These definitions do not necessarily reflect the definitions contained
in pertinent regulations or statues and are intended for this Part
only.
ACCELERATED EROSION
The removal of the surface of the land through the combined
action of human activities and natural processes, at a rate greater
than would occur because of the natural processes alone.
AGRICULTURAL ACTIVITY
Activities associated with agriculture such as agricultural
cultivation, agricultural operation, and animal heavy use areas. This
includes the work of producing crops, including tillage, land clearing,
plowing, disking, harrowing, planting, 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 to the Borough for approval to engage in any regulated
activity at a project site in the Borough.
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 Part. Stormwater BMPs are
commonly grouped into one of two broad categories or measures: "structural"
or "nonstructural." In this Part, 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.
BIORETENTION
Densely vegetated, depressed features that store stormwater
and filter it through vegetation, mulch, planting soil, etc. Ultimately
stormwater is evapotranspirated, infiltrated, or discharged. Optimal
bioretention areas mimic natural forest ecosystems in terms of species
diversity, density, distribution, use of native plants, etc.
BUFFER
(1)
STREAMSIDE BUFFERA zone of variable width located along a stream that is vegetated and is designed to filter pollutants from runoff.
(2)
SPECIAL GEOLOGIC FEATURE BUFFERA required isolation distance from a special geologic feature to a proposed BMP needed to reduce the risk of sinkhole formation due to stormwater management activities.
CAPTURE/REUSE
Stormwater management techniques such as cisterns and rain
barrels which direct runoff into storage devices, surface or sub-surface,
for later reuse, such as for irrigation of gardens and other planted
areas.
CARBONATE BEDROCK
Rock consisting chiefly of carbonate minerals, such as limestone
and dolomite; specifically, a sedimentary rock composed of more than
50% by weight of carbonate minerals that underlies soil or other unconsolidated,
superficial material.
CATASAUQUA CREEK STUDY AREA
The area comprised of the Catasauqua Creek Watershed and
Lehigh River Subbasin 4 (six unnamed creeks and 27 direct drainage
subareas). See map in Appendix A.
CISTERN
An underground reservoir or tank for storing rainwater.
CLOSED DEPRESSION
A distinctive bowl-shaped depression in the land surface.
It is characterized by internal drainage, varying magnitude and an
unbroken ground surface.
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 DEP to administer
and enforce all or a portion of the regulations promulgated under
25 Pa. Code 102.
CONSTRUCTED WETLANDS
Constructed wetlands are similar to wet ponds (see below)
and consist of a basin which provides for necessary stormwater storage
as well as a permanent pool or water level, planted with wetland vegetation.
To be successful, constructed wetlands must have adequate natural
hydrology (runoff inputs as well as soils and water table which allow
for maintenance of a permanent pool of water). In these cases, the
permanent pool must be designed care-fully, usually with shallow edge
benches, so that water levels are appropriate to support carefully
selected wetland vegetation.
CULVERT
A pipe, conduit or similar structure, including appurtenant
works, which carries surface water.
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.
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
twenty-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
A basin designed to retard stormwater runoff by temporarily
storing the runoff and releasing it at a predetermined rate.
DETENTION VOLUME
The volume of runoff that is captured and released into the
waters of the Commonwealth at a controlled rate.
DEVELOPER
A person, partnership, association, corporation or other
entity, or any responsible person therein or agent thereof, that undertakes
any regulated activity of this Part.
DIRECT RECHARGE/SUBSURFACE BMP
A BMP designed to direct runoff to groundwater recharge without
providing for vegetative uptake. Examples include infiltration trenches,
seepage beds, drywells and stormwater drainage wells such that nearly
all runoff becomes recharge to groundwater.
DISTURBED AREA
An unstabilized land area where an earth disturbance activity
is occurring or has occurred.
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 proposed stormwater quantity and
quality management controls to be used for a given development site,
including a BMP operations and maintenance plan, the contents of which
are established in § 143.
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; road maintenance; building construction;
and the moving, depositing, stockpiling, or storing of soil, rock,
or earth materials.
EROSION
The natural process by which the surface of the land is worn
away by water, wind, or chemical action.
EXISTING CONDITION
The dominant land cover during the five-year period immediately
preceding a proposed regulated activity.
EXISTING USES
Those uses actually attained in the water body on or after
November 28, 1975, whether or not they are included in the water quality
standards. (25 Pa. Code Chapter 93.1)
FEMA
Federal Emergency Management Agency.
