The following words and phrases, when used in this chapter, shall have, unless the context clearly indicates otherwise, the meanings given to them in this section. All words and terms not defined herein shall be used with a meaning of standard usage.
AASHTOAmerican Association of State Highway and Transportation Officials.
ACCELERATED EROSIONThe removal of the surface of the land through the combined action of man's activity and natural processes at a rate greater than would occur because of the natural process alone.
AGRICULTURAL ACTIVITY (ACTIVITIES)The work of producing crops including tillage, land clearing, plowing, disking, harrowing, planting, harvesting crops, or pasturing and raising of livestock; and installation of nonstructural conservation measures. Construction of any new building(s) and/or the creation of any new impervious area(s) are regulated activities and are not agricultural activities.
ALTERATIONAs applied to land, a change in topography as a result of the moving of soil and rock from one location or position to another; also the changing of surface conditions by causing the surface to be more or less impervious; any earth-disturbance activity.
APPLICANTA landowner or developer who undertakes any regulated activity.
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 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, stormwater detention facilities, and manufactured devices. Structural stormwater BMPs are permanent appurtenances to the project site.
CARBONATEA sediment formed by the organic or inorganic precipitation of mineral compounds characterized by the fundamental chemical ion CO.3 The principle element in limestone and dolomite strata.
CHANNELA perceptible natural or artificial waterway that periodically or continuously contains moving water having a defined bed and banks that confine the water.
CHANNEL EROSIONThe widening, deepening, and headward cutting of small channels and waterways.
CISTERNAn underground reservoir or tank for storing rainwater.
CULVERTA structure with appurtenant works that carries a stream under or through an embankment or fill.
DAMAn artificial barrier, together with its appurtenant works, constructed for the purpose of impounding or storing water or another fluid or semifluid; or a refuse bank, fill or structure for highway, railroad, or other purposes that does or may impound water or another fluid or semifluid.
DESIGN STORMThe magnitude of precipitation from a storm event of a specified recurrence interval (e.g., 100-year recurrence interval) and duration (e.g., 24 hours), and used in designing stormwater management facilities.
DETENTION FACILITY (FACILITIES)A stormwater management facility designed to retard stormwater runoff by temporarily storing the stormwater runoff and releasing it at a predetermined rate. A detention facility may be designed to drain completely after a storm event (dry pond), or it may be designed to contain a permanent pool of water (wet pond).
DEVELOPERAn individual, public or private association or corporation, partnership, association, municipality or political subdivision of the Commonwealth of Pennsylvania, public utility, institution, authority, firm, trust, estate, receiver, guardian, personal representative, successor, joint venture, joint stock company, fiduciary; Department, agency or instrumentality of state, federal or local government, or an agent or employee thereof; or any other legal entity who undertakes a regulated activity.
DEVELOPMENT SITEThe specific tract of land for which a regulated activity is proposed.
DRAINAGE EASEMENTA right granted by a landowner to a grantee, allowing the use of private land for stormwater management purposes.
DRAINAGE PLANThe documentation of the stormwater management facilities, if any, to be used for a given development site, the contents of which are established in Article
II of this chapter.
A construction or other human activity that disturbs the surface of the land, including, but not limited to: clearing and grubbing; grading; tilling; digging; filling; excavations; embankments; road maintenance; building construction; stripping of vegetation; the moving, depositing, stockpiling, or storing of soil, rock, or earth materials; or any activity that causes land to be exposed to erosion and/or impacts stormwater runoff characteristics.
EASEMENTA recorded agreement of right-of-way granted, but not dedicated, for limited use of private land for a public or quasi-public purpose, identified on plan drawings, and within which the owner of the property shall not erect any permanent structures, but shall have the right to any other use of the land that is not inconsistent with the rights of the grantee.
EROSIONThe removal of soil, stone, and other surface materials by the action of natural elements.
FEMAFederal Emergency Management Agency.
FLOODA general but temporary condition of partial or complete inundation of normally dry land areas from the overflow of streams, rivers, and other waters of the Commonwealth.
FLOOD INSURANCE RATE MAP (FIRM)The official map on which FEMA has delineated both the special flood hazard areas (SFHAs) and the risk premium zones applicable to the Municipality.
FLOODPLAINAny land area susceptible to inundation by water from any natural source or delineated by applicable FEMA maps and studies as being a special flood hazard area (SFHA). Also includes areas that comprise Group 13 Soils, as listed in Appendix A of the Pennsylvania DEP Technical Manual for Sewage Enforcement Officers (as amended or replaced from time to time by DEP).
FOREST MANAGEMENTPlanning and activities necessary for the management of forest land. 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. Timber harvesting that is in preparation for future land development is not considered forest management under this chapter.
GRADE A slope, usually of a road, channel, or natural ground specified in percent, and shown on plans as specified herein. (To) GRADE — To finish the surface of a roadbed, top of embankment, or bottom of excavation.
