[Ord. No. 1528,[1] 9-26-2022]
(a) 
The Town of McCandless finds that:
(1) 
Inadequate management of accelerated runoff of stormwater resulting from development throughout a watershed increases flows and velocities, contributes to erosion and sedimentation, overtaxes the carrying capacity of streams and storm sewers, greatly 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 non-point-source pollution of water resources.
(2) 
A comprehensive program of stormwater management, including reasonable regulation of development and activities causing accelerated runoff, is fundamental to the public health, safety, and welfare and the protection of people of the commonwealth, their resources, and the environment.
(3) 
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.
(4) 
Federal and state regulations require certain municipalities to implement a program of stormwater controls. These municipalities are required to obtain a permit for stormwater discharges from their separate storm sewer systems under the National Pollutant Discharge Elimination System (NPDES).
(b) 
In order to protect the health, safety, and general welfare of the residents of the Town of McCandless, as well as to protect, sustain, and enhance the surface water and groundwater resources of the Town, drainage and stormwater management practices shall be utilized as directed herein to achieve the following goals and objectives:
(1) 
Accommodate site development and redevelopment in a manner that protects public safety and that is consistent with (or reestablishes) the natural hydrologic characteristics of each watershed and sustains groundwater recharge, stream baseflows, stable stream channel (geomorphology) conditions, the carrying capacity of streams and their floodplains, groundwater and surface water quality, and aquatic living resources and their habitats.
(2) 
Reduce and minimize the volume of stormwater generated.
(3) 
Protect natural infiltration and groundwater recharge rates in order to sustain groundwater supplies and stream baseflows.
(4) 
Maintain runoff characteristics of the site after completion of development that are consistent with the carrying capacity and stable channel conditions of the receiving streams.
(5) 
Protect water quality by removing and/or treating pollutants prior to discharge to groundwaters and surface waters throughout the Town, and protect, restore, and maintain the chemical, physical, and biological quality of groundwaters and surface waters.
(6) 
Protect in-stream channels and geomorphology conditions of the receiving streams, protect their flood-carrying capacity and aquatic habitats, and reduce in-stream aggradation, degradation, and scour.
(7) 
Reduce flooding impacts and prevent a significant increase in surface runoff rates and volumes, predevelopment to post-development, which could worsen flooding downstream in the watershed, enlarge floodplains, erode stream banks, and create other flood-related health-welfare-property losses; in general, preserve and restore the natural flood-carrying capacity of streams and their floodplains.
(8) 
Protect adjacent lands from adverse impacts of direct stormwater discharges.
(9) 
Ensure effective long-term operation and maintenance of all permanent stormwater management facilities.
(10) 
Maintain natural drainage patterns and encourage the use of natural drainage systems.
(11) 
Treat and release stormwater as close to the source of runoff as possible using a minimum of structures and maximizing reliance on natural processes.
(12) 
Maintain the existing water balance in all watersheds, sub-watersheds, and streams in the Town and protect and/or restore natural hydrologic characteristics and habitats wherever possible throughout the watershed systems.
(13) 
Address certain requirements of the municipal separate storm sewer system (MS4) National Pollutant Discharge Elimination System (NPDES) Phase II Stormwater Regulations.
(14) 
Reduce the impacts of runoff from existing developed sites undergoing redevelopment while encouraging development and redevelopment in urban areas and areas designated for growth.
(15) 
Meet water quality requirements under state law, including regulations at 25 Pa. Code Chapter 93.4a, to protect and maintain existing uses and maintain the level of water quality to support those uses in all streams and to protect and maintain water quality in special-protection streams.
(16) 
Prevent scour and erosion of stream banks and streambeds.
[1]
Editor's Note: This ordinance also repealed former Ch. 913, Stormwater Management, adopted 11-26-2018 by Ord. No. 1481.
[Ord. No. 1528, 9-26-2022]
(a) 
Primary authority. The Town of McCandless is empowered to regulate these activities by the authority of 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.
(b) 
Secondary authority. The Town also is empowered to regulate land use activities that affect stormwater 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.
[Ord. No. 1528, 9-26-2022]
The standards contained herein shall apply to all regulated activities within the Town. In addition, all local, county and state erosion and sedimentation control approvals must be in place to proceed with any regulated activity.
(a) 
Activities regulated by this article include, but are not limited to, the following:
(1) 
Land development and redevelopment.
(2) 
Subdivision.
(3) 
Construction of new or additional impervious or semipervious surfaces (driveways, parking lots, etc.).
(4) 
Construction of new buildings or additions to existing buildings.
(5) 
Diversion or piping of any natural or man-made stream channel.
(6) 
Installation of stormwater management facilities or appurtenances thereto.
(7) 
Any earth disturbances or any activities that involve the alteration or development of land or removal of trees and vegetation in a manner that may affect post-construction stormwater runoff.
(8) 
All stormwater runoff entering the Town's separate storm sewer system.
