[HISTORY: Adopted by the Board of Commissioners of the Township
of Crescent 9-12-2007 by Ord. No.
509; amended in its entirety 12-11-2014 by Ord. No. 556. Subsequent amendments
noted where applicable.]
GENERAL REFERENCES
Attachment 1 - Appendix A, Flaugherty Run Watershed Stormwater Management PlanFloodplain construction, development and management — See Ch. 230.
Zoning — See Ch. 430.
Subdivision and land development — See Ch. 440.
Storm sewers and drainage facilities — See Ch. 446.
Attachment 2 - Appendix B, Standard Schedule for Maintenance of Stormwater Management Facilities
Attachment 3 - Appendix C, Low-Impact Development Practices Alternative Approach for Managing Stormwater Runoff
Attachment 4 - Appendix D, Stormwater Best Management Practices Operations and Maintenance Agreement
Attachment 5 - Appendix E, WorksheetsThe governing body of the municipality finds that:
A.
Stormwater runoff from lands modified by human activities threatens
public health and safety by causing decreased infiltration of rainwater
and increased runoff flows and velocities, which overtax the carrying
capacity of existing streams and storm sewers, and greatly increases
the cost to the public to manage stormwater.
B.
Public education on the control of pollution from stormwater is an
essential component in successfully addressing stormwater.
C.
Nonstormwater discharges to municipal separate storm sewer systems
can contribute to pollution of waters of the commonwealth.
D.
Inadequate maintenance of stormwater facilities contributes to erosion
and sedimentation, overtaxes the carrying capacity of streams and
storm sewers, increases the cost of public facilities to carry and
control stormwater, undermines floodplain management and flood control
efforts in downstream communities, reduces groundwater recharge, threatens
public health and safety, and increases pollution of water resources.
E.
Stormwater is an important water resource, which provides groundwater
recharge for water supplies and base flow of streams, which also protects
and maintains surface water quality.
F.
Federal and state regulations require certain municipalities to obtain
a permit for stormwater discharges from their separate storm sewer
systems under the National Pollutant Discharge Elimination System
(NPDES). Permittees are required to enact, implement, and enforce
a prohibition of nonstormwater discharges to the permittee's
regulated small municipal separate storm sewer systems (MS4s).
This chapter is adopted and implemented to achieve the following
general purposes and objectives:
B.
To manage stormwater runoff resulting from land alteration and disturbance
activities in accordance with the Flaugherty Run Watershed stormwater
management plan adopted by Allegheny County as required by the Pennsylvania
Storm Water Management Act (Act 167 of 1978, as amended);
C.
To utilize and preserve the desirable existing natural drainage systems
and to preserve the flood-carrying capacity of streams;
D.
To encourage natural infiltration of rainfall to preserve groundwater
supplies and stream flows; and
E.
To provide for adequate maintenance of all permanent stormwater management
facilities in the Township.
F.
Infiltration BMPs should be spread out and shallow as much as practicable.
The municipality also is empowered to regulate land use activities
that affect runoff by the authority of the Act of July 31, 1968, P.L.
805, No. 247, the Pennsylvania Municipalities Planning Code, as amended.[1]
[1]
Editor's Note: See 53 P.S. § 10101 et seq.
Stormwater management facilities shall be provided for subdivisions,
land developments, and all activities which change the slope of the
land or the land cover and shall be designed to ensure that the maximum
rate of stormwater runoff from the site shall be no greater after
development than is the rate of runoff from the site prior to development,
and be subject to release rates within the Flaugherty Run watershed.
This chapter shall repeal all other code provisions or parts
thereof, which are contrary to or conflict with the provisions of
this chapter to the extent necessary to give this chapter full force
and effect.
Should any part of this chapter be declared invalid, such decision
shall not affect the validity of any other part, nor the article as
a whole.
Actions taken under this chapter do not affect any responsibility,
permit or approval for any activity regulated by any other code, law,
regulation, or ordinance.
For the purposes of this chapter, the terms used herein shall
have the following definitions. The words "shall" and "must" shall
be mandatory, single and plural, and feminine and masculine are equivalent.
- AGRICULTURAL ACTIVITY
- Activities associated with agriculture such as agricultural cultivation, agricultural operation, and animal heavy use areas. This includes the work of producing crops including tillage, land clearing, plowing, disking, harrowing, planting, harvesting crops or pasturing and raising of livestock and installation of conservation measures. Construction of new buildings or impervious area is not considered an agricultural activity.
- APPLICANT
- A landowner or developer, as defined by this chapter who has filed an application for development, including his/her heirs, successors and assigns.
- BMP
- Best management practice activities, facilities, designs, measures, or procedures used to manage stormwater impacts from regulated activities, to meet state water quality requirements, to promote groundwater recharge, and to otherwise meet the purposes of this chapter. Stormwater BMPs are commonly grouped into one of two broad categories or measures: structural or nonstructural. In this chapter, nonstructural BMPs or measures refer to operational and/or behavior-related practices that attempt to minimize the contact of pollutants with stormwater runoff whereas structural BMPs or measures are those that consist of a physical device or practice that is installed to capture and treat stormwater runoff. Structural BMPs include, but are not limited to, a wide variety of practices and devices, from large-scale retention ponds and constructed wetlands, to small-scale underground treatment systems, infiltration facilities, filter strips, low-impact design, bioretention, wet ponds, permeable paving, grassed swales, riparian or forested buffers, sand filters, detention basins, and manufactured devices. Structural stormwater BMPs are permanent appurtenances to the project site.
- CHANNEL
- A natural stream that conveys water; a man-made ditch or open channel excavated for the flow of water.
- CONSERVATION DISTRICT
- The Allegheny County Conservation District (ACCD).
- COUNTY
- The County of Allegheny, Pennsylvania.
- CULVERT
- A closed conduit for the free passage of surface drainage under a highway, railroad, canal, or other embankment.
- DEP
- The Pennsylvania Department of Environmental Protection.
- DESIGN CRITERIA
- Engineering guidelines specifying construction details and materials, or objectives, results, or limits which must be met by a facility, structure or process in performance of its intended functions.
- DESIGN STORM
- The magnitude of precipitation from a storm event, measured in probability of occurrence, such as the one-hundred-year storm, and duration, such as twenty-four-hour, and used in designing stormwater management control systems.
- DETENTION
- The slowing, dampening, or attenuating of runoff entering the natural drainage pattern or storm drainage system by temporarily holding water in areas such as detention basins, reservoirs, rooftops, streets, parking lots, or within the drainage system itself.
