[Ord. 2014-04, 4/28/2014, § 23-202]
Unless otherwise stated, the following words shall, for the
purpose of this chapter, have the meaning herein indicated:
ACCELERATED EROSION
The removal of the surface of the land through the combined
action of man's activities and natural processes at a rate greater
than would occur because of the natural processes alone.
ACT 167 PLAN
The watershed stormwater management plan prepared under the
authority of the Storm Water Management Act and approved by DEP for
the watershed in which the subject property is located.
AGRICULTURAL ACTIVITIES
Activities associated with agriculture such as agricultural
cultivation, agricultural operation, and animal heavy use areas. This
includes the work of producing crops and raising livestock including
tillage, land clearing, plowing, disking, harrowing, planting, harvesting
crops, or pasturing and raising of livestock and installation of conservation
practices. Construction of new buildings or impervious areas 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; earth disturbance.
ANIMAL HEAVY USE AREAS
A barnyard, feedlot, loafing area, exercise lot, or other
similar area on an agricultural operation where due to the concentration
of animals, it is not possible to establish and maintain vegetative
cover of a density capable of minimizing accelerated erosion and sedimentation
by usual planting methods. The term does not include entrances, pathways
and walkways between areas where animals are housed or kept in concentration.
APPLICANT
A landowner and/or developer, as hereinafter defined, including
his heirs, successors and assigns, who has filed an application to
the municipality for approval to engage in any regulated activity
at a development site located within the municipality.
BMP (BEST MANAGEMENT PRACTICE)
Activities, facilities, control measures, planning or procedures
used to minimize accelerated erosion and sedimentation and manage
stormwater to protect, maintain, reclaim, and restore the quality
of waters and the existing and designated uses of waters within this
Commonwealth before, during and after earth disturbance activities.
See also BMP, non-structural and BMP, structural.
BMP, NON-STRUCTURAL
Planning and design approaches, operational and/or behavior-related
practices which minimize stormwater runoff generation resulting from
an alteration of the land surface or limit contact of pollutants with
stormwater runoff.
BMP, STRUCTURAL
Physical devices and practices that capture and treat stormwater
runoff which are permanent appurtenances to the development site.
BMP MANUAL
The Pennsylvania Stormwater Best Management Practices Manual
of December 2006, or most recent version thereof.
CHANNEL
A natural or artificial watercourse with a definite bed and
banks which confine and conduct continuously or periodically flowing
water.
CHAPTER 102
25 Pa.Code, Chapter 102, "Erosion and Sediment Control."
CHAPTER 105
25 Pa.Code, Chapter 105, "Dam Safety and Waterway Management."
CHAPTER 106
25 Pa.Code, Chapter 106, "Floodplain Management."
CISTERN
A reservoir or tank for storing rainwater.
CLEAN WATER ACT
The 1972 amendments to the Federal Water Pollution Control
Act, P.L. 92-500 of 1972, 33 U.S.C. § 1251 et seq.
CONSERVATION PLAN
A plan written by an NRCS certified planner that identifies
conservation practices and includes site specific BMPs for agricultural
plowing or tilling activities and animal heavy use areas.
CONSERVATION PRACTICES
Practices installed on agricultural lands to improve farmland,
soil and/or water quality which have been identified in a current
conservation plan.
CONVEYANCE
The ability of a pipe, culvert, swale or similar facility
to carry the peak flow from the design storm.
CULVERT
A structure with appurtenant works which carries a watercourse
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. The dam falls under the requirements of 25 Pa.Code,
Chapter 105, "Dam Safety and Waterway Management," if the following
is true:
(1)
The contributory drainage area exceeds 100 acres.
(2)
The greatest depth of water measured by upstream toe of the
dam at maximum storage elevation exceeds 15 feet.
(3)
The impounding capacity at maximum storage elevation exceeds
50 acre-feet.
DCNR
The Pennsylvania Department of Conservation and Natural Resources
or any agency successor thereto.
DEP
The Pennsylvania Department of Environmental Protection or
any agency successor thereto.
