A.
For the purpose of this chapter, certain terms and words used herein shall be interpreted as follows:
(1)
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.
(2)
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.
(3)
The word "person" includes an individual, firm, association, organization, partnership, trust, company, corporation, or any other similar entity.
(4)
The words "shall" and "must" are mandatory; the words "may" and "should" are permissive.
(5)
The words "used or occupied" include the words "intended, designed, maintained, or arranged to be used, occupied or maintained."
B. ACCELERATED EROSION AGRICULTURAL ACTIVITIES ALTERATION APPLICANT BEST MANAGEMENT PRACTICES (BMPs) BMP MANUAL CHANNEL EROSION CISTERN CONSERVATION DISTRICT CULVERT DAM DESIGNEE DESIGN STORM DETENTION BASIN DETENTION VOLUME DEVELOPER DEVELOPMENT SITE (SITE) DISTURBED AREA DOWNSLOPE PROPERTY LINE DRAINAGE CONVEYANCE FACILITY DRAINAGE EASEMENT DRAINAGEWAY EARTH DISTURBANCE ACTIVITY EROSION EROSION AND SEDIMENT POLLUTION CONTROL PLAN EXCEPTIONAL VALUE WATERS EXISTING CONDITIONS FEMA FLOODPLAIN FLOODWAY FOREST MANAGEMENT/TIMBER OPERATIONS FREEBOARD GRADE (TO) GRADE GROUNDWATER RECHARGE HEC-HMS MODEL CALIBRATED HIGH QUALITY WATERS HYDROLOGIC SOIL GROUP (HSG) IMPERVIOUS COVER (a.k.a. IMPERVIOUS SURFACE AND IMPERVIOUS AREA) INFILTRATE INFILTRATION BMP INFILTRATION STRUCTURE INLET KARST LAND DEVELOPMENT or DEVELOPMENT(1) (a) [1] [2] [3] (b) (2) (a) (b) (c) LIMIT OF DISTURBANCE MAIN STEM (MAIN CHANNEL) MANNING EQUATION (MANNING FORMULA) NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) NOAA ATLAS 14 NONPOINT SOURCE POLLUTION NRCS OPEN CHANNEL OUTFALL OUTLET PADEP PARKING LOT STORAGE PEAK DISCHARGE PERSON PERVIOUS AREA PIPE PLANNING COMMISSION POINT SOURCE PROBABLE MAXIMUM FLOOD (PMF) PROJECT SITE QUALIFIED PROFESSIONAL RATIONAL FORMULA REDEVELOPMENT REGULATED ACTIVITIES REGULATED EARTH DISTURBANCE ACTIVITY RELEASE RATE RELEASE RATE DISTRICT RETENTION VOLUME/REMOVED RUNOFF RETURN PERIOD RIPARIAN BUFFER RISER ROAD MAINTENANCE ROOFTOP DETENTION RUNOFF RUNOFF CAPTURE VOLUME SEDIMENT SEDIMENTATION SEDIMENT BASIN SEDIMENT POLLUTION SEEPAGE PIT/SEEPAGE TRENCH SENSITIVE ENVIRONMENTAL AREAS(1) (2) (3) (4) (5) SEPARATE STORM SEWER SYSTEM SHEET FLOW SOIL COVER COMPLEX METHOD SPILLWAY (EMERGENCY) STATE WATER QUALITY REQUIREMENTS(1) (2) (3) (4) STORAGE INDICATION METHOD STORM FREQUENCY STORM SEWER STORMWATER STORMWATER HOTSPOT STORMWATER MANAGEMENT FACILITIES STORMWATER MANAGEMENT PLAN STORMWATER MANAGEMENT SITE PLAN (SWM SITE PLAN) STREAM ENCLOSURE SUBDIVISION SUBWATERSHED AREA SUPERVISORS SWALE TIMBER OPERATIONS TIME OF CONCENTRATION (Tc) TOWNSHIP USDA WATERCOURSE WATERSHED WATERS OF THE COMMONWEALTH WETLANDS
As used in this chapter, the following terms shall have the meanings indicated:
The removal of the surface of the land through the combined action of human activity and natural processes at a rate greater than would occur because of the natural process alone.
