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 word "person" includes an individual, partnership, public or private association or corporation, firm, trust, estate, Township, 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 Township.
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."
F. 
The definitions in this chapter are for the purposes of enforcing the provisions of this chapter and have no bearing on other municipal regulations or ordinances.
As used in this chapter, the following terms shall have the meanings indicated:
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, plowing, disking, harrowing, planting or 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 Township for approval to engage in any regulated activity as defined in this chapter.
AS-BUILT PLANS (DRAWINGS)
Engineering or site plans or drawings that document the actual locations, dimensions and elevations of the improvements, and building components, and changes made to the original design plans. The final version of these documents, or a copy of same, are signed and sealed by a qualified licensed professional and submitted to the Township at the completion of the project, as per the requirements of § 158-32 of this chapter as "final as-built plans."
BANKFULL
The channel at the top-of-bank or point from where water begins to overflow onto a floodplain.
BASE FLOW
Portion of stream discharge derived from groundwater; the sustained discharge that does not result from direct runoff or from water diversions, reservoir releases, piped discharges, or other human activities.
BMP (BEST MANAGEMENT PRACTICE)
Activities, facilities, designs, measures, or procedures used to manage stormwater impacts from regulated activities, to provide water quality treatment, infiltration, volume reduction, and/or peak rate control, to promote groundwater recharge, and to otherwise meet the purposes of this chapter. Stormwater BMPs are commonly grouped into one of two broad categories or measures, "structural" or "nonstructural." In this chapter, 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 site.
BUFFER
See "riparian buffer."
CARBONATE GEOLOGY (or CARBONATE ROCK FORMATIONS)
See "karst."
cfs
Cubic feet per second.
CHANNEL
A natural or artificial open drainage feature that conveys, continuously or periodically, flowing water and through which stormwater flows. Channels include, but shall not be limited to, natural and man-made drainageways, swales, streams, ditches, canals, and pipes flowing partly full.
CN
Curve number.
COMMONWEALTH
Commonwealth of Pennsylvania.
CONSERVATION DISTRICT
The Chester County Conservation District.
CONSERVATION PLAN
A plan written by a planner certified by NRCS 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
A natural or man-made, existing or proposed facility, feature or channel used for the transportation or transmission of stormwater from one place to another. For the purposes of this chapter, "conveyance" shall include pipes, drainage ditches, channels and swales (vegetated and other), gutters, stream channels, and like facilities or features.
DESIGN STORM
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."
DETENTION (or TO DETAIN)
Capture and temporary storage of runoff in a stormwater management facility for release at a controlled rate.
DETENTION BASIN
An impoundment designed to collect and retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. Detention basins are designed to drain completely shortly after any given rainfall event.
DETENTION VOLUME
The volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.
DEVELOPER
A person who seeks to undertake any regulated activities at a site in the Township
DIAMETER AT BREAST HEIGHT (DBH)
The outside bark diameter of a tree at breast height which is defined as 4.5 feet (1.37 m) above the forest floor on the uphill side of the tree.
DISTURBED AREA
Land area disturbed by or where an earth disturbance activity is occurring or has occurred.
DRAINAGE AREA
That land area contributing runoff to a single point (including but not limited to the point/line of interest used for hydrologic and hydraulic calculations) and that is enclosed by a natural or man-made ridge line.
EARTH DISTURBANCE (or 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; and the moving, depositing, stockpiling, or storing of soil, rock, or earth materials.
EASEMENT
A right of use granted by a landowner to allow a grantee the use of the designated portion of land for a specified purpose, such as for stormwater management or other drainage purposes.
EROSION
The process by which the surface of the land, including water/stream channels, is worn away by water, wind, or chemical action.
EROSION AND SEDIMENT CONTROL PLAN
A plan required by the Conservation District or the Township to minimize accelerated erosion and sedimentation, and that must be prepared and approved per the applicable requirements.
FEMA
Federal Emergency Management Agency.
FLOOD
A temporary condition of partial or complete inundation of land areas from the overflow of streams, rivers, and other waters of this commonwealth.
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.
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 center line of the stream and to 50 feet beyond the top of the bank of the stream on both sides.
FOREST MANAGEMENT/TIMBER OPERATIONS
Planning and activities necessary for the management of forest lands. These include timber inventory, preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation, and reforestation.
FREEBOARD
A vertical distance between the design high-water elevation and the elevation of the top of a dam, levee, tank, basin, swale, or diversion berm. The space is required as a safety margin in a pond or basin.