DESIGN STORM
The magnitude of precipitation from a storm event measured
in probability of occurrence (e.g., fifty-year storm) and duration
(e.g., twenty-four-hour), and used in the design and evaluation of
stormwater management facilities.
DETENTION BASIN
An impoundment structure 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, or other regulated activity covered
by this chapter.
DEVELOPMENT
Any man-made change to improved or unimproved real estate,
including, but not limited to, buildings or other structures, mining,
dredging, filling, grading, paving, excavation or drilling operations.
DEVELOPMENT SITE
The specific area of land where regulated activities in the
Township are planned, conducted or maintained.
DRAINAGE CONVEYANCE FACILITY
A stormwater management facility designed to transmit stormwater
runoff and shall include streams, channels, swales, pipes, conduits,
storm sewers, etc.
DRAINAGE EASEMENT
A right granted by a landowner to a grantee, allowing the
use of private land for stormwater management purposes or for the
maintenance of natural drainageways to preserve and maintain a channel
for the flow of stormwater therein, or to safeguard health, safety,
property, and facilities.
E&S MANUAL
The Erosion and Sediment Pollution Control Program Manual,
Number 363-2134-008, prepared by DEP.
EARTH DISTURBANCE
Any activity involving grading, tilling, digging or filling
of ground, or stripping of vegetation, or any other activity which
causes land to be exposed to the danger of erosion.
EARTH DISTURBANCE ACTIVITY
A construction or other human activity which disturbs the
surface of the land, including, but not limited to: clearing and grubbing;
grading; excavations; embankments; land development; agricultural
plowing or tilling; operation of animal heavy use areas; timber harvesting
activities; road maintenance activities; oil and gas activities; well
drilling; mineral extraction; building construction; and the moving,
depositing, stockpiling, or storing of soil, rock, or earth materials.
EPHEMERAL STREAM
A water conveyance which lacks substrates associated with
flowing waters and flows only in direct response to precipitation
in the immediate watershed or in response to melting snowpack and
which is always above the local water table.
EROSION
The removal of soil particles by the action of water, wind,
ice, or other geological agents.
EXISTING CONDITIONS
The initial condition of a development site prior to the
proposed construction and the dominant land cover during the five-year
period immediately preceding a proposed regulated activity.
FEMA
The Federal Emergency Management Agency, or any agency successor
thereto.
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
An area meeting the definition of floodplain in Chapter
27, "Zoning."
FLOODWAY
An area meeting the definition of Floodway in Chapter
27, "Zoning." In an area where no FEMA maps or studies have defined the boundary of the one-hundred-year frequency floodway, it is assumed, absent evidence to the contrary, that the floodway extends 50 feet outward from the top of each stream bank.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forest
land. These include conducting a timber inventory and preparation
of forest management plans, silvicultural treatment, cutting budgets,
logging road design and construction, timber harvesting, site preparation
and reforestation.
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.
GRASSED WATERWAY
A natural or constructed waterway, usually broad and shallow,
covered with erosion-resistant grasses, used to conduct surface water
from cropland.
GROUNDWATER RECHARGE
Replenishment of existing natural underground water supplies
and aquifer by adding water from above the ground surface.
HIGH TUNNEL
A structure which meets the following:
[Added by Ord. No. 2019-06, 10/14/2019]
(1)
Is used for the production, processing, keeping, storing, sale
or shelter of an agricultural commodity as defined in Section 2 of
the Act of December 19, 1974 (P.L. 973, No. 319), known as the "Pennsylvania
Farmland and Forest Land Assessment Act of 1974," or for the storage of agricultural equipment or supplies.
(2)
Is constructed consistent with all of the following:
(a)
Has a metal, wood or plastic frame.
(b)
When covered, has a plastic, woven textile or other flexible
covering.
(c)
Has a floor made of soil, crushed stone, matting, pavers or
a floating concrete slab.
ILLICIT CONNECTION
Any man-made physical connection or prohibited connection
to the MS4 that conveys an illicit discharge.