- DETENTION BASIN
- A basin designed to retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. A detention basin is designed to drain completely after a storm; also called a dry basin.
- DEVELOPER
- Any landowner, agent of such landowner or tenant with the permission of such landowner who makes or causes to be made a subdivision or land development.
- DEVELOPMENT
- Any activity, construction, alteration, changes in land use or similar action that affects stormwater runoff characteristics.
- DEVELOPMENT SITE
- A lot, parcel or tract of land on which development is taking place or is proposed.
- DISCHARGE RATE
- The rate of flow, specifically fluid flow. A volume of fluid (in this case water) per unit of time flowing in or from a conduit or channel, usually expressed in cubic feet per second.
- DRAINAGE
- The interception and conveyance of excess surface water or groundwater from land by artificial or natural means.
- DRAINAGE AREA
- The area which contributes runoff to a designated point of a drainage system usually expressed in acres or square miles; also called a catchment area, watershed, or river basin.
- DRAINAGE EASEMENT
- A right granted by a landowner to a grantee allowing the use of private land for stormwater management purposes.
- EARTH DISTURBANCE ACTIVITY
- A construction or other human activity which disturbs the surface of the land, including, but not limited to: clearing and grubbing; grading; excavations; embankments; road maintenance; building construction; and the moving, depositing, stockpiling, or storing of soil, rock, or earth materials.
- EMBANKMENT
- A mound of earth or stone constructed above the natural ground surface, and in stormwater management, with the specific purpose of detaining or diverting stormwater runoff.
- ENGINEER
- The professional engineer duly appointed as the engineer for the Township.
- EROSION
- The wearing away of the land surface by running water, wind, ice, or other geologic agents, including such process as gravitational creep.
- EROSION CONTROL
- The application of measures to reduce erosion of land surfaces.
- FLAUGHERTY RUN WATERSHED
- The entire area drained by Flaugherty Run as delineated by the Pennsylvania Department of Environmental Protection in the Flaugherty Run Watershed stormwater management plan.
- FLAUGHERTY RUN WATERSHED STORMWATER MANAGEMENT PLAN
- The plan for managing stormwater runoff throughout the Flaugherty Run Watershed adopted by Allegheny County as required by the Pennsylvania Stormwater Management Act.
- FLOODPLAIN
- 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) and regulations pursuant to the Act define the floodplain as the area inundated by the one-hundred-year flood and delineated on a map by FEMA (Federal Emergency Management Agency) or by the applicant in accordance with Township Code requirements.
- FOREST MANAGEMENT/TIMBER OPERATIONS
- Planning and activities necessary for the management of forestland. These include conducting a timber inventory, preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation, and reforestation.
- GROUND COVER
- Materials covering the ground surface.
- GROUNDWATER RECHARGE
- Replenishment of groundwater by infiltration, naturally by precipitation or runoff or artificially by spreading or injection.
- HYDRAULICS
- The branch of science concerned with the mechanics of fluids, especially liquids. As applied in stormwater management, the study of the characteristics of water flowing in conveyance channels, and from control facilities.
- HYDROLOGIC SOIL GROUP
- Infiltration rates of soils vary widely and are affected by subsurface permeability as well as surface intake rates. Soils are classified into four HSGs (A, B, C, and D) according to their minimum infiltration rate, which is obtained for bare soil after prolonged wetting. The NRCS defines the four groups and provides a list of most of the soils in the United States and their group classification. The soils in the area of the development site may be identified from a soil survey report that can be obtained from local NRCS offices or conservation district offices. Soils become less pervious as the HSG varies from A to D (NRCS[1]).
- HYDROLOGY
- The science dealing with waters of the earth and their distribution and circulation through the atmosphere.
- IMPERVIOUS MATERIAL
- Material which resists the entrance or passing through of water or other liquids.
- IMPERVIOUS SURFACE
- A surface that prevents the infiltration of water into the ground. Impervious surface includes, but is not limited to, any roof, parking or driveway areas, and any new streets and sidewalks. Any surface areas designed to initially be gravel or crushed stone shall be assumed to be impervious surfaces.
- INFILTRATION
- The flow or movement of water through the interstices or pores of a soil or other porous medium, or the absorption of liquid by the soil.
- LAND DEVELOPMENT
- 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 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, or a subdivision of land.
- LAND DISTURBANCE
- Any activity involving grading, tilling, digging, or filling or stripping of vegetation; or any other activity which causes land to be exposed to erosion. This includes the disturbance of site stone base below pavement materials.
- MAINTENANCE
- The upkeep necessary for efficient operation of physical properties.
- MUNICIPALITY
- The Township of Crescent.
- NRCS
- The National Resources Conservation Service (formerly the Soil Conservation Service), U.S. Department of Agriculture.
- OUTFALL
- The point or location at which stormwater leaves a site, which may include streams, storm sewers, swales or other well-defined natural or artificial drainage features, as well as areas of dispersed overland flow.
- OUTLET CONTROL STRUCTURE
- A structure designed to control the rate of stormwater runoff released from a detention system.
- PEAK DISCHARGE
- The maximum rate of flow of water at a given point and time resulting from a specified storm event.
- PEAK FLOW
- Maximum flow.
- PERFORMANCE STANDARD
- A standard which establishes an end result or outcome which is to be achieved, but does not prescribe specific means for achieving it.
- PERVIOUS
- A surface which permits the passage or entrance of water or other liquid.
- POINT OF INTEREST
- A point of hydraulic concern such as a bridge, culvert, or channel section, for which the rate of runoff is computed or measured.
- PROJECT SITE
- The specific area of land where any regulated activities in the municipality are planned, conducted, or maintained.
- QUALIFIED PERSON or QUALIFIED PROFESSIONAL
- Any person licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the work required by this chapter.
- RATE OF RUNOFF
- The instantaneous rate of water flow is usually expressed in cubic feet per second.
- REGULATED ACTIVITY
- Any earth disturbance activities or any activities that involve the alteration or development of land in a manner that may affect stormwater runoff.
- REGULATED EARTH DISTURBANCE ACTIVITY
- Earth disturbance activity of one acre or more. This includes earth disturbance on any portion of, part, or during any stage of, a larger common plan of development. This only includes road maintenance activities where pavement stone base is disturbed.
- RELEASE RATE PERCENTAGE
- The percentage of predevelopment peak rate of runoff from a watershed subbasin (as delineated in the watershed plan), which defines the allowable postdevelopment peak discharge from any development site in that subbasin.
- RETENTION POND
- A basin, usually enclosed by artificial dikes, that is used to retard stormwater runoff by temporarily storing the runoff for an extended period of time and releasing it at a predetermined rate. These are "wet ponds."