(b) 
Redevelopments shall conform to the requirements contained in § 913.14(c)(3) when more than a 2,000-square-foot area of an existing facility is reconstructed following the demolition or partial demolition of that facility. The area determination shall be made using the footprint of the area being reconstructed, including all impervious and semi-impervious surfaces proposed in the reconstructed area and including the increased area of any parking lot required to support the reconstructed facility. The area of the parking lot required to support the reconstructed facility shall be determined using the Town Zoning Ordinance[1] requirements for parking. The presence of existing impervious or semi-impervious surfaces in predeveloped conditions does not justify a waiver of this provision.
[1]
Editor's Note: See Part 13, Planning and Zoning Code.
[Ord. No. 1528, 9-26-2022]
Any permit or authorization issued or approval based on false, misleading, or erroneous information provided by an applicant is void without the necessity of any proceedings for revocation. Any work undertaken or use established pursuant to such permit or other authorization is unlawful. No action may be taken by a board, agency or employee of the municipality purporting to validate such a violation.
[Ord. No. 1528, 9-26-2022]
(a) 
If the Town determines that any requirement under this article cannot be achieved for a particular regulated activity, Town Council may, after an evaluation of alternatives, approve measures other than those in this article, subject to § 913.05(b) and (c). The request for a waiver or modification shall originate with the landowner, shall be in writing, and shall accompany the stormwater management site plan submission to the Town. The request shall provide the facts on which the request is based, the provision(s) of the ordinance involved and the proposed modification. The Town Engineer shall review the request to determine if it meets the requirements of this article, including § 913.05(b) and (c), and issue a recommendation to Town Council. If acceptable to Town Council and the regulated stormwater activity involving earth disturbance is less than one acre, Town Council may grant the waiver or modification.
(b) 
Waivers or modifications of the requirements of this article may be approved by Town Council if enforcement will exact undue hardship because of unique physical circumstances or preexisting site conditions peculiar to the land in question, provided that the modifications will not be contrary or detrimental to the public interest and will achieve the intended outcome, and that the purpose of the article is preserved. Hardship must be due to such unique physical circumstances or preexisting site conditions and not the circumstances or conditions generally created by the provisions of this article, and there is no possibility that the property can be developed in strict conformity with the provisions of this article. Cost or financial burden shall not be considered a hardship. Hardship cannot have been created by the landowner or developer. Modification shall not substantially or permanently impair the appropriate use or development of adjacent property. Modification may be considered if an alternative standard or approach will provide equal or better achievement of the purpose of this article.
(c) 
No waiver or modification of any regulated stormwater activity involving earth disturbance greater than or equal to one acre may be granted by Town Council unless that section is approved in advance by the Department of Environmental Protection (DEP).
[Ord. No. 1528, 9-26-2022]
The following activities may be exempt from on-site stormwater runoff control, provided that they follow all other applicable requirements of this section. An exemption shall apply only to the requirement for on-site stormwater facilities and the preparation of a stormwater management plan. All other stormwater management design elements, such as a storm sewer system, road culverts, erosion and sedimentation control, and runoff quality, shall be required. All exemption requests must be filed with the Zoning Officer and approved by the Engineer.
(a) 
Regulated activities smaller than 400 square feet of impervious area are exempt from the requirements of this article to implement SWM BMPs, unless the activity is found to be a significant contributor to pollution of the waters of this commonwealth.
(b) 
Small project exemption.
(1) 
Table 1 and Table 2 present stormwater management requirements for small projects. For projects that propose additional impervious area or earth disturbance to a parcel, the total proposed impervious area and total proposed earth disturbance on the parcel is subject to the requirements of this article. Impervious area is described in § 913.07.
Table 1
Stormwater Management Requirements for Increase in Impervious Area
Number
Square Feet of Proposed Impervious Surface
Stormwater Management Requirement
1
Less than 400
No requirements if there were no previous impervious surface additions
2
400 to 2,500
(small project)
Capture and detain the first 2 inches of any storm event
(Appendix F)[1]
3
More than 2,500
Comply with requirement of this article
Table 2
Stormwater Management Requirements for Proposed Earth Disturbance
Number
Square Feet of Proposed Earth Disturbance
Stormwater Management Requirement
1
Less than 10,890
No requirements if there were no previous impervious surface additions
2
10,890 to 43,559
(small project)
Capture and detain the first 2 inches of any storm event (Appendix F)[2]
3
More than 43,559
Comply with requirements of this article
[1]
Editor's Note: Appendix F is included as an attachment to this article.
[2]
Editor's Note: Appendix F is included as an attachment to this article.
(2) 
An erosion and sedimentation (E&S) control plan must be submitted to the Town for review and/or approved by the Allegheny County Conservation District (ACCD), as deemed necessary.
(3) 
An approved E&S plan is required to be on-site.
(c) 
Emergency exemption. Emergency maintenance work performed for the protection of public health, safety and welfare may be exempted from the requirements in this article to obtain approval for a stormwater management plan before commencement of the activity; however, a written description of the scope and extent of any emergency work performed shall be submitted to the Town within two calendar days of the commencement of the activity. If the Town finds that the work is not an emergency, then the work shall cease immediately and may not resume until a written stormwater management plan is submitted and approved.