[Added by Ord. No. 2022-06, 9/12/2022]
ILLICIT DISCHARGE
Any discharge to the MS4 that is not composed entirely of stormwater or polluted stormwater, except for discharges allowed under an NPDES permit, discharges conditionally allowed under the MS4 permit, and discharges authorized by this chapter as set forth in §
23-607.
[Added by Ord. No. 2022-06, 9/12/2022]
IMPERVIOUS SURFACE (IMPERVIOUS AREA)
Surfaces which prevent the infiltration of water into the
ground. All structures, buildings, parking areas, driveways, roads,
streets, sidewalks, decks, and any areas of concrete, asphalt, packed
stone, and compacted soil shall be considered impervious surface if
they prevent infiltration.
IMPOUNDMENT
A retention or detention facility designed to retain stormwater
runoff and infiltrate it into the ground (in the case of a retention
basin) or release it at a controlled rate (in the case of a detention
basin).
INFILTRATION STRUCTURES
A structure designed to retain stormwater runoff and infiltrate
it into the ground (in the case of a retention basin) or release it
at a controlled rate (in the case of a detention basin).
INLET
A surface connection to a closed drain. The upstream end
of any structure through which water may flow.
INTERMITTENT STREAM
A body of water flowing in a channel or bed composed primarily
of substrates associated with flowing water, which, during periods
of the year, is below the local water table and obtains its flow from
both surface runoff and groundwater discharges.
INVASIVE VEGETATION (INVASIVES)
Plants which grow quickly and aggressively, spreading, and
displacing other plants. Invasives typically are introduced into a
region far from their native habitat. See invasive plants in Pennsylvania
by the DCNR.
LAND DEVELOPMENT
An activity meeting the definition of land development in Chapter
22, "Subdivision and Land Development."
LIMITING ZONE
A rock formation, other stratum, or soil condition which
is so slowly permeable that it effectively limits downward passage
of effluent. Season high water tables, whether perched or regional,
also constitute a limiting zone.
LINEAMENT
A fracture on the order of tens of kilometers long usually
extending to the basement below sedimentary rock.
MANNING EQUATION (MANNING FORMULA)
A method for calculation of velocity of flow (e.g., feet
per second) and flow rate (e.g., cubic feet per second) in open channels
based upon channel shape, roughness, depth of flow and slope. "Open
channels" may include closed conduits so long as the flow is not under
pressure.
MPC
The Pennsylvania Municipalities Planning Code, Act of 1968,
P.L. 805, No. 247, as reenacted and amended, 53 P.S. § 10101
et seq.
MUNICIPAL SEPARATE STORM SEWER
A conveyance or system of conveyances (including roads with
drainage systems, municipal streets, catch basins, curbs, gutters,
ditches, man-made channels, or storm drains), which is all of the
following: (1) owned or operated by a state, city, town, borough,
township, county, district, association or other public body (created
under state law) having jurisdiction over disposal of sewage, industrial
wastes, stormwater or other wastes; (2) designed or used for collecting
or conveying stormwater; (3) not a combined sewer; and (4) not part
of a publicly-owned treatment works as defined at 40 CFR § 122.2.
MUNICIPAL SEPARATE STORM SEWER SYSTEM (MS4)
All separate storm sewers that are defined as "large" or
"medium" or "small" municipal separate storm sewer systems pursuant
to 40 CFR §§ 122.26(b)(18), or designated as regulated
under 40 CFR § 122.26(a)(1)(v).
NATURAL GROUND COVER
Ground cover which mimics the infiltration characteristics
of predominant hydrologic soil group found at the site.
NONPOINT SOURCE POLLUTION
Pollution that enters a body of water from diffuse origins
in the watershed and does not result from discernible, confined, or
discrete conveyances.
NRCS
National 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 drainage ways, swales, streams, ditches, canals, and
pipes flowing partly full.
OUTFALL
Point where water flows from a conduit, stream, or drain.
OUTLET
Points of water disposal from a stream, river, lake, tidewater
or artificial drain.
