of earthmoving,
but resulting in 900 square feet of impervious cover is regulated.
(c)
A project introducing 900 square feet of impervious
cover and involving 4,900 square feet of earthmoving is exempt from
the drainage plan requirements of this article.
C.
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)
HQ and EV streams. An exemption shall not relieve the applicant from meeting the special requirements for watersheds draining to identified high quality (HQ) or exceptional value (EV) waters and source water protection areas (SWPA) and requirements for nonstructural project design sequencing (§ 78-33).
(3)
Drainage problems. If a drainage problem is documented
or known to exist downstream of or is expected from the proposed activity,
then Haverford Township may require the applicant to comply with this
article.
(4)
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 of Haverford within two calendar
days of the commencement of the activity. If the Township of Haverford
finds that the work is not an emergency, then the work shall cease
immediately, and the requirements of this article shall be addressed
as applicable.
(5)
Maintenance exemption. Any maintenance to an existing
stormwater management system made in accordance with plans and specifications
approved by the municipal Engineer or the Township of Haverford.
(6)
Even though the developer is exempt, he/she is not
relieved from complying with other regulations.
Any ordinance or ordinance provision of Haverford
Township inconsistent with any of the provisions of this article is
hereby repealed to the extent of the inconsistency only.
Should any section or provision of this article
be declared invalid by a court of competent jurisdiction, such decision
shall not affect the validity of any of the remaining provisions of
this article.
A.
Approvals issued pursuant to this article do not relieve
the applicant of the responsibility to secure required permits or
approvals for activities regulated by any other applicable code, rule,
act, or ordinance.
B.
To the extent that this article imposes more rigorous
or stringent requirements for stormwater management, the specific
requirements contained in this article shall be followed.
C.
Nothing in this article shall be construed to affect
any of Haverford Township's requirements regarding stormwater matters
that do not conflict with the provisions of this article, such as
local stormwater management design criteria (e.g., inlet spacing,
inlet type, collection system design and details, outlet structure
design, etc.). Conflicting provisions in other municipal ordinances
or regulations shall be construed to retain the requirements of this
article addressing state water quality requirements.
For the purposes of this article, certain terms
and words used herein shall be interpreted as follows:
A.
Words used in the present tense include the future
tense; the singular number includes the plural, and the plural number
includes the singular; words of masculine gender include feminine
gender; and words of feminine gender include masculine gender.
B.
The word "includes" or "including" shall not limit
the term to the specific example, but is intended to extend its meaning
to all other instances of like kind and character.
C.
The word "person" includes an individual, firm, association,
organization, partnership, trust, company, corporation, unit of government,
or any other similar entity.
D.
The words "shall" and "must" are mandatory; the words
"may" and "should" are permissive.
E.
The words "used" or "occupied" include the words "intended,
designed, maintained, or arranged to be used, occupied, or maintained."
As used in this article, the following terms
shall have the meanings indicated:
The removal of the surface of the land through the combined
action of man's activity and the natural processes at a rate greater
than would occur because of the natural process alone.
The work of producing crops and raising livestock, including
tillage, plowing, disking, harrowing, pasturing, mushroom growing,
nursery, and sod operations and installation of conservation measures.
Construction of new buildings or impervious area is not considered
an agricultural activity.
As applied to land, a change in topography as a result of
the moving of soil and rock from one location or position to another;
also the changing of surface conditions by causing the surface to
be more or less impervious; land disturbance.
A person who has filed an application for approval to engage in any regulated activity defined in § 78-17 of this article.
Engineering or site drawings maintained by the contractor
as he constructs the project and upon which he documents the actual
locations of the building components and changes to the original contract
documents. These documents, or a copy of same, are turned over to
the municipal Engineer at the completion of the project.
The channel at the top-of-bank or point from where water
begins to overflow onto a floodplain.
Portion of stream discharge derived from groundwater; the
sustained discharge that does not result from direct runoff or from
water diversions, reservoir releases, piped discharges, or other human
activities.
A stormwater retention area that utilizes woody and herbaceous
plants and soils to remove pollutants before infiltration occurs.
Methods, measures, or practices used to prevent or reduce
surface runoff and/or water pollution, including but not limited to
structural and nonstructural stormwater management practices and operation
and maintenance procedures. See also "nonstructural best management
practices (BMPs)."
The area of land immediately adjacent to any stream, measured
perpendicular to and horizontally from the top-of-bank on both sides
of a stream (see "top-of-bank").
An open drainage feature through which stormwater flows.
Channels include, but shall not be limited to, natural and man-made
drainageways, swales, streams, ditches, canals, and pipes flowing
partly full.
The widening, deepening, or headward cutting of channels
and waterways caused by stormwater runoff or bankfull flows.
An underground reservoir or tank for storing rainwater.
The Delaware County Conservation District.
A facility or structure used for the transportation or transmission
of something from one place to another.
A structure with its appurtenant works which carries water
under or through an embankment or fill.
A man-made barrier, together with its appurtenant works,
constructed for the purpose of impounding or storing water or another
fluid or semifluid. A dam may include a refuse bank, fill, or structure
for highway, railroad, or other purposes which impounds or may impound
water or another fluid or semifluid.
The Pennsylvania Department of Environmental Protection.
The agent of the Delaware County Planning Commission, Delaware
County Conservation District, and/or agent of the governing body involved
with the administration, review, or enforcement of any provisions
of this article by contract or memorandum of understanding.
A Pennsylvania-registered professional engineer, registered
landscape architect, or registered professional land surveyor trained
to develop stormwater management plans.
The magnitude and temporal distribution of precipitation
from a storm event measured in probability of occurrence (e.g., a
five-year storm) and duration (e.g., 24 hours), used in the design
and evaluation of stormwater management systems.
An impoundment designed to collect and retard stormwater
runoff by temporarily storing the runoff and releasing it at a predetermined
rate. Detention basins are designed to drain completely soon after
a rainfall event and become dry until the next rainfall event.
A person who seeks to undertake any regulated earth disturbance
activities at a project site in Haverford Township.
Any human-induced change to improved or unimproved real estate,
whether public or private, including but not limited to land development,
construction, installation, or expansion of a building or other structure,
land division, street construction, drilling, and site alteration,
such as embankments, dredging, grubbing, grading, paving, parking
or storage facilities, excavation, filling, stockpiling, or clearing.
As used in this article, development encompasses both new development
and redevelopment.
The specific tract or parcel of land where any regulated activity set forth in § 78-15 is planned, conducted, or maintained.
The outside bark diameter at breast height which is defined
as 4.5 feet (1.37m) above the forest floor on the uphill side of the
tree.
Drainage discharge that is not confined to a single point
location or channel, including sheet flow or shallow concentrated
flow.
The point of discharge for a stormwater facility.
Unstabilized land area where an earth disturbance activity
is occurring or has occurred.
A man-made waterway constructed for irrigation or stormwater
conveyance purposes.
That portion of the property line of the lot, tract, or parcels
of land being developed, located such that overland or pipe flow from
the project site would be directed towards it by gravity.
A stormwater management facility designed to transport stormwater
runoff that includes channels, swales, pipes, conduits, culverts,
and storm sewers.
A right granted by a landowner to a grantee allowing the
use of private land for stormwater management purposes.
A permit issued by Haverford Township after the drainage
plan has been approved.
The documentation of the stormwater management system, if any, to be used for a given development site, the contents of which are established in § 78-25.
A construction or other human activity which disturbs the
surface of land, including but not limited to clearing and grubbing,
grading, excavations, embankments, land development, agricultural
plowing or tilling, timber harvesting activities, road maintenance
activities, mineral extraction, and the moving, depositing, stockpiling,
or storing of soil, rock, or earth materials.
A conveyance area that is used to pass peak discharge greater
than the maximum design storm controlled by the stormwater facility.
A structure or activity that changes, expands or diminishes
the course, current, or cross-section of a watercourse, floodway or
body of water.
The process by which the surface of the land, including water/stream
channels, is worn away by water, wind or chemical action.
A plan that is designed to minimize accelerated erosion and
sedimentation. Said plan must be submitted to and approved by the
appropriate conservation district before construction can begin.
Surface waters of high quality which satisfy Pennsylvania
Code Title 25 Environmental Protection, Chapter 93, Water Quality
Standards, § 93.4b(b) (relating to anti-degradation).
The initial condition of a project site prior to the proposed
alteration. If the initial condition of the site is undeveloped land,
the land use shall be considered as "meadow" unless the natural land
cover is proven to generate a lower curve number or Rational "c" value,
such as forested lands.
A temporary condition of partial or complete inundation of
land areas from the overflow of streams, rivers, and other waters
of this commonwealth.
Any land area susceptible to inundation by water from any
natural source or as delineated by the applicable Department of Housing
and Urban Development, Federal Insurance Administration Flood Hazard
Boundary Map as being a special flood hazard area.
The channel of a watercourse and those portions of the adjoining
floodplains which are reasonably required to carry and discharge the
one-hundred-year frequency flood. Unless otherwise specified, the
boundary of the floodway is as indicated on maps and flood insurance
studies provided by the Federal Emergency Management Agency (FEMA).
In an area where no FEMA maps or studies have defined the boundary
of the one-hundred-year frequency floodway, it is assumed, absent
evidence to the contrary, that the floodway extends from the stream
to 50 feet from the top-of-bank.
The study of landforms associated with river channels and
the processes that form them.
Planning and associated activities necessary for the management
of forest lands. These include timber inventory and preparation of
forest management plans, silvicultural treatment, cutting budgets,
logging road design and construction, timber harvesting, and reforestation.
A vertical distance between the elevation of the design high
water and the top of a dam, levee, tank, basin, swale, or diversion
berm. The space is required as a safety margin in a pond or basin.
A natural or man-made waterway, usually broad and shallow,
covered with erosion-resistant grasses, used to convey surface water.
Water beneath the earth's surface that supplies wells and
springs and is often between saturated soil and rock.
The replenishment of existing natural underground water supplies
from rain or overland flow.
The U.S. Army Corps Of Engineers, Hydrologic Engineering
Center (HEC) – Hydrologic Modeling System (HMS). This model
was used to model the Darby-Cobbs and Crum Creek watersheds during
the Act 167 plan development and was the basis for the standards and
criteria of this article.