- RETURN PERIOD
- The average interval in years over which an event of a given magnitude can be expected to recur.
- RUNOFF
- The part of precipitation which flows over the land.
- RUNOFF CHARACTERISTICS
- The hydrologic, geologic, and land cover characteristics 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.
- SCS
- The Soil Conservation Service, U.S. Department of Agriculture.
- SEDIMENT
- 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.
- SMALL DEVELOPMENT
- Any subdivision or land development which results (or will result when fully constructed) in the creation of 5,000 or fewer square feet of impervious surface area.
- SOIL COVER COMPLEX METHOD
- A method of runoff computation developed by the SCS and utilized in its publication, "Urban Hydrology for Small Watersheds," Technical Release No. 55, SCS, June 1986 (or the most current edition).
- STATE WATER QUALITY REQUIREMENTS
- The regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code and the Clean Streams Law.[2]
- STORM SEWER
- A sewer that carries intercepted surface runoff, street water and other drainage, but excluding domestic sewage and domestic wastes.
- STORMWATER
- Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
- STORMWATER COLLECTION/CONVEYANCE SYSTEM
- 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, canals, channels, ditches, streams, culverts, streets, and pumping stations.
- STORMWATER MANAGEMENT PLAN
- The plan for managing stormwater runoff from a specific development site within the watershed.
- STORMWATER MANAGEMENT SITE PLAN
- The plan prepared by the developer or his representative indicating how stormwater runoff will be managed at the development site in accordance with this chapter. "Stormwater management site plan" will be designated as "SWM site plan" throughout this chapter.
- STORMWATER RUNOFF
- Water generated in a drainage basin resulting from snow melt or precipitation events.
- STORMWATER RUNOFF VOLUME
- The quantity of water resulting from a storm event, usually expressed in cubic feet, acre feet, or inches over acreage of the watershed.
- STREAM
- A watercourse, whether relatively permanent or nonrelatively permanent.
- SUBBASIN
- A portion of the watershed that has similar hydrologic characteristics and drains to a common point.
- SWALE
- A low-lying trench which gathers or carries surface water runoff.
- TIME OF CONCENTRATION
- The time period necessary from surface runoff to reach the outlet of a subarea from, hydraulically, the most remote point in the tributary drainage area.
- TOWNSHIP
- Crescent Township, Allegheny County, Pennsylvania.
- WATERCOURSE
- Any channel for conveyance of surface water having a defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
- WATERSHED
- The entire area drained by a river stream, or other body of water whether natural or man-made.
- WATERS OF THIS COMMONWEALTH
- Any and all rivers, streams, creeks, rivulets, impoundments, ditches, watercourses, storm sewers, lakes, dammed water, wetlands, ponds, springs, and all other bodies or channels of conveyance of surface and undergroundwater, or parts thereof, whether natural or artificial, within or on the boundaries of this Commonwealth.
A.
Stormwater runoff and design calculations shall be submitted to the
Township Engineer for review and to the Board of Commissioners for
approval with the application for preliminary and/or final approval
of a subdivision, land development, or any other activity that requires
stormwater management. Plans, profiles, cross sections, reports and/or
specifications showing complete construction details shall be submitted
with the application for final approval.
B.
The stormwater runoff and design calculations, plans and reports
shall be prepared, signed, and sealed by a Pennsylvania-registered
engineer with qualifications and experience in preparing stormwater
management plans.
C.
Additional analysis, calculations and design criteria may be required
for both on-site and off-site stormwater systems where it has been
determined by the Township Engineer that further study is necessary.
D.
Upon request by the Township Engineer, stormwater runoff calculations
shall be provided for: the outlet and inlet sides of all stormwater
drainage and storage facilities and structures; at points in a public
street with a change of grade; or where water from a proposed structure,
facility or vehicular way is to enter an existing public street, existing
storm sewer, existing drainage ditch or existing stormwater storage
facility.
A.
At the time of application, the Township shall determine if the development
qualifies as a "small development" and, therefore, is eligible for
a simplified stormwater plan submission. For the purposes of this
chapter, a small development is:
B.
A small development shall be exempt from the preparation of a stormwater
management plan as required by Section 445 of this chapter. However,
such developments shall provide safe management of stormwater in accordance
with the performance standards of this chapter and as approved by
the Township.
C.
Applications for small developments shall include a 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. Depending upon actual site conditions,
the number of lots proposed and similar considerations, the Township
shall determine if the plan must be prepared by a registered professional
engineer.
D.
The Township Engineer shall review and the Township shall approve
the proposed provisions for stormwater management for small developments.
Where the applicant is proposing to connect to an existing storm sewer,
the applicant's engineer shall determine 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 shall also
determine if the proposed development site is part of a larger parcel
or tract which was subject to any specific stormwater management controls
contained in a prior plan.
E.
For a parcel or tract of land held in 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.
A project cannot be phased to circumvent the stormwater requirements
by using the exemption for small developments.
A.
In conjunction with meeting the requirements of this chapter, the
applicant shall refer to and meet all conditions and requirements
set forth in the Township of Crescent's Municipal Separate Storm
Sewer System (MS4) Prohibited Discharge Ordinance.[1]
B.
In conjunction with meeting the requirements of the ordinance, the
applicant shall refer to and meet all conditions and requirements
set forth in the Township of Crescent's Total Maximum Daily Load
(TMDL) Plan as adopted and revised.
The stormwater management plan for all developments except small
developments, as defined in § 445.10, shall consist of the
following three components:
A.
Narrative report. The narrative report shall consist of a general
statement of the project giving the purpose and engineering assumptions
and calculations for control measures and facilities. The following
information shall be included:
1.
General description of the project.
2.
General description of accelerated runoff control plan.
3.
General description of erosion and sedimentation control plan.
4.
Expected project time schedule, including anticipated start and completion
dates.
5.
Location and watershed characteristics.
6.
Brief soils description.
7.
Hydraulic and hydrologic calculations, methodology and bases of design.
Computation of hydraulic and energy grade lines shall be included.
B.
Preliminary plan. The preliminary plan shall provide, and be accompanied
by, maps and other descriptive material indicating the feasibility
of the plan and showing the following:
1.
A key map showing the development site's location within the
designated watershed and watershed subsheds (consult watershed stormwater
plans for boundaries). On all site drawings, show the boundaries of
the watershed(s) and subarea(s) as they are located on the development
site and identify the watershed names and/or subshed numbers.
2.
Location of the one-hundred-year floodplain on the development site
based on the Crescent Township Flood Insurance Study Maps or a determination
by the applicant's engineer.