(d) 
Maintenance exemption: any maintenance to an existing stormwater management system made in accordance with plans and specifications approved by the Engineer or the Town.
(e) 
Gardening: use of land for gardening for home consumption.
(f) 
Agricultural activities: agriculture, when operated in accordance with a conservation plan, nutrient management plan or erosion and sedimentation control plan approved by the Allegheny County Conservation District, including activities such as growing crops, rotating crops, tilling of soil and grazing animals. Installation of new or expansion of existing farmsteads, animal housing, waste storage and production areas having impervious surfaces that result in a net increase in impervious surface of less than 1,000 square feet are exempt from the requirement to submit a written stormwater management plan.
(g) 
Forest management: forest management operations which are consistent with a sound forest management plan as filed with the Town Land Use Administrator and which follow the Pennsylvania Department of Environmental Protection's management practices contained in its publication Soil Erosion and Sedimentation Control Guidelines for Forestry. Such operations are required to have an erosion and sedimentation control plan.
[Ord. No. 1528, 9-26-2022]
As used in this article, the following terms shall have the meanings indicated:
AASHTO
American Association of State Highway and Transportation Officials. The website home page for AASHTO is http://transportation1.org/aashtonew/.
ACCD
Allegheny County Conservation District.
ACHD
Allegheny County Health Department.
ACT 167
The Storm Water Management Act (Act of October 4, 1978, P.L. 864, No. 167; 32 P.S. §§ 680.1 through 680.17, as amended).
ACT 167 STORMWATER MANAGEMENT PLAN
The Girty's Run, Lowries Run, and Pine Creek Stormwater Management Plan for managing stormwater runoff adopted by the County of Allegheny as required by the Act of October 4, 1978, P.L. 864 (Act 167), as amended, and known as the "Storm Water Management Act."
AGRICULTURAL ACTIVITY
The work of producing crops, including tillage, land clearing, plowing, disking, harrowing, planting, and 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, developer or other person who has filed an application for approval to engage in any regulated activity at a project site in the Town.
AQUIFER
A geologic formation, group of formations, or part of a formation that contains sufficient saturated, permeable material to yield useful quantities of groundwater to wells and springs.
ATTENUATE
To reduce the magnitude of the flow rate by increasing the time it takes to release a specified volume of runoff (for example, the one-year, twenty-four-hour storm event). Attenuation is a method of reducing the peak flow rates for post-development compared to the peak flow rates in predevelopment.
BASEFLOW
The portion of stream discharge derived from groundwater; the sustained discharge that does not result from direct runoff or from water diversions, reservoir releases, piped discharges, or other human activities.
BEST MANAGEMENT PRACTICE (BMP)
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 article. Stormwater BMPs are commonly grouped into one of two broad categories or measures: structural or nonstructural. In this article, "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.
CFS
Cubic feet per second.
CHANNEL
A natural or artificial watercourse that conveys, continuously or periodically, flowing water.
CONCENTRATED STORM RUNOFF
Surface runoff from rainfall events which converges and flows primarily through water-conveyance features such as swales, gullies, waterways, channels or storm sewers and which exceeds the maximum specified flow rates of filters or perimeter controls intended to control sheet flow.
CONSERVATION DESIGN
A series of holistic land development design practices that maximize protection of key land and environmental resources, preserve significant concentrations of open space and greenways, evaluate and maintain site hydrology, and ensure flexibility in development design to meet community needs for complementary and aesthetically pleasing development. Conservation design encompasses the following objectives: conservation/enhancement of natural resources, wildlife habitat, biodiversity corridors and greenways (interconnected open space); minimization of environmental impact resulting from a change in land use (minimum disturbance, minimum maintenance); maintenance of a balanced water budget by making use of site characteristics and infiltration; incorporation of unique natural, scenic and historic site features into the configuration of the development; preservation of the integral characteristics of the site as viewed from adjoining roads; and reduction in maintenance required for stormwater management practices. Such objectives can be met on a site through an integrated development process that respects natural site conditions and attempts, to the maximum extent possible, to replicate or improve the natural hydrology of a site.
CONSERVATION DISTRICT
A conservation district, as defined in Section 3(c) of the Conservation District Law [3 P.S. § 851(c)], that has the authority under a delegation agreement executed with the DEP to administer and enforce all or a portion of the regulations promulgated under 25 Pa. Code Chapter 102.
DEP
The Pennsylvania Department of Environmental Protection.
DESIGN STORM
The magnitude and temporal distribution of precipitation from a storm event, measured in probability of occurrence (e.g., a five-year storm) and duration (e.g., 24 hours), used in the design and evaluation of stormwater management systems. Also see "return period."
DETENTION BASIN
An impoundment designed to collect and retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. Detention basins are designed to drain completely shortly after any given rainfall event and are dry until the next rainfall event.
DETENTION or TO DETAIN
The prevention of, or to prevent, the discharge, directly or indirectly, of a given volume and rate of stormwater runoff into surface waters by temporary storage.
DEVELOPMENT SITE (SITE)
See "project site."
DISCHARGE
(a) 
To release water from a project, site, aquifer, drainage basin or other point of interest (verb).