Surface waters having quality which exceeds levels necessary
to support propagation of fish, shellfish, and wildlife and recreation
in and on the water by satisfying Pennsylvania Code Title 25 Environmental
Protection, Chapter 93, Water Quality Standards, § 93.4b(a).
Areas where land use or activities generate highly contaminated
runoff, with concentrations of pollutants in excess of those typically
found in stormwater.
A graph representing the discharge of water versus time for
a selected point in the drainage system.
The hydrologic cycle or balance that sustains quality and
quantity of stormwater, baseflow, storage and groundwater supplies
under natural conditions.
A classification of soils by the Natural Resources Conservation
Service (NRCS), formerly the Soil Conservation Service (SCS), into
four runoff potential groups. The groups range from A soils, which
are very permeable and produce little runoff, to D soils, which are
not very permeable and produce much more runoff.
A surface that prevents the infiltration of water into the
ground. Impervious surfaces include, but are not limited to, streets,
sidewalks, pavements, driveway areas, or roofs. Any surface areas
designed to be gravel or crushed stone shall be regarded as impervious
surfaces.
A retention or detention basin designed to retain stormwater
runoff and release it at a controlled rate.
Development that occurs on smaller parcels that remain undeveloped
but are within or in very close proximity to urban or densely developed
areas. Infill development usually relies on existing infrastructure
and does not require an extension of water, sewer, or other public
utilities.
Movement of surface water into the soil, where it is absorbed
by plant roots, evaporated into the atmosphere, or percolated downward
to recharge groundwater.
A structure designed to direct runoff into the underground
water (e.g., French drains, seepage pits, or seepage trenches).
The flow entering the stormwater management facility and/or
BMP.
The upstream end of any structure through which water may
flow.
A stream that flows only part of the time. Flow generally
occurs for several weeks or months in response to seasonal precipitation
or groundwater discharge.
The lowest surface, the floor or bottom of a culvert, drain,
sewer, channel, basin, BMP, or orifice.
Any of the following activities:
The improvement of one lot or two or more contiguous
lots, tracts, or parcels of land for any purpose involving:
A group of two or more residential or nonresidential
buildings, whether proposed initially or cumulatively, or a single
nonresidential building on a lot or lots regardless of the number
of occupants or tenure; or
The division or allocation of land or space,
whether initially or cumulatively, between or among two or more existing
or prospective occupants by means of, or for the purpose of, streets,
common areas, leaseholds, condominiums, building groups, or other
features.
A subdivision of land.
Development in accordance with § 503(1.1)
of the PA Municipalities Planning Code.
A soil horizon or condition in the soil profile or underlying
strata that includes one of the following:
A seasonal high water table, whether perched
or regional, determined by direct observation of the water table or
indicated by soil mottling.
A rock with open joints, fracture or solution
channels, or masses of loose rock fragments, including gravel, with
insufficient fine soil to fill the voids between the fragments.
A rock formation, other stratum, or soil condition
that is so slowly permeable that it effectively limits downward passage
of water.
A designated parcel, tract, or area of land established by
a plat or otherwise as permitted by law and to be used, developed,
or built upon as a unit.
Any stream segment or other runoff conveyance used as a reach
in watershed-specific hydrologic models.
A method for calculation of velocity of flow (e.g., feet
per second) and flow rate (e.g., cubic feet per second) in open channels
based upon channel shape, roughness, depth of flow, and slope. "Open
channels" may include closed conduits so long as the flow is not under
pressure.
The maximum (largest) design storm that is controlled by
the stormwater facility.
A professional engineer licensed as such in the Commonwealth
of Pennsylvania, duly appointed as the Engineer for a municipality,
planning agency, or joint planning commission.
Haverford Township, Delaware County, Pennsylvania.
Predevelopment condition.
See "hydrologic regime."
Undisturbed surface area or depression where stormwater collects
and a portion of which infiltrates and replenishes the underground
and groundwater.
Pollution that enters a water body from diffuse origins in
the watershed and does not result from discernible, confined, or discrete
conveyances.
Water flowing in stormwater collection facilities, such as
pipes or swales, which is not the result of a rainfall event or snowmelt.
Methods of controlling stormwater runoff quantity and quality,
such as innovative site planning, impervious area and grading reduction,
protection of natural depression areas, temporary ponding on site,
and other techniques.
National Pollutant Discharge Elimination System, the federal
government's system for issuance of permits under the Clean Water
Act, which is delegated to DEP in Pennsylvania.
Natural Resource Conservation Service (previously SCS).
A conveyance channel that is not enclosed.
"Point source," as described in 40 CFR § 122.2,
at the point where Haverford Township's storm sewer system discharges
to surface waters of the commonwealth.
The flow exiting the stormwater management facility and/or
BMP.
Points of water disposal to a stream, river, lake, tidewater,
or artificial drain.
The parcel of land from which a land development or subdivision
originates, determined from the date of municipal adoption of this
article.
Involves the use of parking areas as temporary impoundments
with controlled release rates during rainstorms.
The maximum rate of stormwater runoff from a specific storm
event.
The computer-based hydrologic model developed at Pennsylvania
State University.
A culvert, closed conduit, or similar structure (including
appurtenances) that conveys stormwater.
The Planning Commission of Haverford Township.
Any discernible, confined, and discrete conveyance, including
but not limited to any pipe, ditch, channel, tunnel or conduit from
which stormwater is or may be discharged, as defined in state regulations
at 25 Pennsylvania Code § 92.1.
Period after construction during which disturbed areas are
stabilized, stormwater controls are in place and functioning, and
all proposed improvements in the approved land development plan are
completed.
Prior to commencing construction activities.
Undeveloped/natural condition.
Techniques employed in stormwater BMPs to provide storage or filtering to trap coarse materials and other pollutants before they enter the system, but not necessarily designed to meet the water quality volume requirements of § 78-35.
The specific area of land where any regulated activities
in Haverford Township are planned, conducted or maintained.
A rainfall-runoff relation used to estimate peak flow.
Any stream segment or other runoff conveyance used in the
watershed-specific hydrologic models.
The replenishment of groundwater through the infiltration
of rainfall, other surface waters, or land application of water or
treated wastewater.
Demolition and subsequent rebuilding of impervious surface.
Original documents revised to suit the as-built conditions
and subsequently provided by the engineer to the client. The engineer
reviews the contractor's as-builts against his/her own records for
completeness, then either turns these over to the client or transfers
the information to a set of reproducibles, in both cases for the client's
permanent records.
Any development that requires demolition or removal of existing
structures or impervious surfaces at a site and replacement with new
impervious surfaces. Maintenance activities such as top-layer grinding
and repaving are not considered to be redevelopment. Interior remodeling
projects and tenant improvements are also not considered to be redevelopment.
Actions or proposed actions that have an impact on stormwater runoff quality or quantity and that are specified in § 78-17 of this article.
Defined under NPDES Phase II regulations as earth disturbance
activity of one acre or more with a point source discharge to surface
waters or Haverford Township's storm sewer system or five acres or
more regardless of the planned runoff. This includes earth disturbance
on any portion of, part, or during any stage of a larger common plan
of development.
The percentage of existing conditions' peak rate of runoff
from a site or subarea to which the proposed conditions' peak rate
of runoff must be reduced to protect downstream areas.
Replacement of the impervious surface that does not involve
reconstruction of an existing paved (impervious) surface.
Reconstruction of and full replacement of an existing paved
(impervious) surface.
A structure in which stormwater is stored and not released
during the storm event. Retention basins are designed for infiltration
purposes and do not have an outlet. The retention basin must infiltrate
stored water in four days or less.
The average interval, in years, within which a storm event
of a given magnitude can be expected to recur. For example, the twenty-five-year-return-period
rainfall would be expected to recur on the average of once every 25
years.
A vertical pipe extending from the bottom of a pond that
is used to control the discharge rate from the pond for a specified
design storm.
Earth disturbance activities within the existing road cross
section, such as grading and repairing existing unpaved road surfaces,
cutting road banks, cleaning or clearing drainage ditches, and other
similar activities.
A drainage conduit or pipe that collects water runoff from
a roof and leads it away from the structure.
The temporary ponding and gradual release of stormwater falling
directly onto flat roof surfaces using controlled-flow roof drains
in building designs.
Any part of precipitation that flows over the land surface.
Subdivision and Land Development Ordinance.
A barrier, dam, or retention or detention basin located and
designed in such a way as to retain rock, sand, gravel, silt, or other
material transported by water during construction.
The placement, discharge, or any other introduction of sediment
into the waters of the commonwealth.
The process by which mineral or organic matter is accumulated
or deposited by the movement of water or air.
An area of excavated earth filled with loose stone or similar
coarse material into which surface water is directed for infiltration
into the underground water.
A conveyance or system of conveyances (including roads with
drainage systems, municipal streets, catch basins, curbs, gutters,
ditches, man-made channels, or storm drains) primarily used for collecting
and conveying stormwater runoff.
Stormwater runoff flowing in shallow, defined ruts prior
to entering a defined channel or waterway.
A flow process associated with broad, shallow water movement
on sloping ground surfaces that is not channelized or concentrated.
A method of runoff computation developed by NRCS that is
based on relating soil type and land use/cover to a runoff parameter
called curve number (CN).
The zone through which contaminants, if present, are likely
to migrate and reach a drinking water well or surface water intake.
Watersheds that have been designated by DEP as EV or HQ waters.
A conveyance that is used to pass the peak discharge of the
maximum design storm that is controlled by the stormwater facility.
A reservoir routing procedure based on solution of the continuity
equation (inflow minus outflow equals the change in storage) with
outflow defined as a function of storage volume and depth.
The number of times that a given storm "event" occurs or
is exceeded on the average in a stated period of years (see "return
period").
A system of pipes and/or open channels that conveys intercepted
runoff and stormwater from other sources but excludes domestic sewage
and industrial wastes.
The surface runoff generated by precipitation reaching the
ground surface.
Those subareas of a watershed in which some type of detention
is required to meet the plan requirements and the goals of Act 167.
