As used in this chapter, the following terms shall have the
meanings indicated:
ACCELERATED EROSION
The removal of the surface of the land through the combined
action of human activities and the natural processes at a rate greater
than would occur because of the natural process alone.
ACT 167
The Stormwater Management Act, Act of October 4, 1978, P.L.
864, No. 167, as amended by the Act of May 24, 1984, No. 63, 32 P.S.
§ 680.1 et seq. The Borough is empowered to regulate land
use activities that affect runoff and surface and groundwater quality
and quantity by the authority of the Act, the "Storm Water Management
Act."
AGRICULTURAL ACTIVITY
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. Except for high tunnels that are exempt pursuant to the
provisions of Act 15 of 2018, construction of new buildings or impervious
areas is not considered an agricultural activity.
ANIMAL CONCENTRATION (HEAVY USE) AREAS
A barnyard, feedlot, loafing area, exercise lots, or other
similar animal confinement areas that will not maintain a growing
crop, or where deposited manure nitrogen is in excess of crop needs,
but excluding areas managed as pastures or other cropland, and pasture
accessways, if they do not cause direct flow of nutrients to surface
water or groundwater.
APPLICANT
A landowner, developer or other person who has filed an application
for development or for approval to engage in any regulated earth disturbance
activity at a project site in the Borough.
BMP (BEST MANAGEMENT PRACTICE)
Activities, facilities, designs, measures or procedures used
to manage stormwater impacts from regulated development activities,
to meet state water quality requirements, to promote groundwater recharge
and to otherwise meet the purposes of this chapter. BMPs include,
but are not limited to, infiltration, filter strips, low-impact design,
bioretention, wet ponds, permeable paving, grassed swales, forested
buffers, sand filters and detention basins.
CHANNEL
A perceptible natural or artificial waterway which periodically
or continuously contains moving water or which forms a connecting
link between two bodies of water. It has a definite bed and banks
which confine the water.
CHAPTER 102
Title 25 Pa. Code Chapter 102, Erosion and Sedimentation
Control.
CHAPTER 105
Title 25 Pa. Code Chapter 105, Dam Safety and Waterway Management.
CONSERVATION DISTRICT
The Westmoreland Conservation District (WCD), 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
PADEP to administer and enforce all or a portion of the regulations
promulgated under 25 Pa. Code Chapter 102.
CONSERVATION PLAN
A plan written by an NRCS or SCS certified planner that identifies
conservation practices and includes site-specific BMPs for agricultural
plowing or tilling activities and animal concentration 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
A.
Any structure that carries a flow.
B.
The ability of a pipe, culvert, swale or similar facility to
carry the peak flow from the design storm.
CSO, COMBINED SEWER OVERFLOW
An intermittent flow or other untreated discharge from a
municipal combined sewer system (including domestic, industrial and
commercial wastewater and stormwater) which results from a flow in
excess of the dry weather carrying capacity of the system.
CULVERT
A closed conduit for the free passage of surface drainage
under a highway, railroad, canal or other embankment.
DEMONSTRATED EQUIVALENCY
A stormwater management project on an alternative site(s)
within the same watershed as the proposed development that will provide
equal or better achievement of the purpose of the chapter and will
not substantially or permanently impair the appropriate use or development
of adjacent property. Examples include stream bank stabilization,
creation or enhancement of riparian buffers, removal of existing impervious
surfaces and establishment of "green" easements, installation of stormwater
management and water quality facilities, etc.
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 of its intended functions.
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 in a detention basin or within the
drainage system.
DETENTION BASIN
A pond, basin, reservoir or underground system constructed
to impound or retard surface runoff temporarily.
DEVELOPER
A person that seeks to undertake or undertakes the activities
associated with changes in land use or seeks to undertake or undertakes
any regulated earth disturbance activities at a project site in the
Borough. The term "developer" includes, but is not limited to, the
term subdivider, owner, builder or another person with a similar interest
in the project, even though the person involved in successive stages
of a project may change or vary.
DEVELOPMENT
An "earth disturbance activity," as herein defined and any
activity, construction, alteration, change in land use or practice
that affects stormwater runoff characteristics. The term also includes
redevelopment.