FILL
Man-made deposits of natural soils or rock products and waste
materials.
FLOODPLAIN
Any 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. 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).
FLOODWAY
The channel of the watercourse and those portions of the
adjoining floodplains that are reasonably required to carry and discharge
the 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 100-year floodway, it is assumed, absent evidence
to the contrary that the floodway extends from the stream to 50 feet
from the top of the bank of the stream.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forestland.
These include conducting a timber inventory, preparation of forest
management plans, silvicultural treatment, cutting budgets, logging
road design and construction, timber harvesting, site preparation,
and reforestation.
FREEBOARD
The incremental depth in a stormwater management structure,
provided as a safety factor of design, above that required to convey
the design runoff events.
GREEN INFRASTRUCTURE
Systems and practices that use or mimic natural processes
to infiltrate, evapotranspire, or reuse stormwater on the site where
it is generated.
HARDSHIP WAIVER REQUEST
A written request for a waiver alleging that the provisions
of this Part inflict unnecessary hardship upon the applicant. A hardship
waiver does not apply to and is not available from the water quality
provisions of this Part and should not be granted.
HOT SPOT LAND USES
A land use or activity that generates higher concentrations
of hydrocarbons, trace metals or other toxic substances than typically
found in stormwater runoff. These land uses are listed in Appendix
H.
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 NRCS 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 (NRCS).
INFILTRATION PRACTICE
A practice designed to allow runoff an opportunity to infiltrate
into the ground (e.g., French drain, seepage pit, seepage trench or
bioretention area).
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: i) the
improvement of one lot or two or more contiguous lots, tracts, or
parcels of land for any purpose involving a) a group of two or more
buildings or b) 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; ii) any subdivision of land; iii)
development in accordance with § 503(1.1) of the PA Municipalities
Planning Code.
LOADING RATE
The ratio of the land area draining to the system, as modified
by the weighting factors in § 128, Subsection 2 compared
to the base area of the infiltration system.
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.
MAINSTEM (MAIN CHANNEL)
Any stream segment or other conveyance used as a reach in
the Catasauqua Creek hydrologic model.
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.
MARYLAND STORMWATER DESIGN MANUAL
A stormwater design manual written by the Maryland Department
of the Environment and the Center for Watershed Protection. The Manual
can be obtained through the following website: www.mde.state.md.us.
MINIMUM DISTURBANCE/MINIMUM MAINTENANCE PRACTICES (MD/MM)
Site design practices in which careful limits are placed
on site clearance prior to development allowing for maximum retention
of existing vegetation (woodlands and other), minimum disturbance
and compaction of existing soil mantle and minimum site application
of chemicals post-development. Typically, MD/MM includes disturbance
setback criteria from buildings as well as related site improvements
such as walkways, driveways, roadways, and any other improvements.
These criteria may vary by community context as well as by type of
development being proposed. Additionally, MD/MM shall include provisions
(e.g., deed restrictions, conservation easements) to protect these
areas from future disturbance and from application of fertilizers,
pesticides and herbicides.
MUNICIPALITY
Borough of Fountain Hill, Lehigh County, Pennsylvania.
NO HARM RUNOFF QUANTITY OPTION
The option of using a less restrictive runoff quantity control
if it can be shown that adequate and safe runoff conveyance exists
and that the less restrictive control would not adversely affect health,
safety and property.
NPDES
National Pollutant Discharge Elimination System.
NRCS
USDA Natural Resources Conservation Service (previously SCS).
OIL/WATER SEPARATOR
A structural mechanism designed to remove free oil and grease
(and possibly solids) from stormwater runoff.
OUTFALL
"Point source" as described in 40 CFR § 122.2 at
the point where the municipality's storm sewer system discharges
to waters of the Commonwealth.
OWNER
One with an interest in and often dominion over a property.
PEAK DISCHARGE
The maximum rate of flow of stormwater runoff at a given
location and time resulting from a specified storm event.
PERSON
An individual, partnership, public or private association
or corporation, firm, trust, estate, municipality, governmental unit,
public utility or any other legal entity whatsoever which is recognized
by law as the subject of rights and duties.
POINT SOURCE
Any discernible, confined and discrete conveyance, including,
but not limited to, any pipe, ditch, channel, tunnel or conduit from
which stormwater is or may be discharged, as defined in state regulations
at 25 Pa. Code § 92.1.
PRE-TREATMENT
Measures implemented for hot spot land uses designed to reduce
the concentration of hydrocarbons, trace metals and other toxic substances
to levels typically found in stormwater runoff.