Any structure, natural or man-made, that, due to its condition,
design or construction, conveys, stores or otherwise affects stormwater
runoff quality, rate, or quantity. Typical stormwater management facilities
include, but are not limited to, detention and retention basins, open
channels, storm sewers, pipes and infiltration structures.
The watershed plan, known as the "Darby and Cobbs Creeks
Watershed Act 167 Stormwater Management Plan," for managing those
land use activities that will influence stormwater runoff quality
and quantity and that would impact the Darby and Cobbs Creeks watershed
adopted by Delaware County, Chester County, Montgomery County and
Philadelphia County as required by the Act of October 4, 1978, P.L.
864 (Act 167).
The plan prepared by the applicant or his representative
indicating how stormwater runoff will be managed at the particular
site of interest according to this article.
A natural watercourse.
The land area adjacent to each side of a stream essential
to maintaining water quality (see "buffer").
A bridge, culvert, or other structure in excess of 100 feet
in length upstream to downstream which encloses a regulated water
of the commonwealth.
The smallest drainage unit of a watershed for which stormwater
management criteria have been established in the stormwater management
plan.
The division or redivision of a lot, tract, or parcel of
land by any means into two or more lots, tracts, parcels, or other
divisions of land including changes in existing lot lines for the
purpose, whether immediate or future, of lease, partition by the court
for distribution to heirs or devisees, transfer of ownership, or building
or lot development; provided, however, that the subdivision by lease
of land for agricultural purposes into parcels of more than 10 acres
not involving any new street or easement of access or any residential
dwelling shall be exempted.
Any and all rivers, streams, creeks, rivulets, ditches, watercourses,
storm sewers, lakes, dammed water, wetlands, ponds, springs, and all
other bodies or channels of conveyance of surface waters, or parts
thereof, whether natural or artificial, within or on the boundaries
of the commonwealth.
A low-lying stretch of land that gathers or carries surface
water runoff.
See "forest management."
The time required for surface runoff to travel from the hydraulically
most distant point of the watershed to a point of interest within
the watershed. This time is the combined total of overland flow time
and flow time in pipes or channels, if any.
Highest point of elevation in a stream channel cross section
at which a rising water level just begins to flow out of the channel
and over the floodplain.
Natural condition (see also "predevelopment condition").
Seasonal depressional wetlands that are covered by shallow
water for variable periods from winter to spring but may be completely
dry for most of the summer and fall.
A channel or conveyance of surface water having a defined
bed and banks, whether natural or artificial, with perennial or intermittent
flow.
Any and all rivers, streams, creeks, rivulets, ditches, watercourses,
storm sewers, lakes, dammed water, wetlands, ponds, springs, and all
other bodies or channels of conveyance of surface and underground
water, or parts thereof, whether natural or artificial, within or
on the boundaries of the commonwealth.
Region or area drained by a river, watercourse, or other
body of water, whether natural or artificial.
The surface and subsurface area surrounding a water supply
well, well field, or spring supplying a public water system through
which contaminants are reasonably likely to move toward and reach
the water source.
Pond for urban runoff management that is designed to detain
urban runoff and always contains water.
Those areas that are inundated or saturated by surface or
groundwater at a frequency and duration sufficient to support, and
that under normal circumstances do support, a prevalence of vegetation
typically adapted for life in saturated soil conditions. Wetlands
generally include swamps, marshes, bogs, fens and similar areas.
A natural ground cover with more than one viable tree of
a DBH of six inches or greater per 1,500 square feet which existed
within three years of application; a cover condition for which SCS
curve numbers have been assigned or to which equivalent rational method
runoff coefficients have been assigned.
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 activity may not proceed
until the property owner or applicant or his/her agent has received
written approval of a drainage plan from Haverford Township and an
adequate erosion and sediment control plan review by the Conservation
District.
The drainage plan shall consist of a general description of the project including sequencing items described in § 78-33, calculations, maps, and plans. A note on the maps shall refer to the associated computations and erosion and sediment control plan by title and date. The cover sheet of the computations and erosion and sediment control plan shall refer to the associated maps by title and date. All drainage plan materials shall be submitted to Haverford Township in a format that is clear, concise, legible, neat, and well organized; otherwise, the drainage plan shall not be accepted for review and shall be returned to the applicant. The following items shall be included in the drainage plan:
A.
General.
(2)
General description of proposed permanent stormwater
management techniques, including construction specifications of the
materials to be used for stormwater management facilities.
(3)
Complete hydrologic, hydraulic, and structural computations
for all stormwater management facilities.
(4)
An erosion and sediment control plan, including all
reviews and letters of adequacy from the Conservation District.
(5)
A general description of proposed nonpoint source
pollution controls.
(6)
The Drainage Plan Application and completed fee schedule
form and associated fee (Appendix C-1).[1]
[1]
Editor's Note: Said Appendix C-1 is included at the end of this chapter.
(7)
The Drainage Plan Checklist (Appendix C-2).[2]
[2]
Editor's Note: Said Appendix C-2 is included at the end of this chapter.
B.
Maps. Map(s) of the project area shall be submitted
on twenty-four-inch by thirty-six-inch sheets and/or shall be prepared
in a form that meets the requirements for recording at the offices
of the Recorder of Deeds of Delaware County. If the SALDO has more
stringent criteria than this article, then the more stringent criteria
shall apply. The contents of the map(s) shall include, but not be
limited to:
(1)
The location of the project relative to highways,
municipal boundaries, or other identifiable landmarks.
(2)
Existing contours at intervals of two feet.
(3)
Existing streams, lakes, ponds, or other waters of
the commonwealth within the project area.
(4)
Other physical features including flood hazard boundaries,
stream buffers, existing drainage courses, areas of natural vegetation
to be preserved, and the total extent of the upstream area draining
through the site.
(5)
The locations of all existing and proposed utilities,
sanitary sewers, and water lines within 50 feet of property lines.
(6)
An overlay showing soil names and boundaries.
(7)
Limits of earth disturbance, including the type and
amount of impervious area that would be added.
(8)
Proposed structures, roads, paved areas, and buildings.
(9)
Final contours at intervals of two feet.
(10)
The name of the development, the name and address
of the owner of the property, and the name of the individual or firm
preparing the plan.
(11)
The date of submission.
(12)
A graphic and written scale of one inch equals
no more than 50 feet; for tracts of 20 acres or more, the scale shall
be one inch equals no more than 100 feet.
(13)
A north arrow.
(14)
The total tract boundary and size with distances
marked to the nearest foot and bearings to the nearest degree.
(15)
Existing and proposed land use(s).
(16)
A key map showing all existing man-made features
beyond the property boundary that would be affected by the project.
(17)
Location of all open channels.
(18)
Overland drainage patterns and swales.
(19)
A fifteen-foot-wide access easement around all
stormwater management facilities that would provide ingress to and
egress from a public right-of-way.
(20)
The location of all erosion and sediment control
facilities.
(21)
A note on the plan indicating the location and
responsibility for maintenance of stormwater management facilities
that would be located off site.
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All off-site facilities shall meet the performance
standards and design criteria specified in this article.
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(22)
A statement, signed by the applicant, acknowledging
that any revision to the approved drainage plan must be approved by
Haverford Township, and that a revised erosion and sediment control
plan must be submitted to the Conservation District for a determination
of adequacy.
(23)
The following signature block for the design
engineer:
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"I, (Design Engineer), on this date (date of
signature), hereby certify that the drainage plan meets all design
standards and criteria of the Haverford Township Stormwater Management
Code."
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C.
Supplemental information to be submitted to Haverford
Township.
(1)
A written description of the following information
shall be submitted by the applicant and shall include:
(2)
An erosion and sediment control plan.
(3)
A description of the effect of the project (in terms
of runoff volumes and peak flows) on adjacent properties and on any
existing municipal stormwater collection system that may receive runoff
from the project site.
(4)
A declaration of adequacy and highway occupancy permit
from the Pennsylvania Department of Transportation (PennDOT) District
office when utilization of a PennDOT storm drainage system is proposed.
D.
Stormwater management facilities.
(1)
All stormwater management facilities must be located
on a plan and described in detail.
(2)
When infiltration measures such as seepage pits, beds
or trenches are used, the locations of existing and proposed septic
tank infiltration areas and wells must be shown.
(3)
All calculations, assumptions, and criteria used in
the design of the stormwater management facilities must be shown.
Haverford Township shall require receipt of
a complete drainage plan, as specified in this article.
A.
Proof of application or documentation of required
permit(s) or approvals for the programs listed below shall be part
of the plan:
C.
For projects that require SALDO approval, the drainage
plan shall be submitted by the applicant as part of the preliminary
plan submission where applicable for the regulated activity.
D.
For regulated activities that do not require SALDO approval, see § 78-24, General drainage plan requirements.
E.
Six copies of the drainage plan shall be submitted
and distributed as follows:
F.
Any submissions to the agencies listed above that
are found to be incomplete shall not be accepted for review and shall
be returned to the applicant with a notification in writing of the
specific manner in which the submission is incomplete.
A.
The municipal Engineer shall review the drainage plan
for consistency with this article and the respective Act 167 stormwater
management plan. Any found incomplete shall not be accepted for review
and shall be returned to the applicant.
B.
The municipal Engineer shall review the drainage plan
for any subdivision or land development against the municipal SALDO
provisions not otherwise superseded by this article.
C.
The Conservation District, in accordance with established
criteria and procedures, shall review the drainage plan for consistency
with stormwater management and erosion and sediment pollution control
requirements and provide comments to Haverford Township. Such comments
shall be considered by Haverford Township prior to final approval
of the drainage plan.
D.
For activities regulated by this article, the municipal
Engineer shall notify the applicant and Haverford Township in writing
whether the drainage plan is consistent with the stormwater management
plan.
(1)
If the municipal Engineer determines that the drainage
plan is consistent with the stormwater management plan, the municipal
Engineer shall forward a letter of consistency to the municipal Secretary
who will then forward a copy to the applicant.