(b) 
The rate and volume of flow of water such as in a stream, generally expressed in cubic feet per second (volume per unit of time) (noun).
DISTURBED AREA
An unstabilized land area where an earth disturbance is occurring or has occurred.
DITCH
An artificial waterway for irrigation or stormwater conveyance.
DRAINAGE AREA
That land area contributing runoff to a single point and that is enclosed by a ridgeline.
DRAINAGE SYSTEM
All facilities and natural features used for the movement of stormwater through and from a drainage area, including, but not limited to, any and all of the following: conduits, pipes and appurtenant features, channels, ditches, flumes, culverts, streets, swales, gutters, as well as all watercourses, water bodies and wetlands.
EARTH DISTURBANCE
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.
EASEMENT
A right of use of a specified portion of land of another for a specified purpose.
ENGINEER
A professional engineer duly appointed as the Municipal Engineer and/or the Stormwater Management Engineer for the Town.
EPA
Environmental Protection Agency.
EROSION
The wearing away of land surface by water or wind which occurs naturally from weather or runoff but is often intensified by human activity.
EXISTING CONDITION
The dominant land cover during the five-year period immediately preceding a proposed regulated activity.
FACILITY
Any residential or commercial building or impervious or semi-impervious surface.
FEMA
Federal Emergency Management Agency.
FIRST-ORDER STREAM
The uppermost perennial tributary in a watershed that has not yet confluenced with another perennial stream. The confluence of two first-order streams forms a second-order stream.
FLOODPLAIN
Any land area susceptible to inundation by water from any natural source or delineated by applicable Federal Emergency Management Agency (FEMA) maps and studies as being a special flood hazard area.
FLOODWAY
The channel of the watercourse and those portions of the adjoining floodplains that are reasonably required to carry and discharge the one-percent-annual-chance flood (100-year flood). Unless otherwise specified, the boundary of the floodway is as indicated on maps and flood insurance studies provided by FEMA. In an area where no FEMA maps or studies have defined the boundary of the floodway, it is assumed, absent evidence to the contrary, that the floodway extends 50 feet from the top of the bank of the stream into the floodplain parallel to the stream.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forestland. These include timber inventory and preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation and reforestation.
FREEBOARD
The difference between the elevation of the design flow in the emergency spillway (usually the 100-year peak elevation) and the top elevation of the settled basin embankment (that is, top of berm). The minimum freeboard shall be one foot.
GROUNDWATER
Water that occurs in the subsurface and fills or saturates the porous openings, fractures and fissures of underground soils and rock units.
HOTSPOT
An area where land use or activities generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater.
HYDROGRAPH
A graph of discharge versus time for a selected point in the drainage system.
HYDROLOGIC SOIL GROUP (HSG)
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 Natural Resources Conservation Service (NRCS) of the U.S. Department of Agriculture 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.
HYDROLOGY
The study of the properties, distribution, circulation, and effects of water on the earth's surface, soil and atmosphere.
IMPERVIOUS COVER
See "impervious surface."
IMPERVIOUS SURFACE (IMPERVIOUS AREA)
A surface that prevents the infiltration of water into the ground. Impervious surfaces (or areas) shall include, but not be limited to: roofs; additional indoor living spaces, patios, garages, storage sheds and similar structures; and any new streets or sidewalks. Decks, parking areas, and driveway areas are counted as impervious areas if they directly prevent infiltration. Aggregate areas shall be considered impervious in post-developed conditions.
INFILTRATION
Movement of surface water into the soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolates downward to recharge groundwater.
INTENSITY
The depth of accumulated rainfall per unit of time.
INTERMITTENT STREAM
A defined channel in which surface water is absent during a portion of the year, as groundwater levels drop below the channel bottom.
KARST
A type of topography or landscape characterized by surface depressions, sinkholes, rock pinnacles/uneven bedrock surface, underground drainage, and caves. Karst is formed on carbonate rocks, such as limestone or dolomite.
LAND DEVELOPMENT (DEVELOPMENT)
Inclusive of any or all of the following meanings:
(a) 
The improvement of one lot or two or more contiguous lots, tracts, or parcels of land for any purpose involving:
(1) 
A group of two or more buildings; or
(2) 
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.
(b) 
Any subdivision of land.
(c) 
Development in accordance with Section 503 of the Pennsylvania Municipalities Planning Code.[1]
LEVEL SPREADER
A low earthen berm constructed perpendicular to the direction of slope and extending across the width of the slope for the purpose of intercepting surface runoff and spreading it behind the berm to enhance infiltration and reduce erosion and runoff from the slope. The purpose of a level spreader is to prevent concentrated, erosive flows from occurring and to spread out stormwater runoff uniformly over the ground as sheet flow.
LOADING
The total amount (generally measured in pounds or kilograms per acre per year) of material (sediment, nutrients, oxygen-demanding material, or other chemicals or compounds) brought into a lake, stream or water body by inflowing streams, runoff, direct discharge through pipes, groundwater, the air (aerial or atmospheric deposition) and other sources over a specific period of time (often annually).