3.
An overlay showing soil types and boundaries within the development
site.
4.
The streets, storm sewers and other storm drains to be built, the
basis of their design, the outfall and outlet locations and elevations,
the receiving stream or channel and its high water elevation and the
functioning of the drains during high water conditions.
5.
The parts of the proposed parking area pavements, if any, which are
planned to be depressed to provide stormwater storage or conveyance.
A maximum of six inches depth of water may be ponded in a proposed
parking area, provided it is documented that such ponding does not
affect the health, safety, or welfare of those persons using the property.
6.
Existing streams and watercourses to be maintained and new channels
to be constructed, their locations, cross sections and profiles.
7.
Proposed culverts and bridges to be built, if any, their materials,
elevations, waterway openings and basis of design.
8.
Existing detention ponds and basins to be maintained, enlarged or
otherwise altered and new ponds or basins to be built and the basis
of their design.
9.
The approximate location and percentage of the total land area in
the development which will be covered by impervious surfaces after
construction is completed.
10.
The slope, type and size of all proposed and existing storm sewers
and other waterways.
11.
Existing contours at intervals of two feet must be provided, including
elevations, watercourses, trees and other significant natural features.
12.
All existing buildings, sewers, waterlines and other significant
man-made features.
13.
All natural features, including bodies of water (natural and artificial),
watercourses (permanent and intermittent), swales, wetlands and other
natural drainagecourses on the development site and those off site
which will be affected by runoff from the development.
14.
Approximate depth, shape, size and storage of any proposed retention
facility.
15.
One or more typical cross sections of all existing and proposed channels
or other open drainage facilities, showing the elevation of the existing
land and the proposed changes thereto, together with the high water
elevations expected from the one-hundred-year storm under the controlled
conditions called for by this chapter and the relationship of structures,
streets and other utilities.
16.
A site plan showing the property lines, dimensions of the site, and
location of existing and proposed structures, sewers, waterlines,
easements and rights-of-way.
17.
Certification of the registered professional engineer responsible
for preparation of the plan.
18.
A list of the permits and approvals relative to stormwater management
that will be required from other governmental agencies and anticipated
dates of submission and receipt. Copies of the applications must be
submitted to the Township.
C.
Final plan. Upon approval of the preliminary plan, the final plan
shall be submitted to the Township. The final plan shall provide all
descriptive material and maps previously submitted and required prior
to the final plan, in addition to the following items:
1.
All calculations, assumptions and criteria used in the design of
the storm sewer system, detention facilities and sediment and erosion
control operations. Hydraulic and energy grade lines shall be provided
for both the existing and proposed storm sewers to evaluate the storm
system.
2.
All plans and profiles of proposed storm sewers and open channels,
including horizontal and vertical controls, elevations, sizes, slopes
and materials. All drainage facilities shall be designed to contain
the energy grade line for the peak flow rate for the design storm
within the structures and pipes. Swales and channels shall provide
at least one foot of freeboard above the energy grade line.
3.
Locations, dimensions and design details required for the construction
of all facilities.
4.
For all detention basins, a plot or tabulation of storage volumes
with corresponding water surface elevations and basin outflow rates
for those water surface elevations.
5.
For all detention basins, design hydrographs of inflow and outflow
for the peak design flows from the site under natural and developed
conditions.
6.
A description of operation for all detention basins.
7.
Contours of the finished project site at intervals of two feet.
8.
The staging of earthmoving activities and program of operation, including
a schedule for the installation of all temporary and permanent stormwater
control measures and devices.
9.
All information relative to the design and operation of emergency
spillways.
10.
Emergency routing of outfall for stormwater runoff in the event of
failure of off-site drainage structures.
11.
When major control facilities, such as retention basins, requiring
a PA DEP permit, are planned, soil structures and characteristics
shall be investigated. Plans and data prepared by a licensed professional
engineer with experience and education in soil mechanics shall be
submitted. These submissions should consider and offer design solutions
for frost heave potential, shrink/swell potential, soil bearing strength,
water infiltration, soil settling characteristics, fill and backfilling
procedures and soil treatment techniques as required to protect the
improvements or structures.
12.
All erosion and sedimentation control measures, temporary, as well
as permanent, in sufficient detail to clearly indicate the effectiveness
of the plan.
13.
Project specifications relative to stormwater control, erosion and
sedimentation.
14.
Evidence that all on-site and off-site easements required to convey
runoff flow to an existing public drainage facility or a permanent
stream have been granted to the operating entity.
15.
Provide the information to conform with the requirements noted in
§§ 445.11, 445.12, 445.13 and 445.14.
16.
Provide a list of adjacent property owners within 200 feet of the
subject property and documentation that the adjacent property owners
have been notified of the proposed project.
D.
Maintenance plan. A maintenance plan establishing ownership and maintenance
responsibilities for all stormwater control facilities (identifying
the specific person or entity responsible) and detailing financial
requirements and sources of funding shall be submitted with the final
plan. Any legal agreements or covenants required to implement the
maintenance program shall be submitted. A maintenance schedule shall
be submitted in accordance with the Standardized Maintenance Schedule
in Appendix B.[2]
[2]
Editor's Note: Appendix B is included as an attachment
to this chapter.
A.
Stormwater management districts.
2.
One or more of these districts may be further divided into subareas
which have similar hydrological characteristics and drain to a common
point.
3.
The location and boundaries of the stormwater management districts
and subareas are adopted as overlay districts to the Township Zoning
Map and are shown on the Zoning Map and the watershed maps which are
available in the Township office.
B.
General 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 stormwater
management districts in the municipality:
1.
Any landowner and any person engaged in the alteration or development
of 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 is no greater
after development than prior to development activities; 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.
No discharge of toxic materials into any stormwater management system
will be permitted.
C.
Watershed standards for the Flaugherty Run Watershed District. The
stormwater performance standards contained in this section are intended
to implement the standards and criteria contained in the Flaugherty
Run Watershed Stormwater Management Plan, adopted and approved as
required by the Pennsylvania Storm Water Management Act. If there
is any discrepancy between the provisions of this chapter and the
standards and criteria of the plan, or if the watershed plan is subsequently
amended, then the standard criteria of the current watershed plan
shall govern.
D.
In the case of a development in which the total of the building and
paved surfaces on the site exceed 5,000 square feet, the developer
shall provide as part of the design a stormwater management narrative
signed and sealed by an engineer licensed in the Commonwealth of Pennsylvania.
The stormwater management narrative shall include an analysis of both
pre- and postdeveloped runoff conditions.
1.