PARENT TRACT
All contiguous land held in single and separate ownership,
regardless of whether (1) such land is divided into one or more lots,
parcels, purparts or tracts; (2) such land was acquired by the landowner
at different times or by different deeds, devise, partition or otherwise;
or (3) such land is bisected by public or private streets or rights-of-way,
which was held by the landowner or his predecessor in title on October
19, 2003.
PARKING LOT STORAGE
Involves the use of impervious parking areas as temporary
impoundments with controlled release rates during rainstorms.
PEAK DISCHARGE
The maximum rate of flow of water at a given point and time
resulting from a specified storm event.
PENNDOT
The Pennsylvania Department of Transportation or any agency
successor thereto.
PERVIOUS AREA
Any material/surface that allows water to pass through at
a rate equal to or greater than natural ground cover.
QUALIFIED PERSON
Any person licensed by the Pennsylvania Department of State
or otherwise qualified by law to perform the work required by this
chapter.
RATE CONTROL
SWM controls used to manage the peak flows for the purposes
of channel protection and flood mitigation.
REDEVELOPMENT
Any physical improvement to a previously developed lot that
involves earthmoving, removal, or addition of impervious surfaces.
REGIONAL STORMWATER MANAGEMENT PLAN
Plan to manage stormwater runoff from an area larger than
a single development site. A regional stormwater management plan could
include two adjacent parcels, an entire watershed, or some defined
area in between. Regional stormwater management plans can be prepared
for new development, or as a retrofit to manage runoff from already
developed areas.
REGULATED ACTIVITIES
Activities, including earth disturbance activities, that
involve the alteration or development of land in a manner that may
affect stormwater runoff. Regulated activities shall include, but
not be limited to:
[Amended by Ord. No. 2022-06, 9/12/2022]
(1)
Land development subject to the requirements of Chapter
22, Subdivision and Land Development;
(2)
Removal of ground cover, grading, filling or excavation;
(3)
Construction of new or additional impervious or semi-impervious
surfaces (driveways, parking lots, etc.) and associated improvements;
(4)
Construction of new buildings or additions to existing buildings;
(5)
Installation or alteration of stormwater management facilities
and appurtenances thereto;
(6)
Diversion or piping of any watercourse;
(7)
Any other regulated activities where the Township determines
that said activities may affect any existing watercourse's stormwater
management facilities or stormwater drainage patterns; and
(8)
Any activities where the Township determines that said activities
may affect the water quality of stormwater discharges or generate
nonstormwater discharges to the MS4 and/or receiving water bodies.
RELEASE RATE
For a specific design storm or list of design storms, the
percentage of peak flow rate for existing conditions which may not
be exceeded for the proposed conditions.
RETENTION BASIN
A basin designed to retain stormwater runoff with its primary
release of water being through the infiltration of said water into
the ground.
RETURN PERIOD
The average interval, in years, within which a storm event
of a given magnitude can be expected to recur. For example, the twenty-five-year
return period rainfall would be expected to recur on the average once
every 25 years.
RIPARIAN
Pertaining to a stream, river or other watercourse. Also,
plant communities occurring in association with any spring, lake,
river, stream or creek through which waters flow at least periodically.
RIPARIAN BUFFER
A BMP that is an area of permanent vegetation along a watercourse.
RIPARIAN CORRIDOR
A strip of land, centered on a stream or river that includes
the floodplain as well as related riparian habitats adjacent to the
floodplain.
RIPARIAN FOREST BUFFER
A type of riparian buffer that consists of permanent vegetation
that is predominantly native trees, shrubs and forms along a watercourse
that is maintained in a natural state or is sustainably managed to
protect and enhance water quality, stabilize stream channels and banks,
and separate land use activities from surface waters.
ROOFTOP DETENTION
Temporary ponding and gradual release of stormwater falling
directly onto flat roof surfaces by incorporating controlled-flow
roof drains into building designs.
RUNOFF
That part of precipitation which flows over the land.