(2)
If the municipal Engineer determines that the drainage
plan is inconsistent or noncompliant with the stormwater management
plan, the municipal Engineer shall forward a letter to the municipal
Secretary with a copy to the applicant citing the reason(s) and specific
Code sections for the inconsistency or noncompliance. Inconsistency
or noncompliance may be due to inadequate information to make a reasonable
judgment as to compliance with the stormwater management plan. Any
drainage plans that are inconsistent or noncompliant may be revised
by the applicant and resubmitted when consistent with this article.
The municipal Secretary shall then notify the applicant of the municipal
Engineer's findings. Any inconsistent or noncompliant drainage plans
may be revised by the applicant and resubmitted consistent with this
article.
E.
For regulated activities specified in § 78-17 of this article that require a building permit, the municipal Engineer shall notify the municipal Building Permit Officer in writing whether the drainage plan is consistent with the stormwater management plan. The municipal Building Permit Officer shall forward a copy of the consistency/inconsistency letter to the applicant. Any drainage plan deemed inconsistent may be revised by the applicant and resubmitted consistent with this article.
F.
For regulated activities under this article that require
an NPDES permit application, the applicant shall forward a copy of
the municipal Engineer's letter stating that the drainage plan is
consistent with the stormwater management plan to the Conservation
District. DEP and the Conservation District may consider the municipal
Engineer's review comments in determining whether to issue a permit.
G.
Haverford Township shall not grant preliminary or final approval to any subdivision or land development for regulated activities specified in § 78-17 of this article if the drainage plan has been found by the municipal Engineer to be inconsistent with the stormwater management plan. All required permits from DEP must be obtained prior to approval of any subdivision or land development.
H.
No building permits for any regulated activity specified in § 78-17 of this article shall be approved by Haverford Township if the drainage plan has been found to be inconsistent with the stormwater management plan, as determined by the municipal Engineer and Conservation District, or without considering the comments of the municipal Engineer and Conservation District. All required permits from DEP must be obtained prior to issuance of a building permit.
I.
The Applicant shall be responsible for completing
record drawings of all stormwater management facilities included in
the approved drainage plan. The record drawings and an explanation
of any discrepancies with the design plans shall be submitted to the
municipal Engineer for final approval. In no case shall Haverford
Township approve the record drawings until Haverford Township receives
a copy of an approved declaration of adequacy and/or highway occupancy
permit from the PennDOT District office, NPDES permit, and any other
applicable permits or approvals from DEP or the Conservation District.
The above permits and approvals must be based on the record drawings.
J.
Haverford Township's approval of a drainage plan shall be valid for a period not to exceed five years commencing on the date that Haverford Township signs the approved drainage plan. If stormwater management facilities included in the approved drainage plan have not been constructed, or if constructed, record drawings of these facilities have not been approved within this five-year time period, then Haverford Township may consider the drainage plan inconsistent or noncompliant and may revoke any and all permits. Drainage plans that are determined to be inconsistent or noncompliant by Haverford Township shall be resubmitted in accordance with § 78-29 of this article.
A.
A modification to a submitted drainage plan under review by Haverford Township for a development site that involves the following shall require a resubmission to Haverford Township of a modified drainage plan consistent with § 78-26 of this article and be subject to review as specified in § 78-27 of this article:
B.
A modification to an already approved or inconsistent
or noncompliant drainage plan shall be submitted to Haverford Township,
accompanied by the applicable municipal review and inspection fee.
A modification to a drainage plan for which a formal action has not
been taken by Haverford Township shall be submitted to Haverford Township
accompanied by the applicable municipal review and inspection fee.
An inconsistent or noncompliant drainage plan may be resubmitted with the revisions addressing the municipal Engineer's concerns documented in writing. It must be addressed to the municipal Secretary in accordance with § 78-26 of this article, distributed accordingly, and be subject to review as specified in § 78-27 of this article. The applicable municipal review and inspection fee must accompany a resubmission of an inconsistent or noncompliant drainage plan.
A.
Applicants proposing regulated activities in Haverford Township which do not fall under the exemption criteria shown in § 78-18 shall submit a drainage plan consistent with this article and the respective stormwater management plan to Haverford Township for review. The stormwater management criteria of this article shall apply to the total proposed development even if development is to take place in stages.
B.
The applicant is required to find practicable alternatives
to the surface discharge of stormwater, the creation of impervious
surfaces, and the degradation of waters of the commonwealth and must
maintain as much as possible the natural hydrologic regime.
C.
The drainage plan must be designed consistent with the sequencing provisions of § 78-33 to ensure maintenance of the natural hydrologic regime, to promote groundwater recharge, and to protect groundwater and surface water quality and quantity. The drainage plan designer must proceed sequentially in accordance with this article.
D.
Stormwater drainage systems shall be designed in order
to permit unimpeded flow along natural watercourses, except as modified
by stormwater management facilities or open channels consistent with
this article.
E.
Existing points of concentrated drainage that discharge
onto adjacent property shall not be altered in any manner which could
cause property damage without permission of the affected property
owner(s) and shall be subject to any applicable discharge criteria
specified in this article.
F.
Areas of existing diffused drainage discharge, whether
proposed to be concentrated or maintained as diffused drainage areas,
shall be subject to any applicable discharge criteria in the general
direction of existing discharge, except as otherwise provided by this
article. If diffused drainage discharge 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 impacts will result from the concentrated discharge.
G.
Where a development site is traversed by existing streams, drainage easements shall be provided conforming to the line of such streams. The terms of the easement shall conform to the stream buffer requirements contained in § 78-35G of this article.
H.
Any stormwater management facilities regulated by
this article that would be located in or adjacent to waters of the
commonwealth or delineated wetlands shall be subject to approval by
DEP through the joint permit application or the environmental assessment
approval process or, where deemed appropriate, by the DEP general
permit process. When there is a question as to whether wetlands may
be involved, it is the responsibility of the applicant or his agent
to show that the land in question cannot be classified as wetlands;
otherwise, approval to work in the area must be obtained from DEP.
I.
Any proposed stormwater management facilities regulated
by this article that would be located on state highway rights-of-way
shall be subject to approval by PennDOT.
J.
Minimization of impervious surfaces and infiltration
of runoff through seepage beds, infiltration trenches, etc., is encouraged
where soil conditions permit in order to reduce the size or eliminate
the need for detention facilities or other structural BMPs.
K.
All stormwater runoff shall be pretreated for water
quality prior to discharge to surface or groundwater.
L.
All regulated activities within Haverford Township
shall be designed, implemented, operated, and maintained to meet the
purposes of this article through these two elements:
M.
No regulated earth disturbance activities within Haverford
Township shall commence until the requirements of this article are
met.
O.
Operations and maintenance of permanent stormwater
BMPs shall be addressed as required by this article.
P.
All BMPs used to meet the requirements of this article
shall conform to the state water quality requirements and any more
stringent requirements as set forth by Haverford Township.
Q.
Techniques described in Appendix E[1] (Low Impact Development) of this article shall be considered
because they reduce the costs of complying with the requirements of
this article and the state water quality requirements.
[1]
Editor's Note: Said appendix is included at the end of this chapter.
R.
In selecting the appropriate BMPs or combinations
thereof, the applicant shall consider the following:
(1)
Total contributing area.
(2)
Permeability and infiltration rate of the site's soils.
(3)
Slope and depth to bedrock.
(4)
Seasonal high water table.
(5)
Proximity to building foundations and wellheads.
(6)
Erodibility of soils.
(7)
Land availability and configuration of the topography.
(8)
Peak discharge and required volume control.
(9)
Streambank erosion.
(10)
Efficiency of the BMPs to mitigate potential
water quality problems.
(11)
The volume of runoff that will be effectively
treated.
(12)
The nature of the pollutant being removed.
(13)
Maintenance requirements.
(14)
Creation/protection of aquatic and wildlife
habitat.
(15)
Recreational value.
S.
The applicant may meet the stormwater management criteria
through off-site stormwater management measures as long as the proposed
measures are in the same subwatershed as shown in Appendix A.[2]
[2]
Editor's Note: Appendix A, Darby-Cobbs Stormwater Management District Watershed Map, is included at the end of this chapter.
The following permit requirements may apply
to certain regulated earth disturbance activities and must be met
prior to commencement of regulated earth disturbance activities, as
applicable:
A.
All regulated earth disturbance activities subject
to permit requirements by DEP under regulations at 25 Pennsylvania
Code Chapter 102.
B.
Work within natural drainageways subject to permit
by DEP under 25 Pennsylvania Code Chapter 105.
C.
Any stormwater management facility that would be located
in or adjacent to surface waters of the commonwealth, including wetlands,
subject to permit by DEP under 25 Pennsylvania Code Chapter 105.
D.
Any stormwater management facility that would be located
on a state highway right-of-way or require access from a state highway
shall be subject to approval by PennDOT.
E.
Culverts, bridges, storm sewers, or any other facilities
which must pass or convey flows from the tributary area and any facility
which may constitute a dam, subject to permit by DEP under 25 Pennsylvania
Code Chapter 105.
A.
No regulated earth disturbance activities within Haverford
Township shall commence until Haverford Township receives an approval
from the Conservation District of an erosion and sediment control
plan for construction activities.
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 Pennsylvania Code § 102.4(b).
C.
In addition, under 25 Pennsylvania Code Chapter 92,
a DEP "NPDES construction activities" permit is required for regulated
earth disturbance activities. 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
Haverford Township.
D.
A copy of the erosion and sediment control plan and
any required permit, as required by DEP regulations, shall be available
on the project site at all times.
E.
Additional erosion and sediment control design standards
and criteria are recommended to be applied where infiltration BMPs
are proposed. They shall include the following:
(1)
Areas proposed for infiltration BMPs shall be protected
from sedimentation and compaction during the construction phase to
maintain maximum infiltration capacity.
(2)
Infiltration BMPs shall not be constructed nor receive
runoff until the entire drainage area contributory to the infiltration
BMP has achieved final stabilization.
A.
The design of all regulated activities shall include
the following to minimize stormwater impacts.
(1)
The applicant shall find practicable alternatives
to the surface discharge of stormwater, such as those listed in Appendix
F,[1] Table F-5, the creation of impervious surfaces, and the
degradation of waters of the commonwealth and must maintain as much
as possible the natural hydrologic regime of the site.
[1]
Editor's Note: Appendix F, Stormwater Management Design Criteria is included at the end of this chapter.