Activities associated with agriculture such as agricultural cultivation, agricultural operation, and animal-heavy use areas. This includes the work of producing crops, tillage, land clearing, plowing, disking, harrowing, planting, harvesting crops, or pasturing and raising of livestock and installation of conservation measures. The construction of new buildings or impervious areas, filling and excavating, road maintenance, maintenance and/or construction of fixed structures involving earth disturbance activity, and the moving, depositing, stockpiling, or storing of soil, rock or earth materials shall not be included in the definition of "agricultural activity."
As applied to land, a change in topography as a result of the moving of soil and rock from one location or position to another; changing of surface conditions by causing the surface to be more or less impervious; land disturbance.
A landowner, developer, or other person who has filed an application for approval to engage in any regulated activities at a project site within the Township of Derry.
Activities, facilities, designs, measures or procedures used to manage stormwater impacts from regulated activities, to meet state water quality requirements, to promote groundwater recharge, and to otherwise meet the purposes of this chapter. Stormwater BMPs are commonly grouped into one of two broad categories or measures: "nonstructural" or "structural". "Nonstructural" BMPs are measures referred to as operational and/or behavior-related practices that attempt to minimize the contact of pollutants with stormwater runoff whereas "structural" BMPs are measures 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 wet 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.
The Pennsylvania Stormwater Best Management Practices Manual as published by the Department of Environmental Protection, Bureau of Watershed Management, Document No. 363-0300-002, effective date: December 30, 2006, and as revised.
The widening, deepening, and headward cutting of small channels and waterways, due to erosion caused by moderate to large floods.
An underground reservoir or tank used for storing rainwater.
The Dauphin County Conservation District (DCCD). The Dauphin County Conservation District has the authority under a delegation agreement executed with the Department of Environmental Protection to administer and enforce all or a portion of the regulations promulgated under 25 Pa. Code Chapter 102.
A structure with appurtenant works that carries a stream and/or stormwater runoff under or through an embankment or fill.
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.
The agent of the Township of Derry 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.
The magnitude and temporal distribution of precipitation from a storm event measured in probability of occurrence (e.g., a twenty-five-year storm) and duration (e.g., 24 hours), used in the design and evaluation of stormwater management systems. Also see "return period."
An impoundment structure designed to manage stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate.
The volume of runoff that is captured and released during or after a storm event into waters of the commonwealth at a controlled rate.
A person, partnership, association, corporation, or other entity, or any responsible person therein or agent thereof, that undertakes any regulated activity of this chapter.
The specific tract of land for which a regulated activity is proposed. Also see "project site."
An unstabilized land area where an earth disturbance activity is occurring or has occurred.
That portion of the property line of the lot, tract, or parcels of land being developed located such that all overland or piped flow from the site would be directed toward it.
A stormwater management facility designed to convey stormwater runoff and shall include streams, channels, swales, pipes, conduits, culverts, storm sewers, etc.
A right granted by a landowner to a grantee, allowing the use of private land for stormwater management, drainage, or conveyance purposes.
Any natural or artificial watercourse, trench, ditch, pipe, swale, channel, or similar depression into which surface water flows.
A construction or other human activity which disturbs the surface of the land, including, but not limited to, clearing and grubbing, grading, excavations, embankments, land development, agricultural plowing or tilling, timber harvesting activities, road maintenance activities, mineral extraction, and the moving, depositing, stockpiling, or storing of soil, rock, or earth materials.
The movement of soil particles by the action of water, wind, ice, or other natural forces.
A plan which is designed to minimize accelerated erosion and sedimentation.
Surface waters of high quality, which satisfies Pa. Code Title 25, Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(b) (relating to antidegradation).
The initial condition of a project site prior to the proposed construction. If the initial condition of the site is not forested or undeveloped land, the land use shall be considered as "meadow" unless the natural land cover is documented to generate lower curve numbers or rational "C" coefficients, such as forested lands.