For the analysis of redevelopment projects, 20% of the existing impervious
surface shall be considered meadow in good condition.
2.
Postdevelopment runoff rates after development shall not exceed the
predeveloped runoff rates including the reduction in impervious surface
required for redevelopment projects.
3.
The stormwater management plan for any development site with the
municipality shall consider all the stormwater runoff flowing over
the site, including runoff from upland and off-site areas.
4.
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.
A.
Design storms.
1.
Stormwater management detention/retention facilities within a development
shall be designed to handle the peak rate of runoff from one-year,
two-year, five-year, ten-year, twenty-five-year, fifty-year, and one-hundred-year
frequency storm events. Whenever the provisions of federal or state
law impose a greater design storm frequency, as for example, where
drainage systems cross highways, the stricter standards shall prevail.
2.
All stormwater retention/detention facilities shall be designed with
emergency overflow facilities for the one-hundred-year, twenty-four-hour
duration storm. Stormwater detention facilities shall drain within
24 to 72 hours from the end of the storm event.
3.
The stormwater volume required for all stormwater retention/detention
facilities shall be that volume necessary to handle runoff of a one-hundred-year
storm in any development, less that volume discharged during the same
storm period used to calculate the volume of rainfall, at the approved
release rate.
4.
The SCS Type II rainfall distribution shall be used for all analyses.
The design storm frequencies for the watershed are:
|
Design Storm
(year)
|
Rainfall Depth 24 Hours
(inches)
| |
|---|---|---|
|
1
|
1.97
| |
|
2
|
2.35
| |
|
5
|
2.88
| |
|
10
|
3.30
| |
|
25
|
3.90
| |
|
50
|
4.40
| |
|
100
|
5.20
|
B.
The stormwater management plan shall consider all of the stormwater
runoff flowing over the project site. Runoff calculations shall be
made to ensure that runoff from the fully developed upstream watershed
area (based on the Township's Comprehensive Land Use Plan) can
be accommodated by the pipes, drainage easements and watercourses,
etc., on the site.
C.
Joint development of control systems. Stormwater control systems
may be planned and constructed in coordination with two or more developments,
provided they are in compliance with the applicable provisions of
this chapter.
D.
Method of computation.
1.
All computations used in conjunction with the analysis and design
of stormwater management facilities shall be based on one or more
of the following methods:
2.
These methods for determining peak discharge shall be used to:
3.
These methods of runoff computation developed and used by the Soil
Conservation Service and other authorities are hereby adopted by the
Township.
4.
The use of the Basic Rational Method in estimating runoff may be
employed in the design of the storm sewer system within the development.
The storm sewer system shall be interpreted as the conduits, culverts,
inlets and appurtenant features for the conveying of stormwater to,
through or from a development site to the point of final discharge
or control facility. The Rational Method shall not be used in the
analysis of stormwater runoff from the development in its entirety
or in conjunction with the design of any retention/detention facilities
or other runoff control measures.
E.
Release of detained stormwater. The approved peak release rate of
stormwater from all retention/detention facilities for any storm event
shall be that which is experienced prior to development for the same
storm event up to and including the one-hundred-year storm. Therefore,
all retention/detention facilities shall provide staged release of
the one-, two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year
storms.
F.
Design of stormwater management facilities outlined in the plan requires
that runoff calculations be made for the site and areas which contribute
drainage to the site. These calculations should be based on land use,
time of concentration and other standard aspects of hydraulic analysis.
1.
Temporary control measures/facilities. Runoff calculations of the
site's condition during development will be used to size temporary
control measures.
2.
Permanent control measures/facilities. Permanent control measures/facilities
shall be designed to assure that the maximum rate of stormwater runoff
is no greater after development than prior to development activities,
utilizing the one-hundred-year storm as a basis for calculations.
Storm sewer systems may be designed for the twenty-five-year storm
provided that the runoff will naturally drain to the detention facility,
otherwise the storm sewer system must be designed for the one-hundred-year
storm event. Runoff calculations must be made to ensure that runoff
from the upstream watershed area can be accommodated by the pipes,
drainage easements, watercourses, etc., on the site as well as those
downstream of the site to a point of permanent stream discharge. Where
downstream facilities are not adequate to convey flow, reduced release
rates shall be considered to ensure no detrimental impact to the downstream
facilities shall occur as a result of the development.
G.
Runoff calculations shall also include complete hydrology and hydraulic
analysis of all downstream swales and pipe facilities to permanent
stream discharge point as well as all erosion control facilities.
Analysis shall include, but not limited to:
1.
Computation of hydraulic and energy grade lines. Velocities of flow,
slopes, capacity and roughness coefficient of conduits and grassed
waterways.
2.
Capacity of sediment basins and permanent holding ponds.
3.
All drainage facilities shall be designed to contain the energy grade
line for the peak flow rate for the design storm within the structures
a minimum of two feet below surface elevation. The hydraulic grade
must be within the pipe. Swales and channels shall provide at least
one foot of freeboard. Backwater effects of pipes discharging under
surcharge conditions shall be included.
H.
Flaugherty Run Watershed.
1.
Release-rate percentage.
(a)
Application. All subdivisions and land development activities
which result in an increase in the postdevelopment peak rate of stormwater
runoff from any outfall on the development site shall be subject to
release-rate percentage for the watershed subarea in which the site
(or outfall) is located. A listing of the release-rate percentage
for each subarea in the Flaugherty Run Watershed appears in Appendix
A of this chapter,[1] and the subareas are delineated on the watershed subarea
map in the watershed plan.
[1]
Editor's Note: Appendix A is on file in the Township
offices.
(b)
Definition. The release-rate percentage defines the percentage
of the predevelopment peak rate of runoff 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 postdevelopment
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.
(c)
Procedure for use. The steps that
must be followed to utilize the release-rate percentage for a particular
development site are as follows:
(2)
Compute the pre- and postdevelopment runoff hydrographs for each
stormwater outfall for the site, using the soil cover complex method
(SCS TR-55), for the one-, two-, five-, ten-, twenty-five-, fifty-,
and one-hundred-year design storms, applying no on-site detention
for stormwater management, but including any techniques to minimize
impervious surfaces and/or increase the time of concentration for
stormwater runoff flowing over the development site. If the postdevelopment
peak runoff rate is less than or equal to the predevelopment peak
runoff rate, then additional stormwater control shall not be required
at that outfall. If the postdevelopment peak runoff rate is greater
than the predevelopment value, then stormwater detention will be required
and proceed to Subsection H1c(3) below.
