[HISTORY: Adopted by the Board of Supervisors of the Township
of Carroll 11-8-2007 by Ord. No. 2007-4. Amendments noted where applicable.]
This chapter is adopted and implemented to achieve the following
general purposes and objectives:
A.
To manage stormwater runoff resulting from land alteration and disturbance
activities in accordance with the Carroll Township Stormwater Management
Plan as adopted by the Carroll Township Board of Supervisors.
B.
To utilize and preserve the desirable existing natural drainage systems,
preserve the flood-carrying capacity of existing streams, and preserve
existing storm event water surface elevations in existing streams.
C.
To encourage natural infiltration of rainfall to preserve groundwater
supplies and stream flows.
D.
To provide for adequate maintenance of all permanent stormwater management
facilities 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.
The Act of October 4, 1978, P.L. 864 (Act 167), 32 P.S. § 680.1
et seq., as amended, the Storm Water Management Act (hereinafter referred
to as "the Act");
B.
The Water Resources Management Act of 2002, as amended;
C.
The Second Class Township Code, 53 P.S. § 65101 et seq., and
the Borough Code, 53 P.S. § 45101 et seq.; and
The provisions of this chapter shall apply to all subdivision
and land developments unless specifically exempted or otherwise modified
herein.
The following activities are defined as regulated activities and shall be regulated by this chapter unless exempted by § 216-6:
A.
Land development.
B.
Subdivisions.
C.
Alteration of the natural hydrologic regime.
D.
Construction or reconstruction of or addition of new impervious or
semipervious surfaces (i.e., driveways, parking lots, roads, etc.).
E.
Construction of new buildings or additions to existing buildings.
F.
Redevelopment.
G.
Diversion piping or encroachments in any natural or man-made channel.
H.
Nonstructural and structural stormwater management BMPs or appurtenances
thereto.
I.
Earth disturbance activities of greater than 5,000 square feet. (NOTE
1: This chapter 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 and associated
stormwater management controls are also regulated under existing state
law and implementing regulations. This chapter shall operate in coordination
with those parallel requirements; the requirements of this chapter
shall be no less restrictive in meeting the purposes of this chapter
than state law. Table 102.1 summarizes the applicability requirements
of the ordinance.[1] "Proposed impervious surface" in Table 102.1 includes
new, additional or replacement impervious surface/cover. Repaving
existing surfaces without reconstruction does not constitute "replacement.")
[1]
Editor's Note: Table 102.1 is attached to this chapter.
J.
Any of the above regulated activities which were approved more than
five years prior to the effective date of this chapter and resubmitted
for municipal approval.
For the purposes of this chapter, the following terms shall
be defined as follows:
A landowner or developer, as defined by this chapter, who
has filed an application for development, including his/her heirs,
successors and assigns.
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 practice (BMP)."
A natural stream that conveys water, a ditch or open channel
excavated for the flow of water.
The Washington County Conservation District.
The magnitude of precipitation from a storm event measured
in probability of occurrence (e.g., twenty-five-year storm) and duration
(e.g., twenty-four-hour), and used in computing stormwater management
control systems.
The slowing, dampening or attenuation of runoff entering
the natural drainage pattern or storm drainage system by temporarily
holding water in a detention basin, retention basin, reservoir on
rooftops, in streets, parking lots, or within the drainage system
itself, and releasing the water at a desired rate of discharge.
A facility designed to attenuate peak stormwater runoff by
storing and releasing the runoff at a predetermined rate. A detention
facility is designed to drain completely after a rainfall event. The
facility shall not hold any water for longer than 24 hours after the
peak discharge from the facility occurs.
Any landowner, agent of such landowner, or tenant with permission
of such landowner, who makes or causes to be made a subdivision of
land or land development.
Any activity, construction, alteration, or change in land
use, or similar action, that affects stormwater runoff characteristics.
A lot, parcel or tract of land on which development is taking
place or is proposed.
Rate of flow, specifically, fluid flow. A volume of fluid
flowing from a conduit or channel or being released from detention
storage, per unit of time, commonly expressed as cubic feet per second
(cfs), million gallons per day (mgd), gallons per minute (gpm), or
cubic meters per second (cms).
Interception and removal of excess surface water or groundwater
from land by artificial or natural means.
The contributing area to a single drainage basin, expressed
in acres, square miles, or other units of area; also called a catchment
area, watershed or river basin; the area served by a drainage system
or by a watercourse receiving stormwater and surface water.
The area from which water is carried off by the drainage
system; a watershed or catchment area.
A right granted by a landowner to a grantee allowing the
use of private land for stormwater management purposes.
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 antidegradation).
A normally dry land area adjacent to stream channels that
is susceptible to being inundated by overbank stream flows. For regulatory
purposes, the Pennsylvania Flood Plain Management Act (Act of October
4, 1978, P.L. 851, No. 166)[1] and regulations pursuant to the Act define the floodplain
as the area inundated by a one-hundred-year flood and delineated on
a map by FEMA (Federal Emergency Management Agency) or by the applicant
in accordance with municipal ordinance requirements.
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.
Measurement from a water surface elevation to the top of
a hydraulic structure. (e.g., detention/retention basin, inlets, manholes,
etc.).
Computer model developed by the Army Corps of Engineers to
predict flood hydrographs.
Computer model developed by the Army Corps of Engineers to
perform one-dimensional hydraulic calculations for a full network
of natural and constructed channels.
Surface waters having a level of 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).
The branch of science concerned with the mechanics of fluids,
especially liquids. As applied in stormwater management, the study
of the characteristics of water flow in, and conveyance capacity of,
a channel, conduit or watercourse, considering such factors as depth,
velocity and turbulence.
The science dealing with waters of the earth and their distribution
and circulation through the atmosphere. Engineering hydrology deals
with the application of hydrologic concepts to determine volume and
rate of runoff.
Material which resists the entrance of water or other liquids.
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.
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 Section 503(1.1) of the Pennsylvania
Municipalities Planning Code.[2]
Any activity involving grading, tilling, digging or filling
or stripping of vegetation; or any other activity which causes land
to be exposed to the danger of erosion or changed water flow characteristics.
The legal or beneficial owner or owners of land, including
the holder of an option or contract to purchase (whether or not such
option or contract is subject to any condition), a lessee if he/she
is authorized under a lease agreement to exercise the rights of the
landowner, or other persons having a proprietary interest in land.
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.
Natural Resources Conservation Service, United States Department
of Agriculture; formerly the SCS, Soil Conservation Service. [3]
Points or areas at which stormwater runoff leaves a structure
or site, which may include streams, storm sewers, swales or other
well-defined natural or artificial drainage features, as well as areas
of dispersed overland flows.
A structure designed to control the volume of stormwater
runoff that passes through it during a specific length of time.
Pennsylvania Department of Environmental Protection.
The maximum flow of water at a given point and time resulting
from a predetermined storm.
A standard which establishes an end result or outcome which
is to be achieved but does not prescribe specific means for achieving
it. A "specification standard," in contrast, is one which prescribes
the exact characteristics to be used, leaving little choice to the
applicant. The release rate percentage is an example of a performance
standard; the design standards for storm sewers are specification
standards.
Material which permits the entrance of water or other liquid.
A point of hydraulic concern such as a bridge, culvert or
channel section, for which the rate of runoff is computed or measured,
and usually located at the downstream limits of a subarea.
Instantaneous measurement of water flow expressed in a unit
of volume per unit of time, also referred to as "discharge," usually
stated in cubic feet per second (cfs) or gallons per minute (gpm).
Defined under NPDES Phase II regulations as earth disturbance
activity of one acre or more with a point source discharge to surface
waters or the 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 predevelopment peak rate of runoff from
a watershed subarea (as delineated in a watershed plan) which defines
the allowable post development peak discharge from any development
site in that subarea. The release rate percentage is determined by
computing the following ratio:
|
Subarea post-development peak rate of runoff
Subarea predevelopment peak rate of runoff
|
x 100 = Release Rate Percentage
|
A facility designed to attenuate peak stormwater runoff while
maintaining a permanent pool of water and releasing the remaining
runoff at a predetermined rate.