LOW-IMPACT DEVELOPMENT (LID)
Site design approaches and small-scale stormwater management practices that promote the use of natural systems for infiltration, evapotranspiration, and reuse of rainwater. LID can be applied to new development, urban retrofits, and revitalization projects. LID utilizes design techniques that infiltrate, filter, evaporate, and store runoff close to its source. Rather than rely on costly large-scale conveyance and treatment systems, LID addresses stormwater through a variety of small, cost-effective landscape features located on-site.
MAINTENANCE
The action taken to restore or preserve the as-built functional design of any facility or system.
MEADOW CONDITION
A natural ground cover with less than one viable tree of a DBH of six inches or greater per 1,500 square feet within 10 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.
MS4
Municipal separate storm sewer system.
MUNICIPALITY
The Town of McCandless.
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)
Created in 1972 under the Clean Water Act to authorize discharges to local receiving waters only pursuant to governmental permits, in an effort to reduce point-source and non-point-source pollutants.
NEW DEVELOPMENT
Any activity regulated by this article that is not considered a redevelopment as defined in this article.
NOAA
National Oceanic and Atmospheric Administration.
NONSTRUCTURAL STORMWATER MANAGEMENT PRACTICES
Passive site design approaches or regulatory approaches that positively impact water quality and reduce or minimize the generation of stormwater runoff without requiring the construction of specific or discrete stormwater management control structures.
NRCS
Natural Resources Conservation Service.
OPEN CHANNEL
Any natural or man-made watercourse or conduit in which water flows with a free surface.
OPEN VEGETATED CHANNEL
Also known as "swales," "grass channels," and "biofilters." These systems are used for the conveyance, retention, infiltration, and filtration of stormwater runoff.
PACD
Pennsylvania Association of Conservation Districts.
PADEP
Pennsylvania Department of Environmental Protection.
PASTURE CONDITION
A ground cover of grassland or range with continuous forage for grazing and greater than 75% ground cover and lightly or only occasionally grazed; a cover condition for which the Soil Conservation Service curve numbers have been assigned or to which equivalent Rational Method runoff coefficients have been assigned.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specific storm event.
PENNDOT
Pennsylvania Department of Transportation.
PERCOLATION RATE
The rate of movement of water under hydrostatic pressure through interstices of rock or soil. For stormwater analysis, it is typically measured as a distance per unit of time (e.g., inches per hour).
PERVIOUS AREA
Any area not defined as impervious.
PREDEVELOPMENT ASSUMPTION
The ground cover assumption used when analyzing the stormwater runoff characteristics of a drainage area prior to the proposed development.
PROJECT SITE
The specific area of land where any regulated activities in the Town are planned, conducted, or maintained.
QUALIFIED PROFESSIONAL
Any person licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the work required by this article.
RAINFALL INTENSITY
The depth of accumulated rainfall per unit of time.
RATE
Volume per unit of time.
RECEIVING WATERS
Any water bodies, watercourses, or wetlands into which surface waters flow.
RECHARGE
The replenishment of groundwater through the infiltration of rainfall, other surface waters, or land application of water or treated wastewater.
REDEVELOPMENT
An existing developed property, as of or after the date of adoption of this article, that is proposed for reconstruction involving the demolition or partial demolition of the property.
REGULATED ACTIVITIES
Any earth disturbances or any activities that involve the alteration or development of land in a manner that may affect post-construction stormwater runoff.
REGULATED EARTH DISTURBANCE ACTIVITY
Activity involving earth disturbance subject to regulation under 25 Pa. Code Chapter 92, Chapter 102, or the Clean Streams Law.[2]
RELEASE RATE DISTRICT
A watershed or portion of a watershed for which a release rate has been established by an adopted Act 167 Stormwater Management Plan.
RELEASE RATE PERCENTAGE
The percentage of predevelopment peak rate of runoff from a watershed subarea (as delineated in the Act 167 watershed plan), which defines the allowable post-development peak discharge from any development site in that subarea.
RETENTION BASIN
An impoundment designed to collect and retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. Retention basins may also be designed to permanently retain additional stormwater runoff. Retention basins are designed to retain a permanent pool of water during dry weather.
RETENTION or TO RETAIN
The prevention of direct discharge of stormwater runoff into receiving waters or water bodies by temporary or permanent containment in a pond or depression; examples include systems which discharge by percolation to groundwater, exfiltration, and/or evaporation processes and which generally have residence times of less than three days.
RETURN PERIOD
The average interval, in years, within which a storm event of a given magnitude can be expected to occur one time. For example, the twenty-five-year return period rainfall would be expected to occur on average once every 25 years.
RIPARIAN
Pertaining to anything connected with or immediately adjacent to the banks of a stream or other body of water.
RIPARIAN BUFFER
An area of land adjacent to a body of water and managed to maintain the integrity of stream channels and shorelines to:
(a) 
Reduce the impact of upland sources of pollution by trapping, filtering and converting sediments, nutrients and other chemicals; and
(b) 
Supply food, cover and thermal protection to fish and other wildlife.
RUNOFF
See "stormwater."
SCS
Soil Conservation Service.