GRADINGThe act the excavating and/or filling land for the purpose of changing natural slope.
IMPERVIOUS AREAImpermeable surfaces, such as pavement or rooftops, that limit the infiltration of water into the soil.
IMPOUNDMENTA stormwater retention or stormwater detention facility designed to retain stormwater runoff and release it at a specified rate.
INLETA surface connection to a closed drain. A structure at the diversion end of a conduit. The upstream end of any structure through which water may flow.
KARSTA type of topography that is formed over limestone, dolomite, or gypsum by bedrock solution, and that is characterized by closed depressions or sinkholes, caves, and underground drainage (from AGI, Glossary of Geology, 1972).
LAND DEVELOPMENTAny of the following activities:
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 residential or nonresidential buildings, whether proposed initially or cumulatively, or a single nonresidential building on a lot or lots regardless of the number of occupants or tenure; or
The division or allocation of land or space, whether initially or cumulatively, between or among two or more existing or prospective occupants by means of, or for the purpose of streets, common areas, leaseholds, condominiums, building groups or other features;
Development in accordance with Section 503(1.1) of the Pennsylvania Municipalities Planning Code (current edition).
LEVEL SPREADERA device used to spread out stormwater runoff uniformly over the ground surface as sheet flow (i.e., not through channels). The purpose of level spreaders is to prevent concentrated, erosive flows from occurring, and to enhance infiltration.
LOW-IMPACT DEVELOPMENTSite design approaches and small-scale stormwater management practices that promote the use of natural systems for infiltration, evapotranspiration, and reuse of rainwater. Low-impact development can be applied to new development, urban retrofits, and revitalization projects. Low-impact development 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, low-impact development addresses stormwater through a variety of small, cost-effective landscape features located on-site.
MS4 (MUNICIPAL SEPARATE STORM SEWER SYSTEM)A conveyance or system of conveyances that is:
A. Owned by a state, city, town, village, or other public entity that discharges to waters of the U.S.;
Designed or used to collect or convey stormwater (e.g., storm drains, pipes, ditches);
Not a combined sewer; and
Not part of a sewage treatment plant, or publicly owned treatment works.
MUNICIPAL ENGINEERA registered professional engineer engaged by Scott Township to provide municipal engineering services.
NPDESNational Pollutant Discharge Elimination System.
NRCSUSDA, Natural Resources Conservation Service (previously SCS).
OPEN CHANNELA drainage element in which stormwater flows with an open surface. Open channels include, but shall not be limited to, natural and man-made drainageways, swales, streams, ditches, canals, and pipes flowing partly full.
OUTLETPoints of water disposal from a stream, river, lake, tidewater, or artificial drain.
PA DEPThe Pennsylvania Department of Environmental Protection.
PEAK DISCHARGEThe maximum rate of flow of water at a given point and time resulting from a storm event.
PENNDOTThe Pennsylvania Department of Transportation.
PIPEA culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.
PLANNED RESIDENTIAL DEVELOPMENTAn area of land, controlled by a landowner, to be developed as a single entity for a number of dwelling units, or combination of residential and nonresidential uses, the development plan for which does not correspond in lot size, bulk, type of dwelling, or use, density, or intensity, lot coverage and required open space to the regulations established in any one district created, from time to time, under the provisions of a municipal zoning ordinance.
PROFESSIONAL ENGINEERAn individual actively licensed and registered under the laws of Pennsylvania to engage in the "Practice of Engineering" (as defined by Commonwealth of Pennsylvania Act of May 23, 1945, P.L. 913, No. 367 CI. 63, and as amended). For the purposes of this chapter, said individual must be trained and experienced in the design of stormwater management facilities.
PROFESSIONAL GEOLOGISTAn individual actively licensed and registered under the laws of Pennsylvania to engage in the "Practice of Geology" (as defined by Commonwealth of Pennsylvania Act of May 23, 1945, P.L. 913, No. 367 CI. 63, and as amended).
PROFESSIONAL LAND SURVEYORAn individual actively licensed and registered under the laws of Pennsylvania to engage in the "Practice of Land Surveying" (as defined by Commonwealth of Pennsylvania Act of May 23, 1945, P.L. 913, No. 367 CI. 63, and as amended). For the purposes of this chapter, said individual must be trained and experienced in the design of stormwater management facilities.
RECORD DRAWINGA drawing prepared by a registered professional that depicts the constructed (as-built) improvements associated with a regulated activity. Such improvements include (but are not limited to) buildings, driveways, grading, parking areas, stormwater management facilities, streets, etc. The record drawing shall show both design and as-built data for improvements associated with a regulated activity.
RECURRENCE INTERVALThe average interval, in years, within which a rainfall event of a given magnitude and duration can be expected to recur. For example, a twenty-five-year recurrence interval event would be expected to recur on the average once every 25 years.