DEVELOPMENT SITE
The specific tract of land where any development or earth
disturbance activities in the Borough are planned, conducted, undertaken
or maintained.
DISCHARGE
The flow or rate of flow from a canal, conduit, channel or
other hydraulic structure.
DISTURBED AREA
A land area where an earth disturbance activity is occurring
or has occurred.
DRAINAGE
In general, the removal of surface water from a given area
commonly applied to surface water and groundwater.
DRAINAGE AREA
Any of the following activities:
A.
The area of a drainage basin or watershed, expressed in acres,
square miles or other unit of area (also called "catchment area,"
"watershed," "river basin").
B.
The area served by a sewer system receiving stormwater and surface
water, or by a watercourse.
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, land development,
building construction, oil and gas activities, well drilling, mineral
extraction, and the moving, depositing, stockpiling, or storing of
soil, rock or earth materials.
ENCROACHMENT
Any structure or activity which in any manner changes, expands
or diminishes, the course, current or cross section of any watercourse,
floodway or body of water.
EROSION
The process by which land, including channels, is worn away
by water, wind, or chemical action.
EROSION CONTROL
The application of measures to reduce erosion of land surfaces.
EXISTING CONDITION
The dominant land cover during the five-year period immediately
preceding a proposed regulated activity.
FEMA
Federal Emergency Management Agency.
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 PADEP Technical Manual
for Sewage Enforcement Officers (as amended or replaced from time
to time by PADEP).
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.
GREEN INFRASTRUCTURE
Systems and practices that use or mimic natural processes
to infiltrate, evapotranspire, or reuse stormwater on the site where
it is generated.
GROUND COVER
Materials and/or vegetation covering the ground surface.
GROUNDWATER
Subsurface water occupying the saturation zone, from which
wells and springs are fed.
HIGH TUNNEL
A structure which meets the following:
A.
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 Forestland Assessment Act of 1974, or for the storage of agricultural equipment and supplies.
B.
Is constructed consistent with all of the following:
(1)
Has metal, wood or plastic frame.
(2)
When covered, has plastic, woven textile or other flexible covering.
(3)
Has a floor made of soil, crushed stone, matting, pavers or
a floating concrete slab.
HOT SPOTS
Areas where land use or activities generate highly contaminated
runoff, with concentrations of pollutants that are higher than those
typically found in stormwater (e.g., vehicle salvage yards and recycling
facilities, vehicle fueling stations, fleet storage areas, vehicle
equipment and cleaning facilities, vehicle service and maintenance
facilities, and certain industrial/commercial activity areas).
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 permeable as the
HSG varies from A to D (NRCS 1,2).
IMPERVIOUS SURFACE
A surface that prevents the infiltration of water into the
ground. Impervious surfaces (or areas) shall include, but not be limited
to: roofs, additional indoor living spaces, patios, garages, storage
sheds, and similar structures; and any new streets or sidewalks. Decks,
parking areas, gravel areas, and driveway areas are counted as impervious
areas if they directly prevent infiltration.
INFILTRATION
Any of the following activities:
A.
The flow or movement of water through the interstices or pores
of a soil or other porous medium.
B.
The absorption of liquid by the soil.
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.
LAND DISTURBANCE
Any activity involving the changing, grading, transportation,
fill and any other activity which causes land to be exposed to the
danger of erosion.
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.
MAINTENANCE
The upkeep necessary for efficient operation of physical
properties.
MS4 (MUNICIPAL 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):
A.
Owned or operated by a state, city, town, borough, county, parish,
district, association, authority or other public body (created by
or pursuant to state law), including special districts under state
law such as a sewer district, flood control district or drainage district,
or similar entity, or an Indian tribe or an authorized Indian tribal
organization, or a designated and approved management agency under
Section 208 of the Clean Water Act that discharges into waters of
the United States;
B.
Designed or used for collecting or conveying stormwater;
C.
Which is not a combined sewer; and
D.
Which is not part of a publicly owned treatment works (POTW)
as defined at 40 CFR 122.2.
MUNICIPALITY
Borough of Derry, Westmoreland County, Pennsylvania.
NATIVE VEGETATION
Plant species that have historically grown in Pennsylvania
and are not invasive species, controlled plants or noxious weeds as
defined by PA DCNR, or Pennsylvania Department of Agriculture.
