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For the purposes of this chapter, certain terms and words used
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 word "includes" or "including" shall not limit the term to the
specific example but is intended to extend its meaning to all other
instances of like kind and character.
C. The words "shall" and "must" are mandatory; the words "may" and "should"
are permissive.
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 natural processes, at a rate greater
than would occur because of the natural processes alone.
- BEST MANAGEMENT PRACTICE (BMP)
- Activities, facilities, measures or procedures used to manage
stormwater quantity and quality impacts from the regulated activities
listed in § 205-5, to meet state water quality requirements,
to promote groundwater recharge and to otherwise meet the purposes
of this chapter.
- BEST MANAGEMENT PRACTICE OPERATIONS AND MAINTENANCE PLAN
- Documentation, included as part of a drainage plan, detailing
the proposed BMPs, how they will be operated and maintained and who
will be responsible.
- 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.
- A.
— A zone of variable width located along
a stream that is vegetated and is designed to filter pollutants from
runoff.
- B.
— A 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 subsurface,
for later reuse, such as for irrigation of gardens and other planted
areas. Because this stormwater is utilized and no pollutant discharge
results, water quality performance is superior to other noninfiltration
BMPs.
- 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.
- 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
- The Lehigh or Northampton County Conservation District, as
applicable.
- 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 (both 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 carefully, 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 depth and time distribution of precipitation from a storm
event measured in probability of occurrence (e.g., one-hundred-year
storm) and duration (e.g. two-hour) and used in computing stormwater
management control systems.
- DETENTION BASIN
- A basin designed to retard stormwater runoff by temporarily
storing the runoff and releasing it at the appropriate release 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 chapter.
- DEVELOPMENT SITE (SITE)
- The specific tract of land for which a regulated activity
is proposed.
- DIFFUSED DRAINAGE
- See "sheet flow."
- 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 § 205-20.
- 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 removal of soil particles by the action of water, wind,
ice, or other geological agents.
- 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).
- FILL
- Man-made deposits of natural soils or rock products and waste
materials.
- FILTER STRIPS
- See "vegetated buffers."
- FREEBOARD
- The incremental depth in a stormwater management structure,
provided as a safety factor of design, above that required to convey
the design runoff event.
- GROUNDWATER RECHARGE
- Replenishment of existing natural underground water supplies.
- HARDSHIP WAIVER REQUEST
- A written request for a waiver alleging that the provisions
of this chapter inflict unnecessary hardship upon the applicant. A
Hardship Waiver does not apply to and is not available from the water
quality provisions of this chapter 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 § 205-14P.
- HYDROLOGIC SOIL GROUP (HSG)
- Soils are classified into four HSGs (A, B, C and D) to indicate
the minimum infiltration rates, which are obtained for bare soil after
prolonged wetting. The Natural Resources Conservation Service (NRCS)
of the US 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 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.
- IMPERVIOUS SURFACE (IMPERVIOUS COVER)
- A surface which prevents the percolation of water into the
ground.
- INFILTRATION PRACTICE
- A practice designed to direct runoff into the ground, e.g.,
french drain, seepage pit, seepage trench or bioretention area.
- KARST
- A type of topography or landscape characterized by depressions,
sinkholes, limestone towers and steep-sided hills, underground drainage
and caves. Karst is usually formed on carbonate rocks, such as limestones
or dolomites and sometimes gypsum.
- 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; or
- (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.
- B.
- C.
Development in accordance with Section 503(1.1) of the Pennsylvania
Municipalities Planning Code.
- LOADING RATE
- The ratio of the land area draining to the system, as modified
by the weighting factors in § 205-17B, compared to the base
area of the infiltration system.
- LOCAL RUNOFF CONVEYANCE FACILITIES
- Any natural channel or man-made conveyance system which has
the purpose of transporting runoff from the site to the mainstem.
- LOW-IMPACT DEVELOPMENT
- A development approach that promotes practices that will
minimize post-development runoff rates and volumes thereby minimizing
needs for artificial conveyance and storage facilities. Site design
practices include preserving natural drainage features, minimizing
impervious surface area, reducing the hydraulic connectivity of impervious
surfaces and protecting natural depression storage.
- MAINSTEM (MAIN CHANNEL)
- Any stream segment or other conveyance used as a reach in
the Bushkill 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. As of
January 2004, the Manual can be obtained through the following web
site: 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 also 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 Stockertown, Northampton County, Pennsylvania.
- NO HARM 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
- Natural Resources Conservation Service, US Department of
Agriculture. (Formerly the Soil Conservation Service.)
- 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 surface 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.
- PENN STATE RUNOFF MODEL (PSRM)
- The computer-based hydrologic modeling technique adapted
to each watershed for the Act 167 Plans. The model was calibrated
to reflect actual flow values by adjusting key model input parameters.
- 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.
- PRELIMINARY SITE INVESTIGATION
- The determination of the depth to bedrock, the depth to the
seasonal high water 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.
- PUBLIC WATER SUPPLIER
- A person who owns or operates a public water system.
- 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 GEOTECHNICAL PROFESSIONAL
- A licensed professional geologist or a licensed professional
engineer who has a background or expertise in geology or hydrogeology.
- RATIONAL METHOD
- A method of peak 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
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
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