(2)
An alternative is practicable if it is available and
capable of implementation after taking into consideration existing
technology and logistics in light of overall project purposes and
other municipal requirements.
(3)
All practicable alternatives to the discharge of stormwater
are presumed to have less adverse impact on quantity and quality of
waters of the commonwealth unless otherwise demonstrated.
B.
The applicant shall demonstrate that the regulated
activities were designed in the following sequence. The goal of the
sequence is to minimize the increases in stormwater runoff and impacts
to water quality resulting from the proposed regulated activity:
(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, stream buffers and hydrologic soil groups. Land
development, any existing recharge areas, and other requirements outlined
in the municipal SALDO shall also be included.
(4)
Identify site-specific existing conditions drainage
areas, discharge points, recharge areas, and hydrologic soil groups
A and B (areas conducive to infiltration).
(6)
Satisfy the groundwater recharge (infiltration) objective (§ 78-34) and provide for stormwater pretreatment prior to infiltration.
(8)
Provide streambank erosion protection in accordance with § 78-36 streambank erosion requirements.
(9)
Determine into what management district the site falls
(Appendix A[2]) and conduct an existing conditions runoff analysis.
[2]
Editor's Note: Appendix A is included at the end of this chapter.
(10)
Prepare final project design to maintain existing
conditions drainage areas and discharge points, to minimize earth
disturbance and impervious surfaces and, to the maximum extent possible,
to ensure that the remaining site development has no surface or point
discharge.
(11)
Conduct a proposed conditions runoff analysis based on the final design that meets the management district requirements (§ 78-37).
(12)
Manage any remaining runoff prior to discharge
through detention, bioretention, direct discharge or other structural
control.
Maximizing the groundwater recharge capacity of the area being developed is required. Design of the infiltration facilities shall consider groundwater recharge to compensate for the reduction in the recharge that occurs when the ground surface is disturbed or impervious surface is created. It is recommended that roof runoff be directed to infiltration BMPs that may be designed to compensate for the runoff from parking areas. These measures are required to be consistent with § 78-15 and to take advantage of utilizing any existing recharge areas. Infiltration may not be feasible on every site due to site-specific limitations such as soil type. If it cannot be physically accomplished, then the design professional shall be responsible to show that this cannot be physically accomplished. If it can be physically accomplished, then the volume of runoff to be infiltrated shall be determined from § 78-34A(2) depending on demonstrated site conditions and shall be the greater of the volumes.
A.
Infiltration BMPs shall meet the following minimum
requirements:
(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 top of the limiting zone.
(b)
An infiltration rate sufficient to accept the
additional stormwater load and dewater completely as determined by
field tests conducted by the applicant's design professional.
(c)
The infiltration facility shall be capable of
completely infiltrating the retention (infiltration) volume (Rev) below grade within four days (96 hours).
(d)
Pretreatment shall be provided prior to infiltration.
(2)
The size of the infiltration facility shall be based
upon the following volume criteria:
(a)
Net two-year volume approach. In HQ/EV watersheds,
the retention (infiltration) volume (Rev) to
be captured and infiltrated shall be the net two-year volume. The
net two-year volume shall be determined by plotting the two-year project
site postdevelopment hydrograph, drawing a straight line from the
point-of-inflection of the rising limb of the hydrograph to the predevelopment
two-year storm, and measuring the volume under the curve as shown
in Figure 405.1.
 |
(b)
One inch from impervious surface. In other portions
of the watershed that are not classified as HQ/EV, the retention (infiltration)
volume (Rev) will be equal to capturing one
inch of rainfall over all proposed impervious surfaces.
|
Rev = I * impervious area square feet @ 12 (inches)
= cubic feet (cf)
| ||
|---|---|---|
|
An asterisk (*) in equations denotes multiplication.
| ||
(c)
Obtaining the Rev volume in § 78-34A(2)(a), above, may not be feasible on every site due to site-specific limitations such as soil type. If it cannot be physically accomplished, then the design professional shall be responsible for showing that this cannot be physically accomplished. If it cannot be physically accomplished, then the retention (infiltration) volume Rev required shall be as much as can be physically accomplished with a minimum of 0.50 inch depending on demonstrated site conditions. It has been determined that capturing and infiltrating 0.50 inch of runoff from the impervious areas will aid in maintaining the hydrologic regime (baseflow) of the watershed. If the goals of § 78-34A(2)(a) or (b) cannot be achieved, then 0.50 inch of rainfall shall be retained and infiltrated from all impervious areas.
|
The minimum recharge volume (Rev) required would, therefore, be computed as:
| ||||
|
Rev * impervious area
(square feet) @ 12 (inches) = cubic feet (cf)
| ||||
|
An asterisk (*) in equations denotes multiplication.
| ||||
|
Where:
| ||||
|
I
|
=
|
The maximum equivalent infiltration amount (inches)
that the site can physically accept or 0.50 inch, whichever is greater.
| ||
|
The retention volume values derived from the methods in § 78-34A(2)(a), is the minimum volume the applicant must control through an infiltration BMP facility. However, if a site has areas of soils where additional volume of retention can be achieved, the applicant is encouraged to infiltrate as much of the stormwater runoff from the site as possible.
| ||||
|
If the minimum of 0.50 inch of infiltration
requirement cannot be achieved, a waiver from Section 405, Groundwater
Recharge, would be required from Haverford Township.
| ||||
B.
Soils. A detailed soils evaluation of the project
site shall be required to determine the suitability of infiltration
facilities. The evaluation shall be performed by a qualified design
professional and at a minimum address soil permeability, depth to
bedrock, and subgrade stability. The general process for designing
the infiltration BMP shall be:
(1)
Analyze hydrologic soil groups as well as natural
and man-made features within the site to determine general areas of
suitability for infiltration practices. In areas where development
on fill material is under consideration, conduct geotechnical investigations
of subgrade stability; infiltration may not be ruled out without conducting
these tests.
(2)
Provide field tests such as double ring infiltrometer
or hydraulic conductivity tests (at the level of the proposed infiltration
surface) to determine the appropriate hydraulic conductivity rate.
If approved, percolation tests may be used for design purposes.
(3)
Design the infiltration structure for the required
retention (Rev) volume based on field-determined
capacity at the level of the proposed infiltration surface.
(4)
If on-lot infiltration structures are proposed by
the applicant's design professional, it must be demonstrated to Haverford
Township that the soils are conducive to infiltrate on the lots identified.
C.
Stormwater hotspots.
(1)
Below is a list of examples of designated hotspots.
If a site is designated as a hotspot, it has important implications
for how stormwater is managed. First and foremost, untreated stormwater
runoff from hotspots shall not be allowed to recharge into groundwater
where it may contaminate water supplies. Therefore, the Rev requirement
shall NOT be applied to development sites that fit into the hotspot
category (the entire WQv must still be treated). Second, a greater
level of stormwater treatment shall be considered at hotspot sites
to prevent pollutant wash off after construction. The Environmental
Protection Agency's (EPA) NPDES stormwater program requires some industrial
sites to prepare and implement a stormwater pollution prevention plan.
(a)
Examples of hotspots:
|
Vehicle salvage yards and recycling facilities
| |
|
Vehicle fueling stations
| |
|
Vehicle service and maintenance facilities
| |
|
Vehicle and equipment cleaning facilities
| |
|
Fleet storage areas (bus, truck, etc.)
| |
|
Industrial sites based on Standard Industrial
Codes
| |
|
Marinas (service and maintenance)
| |
|
Outdoor liquid container storage
| |
|
Outdoor loading/unloading facilities
| |
|
Public works storage areas
| |
|
Facilities that generate or store hazardous
materials
| |
|
Commercial container nursery
| |
|
Other land uses and activities as designated
by an appropriate review authority
|
(b)
The following land uses and activities are not
normally considered hotspots:
|
Residential streets and rural highways
| |
|
Residential development
| |
|
Institutional development
| |
|
Office developments
| |
|
Nonindustrial rooftops
| |
|
Pervious areas, except golf courses and nurseries
[which may need an integrated pest management (IPM) plan].
|
(2)
While large highways [average daily traffic volume
(ADT) greater than 30,000] are not designated as stormwater hotspots,
it is important to ensure that highway stormwater management plans
adequately protect groundwater.
D.
Extreme caution shall be exercised where infiltration
is proposed in SWPAs as defined by the local municipality or water
authority.
E.
Infiltration facilities shall be used in conjunction
with other innovative or traditional BMPs, stormwater control facilities,
and nonstructural stormwater management alternatives.
F.
Extreme caution shall be exercised where salt or chloride
(municipal salt storage) would be a pollutant since soils do little
to filter this pollutant, and it may contaminate the groundwater.
The qualified design professional shall evaluate the possibility of
groundwater contamination from the proposed infiltration facility
and perform a hydrogeologic justification study if necessary.
G.
The infiltration requirement in HQ or EV waters shall
be subject to the Department's Chapter 93 Antidegradation Regulations.
H.
An impermeable liner will be required in detention
basins where the possibility of groundwater contamination exists.
A detailed hydrogeologic investigation may be required by Haverford
Township.
I.
Haverford Township shall require the applicant to
provide safeguards against groundwater contamination for land uses
that may cause groundwater contamination should there be a mishap
or spill.
The applicant shall comply with the following
water quality requirements of this article.
A.
No regulated earth disturbance activities within Haverford
Township shall commence until approval by Haverford Township of a
plan which demonstrates compliance with postconstruction state water
quality requirements.
B.
The BMPs shall be designed, implemented, and maintained
to meet state water quality requirements and any other more stringent
requirements as determined by Haverford Township.
C.
To control postconstruction stormwater impacts from
regulated earth disturbance activities, state water quality requirements
can be met by BMPs, including site design, which provide for replication
of preconstruction stormwater infiltration and runoff conditions so
that postconstruction stormwater discharges do not degrade the physical,
chemical, or biological characteristics of the receiving waters. As
described in the DEP Comprehensive Stormwater Management Policy (No.