PRELIMINARY SITE INVESTIGATION
The determination of the depth to bedrock, the depth to the
seasonal highwater table and the soil permeability for a possible
infiltration location on a site through the use of published data
and on-site surveys. In carbonate bedrock areas, the location of special
geologic features must also be determined along with the associated
buffer distance to the possible infiltration area. See Appendix G.
PROJECT SITE
The specific area of land where any regulated activities
in the municipality are planned, conducted, or maintained.
PUBLIC WATER SYSTEM
A system which provides water to the public for human consumption,
which has at least 15 service connections or regularly serves an average
of at least 25 individuals daily at least 60 days out of the year.
(See 25 Pa. Code Chapter 109.)
QUALIFIED PROFESSIONAL
Any person licensed by the Pennsylvania Department of State
or otherwise qualified by law to perform the work required by this
Part.
RATIONAL METHOD
A method of runoff calculation using a standardized runoff
coefficient (rational 'c'), acreage of tract and rainfall
intensity determined by return period and by the time necessary for
the entire tract to contribute runoff. The rational method formula
for peak rate calculation is stated as follows: Q = ciA, where "Q"
is the calculated peak flow rate in cubic feet per second, "c" is
the dimensionless runoff coefficient (see Appendix C), "i" is the rainfall intensity in inches per hour, and
"A" is the area of the tract in acres. The rational method formula
for runoff volume calculation is as follows: V = cPA/12 where "c"
and "A" are as noted above, "P" is the total depth of precipitation
for the design event in inches, and "V" is the total runoff volume
in acre-feet.
REACH
Any of the natural or man-made runoff conveyance channels
used for watershed runoff modeling purposes to connect the subareas
and transport flows downstream.
REGULATED ACTIVITIES
Any earth disturbance activities or any activities that involve
the alteration or development of land in a manner that may affect
stormwater runoff.
RELEASE RATE
The percentage of the pre-development peak rate of runoff
for a development site to which the postdevelopment peak rate of runoff
must be controlled to avoid peak flow increases throughout the watershed.
RETENTION VOLUME/REMOVED RUNOFF
The volume of runoff that is captured and not released directly
into the surface waters of this Commonwealth during or after a storm
event.
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; or stated in another way, the probability
of a twenty-five-year storm occurring in any one year is 0.04 (i.e.,
a 4% chance).
RIPARIAN BUFFER
A permanent area of trees and shrubs located adjacent to
streams, lakes, ponds and wetlands.
ROAD MAINTENANCE
Earth disturbance activities within the existing road cross-section
such as grading and repairing existing unpaved road surfaces, cutting
road banks, cleaning or clearing drainage ditches and other similar
activities.
RUNOFF
Any part of precipitation which flows over the land.
SEDIMENT
Soils or other materials transported by surface water as
a produce of erosion.
SEDIMENT TRAPS/CATCH BASIN SUMPS
Chambers which provide storage below the outlet in a storm
inlet to collect sediment, debris, and associated pollutants typically
requiring periodic cleanout.
SEEPAGE PIT/SEEPAGE TRENCH
An area of excavated earth filled with loose stone or similar
material and into which surface water is directed for infiltration
into the ground.
SEPARATE STORM SEWER SYSTEM
A conveyance or system of conveyances (including roads with
drainage systems, municipal streets, catch basins, curbs, gutters,
ditches, man-made channels or storm drains) primarily used for collecting
and conveying stormwater runoff.
SHEET FLOW
Stormwater runoff flowing in a thin layer over the ground
surface.
SOIL COVER COMPLEX METHOD
A method of runoff computation developed by NRCS which is
based upon relating soil type and land use/cover to a runoff parameter
called a curve number.
SPECIAL GEOLOGIC FEATURES
Carbonate bedrock features, including but not limited to
closed depressions, existing sinkholes, fracture traces, lineaments,
joints, faults, caves, pinnacles, and geologic contacts between carbonate
and noncarbonate bedrock which may exist and must be identified on
a site when stormwater management BMPs are being considered.
SPILL PREVENTION AND RESPONSE PROGRAM
A program that identifies procedures for preventing and,
as needed, cleaning up potential spills and makes such procedures
known and the necessary equipment available to appropriate personnel.
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 Streams Law.
STORAGE INDICATION METHOD
A method of routing or moving an inflow hydrograph through
a reservoir or detention structure. The method solves the mass conservation
equation to determine an outflow hydrograph as it leaves the storage
facility.