(3)
Multiply the subarea release-rate percentage by the predevelopment
rate of runoff from the development site to determine the maximum
allowable release rate from any detention facility for the one-, two-,
five-, ten-, twenty-five-, fifty-, and one-hundred-year design storm
events.
2.
No-harm evaluation.
(a)
An applicant may seek to extend the otherwise applicable subarea
release-rate percentage by performing the no-harm evaluation, which
requires an independent engineering analysis to demonstrate that other
reasonable options exist to protect downstream areas from harmful
storm runoff impacts.
(c)
The analysis for the no-harm evaluation shall be submitted to
the Township for review by the Township Engineer and approval of the
Township.
I.
Single-family lots.
1.
Retention facilities shall be constructed for all single-family lot
developments or single-family lots located in land developments which
for certain reasons cannot utilize the development's retention
systems. Retention facilities shall consist of gravel-filled sumps,
ponds, tanks or other approved facilities, sized in accordance with
standard details in the Township Construction Standards. Storage volumes
for roof areas greater than 5,000 square feet shall be calculated
using the methods outlined in § 445.14D.
2.
All stormwater retention facilities shall be located at least 10
feet from foundation walls in a location approved by the Township.
All pipe from roof drains to a point 10 feet from the structure shall
be a minimum Schedule 40 PVC pipe or approved equal.
J.
Easements.
1.
Easements for stormwater management facilities shall be required
to have a minimum width of 20 feet. Where a subdivision or land development
is, or will be, traversed by a watercourse, there shall be provided
a stormwater or drainage easement of a width sufficient for the purpose,
but not less than 20 feet. The stormwater detention facilities must
be provided within a drainage easement. An access easement must be
provided from the public right-of-way to the stormwater detention
facility with a minimum width of 20 feet.
2.
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.
(a)
Stormwater management easements are required for all areas used
for off-site stormwater control, unless a waiver is granted by the
municipality.
(b)
Stormwater management easements shall be provided by the property
owner if necessary for: 1) access for inspections and maintenance;
or 2) preservation of stormwater runoff conveyance, infiltration,
and detention areas and other BMPs, by persons other than the property
owner. The purpose of the easement shall be specified in any agreement
under Section 405.
(c)
Operation and management plans for stormwater management approved
pursuant to 25 Pa. Code 102 after the date of this chapter shall be
recorded as a restrictive deed covenant that runs with the land.
(d)
If a conservation easement is provided, the long-term ownership,
access, maintenance, and use restrictions must be identified on the
recording plan.
K.
Flood-prone areas. Land identified as flood-prone on maps issued
by the Federal Insurance Administration shall be subject to the regulations
of the National Flood Insurance Program and shall comply with the
provisions of the Township Zoning Ordinance governing floodplains.
L.
Stormwater detention facilities.
1.
If detention facilities are utilized for the development site, the
facility shall be designed such that the postdevelopment peak runoff
rates from the development site are controlled to those rates defined
by the subarea release-rate percentage or no-harm evaluation for the
two-, five-, ten-, twenty-five-, and one-hundred-year design storms;
except, however, where downstream flooding problems exist, the Township
may impose additional reduced release rate criteria.
2.
All detention facilities shall be equipped with multistage outlet
structures to provide discharge control for the two-, five-, ten-,
twenty-five-, and one-hundred-year storm frequencies. Provisions shall
also be made for safely passing the postdevelopment one-hundred-year
storm runoff flows without damaging (i.e., impairing the continued
function of) the facilities.
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 facility.
4.
Where detention facilities will be utilized, multiple-use facilities,
such as lakes, ball fields or similar recreation uses, are encouraged
wherever feasible.
5.
Other considerations which should be incorporated into the design
of the detention facilities include:
(a)
Inflow and outflow structures shall 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, shall be a design consideration.
(c)
Inflow and outflow structures, pumping stations and other structures
shall be protected and designed to minimize safety hazards.
(d)
The water depth of a storage pond shall be limited to that which
is safe for children. Otherwise, appropriately landscaped fencing
at least four feet in height shall be required.
(e)
Side slopes of storage ponds shall not exceed a ratio of 3:1
horizontal to vertical dimension.
(f)
Landscaping shall be provided for the facility which harmonizes
with the surrounding area.
(g)
All stormwater detention facilities shall be screened from view
of existing roads or streets located within the Township, which is
a minimum of six feet in height with sufficient access for maintenance
vehicles. The screening material must be approved by the Township.
Landscaping of the pond embankment shall not be permitted at any time.
(h)
The facility shall be located to facilitate maintenance, considering
the frequency and type of equipment that will be required.
(i)
The facility shall be equipped with an access road at least
eight feet wide and with a maximum of grade of 15%.
(j)
All pond outlet structures shall have suitable gaskets to prevent
leakage and piping of water through the pond embankment. All storm
pipe installed through the pond embankment must be constructed of
reinforced concrete pipe.
6.
A geotechnical investigation report for the construction of the stormwater
detention/retention and infiltration facilities must be provided including
design recommendation for embankment construction, interior and exterior
slopes, drainage swales and infiltration areas.
Stormwater culverts, bridges and similar structures serving
public streets, access driveways or other vehicular rights-of-way
shall be designed to support HS-20 loading and any other imposed loadings
necessary without structurally damaging the drainage system. Stormwater
culverts, bridges or other structures which do not serve vehicular
traffic shall be designed to support the necessary loading without
structurally damaging the pipe or affecting its capacity for drainage.
Said design shall be approved by the Township Engineer and shall comply
with the following requirements.
A.
Conduit size of culverts and other enclosed components of a stormwater
drainage system shall be based on computed hydrologic and hydraulic
data and computations shall be approved by the Township. The minimum
size of any enclosed structure to be maintained by the Township shall
be 15 inches in diameter. The minimum size of any enclosed structure
to be privately maintained shall be 15 inches in diameter, unless
the design calculations, approved by the Township, justify a lesser
size. In no case shall larger pipes/culverts be connected to smaller
pipes/culverts.
B.
The design of any enclosed drainagecourse shall provide a minimum
cleaning velocity of three feet per second. When the design provides
for a maximum velocity greater than 10 feet per second, the enclosed
components shall be lined or protected to prevent scour.
C.
The design of headwall and endwall structures for enclosed stormwater
facilities shall be approved by the Township and shall be in accordance
with the Township construction standards.
D.
Energy dissipaters shall be required at the outlet side of all enclosed
culverts or similar components and shall be designed in accordance
with the Township construction standards.
E.
The type of materials used for enclosed culverts and similar components
shall comply with the Township construction standards. No stormwater
facility shall be enclosed or covered over until the Township has
field reviewed the construction.