392-0300-002, September 28, 2002), this may be achieved by the following:
(1)
Infiltration: replication of preconstruction stormwater
infiltration conditions;
(2)
Treatment: use of water quality treatment BMPs to
ensure filtering out of the chemical and physical pollutants from
the stormwater runoff; and
(3)
Streambank and streambed protection: management of
volume and rate of postconstruction stormwater discharges to prevent
physical degradation of receiving waters (e.g., from scouring).
D.
Developed areas shall provide adequate storage and treatment facilities necessary to capture and treat stormwater runoff. The retention volume computed under § 78-34 may be a component of the water quality volume if the applicant chooses to manage both components in a single facility. If the retention volume is less than the water quality volume, the remaining water quality volume may be captured and treated by methods other than infiltration BMPs. The required water quality volume (WQv) is the storage capacity needed to capture and treat a portion of stormwater runoff from the developed areas of the site.
(1)
To achieve this goal, the following criterion is established:
(a)
The following calculation formula is to be used
to determine the water quality storage volume (WQv) in acre-feet of
storage required by this article:
|
WQv = [(P)(Rv)(A)] @ 12
| |||
|
WHERE:
| |||
|
WQv
|
=
|
Water quality volume (acre-feet)
| |
|
P
|
=
|
1 inch
| |
|
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)
| |
(b)
This volume requirement can be accomplished
by the permanent volume of a wet basin or the detained volume from
other BMPs. Where appropriate, wet basins shall be utilized for water
quality control and shall follow the guidelines of the BMP manuals
referenced in Appendix G.[1]
[1]
Editor's Note: Appendix G, a bibliography
of reference materials, is on file in the Township's Zoning Office.
(2)
Release of water can begin at the start of the storm
(i.e., the invert of the water quality orifice is at the invert of
the facility). The design of the facility shall provide for protection
from clogging and unwanted sedimentation.
E.
For areas within defined special protection subwatersheds
that include EV and HQ waters, the temperature and quality of water
and streams shall be maintained through the use of temperature-sensitive
BMPs and stormwater conveyance systems.
F.
To accomplish the above, the applicant shall submit
original and innovative designs to the municipal Engineer for review
and approval. Such designs may achieve the water quality objectives
through a combination of different BMPs.
G.
If a perennial or intermittent stream passes through
the site, the applicant shall create a stream buffer extending a minimum
of 50 feet to either side of the top-of-bank of the channel. The buffer
area shall be maintained with and encouraged to use appropriate native
vegetation (refer to Appendix H of the Pennsylvania Handbook of Best
Management Practices for Developing Areas for plant lists). If the
applicable rear or side yard setback is less than 50 feet, the buffer
width may be reduced to 25% of the setback to a minimum of 10 feet.
If an existing buffer is legally prescribed (i.e., deed, covenant,
easement, etc.) and it exceeds the requirements of this article, the
existing buffer shall be maintained. This does not include lakes or
wetlands.
H.
Evidence of any necessary permit(s) for regulated
earth disturbance activities from the appropriate DEP regional office
must be provided to Haverford Township.
A.
In addition to the control of water quality volume
(in order to minimize the impact of stormwater runoff on downstream
streambank erosion), the primary requirement is to design a BMP to
detain the proposed conditions two-year, twenty-four-hour design storm
to the existing conditions one-year flow using the SCS Type II distribution.
Additionally, provisions shall be made (such as adding a small orifice
at the bottom of the outlet structure) so that the proposed conditions
one-year storm takes a minimum of 24 hours to drain from the facility
from a point where the maximum volume of water from the one-year storm
is captured (i.e., the maximum water surface elevation is achieved
in the facility). Release of water can begin at the start of the storm
(i.e., the invert of the water quality orifice is at the invert of
the facility).
B.
The minimum orifice size in the outlet structure to
the BMP shall be three inches in diameter where possible, and a trash
rack shall be installed to prevent clogging. On sites with small drainage
areas contributing to this BMP that do not provide enough runoff volume
to allow a twenty-four-hour attenuation with the three-inch orifice,
the calculations shall be submitted showing this condition. Orifice
sizes less than three inches can be utilized, provided that the design
will prevent clogging of the intake.
C.
In "Conditional Direct Discharge Districts" (District C) only (see § 78-37), the objective is not to attenuate the storms greater than the two-year recurrence interval. This can be accomplished by configuring the outlet structure not to control the larger storms or by a bypass channel that diverts only the two-year stormwater runoff into the basin or conversely, diverts flows in excess of the two-year storm away from the basin.
A.
The Darby and Cobbs Creeks watershed has been divided
into stormwater management districts as shown on the Management District
Map in Appendix A.[1] In addition to the requirements specified in Table 408.1 below, the erosion and sedimentation control (§ 78-32), the nonstructural project design (§ 78-33), the groundwater recharge (§ 78-34), the water quality (§ 78-35), and the streambank erosion (§ 78-36) requirements shall be implemented.
(1)
Standards for managing runoff from each subarea in
the Darby and Cobbs Creeks watershed for the two-, five-, ten-, twenty-five-,
fifty-, and one-hundred-year design storms are shown in Table 408.1.
Development sites located in each of the management districts must
control proposed conditions runoff rates to existing conditions runoff
rates for the design storms in accordance with Table 408.1.
|
TABLE 408.1
| |
|---|---|
|
PEAK RATE CONTROL STANDARDS BY STORMWATER
MANAGEMENT DISTRICT IN THE
DARBY-COBBS CREEK WATERSHED
|
|
District
|
Proposed Condition Design Storm
|
Existing Condition Design Storm
| |
|---|---|---|---|
|
A
|
2 – year
|
1 – year
| |
|
5 – year
|
5 – year
| ||
|
10 – year
|
10 – year
| ||
|
25 – year
|
25 – year
| ||
|
100 – year
|
100 – year
| ||
|
B-1
|
2 – year
|
1 – year
| |
|
10 – year
|
5 – year
| ||
|
25 – year
|
10 – year
| ||
|
50 – year
|
25 – year
| ||
|
100 – year
|
100 – year
| ||
|
B-2
|
2 – year
|
1 – year
| |
|
5 – year
|
2 – year
| ||
|
25 – year
|
5 – year
| ||
|
50 – year
|
10 – year
| ||
|
100 – year
|
100 – year
| ||
|
C
|
Conditional Direct Discharge District
| ||
(2)
In District C, development sites that can discharge
directly to the Darby-Cobbs Creek main channel, major tributaries,
or indirectly to the main channel through an existing stormwater drainage
system (i.e., storm sewer or tributary) may do so without control
of the proposed conditions peak rate of runoff greater than the five-year
storm. Sites in District C will still have to comply with the groundwater
recharge criteria, the water quality criteria, and streambank erosion
criteria. If the proposed conditions runoff is intended to be conveyed
by an existing stormwater drainage system to the main channel, assurance
must be provided that such system has adequate capacity to convey
the flows greater than the two-year existing conditions peak flow
or will be provided with improvements to furnish the required capacity.
When adequate capacity in the downstream system does not exist and
will not be provided through improvements, the proposed conditions
peak rate of runoff must be controlled to the existing conditions
peak rate as required in District A provisions (i.e., ten-year proposed
conditions flows to ten-year existing conditions flows) for the specified
design storms.
[1]
Editor's Note: Appendix A is located at the
end of this chapter.
B.
General. 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 (Appendix A) and
this section of the article.
C.
District boundaries. The boundaries of the stormwater
management districts are shown on an official map that is available
for inspection at the municipal and County Planning offices. A copy
of the official map at a reduced scale is included in Appendix A.
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 the two-foot topographic contours (or most accurate
data required) provided as part of the drainage 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 meet the management district criteria for which the discharge
is located. 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 discharge site. In this case,
peak discharge in any direction may follow Management District A criteria,
provided that the overall site discharge meets the management district
criteria for which the discharge is located.
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. However, on-site drainage
facilities shall be designed to safely convey off-site flows through
the development site.
F.
Site areas. Where the site area to be impacted by
a proposed development activity differs significantly from the total
site area, only the proposed impact area utilizing stormwater management
measures shall be subject to the management district criteria. In
other words, unimpacted areas bypassing the stormwater management
facilities would not be subject to the management district criteria.
G.
"No harm" option. For any proposed development site not located in a Conditional Direct Discharge District, the applicant has the option of using a less-restrictive runoff control (including no detention) if the applicant can prove that "no harm" would be caused by discharging at a higher runoff rate than that specified by the stormwater management plan. The "no harm" option is used when an Applicant can prove that the proposed conditions hydrographs can match existing conditions hydrographs and if it can be proved that the proposed conditions will not cause increases in peaks at all points downstream. Proof of "no harm" must be shown based upon the following downstream impact evaluation which shall include a downstream hydraulic capacity analysis consistent with Subsection H to determine if adequate hydraulic capacity exists. The applicant shall submit to Haverford Township this evaluation of the impacts due to increased downstream stormwater flows in the watershed.
(1)
The hydrologic regime of the site must be maintained.
(2)
The downstream impact evaluation shall include hydrologic
and hydraulic calculations necessary to determine the impact of hydrograph
timing modifications due to the proposed development upon a dam, highway,
structure, natural point of restricted streamflow, or any stream channel
section established with the concurrence of the municipality.
(3)
The evaluation shall continue downstream until the
increase in flow diminishes due to additional flow from tributaries
and/or stream attenuation.
(4)
The peak flow values to be used for downstream areas
for the design return period storms (two-, five-, ten-, fifty-, and
one-hundred-year) shall be the values from the calibrated model for
the respective watershed. These flow values can be obtained from the
original Act 167 watershed stormwater management plans.
(5)
Applicant-proposed runoff controls which would generate increased peak flow rates at storm drainage problem areas would, by definition, be precluded from successful attempts to prove "no-harm," except in conjunction with proposed capacity improvements for the problem areas consistent with Subsection H.
(6)
Financial distress shall not constitute grounds for
the municipality to approve the use of the "no-harm" option.
(7)
Capacity improvements to conveyance facilities or
obstructions may be provided as necessary to implement the "no harm"
option as long as it can be demonstrated through the downstream hydraulic
capacity analysis that the improvements would not create any harm
downstream.
(8)
Any "no harm" justifications shall be submitted by
the applicant as part of the drainage plan submission per this article.
H.
