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.
AASHTO
American Association of State Highway and Transportation
Officials.
ACCELERATED EROSION
The 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.
ALLUVIAL SOILS
Those areas delineated pursuant to the Columbia County, Pennsylvania,
Soil Survey, November 1986, and as may be amended from time to time.
ALTERATION
As applied to land, a change in topography as a result of
the moving of soil and rock from one location or position to another;
also the changing of surface conditions by causing the surface to
be more or less impervious; land disturbance.
APPLICANT
A 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, detention basins, and manufactured devices. Structural stormwater
BMPs are permanent appurtenances to the project site.
CARBONATE
A sediment formed by the organic or inorganic precipitation
of mineral compounds characterized by the fundamental chemical ion
CO3. The principal element in limestone and
dolomite strata.
CHANNEL
A perceptible natural or artificial waterway which periodically
or continuously contains moving water, having a definite bed and banks
which confine the water.
CHANNEL EROSION
The widening, deepening and headward cutting of small channels
and waterways.
CISTERN
An underground reservoir or tank for storing rainwater.
CLOSED OR UNDRAINED DEPRESSION
In a karst geologic area, a distinct bowl-shaped depression
in the land surface; size and amplitude are variable; drainage is
internal. It differs from a sinkhole in that the ground surface is
unbroken and usually occurs in greater density per unit area.
CULVERT
A structure with appurtenant works which carries a stream
under or through an embankment or fill.
DAM
An 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 which does or may impound water or another
fluid or semifluid.
DESIGN STORM
The magnitude of precipitation from a storm event of a specified
recurrence interval (e.g., one-hundred-year recurrence interval) and
duration (e.g., 24 hours), and used in designing stormwater management
systems.
DETENTION BASIN
A basin designed to retard stormwater runoff by temporarily
storing the stormwater runoff and releasing it at a predetermined
rate. A detention basin 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).
DEVELOPER
An 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 SITE
The specific tract of land for which a regulated activity
is proposed.
DRAINAGE EASEMENT
A right granted by a landowner to a grantee, allowing the
use of private land for stormwater management purposes.
DRAINAGE PLAN
The documentation of the stormwater management system, if any, to be used for a given development site, the contents of which are established in Article
II of this chapter.
EASEMENT
A 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 which is not inconsistent with the rights
of the grantee.
EROSION
The removal of soil, stone and other surface materials by
the action of natural elements.
FLOOD
A 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.
FLOODPLAIN
Any land area susceptible to inundation by water from any
natural source, or delineated by applicable Department of Housing
and Urban Development, Federal Insurance Administration Flood Hazard
Boundary-Mapped as being a special flood hazard area. Also included
are areas that comprise Group 13 Soils, as listed in Appendix A of
the PA DEP Technical Manual for Sewage Enforcement Officers (as amended
or replaced from time to time by PA DEP).
FOREST MANAGEMENT
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.
Timber harvesting that is in preparation for future land development
is not considered forest management under this chapter.
GABION
A large rectangular box of heavy gage wire mesh which holds
large cobbles and boulders. Used in streams and ponds to change flow
patterns, stabilize banks, or prevent erosion.
GEOLOGIC FORMATION
The basic or fundamental rock stratigraphic unit in the local
classification of rocks, consisting of a body of rock (usually a sedimentary
stratum or strata but also igneous or metamorphic) generally characterized
by some degree of internal lithologic homogeneity or distinctive lithologic
features (such as chemical composition, structures, textures, gross
aspect of fossils, or time of deposition). Typically used for mapping
the geology of an area.
GEOLOGIC MEMBER
A rock stratigraphic unit which is subordinate (a subject)
of a formation. This unit is not necessarily mappable and is usually
a unified subdivision of local extent that may or may not be contained
in more than one formation.
GHOST LAKE
A body of standing water occurring in a sinkhole or closed
depression of a karst region that is usually visible after sufficient
precipitation has occurred. They may form from slow permeability of
soils, rises in the water table or the development of a natural liner
of slow permeable clays or soils.
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.
GRADING
The act of excavating and/or filling land for the purpose
of changing natural slope.
IMPERVIOUS AREA
Impermeable surface, such as pavement or rooftops, which
limits the infiltration of water into the soil.
IMPOUNDMENT
A retention or detention basin designed to retain stormwater
runoff and release it at a specified rate.
INFILTRATION STRUCTURE
A structure designed to direct stormwater runoff into the
ground, such as french drains, seepage pits or seepage trenches.
INLET
A 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.
KARST
A 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 DEVELOPMENT
Any 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;
(2)
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.
C.
Development in accordance with Section 503(1.1) of the Pennsylvania
Municipalities Planning Code [53 P.S. § 10503(1.1)].
LAND DISTURBANCE
Any activity involving grading, tilling, digging or filling
of ground, stripping of vegetation, or any other activity that causes
land to be exposed to erosion and/or impacts stormwater runoff characteristics.
LEVEL SPREADER
A 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.
LINEAMENTS
Straight or gently curved, lengthy features frequently expressed
topographically as depressions or lines on the earth's surface.
They can be more easily observed at a height of 100 meters or more
and are usually found by researching aerial photographs or satellite
photography. They are usually located in areas of faulting or in dense
jointing along some rock stratigraphy.