The surface components of any watershed which affect the
rate, amount and direction of stormwater runoff. These may include
but are not limited to vegetation, soils, slopes and man-made landscape
alterations.
Solid material, both mineral and organic, that is in suspension,
is being transported, or has been moved from its site or origin by
air, water, gravity or ice and has come to rest on the earth's
surface.
Any subdivision, land development, or development which results,
or will result when fully constructed, in the creation of an aggregate
total of 10,000 square feet or less of additional impervious surface
area from the date of this chapter.
A method or runoff computation developed by the United States
Soil Conservation Service (now the Natural Resources Conservation
Service) and found in its publication "Urban Hydrology for Small Watersheds,"
Technical Release No. 55, SCS, January 1975 (or most current edition).
As defined under state regulations — protection of
designated and existing uses (see 25 Pa. Code Chapters 93 and 96),
including:
Each stream segment in Pennsylvania has a designated use, such
as cold water fishery or potable water supply, which is listed in
Chapter 93. These uses must be protected and maintained under state
regulations.
Existing uses are those attained as of November 1975, regardless
of whether they have been designated in Chapter 93. Regulated earth
disturbance activities must be designed to protect and maintain existing
uses and maintain the level of water quality necessary to protect
those uses in all streams and to protect and maintain water quality
in special protection streams.
Water quality involves the chemical, biological and physical
characteristics of surface water bodies. After regulated earth disturbance
activities are complete, these characteristics can be impacted by
the addition of pollutants such as sediment and changes in habitat
through increased flow volumes and/or rates as a result of changes
in land surface area from those activities. Therefore, permanent discharges
to surface waters must be managed to protect the stream bank, streambed,
and structural integrity of the waterway to prevent these impacts.
(See "detention basin" or "retention basin.")
An underground conduit that carries intercepted surface runoff,
street water, and other drainage, but excludes domestic sewage and
industrial wastes.
Natural or engineered structures which collect and transport
stormwater through or from a drainage area to the point of final outlet,
including, but not limited to, any of the following: conduits and
appurtenant features, basins, canals, channels, ditches, streams,
culverts, streets and pumping stations.
An area whose boundaries are contiguous with those of the
watersheds located in Carroll Township.
The plan for managing stormwater runoff from a specific development
site prepared by a professional engineer registered to practice in
Pennsylvania.
Waters resulting from snowmelt or precipitation within a
drainage basin, flowing over the surface of the ground, collected
in channels and conduits, and carried by receiving streams.
A watercourse.
A portion of the watershed that has similar hydrological
characteristics and drains to a common point of interest.
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 which gathers or carries surface
water runoff.
The plan for managing stormwater.
Quantity of water normally measured in inches, cubic feet,
or acre-feet, measured or determined analytically from: 1) runoff
coefficients; 2) rainfall/runoff ratios; and 3) areas underneath hydrographs.
Any channel of conveyance of surface water having a defined
bed and banks, whether natural or artificial, with perennial or intermittent
flow.
The entire region or area drained by a river or other body
of water, whether natural or artificial. A "designated watershed"
is an area delineated by PADEP and approved by the Environmental Quality
Board as one for which the County is required to prepare a watershed
stormwater management plan in accordance with the Pennsylvania Storm
Water Management Act.[4]
Those areas that are inundated or saturated by surface water
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 diameter at breast height (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.
A.
Applicants proposing regulated activities in the Township which do not fall under the exemption criteria shown in § 216-9 shall submit a stormwater management plan consistent with this chapter to the Township for review. The stormwater management criteria of this chapter shall apply to all portions of the entire 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 stormwater management plan must be designed consistent with the sequencing provisions of § 216-10 to ensure maintenance of the natural hydrologic regime, to promote groundwater recharge, and to protect groundwater and surface water quality and quantity. The stormwater management plan designer must proceed sequentially in accordance with § 216-10 of this chapter.
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 chapter.
E.
Existing points of concentrated drainage that discharge onto adjacent
property shall not be altered in any manner which could cause property
damage and will not be incorporated in the plans without permission
of the affected property owner(s) and shall be subject to any applicable
discharge criteria specified in this chapter.
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 chapter.
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 § 216-16B(7) of this chapter.
H.
Any stormwater management facilities regulated by this chapter 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 chapter
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 water or groundwater.
L.
All regulated activities within the Township shall be designed, implemented,
operated and maintained to meet the purposes of this chapter through
these two elements:
M.
No regulated earth disturbance activities within the Township shall
commence until the requirements of this chapter are met.
N.
Post-construction water quality protection shall be addressed as required by § 216-20, Water quality requirements and stormwater best management practices.
O.
Operations and maintenance of permanent stormwater BMPs shall be addressed as required by § 216-26, Responsibilities for operations and maintenance of stormwater controls and BMPs.
P.
All BMPs used to meet the requirements of this chapter shall conform
to the state water quality requirements and any more stringent requirements
as set forth by the Township.
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.
A permit to construct the stormwater facilities as approved by the
Township Supervisors.
B.
All regulated earth disturbance activities subject to permit requirements
by DEP under regulations at 25 Pa. Code Chapter 102.
C.
Work within natural drainageways subject to permit by DEP under 25
Pa. Code Chapter 105.
D.
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 Pa. Code Chapter 105.
E.
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. In the case where a driveway entrance
is required from a state road to access stormwater facilities, a highway
occupancy permit and any further approval required by the PennDOT
will be applied for and obtained by the applicant for the development.
F.
Culverts, bridges, storm sewers, or any other facilities which must
pass or convey flows from the tributary area and any facility which
may constitute a dam subject to permit by DEP under 25 Pa. Code Chapter
105.
A.
No regulated earth disturbance activities within the Township shall
commence until the 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 Pa. Code § 102.4(b).
C.
D.
Evidence of any necessary permit(s) for regulated earth disturbance
activities from the appropriate DEP regional office or county conservation
district must be provided to the Township. The issuance of an NPDES
construction permit [or permit coverage under the statewide general
permit (PAG-2)] satisfies the requirements of this subsection.
E.
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.
F.
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. Additional measures, such as placement of orange construction
fencing around proposed infiltration BMPs during construction to minimize
or eliminate traffic over top these areas and temporary sealing off
of pipes and inlet connections to infiltration BMPs to prevent sediment
clogging, should be done.
(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.
General requirements. No final subdivision or land development plan
shall be approved, no permit authorizing construction issued, or any
earthmoving or land disturbance activity initiated until the final
stormwater management plan for the development site is approved in
accordance with the provisions of this chapter.
(1)
The following items shall be included in the stormwater management
plan or drainage plan (small development):
(b)
General description of proposed permanent stormwater management
techniques, including construction and materials specifications of
the materials to be used for stormwater management facilities.
(c)
USGS map at scale of one inch equals 2,000 feet with the project
area outlined.
(d)
An erosion and sediment control plan, including all reviews
and letters of adequacy from the conservation district.
(2)
The following items shall be included in the stormwater management
plan for large and small land disturbances, subdivisions or land developments:
(b)
General description of proposed permanent stormwater management
techniques, including construction specifications of the materials
to be used for stormwater management facilities.
(c)
Complete hydrologic, hydraulic, and structural computations
for all stormwater management facilities.
(d)
An erosion and sediment control plan, including all reviews
and letters of adequacy from the conservation district.
(3)
Proof of application or documentation of required permit(s) or approvals
for the programs listed below:
(4)
For any of the activities regulated by this chapter, 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 stormwater management plan from the Township, obtained an NPDES
permit for stormwater discharges associated with construction activities
if greater than one acre of land disturbance from the local conservation
district and/or PADEP, and an adequate erosion and sediment control
plan review by the conservation district.
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 Washington County. 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. In areas of slopes greater
than 25%, five-foot contour intervals may be used.
