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.
(d) The words “used or occupied” include the words “intended, designed, maintained, or arranged to be used or occupied.”
(e) Specific definitions:
(1) “Accelerated erosion.” The removal of the surface of the land through the combined action of man's activity and the natural processes of a rate greater than would occur because of the natural process alone.
(2) “Agricultural Activity.” 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”.
(3) “Alteration.” As applied to land, a change in topography because of the moving of soil and rock from one location or position to another; also the changing of surface conditions by causing the surface to be more or less impervious; land disturbance.
(4) “Applicant.” A landowner, developer or other person who has filed an application for approval to engage in any regulated earth-disturbance activity at a project site in the Municipality.
(5) “Bank full.” The channel at the top-of-bank or point where water begins to overflow onto a floodplain.
(6) “Base flow.” Portion of stream discharge derived from ground water; the sustained discharge that does not result from direct runoff or from water diversions, reservoir releases, piped discharges, or other human activities.
(7) “Bioretention.” A storm water retention area that utilizes woody and herbaceous plants and soils to remove pollutants before infiltration occurs.
(8) “BMP (Best Management Practice).” Activities, facilities, designs, measures or procedures used to manage storm water impacts from regulated activities, to meet State water quality requirements, to promote ground water 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. Structural SWM BMPs are permanent appurtenances to the project site.
(9) “Carbonate bedrock (areas).” 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.
(10) “Channel.” A drainage element in which storm water flows with an open surface. Open channels include, but shall not be limited to, natural and man-made drainage ways, swales, streams, ditches, canals, and pipes flowing partly full.
(11) “Channel erosion.” The widening, deepening, and headward cutting of small channels and waterways, caused by storm water runoff or bank full flows.
(12) “Cistern.” An underground reservoir or tank for storing rain water.
(13) “Conservation District.” A conservation district, as defined in section 3(c) of the Conservation District Law (3 P.S. § 851(c)), which has the authority under a delegation agreement executed with the Department to administer and enforce all or a portion of the erosion and sediment control program in this Commonwealth.
(14) “Culvert.” A structure with appurtenant works, which carries water under or through an embankment or fill.
(15) “Dam.” An artificial barrier, together with its appurtenant works, constructed for the purpose of impounding or storing water or another fluid or semi-fluid, or a refuse bank, fill or structure for highway, railroad or other purposes which does or may impound water or another fluid or semi- fluid.
(16) “Delineation.” The process of determining a wetland's physical boundaries.
(17) “Design storm.” The magnitude and temporal distribution of precipitation from a storm event measured in probability of occurrence (e.g. a 5-year storm) and duration (e.g. 24 hours), used in the design and evaluation of Storm water management systems. (See Return period)
(18) “Designee.” The agent of the Lawrence County Planning Commission, Lawrence County Conservation District and/or agent of the governing body involved with the administration, review or enforcement of any provisions of this chapter by contract or memorandum of understanding.
(19) “Detention.” The volume of runoff that is captured and released into the waters of this Commonwealth at a controlled rate.
(20) “Detention basin.” An impoundment designed to collect and attenuate storm water peak 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 and are dry until the next rainfall event.
(21) “Development.” See “Earth-disturbance activity.” The term includes redevelopment.
(22) “Discharge.” To release water from a project, site, aquifer, drainage basin or other point of interest (verb); the rate and volume of flow of water such as in a stream, generally expressed in cubic feet per second (volume per unit of time) (noun). See also Peak Discharge.
(23) “Discharge point.” The point to which storm water flows.
(24) “Disconnected impervious area (DIA).” An impervious or impermeable surface that is disconnected from any storm water drainage or conveyance system and is redirected or directed to a pervious area, which allows for infiltration, filtration, and increased time of concentration as specified in the Appendices attached to Ordinance 2458.
(25) “Disturbed area.” An unstabilized land area where an earth-disturbance activity is occurring or has occurred.
(26) “Ditch.” (See Channel).