LOW FLOW CHANNEL
An incised or paved channel from inlet to outlet in a dry
basin which is designed to carry low stormwater runoff flows and/or
base flow directly to the outlet without detention.
MS4
Municipal separate storm sewer system.
MUNICIPAL ENGINEER
A registered professional engineer engaged by Scott Township
to provide municipal engineering services.
NPDES
National Pollutant Discharge Elimination System.
NRCS
USDA, Natural Resources Conservation Service (previously
SCS).
OPEN CHANNEL
A 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.
OUTLET
Points of water disposal from a stream, river, lake, tidewater
or artificial drain.
PA DEP
The Pennsylvania Department of Environmental Protection.
PEAK DISCHARGE
The maximum rate of flow of water at a given point and time
resulting from a storm event.
PENNDOT
The Pennsylvania Department of Transportation.
PIPE
A culvert, closed conduit or similar structure (including
appurtenances) that conveys stormwater.
PLANNED RESIDENTIAL DEVELOPMENT
An 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 ENGINEER
An 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 and conveyance systems.
PROFESSIONAL GEOLOGIST
An 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 SURVEYOR
An 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 and conveyance systems.
RECORD DRAWING
A 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.
RECURRENCE INTERVAL
The 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 ARCHITECT
A 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 and conveyance
systems.
REGISTERED PROFESSIONAL
See "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 earthmoving, forest management,
land development, land disturbance and subdivision, and any activities
that may contribute nonstormwater discharges to a regulated small
MS4.
RESPONSIBLE PARTY
A "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 BASIN
A basin in which stormwater runoff from a given flood event
is stored and is not discharged into the downstream drainage system
during the flood event.
RIPRAP
A combination of large stone, cobbles and boulders used to
line channels, stabilize banks, and reduce stormwater runoff velocities.
RISER
A vertical pipe, extending from the bottom of a detention
basin, that is used to limit the discharge rate from the detention
basin for a specified design storm.
RUNOFF
Any part of precipitation that flows over the land surface.
SCS
USDA, Soil Conservation Service (now NRCS).
SEDIMENT BASIN
A barrier, dam, retention or detention basin located and
designed to retain rock, sand, gravel, silt or other water-transported
material.
SEDIMENT POLLUTION
The 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.
SEDIMENTATION
The process by which mineral or organic matter is accumulated
or deposited by the movement of water.
SEEPAGE PIT/SEEPAGE TRENCH
An area of excavated earth filled with loose stone or similar
coarse material, into which surface water is directed for infiltration
into the ground.
SHEET FLOW
Stormwater runoff which flows over the ground surface as
a thin even layer, not concentrated in a channel. Flow depth is generally
0.1 feet or less.
SINKHOLE
A 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.
SINKHOLE FLOODPLAIN
The area inundated by the twenty-four-hour one-hundred-year
recurrence interval design storm, assuming no drainage from the sinkhole
or closed depression, based upon anticipated stormwater runoff volumes
with maximum development permitted by zoning within the catchment
area or area draining to the sinkhole.
SOIL-COVER-COMPLEX METHOD
A method of computing stormwater runoff developed by NRCS
and found in its publication National Engineering Handbook, Part 630
– Hydrology (USDA, NRCS).
SPILLWAY
A depression in the embankment of a detention basin which
is used to pass peak discharge greater than the maximum design storm
that said detention basin was designed for.
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 Stream Law.
STORM SEWER
A system of pipes or other conduits which carry intercepted
surface stormwater runoff, street water and other water or drainage,
excluding domestic sewage and industrial wastes.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
STORMWATER MANAGEMENT FACILITY
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 basins, open channels, storm
sewers, pipes and infiltration structures.
STRATA
Tabular 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.
STRATIGRAPHIC UNIT
A stratum or body of strata recognized as a unit in the classification
of the rocks of the earth's crust with respect to any specific
rock character, property, attribute or for any purpose such as description,
mapping and correlation.
SUBAREA
The smallest drainage unit of a watershed for which stormwater
management criteria have been established in the stormwater management
plan.
SUBDIVISION
The division or redivision of a lot, tract or parcel of land
by any means into two or more lots, tracts, parcels or other divisions
of land, including changes in existing lot lines for the purpose,
whether immediate or future, of lease, partition by the court for
distribution to heirs or devisees, transfer of ownership or building
or lot development; provided, however, that the subdivision by lease
of land for agricultural purposes into parcels of more than 10 acres,
not involving any new street or easement of access or any residential
dwelling, shall be exempted.
SWALE
A low-lying stretch of land or wide shallow ditch, usually
grassed or paved, which gathers or carries stormwater runoff.
TIME OF CONCENTRATION
The 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.
TOPOGRAPHY
The 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.
USACE
United States Army Corps of Engineers.
USDA
United States Department of Agriculture.
WATERCOURSE
A stream of water, river, brook, creek or a channel or ditch
for water, whether natural or man-made.
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 the commonwealth.
WATERSHED
The entire region or area drained by a river or other body
of water, whether natural or artificial; a drainage basin or subbasin.
WETLAND
Those 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.