(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 drainagecourses, 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,
water wells, and waterlines within the project area and within 50
feet of outer property lines.
(6)
An overlay showing soil names, boundaries and limitations (in tabular
format).
(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)
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.
(10)
The date of submission.
(11)
Location of all open channels, as well as indicating where they
are draining after they leave the site (storm sewer, defined drainage
swale, stream channel, waters of the commonwealth, etc.).
(12)
The location of all erosion and sediment control facilities
and all post-construction stormwater management facilities, BMPs,
systems, etc.
(13)
A statement, signed by the applicant, acknowledging that any
revision to the approved post-construction stormwater management plan
must be approved by the Township and the conservation district and/or
PADEP (if greater than one acre of land disturbance), and that a revised
erosion and sediment control plan must be submitted to the conservation
district for a determination of adequacy.
C.
Supplemental information to be submitted to the Township.
(1)
A written description of the following information shall be submitted
by the applicant and shall include:
(a)
The overall stormwater management concept for the project designed.
(b)
Stormwater runoff computations as specified in this chapter.
(c)
Stormwater management techniques to be applied both during and
after development.
(d)
Expected project time schedule.
(e)
Development stages or project phases, if so proposed.
(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 post-construction stormwater management (PCSWM) BMPs facilities
must be located on a plan and described in detail. The PCSWM plan
package should include at a minimum preconstruction and post-construction
drainage area plans, an overall PCSWM plan, PCSWM details sheets,
landscaping or conservation plans, etc.
(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. Minimum setback distances should be
identified from water supply wells, septic areas, and any adjacent
or downgradient buildings and/or structures with below-grade floors
or inhabitable space.
(3)
All calculations, assumptions, and criteria used in the design of
the stormwater management facilities must be shown.
(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.
E.
Exemptions for small developments.
(1)
At the time of application, the Township shall determine if the subdivision
or land development qualifies as a "small development" and, therefore,
is eligible for a simplified stormwater management plan submission.
For the purposes of this chapter, a small development is any subdivision
or land development which results (or will result when fully constructed)
in the creation of a total aggregate of 10,000 or less square feet
of impervious surface area. For small developments which result in
the addition of a total aggregate of less than 5,000 square feet of
impervious area, no stormwater management is required. However, such
developments must still provide safe conveyance of the stormwater
to a storm sewer or a natural or man-made waterway.
(2)
Small developments shall be exempt from the preparation of a stormwater management plan as specified by §§ 216-7 and 216-8 of this chapter. However, such developments must still provide safe management of stormwater runoff with the methods to be approved by the Township Engineer. Any stormwater management facility constructed as part of the development shall be designed to control the peak stormwater runoff for the two-, ten-, twenty-five- and one-hundred-year design storms. For small developments which result in the addition of 5,000 square feet but less than 10,000 square feet of impervious surface area, stormwater management shall be provided. However, the small development will be exempt from the preparation of a stormwater management report by a professional engineer, but must submit a drainage plan under the requirements of Subsection E(3). On-lot storage may be used in the form of underground tanks.
(3)
Applications for all small developments (5,000 to 10,000 square feet
of impervious surface) shall include a drainage plan which describes,
narratively and graphically, the type and location of proposed on-site
stormwater management techniques or the proposed connection to an
existing storm sewer system. The plan should show, accurately, site
boundaries; contours at five-foot intervals for areas of greater than
fifteen-percent slope gradient and at two-foot intervals for areas
with less than 15% slope; location of watershed and/or subarea boundaries
on the site (if applicable); lot lines and surrounding owners' names
on all sides; and any watercourses, floodplains or existing drainage
facilities or structures located on the site.
(4)
The Township Engineer shall review and approve the proposed provisions
for stormwater management for a small development. Where the applicant
is proposing to connect to an existing storm sewer, the applicant
shall demonstrate that sufficient capacity exists in the storm sewer
from the point of connection to the point of outlet in the natural
drainage system. The Township Engineer shall determine if the proposed
development site is part of a larger parcel or tract for which a stormwater
management plan was approved previously and, therefore, subject to
any specific stormwater management control contained in the prior
plan.
(5)
For a parcel or tract of land held under single ownership, only one
application for a small development, as defined above, shall be permitted
before requiring a stormwater management plan for the entire parcel.
F.
Additional exemption criteria.
(1)
Exemption responsibilities. An exemption shall not relieve the applicant
from implementing such measures as are necessary to protect public
health, safety and property.
(2)
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 (§ 216-10, Nonstructural project design).
(3)
Drainage problems. If a drainage problem is documented or known to
exist downstream of or is expected from the proposed activity, then
the Township may require the applicant to comply with this chapter.
(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 within two calendar days of the commencement of the
activity. If the Township finds that the work is not an emergency,
then the work shall cease immediately, and the requirements of this
chapter 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 Township.
(6)
Even though the developer is exempt, he is not relieved from complying
with other regulations.
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, 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.
(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, hydrologic soil groups, wooded areas, and potential
infiltration areas. Land development, any existing recharge areas,
and other requirements outlined in the municipal comprehensive plan
shall also be included.
(2)
Establish a stream buffer according to § 216-16B(7).
(3)
Prepare a draft project layout avoiding sensitive areas identified in § 216-10B(1).
(4)
Identify site-specific existing conditions drainage areas, discharge
points, recharge areas, and hydrologic soil groups A and B (areas
conducive to infiltration). Infiltration should still be considered
in well-draining soils listed as hydrologic soil group C, but additional
soils testing should be performed to verify on-site conditions and
placement of these BMPs.
(7)
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.
(8)
Conduct a proposed conditions runoff analysis based on the final design that meets the management district requirements [§ 216-16C(3)].
(9)
Manage any remaining runoff prior to discharge through detention,
bioretention, direct discharge, or other structural control.
A.
General format. The stormwater management plan shall be prepared
using the following requirements:
(1)
Watershed mapping. For the design of the site stormwater management
facilities, provide clear mapping that delineates the watershed boundaries
for the proposed development site for existing and post-construction
conditions. Clearly illustrate the time of concentration paths for
both existing and post-construction conditions. Watershed mapping
shall also be provided for the design of storm sewer inlets.
(2)
Floodplain boundaries. Identify one-hundred-year floodplains on the
development site (as appropriate) from the Township's Flood-Prone
Area Map or the applicant's determination of the one-hundred-year
floodplain for any watercourse or water body on the development site
with a drainage area of 100 acres or more.
(3)
Natural features. Show all bodies of water (natural and artificial),
watercourses (permanent and intermittent), swales, wetlands and other
natural drainagecourses on the development site or which will be affected
by runoff from the development.
(4)
Soils. Provide an overlay showing soils types and boundaries within
development site (consult County, NRCS, United States Geologic Survey
for information).
(5)
Contours. Show existing and final contours at intervals of two feet;
in areas with slopes greater than 15%, five-foot contour intervals
may be used.
(6)
Stormwater management controls. Show any existing stormwater management
or drainage controls and/or structures, such as storm sewers, swales,
culverts, etc., which are located on the development site or which
are located off site but will be affected by runoff from the development.
B.
Professional certification. The stormwater management plan, including
all calculations, must be prepared and sealed by a registered professional
engineer qualified to make certification under the laws of Pennsylvania.
C.
Runoff calculations. Calculations for determining predevelopment and post-development discharge rates and for designing proposed stormwater control facilities must be submitted with the stormwater management plan. All calculations shall be prepared using the method and data prescribed by § 216-16.
D.
Stormwater controls. All proposed stormwater runoff control measures
must be shown on the plan, including methods for collecting, conveying
and storing stormwater runoff on site which are to be used both during
and after construction. Erosion/sedimentation controls must be shown.
The preliminary plan must provide information on the general type,
location, sizing, etc., of all proposed facilities and their relationship
to the existing watershed drainage system.
E.
Easements, rights-of-way, deed restrictions. All existing and proposed
easements and rights-of-way for drainage and/or access to stormwater
control facilities shall be shown and the proposed owner identified.