Stormwater management facilities shall be constructed in accordance
with the following minimum specifications:
A.
All workmanship and materials shall conform to the Township construction
standards. In addition, all workmanship and materials shall conform
to the latest edition of Penn DOT Form 408 and be supplied by manufacturers
or suppliers listed in Penn DOT's Bulletin 15.
B.
All connections to existing storm sewer pipes shall be made by construction
of a suitable junction box (inlet or manhole) to provide access for
cleanout. No blind connections shall be permitted.
C.
All pond outlet structure pipes shall have suitable gaskets to prevent
leakage and piping of water through the pond embankment.
D.
All pipe outlets shall discharge onto a stone rip-rap blanket to
prevent erosion of soil. Rip-rap will be sized considering pipe exit
velocities.
E.
Controls shall be installed at initial stages of earthmoving and
otherwise as outlined in the staging of earthmoving activities section
of the erosion and sedimentation control plan.
F.
The discharge of stormwater runoff shall be to a well-defined drainagecourse
which has a defined bed and bank. If stormwater runoff cannot be discharged
to a defined drainagecourse, documentation of written permission from
each downstream property owner shall be provided for all properties
between the source of discharge and the defined drainagecourse.
G.
All stormwater detention facilities shall be screened from view of
existing roads or streets located within the Township which is a minimum
of six feet in height with sufficient access for maintenance vehicles.
The screening materials must be approved by the Township. Landscaping
of the pond embankment shall not be permitted.
H.
Provide a geotechnical report for the construction of all stormwater
facilities including the following: stormwater detention basins and
the embankment; drainage swales; and infiltration areas.
Maintenance is an essential part of the successful functioning
of a stormwater management system and the following shall be required:
A.
Maintenance during development (See Appendix B).[1] Maintenance during development of a project shall be the
responsibility of the developer and/or landowner and shall usually
include, but shall not be limited to:
1.
Removal of silt from all debris basins, traps or other structures
or measures when 40% of capacity is filled with silt.
2.
Disposal of collected silt in a manner which will not adversely affect
the environment.
3.
Periodic maintenance of temporary control facilities such as replacement
of straw bale dikes, straw filters or similar measures.
4.
Establishment or re-establishment of vegetation by seeding and mulching
or sodding of scoured areas where vegetation has not been successfully
established. A developer or landowner retains this obligation as to
property he or she has developed or improved even if the proper season
for "seeding" occurs initially sometime after the project is otherwise
completed in whole or as to a particular phase.
5.
Installation of necessary controls sufficient to protect against
problems caused by storm events within design frequencies.
6.
Removal of all temporary measures upon completion of the project.
[1]
Editor's Note: Appendix B is included as an attachment
to this chapter.
B.
After acceptance of the Plan by the Township. In the event that the
Township accepts public improvements in the plan, except in cases
where an agreement between the developer and the Township has been
executed to the contrary, the maintenance shall be the responsibility
of the developer or his assigns and shall include, where necessary:
1.
Mowing to maintain adequate stands of grass and to control weeds.
Chemical weed control may be used if state and Township regulations
are met. Selection of seed mixtures shall reflect the type of maintenance
desired by the Township.
2.
Removal of silt from all permanent structures which trap silt or
sediment to keep this material from building up in grassed waterways
and other permanent structures, thereby reducing their capacity.
3.
Removal of trees and shrubs from pond embankments.
4.
Repair of animal burrows and removal of animals causing same.
C.
It shall be the responsibility of the developer to inspect all permanent
facilities to see that corrective action is taken where necessary.
D.
Stormwater facilities located on private property shall be maintained
by the landowner or his agent; however, this does not relieve the
landowner or his agent of the obligation to inspect his/her own facilities.
The Township reserves the right to enter upon private property to
make periodic reasonable inspections and to require the landowner
to take necessary corrective actions. An easement shall be recorded
granting access over private property to the stormwater facilities.
E.
The owner shall convey to the Township easements and/or rights-of-way
to assure access for periodic inspections by the Township and maintenance
if required.
F.
The owner shall keep on file with the Township the name, address
and telephone number of the person or company responsible for maintenance
activities; in the event of a change, new information will be submitted
to the Township within 10 days of the change.
G.
The owner shall establish any special maintenance funds or other
financing sources, in accordance with the approved maintenance plan.
H.
The owner shall pay the amount due to the Special Stormwater Facility
Maintenance Fund.
1.
Persons installing stormwater storage facilities will be required
to pay a specified amount to the Crescent Township Stormwater Facility
Maintenance Fund to help defray the costs of periodic inspections
and annual maintenance expenses. The amount of the deposit shall be
determined as follows:
(a)
If the storage facility is to be privately owned and maintained,
the deposit shall cover the cost of periodic inspections performed
by the Township for a period of 10 years, as estimated by the Township.
After that period of time, inspections will be performed by the Township
and billed directly to the owner.
(b)
If the storage facility is to be owned and maintained by the
Township, the deposit shall cover the estimated annual costs for maintenance
and inspections for 10 years, as estimated by the Township.
(c)
The amount of the deposit to the maintenance fund covering annual
inspection and maintenance costs shall be converted to present worth
of the annual series values. The Township Manager shall determine
the present-worth equivalents, which shall be subject to the final
approval of the Township Supervisors.
2.
If the storage facility is proposed, which also serves as a recreation
facility, such as a lake or ball field, the Township may reduce or
waive the amount of the maintenance fund based on the value of the
land for public recreation purposes.
3.
If at some future time any storage facility (whether publicly or
privately owned) is eliminated due to the installation of storm sewers
or another storage facility (i.e., a distributed storage facility),
the unused portion of the maintenance fund will be applied to the
cost of abandoning the facility and connecting to the storm sewer
system or other facility. Any amount of the deposit remaining after
the costs of abandonment are paid will be returned to the depositor.
I.
If the owner fails to maintain the stormwater control facilities,
following due notice by the Township to correct the problems, the
Township shall perform the necessary maintenance or corrective work.
The owner shall reimburse the Township for all costs.
J.
Additional items may be included in the maintenance 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 Township's Solicitor.
K.
Postconstruction stormwater record plan.
1.
Prior to issuance of an occupancy permit or utilization of the proposed
improvements the applicant must provide the Township a copy of a recorded
postconstructed stormwater management plan and the proof of recording
for any project containing stormwater management facilities including
storm sewers and BMPs.
2.
The owner shall provide a plan in digital format, on state plain
coordinates, identifying the location of all stormwater management
BMPs.
A.