GEOTEXTILE
A fabric manufactured from synthetic fiber that is used to achieve specific objectives, including infiltration, separation between different types of media (i.e., between soil and stone), or filtration.
GOVERNING BODY
The Board of Supervisors of West Nantmeal Township.
GRADE/GRADING
A. 
A slope, usually of a road, channel, or natural ground, specified in percent and shown on plans as specified herein.
B. 
To finish the surface of a roadbed, the top of an embankment, or the bottom of an excavation.
GROUNDWATER
Water that occurs in the subsurface and fills or saturates the porous openings, fractures and fissures of underground soils and rock units.
GROUNDWATER RECHARGE
The replenishment of existing natural groundwater supplies from infiltration of rain or overland flow.
HEC-1
The U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC) Hydrologic Runoff Model.
HEC-HMS
The U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC) - Hydrologic Modeling System (HMS).
HIGH TUNNEL
A structure which meets the following:
[Added 11-11-2019 by Ord. No. 4-2019]
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 Forest Land Assessment Act of 1974,"[1] or for the storage of agricultural equipment or supplies; and
B. 
Is constructed with all the following:
(1) 
Has a metal, wood or plastic frame;
(2) 
When covered, has a plastic, woven textile or other flexible covering; and
(3) 
Has a floor made of soil, crushed stone, matting, pavers or a floating concrete slab.
HOT SPOTS
Areas where prior or existing land use or activities can potentially generate highly contaminated runoff with concentrations of pollutants in excess of those typically found in stormwater.
HYDROLOGIC REGIME
The hydrologic system, cycle or balance that sustains the quality and quantity of stormwater, stream base flow, storage, and groundwater supplies under natural conditions.
HYDROLOGIC SOIL GROUP (HSG)
A classification of soils by the Natural Resources Conservation Service (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.
IMPERVIOUS SURFACE
A surface that has been compacted or covered with a layer of material so that it prevents or is resistant to infiltration of water, including but not limited to structures such as roofs, buildings, storage sheds; other solid, paved or concrete areas such as streets, driveways, sidewalks, parking lots, patios, decks, tennis or other paved courts; or athletic play fields comprised of synthetic turf materials. For the purposes of determining compliance with this chapter, compacted soils or stone surfaces used for vehicle parking and movement shall be considered impervious. Surfaces that were designed to allow infiltration (i.e., areas of porous pavement) will be considered on a case-by-case basis by the Municipal Engineer, based on appropriate documentation and condition of the material, etc.
INFILTRATION
Movement of surface water into the soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolated downward to recharge groundwater.
INFILTRATION FACILITY
A stormwater BMP designed to collect and discharge runoff into the subsurface in a manner that allows infiltration into underlying soils and groundwater (e.g., french drains, seepage pits, or seepage trenches, etc.).
INTERMITTENT STREAM
A defined channel in which surface water is absent during a portion of the year, in response to seasonal variations in precipitation or groundwater discharge.
INVERT
The lowest surface, the floor or bottom of a culvert, pipe, drain, sewer, channel, basin, BMP or orifice.
KARST
A type of topography that is formed over limestone or other carbonate rock formations by dissolving or solution of the rock by water, and that is characterized by closed depressions, sinkholes, caves, a subsurface network of solution conduits and fissures through which groundwater moves, and no perennial surface drainage features.
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. 
A subdivision of land;
C. 
Development in accordance with Section 503(1.1) of the Pennsylvania Municipalities Planning Code (as amended).[2]
LANDOWNER
The legal or beneficial owner or owners of land, including the holder of an option or contract to purchase (whether or not such option or contract is subject to any condition), a lessee if they are authorized under the lease to exercise the rights of the landowner, or other person having a proprietary interest in the land.
LICENSED PROFESSIONAL
A Pennsylvania registered professional engineer, registered landscape architect, registered professional land surveyor, or registered professional geologist, or any person licensed by the Pennsylvania Department of State and qualified by law to perform the work required by this chapter within the Commonwealth of Pennsylvania.
LIMITING ZONE
A soil horizon or condition in the soil profile or underlying strata that includes one of the following:
A. 
A seasonal high-water table, whether perched or regional, determined by direct observation of the water table or indicated by other subsurface or soil conditions.
B. 
A rock with open joints, fracture or solution channels, or masses of loose rock fragments, including gravel, with insufficient fine soil to fill the voids between the fragments.
C. 
