For the purposes of this chapter, certain terms and words herein
shall be interpreted as follows:
A. Words used in the present tense include the future tense; the singular
number includes the plural, and the plural number includes the singular;
words of masculine gender include feminine gender; and words of feminine
gender include masculine gender.
B. The words "include" or "including" shall not limit the term to the
specific example but are intended to extend their meaning to all other
instances of like kind and character.
C. The word "person" includes an individual, firm, association, organization,
partnership, trust, company, corporation, or any other similar entity.
D. The words "shall" and "must" are mandatory; the words "may" and "should"
are permissive.
E. The words "used or occupied" include the words "intended, designed,
maintained, or arranged to be used, occupied or maintained."
The following words and phrases, when used in this chapter,
shall have the meanings given to them in this section unless the context
clearly indicates otherwise:
ACCELERATED EROSION
The removal of the surface of the land through the combined
action of human activity and the natural processes, at a rate greater
than would occur because of the natural process alone.
ACT
The Stormwater Management Act (Act of October 4, 1978, P.L.
864 No. 167; 32 P.S. §§ 680.1-680.17, as amended by
Act of May 24, 1984, No. 63).
AGRICULTURAL ACTIVITIES
The work of producing crops and raising livestock including
tillage, plowing, disking, harrowing, pasturing and installation of
conservation measures. Construction of new buildings or impervious
area is not considered an agricultural activity.
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; or, earth disturbance.
APPLICANT
A landowner, developer or other person who has filed an application
for approval to engage in any land development or for a development,
including his/her heirs, successors and assigns.
BMP (BEST MANAGEMENT PRACTICE)
Activities, facilities, designs, measures or procedures used
to manage stormwater impacts from land development, to meet state
water quality requirements, to promote groundwater recharge and to
otherwise meet the purposes of this chapter.
COUNTY
The County of Westmoreland, Pennsylvania.
CULVERT
A pipe, conduit or similar structure including appurtenant
works which carries a stream under or through an embankment or fill.
DAM
Any artificial barrier, together with its appurtenant works,
constructed for the purpose of impounding or storing water, or a structure
for highway, railroad or other purposes which may impound water.
DEP
The Pennsylvania Department of Environmental Protection.
DESIGN CRITERIA
A.
Engineering guidelines specifying construction details and materials.
B.
Objectives, results or limits which must be met by a facility,
structure or process in performance or its intended functions.
DESIGN STORM
The magnitude and temporal distribution of precipitation
from a storm event measured in probability of occurrence (e.g., two-year
storm) and duration (e.g., twenty-four-hour), and used in the design
and evaluation of stormwater BMPs.
DETENTION
The slowing, dampening, or attenuating of runoff flows entering
the natural drainage pattern or storm drainage system by temporarily
holding water on a surface area such as: detention basins, reservoirs,
on rooftops, in streets, parking lots, or underground structures,
or within the drainage system itself, and releasing the water at a
desired rate.
DETENTION BASIN
A basin designed to manage stormwater runoff by temporarily
storing the runoff and releasing it at a predetermined rate.
DEVELOPER
Any landowner, agent of such landowner, or tenant with the
permission of such landowner, who makes or causes to be made a subdivision
of land or a land development.
DEVELOPMENT
Any activity, construction, alteration, change in land use
or practice that affects stormwater runoff characteristics.
DEVELOPMENT SITE
A lot, parcel or tract of land where any land development
in the Township is proposed, conducted or maintained.
DISCHARGE
Volume rate of flow, specifically fluid flow. A volume of
fluid flowing from a conduit or channel, or being released from detention
storage, per unit of time. Commonly expressed as cubic feet per second
(cfs), gallons per minute (gpm), million gallons per day (mgd), or
cubic meters per second (cms).
DRAINAGE AREA
The contributing area to a single drainage basin, expressed
in acres, square miles or other units of area; also called a catchment
area, watershed, or river basin; the area served by a drainage system
or by a watercourse receiving storm and surface water.
DRAINAGE EASEMENT
A right granted by a landowner to a grantee allowing the
use of private land for stormwater management purposes.
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, embankment construction, land development, building
construction and the moving, depositing, stockpiling, or storing of
soil, rock or earth materials, road maintenance excluding periodic
resurfacing.
EROSION
The wearing away of the land surface by running water, wind,
ice, or other geological agents, including such process as gravitational
creep or by chemical agent.
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 this commonwealth.
FLOODPLAIN
A normally dry land area adjacent to stream channels that
is susceptible to being inundated by overbank stream flows. For regulatory
purposes, the Floodplain Management Act (Act of October 4, 1978, P.L.
851, No. 166) and regulations pursuant to the Act define the floodplain
as the area inundated by a one-hundred-year flood and delineated on
a map prepared by the Federal Emergency Management Agency (FEMA)
HIGH-QUALITY WATERS
Surface water having quality which exceeds levels necessary
to support propagation of fish, shellfish, and wildlife; and to support
recreation in and on the water by satisfying the regulations at 25
Pa. Code Chapter 93.
HYDRAULICS
The branch of engineering concerned with the mechanics of
fluids, especially liquids. As applied in stormwater management, the
study of the characteristics of flow of water in, and conveyance capacity
of, a watercourse, considering such factors as depth, velocity and
turbulence.
HYDROGRAPH
A graph showing, for a given point on a stream or for a given
point in any drainage system, the discharge, stage, or other property
of water, on the vertical axis, with respect to time, on the horizontal
axis.