STORM DRAINAGE PROBLEM AREAS
Areas which lack adequate stormwater collection and/or conveyance
facilities and which present a hazard to persons or property. These
areas are either documented in Appendix B or identified by the Borough or Borough Engineer.
STORM SEWER
A system of pipes or other conduits which carries intercepted
surface runoff, street water and other wash waters, or drainage, but
excludes domestic sewage and industrial wastes.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
STORMWATER DRAINAGE WELLS
Wells for injection of stormwater to the subsurface that
are regulated by the U.S. Environmental Protection Agency to protect
underground sources of drinking water.
STORMWATER FILTERS
Any number of structural mechanisms such as multi-chamber
catch basins, sand/peat filters, sand filters, and so forth which
are installed to intercept stormwater flow and remove pollutants prior
to discharge. Typically, these systems require periodic maintenance
and clean out.
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 facilities.
STORMWATER MANAGEMENT PLAN
The plan for managing stormwater runoff adopted by Lehigh
and/or Northampton County for the applicable watershed as required
by the Act of October 4, 1978, P.L. 864, (Act 167), as amended, and
known as the "Stormwater Management Act."
SUBAREA
The smallest unit of watershed breakdown for hydrologic modeling
purposes for which the runoff control 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 ten acres, not involving and new
street or easement of access or any residential dwelling, shall be
exempted, as defined in The Pennsylvania Municipalities Planning Code,
Act of July 31, 1968, P.L. 805, No. 247.
SURFACE WATERS
Perennial and intermittent streams, rivers, lakes, reservoirs,
ponds, wetlands, springs, natural seeps and estuaries, excluding water
at facilities approved for wastewater treatment such as wastewater
treatment impoundments, cooling water ponds and constructed wetlands
used as part of a wastewater treatment process.
SWALE
A low-lying stretch of land which gathers or carries surface
water runoff. See also "vegetated swale."
TIMBER HARVESTING ACTIVITIES
Earth disturbance activities, including the construction
of skid trails, logging roads, landing areas and other similar logging
or silvicultural practices.
TRASH/DEBRIS COLLECTORS
Racks, screens or other similar devices in- stalled in a
storm drainage system to capture coarse pollutants (trash, leaves,
etc.).
USDA
United States Department of Agriculture.
VEGETATED BUFFERS
Gently sloping areas that convey stormwater as sheet flow
over a broad, densely vegetated earthen area, possibly coupled with
the use of level spreading devices. As water quality BMPs, vegetated
buffers serve to filter pollutants from runoff and promote infiltration.
Vegetated buffers should be situated on minimally disturbed soils,
have low-flow velocities and extended residence times. Vegetated buffers
may be, but are not restricted to, use in riparian (streamside) conditions.
VEGETATED ROOFS
Vegetated systems installed on roofs that generally consist
of a waterproof layer, a root-barrier, drainage layer (optional),
growth media, and suitable vegetation. Vegetated roofs store and eventually
evapotranspirate the collected rooftop rainfall; overflows may be
provided for larger storms.
VEGETATED SWALES
Vegetated earthen channels designed to convey and possibly
treat stormwater. As water quality BMPs, these are broad, shallow,
densely vegetated, earthen channels designed to treat stormwater through
infiltration, evapotranspiration, and sedimentation. Swales should
be gently sloping with low flow velocities to prevent erosion. Check
dams may be added to enhance performance.
VEGETATED/SURFACE BMP
A BMP designed to provide vegetative uptake and soil renovation
or surface infiltration of runoff. Capture/reuse BMPs are included
if the captured runoff is applied to vegetated areas. Examples include
bioretention and surface infiltration basins.
WATER QUALITY INSERTS
Any number of commercially available devices that are inserted
into storm inlets to capture sediment, oil, grease, metals, trash,
debris, etc.
WATERCOURSE
Any channel or conveyance of surface water having a defined
bed and banks, whether natural or artificial, with perennial or intermittent
flow.
WATERS OF THIS 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
Region or area drained by a river, watercourse, or other
surface water of this Commonwealth.
WET DETENTION PONDS
Basins that provide for necessary stormwater storage as well
as a permanent pool of water. To be successful, wet ponds must have
adequate natural hydrology (both runoff inputs as well as soils and
water table which allow for maintenance of a permanent pool of water)
and must be able to support a healthy aquatic community so as to avoid
creation of mosquito and other health and nuisance problems.
WETLAND
Areas that are inundated or saturated by surface 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, and similar areas.