Show any areas subject to special deed restrictions relative to or
affecting stormwater management on the development site.
F.
Other permits/approvals. A list of any approvals/permits relative
to stormwater management that will be required from other governmental
agencies, e.g., a water obstruction permit from PADEP. Anticipated
dates of submission/receipt should be included with the preliminary
plan submission. The Township may request copies of the applications
if they may be helpful for the stormwater plan review.
G.
Maintenance program. The preliminary application shall contain a
proposed maintenance plan for all stormwater control facilities, in
accordance with the following:
(1)
Identify the proposed ownership entity (e.g., municipality, property
owner, a homeowners' association, other management entity).
(2)
If ownership is to be an entity other than the Township, include a maintenance program for all facilities, outlining the type of maintenance activities, probable frequencies, personnel and equipment requirements, and estimated annual maintenance costs. See also § 216-13B(4).
(3)
Identify method of financing the continuing operation and maintenance
if facility is to be owned by other than the Township or other governmental
agency.
A.
All information pertaining to stormwater management from the preliminary
plan along with any changes.
B.
Final maps showing the exact nature and location of all temporary
and permanent stormwater management controls under the design and
construction specifications.
C.
A schedule for the installation of all temporary and permanent stormwater
control measures and devices.
D.
An accurate survey showing all current and proposed easements and
rights-of-way and copies of all proposed deed restrictions.
E.
A maintenance program establishing ownership and maintenance responsibilities for all stormwater control facilities (identify specific person or entity) and detailing financial requirements and sources of funding. Submit any legal agreements required to implement the maintenance program and copies of the maintenance agreement as specified by § 225-48 of the Subdivision and Land Development Ordinance.
F.
Financial guarantees, to ensure that all stormwater controls are
installed properly and functioning satisfactorily.
G.
Performance guarantee. The applicant shall provide a financial guarantee
to Carroll Township for the timely installation and proper construction
of all stormwater management controls as required by the approved
stormwater plan and this chapter.
A.
Preapplication phase.
(1)
During the preapplication conference, applicants are urged to consult
with the Township and the Washington County Planning Department on
the requirements for safely managing stormwater runoff from the development
site in a manner consistent with the Township ordinances and the Township
Stormwater Management Plan. These agencies may be helpful in providing
the data that is necessary for preparing the stormwater management
plan for the development site.
(2)
Applicants are encouraged to submit a sketch plan with a narrative
description of the proposed stormwater management controls and general
hydrologic parameters for general guidance and discussion with Township
and county agencies.
(3)
The preapplication phase is not mandatory, and any review comments
provided by Township or county agencies are advisory only and do not
constitute any legally binding action on the part of the Township
or any county agency.
B.
Preliminary and final stormwater plan reviews.
(1)
Preliminary and final plans required. Stormwater management plans, in accordance with the requirements of § 216-6, will be submitted with the preliminary and final subdivision or land development plan application. The maximum impervious surface area that may be placed on individual lots must be shown on the construction plan as well as the recorded plan. The square foot area shall be shown on the plans in the form of a table.
(2)
Review by Township Engineer. Preliminary and final stormwater management
plans will be reviewed by the Township Engineer if over three acres.
At its discretion, the Township may also engage other specialists
in hydrology or hydraulics to assist with the stormwater plan review.
(3)
Notification of affected municipalities. If during the review of
the proposed stormwater management plan, the Township determines that
properties in adjacent municipalities may be affected by the stormwater
runoff and proposed management system for the site, it will notify
the affected municipality(ies) and provide an opportunity to submit
comments as part of the preliminary or final plan reviews. Copies
of the plans will be made available to the municipalities upon request.
Comments received will be submitted to the Planning Commission and
the Township Board of Supervisors.
(4)
Township Engineer's review. The Township Engineer shall approve
or disapprove the preliminary and final stormwater management plan
based on the requirements of the Township's ordinances, the standards
and criteria of the Township Stormwater Management Plan, and good
engineering practice. The developer shall submit a written report,
along with supporting documentation, to the Township Planning Commission
for its consideration as part of the overall subdivision or land development
plan review. In the case that the Township will be responsible for
the maintenance of the stormwater management facility, the developer's
design engineer shall submit tabled recommended maintenance inspections
in accordance with the guidelines in Appendix I[1] and PennDOT approvals in accordance with § 216-8E for review and approval by the Board of Supervisors.[2]
(5)
Status of the Engineer's determination. The approval/disapproval
of the site's stormwater management plan by the Township Engineer
shall be considered final. The Planning Commission (or Board of Supervisors)
can request modifications or alternative approaches to the stormwater
management controls consistent with the low-impact provisions of the
best management practices, provided these are agreed to by the Township
Engineer and the applicant's engineer who must certify the plans.
(6)
Approval of stormwater plan required for subdivision/land development
approval. No preliminary or final approval shall be granted for the
overall subdivision or land development application until a stormwater
management plan for the site has been approved.
(7)
Permits required from other governmental agencies. When the subdivision
or land development application requires permits from the Pennsylvania
Department of Environmental Protection, United States Army Corps of
Engineers, or other regulatory agency, then final subdivision or land
development plan approval shall be conditional upon receipt of such
permits. However, no building permit shall be issued or construction
started, until the permits are received and copies filed with the
Township.
Upon providing adequate financial guarantees, as outlined in Chapter 225, Subdivision and Land Development, and after the Township has issued a permit and the notice to proceed, the applicant may commence to install or implement the approved stormwater management controls, subject to the provisions of § 216-13B(6) as above. If site development or building construction does not begin within two years of the date of the final approval of the subdivision or land development plan, then before doing so the applicant shall resubmit the stormwater management plans to verify that no condition has changed within the watershed that would affect the feasibility or effectiveness of the previously approved stormwater management controls. Further, if for any reason development activities are suspended for two years or more, then the same requirement for resubmission of the stormwater management plan shall apply.
Procedures for approving plan modifications. Requests for modification
in the final approved stormwater management controls shall be submitted
to the Township Engineer as follows:
A.
If request is initiated before construction begins, the stormwater plan must be resubmitted and reviewed according to the procedures in § 216-13 of this chapter.
B.
If request is initiated after construction is underway, the Township
Engineer shall have the authority to approve or disapprove the modification,
based on field inspection, provided the requested changes in stormwater
controls do not result in any modifications to other approved Township
land use/development requirements (such as required building setbacks,
yards, etc.). (A plan modification, in accordance with applicable
Township procedures, shall be necessary if any such requirements are
affected.) The developer shall maintain a record of all changes approved
for the stormwater management controls and shall submit these to the
Township's Board of Supervisors with the final as-built plans
for the development, prior to the acceptance of any improvements by
the Township.
C.
Design modifications during construction. The developer shall submit
a written request, along with professional certifications of any modifying
calculations, with drawings describing any design modifications, and
receive written approval before continuing with the modifications
without penalty to the Township or Township Engineer conducting the
review.
A.
Stormwater management districts:
(1)
For the purposes of stormwater management, Carroll Township is considered
one stormwater management district.
(2)
At the time where the Township adopts an Act 167 Study that has provisions
for separate standards for release rates, then the prescribed release
rates shall be incorporated here in this chapter by reference at the
release rates adopted in the study.
B.
General performance standards. The following provisions shall be
considered the overriding performance standards against which all
proposed stormwater control measures shall be evaluated, and they
shall apply in all areas of the Township.
(1)
Any landowner and any person engaged in the alteration or development
of any land which may affect stormwater runoff characteristics shall
implement such measures as are reasonably necessary to prevent injury
to health, safety or other property. Such measures shall include such
actions as are required:
(a)
To assure that the maximum rate of stormwater runoff leaving
the property, as well as at all points of interest downstream of the
development within the Township boundaries, is no greater than 80%
of the predevelopment rate of discharge after development; or
(b)
To manage the quantity, velocity and direction of resulting
stormwater runoff in a manner which otherwise adequately protects
health and property from possible injury.