HYDROLOGIC SOIL GROUP (HSG)
Soils are classified into four HSGs (A, B, C, and D) according
to their minimum infiltration rate. 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 a development
site may be identified from a soil survey report that can be obtained
from local NRCS offices or conservation district offices.
HYDROLOGY
The science dealing with the waters of the earth and their
distribution and circulation through the atmosphere. Engineering hydrology
deals with the application of hydrologic concepts to the design of
projects for the use and control of water.
IMPERVIOUS SURFACE
A surface which resists the entrance or passing through of
water or other liquids. Impervious surface includes, but is not limited
to, any roof, parking or driveway areas, and any new streets and sidewalks.
Any surface areas initially gravel or crushed stone that are designed
to ultimately be paved shall be assumed to be impervious surfaces.
INFILTRATION
Flow of water from the land surface into the subsurface.
LAND DEVELOPMENT
A.
Any earth disturbance, as defined herein;
B.
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; or
(2)
The division or allocation of land or space, whether proposed
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.
Land development as defined by the Municipalities Planning Code
[Section 107(a)].
NONPOINT SOURCE POLLUTION
Pollution that enters a water body from diffuse origins in
the watershed and does not result from discernible, confined, or discrete
conveyances.
NRCS
Natural Resource Conservation District (previously SCS, Soil
Conservation Service, U.S. Department of Agriculture).
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 (for computational purposes).
OUTFALL
Points or areas at which stormwater runoff leaves the site,
including but not limited to streams, storm sewers, swales or other
well-defined natural or artificial drainage features, as well as areas
of dispersed overland flows.
OUTLET STRUCTURE
A structure designed to control the volume of stormwater
runoff that passes through it during a specific length of time.
PADEP
Pennsylvania Department of Environmental Protection.
PEAK DISCHARGE
The maximum rate of flow of water at a given point resulting
from a specific storm event.
PERSON
An individual, partnership, association, corporation or a
governmental unit, public entity or any other legal entity whatsoever
which is recognized by law as the subject of rights and duties.
PERVIOUS SURFACE
A surface which permits the entrance or passing through of
water or other liquids.
POINT OF INTEREST
A point of hydrological and hydraulic importance used in
determining the peak discharge. These may include points of stream
confluences, an existing obstruction or problem area, or other similar
points.
POINT SOURCE
Any discernible, confined and discrete conveyance, including
but not limited to any pipe, ditch, channel, tunnel, well, discrete
fissure or container from which pollutants are or may be discharged,
as defined in state regulations at 25 Pa. Code Chapter 92a.
PROJECT PLAN
The required documentation of the stormwater management system to be used for a given development site, the contents of which are established in §§
280-14 and
280-15.
REDEVELOPMENT
Earth disturbance activities on land which has been previously
disturbed or developed.
REGULATED ACTIVITIES
Actions or proposed actions that have an impact on stormwater runoff and that are specified in §
280-4B of this chapter.
RUNOFF
Any part of precipitation that flows over the land surface.
SEDIMENT
Solid material, both mineral and organic, that is in suspension,
is being transported, or has been moved from its site of origin by
water; wind, gravity, or ice and has come to rest on the earth's
surface.
SEDIMENT BASIN
A barrier, dam, retention or detention basin located and
designed to retain rock, sand, gravel, silt, or other material transported
by water.
SEDIMENT POLLUTION
The placement, discharge or any other introduction of sediment
into the waters of this 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, wind, gravity or ice.
SHEET FLOW
Runoff that flows over the ground surface as a thin, even
layer, not concentrated in a channel.
SOIL-COVER COMPLEX METHOD
A method of runoff computation developed by the NRCS and
found in its publication "Urban Hydrology for Small Watersheds," Technical
Release No. 55, June 1986 (or most current edition).
STORM FREQUENCY
The number of times that a given storm event occurs or is
exceeded on the average in a stated period of years. For example,
the twenty-five-year storm would be expected to recur on the average
once every 25 years.
STORM SEWER
A system of pipes and/or open channels that convey intercepted
surface runoff, street water, and other washwaters, or drainage, but
excludes domestic sewage and industrial wastes.
STORMWATER
The total amount of precipitation reaching the ground surface.
STORMWATER COLLECTION SYSTEM
Any structures, natural or man-made, which collect and transport
stormwater through or from a drainage area to the point of final outfall,
including but not limited to any of the following: conduits and appurtenant
features, canals, channels, ditches, streams, culverts, streets and
appurtenant drainage facilities.
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.
SUBAREA
A portion of a watershed that has similar hydrological characteristics
and drains to a common point.
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, transfer of ownership,
or building or lot development.
SURFACE 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 water, or parts thereof, whether natural or artificial, within
or on the boundaries of the Commonwealth of Pennsylvania.
SWALE
A low-lying stretch of land which gathers or conveys surface
water runoff.
TIME OF CONCENTRATION (Tc)
The time for surface runoff to travel from the hydraulically
most distant point of the watershed to the outflow location.
TOWNSHIP
Upper Burrell Township, Westmoreland County, Pennsylvania.
VOLUME OF STORMWATER RUNOFF
Quantity of water normally measured in inches, cubic feet,
or acre-feet, measured or determined analytically from runoff coefficients;
rainfall/runoff ratios; and areas underneath hydrographs.
WATERCOURSE
Any channel of conveyance of surface water having a defined
bed and banks, whether natural or man-made, with perennial or intermittent
flow.
WATERSHED
The entire region or area bounded peripherally by water parting
and draining to a particular watercourse or body of water.
WETLANDS
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, and similar areas.