The Federal Emergency Management Agency.
For the purposes of this chapter, any land area susceptible to inundation by water from any natural source or delineated by applicable Department of Housing and Urban Development, Federal Insurance Administration Flood Hazard Boundary, mapped as being a special flood hazard area. Included are lands adjoining a river or stream that have been or may be inundated by a one-hundred-year flood. Also included are areas that comprise Group 13 Soils, as listed in Appendix A of the Pennsylvania Department of Environmental Protection (PADEP) Technical Manual for Sewage Enforcement Officers (as amended or replaced from time to time by PADEP).
The channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot.
Planning and activities necessary for the management of forestland. 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.
A vertical distance between the elevation of the design high water and the top of a dam, levee, tank, basin, or diversion ridge. The space is required as a safety margin in a pond or basin.
A slope, usually of a road, channel, or ground surface specified in percent and shown on plans as specified herein.
To finish the surface of a roadbed, top of embankment, or bottom of excavation.
Replenishment of existing natural underground water supplies.
(Hydrologic Engineering Center-Hydrologic Modeling System) A computer-based hydrologic modeling technique adapted to the watersheds in Dauphin County for the Act 167 Plan. The model has been calibrated by adjusting key model input parameters.
Surface water having quality, which exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water by satisfying Pa. Code Title 25, Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(a).
Infiltration rates of soils vary widely and are affected by subsurface permeability as well as surface intake rates. Soils are classified into one of four HSGs (A, B, C, and D) according to their minimum infiltration rate, which is obtained for bare soil after prolonged wetting. The Natural Resource 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 in the area of interest may be identified from a soil survey report from the local NRCS office or the DCCD.
A surface of a lot that has been compacted or covered with material to the extent that it is highly resistant to infiltration by water. Impervious cover (surfaces or areas) shall include, but is not limited to: conventional impervious surfaces such as paved streets, roofs, compacted stone, and sidewalks. Impervious cover shall consist of the following surfaces when used by motor vehicles or pedestrians: graveled areas, paver blocks (including voids), bricks, and cobblestone. The water area of swimming pools shall not be considered to be impervious surfaces if the overflow system of the pool is connected to a sanitary sewer system. Decks are not counted as impervious areas if they do not prevent infiltration. Any surface areas consisting of gravel, crushed stone, or other porous material shall be assumed to be impervious, unless designed and approved as an infiltration BMP.
To permeate water into the ground.
Any best management practice stormwater facility designed, approved, and maintained or used to direct runoff into the ground.
A structure designed to direct runoff into the ground (e.g., French drains, seepage pits, seepage trench, etc.).
A surface connection to a closed drain; a structure at the diversion end of a conduit; and/or the upstream end of any structure through which water may flow.
A type of topography or landscape characterized by surface depressions, sinkholes, rock pinnacles/uneven bedrock surface, steep-sided hills, underground drainage, and caves. Karst is formed on carbonate rocks, such as limestone or dolomites and sometimes gypsum.
Any of the following activities:
The improvement of one lot or two or more contiguous lots, tracts, or parcels of land for any purpose involving:
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.
The addition of 2,500 square feet of floor area to a nonresidential building or residential building, except single-family detached, two-family detached, single-family semidetached, and single-family attached dwellings.
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, buildings, groups, or other features.
A subdivision of land.
Exceptions. The following shall not be construed as land development activities:
The conversion of an existing single-family detached dwelling or single-family semidetached dwelling into not more than three residential units, unless such units are intended to be a condominium.
The addition of an accessory building, including farm buildings, on a lot of an existing principal building.
The conversion of buildings or rides within the confines of an enterprise which would be considered an amusement park. For the purposes of this subsection, an amusement park is defined as a tract or area used principally as a location for permanent amusement structures or rides. This exclusion shall not apply to newly acquired acreage by an amusement park until initial plans for the expanded area have been approved by the Township.
A line provided on the SWM site plan that indicates the total area to be disturbed during a proposed earth disturbance activity.
Any stream segment or other runoff conveyance facility used as a reach in the Dauphin County Act 167 watershed hydrologic model(s).