(2)
The stormwater management plan for the development site must consider
all the stormwater runoff flowing over the site.
(3)
Where the existing storm sewers are reasonably accessible, proposed
developments may be required to connect with the storm sewer system
unless insufficient capacity or other reasons can be demonstrated
to prevent the connection.
(4)
No discharge of toxic materials into any stormwater management system
shall be permitted.
(5)
For any development that is to be constructed in stages, the applicant
must demonstrate that stormwater facilities will be installed to manage
stormwater runoff safely during each stage of development.
(6)
Where a subdivision or land development is traversed by a natural
watercourse, there shall be provided a drainage easement or right-of-way
conforming substantially with the line of such watercourse width.
(7)
The Township will assure that all perennial or intermittent streams
not under the jurisdiction of other official agencies are maintained
open and free flowing. Fifty-foot easements shall be provided and
centered about the center line of the stream. If a perennial or intermittent
stream passes through the site, the applicant shall create a stream
buffer extending a minimum of 25 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 or a stream traverses the site, the buffer width may be reduced
to 25% of the setback and/or 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 chapter, the existing buffer
shall be maintained. [Note: The Township may select a smaller buffer
width (above) if desired, but the selected buffer may not be less
than 10 feet.] This does not include lakes or wetlands.
C.
Technical performance standards. The stormwater performance standards
contained in this section are intended to implement the standards
and criteria contained in the Carroll Township Stormwater Management
Plan. It shall be used as a guide in applying and interpreting all
specific ordinance requirements. If there is any discrepancy between
the provisions of this chapter and the standards and criteria of the
plan, or the Township Stormwater Management Plan is subsequently amended,
then the standards/criteria of the current plan shall govern. Unless
otherwise specified, the following provisions shall apply in all stormwater
management districts:
(1)
Design storms.
(a)
Stormwater management facilities on all development sites in
all stormwater management districts shall control the peak stormwater
discharge for the two-, ten-, twenty-five- and one-hundred-year design
storms. The SCS twenty-four-hour, Type II rainfall distribution shall
be used for analyzing stormwater runoff in predevelopment and post-development
conditions as well as for designing runoff control facilities (except
storm runoff collection and conveyance facilities). The design storms,
along with the twenty-four-hour total runoff depths for these return
periods, for the watersheds in Carroll Township are:
|
Design Storm Return Period
|
24-Hour Rainfall Depth
(inches)
| |
|---|---|---|
|
2-year
|
2.6
| |
|
10-year
|
3.9
| |
|
25-year
|
4.4
| |
|
100-year
|
5.2
|
(b)
For additional information or data on other return periods,
consult the Rainfall Duration Frequency Tables for Pennsylvania produced
by the Pennsylvania Department of Environmental Protection, Office
of Resource Management, Bureau of Dams and Waterways Management, Division
of Stormwater Management, Harrisburg, February 1983.
(2)
Calculation methods.
(a)
Development sites. For the purposes of computing peak flow rates
and runoff hydrographs from development sites and drainage areas larger
than three acres, calculations shall be performed using the methodologies
presented in SCS Publication, Technical Release 55 (TR55). For development
sizes less than three acres, the Rational Method may be utilized.
The Township Engineer may approve the use of other simulation computer
programs for the stormwater analysis and design.
(b)
Stormwater collection/conveyance facilities. For the purpose
of designing storm sewers, open swales and other stormwater runoff
collection and conveyance facilities, the Rational Method shall be
applied. Rainfall intensities for the one-hundred-year storm shall
be used. Rainfall intensities for design should be obtained from the
current Pennsylvania Department of Transportation rainfall charts.
(c)
Predevelopment conditions. Predevelopment conditions shall be
assumed to be those which exist on any site at the time of plan submission.
Hydrologic conditions for all areas with pervious cover (i.e., fields,
woods, lawn areas, pastures, cropland, etc.) shall be assumed to be
in "good" condition, and the lowest recommended SCS runoff curve number
(CN) shall be applied for pervious land uses within the respective
range for each land use and hydrologic soil group.
(3)
Release rate percentage.
(a)
Application. All subdivisions and land development activities
which result in an increase in the post-development peak rate of stormwater
runoff from any outfall on the development site shall be subject to
the eighty-percent release rate as applied to the design storms [two-,
ten-, twenty-five-, one-hundred-year events]. In the event an Act
167 watershed management plan is adopted by resolution, then the release
rates for subsheds or the areas of the Township designated in the
plan or presented by resolutions shall supersede this value without
modification being required to this chapter.
(b)
Definition. The release rate percentage defines the percentage
of the predevelopment peak rate of runoff rate that can be discharged
from an outfall on the site after development. It applies uniformly
to all land developments or alterations within a subarea, and the
post-development rate of runoff discharging from each outfall of the
development site cannot exceed the release rate percentage for the
subarea in which it is located.
A.
General design guidelines.
(1)
Applicants may select runoff control techniques or combinations of
techniques which are most suitable to the level of stormwater runoff
control required, the type of development, and the natural features
of the site and the effects of increased runoff to downstream areas.
Cost of maintenance may be one of the considerations in the designs
selected. All controls are subject to the approval of the Township
Engineer. The Engineer may request specific information on design
and/or operating features of the proposed stormwater controls in order
to determine their suitability and adequacy in terms of the standards
of this chapter.
(2)
In selecting and designing stormwater management systems, and controls,
applicants may be guided by the following references:
(a)
Urban Hydrology for Small Watersheds, Technical Release No.
55, United States department of Agriculture, Natural Resources Conservation
Service (formerly SCS), 1975 (or most recent edition).
(b)
Soil Erosion and Sedimentation Control Manual, Pennsylvania
Department of Environmental Protection, March 1982.
(c)
Standards and Specifications for Soil Erosion and Sediment Control,
Maryland Water Resources Administration, 1983.
(d)
Urban Stormwater Management, Special Report No. 49, American
Public Works Administration, 1981.
(e)
Water Resources Protection Measures in Land Development - A
Handbook, University of Delaware, Water Resources Center, April 1974.
(f)
Design and Construction of Sanitary and Storm Sewers, WPCF Manual
of Practice No. 9, Water Pollution Control Federation, 1970.
(3)
The applicant should consider the effect on the proposed stormwater
management techniques of any special soils conditions or geological
hazards which may exist on the development site. In the event such
conditions are identified on the development site, the Township may
require in-depth studies by a competent geotechnical engineer.
B.
Criteria for stormwater detention facilities.
(1)
If detention facilities are utilized for the development site, the
facility(ies) shall be designed such that the post-development peak
runoff rates from the developed site are controlled to eighty-percent
release rate percentage or downstream impact evaluation for the two-,
ten-, twenty-five- and one-hundred-year design storms.
(2)
All detention facilities shall be designed and equipped to safely
pass the post-development one-hundred-year storm runoff flows without
damaging (i.e., impairing the continued function of) the facilities.
(The twenty-four-hour total rainfall for the one-hundred-year storm
is 5.2 inches.) The one-hundred-year storm shall be passed by the
facility with a minimum one foot of freeboard.
(3)
Shared storage facilities, which provide detention of runoff for
more than one development site, may be considered within a single
subarea. Such facilities shall meet the design criteria contained
in this section. In addition, runoff from the development sites involved
shall be conveyed to the facility in a manner so as to avoid adverse
impacts, such as flooding or erosion, to channels and properties located
between the development site and the shared storage facilities.
(4)
Where detention facilities will be utilized, multiple-use facilities,
such as lakes, ball fields, or similar recreational uses, are encouraged
wherever feasible, subject to the approval of the Township.
(5)
Other considerations which should be incorporated into the design
of the detention facilities include:
(a)
Inflow and outflow structures should be designed and installed
to prevent erosion, and bottoms of impoundment-type structures should
be protected from soil erosion.
(b)
Control and removal of debris both in the storage structure
and in all inlet or outlet devices will be a design consideration.