(27) “Down slope property line.” That portion of the property line of the lot, tract, or parcels of land being developed located such that overland or pipe flow from the site would flow towards it.
(28) “Drainage easement.” A right granted by a landowner to a grantee, allowing the use of private land for storm water management purposes.
(29) “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.
(30) “Emergency spillway.” A conveyance area that is used to pass peak discharge greater than the maximum design storm controlled by a storm water management facility.
(31) “Encroachment.” A structure or activity that changes, expands, or diminishes the course, current or cross-section of a watercourse, floodway, floodplain, or body of water.
(32) “Ephemeral stream.” A stream with flowing water only during, and for a short duration after, precipitation events in a typical year. Ephemeral stream beds are located above the water table year-round. Ground water is not a source of water for the stream. Runoff from rainfall is the primary source of water for stream flow.
(33) “Erosion.” The natural process by which the surface of the land is worn away by water, wind or chemical action.
(34) “Erosion and Sediment Pollution Control Plan.” A plan for a project site which identifies BMPs to minimize accelerated erosion and sedimentation.
(35) “Exceptional value waters.” Surface waters of high quality which satisfy Pennsylvania Code Title 25 Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(b) (relating to anti-degradation).
(36) “Extended detention volume (EDV).” Release of detained runoff in excess of permanently removed volume (PRV) over a period of time not less than 24 and not more than 72 hours.
(37) “Existing condition.” The dominant land cover during the five-year period immediately preceding a proposed regulated activity.
(38) “Felling.” The process of cutting down standing trees.
(39) “Flood.” A temporary condition of partial or complete inundation of land areas from the overflow of streams, rivers, and other waters of this Commonwealth.
(40) “Floodplain.” Any land area susceptible to inundation by water from any natural source or delineated by applicable Federal Emergency Management Agency (FEMA) maps and studies as being a special flood hazard area. Also included are areas that comprise Group 13 Soils, as listed in Appendix A of the Pennsylvania Department of Environmental Protection (PA DEP) Technical Manual for Sewage Enforcement Officers (as amended or replaced from time to time by PA DEP).
(41) “Floodway.” The channel of the watercourse and those portions of the adjoining floodplain that is 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, the floodway includes floodplain areas within 50 feet of the top of each stream bank and the stream channel itself.
(42) “Forest management/timber operations.” Planning and activities necessary for the management of forest land. These include timber inventory and preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation and reforestation.
(43) “Freeboard.” A vertical distance between the elevation of the design high water elevation and 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.
(44) “Grade.” A slope, usually of a road, channel or natural ground specified in percent and shown on plans as specified herein. “(To) Grade” means to finish the surface of a roadbed, top of embankment or bottom of excavation.
(45) “Grassed waterway.” A natural or constructed waterway, usually broad and shallow, covered with erosion-resistant grasses, used to convey surface water.
(46) “Ground water.” Water beneath the earth's surface, often between saturated soil and rock that supplies wells and springs.
(47) “Ground water recharge.” Replenishment of existing natural underground water supplies without degrading ground water quality.
(48) “Harvesting.” The felling, skidding, loading, and transporting of timber products.
(49) “High quality waters.” Surface waters having quality which exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water by satisfying Pennsylvania Code Title 25 Environmental Protection, Chapter 93 Water Quality Standards, § 93.4b(a).
(50) “Hydric soils.” Soils that are characterized by the presence of water.
(51) “Hydrograph.” A graph of storm water or runoff discharge versus time for a selected point in the drainage system.
(52) “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 Natural Resources Conservation Service (NRCS) of the U.S. 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 underlying the project 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.
(53) “Hydrophytic vegetation.” Plant life that is adapted to living in wet conditions.
(54) “Impervious surface (impervious area).” A surface that prevents the infiltration of water into the ground. “Impervious surfaces” (or covers) shall include, but not be limited to:
A. Roofs, additional indoor living spaces, patios, garages, storage sheds and similar structures;
B. New streets or sidewalks, decks, parking areas, and driveway areas using traditional paved surfaces that prevent infiltration into the ground. New decks, parking areas, and driveways are not defined as impervious areas if they are designed to allow long-term infiltration;
C. Existing gravel parking areas, driveways, and roads shall be treated as slightly pervious and shall be analyzed using the appropriate SCS curve number based on their HSG; proposed gravel parking areas, driveways, and roads shall be treated as impervious areas for all calculations.