SEDIMENT
Fragmented material that originated from weathering rocks and decomposing organic material that is transported by, suspended in, and eventually deposited in the streambed.
SEDIMENTATION
Occurs when sediment particles that have been suspended within flowing water are deposited on the stream bottom or floodplain.
SEMI-IMPERVIOUS SURFACE
A surface that allows a certain amount of rainfall or runoff to be abstracted or infiltrated into the substratum of the area.
SHEET FLOW
A flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.
SLAMM
Source Loading and Management Model. This model is based on small storm hydrology and pollutant runoff from urban land uses. Pollutant sources are identified, and both structural and nonstructural stormwater practices can be accounted for in the model.
SPECIAL FLOOD HAZARD AREA
Those areas identified by the Federal Emergency Management Agency (FEMA), Federal Insurance Administration (FIA) as floodway area (FW), flood fringe area (FF), and general floodplain area (FA); where determined by the Town, identified alluvial soils may be included as well.
STATE WATER QUALITY REQUIREMENTS
The regulatory requirements to protect, maintain, reclaim, and restore water quality under Pennsylvania Code Title 25 and the Clean Streams Law.[3]
STORM EVENT
The storm of a specific duration, intensity, and frequency.
STORMWATER MANAGEMENT BMPS
Is abbreviated as "SWM BMPs" or "BMPs" throughout this article.
STORMWATER MANAGEMENT ENGINEER
A professional engineer hired or appointed by the Town for the review of stormwater-management-related issues.
STORMWATER MANAGEMENT PRACTICES
The designed and/or constructed features which infiltrate, treat, collect, convey, channel, store, inhibit, or divert the movement of stormwater; such practices include structural and nonstructural practices.
STORMWATER MANAGEMENT SITE PLAN
The approved detailed analysis, design, and drawings of the stormwater management system are required for all construction. The plan prepared by the developer, or his representative indicates how stormwater runoff will be managed at the development site in accordance with this article. "Stormwater management site plan" will be designated as "SWM site plan" throughout this article.
STORMWATER or RUNOFF
Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
STRUCTURAL STORMWATER MANAGEMENT PRACTICES
Any measures that require the design and construction of a facility to help reduce or eliminate a non-point source of pollution and control stormwater.
STRUCTURE
Anything constructed or installed with a fixed location on the ground or attached to something having a fixed location on the ground.
SUBAREA (SUBBASIN)
A portion of the watershed (basin) that has similar hydrological characteristics and drains to a common point.
SUBDIVISION
As defined in the Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, No. 247.[4]
SUBGRADE
The top elevation of graded and compacted earth underlying roadway pavement.
SWALE
An artificial or natural waterway which may contain contiguous areas of standing or flowing water only following a rainfall event or is planted with or has stabilized vegetation suitable for soil stabilization, stormwater treatment, and nutrient uptake, or is designed to take into account the soil erodibility, soil percolation, slope, slope length, and contributing drainage area so as to prevent erosion and reduce the pollutant concentration of any discharge.
SWMM
Stormwater Management Model. EPA developed this model for analyzing stormwater quantity and quality associated with runoff from urban areas. Both single event and continuous simulation can be performed on catchments having storm sewers, or combined sewers and natural drainage, for prediction of flows, stages and pollutant concentrations. Information on SWMM is available at http://www.epa.gov/ceampubl/swater/swmm/index.htm.
TOTAL SITE AREA (SITE AREA)
Total area of the parcel(s) being developed.
USDA
United States Department of Agriculture.
USDOT FHWA
United States Department of Transportation, Federal Highway Administration.
WATER BODY
Any natural or artificial pond, lake, reservoir, or other area which ordinarily or intermittently contains water, and which has a discernible shoreline and receives surface water flow.
WATER TABLE
The uppermost level of saturation of pore space or fractures by subsurface water in an aquifer. "Seasonal high water table" refers to a water table that rises and falls with the seasons due either to natural or man-made causes.
WATERCOURSE
A permanent or intermittent stream or other body of water, whether natural or man-made, which gathers or carries surface water.
WATERS OF THE 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 underground water, or parts thereof, whether natural or artificial, within or on the boundaries of this commonwealth.
WATERSHED
A region or land area drained by a river, watercourse, or other surface water of this commonwealth to a downstream point.
WETLAND
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, including swamps, marshes, bogs, fens, and similar area.
WETLANDS
Land areas that are inundated or saturated by surface water or groundwater with 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, and similar areas); or areas that are defined and delineated in accordance with the Federal Manual for Identifying and Delineating Jurisdictional Wetlands, dated January 10, 1989, and as may be amended from time to time; or as further defined and delineated by the United States Army Corps of Engineers, the United States Environmental Protection Agency, or the Pennsylvania Department of Environmental Protection.
WOODLAND CONDITION
A natural ground cover with more than one viable tree of a DBH (diameter at breast height) of six inches or greater per 1,500 square feet which existed within 10 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.
[1]
Editor's Note: See 53 P.S. § 10503.
[2]
Editor's Note: See 35 P.S. § 691.1 et seq.
[3]
Editor's Note: See 35 P.S. § 691.1 et seq.