(c)
Inflow and outflow structures, pumping stations, and other structures
should be protected and designed to minimize safety hazards.
(d)
The interior slope of a detention or retention basin shall be
no steeper than three to one (horizontal to vertical). Restriction
of access (fences, walls, etc.) may be required, depending on location
of the facility and the recommendation of the Township Engineer.
(e)
Ponds with a normal water depth greater than 10 feet shall require
a supporting report from a geotechnical engineer and shall be constructed
under the supervision of the geotechnical engineer.
(f)
Landscaping should be provided for the facility which harmonizes
with the surrounding area.
(g)
Facility should be located to facilitate maintenance, considering
the frequency and type of equipment that will be required.
(h)
All principal spillway inlets in any detention or retention
facility must have an appropriate trash rack that facilitates self-cleaning.
(i)
For all underground detention facilities, exclusive of those
used for residential small developments, two points of access will
be required for maintenance and safety.
(j)
All aboveground detention facilities shall have a low-flow channel
of noneroding materials, as approved by the Township Engineer, to
prevent erosion during low-flow periods, with four inches' PVC underdrain.
(k)
All interior portions of the basin shall slope toward the outlet
or low-flow channel at a minimum of 1%.
(6)
Control facilities shall be designed to meet, as a minimum, the design
standards and specifications of the Erosion and Sedimentation Control
Handbook for Townships and Counties.
(a)
In areas underlain with limestone geology, ponds shall be limited
to the detention (dry) type unless the developer can show a special
need for a retention pond, in which case it shall have a lining. Detention
ponds shall be prohibited in areas of known sinkholes unless the pond
is lined.
(b)
Retention ponds deeper than four feet shall be fenced with a
six-foot-high fence, subject to the approval of the Board of Supervisors.
The fencing requirement may be waived by the Board of Supervisors
if it can be demonstrated that fencing is not needed to protect the
public health and safety.
C.
Criteria for collection/conveyance facilities.
(1)
All stormwater runoff collection or conveyance facilities, whether
storm sewers or other open or closed channels, shall be designed in
accordance with the following basic standards:
(a)
All sites shall be graded to provide drainage away from and
around the structure in order to prevent any potential flooding damage.
(b)
Lots located on the high side of streets may extend roof and
french drains to a properly sized curbline storm sewer (if applicable).
Low side lots may extend roof and french drains to a stormwater collection/conveyance
system or natural watercourse in accordance with the approved stormwater
management plan for the development site.
(c)
Collection/conveyance facilities should not be installed parallel
and close to the top or bottom of a major embankment to avoid the
possibility of failing or causing the embankment to fail.
(d)
All collection/conveyance facilities shall be designed to convey
the one-hundred-year storm peak flow rate from the contributing drainage
area and to carry it to the nearest suitable outlet such as a curbed
street, storm sewer, or natural watercourse. Off-site conveyance shall
be via public or private easement to an existing storm sewer system
or natural watercourse.
(e)
Collection/conveyance facilities shall be designed as a system
and shall address which criteria, inlet, outlet or pipe flow conditions
control. No part of the collection/conveyance system shall be designed
for pressure flow. One foot of freeboard shall be maintained in inlets
at peak design flows. Collection/conveyance systems shall be designed
to handle the fully developed site.
(f)
Where drainage swales or open channels are used, they shall
be suitably lined to prevent erosion and designed to avoid excessive
velocities.
(2)
Wherever storm sewers are proposed, they shall comply with the following
criteria:
(a)
Where practical, designed to traverse under seeded and planted areas. If constructed within a road or street right-of-way dedicated to the Township, the storm sewer shall be constructed in accordance with the standards required in Chapter 225, Subdivision and Land Development.
(b)
Preferably installed after excavating and filling in the area
to be traversed is completed, unless the drain is installed in the
original ground with a minimum of two feet of cover and/or adequate
protection during the fill construction.
(c)
Designed: 1) with cradle when traversing fill areas of indeterminate
stability; 2) with anchors when gradient exceeds 20%; and 3) with
encasement or special backfill requirements when traversing under
a paved area.
(d)
Designed to handle adequately the anticipated stormwater flow
and to be constructed and maintained economically. The minimum pipe
size shall be 15 inches in diameter.
(e)
Drain pipe, head walls, end walls, trenching, bedding and backfilling
requirements shall conform to the requirements of the Township and/or
applicable requirements of the Pennsylvania Department of Highways
Specifications, current Form 408.
(f)
All piping shall be smooth-flow corrugated polyethylene pipe
with soil-tight joint systems, such as ADS N-12® or similar. Other
pipe may be used upon approval by the Township Engineer.
(g)
Storm inlets and structures shall be designed to be adequate,
safe, self-cleaning and unobtrusive and shall be consistent with the
standards of the Township.
(h)
Appropriate grates shall be designed for all catch basins, stormwater
inlets and other entrance appurtenances in accordance with Township
specifications.
(i)
Manholes shall be designed so that the top shall be at finished
grade and sloped to conform to slope of finished grade. Top castings
of structures located in roads or parking areas shall be machined
or installed to preclude rattling.
(j)
Where a proposed storm sewer connects with an existing storm
sewer system, the applicant shall demonstrate that sufficient capacity
exists in the downstream system to handle the additional stormwater
flow.
(k)
Storm sewer outfalls shall be equipped with energy dissipation
to prevent erosion and conform to applicable requirements of the PADEP
for stream encroachments (Chapter 105 of the Department's Rules
and Regulations).
(l)
All footer drains and floor drains shall be collected and conveyed
to the nearest stormwater management facility.
(m)
Street drainage will not be permitted to cross intersections
or the crown of the road.
(n)
Maximum spacing of street inlets shall not exceed 400 feet.
(3)
All springs and sump pump discharges shall be collected so as not
to flow in the streets or cause damage to adjacent property.
(4)
Stormwater roof drains shall be collected and conveyed to the nearest
stormwater management facility.
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 virus prevention guidance from the EPA.
C.
Any stormwater management facility (i.e., detention basin) required
or regulated by this chapter 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 the Department of Environmental
Preservation.
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 one-hundred-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.
Storm sewers must be able to convey proposed conditions runoff from
a one-hundred-year design storm maintaining a one-foot freeboard from
the top of the inlet grate.
H.
Adequate erosion protection shall be provided along all open channels
and at all points of discharge.
I.
The design of all stormwater management facilities shall incorporate
sound engineering principles and practices. The Township reserves
the right to disapprove any design that would result in construction
in or continuation of a stormwater problem area.
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 § 216-1 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. Appropriate soils testing and/or geotechnical evaluation should be included as part of any documentation for infiltration BMPs. If it can be physically accomplished, then the volume of runoff to be infiltrated shall be determined from § 216-19A(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, preferably 36 inches, between
the bottom of the BMP and the top of the limiting zone (e.g., SHWT,
groundwater, bedrock, etc.).
(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) within
three days (72 hours) or less.
(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 post-development
hydrograph, drawing a straight line from the point-of-inflection of
the rising limb of the hydrograph to the predevelopment two-year storm.
(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 § 216-19A(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 Subsection A(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 = I * impervious area (square feet)
÷ 12 (inches) = cubic feet (cf)
| ||
|---|---|---|
|
An asterisk (*) in equations denotes multiplication.
| ||
|
Where:
| ||||
|---|---|---|---|---|
|
I
|
=
|
Maximum equivalent infiltration amount (inches) that the site
can physically accept or 0.50 inch, whichever is greater.
| ||
(d)
The retention volume values derived from the methods in Subsection A(2)(a), (b) and/or (c) are the minimum volumes 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.
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. Percolation
tests are not recommended 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 the Township that
the soils are conducive to infiltrate on the lots identified.
C.
Stormwater hot spots.