(55) “Impoundment.” A retention or detention basin designed to retain storm water runoff and release it at a controlled rate.
(56) “Infiltration.” Movement of surface water into the soil, where it is absorbed by plant roots, evaporates into the atmosphere, or percolates downward to recharge ground water.
(57) “Infiltration structures.” A structure designed to direct runoff into the ground water (e.g., French drains, seepage pits, and seepage trench).
(58) “Inlet.” The upstream end of any structure through which water may flow.
(59) “Intermittent stream.” A stream with flowing water during certain times of the year, when ground water provides water for stream flow. During dry periods, intermittent streams may not have flowing water. Runoff from rainfall is a supplemental source of water for stream flow.
(60) “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.
(61) “Land development (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.
(62) “Landing (or deck).” A place where logs or tree-length materials are assembled for loading and transport.
(63) “Litter layer.” The layer of fallen leaves, twigs, and decaying woody material that provides a sponge-like mat covering forest soils.
(64) “Lot.” A part of a subdivision or a parcel of land used as a building site or intended to be used for building purposes, whether immediate or future, which would not be further subdivided.
(65) “Main stem (main channel).” Any stream segment or other runoff conveyance facility used as a reach in the hydrologic model.
(66) “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.
(67) “Municipal Engineer.” A professional engineer licensed as such in the Commonwealth of Pennsylvania, duly appointed as the engineer for a Municipality, planning agency or joint planning commission.
(68) “Municipality.” Borough of Ellwood City, Lawrence/Beaver County, Pennsylvania.
(69) “Natural recharge area.” Undisturbed surface area or depression where storm water collects, and a portion of which infiltrates and replenishes the underground and ground water.
(70) “Non-point source pollution.” Pollution that enters a water body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
(71) “Non-structural Best Management Practice (BMPs).” Methods of controlling storm water runoff quantity and quality, such as innovative site planning, impervious area and grading reduction, protection of natural depression areas, temporary ponding on-site and other techniques.
(72) “NPDES.” National Pollutant Discharge Elimination System, the Federal government's system for issuance of permits under the Clean Water Act, which is delegated to PA DEP in Pennsylvania.
(73) “NRCS.” Natural Resources Conservation Service (previously SCS).
(74) “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.
(75) “Outlet.” Points of water disposal to a stream, river, lake, tidewater or artificial drain.
(76) “PA DEP.” The Pennsylvania Department of Environmental Protection.
(77) “PA DOT.” Pennsylvania Department of Transportation.
(78) “Parent tract.” The parcel of land from which a land development or subdivision originates, determined from the date of Municipal adoption of this chapter.
(79) “Parking lot storage.” The use of parking areas as temporary impoundments with controlled release rates during rainstorms.
(80) “Peak discharge.” The maximum rate of storm water runoff from a specific storm event.
(81) “Permanently removed volume (PRV).” The volume of runoff that is permanently removed from the runoff and not released into surface waters of this Commonwealth during or after a storm event.
(82) “Pervious surface (pervious area).” Any area or ground surface not defined as impervious and that may be vegetated or un-vegetated.
(83) “Pipe.” A culvert, closed conduit, or similar structure (including appurtenances) that conveys storm water.
(84) “Planning Commission.” The Municipal or County Planning Commission authorized under the Pennsylvania Municipalities Planning Code.
(85) “Point source.” Any discernible, confined and discrete conveyance, including, but not limited to, any pipe, ditch, channel, tunnel, or conduit from which storm water is or may be discharged, as defined in State regulations at 25 Pa. Code § 92.1.
(86) “Post-construction.” Period after construction where disturbed areas are stabilized, storm water controls are in place and functioning and all proposed improvements in the approved land development plan are completed.