Downstream hydraulic capacity analysis. Any downstream
hydraulic capacity 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 DEP 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.
(3)
Culverts, bridges, storm sewers, or any other facilities
which need to pass or convey flows from the tributary area must be
designed in accordance with DEP Chapter 105 regulations (if applicable)
and, at minimum, pass the increased twenty-five-year return period
runoff.
I.
Alternate criteria for 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 Haverford Township;
A.
Stormwater runoff from all development sites with
a drainage area of greater than 200 acres shall be calculated using
a generally accepted calculation technique that is based on the NRCS
soil cover complex method. Table 409.1 summarizes acceptable computation
methods, and the method selected by the design professional shall
be based on the individual limitations and suitability of each method
for a particular site. Haverford Township may allow the use of the
Rational Method to estimate peak discharges from drainage areas that
contain less than 200 acres. The soil cover complex method shall be
used for drainage areas greater than 200 acres.
|
TABLE 409.1
| |
|---|---|
|
ACCEPTABLE COMPUTATION METHODOLOGIES
FOR STORMWATER MANAGEMENT PLANS
|
|
Method
|
Developed By
|
Applicability
| |
|---|---|---|---|
|
TR-20 (or commercial computer package based
on TR-20)
|
USDA NRCS
|
Applicable where use of full hydrology computer
model is desirable or necessary.
| |
|
TR-55 (or commercial computer package based
on TR-55)
|
USDA NRCS
|
Applicable for land development plans where
limitations described in TR-55.
| |
|
HEC-1/HEC-HMS
|
US Army Corps of Engineers
|
Applicable where use of a full hydrologic computer
is desirable or necessary.
| |
|
PSRM
|
Penn State University
|
Applicable where use of a hydrologic model is
desirable or necessary; simpler than TR-20 or HEC-1.
| |
|
Rational method (or commercial computer package
based on rational method)
|
Emil Kuichling (1889)
|
For sites less than 200 acres, or as approved
by the municipality and/or municipal Engineer.
| |
|
Other methods
|
Varies
|
Other computation methodologies approved by
the municipality and/or municipal Engineer.
| |
|
HEC RAS
|
US Army Corp of Engineers
|
"No harm" option
|
B.
All calculations consistent with this article using
the soil cover complex method shall use the appropriate design rainfall
depths for the various return period storms according to the region
in which they are located as presented in Table F-1 in Appendix F
of this article.[1] If a hydrologic computer model such as PSRM or HEC-1/HEC-HMS
is used for stormwater runoff calculations, then the duration of rainfall
shall be 24 hours. The alternating block method shown in Figure F-1
or the SCS Type II S Curve, Figure F-3 in Appendix F, shall be used
for the rainfall distribution.
[1]
Editor's Note: Appendix F is included at the end of this chapter.
C.
The following criteria shall be used for runoff calculations:
(1)
For development sites not considered redevelopment,
the ground cover used in determining the existing conditions flow
rates shall be as follows:
(a)
Wooded sites shall use a ground cover of "woods
in good condition." Portions of a site having more than one viable
tree of a DBH of six inches or greater per 1,500 square feet shall
be considered "wooded" where such trees existed within three years
of application.
(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 (CN) number or Rational "c" value (i.e., woods) as listed
in Tables F-2 or F-3 in Appendix F of this article.
(2)
For development and redevelopment sites, the ground
cover used in determining the existing conditions flow rates for the
developed portion of the site shall be based upon actual land cover
conditions.
D.
All calculations using the rational method shall use
rainfall intensities consistent with appropriate times-of-concentration
for overland flow and return periods presented in the Region 5 Curves
from the PennDOT Storm-Duration-Frequency Chart (Figure F-4). Times-of-concentration
for overland flow shall be calculated using the methodology presented
in Chapter 3 of Urban Hydrology for Small Watersheds, NRCS, TR-55
(as amended or replaced from time to time by NRCS). Times-of-concentration
for channel and pipe flow shall be computed using Manning's equation.
E.
Runoff curve numbers (CN) for both existing and proposed
conditions to be used in the soil cover complex method shall be obtained
from Table F-2 in Appendix F of this article.
F.
Runoff coefficients (c) for both existing and proposed
conditions for use in the rational method shall be obtained from Table
F-3 in Appendix F of this article.
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 F-4 in Appendix F.
H.
Outlet structures for stormwater management facilities
shall be designed to meet the performance standards of this article
using any generally accepted hydraulic analysis technique or method.
I.
The design of any stormwater detention facilities
intended to meet the performance standards of this article shall be
verified by routing the design storm hydrograph through these facilities
using the storage-indication method. The design storm hydrograph shall
be computed using a calculation method that produces a full hydrograph.
Haverford Township may approve the use of any generally accepted full
hydrograph approximation technique that shall use a total runoff volume
that is consistent with the volume from a method that produces a full
hydrograph.
A.
Any stormwater facility located on state highway rights-of-way
shall be subject to approval by PennDOT.
B.
All wet basin designs shall incorporate biologic controls
consistent with the West Nile Guidance found in Appendix H.[1]
[1]
Editor's Note: Appendix H is included at the end of this chapter.
C.
Any stormwater management facility (i.e., detention
basin) required or regulated by this article designed to store runoff
and requiring a berm or earthen embankment shall be designed to provide
an emergency spillway to handle flow up to and including the one-hundred-year
proposed conditions. The height of embankment must provide a minimum
1.0 foot of freeboard above the maximum pool elevation computed when
the facility functions for the one-hundred-year proposed conditions
inflow. Should any stormwater management facility require a dam safety
permit under DEP Chapter 105, the facility shall be designed in accordance
with Chapter 105 and meet the regulations of Chapter 105 concerning
dam safety. Chapter 105 may be required to pass storms larger than
the one-hundred-year event.
D.
Any facilities that constitute water obstructions
(e.g., culverts, bridges, outfalls, or stream enclosures) and any
work involving wetlands governed by 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.
E.
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. 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.
F.
Any drainage conveyance facility and/or channel not
governed by Chapter 105 regulations must be able to convey, without
damage to the drainage structure or roadway, runoff from the twenty-five-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.
G.
Adequate erosion protection shall be provided along
all open channels and at all points of discharge.
H.
The design of all stormwater management facilities
shall incorporate sound engineering principles and practices. Haverford
Township reserves the right to disapprove any design that would result
in construction in or continuation of a stormwater problem area.
A.
The municipal Engineer or his municipal designee shall
inspect all phases of the installation of the permanent BMPs and/or
stormwater management facilities as deemed appropriate by the municipal
Engineer.
B.
During any stage of the work, if the municipal Engineer
or his municipal designee determines that the permanent BMPs and/or
stormwater management facilities are not being installed in accordance
with the approved stormwater management plan, the municipality shall
revoke any existing permits or other approvals and issue a cease and
desist order until a revised drainage plan is submitted and approved,
as specified in this article, and until the deficiencies are corrected.
C.
A final inspection of all BMPs and/or stormwater management
facilities shall be conducted by the municipal Engineer or his municipal
designee to confirm compliance with the approved drainage plan prior
to the issuance of any occupancy permit.
Fees shall be established by Haverford Township to defray plan review and construction inspection costs incurred by the municipality. All fees shall be paid by the applicant at the time of drainage plan submission. A review and inspection fee schedule shall be established by resolution of the Board of Commissioners based on the size of the regulated activity and based on the municipality's costs for reviewing drainage plans and conducting inspections pursuant to § 78-40. Haverford Township shall periodically update the review and inspection fee schedule to ensure that review costs are adequately reimbursed.
A.
For subdivisions and land developments the applicant
shall provide a financial guarantee to the municipality for the timely
installation and proper construction of all stormwater management
controls as:
B.
For other regulated activities, Haverford Township
may require a financial guarantee from the applicant.
A.
No regulated earth disturbance activities within Haverford
Township shall commence until approval by the municipality of a stormwater
control and BMP operations and maintenance plan that describes how
the permanent (e.g., postconstruction) stormwater controls and BMPs
will be properly operated and maintained.
B.
The following items shall be included in the stormwater
control and BMP operations and maintenance plan:
(1)
Map(s) of the project area, in a form that meets the
requirements for recording at the offices of the Recorder of Deeds
of Delaware County. The contents of the maps(s) shall include, but
not be limited to:
(a)
Clear identification of the location and nature
of permanent stormwater controls and 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 fifteen-foot-wide access easement around all
stormwater controls and BMPs that would provide ingress to and egress
from a public right-of-way.
(2)
A description of how each permanent stormwater control
and BMP will be operated and maintained, and the identity and contact
information associated with 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.
(4)
A statement, signed by the landowner, acknowledging
that the stormwater controls and BMPs are fixtures that can be altered
or removed only after approval by Haverford Township.
C.
The stormwater control and BMP operations and maintenance
plan for the project site shall establish responsibilities for the
continuing operation and maintenance of all permanent stormwater controls
and BMPs, as follows:
(1)
If a plan includes structures or lots which are to
be separately owned and in which streets, sewers, and other public
improvements are to be dedicated to Haverford Township, stormwater
controls and BMPs may also be dedicated to and maintained by the municipality;
(2)
If a plan includes operations and maintenance by a
single ownership or if sewers and other public improvements are to
be privately owned and maintained, then the operation and maintenance
of stormwater controls and BMPs shall be the responsibility of the
owner or private management entity.
D.
Haverford Township shall make the final determination
on the continuing operations and maintenance responsibilities. The
municipality reserves the right to accept or reject the operations
and maintenance responsibility for any or all of the stormwater controls
and BMPs.
A.
The municipality shall review the stormwater control
and BMP operations and maintenance plan for consistency with the purposes
and requirements of this article and any permits issued by DEP.
B.
The municipality shall notify the applicant in writing
whether or not the stormwater control and BMP operations and maintenance
plan is approved.
C.
The municipality may require a "record drawing" of
all stormwater controls and BMPs and an explanation of any discrepancies
with the operations and maintenance plan.
It shall be unlawful to alter or remove any
permanent stormwater control and BMP required by an approved stormwater
control and BMP operations and maintenance plan or to allow the property
to remain in a condition which does not conform to an approved stormwater
control and BMP operations and maintenance plan.