(1)
Below is a list of examples of designated hot spots. If a site is
designated as a hot spot, it has important implications for how stormwater
is managed. First and foremost, untreated stormwater runoff from hot
spots 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 hot spot category (the entire WQv must
still be treated). Second, a greater level of stormwater treatment
shall be considered at hot spot sites to prevent pollutant washoff
after construction. The Environmental Protection Agency' (EPA)
NPDES stormwater program requires some industrial sites to prepare
and implement a stormwater pollution prevention plan. Examples of
hot spots:
|
•
|
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
|
(2)
The following land uses and activities are not normally considered
hot spots:
|
•
|
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]
|
(3)
While large highways [average daily traffic volume (ADT) greater
than 30,000] are not designated as stormwater hot spots, 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 township 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. A qualified
design professional shall evaluate the possibility of groundwater
contamination from the proposed infiltration facility and perform
a hydrogeologic justification study if necessary. Specific consideration
should be given to the particular type of salt or deicing material
to be used within this watershed in regards to its potential long-term
effects on the soils, especially in areas that contain clay soil.
G.
The infiltration requirement in HQ or EV waters shall be subject
to the PADEP Chapter 93 Antidegradation Regulations.
A.
No regulated earth disturbance activities within the Township shall
commence until approval by the Township of a best management practices
(BMPs) operations and maintenance plan which describes how the permanent
(e.g., post-construction) stormwater BMPs will be properly operated
and maintained.
B.
The BMPs must be designed to protect and maintain existing uses (e.g.,
drinking water use, cold water fishery use) and maintain the level
of water quality necessary to protect those uses in all streams, and
to protect and maintain water quality in "special protection" streams,
as required by statewide regulations at 25 Pa. Code Chapter 93 (collectively
referred to herein as "state water quality requirements").
C.
To control post-construction stormwater impacts from regulated earth
disturbance activities, state water quality requirements can be met
by BMPs, including site design, which provide for replication of preconstruction
stormwater infiltration and runoff conditions, so that post-construction
stormwater discharges do not degrade the physical, chemical or biological
characteristics of the receiving waters. As described in the DEP Comprehensive
Stormwater Management Policy (No. 392-0300-002, September 28, 2002),
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 chemical and physical pollutants from the stormwater runoff;
and
(3)
Stream bank and streambed protection. Management of volume and rate
of post-construction stormwater discharges to prevent physical degradation
of receiving waters (e.g., from scouring and erosion).
D.
The Department of Environmental Protection has regulations that require
municipalities to ensure design, implementation and maintenance of
best management practices (BMPs) that control runoff from new development
and redevelopment (hereinafter "development") after regulated earth
disturbance activities are complete. These requirements include the
need to implement post-construction stormwater BMPs with assurance
of long-term operations and maintenance of those BMPs.
E.
Evidence of any necessary permit(s) for regulated earth disturbance activities from the appropriate DEP regional office or county conservation district must be provided to the Township. The issuance of an NPDES construction permit (or permit coverage under the statewide general permit (PAG-2) satisfies the requirements of § 216-20A.
A.
Erosion and sedimentation controls shall be provided, both during and after construction, in accordance with the provisions of Chapter 138, Grading and Excavation, Article II, Erosion and Sediment Control, and any state/county regulations, specifically Title 25 Pa. Code Chapter 102 Rules and Regulations.
B.
Proposed erosion/sedimentation measures should be submitted with
the stormwater management plan as part of the applicant's preliminary
plans.
A.
The Township Engineer or a designated representative shall inspect
the construction of the temporary and permanent stormwater management
for the development site. The permittee shall notify the Engineer
48 hours in advance of the completion of the following key development
phases:
(1)
At the completion of preliminary site preparation, including stripping
of vegetation, stockpiling of topsoil, and construction of temporary
stormwater management and erosion control facilities.
(2)
At the completion of rough grading, but prior to placing topsoil,
permanent drainage, or other site development improvements and ground
covers.
(3)
During construction of the permanent stormwater facilities at such
times as specified by the Township Engineer.
(4)
Completion of permanent stormwater management facilities, including
established ground covers and plantings.
(5)
Completion of any final grading, vegetative control measures, or
other site restoration work done in accordance with the approved plan
and permit.
B.
No work shall commence on any subsequent phase until the preceding
one has been inspected and approved. If there are deficiencies in
any phase, the Township Engineer shall issue a written description
of the required corrections and stipulate the time by which they must
be made.
C.
If during construction the contractor or permittee identifies any
site conditions, such as subsurface soil conditions, alterations in
surface or subsurface drainage, which could affect the feasibility
or approved operating requirements of the approved stormwater facilities,
he must notify the Township Engineer within 24 hours of the discovery
of such condition and request a field inspection. The Township Engineer
shall determine if the condition requires a stormwater plan modification.
D.
In cases where stormwater facilities are to be installed in areas
of landslide-prone soils or other special site conditions exist, the
Township may require special precautions such as soil tests and core
borings, full-time resident inspectors, and/or similar measures. All
costs of any such measures shall be borne by the permittee.
A.
The Township staff and 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 Township representative or Municipal
Engineer or his designee determines that the permanent BMPs and/or
stormwater management facilities are not being installed in accordance
with the approved stormwater management plan, the Township 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 chapter 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 the Township to defray administrative costs, Township staff review and inspection costs incurred by the Township. These fees are separate from review and inspection fees in Chapter 225, Subdivision and Land Development. All fees shall be paid by the applicant at the time of the stormwater management plan or drainage plan submission. A review and inspection fee schedule shall be established by resolution of the Township based on the size of the regulated activity and based on the Township's costs for reviewing drainage plans and conducting inspections pursuant to § 216-22. The Township shall periodically update the review and inspection fee schedule to ensure that review costs are adequately reimbursed.
The fees required by this chapter shall at a minimum cover:
A.
Administrative costs.
B.
The administrative costs related to review of the drainage plans
by the Township officials and staff.
C.
The administrative costs related to site inspections.
D.
The administrative costs related to inspection by the Township of
stormwater management facilities and drainage improvements during
construction.
E.
The administrative costs related to final inspection upon completion
of the stormwater management facilities and drainage improvements
presented in the drainage plan.
F.
Any additional work required to enforce any permit provisions regulated
by this chapter, correct violations, and assure proper completion
of stipulated remedial actions.
G.
Public stormwater protection awareness programs and compliance programs
for compliance with stormwater regulations, including GIS mapping
and maps, newspaper ads, pamphlets, leaflets, etc., deemed as appropriate
by the Township Supervisors. Public stormwater protection awareness
programs will be as defined by the Township Supervisors.
A.
No regulated earth disturbance activities within the Township shall
commence until approval by the Township of a stormwater control and
BMP operations and maintenance plan that describes how the permanent
(e.g., post-construction) 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 Washington
County, shall be submitted on twenty-four-inch by thirty-six-inch
sheets. The contents of the map(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 drainagecourses, and areas of natural vegetation
to be preserved;
(f)
The locations of all existing and proposed utilities, sanitary
sewers, water wells, and waterlines within the project parcel and
to 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 road
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 the 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 the Township, stormwater controls and BMPs
may also be dedicated to and maintained by the Township.
(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.
The Township shall make the final determination on the continuing
operations and maintenance responsibilities. The Township reserves
the right to accept or reject the operations and maintenance responsibility
for any or all of the stormwater controls and BMPs.
A.
The Township shall review the stormwater control and BMP operations
and maintenance plan for consistency with the purposes and requirements
of this chapter and any permits issued by DEP.
B.
The Township shall notify the applicant in writing whether or not
the stormwater control and BMP operations and maintenance plan is
approved.
C.
The Township may require a record drawing of all stormwater controls
and BMPs and an explanation of any discrepancies with the operations
and maintenance plan.
D.
In cases where stormwater facilities are to be installed in areas
of landslide-prone soils or other special site conditions exist, the
Township may require special precautions such as soil tests and core
borings, full-time resident inspectors, and/or similar measures. All
costs of any such measures shall be borne by the permittee.
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 the 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 F of this chapter.[1]
[1]
Editor's Note: Appendix F is on file in the Township's office.