The Township or a designated representative shall field review the
construction of the temporary and permanent stormwater management
facilities for the development site. The permittee shall notify the
Township 48 hours in advance of the completion of the following key
development phases:
1.
At the completion of the 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 improvement and ground
covers.
3.
During construction of the permanent stormwater facilities at such
times as specified by the Township.
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 field reviewed by the Township Engineer and approved
by the Township in writing. If there are deficiencies in any phase,
the Township shall issue a written description of the required corrections
and stipulate the time by which the corrections must be made.
C.
If during construction the contractor or permittee identifies any
site conditions, such as subsurface soil conditions or alterations
in surface or subsurface drainage, which could affect the feasibility
of the approved stormwater facilities, said person must notify the
Township within 24 hours of the discovery of such condition and request
a field review by the Township. The Township 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 where other special site conditions exist,
the Township may require special precautions, such as soil tests and
core borings, full-time resident project representative services and/or
similar measures. All costs of any such measures shall be borne by
the permittee.
Erosion and sediment control.
A.
No regulated earth disturbance activities within the Township shall
commence until approval by the Township of an erosion and sediment
control plan for construction activities.
B.
The Pennsylvania Department of Environmental Protection (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.
In addition, under 25 Pa. Code Chapter 92,[1]a DEP "NPDES Construction Activities" permit is required
for any earth disturbance one acre of 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 (hereinafter collectively
referred to as "regulated earth disturbance activities"). This includes
earth disturbance on any portion of, part of, or during any stage
of, a larger common plan of development.
[1]
Editor's Note: Chapter 92 of Title 25 of the Pennsylvania
Code was reserved 10-8-2010, effective 10-9-2010. It was replaced
by Chapter 92a, National Pollutant Discharge Elimination System (NPDES)
Permitting, Monitoring and Compliance.
D.
Evidence of any necessary permit(s) for regulated earth disturbance activities from the appropriate DEP regional office or Allegheny 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 Subsection A.
E.
A copy of the erosion and sediment control plan and any required
permit, as required by DEP regulations, shall be available at the
project site at all times.
Postconstruction runoff control requirements.
A.
No regulated earth disturbance activities within the Township shall
commence until approval by the Township of a plan which demonstrates
compliance with state water quality requirements after construction
is complete.
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 postconstruction stormwater impacts from regulated earth
disturbance activities, state water quality requirements can be met
by BMPs, including site design, which provide for replication of preconstruction
stormwater infiltration and runoff conditions, so that postconstruction
stormwater discharges do not degrade the physical, chemical or biological
characteristics of the receiving waters. As described in the DEP Comprehensive
Stormwater Management Policy (#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 postconstruction stormwater discharges to prevent physical degradation
of receiving waters (e.g., from scouring and erosion).
D.
DEP has regulations that require municipalities to ensure design,
implementation and maintenance of best management practices ("BMPs")
that control runoff from new development and redevelopment (hereinafter
"development") after regulated earth disturbance activities are complete.
These requirements include the need to implement postconstruction
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 Allegheny 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 Subsection A.
B.
Enforcement.
1.
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 require without limitation:
(a)
The performance of monitoring, analyses, and reporting;
(b)
The elimination of prohibited discharges;
(c)
Cessation of any violating discharges, practices, or operations;
(d)
The abatement or remediation of stormwater pollution or contamination
hazards and the restoration of any affected property;
(e)
Payment of a fine to cover administrative and remediation costs;
(f)
The implementation of stormwater BMPs; and
(g)
Operation and maintenance of stormwater BMPs.
2.
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.
C.
Inspection.
1.
DEP or its designees (e.g., County Conservation Districts) normally
ensure compliance with any permits issued, including those for stormwater
management. In addition to DEP compliance programs, the municipality
or its designee may inspect all phases of the construction, operations,
maintenance and any other implementation of stormwater BMPs.
2.
During any stage of the regulated earth disturbance activities, if
the municipality or its designee determines that any BMPs are not
being implemented in accordance with this chapter, the municipality
may suspend or revoke any existing permits or other approvals until
the deficiencies are corrected.
D.
Right of entry.
1.
BMP owners and operators shall allow persons working on behalf of
the municipality ready access to all parts of the premises for the
purposes of determining compliance with this chapter.
2.
Persons working on behalf of the municipality shall have the right
to temporarily locate on any BMP in the municipality such devices
as are necessary to conduct monitoring and/or sampling of the discharges
from such BMP.
3.
Unreasonable delays in allowing the municipality access to a BMP
is a violation of this chapter.
E.
Suspension and revocation of permits and approvals. Any building,
land development or other permit or approval for regulated earth disturbance
activities issued by the Township may be suspended or revoked by the
governing body 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 or property of
others.
F.
Penalties.
1.
Any person violating the provisions of this chapter shall be guilty
of a misdemeanor, and upon conviction shall be subject to a fine of
not more than $1,000 for each violation, recoverable with costs, or
imprisonment of not more than 30 days, or both. Each day that the
violation continues shall be a separate offense.
2.
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.
G.
Prohibitions.
1.
Prohibited discharges.
(a)
Upon notice provided by the municipality under Subsection C, the discharger will have a reasonable time, as determined by the municipality, to cease the discharge consistent with the degree of pollution caused by the discharge.
(b)
Nothing in this section shall affect a discharger's responsibilities
under state law.
A.
The stormwater management plan for the development site shall establish
responsibilities for the continuing operation and maintenance of all
proposed stormwater control facilities. The proposed maintenance plan
should be consistent with the general maintenance policies stated
in this chapter, the Township Stormwater Management Ordinance, and
also consistent with the following principles:
1.
If a development consists of structures or lots which are to be separately
owned and in which streets, sewers and other public improvements are
to be dedicated to the Township, stormwater control facilities should
also be dedicated to and maintained by the Township.
2.
If a development site is to be maintained in single ownership or
if sewers and other public improvements are to be privately owned
and maintained, then the ownership and maintenance of stormwater control
facilities should be the responsibility of the owner or private management
entity.
B.
The Township Council shall make the final determination on the continuing
maintenance responsibilities as part of the final application review
based on the recommendation of the Planning Commission. The Council
reserves the right to accept or reject the ownership and operating
responsibility of any or all of the stormwater management controls.
C.
Alteration of BMPs.
1.
No person shall modify, remove, fill, landscape or alter any existing
stormwater BMP, unless it is part of an approved maintenance program,
without the written approval of the municipality.
2.
No person shall place any structure, fill, landscaping or vegetation
into a stormwater BMP or within a drainage easement, which would limit
or alter the functioning of the BMP, without the written approval
of the municipality.