A.
The applicant shall sign an operations and maintenance
agreement with Haverford Township covering all stormwater controls
and BMPs that are to be privately owned. The maintenance agreement
shall be transferred with transfer of ownership. The agreement shall
be substantially the same as the agreement in Appendix I of this article.[1]
[1]
Editor's Note: Appendix I, the Operation and Maintenance Agreement for BMPs, is included at the end of this chapter.
B.
Other items may be included in the agreement where
determined necessary to guarantee the satisfactory operation and maintenance
of all permanent stormwater controls and BMPs. The agreement shall
be subject to the review and approval of Haverford Township.
A.
Stormwater management easements are required for all
areas used for off-site stormwater control, unless a waiver is granted
by the municipal Engineer.
B.
Stormwater management easements shall be provided by the applicant or property owner if necessary for access for inspections and maintenance or the preservation of stormwater runoff conveyance, infiltration, and detention areas and other stormwater controls and BMPs by persons other than the property owner. The purpose of the easement shall be specified in any agreement under § 78-47.
A.
Prior to final approval of the site's drainage plan,
the applicant shall sign and record the maintenance agreement contained
in Appendix I,[1] which is attached and made part hereof, covering all stormwater
control facilities that are to be privately owned.
[1]
Editor's Note: Appendix I, the Operation and Maintenance Agreement for BMPs, is included at the end of this chapter.
B.
Other items may be included in the agreement where
determined necessary to guarantee the satisfactory maintenance of
all facilities. The maintenance agreement shall be subject to the
review and approval of the municipal Solicitor and Board of Commissioners.
A.
The owner of any land upon which permanent stormwater
controls and BMPs will be placed, constructed, or implemented, as
described in the stormwater control and BMP operations and maintenance
plan, shall record the following documents in the Office of the Recorder
of Deeds for Delaware County within 15 days of approval of the stormwater
control and BMP operations and maintenance plan by the municipality:
B.
The municipality may suspend or revoke any approvals
granted for the project site upon discovery of failure on the part
of the owner to comply with this section.
A.
Persons installing stormwater controls or BMPs shall
be required to pay a specified amount to the Municipal Stormwater
Control and BMP Operation and 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 control or BMP is to be privately
owned and maintained, the deposit shall cover the cost of periodic
inspections performed by Haverford Township 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 control or BMP is to be owned and
maintained by Haverford Township, the deposit shall cover the estimated
costs for maintenance and inspections for 10 years. The municipal
Engineer will establish the estimated costs utilizing information
submitted by the applicant.
(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.
B.
If a stormwater control or BMP is proposed that also
serves as a recreational facility (e.g., ball field or lake), Haverford
Township may reduce or waive the amount of the maintenance fund deposit
based upon the value of the land for public recreational purpose.
C.
If at some future time a stormwater control or BMP
(whether publicly or privately owned) is eliminated due to the installation
of storm sewers or other storage facility, the unused portion of the
maintenance fund deposit will be applied to the cost of abandoning
the facility and connecting to the storm sewer system or other facility.
Any amount of the deposit remaining after the costs of abandonment
are paid will be returned to the depositor.
D.
If stormwater controls or BMPs are accepted by Haverford
Township for dedication, the municipality may require persons installing
stormwater controls or BMPs to pay a specified amount to the Municipal
Stormwater Control and BMP Operation and Maintenance Fund to help
defray costs of operations and maintenance activities. The amount
may be determined as follows:
E.
If a stormwater control or BMP is proposed that also
serves as a recreational facility (e.g., ball field or lake), Haverford
Township may adjust the amount due accordingly.
F.
Haverford Township shall require applicants to pay
a fee to the Municipal Stormwater Control and BMP Operation and Maintenance
Fund to cover long-term maintenance of stormwater controls and BMPs.
G.
Haverford Township may require applicants to pay a
fee to the Municipal Stormwater Control and BMP Operation and Maintenance
Fund to cover stormwater-related problems which may arise from the
land development and earth disturbance.
A.
No person in Haverford Township shall allow, or cause to allow, stormwater discharges into the municipality's separate storm sewer system which are not composed entirely of stormwater, except 1) as provided in Subsection B below; and 2) discharges allowed under a state or federal permit.
B.
Discharges that may be allowed based on a finding
by the municipality that the discharge(s) do not significantly contribute
to pollution to surface waters of the commonwealth, are:
(1)
Discharges from fire-fighting activities.
(2)
Potable water sources including dechlorinated waterline
and fire hydrant flushings.
(3)
Irrigation drainage.
(4)
Routine external building washdown (which does not
use detergents or other compounds).
(5)
Air conditioning condensate.
(6)
Water from individual residential car washing.
(7)
Spring water from crawl space pumps.
(8)
Uncontaminated water from foundation or from footing
drains.
(9)
Flows from riparian habitats and wetlands.
(10)
Lawn watering.
(11)
Pavement washwaters where spills or leaks of
toxic or hazardous materials have not occurred (unless all spill material
has been removed) and where detergents are not used.
(12)
Dechlorinated swimming pool discharges.
(13)
Uncontaminated groundwater.
C.
In the event that the municipality 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, Haverford Township will notify the responsible person to cease the discharge.
D.
Upon notice provided by the municipality under Subsection C, the discharger will have a reasonable time, as determined by Haverford 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.
[1]
Editor's Note: The following language taken
from DEP's NPDES program and model NPDES ordinance is required to
be incorporated into this article.
The following connections are prohibited, except as provided in § 78-52B above:
A.
Any drain or conveyance, whether on the surface or
subsurface, which allows any non-stormwater 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 Haverford Township.
A.
Roof drains shall not be connected to streets, sanitary
or storm sewers, or roadside ditches in order to promote overland
flow and infiltration/percolation of stormwater where advantageous
to do so.
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 on a case-by-case basis as determined
by Haverford Township.
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 control or BMP unless it is part of
an approved maintenance program without the written approval of the
municipality.
B.
No person shall place any structure, fill, landscaping,
or vegetation into a stormwater control or BMP or within a drainage
easement which would limit or alter the functioning of the stormwater
control or BMP without the written approval of Haverford Township.
A.
Upon presentation of proper credentials, duly authorized
representatives of the municipality may enter at reasonable times
upon any property within Haverford Township to inspect the implementation,
condition, or operation and maintenance of the stormwater controls
or BMPs in regard to any aspect governed by this article.
B.
Stormwater control and BMP owners and operators shall
allow persons working on behalf of Haverford Township ready access
to all parts of the premises for the purposes of determining compliance
with this article.
C.
Persons working on behalf of Haverford Township shall
have the right to temporarily locate on any stormwater control or
BMP in the municipality such devices as are necessary to conduct monitoring
and/or sampling of the discharges from such stormwater control or
BMP.
D.
Unreasonable delays in allowing the municipality access
to a stormwater control or BMP is a violation of this article.
A.
Whenever Haverford Township finds that a person has
violated a prohibition or failed to meet a requirement of this article,
the municipality may order compliance by written notice to the responsible
person. Such notice may, without limitation, require the following
remedies:
(1)
Performance of monitoring, analyses, and reporting;
(2)
Elimination of prohibited connections or discharges;
(3)
Cessation of any violating discharges, practices,
or operations;
(4)
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)
Implementation of stormwater controls and BMPs; and
(7)
Operation and maintenance of stormwater controls and
BMPs.
B.
Such notification shall set forth the nature of the
violation(s) and establish a time limit for correction of these violations(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 Haverford Township or designee, and the expense
thereof shall be charged to the violator.
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 municipality from pursuing any and all other remedies available
in law or equity.
A.
Any building, land development, or other permit or
approval issued by Haverford Township may be suspended or revoked
by the municipality 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, health,
or property of others.
B.
A suspended permit or approval shall be reinstated
by the municipality when:
C.
A permit or approval that has been revoked by the
Township cannot be reinstated. The applicant may apply for a new permit
under the procedures outlined in this article.
A.
Any person violating the provisions of this article
shall be guilty of a misdemeanor and upon conviction shall be subject
to a fine of not more than $1,000 for each violation, recoverable
with costs, or imprisonment of not more than 90 days, or both. Each
day that the violation continues shall be a separate offense.
[Amended 3-12-2012 by Ord. No. 2660]
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.
In the event that a person fails to comply with
the requirements of this article or fails to conform to the requirements
of any permit issued hereunder, the Township shall provide written
notification of the violation. Such notification shall state the nature
of the violation(s) and establish a time limit for correction of these
violation(s). Failure to comply within the time specified shall 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 remedies. It shall be the responsibility of the
owner of the real property on which any regulated activity is proposed
to occur, is occurring, or has occurred to comply with the terms and
conditions of this article.
The Board of Commissioners is hereby authorized
and directed to enforce all of the provisions of this article. All
inspections regarding compliance with the drainage plan shall be the
responsibility of the Township Engineer or other qualified persons
designated by the Board of Commissioners.
A.
A set of design plans approved by the Township shall
be on file at the site throughout the duration of the construction
activity. Periodic inspections may be made by the Township or designee
during construction.
B.
It shall be unlawful for any person, firm, or corporation to undertake any regulated activity under § 78-16 on any property except as provided for in the approved drainage plan and pursuant to the requirements of this article. It shall be unlawful to alter or remove any control structure required by the drainage plan pursuant to this article or to allow the property to remain in a condition which does not conform to the approved drainage plan.
C.
At the completion of the project and as a prerequisite
for the release of the performance guarantee, the owner or his representatives
shall:
D.
After receipt of the certification by Haverford Township,
a final inspection shall be conducted by the municipal Engineer or
designated representative to certify compliance with this article.
E.
Prior to revocation or suspension of a permit and
at the request of the applicant, the governing body will schedule
a hearing to discuss the noncompliance if there is no immediate danger
to life, public health, or property. The expense of a hearing shall
be the applicant's responsibility.
A.
Any person aggrieved by any action of the municipality
or its designee may appeal to the Board of Commissioners of Haverford
Township within 30 days of that action.
B.
Any person aggrieved by any decision of the Board
of Commissioners of Haverford Township may appeal to the County Court
of Common Pleas in the County where the activity has taken place within
30 days of the municipal decision.