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.
The federal government's system for issuance of permits under the Clean Water Act, which is delegated to PADEP in Pennsylvania.
Precipitation-Frequency Atlas of the United States, Atlas 14, Volume 2, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service, Hydrometeorological Design Studies Center, Silver Spring, Maryland (2004) or latest edition. NOAA's Atlas 14 can be accessed at Internet address: http://hdsc.nws.noaa.gov/hdsc/pfds/.
Pollution that enters a water body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
Natural Resource Conservation Service [previously Soil Conservation Service (SCS)].
A drainage element in which stormwater flows with an open surface. Open channels include, but shall not be limited to, natural and man-made drainageways, swales, streams, ditches, canals, and pipes not under pressure.
i) The point where water flows from a conduit, stream, or drain; ii) "point source" as described in 40 CFR § 122.2, the point where the Township's storm sewer system discharges to surface waters of the commonwealth.
Points of water disposal from a stream, river, lake, tidewater, or artificial drain.
The Pennsylvania Department of Environmental Protection.
The use of impervious parking areas as temporary impoundments with controlled release rates during rainstorms.
The maximum rate of stormwater runoff from a specific storm event.
An individual, partnership, public or private association or corporation; or a governmental unit, public utility, or any other legal entity whatsoever which is recognized by law as the subject of rights and duties.
Any area not defined as impervious.
A culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.
The Planning Commission of the Township of Derry.
Any discernible, confined, or 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 Pennsylvania Code § 92.1.[1]
The flood that may be expected from the most severe combination of critical meteorological and hydrologic conditions that are reasonably possible in any area. The PMF is derived from the probable maximum precipitation (PMP) as determined on the basis of data obtained from the National Oceanographic and Atmospheric Administration (NOAA).
The specific area of land where any regulated activities in the Township are planned, conducted, or maintained.
Any person licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the work required by this chapter.
A rainfall-runoff relation used to estimate peak flow.
Earth disturbance activities on land which has previously been developed.
Any earth disturbance activities or any activities that involve the alteration or development of land in a manner that may affect stormwater runoff.
The percentage of predevelopment peak rate of runoff from a site or subwatershed area to which the postdevelopment peak rate of runoff must be reduced to protect downstream areas.
Those subwatershed areas in which postdevelopment flows must be reduced to a certain percentage of predevelopment flows as required to meet the plan requirements and the goals of Act 167.
The volume of runoff that is captured and not released directly into the surface waters of the commonwealth during or after a storm event.
The average interval, in years, within which a storm event of a given magnitude can be expected to recur. For example, the probability of a twenty-five-year storm occurring in any one given year is 0.04 (i.e., a four-percent chance).
A vegetated area bordering perennial and intermittent streams and wetlands that serves as a protective filter to help protect streams and wetlands from the impacts of adjacent land uses.
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.
Earth disturbance activities within the existing road right-of-way, such as grading and repairing existing unpaved road surfaces, cutting road banks, cleaning or clearing drainage ditches, and other similar activities. Road maintenance activities that do not disturb the subbase of a paved road such as milling and pavement overlays are not considered earth disturbance activities.
Temporary ponding and gradual release of stormwater falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs.
Any part of precipitation that flows over the land surface.
The volume of runoff that is captured (retained) and not released into surface waters of the commonwealth during or after a storm event.
Soils or other materials transported by surface water as a product of erosion.
The process by which mineral or organic matter is accumulated or deposited by the movement of water.
A barrier, dam, or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by stormwater runoff.
The placement, discharge, or any other introduction of sediment into waters of the commonwealth occurring from the failure to properly design, construct, implement, or maintain control measures and control facilities in accordance with the requirements of this chapter.
An area of excavated earth filled with loose stone or similar coarse material into which surface water is directed for infiltration into the ground.
Sensitive environmental areas shall consist of the following:
Land areas having slopes in excess of 20% which are not the result of man-made changes to the natural terrain.
Wetlands.
Areas of quarries, streams, lakes, dams, or ponds and all areas within 50 feet of such features.