A rock formation, other stratum, or soil condition that is so slowly permeable that it effectively limits downward passage of water.
MAINTENANCE
The action taken to restore or preserve the as-built functional design of any facility or system.
MFEMP
Mushroom Farm Environmental Management Plan.
MPC
Act of July 31, 1968, P.L. 805, No. 247, 53 P.S. § 10101 et seq., as amended, the Pennsylvania Municipalities Planning Code, Act 247.
MUNICIPAL ENGINEER
A professional engineer licensed as such in the Commonwealth of Pennsylvania, duly appointed as the engineer for a municipality/township, planning agency, or joint planning commission.
MUNICIPALITY
West Nantmeal, Chester County, Pennsylvania.
NEW DEVELOPMENT
Any regulated activity involving placement or construction of new impervious surface or grading over existing pervious land areas not classified as redevelopment as defined in this chapter.
NOAA
National Oceanic and Atmospheric Administration.
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.
NONSTORMWATER DISCHARGES
Water flowing in stormwater collection facilities, such as pipes or swales, which is not the result of a rainfall event or snowmelt.
NONSTRUCTURAL BEST MANAGEMENT PRACTICE (BMPs)
See "best management practice (BMP)."
NPDES
National Pollutant Discharge Elimination System, the federal government's system for issuance of permits under the Clean Water Act,[3] which is delegated to PADEP in Pennsylvania.
NRCS
Natural Resource Conservation Service (previously Soil Conservation Service, SCS), an agency of the U.S. Department of Agriculture.
PADEP
Pennsylvania Department of Environmental Protection.
PARENT TRACT
The parcel of land from which a land development or subdivision originates, determined from the date of municipal adoption of this chapter.
PEAK DISCHARGE
The maximum rate of stormwater runoff from a specific storm event.
PENNDOT
Pennsylvania Department of Transportation.
PENNSYLVANIA STORMWATER BEST MANAGEMENT PRACTICES MANUAL (PADEP BMP MANUAL)
Document Number 363-0300-002 (December 2006, and as subsequently amended).
PERVIOUS SURFACE (or PERVIOUS AREA)
Any area not defined as impervious surface.
PLANNING COMMISSION
The Planning Commission of West Nantmeal.
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 § 92a.2.
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
POST-CONSTRUCTION
Period after construction during which disturbed areas are stabilized, stormwater controls are in place and functioning, and all proposed improvements approved by the Township are completed.
PREDEVELOPMENT
Land cover conditions assumed to exist within the proposed disturbed area prior to commencement of the regulated activity for the purpose of calculating the predevelopment water quality volume, infiltration volume, and peak flow rates as required in this chapter.
PRETREATMENT
Techniques employed in stormwater BMPs to provide storage or filtering, or other methods to trap or remove coarse materials and other pollutants before they enter the stormwater system, but may not necessarily be designed to meet the entire water quality volume requirements of this chapter.
PROPOSED IMPERVIOUS SURFACE
All new, additional and replacement impervious surfaces.
RAINFALL INTENSITY
The depth of accumulated rainfall per unit of time.
RECHARGE
The replenishment of groundwater through the infiltration of rainfall, other surface waters, or land application of water or treated wastewater.
REDEVELOPMENT
Any regulated activity that involves demolition, removal, reconstruction, or replacement of existing impervious surface(s).
REGULATED ACTIVITY
Any earth disturbance activity(ies) or any activity that involves the alteration or development of land in a manner that may affect stormwater runoff.
REGULATED EARTH DISTURBANCE ACTIVITY
Any activity involving earth disturbance subject to regulation under 25 Pa. Code Chapter 92a, Chapter 102, or the Clean Streams Law.[4]
[Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I)]
RETENTION BASIN
An impoundment that is designed to temporarily detain a certain amount of stormwater from a catchment area and which may be designed to permanently retain stormwater runoff from the catchment area; retention basins always contain water.
RETENTION or TO RETAIN
The prevention of direct discharge of stormwater runoff into surface waters or water bodies during or after a storm event by permanent containment in a pond or depression; examples include systems which discharge by percolation to groundwater, exfiltration, and/or evaporation processes and which generally have residence times of less than three days.
RETENTION VOLUME/REMOVED RUNOFF
The volume of runoff that is captured and not released directly into the surface waters of the 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
Pertaining to anything connected with or immediately adjacent to the banks of a stream or other body of water.