(87) “Pre-development.” Undeveloped/natural condition.
(88) “Pre-treatment.” Techniques employed in storm water BMPs to provide storage or filtering to trap coarse materials and other pollutants before they enter the system.
(89) “Project site.” The specific area of land where any regulated activities in the Municipality are planned, conducted, or maintained.
(90) “Qualified professional.” A professional engineer licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the engineering work required by this chapter.
(91) “Recharge.” The replenishment of ground water through the infiltration of rainfall or storm water runoff.
(92) “Record drawings.” Those drawings maintained by the applicant, applicant's contractor, or applicant's agent as the applicant’s project is constructed; and upon which is documented the actual locations of the building components and changes to the original contract documents. These, or a copy of same, are turned over to the Municipality at the completion of the project.
(93) “Redevelopment.” The demolition, construction, reconstruction, alteration, or improvement exceeding 2,000 square feet of land disturbance performed on sites where existing land use is commercial, industrial, institutional, or multifamily residential. Maintenance activities such as top-layer grinding and re-paving are not considered redevelopment. Interior remodeling projects and tenant improvements are also not considered redevelopment. Utility trenches in streets are not considered redevelopment unless more than 50% of the street width is removed and re-paved.
(94) “Regulated activities.” All activities involving land development or earth disturbance activity that may affect storm water runoff.
(95) “Regulated earth-disturbance activity.” Activity involving earth disturbance subject to regulation under 25 PA Code Chapters 92, Chapter 102, or the Clean Streams Law.
(96) “Release rate.” The percentage of existing conditions peak rate of runoff from a site or subarea to which the post-development peak rate of runoff must be reduced to protect downstream areas.
(97) “Retention basin.” A structure in which storm water is stored and not released during the storm event. “Retention basins” do not function without operational intervention to release stored storm water unless designed as infiltration-only basins.
(98) “Retention/removed.” The volume of runoff that is captured and not released directly into the surface waters of this Commonwealth during or after a storm event.
(99) “Return period.” The interval, in years, within which a storm event of a given magnitude can be expected, on average, to recur. For example, the 25-year return period rainfall would be expected, on average, to recur every 25 years. The probability of a 25-year storm occurring in any one year is 0.04 or 4%.
(100) “Riser.” A vertical pipe extending from the bottom of a pond that is used to control the discharge rate from the pond for a specified design storm.
(101) “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.
(102) “Roof drains.” A drainage conduit or pipe that collects water runoff from a roof and leads it away from the structure.
(103) “Rooftop detention.” Temporary ponding and gradual release of storm water falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs.
(104) “Runoff.” Any part of precipitation that flows over the land.
(105) “SALDO.” Subdivision and Land Development Ordinance.
(106) “SCS.” Soil Conservation Service (currently known as NRCS, Natural Resources Conservation Service). Also a commonly referred to method (“SCS Method”) for the hydrologic computation and estimation of runoff from rainfall information that has been developed by the United States Department of Agriculture's Soil Conservation Service (SCS).
(107) “Sediment.” Soils or other materials transported by surface water as a product of erosion.
(108) “Sediment basin.” A barrier, dam, retention or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by water during construction.
(109) “Sediment pollution.” The placement, discharge or any other introduction of sediment into the waters of the Commonwealth.
(110) “Sedimentation.” The process by which mineral or organic matter is accumulated or deposited by the movement of water or air.
(111) “Seepage pit/seepage trench.” An area of excavated earth filled with loose stone or similar coarse material, into which surface water is directed for infiltration into the ground water.
(112) “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 storm water runoff.
(113) “Shallow concentrated flow.” Storm water runoff flowing in shallow, defined rills prior to entering a defined channel or waterway.
(114) “Sheet flow.” A flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.
(115) “Skid road/haul road.” Those roads, trails, or other openings upon which trees, logs, equipment, or vehicles are moved within the site of the work.
(116) “Skidding.” Moving of logs or felled trees along the surface of the ground from the stump to the point of loading.