Cemeteries and all areas within 50 feet of a cemetery.
Landfills and areas within 50 feet of a landfill.
A conveyance or system of conveyances (including roads with drainage systems, Township streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains) primarily used for collecting and conveying stormwater runoff.
Runoff that flows over the ground surface as a thin, even layer, not concentrated in a channel.
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).
A depression in the embankment of a pond or basin, or other overflow structure, that is used to pass peak discharges greater than the maximum design storm controlled by the pond or basin.
The regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code and the Clean Streams Law[4] including, but not limited to:
Each stream segment in Pennsylvania has a "designated use," such as "cold-water fishery" or "potable water supply," which is listed in Chapter 93. These uses must be protected and maintained, under state regulations.
"Existing uses" are those attained as of November 1975, regardless of whether they have been designated in Chapter 93. 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.
Water quality involves the chemical, biological, and physical characteristics of surface water bodies. After 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.
Protection and maintenance of water quality in special protection streams pursuant to 25 Pa. Code, Chapter 93.
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.
The number of times that a given storm event occurs or is exceeded on the average in a stated period of years. See also "return period."
A system of pipes and/or open channels that convey intercepted runoff and stormwater from other sources, but excludes domestic sewage and industrial wastes.
Drainage runoff from the surface of the land resulting from precipitation; or snow or ice melt.
A land use or activity that generates higher concentrations of hydrocarbons, trace metals, or toxicants than are found in typical stormwater runoff.
Any structure, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff. Typical stormwater management facilities include, but are not limited to: detention basins, wet ponds, open channels, storm sewers, pipes, roof leaders, and infiltration facilities.
The Dauphin County Stormwater Management Plan for managing stormwater runoff in Dauphin County as required by the Act of October 4, 1978, P.L. 864, (Act 167) and known as the "Stormwater Management Act."[5]
The plan prepared by the applicant or his representative indicating how stormwater runoff will be managed at the project site in accordance with this chapter.
A bridge, culvert, or other structure in excess of 100 feet in length upstream to downstream which encloses regulated waters of the commonwealth.
The division or redivision of a lot, tract, or parcel of land by any means into two or more lots, tracts, parcels or other divisions of land, including changes in existing lot lines for the purpose, whether immediate or future, of lease, partition by the court for distribution to heirs or devisees, transfer of ownership, or building or lot development; provided, however, that the subdivision by lease of land for agricultural purposes into parcels of more than 10 acres, not involving any new street, easement of access, or any residential dwelling, shall be exempted.
The smallest drainage unit of a watershed for which stormwater management criteria has been established in the stormwater management plan.
The Board of Supervisors of the Township of Derry, Dauphin County, PA.
A low-lying stretch of land that gathers or carries surface water runoff.
See "forest management."
The time for surface runoff to travel from the most hydraulically 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.
Township of Derry, Dauphin County, Pennsylvania.
The United States Department of Agriculture.
A channel or conveyance of surface water, such as a stream or creek, having defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
Region or area drained by a river, watercourse, or other surface water, whether natural or artificial.
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 the Commonwealth of Pennsylvania.
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, and which may be identified as jurisdictional wetlands using methods described in the current edition of the "Federal Manual for Identifying and Delineating Jurisdictional Wetlands."
[1]
Editor's Note: Chapter 92 of Title 25 of the Pennsylvania Code was reserved 10-8-2010, effective 10-9-2010. It was replaced by Chapter 92a, National Pollutant Discharge Elimination System (NPDES) Permitting, Monitoring and Compliance.
[2]
Editor's Note: Chapter 92 of Title 25 of the Pennsylvania Code was reserved 10-8-2010, effective 10-9-2010. It was replaced by Chapter 92a, National Pollutant Discharge Elimination System (NPDES) Permitting, Monitoring and Compliance.
[3]
Editor's Note: See 35 P.S. § 691.1 et seq.
[4]
Editor's Note: See 35 P.S. § 691.1 et seq.
[5]
Editor's Note: See 32 P.S. § 680.1 et seq.