NATURAL STORMWATER RUNOFF REGIME
A watershed where natural surface configurations, runoff
characteristics and defined drainage conveyances have attained the
conditions of equilibrium.
NPDES
National Pollutant Discharge Elimination System, the federal
government's system for issuance of permits under the Clean Water
Act, which is delegated to PADEP in Pennsylvania.
NRCS
Natural Resources Conservation Service (previously Soil Conservation
Service).
OUTFALL
"Point source" as described in 40 CFR 122.2 at the point
where the Borough storm sewer system discharges to surface waters
of the commonwealth. Also, the point, location or structure where
drainage discharges from a sewer, drain or other conduit as well as
the conduit leading to the ultimate discharge point.
OUTLET CONTROL STRUCTURE
The means of controlling the relationship between the head
water elevation and the discharge, placed at the outlet or downstream
end of any structure through which water may flow.
OVERLAND FLOODING
Flooding that occurs for a variety of reasons all stemming
from excessive stormwater runoff including too much rain in too little
time, added impervious development, change in land use, malfunction
or clogging of existing stormwater systems.
PADEP
The Pennsylvania Department of Environmental Protection.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specific storm
event.
PERFORMANCE STANDARD
A standard which establishes an end result or outcome which
is to be achieved but does not prescribe specific means for achieving
it.
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. Whenever used in any section
prescribing or imposing a penalty, the term "person" shall include
the members of a partnership, the officers, members, servants and
agents of an association, officers, agents and servants of a corporation,
and the officers of a municipality or county, but shall exclude any
department, board, bureau or agency of the commonwealth.
PERVIOUS AREA
Any material or surface that allows water to pass through
at a rate equal to or greater than natural ground cover.
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.
POLLUTANT REDUCTION PLAN (PRP)
A plan required by the MS4 permit to calculate existing pollutants
of concern and the minimum reduction in loading from stormwater discharges,
and to select the best management practices to achieve the minimum
reductions.
PROJECT SITE
The specific area of land where any development or regulated
earth disturbance activities in the Borough are planned, conducted,
undertaken or maintained.
QUALIFIED PROFESSIONAL
Any person licensed by the Pennsylvania Department of State
or otherwise qualified under Pennsylvania law to perform the work
required by this chapter.
RECORD DRAWINGS
Drawings showing the stormwater management system of a site
as built, created after the completion of construction and intended
for use as a permanent record of the stormwater management system.
REDEVELOPMENT
Earth disturbance activities on land which has previously
been disturbed or developed.
REGULATED DEVELOPMENT ACTIVITY
Any earth disturbance activities or any activities that involve the change of land cover, alteration or development of land in a manner that may affect stormwater runoff as listed in the Regulated Development Activity Table. This includes earth disturbance on any portion of, part, or during any stage of, a larger common plan of development. With regard to road maintenance activities the term only includes activities involving one acre or more or earth disturbance. Refer to the Regulated Development Activity Table in Article
III of this chapter.
RELEASE RATE
The percentage of existing conditions peak rate of runoff
from a site or subarea to which the proposed conditions peak rate
of runoff must be reduced to protect downstream areas.
RELEASE RATE PERCENTAGE
The watershed factor determined by comparing the maximum
rate of runoff from a subbasin to the contributing rate of runoff
to the watershed peak rate at specific points of interest.
RESOURCE EXTRACTION
Any activity that involves withdrawing materials from the
natural environment.
RETENTION BASIN
A pond, basin, usually enclosed by artificial dikes, that
is used to retard stormwater runoff by temporarily storing the runoff
and releasing it at a predetermined rate.
RETENTION VOLUME/REMOVED RUNOFF
The volume of runoff that is captured and not released directly
into the surface waters of this commonwealth during or immediately
after a storm event.
RETURN PERIOD
The average interval in years over which an event of a given
magnitude can be expected to recur.
RIPARIAN BUFFER
A permanent area of native vegetation including herbaceous
material, shrubs and/or trees 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
That part of precipitation which flows over the land.
RUNOFF CHARACTERISTICS
The surface components of any watershed which affect the
rate, amount and direction of stormwater runoff. These may include,
but are not limited to, vegetation, soils, slopes and man-made landscape
alterations.