(117) “Slash.” Unusable woody material such as large limbs, tops, cull logs, and stumps that remain after timber harvesting.
(118) “Soil-cover complex method.” A method of runoff computation developed by the NRCS that is based on relating soil type and land use/cover to a runoff parameter called Curve Number (CN).
(119) “Special geologic features.” Carbonate bedrock features, including but not limited to closed depressions, existing sinkholes, fracture traces, lineaments, joints, faults, caves and pinnacles, which may exist and must be identified on a site when storm water management BMPs are being considered.
(120) “Spillway.” A conveyance that is used to pass the peak discharge of the maximum design storm controlled by the storm water facility.
(121) “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.
(122) “Storage indication method.” A reservoir routing procedure based on solution of the continuity equation (inflow minus outflow equals the change in storage) with outflow defined as a function of storage volume and depth.
(123) “Storm frequency.” The number of times that a given storm event occurs or is exceeded on the average in a stated period of years. See “Return Period”.
(124) “Storm sewer.” A system of pipes and/or open channels that convey intercepted runoff and storm water from other sources, but exclude domestic sewage and industrial wastes.
(125) “Storm water.” Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
(126) “Storm water management BMPs.” Abbreviated as SWM BMPs throughout this chapter.
(127) “Storm water management facility.” Any structure, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects storm water runoff. Typical “storm water management facilities” include, but are not limited to, detention and retention basins, open channels, storm sewers, pipes, and infiltration structures.
(128) “Storm Water Management Plan.” The plan for managing storm water runoff adopted by the County of Lawrence as required by the Act of October 4, 1978, P.L. 864, (Act 167), as amended, and known as the “Storm Water Management Act”.
(129) “Storm Water Management Site Plan.” The plan prepared by the applicant or his representative indicating how storm water runoff will be managed at the project site in accordance with this chapter. “Storm Water Management Site Plan” will be designated as SWM Site Plan throughout this chapter.
(130) “Stream.” A natural watercourse.
(131) “Stream enclosure.” A bridge, culvert or other structure in excess of 100 feet in length upstream to downstream that encloses a regulated water of this Commonwealth.
(132) “Subarea (sub-watershed).” The smallest drainage unit of a watershed for which storm water management criteria have been established in the Storm Water Management Plan.
(133) “Subdivision.” The division or re-division 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 (Refer to the PA Municipalities Planning Code, current version).
(134) “Surface waters of the/this Commonwealth.” Any and all rivers, streams, creeks, rivulets, ditches, watercourses, storm sewers, lakes, dammed water, wetlands, ponds, springs, and all other bodies or channels of conveyance of surface, or parts thereof, whether natural or artificial, within or on the boundaries of this Commonwealth.
(135) “Swale.” A low-lying stretch of land that gathers or carries surface water runoff.
(136) “Timber operations.” See Forest Management.
(137) “Time-of-concentration (Tc).” The time for surface runoff to travel from the hydraulically most distant point of the watershed to a point of interest within the watershed. This time is the combined total of overland flow time and flow time in pipes or channels, if any.
(138) “Top-of-bank.” Highest point of elevation in a stream channel cross-section at which a rising water level just begins to flow out of the channel and over the floodplain.
(139) “USACE.” United States Army Corp of Engineers.
(140) “Vernal pond.” Seasonal depressional wetlands that are covered by shallow water for variable periods from winter to spring, but may be completely dry for most of the summer and fall.
(141) “Watercourse.” A channel or conveyance of surface water having defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
(142) “Waters of the/this Commonwealth.” Rivers, streams, creeks, rivulets, impoundments, ditches, watercourses, storm sewers, lakes, dammed water, wetlands, ponds, springs and 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.
(143) “Watershed.” Region or area drained by a river, watercourse or other body of water, whether natural or artificial.
(144) “Wet basin.” A detention basin that is designed to detain storm water and which always contains water.
(145) “Wetland.” Those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, fens, and similar areas.
(Ord. 2458. Passed 11-15-10.)