REGISTERED LANDSCAPE ARCHITECTA person actively licensed and registered under the laws of Pennsylvania who engages or offers to engage in the "Practice of Landscape Architecture" [as defined by Commonwealth of Pennsylvania Act of January 24, (1966) 1965, P.L. 1527, No. 535 CI 63, and as amended]. For the purposes of this chapter, said person must be trained and experienced in the design of stormwater management facilities.
REGISTERED PROFESSIONALSee "professional engineer," "professional geologist," "professional land surveyor," and "Registered Landscape Architect."
REGULATED ACTIVITY (ACTIVITIES)Action(s) or proposed action(s) that impact stormwater runoff in any manner, including, but not limited to, any earth-disturbance activity, forest management, land development, subdivision, and any activities that may contribute nonstormwater discharges to any receiving stream(s).
RESPONSIBLE PARTYA "person" as defined in the Storm Water Management Act, Act of October 4, 1978, P.L. 864 Number 167, 32 P.S. § 680.1 et seq. (as amended).
RETENTION FACILITY (FACILITIES)A stormwater management facility in which stormwater runoff from a given flood event is stored and is not discharged into the downstream drainage system during a storm event.
RIPRAPA combination of large stone, cobbles, and boulders used to line channels, stabilize banks, and reduce stormwater runoff velocities.
RISERA vertical structure, extending from the bottom of a detention facility, that is used to limit the discharge rate from the detention facility for a specified design storm.
RUNOFFAny part of precipitation that flows over the land surface.
SCSUSDA, Soil Conservation Service (now NRCS).
SEDIMENT POLLUTIONThe placement, discharge, or any other introduction of sediment into the waters of the Commonwealth occurring from the failure to design, construct, implement, or maintain control measures and control facilities in accordance with the requirements of this chapter.
SEDIMENTATIONThe process by which mineral or organic matter is accumulated or deposited by the movement of water.
SEEPAGE PIT/SEEPAGE TRENCHAn area of excavated earth filled with loose stone or similar coarse material, into which surface water is directed for infiltration into the ground.
SHEET FLOWStormwater runoff that flows over the ground surface as a thin, even layer, not concentrated in a channel. Flow depth is generally 0.1 feet or less.
SINKHOLEA localized, gradual or rapid sinking of the land surface to a variable depth, occurring in areas of carbonate bedrock; generally characterized by a roughly circular outline, a distant breaking of the ground surface and downward movement of soil into bedrock voids.
SPILLWAYA depression in the embankment of a detention facility that is used to pass peak discharge greater than the maximum design storm that said detention facility was designed for.
STATE WATER QUALITY REQUIREMENTSThe regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code and the Clean Stream Law.
STORM SEWERA system of pipes or other conduits that carry intercepted surface stormwater runoff, street water, and other water or drainage, excluding domestic sewage and industrial wastes.
STORMWATERDrainage runoff from the surface of the land resulting from precipitation, or snow or ice melt.
STORMWATER MANAGEMENT FACILITY (FACILITIES)Any structure, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff. Typical stormwater management facilities include, but are not limited to, detention and retention facilities, open channels, storm sewers, pipes, and infiltration structures.
STRATATabular or sheet-like mass, distinct layers of homogenous or gradational sedimentary material (consolidated rock or unconsolidated earth) of any thickness, visually separable from other layers above and below by a discrete change in the character of the material deposited, or by a sharp physical break, deposition, or both.
SUBAREAThe smallest drainage unit of a watershed for which stormwater management criteria have been established in the stormwater management plan.
SUBDIVISIONThe division or redivision of a lot, tract or parcel of land by any means into two or more lots, tracts, parcels or other divisions of land including changes in existing lot lines for the purpose, whether immediate or future, of lease, partition by the court for distribution to heirs or devisees, transfer of ownership or building or lot development; provided, however, that the subdivision by lease of land for agricultural purposes into parcels of more than 10 acres, not involving any new street or easement of access or any residential dwelling, shall be exempted.
SWALEA low-lying stretch of land or wide shallow ditch, usually grassed or paved, that gathers or carries stormwater runoff.
TIME OF CONCENTRATIONThe time for surface runoff to travel from the hydraulically most distant point of the watershed to a point of interest within the watershed. This time is the combined total of overland flow time and flow time in any pipes or channels.
TOPOGRAPHYThe general configuration of a land surface or any part of the earth's surface, including its relief and position of its natural and man-made features. The natural or physical surface features of a region, considered collectively as to its form.
USACEUnited States Army Corps of Engineers.
USDAUnited States Department of Agriculture.
WATERCOURSEA stream of water, river, brook, creek, or a channel or ditch for water, whether natural or man-made.
WATERS OF THE COMMONWEALTHAny 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 the Commonwealth.
WATERSHEDThe entire region or area drained by a river or other body of water, whether natural or artificial; a drainage basin or subbasin.
WETLANDThose areas that are inundated or saturated by surface or ground water 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, ferns, and similar areas.