RURAL AREA
All population, housing and territory not included within
an urban, or urbanized, area as determined from the latest United
States Census Bureau data.
SALDO
Subdivision and land development ordinance.
SEDIMENT
Mineral or organic solid material that is being transported
or has been moved from its site of origin by air, water or ice and
has come to rest.
SEDIMENTATION
The process by which mineral or organic matter is accumulated
or deposited by moving water, wind or gravity.
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. Refer to MS4.
SMALL PROJECT
Regulated development activities that, measured on a cumulative
basis from five years prior to the application, create additional
impervious areas of more than 500 square feet and less than 2,000
square feet or involve earth disturbance activity of an area less
than 4,000 square feet and do not involve the alteration of stormwater
facilities or watercourses.
STATE WATER QUALITY REQUIREMENTS
As defined under state regulations, protection of designated
and existing uses (See 25 Pa. Code, Chapters 93 and 96), including:
A.
Each stream segment in Pennsylvania has a "designated use,"
such as "cold water fishery" or "potable water supply," which are
listed in 25 Pa. Code Chapter 93. These uses must be protected and
maintained, under state regulations.
B.
"Existing uses" are those attained as of November 1975, regardless
whether they have been designated in 25 Pa. Code Chapter 93. Regulated
earth disturbance activities must be designed to protect and maintain
existing uses and maintain the level of water quality necessary to
protect those uses in all streams, and to protect and maintain water
quality in special protection streams.
C.
Water quality involves the chemical, biological and physical
characteristics of surface water bodies. After regulated earth disturbance
activities are complete, these characteristics can be impacted by
addition of pollutants such as sediment, and changes in habitat through
increased flow volumes and/or rates as a result of changes in land
surface area from those activities. Therefore, permanent discharges
to surface waters must be managed to protect the stream bank, streambed
and structural integrity of the waterway, to prevent these impacts.
STORAGE FACILITY
Any surface or subsurface facility that stores stormwater
runoff; see "detention basin" and "retention basin."
STORM FREQUENCY
The average interval in years over which a storm event of
a given precipitation volume can be expected to occur. The magnitude
and temporal distribution of precipitation from a storm event measured
in probability of occurrence (e.g., a five-year storm) and duration
(e.g., 24 hours) used in the design and evaluation of stormwater management
systems. Also see "return period."
STORM SEWER
A sewer that carries intercepted surface runoff, street water
and other drainage but excludes domestic sewage and industrial waste.
STORMWATER
Drainage runoff from the surface of the land resulting from
precipitation or snow or ice melt.
STORMWATER COLLECTION SYSTEMS
Natural or man-made structures that collect and transport
stormwater through or from a drainage area to the point of final outlet
including, but not limited to, any of the following conduits and appurtenant
features, canals, channels, ditches, streams, culverts, streets and
pumping stations.
STORMWATER MANAGEMENT PLAN
The plan for managing stormwater runoff rate, volume and
water quality as required by the Stormwater Management Act, 32 P.S.
§ 680.1 et seq.
SUBDIVISION
As defined in the Pennsylvania Municipalities Planning Code,
Act of July 31, 1968, P.L. 805, No. 247, as amended.
SWALE
A low-lying stretch of land which gathers or carries surface
water runoff.
URBAN OR URBANIZED AREA
Area that is densely populated and/or is significantly built
upon with buildings, pavement, and other man-made features. Urban
(or urbanized) areas are defined in the latest United States Census
Bureau data.
USDA
United States Department of Agriculture.
WATERCOURSE
A channel or conveyance of surface water, such as a run,
stream or creek, having defined bed and banks, whether natural or
artificial, with perennial or intermittent flow.
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 this commonwealth.
WATERSHED
The entire region or area drained by a river or other body
of water whether natural or artificial. A "designated watershed" is
an area delineated by the PADEP and approved by the Environmental
Quality Board for which counties are required to develop watershed
stormwater management plans.
WATERSHED STORMWATER MANAGEMENT PLAN
The plan for managing stormwater runoff throughout a designated
watershed as required by the Pennsylvania Stormwater Management Act
(Act 167), 32 P.S. § 680.1 et seq.
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.