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 the 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 § 216-29.
A.
Prior to final approval of the site's drainage plan, the applicant
shall sign and record the maintenance agreement contained in Appendix
E,[1] which is attached and made part hereof, covering all stormwater
control facilities that are to be privately owned.
[1]
Editor's Note: Appendix E is on file in the Township's office.
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 governing body.
For subdivisions and land developments, the applicant shall
provide a financial guarantee to the Township for the timely installation
and proper construction of all stormwater management controls as:
A.
Required by the approved stormwater management plan equal to or greater
than the full construction cost of the required controls. The construction
costs shall be estimated by the developer's consultant or an
actual contractor's proposal and only as approved by the Township's
review engineer. The amount of the security shall provide 110% of
the construction estimated costs.
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 Washington County within 15 days of approval of the stormwater
control and BMP operations and maintenance plan by the Township:
B.
The Township 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 storage facilities shall be required
to pay a specified amount to the municipal stormwater maintenance
fund to help defray costs of periodic inspections and maintenance
expenses. The amount of the deposit shall be determined as follows:
(1)
If the storage facility is to be privately owned and maintained,
the deposit shall cover the cost of periodic inspections and maintenance
performed by the Township for a period of five years, as estimated
by the Township Engineer. After that period of time, inspections will
be performed at the expense of the Township.
(2)
If the storage facility is to be owned and maintained by the Township,
the deposit shall cover the estimated costs for maintenance and inspections
for five years. The Township 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 Township Engineer shall determine
the present worth equivalents, which shall be subject to the approval
of the Board of Supervisors.
B.
If a storage facility is proposed that also serves as a recreation
facility (e.g., ball field, lake), the Township may reduce or waive
the amount of the maintenance fund deposit based upon the value of
the land for public recreation purposes.
C.
If a storage facility (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 not be refunded
to the applicant, but remain for use in maintenance of other facilities
for stormwater used in the Township. If a storage facility (whether
publicly or privately owned) is eliminated within five years of acceptance
for use, the unused portion shall 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
shall be used for improvements or upgrades to the Township's
stormwater facilities, but shall not be refunded to the applicant.
D.
If the facility is not eliminated after five years, the remaining
amount of fees in the fund shall be used for improvements or upgrades
to the Township's stormwater facilities or the Township stormwater
compliance and public awareness program, but shall not be refunded
to the applicant. If the Township adopts a stormwater utility or user
rate in the future, the availability of this fee to be added to the
general revenue will be considered by the Township Supervisors at
that time.
(Note: The following language, taken from DEP's NPDES program
and model NPDES ordinance, is required to be incorporated into this
chapter.)
A.
No person in the Township shall allow, or cause to allow, stormwater discharges into the Township's separate storm sewer system which are not composed entirely of stormwater, except: 1) as provided in Subsection B below; and 2) discharges allowed under a state or federal permit.
B.
Discharges that may be allowed based on a finding by the Township
that the discharge(s) do not significantly contribute to pollution
to surface waters of the commonwealth, are:
(1)
Discharges from fire-fighting activities.
(2)
Uncontaminated water from foundation or from footing drains.
(3)
Potable water sources including dechlorinated waterline and fire
hydrant flushings.
(4)
Flows from riparian habitats and wetlands.
(5)
Lawn watering.
(6)
Irrigation drainage.
(7)
Pavement wash waters where spills or routine external building washdown
does not use detergents or other compounds.
(8)
Air-conditioning condensate where leaks of toxic or hazardous materials
have not occurred (unless all spill material has been removed) and
where detergents are not used.
(9)
Water from individual residential car washing.
(10)
Dechlorinated swimming pool discharges.
(11)
Spring water from crawl space pumps.
(12)
Uncontaminated groundwater.
C.
In the event that the Township determines that any of the discharges identified in Subsection B significantly contribute to pollution of waters of the commonwealth, or is so notified by the DEP, the Township will notify the responsible person to cease the discharge.
D.
Upon notice provided by the Township under Subsection C, the discharger will have a reasonable time, as determined by the Township, to cease the discharge consistent with the degree of pollution caused by the discharge.
E.
Nothing in this section shall affect a discharger's responsibilities
under state law.
The following connections are prohibited, except as provided in § 216-35B above:
A.
Any drain or conveyance, whether on the surface or subsurface, which
allows any nonstormwater discharge including sewage, process wastewater,
and wash water to enter the separate storm sewer system and any connections
to the storm drain system from indoor drains and sinks; and
B.
Any drain or conveyance connected from a commercial or industrial
land use to the separate storm sewer system which has not been documented
in plans, maps or equivalent records and approved by the Township.
A.
Roof drains shall not be connected to streets, sanitary or storm
sewers, or roadside ditches 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 the 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 Township.
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 the Township.
A.
Upon presentation of proper credentials, duly authorized representatives
of the Township may enter at reasonable times upon any property within
the Township to inspect the implementation, condition or operation
and maintenance of the stormwater controls or BMPs in regard to any
aspect governed by this chapter.
B.
Stormwater control and BMP owners and operators shall allow persons
working on behalf of the Township ready access to all parts of the
premises for the purposes of determining compliance with this chapter.
C.
Persons working on behalf of the Township shall have the right to
temporarily locate on any stormwater control or BMP in the Township
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 Township access to a stormwater
control or BMP is a violation of this chapter.
A.
Whenever the Township finds that a person has violated a prohibition
or failed to meet a requirement of this chapter, the Township 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 violation(s). Said
notice may further advise that, if applicable, should the violator
fail to take the required action within the established deadline,
the work will be done by the Township or designee, and the expense
thereof shall be charged to the violator.
C.
Failure to comply within the time specified shall also subject such
person to the penalty provisions of this chapter. All such penalties
shall be deemed cumulative and shall not prevent the Township from
pursuing any and all other remedies available in law or equity.
A.
Any building, land development, or other permit or approval issued
by the Township may be suspended or revoked by the Township for:
(1)
Noncompliance with or failure to implement any provision of the permit;
(2)
A violation of any provision of this chapter; 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 Township
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 chapter.
A.
Any person violating the provisions of this chapter shall be subject
to a fine of not less than $100 nor more than $1,000 for each violation,
recoverable with costs.
B.
Each day that the violation continues shall constitute a separate
offense and the applicable fines are cumulative.
C.
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 chapter. 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 chapter 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 chapter. 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 chapter.
The municipal governing body is hereby authorized and directed
to enforce all of the provisions of this chapter. All inspections
regarding compliance with the drainage plan shall be the responsibility
of the Municipal Engineer or other qualified persons designated by
the Township.
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 § 216-6 on any property except as provided for in the approved drainage plan and pursuant to the requirements of this chapter. It shall be unlawful to alter or remove any control structure required by the drainage plan pursuant to this chapter 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 the Township, a final inspection
shall be conducted by the Municipal Engineer or designated representative
to certify compliance with this chapter.
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.
F.
Occupancy permit. An occupancy permit shall not be issued unless
the certification of completion pursuant has been secured. The occupancy
permit shall be required for each lot owner and/or applicant for all
subdivisions and land developments in the Township.
A.
Any person aggrieved by any action of Carroll Township or its designee
may appeal to the Carroll Township Board of Supervisors within 30
days of that action.
B.
Any person aggrieved by any decision of the Carroll Township Board
of Supervisors 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.
A.
Neither the granting of any approval under the stormwater management
provisions of this chapter nor the compliance with the provisions
of this chapter or with any condition imposed by a Township official
hereunder shall relieve any person from any responsibility for damage
to persons or property resulting therefrom, or as otherwise imposed
by law, nor impose any liability upon the Township for damages to
persons or property.
B.
The granting of a permit which includes any stormwater management
facilities shall not constitute a representation, guarantee or warranty
of any kind by the Township, or by an official or employee thereof,
of the practicability or safety of any structure, use or other plan
proposed, and shall create no liability upon or cause of action against
such public body, official or employee for any damage that may result
pursuant thereto.