RIPARIAN BUFFER
An area of land adjacent to a body of water and managed to maintain vegetation to protect the integrity of stream channels and shorelines, to reduce the impact of upland sources of pollution by trapping, filtering and converting sediments, nutrients, and other chemicals, and to supply food, cover and thermal protection to fish and other aquatic species and wildlife.
RUNOFF
Any part of precipitation that flows over the land surface.
SALDO
See "subdivision and land development ordinance."
SCS
Soil Conservation Service, now known as the "Natural Resources Conservation Service."
SEDIMENT
Soil or other materials transported by, suspended in or deposited by surface water as a product of erosion.
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
A flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.
SITE
Total area of land in the Township where any proposed regulated activity, as defined in this chapter, is planned, conducted, or maintained or that is otherwise impacted by the regulated activity.
SOIL COVER COMPLEX METHOD
A method of runoff computation developed by NRCS that is based on relating soil type and land use/cover to a runoff parameter called "curve number (CN)".
STATE WATER QUALITY REQUIREMENTS
The regulatory requirements to protect, maintain, reclaim, and restore water quality under Pennsylvania Code Title 25 and the Clean Streams Law.[5]
STORM FREQUENCY
See "return period."
STORMWATER
Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
STORMWATER MANAGEMENT (SWM) SITE PLAN
The plan prepared by the applicant or its representative, in accordance with the requirements of Article IV of this chapter, indicating how stormwater runoff will be managed at a particular site in accordance with this chapter, and including all necessary design drawings, calculations, supporting text, and documentation to demonstrate that the requirements of this chapter have been met, herein referred to as "SWM site plan." All references in this chapter to "final" or "approved" SWM site plans shall incorporate the approved SWM site plan and all subsequent approved revisions thereto.
STORMWATER MANAGEMENT FACILITY
Any feature, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff quality, rate, or quantity. Typical stormwater management facilities include, but are not limited to, detention and retention basins, open channels, storm sewers, pipes, and infiltration facilities.
STREAM
A natural watercourse.
STRUCTURAL STORMWATER MANAGEMENT PRACTICES
See "BMP (best management practices)."
SUBDIVISION
The division or redivision of a lot, tract, or parcel of land as defined in The Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, No. 247 (as amended).[6]
SUBDIVISION AND LAND DEVELOPMENT ORDINANCE
The Subdivision and Land Development Ordinance of West Nantmeal, Chester County, PA, as amended; Chapter 170, Subdivision and Land Development, of this Code.
SWALE
An artificial or natural waterway or low-lying stretch of land that gathers and conveys stormwater or runoff and is generally vegetated for soil stabilization, stormwater pollutant removal, and infiltration.
SWM SITE PLAN
See "stormwater management site plan."
TIMBER OPERATIONS
See "forest management."
TOP-OF-BANK
Highest point of elevation of the bank of a stream or channel cross section at which a rising water level just begins to flow out of the channel and into the floodplain.
TOWNSHIP
West Nantmeal, Chester County, Pennsylvania.
TOWNSHIP ENGINEER
A professional engineer licensed as such in the Commonwealth of Pennsylvania, duly appointed as the engineer for a Township.
USDA
United States Department of Agriculture.
WATER TABLE
The uppermost level of saturation of pore space or fractures by groundwater. Seasonal high-water table refers to a water table that rises and falls with the seasons due either to natural or man-made causes.
WATERCOURSE
A channel or conveyance of surface water having a 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 and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of the commonwealth.
WATERSHED
Region or area drained by a river, watercourse, or other body of water, whether natural or artificial.
WETLAND
Those areas that are inundated or saturated by surface water 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. Wetlands generally include swamps, marshes, bogs, fens, and similar areas.
WOODS
Any land area of at least 0.25 acre with a natural or naturalized ground cover (excluding manicured turf grass) and that has an average density of two or more viable trees per 1,500 square feet with a DBH of six inches or greater and where such trees existed at any time within three years of the time of land development application submission of the proposed project. The land area to be considered "woods" shall be measured from the outer driplines of the outer trees.
[1]
Editor's Note: See 72 P.S. § 5490.1 et seq.
[2]
Editor's Note: See 53 P.S. § 10503(1.1).
[3]
Editor's Note: See 33 U.S.C. § 1251 et seq.
[4]
Editor's Note: See 35 P.S. § 691.1 et seq.
[5]
Editor's Note: See 35 P.S. § 691.1 et seq.
[6]
Editor's Note: See 53 P.S. § 10101 et seq.