[4]
Editor's Note: See 53 P.S. § 10101 et seq.
[Ord. No. 1528, 9-26-2022]
(a) 
Standards and intent.
(1) 
The management of stormwater on-site, both during and upon completion of the disturbances associated with activities permitted under § 913.03, shall be accomplished in accordance with the standards and criteria of this article. The design of any temporary or permanent facilities and structures and the utilization of any natural drainage systems shall be in full compliance with this article.
(2) 
The intent of these design standards is to encourage environmentally sound stormwater management practices that provide necessary drainage facilities while protecting the hydrologic characteristics and water quality of the site and watershed. Developments shall be required to incorporate stormwater management controls. Stormwater management design shall blend into the natural environment and be aesthetically integrated into the site design.
(b) 
Applicants shall refer to the Pennsylvania Storm Water Best Management Practices Manual, as amended, Pennsylvania Handbook of Best Management Practices for Developing Areas (PACD, 1998), the 2000 Maryland Stormwater Design Manual (MDE, 2000) or other appropriate references for guidance in the design of stormwater management facilities most appropriate to individual site conditions. Objectives for design are to reduce the volume of stormwater generated, infiltrate runoff at its source to the maximum extent possible, achieve water quality improvement at the source or during conveyance, and provide for peak flow attenuation. Applicants shall examine design alternatives by viewing them in a series. In addition, applicants are strongly encouraged to use structural and nonstructural stormwater management practices that reduce or eliminate the need for detention basins.
(c) 
All SWM design work must be completed by a qualified design professional. All designs proposing the use of an SWM retention or detention facility with outlet structure(s) shall be completed by a professional engineer licensed in the Commonwealth of Pennsylvania.
(d) 
All development activity within a special flood hazard area designated by the Federal Emergency Management Agency (FEMA) shall comply with floodplain provisions of Article 1342 of the Town Code[1] and this paragraph subsection. All development shall be designed to maintain the flood-carrying capacity of the floodway such that the base flood elevations are not increased, either upstream or downstream, unless an approval is received from PADEP. The natural conveyance characteristics of the site and the receiving floodplain shall be incorporated into the stormwater management practices proposed for the site.
[1]
Editor's Note: See now Article 912, Floodplain Construction and Development Requirements.
(e) 
The stormwater management system shall not create an adverse impact on stormwater quantity or quality in either upstream or downstream areas. Off-site areas which discharge to or across a site proposed for development shall be addressed in the stormwater management plan prepared for the development. No stormwater management plan shall be approved until it is demonstrated that the runoff from the project shall not adversely impact downstream areas.
(f) 
Existing wetlands shall not be used to meet the minimum design requirements for stormwater management or stormwater runoff quality treatment, except when used as part of a treatment train that incorporates a portion of the outer zone (filter strip) of the wetland's riparian buffer as a stormwater outfall.
(g) 
All proposed stormwater management systems shall be designed to prevent the pollution of groundwater resources by stormwater, promote safety, minimize health hazards, preserve natural features and provide infiltration and groundwater recharge where appropriate. Neither submission of a plan under the provisions herein nor compliance with the provisions of these regulations shall relieve any person from responsibility for damage to any person or property otherwise imposed by law.
(h) 
Undue hardship. Waivers or modifications of the requirements of this article may be approved by the Town if enforcement will exact undue hardship because of unique physical circumstances or conditions peculiar to the land in question, provided that the modifications will not be contrary or detrimental to the public interest and will achieve the intended outcome, and that the purpose of this article is preserved. Hardship must be due to such unique physical circumstances or conditions and not to circumstances or conditions generally created by the provisions of this article. Cost or financial burden shall not be considered a hardship. Modifications shall not substantially or permanently impair the appropriate use or development of adjacent property. A request for modifications shall be in writing and accompany the stormwater management site plan submission.
(i) 
Where watercourses traverse a development site, drainage easements shall be provided conforming to the line of such watercourses. The terms of the easements shall prohibit excavation, the placing of fill or structures, except as needed for roadways, driveways and walkways, or any alterations that may adversely affect the flow of stormwater within any portions of the easement and require the establishment and protection of riparian buffers.
(j) 
For all regulated activities, stormwater management BMPs shall be designed, implemented, operated, and maintained to meet the purposes and requirements of this article and to meet all requirements under Pennsylvania Code Title 25, the Clean Streams Law, and the Storm Water Management Act.
(k) 
Any regulated activity that may affect the stormwater flows toward or onto a state or county highway right-of-way or facility shall be designed, implemented, operated, and maintained in accordance with the regulations of the Pennsylvania Department of Transportation (PennDOT) or Allegheny County, as the case may be.
(l) 
At the time of application for a building permit for any approved lot created by a subdivision and/or improved as a land development project, issuance of the permit shall be conditioned upon adherence to the terms of this article.
(m) 
Stormwater discharges to critical areas with sensitive resources (e.g., special-protection waters, cold water fisheries, recharge areas, water supply reservoirs, etc.) may be subject to additional performance criteria or may need to utilize or restrict certain stormwater management practices.