SCS
Soil Conservation Service, U.S. Department of Agriculture
(U.S.D.A.), now referred to as NRCS.
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.
SEDIMENT BASIN
A barrier, dam, retention or detention basin designed to
retain sediment.
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
material and into which stormwater runoff is directed for infiltration
into the ground.
SEMI-PERVIOUS SURFACE
A surface such as stone, rock or other materials which permits
some vertical transmission of water into the ground.
SHEET FLOW
Runoff which 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 SCS (now
NRCS) that is based on relating soil type and land use/cover to a
runoff parameter called curve number (CN).
SOIL GROUP, HYDROLOGIC
A classification of soils by the SCS (now NRCS) into four
runoff potential groups. The groups range from A soils, which are
very permeable and produce little runoff, to D soils, which are not
very permeable and produce much more runoff.
SPILLWAY
A depression in the embankment of a pond or basin which is
used to pass a post-development one-hundred-year storm peak flow rate.
STATE WATER QUALITY REQUIREMENTS
The regulatory requirements to protect, maintain, reclaim,
and restore water quality under Title 25 of the Pennsylvania Code,
the Clean Streams Law and the Clean Water Act.
STORAGE INDICATION METHOD
A reservoir routing procedure based on solution of the continuity
equation inflow minus outflow equals the change in storage, with outflow
defined as a function of storage volume and depth.
STORM FREQUENCY
The number of times that a given storm "event" occurs or
is exceeded on the average in a stated period of years. See "return
period."
STORM SEWER
A system of pipes, conduits, swales or other similar structures
including appurtenant works which carries intercepted runoff, and
other drainage, but excludes domestic sewage, industrial wastes and
other unauthorized discharges.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
STORMWATER MANAGEMENT
A program of controls and measures designed to regulate the
quantity and quality of stormwater runoff from a development while
promoting the protection and conservation of ground waters and groundwater
recharge.
STORMWATER MANAGEMENT FACILITIES
Any structure, natural or man-made, that, due to its condition,
design, or construction, conveys, stores, infiltrates/evaporates/transpires,
cleans or otherwise affects stormwater runoff. Typical SWM facilities
include, but are not limited to, detention and retention basins, open
channels, watercourses, road gutters, swales, storm sewers, pipes,
BMPs, and infiltration structures.
STORMWATER MANAGEMENT PLAN
A plan prepared by an applicant indicating how stormwater
runoff will be managed at a particular development site according
to this chapter.
STRUCTURE
Any man-made object having an ascertainable stationary location
on or in land or water, whether or not affixed to the land.
STREAM ENCLOSURE
A bridge, culvert or other structure in excess of 100 feet
in length upstream to downstream which encloses a regulated water
of this Commonwealth.
SUBDIVISION
A subdivision of land as defined in the MPC.
SUBSTRATES
Inorganic sediments which are 0.05 millimeter in diameter
or larger and include sands, gravel, pebbles, cobbles and boulders,
based upon Wentworth's classification.
SWALE
Any man-made ditch designed to convey stormwater directly
to another stormwater management facility or surface waters.
SWM
Stormwater management.
TIME OF CONCENTRATION (TC)
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 pipes or channels, if any.
TOWNSHIP
The Township of Penn, Lancaster County, Pennsylvania.
TR-20 (CALIBRATED)
The computer-based hydrologic modeling technique adapted
to the watershed in which the subject property is located by the applicable
Act 167 Plan. The model has been "calibrated" to reflect published
and observed flow values by adjusting key input model parameters.
VOLUME CONTROL
SWM controls, or BMPs, used to remove a predetermined amount
of runoff or the increase in volume between the pre- and post-development
design storm.
WATERCOURSE
A permanent or intermittent stream, river, brook, run, creek,
channel, swale, pond, lake or other body of surface water carrying
or holding surface water, whether natural or artificial.
WATERS OF THE COMMONWEALTH
Any and all rivers, streams, creeks, rivulets, 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
The entire region or area drained by a river or other body
of water, whether natural or man-made.
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, ferns, and similar areas.