(n) 
For all regulated earth disturbance activities, erosion and sediment control BMPs shall be designed, implemented, operated, and maintained during the regulated earth disturbance activities (e.g., during construction) to meet the purposes and requirements of this article and to meet all requirements under Pennsylvania Code Title 25 and the Clean Streams Law. Various BMPs and their design standards are listed in the Erosion and Sediment Pollution Control Program Manual (E&S Manual), Commonwealth of Pennsylvania, Department of Environmental Protection, No. 363-2134-008, as amended and updated.
(o) 
No regulated earth disturbance activities within the Town shall commence until the requirements of this article are met.
(p) 
Post-construction water quality protection shall be addressed as required by the stormwater management requirements contained in this article.
(q) 
Operations and maintenance of permanent stormwater BMPs shall be addressed as required by § 913.19.
(r) 
All best management practices (BMPs) used to meet the requirements of this article shall conform to the state water quality requirements, and any more-stringent requirements as required by the Town.
(s) 
Techniques described in Appendix B (Nonstructural Stormwater Management Practices)[2] of this article are encouraged, because they reduce the costs of complying with the requirements of this article and the state water quality requirements.
[2]
Editor's Note: Appendix B is included as an attachment to this article.
(t) 
In selecting the appropriate BMPs or combinations thereof, the applicant shall consider the following:
(1) 
Total contributing area.
(2) 
Permeability and infiltration rate of the site soils.
(3) 
Slope and depth to bedrock.
(4) 
Seasonal high water table.
(5) 
Proximity to building foundations and wellheads.
(6) 
Erodibility of soils.
(7) 
Land availability and configuration of the topography.
(8) 
Peak discharge and required volume control.
(9) 
Stream bank erosion.
(10) 
Efficiency of the BMPs to mitigate potential water quality problems.
(11) 
The volume of runoff that will be effectively treated.
(12) 
The nature of the pollutant being removed.
(13) 
Maintenance requirements.
(14) 
Creation/protection of aquatic and wildlife habitat.
(u) 
Transference of runoff from one release rate district to another shall be prohibited unless approved by the Town.
(v) 
Completion of applicable PA DEP PCSM worksheets documenting volume, rate, and water quality requirements shall be completed for all projects unless they are considered a small project or do not require any stormwater management.
(w) 
At the discretion of the Town or the Town Engineer, the Town reserves the right to require the completion of additional studies for developments occurring in areas of concern.
[Ord. No. 1528, 9-26-2022]
(a) 
This section shall pertain to any and all persons making any change of land in the Town that will block, close, impede, or divert any existing drain or block, close, impede, or divert any watercourse or stormwater collection system.
(b) 
The provisions of this section are established with the following intentions:
(1) 
Preventing the creation of swamps, bogs, pools of drainage flow, stagnant water or other similar conditions that do, or threaten to, injuriously affect the health and welfare of the residents of the Town.
(2) 
Safeguarding the residents of the Town from consequences of flood and stormwaters diverted from their accustomed courses.
(c) 
Prohibited acts.
(1) 
No person shall block, close, impede or divert any watercourse or drain in the Town.
(2) 
No person shall cause discharge or drainage into a sewer line or into a drain or watercourse without first obtaining a written permit from the Town.
(3) 
No person shall make any construction on or adjacent to any street, alley or other public thoroughfare in the Town in such manner as to block, partially block or bridge any gutter, drain or watercourse in or adjacent to such street, alley or other public thoroughfare without first obtaining a written permit from the Town.
(4) 
No one shall be permitted to direct or divert water onto or into a public street or public street right-of-way so as to cause an accumulation of water or ice which, in the opinion of the Town Manager or Police Chief, constitutes a safety hazard.
(5) 
No person shall throw, drop, or deposit into any of the storm sewers within the Town any garbage, refuse, rubbish, petroleum, chemical products, liquid wastes, grass, tree or brush trimmings, or any litter, as defined by Town ordinance.
(6) 
No person(s) shall permit material from an unpaved road or unpaved driveway to enter a public road or public storm sewer.
(d) 
Permit; prerequisites. The Town shall issue a written permit authorizing any installation or construction otherwise a violation of § 913.09(c) only after:
(1) 
All applicable permits from the PA DEP, U.S. Army Corps of Engineers, and the Allegheny County Conservation District have been issued.
(2) 
The receipt of a dated request signed by the person desiring such installation or construction. If such request contemplates the installation of a sewer line, then such request shall set forth such information as will adequately locate the beginning and end of the sewer line, the type of sewer line to be used, the thickness of the wall of the sewer line to be used, the material from which the sewer line is constructed and the amount, contents and location of fill, if any, that will be placed over the sewer line to be installed. The request for any other installation or construction must set forth the proposed installation and/or construction in such detail as shall be requested by the Town.
(3) 
The Town ascertains that the construction and/or installation described above does not threaten to create any such condition as is sought to be avoided by the intent of this article.
(4) 
The applicant has furnished such engineering plans, specifications and information, or has agreed to reimburse the Town for the preparation of such engineering plans, specifications and information, as, in the opinion of the Town, may be required for a proper evaluation of the particular installation or construction.