Chapter 149 STORM WATER MANAGEMENT

Transcription

1 Chapter 149 STORM WATER MANAGEMENT ARTICLE I General Provisions Title Purpose; implication of provisions Legislative authority Applicability Compliance with other provisions required Township liability (Reserved) (Reserved) (Reserved) (Reserved) ARTICLE II Definitions and Word Usage Definitions and word usage (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) ARTICLE III Design Standards General requirements Stormwater management districts Methods of calculation of runoff Water-carrying facilities Detention and retention basins Erosion and sediment control Groundwater recharge and water quality standards (Reserved) (Reserved) (Reserved) ARTICLE IV Plan Requirements General requirements Exemptions Plan contents Subdivisions and land developments Other development activities (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) ARTICLE V Completion of Facilities or Guarantee Thereof Completion of facilities as part of subdivision or land development Determination of financial security. 149:

2 WEST EARL CODE Financial security for staged development Release of financial security Schedule of inspections Final inspection Failure to install facilities (Reserved) (Reserved) (Reserved) ARTICLE VI Maintenance or Stormwater Management Facilities Maintainenance of facilities during development Maintenance of facilities after development Maintenance of facilities accepted by township Maintenance of facilities not accepted by township Maintenance of facilities by private entity Maintenance of existing facilities Alteration of facilities Prohibited discharges Prohibitied connections Roof drains Waste disposal prohibitions. ARTICLE VII Administration and Enforcement Right of entry Revisions or alterations of stormwater management facilities Waivers or modifications of standards Violations Penalties and remedies Appeals Repealer. Appendix No. 1 PADOT Region 5 Storm IDG Database Appendix No. 2 Runoff Coefficients C for Rational Formula Appendix No. 3 Runoff Curve Numbers CN for SCS Method Appendix No. 4 Nomograph For Determining Sheet Flow Appendix No. 5 Worksheet No. 1: Time of Concentration (Tc) or Travel Time (Tt) Appendix No. 6 Average Velocities for Estimating Travel Time for Shallow Concentrated Flow Appendix No. 7 Manning n Values for Pipes Appendix No. 8 Certification Forms [HISTORY: Adopted by the Board of Supervisors of the Township of West Earl by Ord. No This ordinance also provided for the repeal of former Ch. 149, Stormwater Management, adopted by Ord. No. 41, as amended. Amendments noted where applicable.] 149:

3 149-I STORMWATER MANAGEMENT GENERAL PREFERENCES Sewers and sewage disposal See Ch. 138 Water See Ch Streets and sidewalks See Ch Zoning See Ch Subdivisions and land development See Ch ARTICLE I General Provisions Title. This chapter shall be known and may be cited as The West Earl Township Stormwater Management Ordinance Purpose; implication of provisions. A. The purpose of this chapter is to promote the public health, safety and welfare by establishing a comprehensive stormwater management program designed to: (I) Control accelerated runoff and erosion and sedimentation problems at their source by regulating activities which cause such problems. (2) Utilize and preserve the desirable existing natural drainage systems within the township. (3) Maintain the existing flows and quality of watercourses in the township and the commonwealth. (4) Preserve and restore the flood-carrying capacity of watercourses. (5) Provide for proper maintenance of all permanent stormwater management facilities which are constructed in the Township. B. This chapter does not imply that areas within or outside any identified flood-prone area will be free from flooding or flood damage Legislative authority. The Board of Supervisors of West Earl Township is empowered to regulate these activities by authority of the Act of October 4, 1978, P.L. 864, No. 167, known as the Stormwater Management Act, 1 and pursuant to the express and implied powers granted to the Board of Supervisors under the Second Class Township Code, Act of May 1, 1933, P.L. 103, No. 69, reenacted and amended November 9, 1955, P.L. 350, No. 60, as amended. 1. Editor s Note: See 32 P.S et seq. 149:

4 149-4 WEST EARL CODE Applicability. [Amended by Ord. No. 179] A. It shall be unlawful for any person to undertake any of the following activities without prior approval from the Township and without complying with all provisions, regulations, limitations amid restrictions of this chapter: (1) Development of any use within a flood-prone area as delineated by the Township Zoning Ordinance (Chapter 1 84). (2) Development of any commercial use, industrial use, multifamily dwelling unit, mobile home park, school, church, lodge, club or any other use determined by the Township to constitute a land development. (3) The creation of any subdivision. (4) Installation of any impervious cover not specifically exempted by Appendix 9 of this chapter. 2 The exemption criteria in Appendix 9 shall apply to the total proposed development on a parent tract even if development is to take place in stages. Impervious cover shall include, hut not be limited to, any roof, parking or driveway areas and any new streets and sidewalks. Any areas designed to initially be gravel or crushed stone shall be assumed to be impervious. [Amended by Ord. No. 191] (5) Diversion or piping of any natural or man-made stream channel. (6) Installations, alterations, modifications or tile removal of any existing or proposed stormwater runoff or management facilities or appurtenances thereto. (7) Land disturbance activity in excess of 10,000 square feet except for the agricultural use of land when operated in accordance with a farm conservation plan approved by the Lancaster County Conservation District. (8) Any other development where the Township determines that said development may adversely effect any existing watercourse, any existing stormwater management facilities, or any existing stormwater runoff patterns. B. It is the express intention of this section only to provide for Township review and approval of such activities tinder this chapter. This section shall not he interpreted to impair or limit the applicability of any other ordinance, regulation or statute, including but not limited to The Clean Streams Law, Chapter 102 of DEP s regulations, the Federal Clean Water Act, or NPDES requirements. All removal of ground cover, grading, filing or excavation, regardless of area, shall be performed in accordance with Chapter 102 and all other applicable statutes and regulations. 2. Editor s Note: Appendix 9 is included at the end of this chapter. 149:

5 149-5 STORM WATER MANAGEMENT Compliance with other provisions required. [Amended by Ord. No. 179; by Ord. No. 191] In the interpretation and application of the provisions of this chapter, said provisions shall be deemed to be the minimum requirements necessary for the promotion and protection of the public health, safety and welfare. Where the provisions of any statute, regulation, other Township ordinance or applicable land development agreement impose gm-eater restrictions upon development than this chapter, the provisions of this Chapter shall govern Township liability. [Amended by Ord. No. 179] Except as specifically provided by the Pennsylvania Stormwater Management Act, Act of October 4, 1978, P.L. 864, No. 167, as amended, 32 P.S et seq., the making of any administrative decision by the Township or any of its officials or employees shall not constitute a representation, guarantee or warranty of any kind by the Township of the practicability or safety of any proposed structure or use with respect to damage from erosion, sedimentation, stormwater runoff, flood, or any other matter, and shall create no liability upon or give rise to any cause of action against the Township and its officials and employees. The Board of Supervisors, by enacting and amending this chapter, does not waive or limit any immunity granted to the Township and its officials and employees by the Governmental Immunity Act, 42 Pa.C.S.A et seq., and does not assume any liabilities or obligations (Reserved) (Reserved) (Reserved) (Reserved) Definitions and word usage. ARTICLE II Definitions and Word Usage A. Words in the present tense include the future tense. Words in the singular include the plural, and words in the plural include the singular. The word buildings includes structures, and watercourse includes drain, ditch and stream. B. Unless otherwise stated, the following words shall, for the purpose of this chapter, have the meanings herein indicated: ACCELERATED EROSION - The removal of the surface of the land through the combined action of man s activities and natural processes at a rate greater than would occur because of the natural processes alone. 149:

6 WEST EARL CODE ACT The Stormwater Management Act, Act No. 167, October 4, 1978, P.L. 851, 3 as amended and supplemented, and all regulations promulgated thereunder. AGRICULTURE The cultivation of the soil and raising and harvesting of the products of the soil, including but not limited to nursery, horticulture, forestry and animal husbandry. ALLUVIAL SO1LS Soils formed from material such as gravel, sand or silt deposited by a stream of water and showing little or no modification of the original materials by soil-forming processes. These soils may be identified by the Soil Survey of Lancaster County, Pennsylvania, or through an on-site analysis. ALTERATION 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; also the changing of surface conditions by causing the surface to be more or less impervious; land disturbance. [Added by Ord. No. 179] APPLICABLE ACT 167 PLAN The Cocalico Creek Plan or the Conestoga River Plan, depending on the watershed in which the parent tract is located. [Added by Ord. No. 191] BMP (BEST MANAGEMENT PRACTICE) A type of stormwater management facility as set forth in of this chapter designed to improve the quality of stormwater runoff. [Added by Ord. No. 179] BOARD OF SUPERVISORS The Board of Supervisors of West Earl Township, Lancaster County, Pennsylvania. COCALICO CREEK ACT 167 PLAN The Cocalico Creek Watershed Stormwater Management Plan as approved by DEP. [Added by Ord. No CARBONATE GEOLOGY Limestone or dolomite bedrock. [Added by Ord. No. 179] CHANNEL A natural or artificial watercourse with a definite bed and banks which confine and conduct continuously or periodically flowing water. CHANNEL FLOW That water which is flowing within the limits of a defined channel. CISTERN An underground reservoir or tank for storing rainwater. CONESTOGA RIVER ACT 167 PLAN The Conestoga River Watershed Stormwater Management Plan as approved by DEP. [Added by Ord. No. 191] CONSERVATION PLAN A plan for agriculture land that includes maps and narrative and includes at a minimum an erosion and sedimentation control plan as 3. Editor s Note: See 32 P.S et seq. 149:

7 STORMWATER MANAGEMENT 149-Il required by Chapter 102 of the PA Clean Streams Law 4 and approved by Lancaster County Conservation District. CONSTRUCTION The construction, reconstruction, renovation, repair, extension, expansion, alteration or relocation of a building or structure, including the placement of mobile homes. 4. Editor s Note: See 35 P.S et seq. 149:

8 STORMWATER MANAGEMENT CONVEYANCE The ability of a pipe, culvert, swale or similar facility to carry the peak flow from the design storm. [Added by Ord. No. 179] CULVERT A structure with appurtenant works which carries a watercourse under or through an embankment or fill. DAM An artificial baffler, 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 dam falls under the requirements of Chapter 105, Dam Safety and Waterway Management, if the following is true: [Added by Ord. No. 179] (1) The contributory drainage area exceeds 100 acres. (2) The greatest depth of water measured by upstream toe of the dam at maximum storage elevation exceeds 15 feet. (3) The impounding capacity at maximum storage elevation exceeds 50 acre-feet. DEP The Department of Environmental Protection of the Commonwealth of Pennsylvania or any agency successor thereto. DESIGN STORM The magnitude of precipitation from a storm event measured in probability of occurrence (e.g., fifty-year storm) and duration (e.g., twenty-four-hour storm) and used in computing stormwater management control systems. DETENTION BASIN A basin designed to drain completely after retarding stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. DEVELOPER Any landowner, agent of such landowner or tenant with the permission of such landowner who makes or causes to be made a subdivision of land or a land development or other activities covered by this chapter. DEVELOPMENT Any man-made change to improved or unimproved real estate, including but not limited to buildings or other structures, mining, dredging, filling, grading, paving, excavation or drilling operations. DEVELOPMENT SITE The parent tract for which a regulated activity is proposed. A development site may also be referred to as a project site. [Added by Ord. No. 179] DISAPPEARING STREAM A stream in an area underlain by limestone or dolomite which flows underground for a portion of its length. [Added by Ord. No. 179] DOWNSLOPE PROPERTY LINE That portion of a property line of a parent tract located at the topographically lowest point of the tract such that some or all overland, swale, or pipe flow from a development site would be directed toward it. [Added by Ord. No. 179] 149:

9 WEST EARL CODE DRAINAGE CONVEYANCE FACILITY A stormwater management facility designed to transmit stormwater runoff and shall include streams, channels, swales, pipes, conduits, storm sewers, etc. [Added by Ord. No. 179] DRAINAGE EASEMENT A right granted by a landowner to a grantee allowing the use of private land for stormwater management purposes. EARTH DISTURBANCE See land disturbance. [Added by Ord. No. 179] ELEVATION The horizontal alignment of a surface, as it exists or as it is made by cut and/or fill. (1) LOWEST FLOOR The lowest floor of the lowest enclosed area, including basement. An unfinished or flood-resistant enclosure usable solely for parking of vehicles, building access and incidental storage, in an area other than the basement area, is not considered the lowest floor of a building, provided that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of Chapter 184. (2) ROAD GRADE The rate of rise and fall of a road surface, measured along the profile of the center of the cartway. ENGINEER A professional engineer registered by the Commonwealth of Pennsylvania. EPHEMERAL STREAM A water conveyance which lacks substrates associated with flowing waters and flows only in direct response to precipitation in the immediate watershed or in response to melting snowpack and which is always above the local water table. [Added by Ord. No. 179] EROSION The removal of soil particles by the action of water, wind, ice or other geological agents. EXISTING CONDITIONS The initial condition of a development site prior to the proposed construction. [Added by Ord. No. 179] FEMA The United States Federal Emergency Management Agency. FILL Material placed or deposited so as to form an embankment or raise the surface elevation of the land, including but not limited to levees, bulkheads, dikes, jetties, embankments and causeways. 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. [Added by Ord. No. 179] GRASSED WATERWAY A natural or constructed waterway, usually broad and shallow, covered with erosion-resistant grasses, used to conduct surface water from cropland. [Added by Ord. No. 179] 149:

10 STORMWATER MANAGEMENT GROUNDWATER RECHARGE Replenishment of existing natural underground water supplies. IMPERVIOUS SURFACE A surface which prevents the percolation of water into the ground. IMPOUNDMENT A retention or detention basin designed to retain stormwater runoff and infiltrate it into the ground (in the case of a retention basin) or release it at a controlled rate (in the case of a detention basin). [Added by Ord. No. 179] INFILTRATION STRUCTURES A structure designed to direct runoff into the ground. INLET A surface connection to a closed drain. The upstream end of any structure through which water may flow. [Added by Ord. No. 179] INTERMITTENT STREAM A body of water flowing in a channel or bed composed primarily of substrates associated with flowing water, which, during periods of the year, is below the local water table and obtains its flow from both surface runoff and groundwater discharges. [Added by Ord. No. 179] LAND DEVELOPMENT Any of the following activities: (1) The improvement of one lot or two or more contiguous lots, tracts or parcels of land for any purpose involving: (a) (b) 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 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. (2) A subdivision of land. (3) Development in accordance with the following shall be excluded from land development procedure: (a) (b) 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; or The addition of an accessory building, including farm buildings, on a lot or lots subordinate to an existing principal building. LAND DISTURBANCE Any activity involving grading, tilling, digging or filling of ground or stripping of vegetation or any other activity which causes land to be exposed to the danger of erosion. 149:

11 WEST EARL CODE LANDOWNER The legal, beneficial, equitable owner or owners of land, including the holder of an option or contract to purchase, a lessee if he is authorized under the lease to exercise rights of the landlord or other persons having a proprietary interest in land. LINEAMENT A fracture on the order of tens of kilometers long usually extending to the basement below sedimentary rock. [Added by Ord. No. 179] 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. [Added by Ord. No. 179] NATURAL DRAINAGEWAY An existing channel for water runoff that was formed by natural forces. [Added by Ord. No. 179] NRCS Natural Resources Conservation Service (previously SCS). [Added by Ord. No. 179] NONPOINT SOURCE POLLUTION Pollution that enters a body of water from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances. [Added by Ord. No. 179] OPEN CHANNEL 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 flowing partly full. [Added by Ord. No. 179] OUTFALL Point where water flows from a conduit, stream, or drain. [Added by Ord. No. 179] OUTLET Points of water disposal from a stream, river, lake, tidewater or artificial drain. [Added by Ord. No. 179] PADOT The Department of Transportation of the Commonwealth of Pennsylvania or any agency successor thereto. PARENT TRACT All contiguous land held in single and separate ownership, regardless of whether such land is divided into one or more lots, parcels, purparts or tracts; such land was acquired by the landowner at different times or by different deeds, devise, partition or otherwise; or such land is bisected by public or private streets or rights-of-way, which was held by the landowner or his predecessor in title on August 30, [Added by Ord. No. 179] PARKING LOT STORAGE Involves the use of impervious parking areas as temporary impoundments with controlled release rates during rainstorms. [Added by Ord. No. 179] PEAK DISCHARGE The maximum rate of flow of water at a given point and time resulting from a specified storm event. 149:

12 STORMWATER MANAGEMENT PIPE An enclosed water-carrying structure of one or more barrels having a total flow area equivalent to forty-eight-inch diameter or less. PLANNING COMMISSION The Planning Commission of West Earl Township, Lancaster County, Pennsylvania. POSITIVE DRAINAGE To draw off or empty surface waters in a manner which eliminates ponding, standing water or any other undesirable condition. For surface grades, a threshold of 1% shall determine positive drainage unless other means or facilities are provided to adequately drain surface waters. PROJECT SITE An area of land under development and within the jurisdiction of this chapter. REGULATED ACTIVITIES Any activity to which this chapter is applicable. [Added by Ord. No. 179] REGULATED ACTIVITY An action or proposed action that has an impact upon stormwater runoff and which is specified in of this chapter. [Added by Ord. No. 179] RETENTION BASIN A basin designed to retain stormwater runoff with its primary release of water being through the infiltration of said water into the ground. RETURN PERIOD The average interval, in years, within which a storm event of a given magnitude can be expected to recur. For example, the twenty-five-year return period rainfall would be expected to recur on the average once every 25 years. [Added by Ord. No. 179] 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. [Added by Ord. No. 179] ROOFTOP DETENTION Temporary ponding and gradual release of stormwater falling directly onto flat roof surfaces by incorporating controlled-flow roof drains into building designs. [Added by Ord. No. 179] RUNOFF That part of precipitation which flows over the land. SCS The Soil Conservation Service, United States Department of Agriculture (USDA). SEDIMENT Solid material, both mineral and organic, that is in suspension, is being transported or has been moved from its site or origin by water. SEDIMENTATION The process by which mineral or organic matter is accumulated or deposited by the movement of water. [Added by Ord. No. 179] SEDIMENT BASIN A barrier, dam or retention basin designed to retain sediment. SEDIMENT POLLUTION The placement, discharge or any other introduction of sediment into the waters of the commonwealth occurring from the failure to design, 149:

13 WEST EARL CODE construct, implement or maintain control measures and control facilities in accordance with the requirements of this chapter. [Added by Ord. No. 179] SEEPAGE PIT/SEEPAGE TRENCH An area of excavated earth filled with loose stone or similar material and into which stormwater runoff is directed for infiltration into the ground. SEMIPERVIOUS SURFACE A surface such as stone, rock or other materials which permits some vertical transmission of water into the ground. SHEET FLOW Runoff which flows over the ground surface as a thin, even layer, not concentrated in a channel. [Added by Ord. No. 179] SOIL-COVER COMPLEX METHOD A method of runoff computation developed by the SCS (now NRCS) that is based on relating soil type and land use/cover to a runoff parameter called curve number (CN). [Added by Ord. No. 179] SOIL GROUP, HYDROLOGIC A classification of soils by the SCS 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. [Added by Ord. No. 179] SOIL SURVEY REPORT The latest published version of the United States Department of Agriculture Soil Survey for Lancaster County. SPILLWAY A depression in the embankment of a pond or basin which is used to pass a postdevelopment one-hundred-year storm peak flow rate. [Added by Ord. No. 179] 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. [Added by Ord. No. 179] 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. [Added by Ord. No. 179] STORM SEWER A system of pipes, conduits, swales or other similar structures, including appurtenant works, which carries intercepted runoff and other drainage but excludes domestic sewage and industrial wastes. STORM WATER Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt. STORMWATER MANAGEMENT A program of controls and measures designed to regulate the quantity and quality of stormwater runoff from a development while promoting the protection and conservation of groundwater and groundwater discharge. STORM WATER MANAGEMENT FACILITIES Those controls and measures used to effect a stormwater management program. 149:

14 STORMWATER MANAGEMENT STREAM ENCLOSURE A bridge, culvert or other structure in excess of 100 feet in length upstream to downstream which encloses a regulated water of this commonwealth. [Added by Ord. No. 179] SUBDIVISION - The division or redivision or 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 paracels of more than 10 acres, not involving any new street or easement of access or any residential dwelling, shall be exempted. SUBSTRATES - Inorganic sediments which are 0.05 millimeter in diameter or larger and include sands, gravel, pebbles, cobbles and boulders, based upon Wentworth s Classification [Added by Ord. No. 179] SURFACE DRAINAGE PLAN - A plan showing all present and proposed grades and facilities for stormwater drainage. SWALE - A wide, shallow ditch which carries surface water runoff. 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. [Added by Ord. No. 179] TOWNSHIP - The Township of West Earl, Lancaster County, Pennsylvania. TR-20 (CALIBRATED) The Computer-based hydrologic modeling technique adapted to the watershed in which the subject property is located by the applicable Act 167 Plan -The model has been calibrated to reflect published and observed flow values by adjusting key input model parameters. [Added by Ord. No. 179; amended by Ord. No. 191] WATERCOURSE - A permanent or intermittent stream, river, brook, run, creek, channel, swale, pond, lake or other body of surface water carrying or holding surface water, whether natural or artificial. WATERSHED The entire region or area drained by a river or other body of water, whether natural or man-made. WATERS OF THE 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 and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of this commonwealth. [Added by Ord. No. 179] WETLANDS - Those 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, prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs and similar areas. 149:

15 WEST EARL CODE (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) (Reserved) General requirements. ARTICLE III Design Standards A. All stormwater management plans shall be designed and certified by individuals registered in the Commonwealth of Pennsylvania and qualified to perform such duties. B. Where applicable, stormwater management facilities shall comply with the requirements of Chapter 105 (Water Obstructions and Encroachments) of Title 25, Rules and Regulations, of the DEP. C. Stormwater management facilities which involve a state highway shall be subject to the approval of the PADOT. D. Stormwater management facilities located within or affecting the floodplain of any watercourse shall also be subject to the requirements of Chapter 184, Zoning, regulating construction and development within areas of the township subject to flooding. E. Stormwater runoff from a project site shall flow directly into a natural watercourse or into an existing storm sewer system or onto adjacent properties in a manner significantly similar to the runoff characteristics of the predevelopment flow. Concentration of post development stormwater runoff and direct overland discharge to adjacent properties 149:

16 STORMWATER MANAGEMENT is strictly prohibited. Maximum use shall be made of the existing on-site natural and manmade stormwater management facilities. F. Stormwater runoff shall not be transferred from one watershed to another unless the watersheds are subwatersheds of a common watershed which join together within the perimeter of the property, the effect of the transfer does not alter the peak discharge onto adjacent lands or drainage easements from the affected landowners are provided. G. All stormwater runoff flowing over the project site shall be considered in the design of the stormwater management facilities. H. When final plan applications are submitted in sections, and if temporary facilities are required for construction of a section, such facilities shall be included in the submitted plans for that section. In the event that temporary measures cannot adequately handle the stormwater runoff, the main outfall line and other required facilities shall be included as part of the construction of the proposed section. Each section shall provide adequate stormwater management facilities so that the peak discharge of the calculated postdevelopment runoff does not exceed 50% of the peak discharge of the calculated predevelopment runoff as outlined in B. I. Innovative methods of the detention and control of stormwater runoff may be used when approved by the township. Various combinations of methods should be tailored to suit the particular requirements of the type of development and the topographic features of the project site. The following is a partial listing of detention and control methods which can be utilized in stormwater management systems where appropriate: (1) Detention basins and retention basins. (2) Rooftop storage. (3) Parking lot ponding. (4) Seepage pits, seepage trenches or other infiltration structures. (5) Concrete lattice block surfaces. (6) Grassed channels and vegetated strips. (7) Cisterns and underground reservoirs. (8) Routed flow over grass. (9) Decreased impervious surface coverage. J. Construction of stormwater management facilities within carbonate areas shall be restricted and shall be provided only in accordance with the following guidelines: (1) Stormwater management facilities may be designed in carbonate rock areas only after an investigation by a qualified professional demonstrating that the site is suitable for the proposed stormwater management facilities. 149:

17 WEST EARL CODE (2) Detention/retention ponds shall be designed and constructed to provide a minimum of four feet of natural soils above any pinnacles bedrock, and all areas where there is evidence of subsurface voids or sinkholes shall be avoided. (3) Detention structures of low permeability are utilized. (4) All outflow from stormwater management facilities or directly from impervious surfaces shall have velocity dissipation and dispersed outfall into areas not underlain by carbonate rock and/or onto stable vegetative filter strip(s) and shall not be routed within 100 feet or any existing unremediated sinkholes; alternatively, outflow may be routed to a stable watercourse via a pipe or lined ditch or channel. (5) Underground stormwater detention facilities are prohibited in carbonate areas. (6) Open swales shall be lined with clay in all carbonate areas. (7) All stormwater piping shall have watertight joints. K. The following principles shall be applied to the design plan and construction schedule to minimize soil erosion and sedimentation: (1) Stripping of vegetation, grading or other soil disturbance shall be done in a manner which will minimize soil erosion. (2) Whenever feasible, natural vegetation shall be retained and protected. (3) The extent of the disturbed areas and the duration of its exposure shall be kept to a minimum, within practical limits. (4) Either temporary seeding, mulching or other suitable stabilization measures shall be used to protect exposed critical areas during construction. (5) Drainage provisions shall accommodate the stormwater runoff both during and after construction. (6) Soil erosion and sedimentation facilities shall be installed prior to any on-site grading. L. Storm drainage facilities shall be provided where necessary in order to drain low points along streets, to intercept storm runoff along streets at reasonable intervals and to permit the unimpeded flow of storm runoff along natural watercourses. Such facilities shall consist of inlets, manholes, pipes, headwalls and other facilities necessary for the collection and transportation of storm runoff. The township shall require the design calculations to be submitted for review by the Township Supervisors and the Township Engineer. M. Drainage facilities for drainage areas in excess of 1/2 square mile (320 acres) shall conform to the requirements of and be approved by the DEP. N. Where existing storm sewers are reasonably accessible, proposed developments shall be required, if necessary, to connect therewith. 149:

18 STORMWATER MANAGEMENT O. The applicant shall demonstrate that any facilities intended to be installed and located on an individual or group of individual lots can be adequately maintained by the homeowner(s) and/or lot owner(s). P. In areas of carbonate geology, a registered professional geologist shall certify the following: [Added by Ord. No. 179; amended by Ord. No. 191] (1) No stormwater facilities shall be placed in, over or immediately adjacent to the following features: (a) (b) (c) (d) (e) (f) (g) (h) Sinkholes. Closed depressions. Lineaments in carbonate areas. Fracture traces. Caverns. Intermittent streams. Ephemeral streams. Bedrock pinnacles (surface or subsurface). (2) Stormwater management basins shall not be located closer than 100 feet from the rim of sinkholes or closed depressions, nor within 100 feet from disappearing streams; nor shall these basins be located closer than 50 feet from lineaments or fracture traces; nor shall these basins be located closer than 25 feet from surface or identified subsurface pinnacles. (3) It shall be the developer s responsibility to verify if the development site is underlain by carbonate geology. Whenever a stormwater facility will be located in an area underlain by carbonate geology, a geological evaluation of the proposed location by a registered professional geologist shall be conducted to determine susceptibility to sinkhole formation. The developer shall include following note on the stormwater management plans which shall be signed and sealed by the developer s professional geologist: I,, certify that the proposed detention basin (circle one) is/is not underlain by carbonate geology. (4) Stormwater resulting from land development activities shall not be discharged into sinkholes. Q. Developers and/or landowners are encouraged to provide infiltration facilities or utilize other techniques which will allow the postdevelopment hydrograph to match the preexisting hydrograph, along all parts of the hydrograph, for the development site. This option is most feasible for small subdivisions in areas of noncarbonate geology. Groundwater recharge and water quality volumes as given in below can be used as part of this option. [Added by Ord. No. 179; amended by Ord. No. 191] 149:

19 WEST EARL CODE R. The developer shall include a note on a sheet of the plan to be recorded which grants the Township the right of access to all stormwater management easements on the development site via the access drives, driveways, parking areas, and similar features within the development site. [Added by Ord. No. 191] Stormwater management districts. The township shall comply with the applicable provisions of the Stormwater Management Act, Act No. l67,~ as amended upon adoption of the Stormwater Management Plan by the Lancaster County Planning Commission. If the provisions of this chapter are sufficient to regulate development within the township in a manner consistent with the Stormwater Management Act, this chapter shall be deemed to satisfy the requirement of Section 11(b) of Act 167 without the necessity of reenactment Methods of calculation of runoff. A. The methods of computation used to determine peak discharge and runoff shall be: (1) The USDA Soil Conservation Service Soil-Cover-Complex Method, as set forth in the latest edition of Urban Hydrology for Small Watersheds, Technical Release No. 55, as published by SCS. If the Soil-Cover-Complex Method is used, stormwater runoff shall be based on the following twenty-four-hour storm events: Storm Event Rainfall (years) (inches) (2) The Rational Method. (a) The Rational Method is as follows: Q = CIA Where: Q = The peak discharge of the watershed in cubic feet per second. C = The coefficient of runoff. 5. Editor s Note: See 32 P.S et seq. 6. Editor s Note: See 32 P.S (h). 149:

20 STORMWATER MANAGEMENT I = The intensity of rainfall in inches per hour. A = The area of the watershed in acres. (b) If the Rational Method is used, Region 5, Pennsylvania Rainfall Intensity-Duration- Frequency Chart shown in the PADOT Design Manual, 149:

21 STORMWATER MANAGEMENT Part 2, August 1981, shall be used to determine the rainfall intensity in inches per hour. This chart is attached hereto as Appendix No. 1 and is made a part hereof. 7 B. Runoff calculations shall include a hydrologic and hydraulic analysis indicating volume and velocities of flow and the grades, sizes and capacities of water-carrying structures, sediment basins and retention and detention structures and sufficient design information to construct such facilities. Runoff calculations shall also indicate both predevelopment and postdevelopment rates for peak discharge of stormwater runoff from the project site. C. For the purpose of calculating on-site peak discharges, all cultivated and tilled lands shall be considered to be cultivated land with conservation measures in good hydrologic condition, and all pasture or meadowlands shall be considered to be in good hydrologic condition. Runoff coefficients for off-site discharges shall be based on actual land use assuming winter or poor land conditions. D. Criteria and assumptions to be used in the determination of stormwater runoff and design of management facilities are as follows: (1) Runoff coefficients should be based on the information contained in Appendix Nos. 2 and 35 if the actual land use is listed in those Appendixes. If the actual land use is not listed in these Appendixes, runoff coefficient shall be chosen from other published documentation, and a copy of said documentation should be submitted with the stormwater management report. (2) Times of concentration shall be based on the following design parameters: (a) Sheet flow. The maximum length for each reach of sheet or overland flow before shallow concentrated or open channel flow develops is 150 feet. Sheet flow may be determined using the nomograph in Appendix No. 4, or the Manning s kinematic solution shown in the sheet flow section of Worksheet No. 1 in Appendix No (b) Shallow concentrated flow. Travel time for shallow concentrated flow shall be determined using Figure 3-1 from the TR-55, urban hydrology for small watersheds, as shown in Appendix No. 6. A sample worksheet for calculating times of concentration is provided in Appendix No (c) Open channel flows. At points where sheet and shallow concentrated flows concentrate in field depressions, swales, gutters, curbs or pipe collection systems, the travel times and downstream end of the site between these design points shall be based upon Manning s Equation and/or acceptable engineering design standards as determined by the Township Engineer. 7. Editor s Note: Appendix No. 1 is located at the end of this chapter. 8. Editor s Note: Appendix Nos. 2 and 3 are located at the end of this chapter. 9. Editor s Note: Appendix Nos. 4 and 5 are located at the end of this chapter. 10. Editor s Note: Appendix No. 5 is located at the end of this chapter. 149:

22 WEST EARL CODE Water-carrying facilities. A. All storm sewer pipes, open channels, swales and other water-carrying facilities (excluding detention and retention basins) conveying stormwater originating only from within the boundaries of the project site shall be designed for a twenty-five-year storm event. B. All storm sewer pipes, open channels, swales to the water-carrying facilities (excluding detention and retention basins) conveying water originating from off site shall be designed for a fifty-year storm event. C. All storm sewer pipes, open channels, swales and other water-carrying facilities which are required to convey water to control facilities (detention and retention basins) shall be designed for a onehundred-year storm event. Stormwater which bypasses such conveyance facilities during a onehundred-year storm event shall be considered undertained. D. All developments shall include design provisions that allow for the overland conveyance of the postdevelopment one-hundred-year storm event flows through the site without damage to any private or public property. E. Stormwater flowing to and through adjacent properties from the development site shall be enclosed in an easement and acknowledged by the adjacent property owner if the post-condition is not consistent with the pre-condition. F. All storm sewer pipes, culverts, manholes, inlets, end walls and end sections shall be constructed in accordance with PADOT Form 408, as amended. Water-tight joints shall be provided if the township deems appropriate. G. Storm sewer pipes, culverts, manholes, inlets, end walls and end sections proposed for dedication or located along streets shall conform to the requirements of the PADOT, Bureau of Design, Standards for Roadway Construction, Publication No. 72, in effect at the time the design is submitted, as modified by the adopted township construction standards. H. Storm sewer pipes and culverts shall have a minimum diameter of 15 inches and shall be made of reinforced concrete pipe (RCP), corrugated galvanized metal pipe (CMP) or plastic pipe equal to ABS N- 12. Sewers shall be installed on sufficient slopes to provide a minimum velocity of three feet per second when flowing full. I. A trash rack shall be provided on the upstream side of all storm sewer pipes regardless of pipe size. J. All storm sewer pipe shall be laid to a minimum depth of one foot from the subgrade to the crown of the pipe in paved areas and one foot from finished grade to the crown of pipe in grassed areas. K. Headwalls, end walls and end sections shall be used where stormwater runoff enters or leaves the storm sewer horizontally from a natural or man-made channel. PADOT Type DW headwalls and endwalls shall be utilized. Curves in pipes or box culverts without an inlet or manhole are prohibited. Tee joints, elbows and wyes are also prohibited. 149:

23 STORMWATER MANAGEMENT L. The capacity of storm sewers shall be calculated for both steady flow and culvert design. The lower value of the two shall be used to determine the capacity of the storm sewer. M. Inlets shall be placed on both sides of the street at low spots, at a maximum of 600 feet apart along a storm sewer pipe, at points of abrupt changes in the horizontal or vertical directions of storm sewers and at points where the flow in gutters exceeds three inches. Inlets shall normally be along the curbline at or beyond the curb radius points. For the purpose of inlet location at corners, the depth of flow shall be considered for each gutter. At intersections, the depth of flow across the through streets shall not exceed one inch. Inlets shall be depressed one inch below the grade of the gutter or ground surface. Manholes may be substituted for inlets at locations where inlets are not required to handle surface runoff. Inlets shall not be placed in areas other than street and parking lots, unless otherwise approved by the township. N. Stormwater roof drains and pipes, wherever possible, shall discharge water into a stormwater runoff dispersion and infiltration control device and not into storm sewers or street gutters. 0. Inlets, culverts and basin discharge systems shall be designed for the worst case condition. Inlet capacity shall be based on design data provided by the manufacturers and accepted by the township. If acceptable information is not available, inlets in nonponding areas shall be designed for a maximum capacity of four cubic feet per second (cfs). Where ponding occurs, inlet capacity shall be based on accepted engineering design practices. Culvert design shall consider either inletloutlet control or a combination of hydraulic losses through the system, whichever is greater. Basin discharge systems shall be designed to the same standards as culverts. If it cannot be readily determined which hydraulic condition controls, the basin discharge rate shall be based on the highest possible discharge rating curve, and the basin capacity shall be sized to store the excessive storm runoff based on the lowest possible discharge rating curve. P. All existing and natural watercourses, channels drainage systems and areas of surface water concentration shall be maintained in their existing condition unless an alteration is approved by the township. Q. Flow velocities from any storm sewer may not result in a deflection or erosion of the receiving channel. R. The velocity to be used in the design of a piped stormwater conveyance system shall be based on the maximum velocity obtainable. The capacity shall be based upon full flow conditions. S. The capacities of open channels shall be computed from the Manning Equation. Permissible openchannel velocities and design standards shall be in accordance with good engineering practice as documented in the Engineering Field Manual for Conservation Practices, USDA, SCS or in Design Charts for Open-Channel Flow, Hydraulic Design Series No. 3, United States Department of Transportation. T. Curb, gutter and roadside swale depths shall comply with the following requirements: 149:

24 WEST EARL CODE (1) If a proposed lot or development site is to be graded so as to redirect postdevelopment flow into an existing gutter or swale along an existing street where no curbs exist, or when an existing gutter or swale is to be integrated into the proposed stormwater conveyance system, a maximum depth of six inches shall be permitted in the roadside gutter or swale. (2) All new streets with curbs shall be designed to maintain a maximum depth of flow of three inches along curbs. All driveway intersections shall be designed so that flows do not enter the site from the adjacent street and that no additional flows are diverted onto the adjacent street from the site. (3) The depth of flow across street intersections, including new street intersections with existing streets, shall be a maximum of one inch. U. Stormwater roof drains, sump pumps and pipes shall not directly discharge water into a street rightof-way or sanitary sewer. V. Energy dissipators shall be placed at the outlets of all storm sewer pipes, culverts and bridges where flow velocities exceed maximum permitted channel velocities. W. The following conditions shall be met for all swales: (1) Capacities and velocities shall be computed using the Manning Equation. The design parameters shall be as follows: (a) Vegetated swales. [1] For vegetated swales, two design considerations shall be met: [a] The first shall consider channel velocity and stability based upon a low degree of retardance (n equals 0.03). [b] The second shall consider channel capacity based upon a high degree of retardance (n equals 0.05). [2] All vegetated swales shall have a minimum slope of 1% unless otherwise approved by the township. (b) The Manning n factors to be used for paved or rip-rap swales or gutters shall be based upon accepted engineering design practices as approved by the township. In general, it is the intent of this chapter to discourage the use of rip-rap swales due to the difficulty experienced in preventing excessive growth of weeds within the swales. (2) All swales shall be designed to concentrate low flows to minimize siltation and meandering. (3) The maximum swale and gutter velocity of stormwater runoff shall be maintained at levels which result in a stable condition both during and after construction. The following are considered characteristics of a stable condition: 149:

25 STORMWATER MANAGEMENT (a) It neither aggrades or degrades beyond tolerable limits. (b) The channel banks do not erode to the extent that the channel cross section is changed appreciably. (c) (d) (e) Sediment bars do not develop. Erosion does not occur around culverts and bridges or elsewhere. Gullies do not form or enlarge due to the entry of stormwater runoff. (4) Grass lined channels shall be considered stable if the calculated velocity does not exceed the allowable velocities shown below: (a) (b) (c) Three feet per second where only sparse Vegetation can be established and maintained because of shade or soil condition. Four feet per second where normal growing conditions exist and vegetation is to be established by seeding. Five feet per second where a dense, vigorous sod can he quickly established or where water can be temporarily diverted during establishment of vegetation. Netting and mulch or other equivalent methods for establishing begetation shall be used. (d) Six feet per second where there exists a well-established sod of good quality. (5) Where swale bends occur, the allowable velocities listed above shall be divided by the following factors: (a) Swale bends 0 to 30 : (h) Swale bends 30 to 60 : (c) Swale bends 60 to 90 : (d) Swale bends 90 and over: (6) These calculated grass hued channel flows may be exceeded if the designer can provide acceptable supportive design criteria as proof of erosion prevention. (7) Where the velocity of stormwater runoff exceeds the allowable velocity, erosion protection must be provided. The method of erosion protection proposed must he supported by the appropriate design information and/or references. X. Manning n values used for design of pipes and culverts shall he in accordance with Appendix No Y. All storm sewer crossings of streets shall be perpendicular to the street center line. 11. Editor s Note: Appendix No. 7 is located at the end of this chapter 149:

26 l49-24 WEST EARL CODE Z. Storm facilities not located within public rights-of-way shall be centered within easements. AA. All stormwater structures which discharge from residential lots to storm sewer systems within street rights-of-way, or from a street to residential lots, shall extend from the street right-of-way to a minimum distance of 2/3 the length of the longest adjacent lot dimension, or to the rear of the dwelling, whichever is greater. BB. Drainage easements shall be provided to contain and convey the one-hundred-year-storm-frequency flood throughout the project site. Easements shall begin at the furthest upstream property line of the proposed development in a watershed. The minimum width of any easement shall be 20 feet. Additional width may be required by the township depending on the purpose and use of the easement. Stormwater facilities shall be centered within easements. CC. Where a development is traversed by a watercourse, drainageway, channel or stream, there shall be provided a drainage easement conforming substantially with the line of such watercourse, drainageway, channel or stream and of such width as will be adequate to preserve the unimpeded flow of natural drainage or for the purpose of widening, deepening, relocating, improving or protecting such drainage facilities. DD. Any changes in an existing drainageway shall comply with the Zoning Ordinance, Chatper 184, and shall be subject to the approval of the DEP, Water and Power Resources Board, Division of Dams and Encroachments, when the Board has jurisdiction. EE. A minimum of a twenty-foot-wide easement shall be provided along any storm sewer not located within a public right-of-way. FF. Stormwater conveyance improvements. If the developer can prove under the no-harm option of the applicable Act 167 plan that it would be feasible to provide conveyance improvements (install or upgrade pipes, bridges, swales, etc.) to relieve existing deficiencies, the developer may provide the conveyance improvements in lieu of stormwater management facilities on the development site. Any conveyance improvements shall be designed based on the eventual development of all areas tributary to the improvements and the conveyance criteria specified in this chapter. The eventual development of all tributary areas that the developer must consider shall either be based on the current zoning or be established by the Township, whichever results in a greater amount of impervious surface. It shall be assumed that all new development upstream of proposed conveyance improvement would implement applicable stormwater management techniques consistent with this chapter. For the purposes of this subsection, an existing deficiency shall be considered existing stormwater conveyance facilities which do not meet existing Township, state or federal regulations or existing stormwater management facilities which cannot convey water originating only from within the boundaries of the development site generated by a twenty-five-year storm event or which cannot convey water originating from off the development site for a fifty-year storm event. [Added by Ord. No. 179; amended by Ord. No. 191] 149:

27 STORMWATER MANAGEMENT Detention and retention basins. A. Stormwater management control facilities (i.e., detention and retention basins) shall be provided so that the peak discharge of the calculated postdevelopment runoff to an adjacent property does not exceed 50% of the predevelopmnent peak discharge for all design storms (two-, five-, ten-, twentyfive-, fitfy- and one-hundred-year storm events). [Amended by Ord. No. 179] B. The calculated peak discharge for stormwater originating on the project site must meet the following conditions, for all watersheds flowing from the project site: (1) The two-year postdevelopment peak discharge must be less than or equal to 50% of the twoyear predevelopment peak discharge. (2) The ten-year postdevelopment peak discharge must be less than or equal to 50% of the tenyear predevelopment peak discharge. (3) The twenty-five-year postdevelopment peak discharge must he less than or equal to 50% of the twenty-five-year predevelopment peak discharge. (4) The fifty-year postdevelopment peak discharge must be less than or equal to 50% of the fiftyyear predevelopment peak discharge. (5) The one-hundred-year postdevelopment peak discharge must be less than or equal to 50% of the one-hundred-year predevelopment peak discharge. C. The maximum water depth shall not exceed six feet. D. The minimum top width of all dams shall be five feet. E. The side slopes shall not be less than three horizontal to one vertical. F. All basins shall be structurally sound and shall be constructed of sound and durable materials. The completed structure and the foundation of all basins shall be stable under all probable conditions of operation and shall be capable of discharging the peak discharge of a postdevelopment one-hundredyear storm event through the emergency spillway facilities in a manner which will not damage the integrity of the facility or the downstream drainage areas. Where practical, the emergency spillway shall be constructed in undisturbed ground. An easement shall be provided from the spillway to a natural or artificial watercourse. G. The effect on downstream areas if the basin embankment fails shall be considered in the design of all basins. Where possible, the basin shall be designed to minimize the potential damage caused by such failure of the embankment. H. All outlet structures and emergency spillways shall include a satisfactory means of dissipating the energy of flow at its outlet to assure conveyance of flow without endangering the safety and integrity of the basin and the downstream drainage area. I. All groundwater recharge facilities shall be designed to empty in 48 hours subsequent to any storm event. All water quality facilities shall be designed so that water is released slowly for a minimum of 24 hours subsequent to any storm event. All infiltration, 149:

28 WEST EARL CODE detention or retention facilities used for storm water management (pre vs. post) shall be designed to empty within 24 hours subsequent to any storm event. [Amended by Ord. No. 179; by Ord. No. 191] J. A cutoff trench of relatively impervious material shall be provided within all basin embankments. K. All structures passing through basin embankments shall be concrete, shall have properly spaced concrete cutoff collars and O-ring rubber gaskets. L. All discharge control devices and piping with appurtenances shall be made of reinforced concrete and stainless steel. M. A minimum one-foot freeboard above the maximum design water surface elevation at the emergency spillway shall be provided. N. Detention basins other than those designed to incorporate groundwater recharge and/or water quality features shall be provided with low-flow channels from each water-carrying facility to the outlet structure. Low-flow channels shall have a minimum of 1% slope and shall be designed to enable ease of maintenance. Detention basins designed to incorporate groundwater recharge and/or water quality features may have flat bottoms if appropriate basin planting for both wet and dry conditions and a maintenance program is provided. [Amended by Ord. No. 191] 0. Design storms for the computation of retention basins (where approved) volumes shall be based upon a twenty-four-hour storm. P. A trash rack shall be provided for all orifices regardless of pipe size on the upstream side of outlet structures. Q. In areas underlain with carbonate geology, ponds shall be limited to the detention (dry) type ponds unless the developer can show a special need for a retention pond, in which case it shall have a lining. Detention ponds shall be prohibited in areas of known sinkholes unless the pond is lined. If a sinkhole develops in a pond or channel before acceptance by the township, a lining shall be required. R. When permanent stormwater detention basins are designed to be used as sedimentation basins during the construction of a development, all stormwater control devices, such as orifice plates, shall be installed before and during construction to control stormwater during this period. S. Minimum floor elevations, including basements for all structures that would be affected by a basin, other temporary impoundments or open conveyance systems where ponding may occur, shall be two feet above the one-hundred-year water surface elevation. If basement or underground facilities are proposed, detailed calculations addressing the effects of stormwater ponding on the structure and waterproofing and/or floodproofing design information shall be submitted for approval. 149:

29 STORMWATER MANAGEMENT Erosion and sediment control. A. All earthmoving activities shall he conducted in such a way as to minimize accelerated erosion and resulting sedimentation. Measures to control erosion and sedimentation shall, at a minimum, meet the standards of the Lancaster County Conservation District and Chapter 102 (Erosion Control) of Title 25, Rules and Regulations of the DEP. B. The erosion and sedimentation control plan must be available at all times at the project site. When required, a permit allowing earthmoving activity shall be obtained by the developer before any construction on the project site shall begin. C. Approval of an erosion and sedimentation control plan by the township shall not be construed as an indication that the plan complies with the standards of any agency of the commonwealth. D. In order to prevent pollution of any watercourse and to reduce erosion of soil, sediment control devices shall be installed prior to any grading, filling or excavation. Such devices shall be designed to retain sediment on the site. F. Calculations should be provided verifying the sizing of all erosion control facilities. F. The erosion and sedimentation control plan shall be submitted to the Lancaster County Conservation District for its review and approval Groundwater recharge and water quality standards. [Added by Ord. No. 179; amended by Ord. No. 191] Developers shall meet all of the standards set forth in this section in addition to all other requirements of this chapter. To the extent that a requirement of this section is different than a requirement of another section of this chapter concerning the same item, the requirements of this section shall apply. A. Match preexisting hydrograph. Developers and/or landowners are encouraged to provide infiltration facilities or utilize other techniques which will allow the postdevelopment hydrograph to match the preexisting hydrograph, along all parts of the hydrograph, for the development site. This option is most feasible for small subdivisions in areas of noncarbonate geology. Groundwater recharge and water quality volumes as given in C and l49-27d below can be used as part of this option. B. Detention/infiltration standards. Postdevelopment rates of runoff from any regulated activity shall not exceed 50% of the peak rates of runoff prior to development for all design storms unless the preexisting hydrograph is not exceeded at all points in time. C. Groundwater recharge. (1) Developed areas shall maintain groundwater recharge consistent with predevelopment conditions, dependent on hydrologic soil groups and impervious cover unless the developer can prove the inability of the development site to achieve recharge based on existing development site conditions. This volume of runoff is termed the recharge volume and is calculated in accordance with H. The recharge volume must be infiltrated within 48 hours after the end 149:

30 WEST EARL CODE of the design storm. Development sites where the postdeveloped impervious area is equal to or less than the predeveloped impervious area shall not be required to provide groundwater recharge volume. (2) Design of the stormwater management facilities shall provide for groundwater recharge to compensate for the reduction in the percolation that occurs when the ground surface runoff characteristics have been altered. A detailed geologic evaluation of the development site shall be performed to determine the suitability of recharge facilities. The evaluation shall be performed by a registered professional geologist, and shall, at a minimum, address soil permeability, depth to bedrock, susceptibility to sinkhole formation, and subgrade stability. Where pervious pavement is permitted for parking lots, recreational facilities, nondedicated streets, or other areas, pavement construction specifications shall be noted on the plan. (3) If the developer can prove through analysis that the development site is in an area underlain by carbonate geology, and such geologic conditions may result in sinkhole formations, then the development site is exempt from recharge requirements. The development site shall still be required to meet all other hydrologic and water quality management standards as found in this chapter. D. Water quality. Developed areas will provide adequate storage and treatment facilities necessary to capture and treat a minimum of the runoff from the first 1.2 inches of rainfall. This volume of storage is the water quality volume and is calculated in accordance with The recharge volume may be a component of the water quality volume. If the recharge volume is less than the water quality volume, the remaining water quality volume may be captured and treated by methods other than recharge/infiltration BMPs. The water quality volume must take a minimum of 24 hours to be discharged. Development sites where the postdeveloped impervious area is equal to or less than the predeveloped impervious area shall not be required to provide water quality volume unless required by NPDES Part II. E. Stormwater conveyance corridor protection (riparian corridor preservation and vegetation). Runoff from developed areas of the development site, including hut not limited to areas of impervious surface, shall be managed through a series of riparian corridor vegetation facilities whenever possible. This will be accomplished in a manner satisfactory to the Township utilizing the Pennsylvania Handbook of Best Management Practices for Developing Areas, 1998, Riparian Forested Buffer, and the priority goal of the riparian vegetation will be the reduction of the thermal impacts on stormwater runoff associated with impervious areas, with a secondary goal being the protection of capacity of existing stormwater conveyance channels. These goals will be achieved through the use of design criteria in Article III of this chapter and shall be in addition to any other Township ordinance provisions. F. Subregional (combined development site) storage. Runoff can be managed regionally by one or more developers, either on site or off site. The design and release rate shall be consistent with the applicable Act 167 plan. Groundwater recharge and water quality volumes as described in C and D will be a part of this option. 149:

31 STORM WATER MANAGEMENT G. No-harm option. (1) The no-harm option does not apply to the water quality requirement described in l49-27d above. The no-harm option does not apply to the groundwater recharge requirement described in C above, unless it can he shown that the development site is underlain by carbonate geology and infiltration cannot be safely accomplished. (2) For any proposed development, the developer has the option of using a less restrictive runoff control if the developer can prove that no harm would be caused by discharging at a higher runoff rate than that specified by the applicable Act 167 plan. Proof of no harm would have to be shown from the development site through the remainder of the downstream drainage network until there is no additional flow increase. Proof of no harm must be shown using the capacity criteria specified in l49-27c if downstream capacity analysis is a part of the noharm justification. (3) Attempts to prove no harm based upon downstream peak flow versus capacity analysis shall be governed by the following provisions: (a) The peak flow values to be used for downstream areas for the design return period storms (two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year) shall be the values from the calibrated TR-20 Model for the applicable Act 167 plan. (b) At peak flow, any available capacity in the downstream conveyance system (as documented by a developer) may be used only in proportion to the proposed development site acreage relative to the total upstream undeveloped acreage (i.e., if the development site is 10% of the upstream undeveloped acreage, the developer may use up to 10% of the documented downstream available capacity at peak flow). (c) Developer-proposed runoff controls which would generate increased peak flow rates at documented storm drainage problem areas would, by definition, be precluded from successful attempts to prove no harm, except in conjunction with proposed capacity improvements for the problem areas consistent with this section. (4) Any no-harm justifications shall be submitted by the developer as part of the application. H. Groundwater recharge requirements. (1) The groundwater recharge volume (Rev) is the volume of stormwater runoff from a developed site which shall be required to maintain existing predevelopment groundwater recharge at the development site. It may be part of the water quality volume and is calculated on the basis of treatment and recharge by structural stormwater management practices, as follows: Re V = [(S) (R V )(A)] /12 149:

32 WEST EARL CODE Re V = Recharge volume in acre-feet A = Area of watershed in acres R V = (I) where I = net increase in impervious area/area of watershed (A) S is the soil specific recharge factor and varies according to soil type, as follows: Hydrologic Soil Group Soil Specific Recharge Factor (S) A 0.32 B 0.22 C 0.10 D 0.05 (2) If more than one hydrologic soil group (HSG) is present at a development site, a composite recharge volume shall be computed based upon the proportion of total development site area within each HSG. (3) Infiltration BMPs intended to receive runoff from developed areas shall be selected based on suitability of soils and development site conditions and shall be constructed on soils that have the following characteristics: (a) (b) A minimum depth of 48 inches between the bottom of the facility and the seasonal highwater table and/or bedrock (limiting zones). An infiltration and/or percolation rate sufficient to accept the additional stormwater load and drain completely as determined by field tests conducted by the developers professional designer. (4) Infiltration BMPs receiving only roof runoff may be placed in soils having a minimum depth of 24 inches between the bottom of the facility and the limiting zone. (5) The recharge volume provided at the development site shall be directed to the most permeable HSG available. (6) Structural stormwater management facilities which provide treatment and recharge of the required recharge volume will be designed as part of a stormwater management facility which incorporates groundwater recharge BMPs as a primary benefit of using that facility, in accordance with design specifications contained in Pennsylvania Handbook of Best Management Practices for Developing Areas, (7) The groundwater recharge volume shall be infiltrated within 48 hours after the end of the design storm. (8) Development sites where the postdeveloped impervious area is equal to or less than the predeveloped impervious area shall not be required to provide groundwater recharge volume. 149:

33 STORMWATER MANAGEMENT I. Calculation of water quality volume. (1) The water quality volume (WQ~) is the storage capacity needed to treat stormwater runoff equivalent to a minimum of the first 1.2 inches of runoff from the developed areas of the development site. The following calculation is used to determine the storage volume, WQ~, in acre-feet of storage: WQ V = [(1.2) (R V )(A)] / 12 WQ V = Water quality volume in acre-feet A = Area of watershed in acres R V = (I) where I = net increase in impervious area/area of watershed (A) (2) WQ V shall be designed as part of a stormwater management facility which incorporates water quality BMPs as a primary benefit of using that facility, in accordance with design specifications contained in Pennsylvania Handbook of Best Management Practices for Developing Areas, The water quality volume shall take a minimum of 24 hours to be discharged from the basin. Development sites where the postdeveloped impervious area is equal to or less than the predeveloped impervious area shall not be required to provide water quality volume, unless required by NPDES Part II (Reserved) (Reserved) (Reserved) General requirements. ARTICLE IV Plan Requirements Prior to the final approval of any subdivision or land development plan, the issuance of any permit or the commencement of any development within the jurisdiction of this chapter, the developer shall submit a stormwater management plan to the township for approval Exemptions. The following activities are specifically exempt from the plan requirements of this chapter: 149:

34 WEST EARL CODE A. Use of land for gardening and landscaping of the property. B. Agriculture, when operated in accordance with a conservation plan or erosion and sedimentation control plan approved by the Lancaster County Conservation District. C. Any other activity that the developer has shown to the satisfaction of the township that the proposed activity would not adversely affect an existing watercourse, any existing stormwater runoff patterns and would not violate the intent of this chapter Plan contents. The following items shall be included as part of the stormwater management plan: A. Plans showing the following information on sheet sizes consistent with Chapter 155, Subdivision and Land Development: (1) General. (a) (b) (c) The proposed name or the identifying title of the project. The names and addresses of the landowner and the developer of the project site. The plan date and the date of the latest revision to the plan, North point, graphic scale and written scale. All plans shall be at a scale of 20, 50 or 100 feet to the inch. (d) The total acreage of the project site and the tract of land on which the project site is located. (e) A location map, for the purpose of locating the project site to be developed, at a minimum scale of 2,000 feet to the inch, showing the relation of the tract to adjoining property and to all streets and township boundaries existing within 1,000 feet of any part of the tract of land on which the project site is proposed to be developed. (f) A seven-and-one-half-minute USGS topographic map, or equivalent, showing the project location and its total watershed(s) and additional maps as necessary to clearly show the delineation of all drainage areas, both on site and off site, used in all stormwater runoff computations for all stormwater management facilities and all storm drainage facilities. (g) A certificate for approval by the Board of Supervisors. See Appendix No (h) A certificate for review by the township Planning Commission. See Appendix No Editor s Note: Appendix No. 8 is located at the end of this chapter. 13. Editor s Note: Appendix No. 8 is located at the end of this chapter. 149:

35 STORMWATER MANAGEMENT (i) A certificate for review by the Township Engineer if required by the Board of Supervisors. See Appendix No (2) Existing features. (a) Tract boundaries showing distances, bearings and curve data, as located by field survey or by deed plotting. (b) Existing contours at vertical intervals of two feet for land with an average natural slope of 4% or less and at vertical intervals of five feet for more steeply sloping land, except that for residential and agricultural uses where a preliminary subdivision or land development plan is not required by Chapter 155, Subdivision and Land Development, no contours shall be required; however, the plan should indicate the natural drainage patterns of the site, along with the approximate grades of all slopes. Where contours are shown, the location of the benchmark and the datum used shall also be indicated. (c) The names of all owners of all immediately adjacent unplatted land, the names of all proposed or existing developments immediately adjacent and the locations and dimensions of any streets or easements shown thereon. (d) The names, locations and dimensions of all existing streets, railroads, watercourses, drainage facilities, floodplains and other significant features within 200 feet of any part of the tract proposed to be developed and the location of all buildings and approximate location of all tree masses within the tract. (e) Soil types as designated by the USDA SCS Soil Survey of Lancaster County. (3) Proposed features. (a) The proposed land use, the number of lots and dwelling units and the extent of commercial, industrial or other nonresidential uses. (b) The locations and dimensions of all proposed streets, parks, playgrounds and other public areas; sewer and water facilities; lot lines and building locations; and parking compounds and other impervious and semipervious surfaces. (c) The proposed changes to the land surface and vegetative cover, including areas to be cut or filled. (d) Final contours at vertical intervals of two feet for land with an average natural slope of 4% or less and at vertical intervals of five feet for more steeply sloping land. Where existing contours are not shown or where proposed contour lines cannot be accurately located (i.e., as in a single-family detached residential development when the building has not been determined), arrows indicating general surface runoff flow patterns shall be shown. 14. Editor s Note: Appendix No. 8 is located at the end of this chapter. 149:

36 WEST EARL CODE (e) Finished elevations on tops of curbs at lot lines projected and lot corners. Elevations shall be shown to the nearest tenth of a foot. (4) Stormwater management facilities. (a) All storm sewers, along with any proposed connections to existing facilities. (b) Groundwater recharge methods such as seepage pits, beds or trenches. When these structures are used, the locations of infiltration areas and wells must be shown. (c) Other control devices or methods such as rooftop storage, grass swales, parking lot ponding, vegetated strips and detention or retention basins. (d) Plans and profiles of all proposed stormwater management facilities, including vertical and horizontal alignment, size and type of material. This information shall be of the quality required for the construction of all facilities. All swales and open channels shall have center line invert elevations shown every 100 feet and at changes in grade. (e) When plan applications, whether preliminary or final, are submitted in sections, a generalized stormwater management plan for the entire project site, in addition to the detailed stormwater management plan for the proposed section. This generalized plan shall demonstrate how the stormwater of the proposed section will relate to the entire development. The amount and velocity at the discharge point of the section shall be included in the data submitted. If temporary facilities are required for construction of a section, such facilities shall be included in the submitted plans. (f) A note on the plan indicating any area that is not to be offered for dedication, along with a statement that the township is not responsible for maintenance of any area not dedicated to and accepted for public use and that no alteration to swales or basins or placement of structures shall be permitted within easements. (g) A certificate, signed and sealed by an individual registered in the Commonwealth of Pennsylvania and qualified under all applicable local and state laws to perform such duties, indicating the compliance of the design of the stormwater management facilities with the provisions of this chapter. See Appendix (5) Erosion and sedimentation controls. The type, location and extent of all erosion and sedimentation control measures shall be shown on an erosion and sedimentation control plan that conforms to the requirements of Part IV of the Soil Erosion and Sedimentation Control Manual of the DEP. B. A written report, including the following information: 15. Editor s Note: Appendix No. 8 is located at the end of this chapter. 149:

37 STORMWATER MANAGEMENT (1) Stormwater runoff calculations for both predevelopment and postdevelopment conditions. (2) An erosion and sedimentation control plan narrative that conforms to the requirements of Part IV of the Soil Erosion and Sedimentation Control Manual of the DEP. (3) An ownership and maintenance program that clearly sets forth the ownership and maintenance responsibility of all temporary and permanent stormwater management facilities and erosion and sedimentation control facilities. (a) Said program shall include: [1] A description of temporary and permanent maintenance requirements. [2] The identification of a responsible individual, corporation, association or other entity for ownership and maintenance of both temporary and permanent stormwater management and erosion and sedimentation control facilities. [3] The establishment of suitable easements for access to all facilities. Drainage easements and access roads shall be required from detention/retention ponds to public roads when said ponds do not abut a public street. (b) The intent of these regulations is to provide private ownership and maintenance of stormwater management and erosion and sedimentation control facilities. Where the stormwater management plan proposes that the township own or maintain the facilities, a description of the methods, procedures and the extent to which any facilities shall be turned over to the township shall be incorporated as an integral part of the plan. C. Financial security for the completion of stormwater management facilities, as set forth in of this chapter. D. A maintenance guaranty, as set forth in this chapter. E. The filing fee and/or inspection fee in the amount specified on the Fee Schedule, as may be amended from time to time, adopted by resolution of the Board of Supervisors. 16 F. A DEP permit for any stormwater management facility requiring a permit to be issued by the DEP. G. A PADOT highway occupancy permit for any stormwater facility proposed within the right-of-way if a state road. 16. Editor s Note: The Fee Schedule is on file in the township offices. 149:

38 WEST EARL CODE Subdivisions and land developments. All stormwater management plans for subdivisions and land developments submitted under the jurisdiction of Chapter 155, Subdivision and Land Development, shall adhere to the procedures required by said chapter, including the number of copies of material to be submitted. Stormwater management plans for all other development shall adhere to the plan procedure delineated in of this chapter Other development activities. A. Four copies of the stormwater management plan, including all supporting information, and a filing fee shall be submitted to the Township Secretary. B. The Township Secretary shall submit a copy of the plan to the Township Planning Commission, the Township Engineer and the Lancaster County Conservation District for their respective reviews and recommendations. C. All applications for approval of a plan shall be acted upon by the Board of Supervisors, which shall render its decision and communicate it to the developer not later than 90 days following the date the application is filed. (1) The decision of the Board of Supervisors shall be in writing and shall be communicated to the developer personally or mailed to him at his last known address not later than 15 days following the decision. (2) When the application is not approved in terms as filed, the decision shall specify the defects found in the application and describe the requirements which have not been met and shall, in each case, cite the provisions of the chapter relied upon. (3) Failure of the Board of Supervisors to render a decision and communicate it to the developer within the time and in the manner required herein shall be deemed an approval of the application in terms as presented, unless the developer has agreed, in writing, to an extension of time or a change in the prescribed manner of presentation or communication of the decision, in which case failure to meet the extended time or a change in the manner of presentation of communication shall have like effect. D. Approval of a stormwater management plan by the township shall not be construed as an indication that the plan complies with the standards of any agency of the commonwealth. E. Approval of a storrnwater management plan by the township shall be obtained by a developer prior to the issuance of a zoning permit by the township. No construction of stormwater management facilities may begin until a zoning permit is obtained by the developer in accordance with Chapter 184, Zoning (Reserved) (Reserved) 149:

39 STORMWATER MANAGEMENT (Reserved) (Reserved) (Reserved) ARTICLE V Completion of Facilities or Guarantee Thereof Completion of facilities as part of a subdivision or land development. Stormwater management facilities shall be completely installed prior to final plan approval unless the developer submits proper financial security with the final plan application in accordance with Chapter 155, Subdivision and Land Development Determination of financial security. A. Where required, the developer shall file with the Board of Supervisors financial security in an amount sufficient to cover the costs of all stormwater management facilities required by this chapter. When requested by the developer, in order to facilitate financing, the Board of Supervisors or the Planning Commission, if designated, shall furnish the developer with a signed copy of a resolution indicating approval of the final stormwater management plat contingent upon the developer obtaining a satisfactory financial security. The final plat or record plan shall not be signed nor recorded until the financial improvements agreement is executed. The resolution or letter of contingent approval shall expire and be deemed to be revoked if the financial security agreement is not executed within 90 days, unless a written extension is granted by the Board of Supervisors; such extension shall not be unreasonably withheld and shall be placed in writing at the request of the developer. B. Without limitation as to other types of financial security which the township may approve, which approval shall not be unreasonably withheld, federal or commonwealth chartered lending institution irrevocable letters of credit and restrictive or escrow accounts in such lending institutions shall be deemed acceptable financial security. Such financial security shall be posted with a bonding company or federal or commonwealth chartered lending institution chosen by the developer, provided that said bonding company or lending institution is authorized to conduct such business within the commonwealth. Such bond or other security shall provide for and secure to the public completion of all stormwater management facilities within one year of the date fixed on the finally approved plan for the completion of such facilities. C. The amount of financial security to be posted for the completion of the improvements shall be equal to 110% of the cost of completion estimated as of 90 days following the date scheduled for completion by the developer. Annually, the township may adjust the amount of the financial security by comparing the actual cost of the improvements which have been completed and the estimated cost for the completion of the remaining 149:

40 WEST EARL CODE improvements as of the expiration of the 90th day after either the original date scheduled for completion or a rescheduled date of completion. Subsequent to said adjustment, the township may require the developer to post additional security in order to assure that the financial security equals said 110%. Any additional security shall be posted by the developer in accordance with this chapter. D. The amount of financial security required shall be based upon an estimate of the cost of completion of the required improvements, submitted by an applicant or developer and prepared by a professional engineer licensed as such in this commonwealth and certified by such engineer to be a fair and reasonable estimates of such cost. The township, upon the recommendation of the Township Engineer, may refuse to accept such estimate for good cause shown. If the applicant or developer and township are unable to agree upon an estimate, then the estimates shall be recalculated and recertified by another professional engineer licensed as such in this commonwealth and chosen mutually by the township and the applicant or developer. The estimate certified by the third engineer shall be presumed fair and reasonable and shall be the final estimate. In the event that a third engineer is so chosen, fees for the services of said engineer shall be paid equally by the township and the applicant or developer. E. If the developer requires more than one year from the date of posting of the financial security to complete the required improvements, the amount of financial security may be increased by an additional 10% for each one-year period beyond the first anniversary date from posting of financial security or to an amount not exceeding 110% of the cost of completing the required improvements as reestablished on or about the expiration of the preceding one-year period by using the above procedures. F. If financial security has been provided in lieu of the completion of improvements required as a condition for the final approval of a plat as set forth in the chapter, the township shall not condition the issuance of building, grading or other permits relating to the erection or placement of improvements, including buildings, upon the lots or land as depicted upon the final plat upon actual completion of the improvements depicted upon the approved final plat. Moreover, if said financial security has been provided, occupancy permits for any building or buildings to be erected shall not be withheld following the improvement of the streets providing access to and from existing public roads to such building or buildings to a permanently passable condition, as well as the completion of all other improvements as depicted upon the approved plat, either upon the lot or lots or beyond the lot or lots in question if such improvements are necessary for the reasonable use of or occupancy of the building or buildings Financial security for staged development. In the case where development is projected over a period of years, the Board of Supervisors may authorize submission of stormwater management plan applications by section or stages of development subject to such requirements or guarantees as to stormwater management facilities in future sections or stages of development as it finds essential for the protection of any finally approved section of the development. 149:

41 STORMWATER MANAGEMENT Release of financial security. As the work of installing the required stormwater management facilities proceeds, the developer may request the township to release or authorize the release, from time to time, such portions of the financial security necessary for payment to the contractor or contractors performing the work. Any such requests shall be in writing addressed to the township, which shall have 45 days from receipt of such request within which to allow the Township Engineer to certify, in writing, to the township that such portion of the work upon the facilities has been completed in accordance with the approved plan. Upon such certification, the township shall authorize release by the bonding company or lending institution of an amount as estimated by the Township Engineer fairly representing the value of the facilities completed or, if the township fails to act within said forty-five-day period, the township shall be deemed to have approved the release of funds as requested. The township may, prior to final release at the time of completion and certification by the Township Engineer, require retention of 10% of the estimated cost of the aforesaid facilities Schedule of inspections. A. During the construction of the development, the Township Engineer or other authorized township official may inspect the premises to determine that the work is progressing in compliance with the information provided on the approved stormwater management plan and with all applicable township laws and ordinances. B. The cost for the conducting of inspections by the Township Engineer or other authorized township official shall be borne by the developer in accordance with the inspection fee adopted by resolution of the Board of Supervisors. C. In the event that the Township Engineer or authorized official discovers that the work does not comply with the approved plan or any applicable laws and ordinances, the township shall suspend any existing zoning permits related to the development until the required corrections have been made. Any portion of the work which does not comply with the approved plan must be corrected by the developer within 10 days. No work may proceed on any subsequent phase of the stormwater management plan, the subdivision or land development or the building construction until the related zoning permits have been reinstated. D. if, at any stage of the work, the Township Engineer or authorized official determines that the soil or other conditions are not as stated or shown in the approved application or that there has been a false statement or misrepresentation by the developer, the Township Engineer or authorized official may refuse to approve further work, and the township may revoke existing zoning permits until a revised plan is submitted and approved, as required by of this chapter Final inspection. A. When the developer has completed all the required facilities, he shall notify the township, in writing, by certified or registered mail, and shall send a copy of such notice to the Township Engineer. The Board of Supervisors shall, within 10 days after receipt of 149:

42 WEST EARL CODE such notice, authorize the Township Engineer to inspect the required facilities. The Township Engineer shall promptly file a report, in writing, with the township and shall mail a copy of the report to the developer, by certified or registered mail. The report shall be made and mailed within 30 days after receipt by the Township Engineer of the aforesaid authorization by the township. B. Based on the report of the Township Engineer, the township shall indicate approval or rejection of the stormwater management facilities, either in whole or in part, and, if not approved, state reasons for the rejection. The township shall notify the developer within 15 days of receipt of the engineer s report, in writing, by certified or registered mail, of its actions. C. If the Board of Supervisors or the Township Engineer fails to comply with the time limitation provisions contained herein, all stormwater management facilities will be deemed to have been approved, and the developer shall be released from all liability, pursuant to its performance guarantee bond or other security agreement. D. If any portion of said improvements are not approved or are rejected by the township, the developer shall proceed to complete the same, and, upon completion, the same procedure of notification outlined herein shall be followed. E. The township may prescribe that the applicant shall reimburse the township for the reasonable and necessary expense incurred for the inspection of improvements. Such reimbursement shall be based upon a schedule established by ordinance or resolution. Such expense should be reasonable and in accordance with the ordinary and customary fees charged by the Township Engineer for the work performed for similar services in the community, but in no event shall the fees exceed the rate or cost charged by the engineer otherwise imposed on applicants. (1) In the event that the applicant disputes the amount of any such expense in connection with the inspection of improvements, the applicant shall, within 10 working days of the date of billing, notify the township that such expenses are disputed as unreasonable or unnecessary, in which case the township shall not delay or disapprove a subdivision or land development application or any approval or permit related to development due to the applicant s request over disputed engineer expenses. (2) If, within 20 days from the date of billing, the township and the applicant cannot agree on the amount of expenses which are reasonable and necessary, then the applicant and the township shall jointly, by mutual agreement, appoint another professional engineer licensed as such in the Commonwealth of Pennsylvania to review said expenses and make a determination as to the amount thereof which is reasonable and necessary. (3) The professional engineer so appointed shall hear such evidence and review such documentation as the professional engineer in his or her sole opinion deems necessary and render a decision within 50 days of the billing date. The applicant shall be required to pay the entire amount determined in the decision immediately. 149:

43 STORMWATER MANAGEMENT (4) In the event that the township and applicant cannot agree upon the professional engineer to be appointed within 20 days of the billing date, then, upon application of either party, the President Judge of the Court of Common Pleas of the judicial district in which the municipality is located (or, if at the time there be no President Judge, then the senior active judge then sitting) shall appoint such engineer, who, in that case, shall be neither the Township Engineer nor any professional engineer who has been retained by, or performed services for, the township or the applicant within the preceding five years. (5) The fee of the appointed professional engineer for determining the reasonable and necessary expenses shall be paid by the applicant if the amount of payment required in the decision is equal to or greater than the original bill. If the amount of payment required in the decision is less than the original bill by $1,000 or more, the township shall pay the fee of the professional engineer, but otherwise the township and the applicant shall each pay 1/2 of the fee of the appointed professional engineer Failure to install facilities. In the event that any stonnwater management facilities which may be required have not been installed as provided in this chapter or in accordance with the approved final plan, the Board of Supervisors has the power to enforce any corporate bond or other security by appropriate legal and equitable remedies. If proceeds of such bond or other security are insufficient to pay the cost of installing or making repairs or corrections to all the facilities covered by said security, the Board of Supervisors may, at its option, install part of such facilities in all or part of the development and may institute appropriate legal or equitable action to recover the moneys necessary to complete the remainder of the facilities. All of the proceeds, whether resulting from the security or from any legal or equitable action brought against the developer, or both, shall be used solely for the installation of the stormwater management facilities covered by such security and not for any other purpose (Reserved) (Reserved) (Reserved) ARTICLE VI Maintenance of Stormwater Management Facilities Maintenance of facilities during development. Maintenance of stormwater management facilities during development of a project site shall be the responsibility of the developer and the landowner and shall include but not he limited to: 149:

44 WEST EARL CODE A. Removal of silt from all debris basins, traps or other structures or measures when 60% of the capacity is filled with silt; provided, however, that in no case shall the sediment level be permitted to build up higher than one foot below the principal outlet crest. At this elevation, clean out shall be performed to restore the original design volume to the basin or other structure. The elevation corresponding to the maximum allowable sediment level shall be determined and stated in the design data as a distance below the top of the riser. The elevation shall be clearly marked on the riser to enable proper maintenance. B. Periodic maintenance of temporary control facilities, such as replacement of straw bale dikes, straw filters or similar measures. C. Establishment or reestablishment of vegetation by seeding and mulching or sodding of scoured areas or areas where vegetation has not successfully been established. D. Installation of necessary controls to correct unforeseen problems caused by storm events within design frequencies. E. Removal of all temporary storrnwater management control facilities upon installation of permanent stormwater management facilities at the completion of the development Maintenance of facilities after development. It is the purpose and intent of this chapter that the township shall not become responsible for maintenance and supervision of stormwater management facilities unless such facilities are within rights-of-way dedicated to and accepted by the township or unless such facilities are specifically accepted by the township. The plan shall reflect and/or be accompanied by supporting documentation identifying the ownership of and the responsibility to maintain all stormwater management facilities. The responsibility for stormwater management facility maintenance falls upon the developer of the project site who shall remain responsible for those areas of the project site which are subject to the requirements of this chapter. This responsibility may be retained or assigned to third persons as is deemed most acceptable to the developer. A. It is the intent of this chapter that the purposes of this chapter shall be carried out through the exercise of responsibility of private parties, and, therefore, it is anticipated that stormwater management plans shall be designed with a view towards facilities which can effectively be contained within the tracts to be owned and maintained by private parties. To foster this purpose, stormwater management facilities which will not otherwise become part of township property shall become the responsibility of the individual property owners on whose properties such stormwater management facilities lie, including but not limited to retention ponds, detention ponds, sediment basins, energy dissipators or grassed waterways, or may be maintained by a private entity. B. The township and the developer shall enter into an agreement, which shall be recorded, setting forth such maintenance responsibilities. Persons, including developers, conveying property within a project site to another party which contains any stormwater management facilities shall include a specific deed reference to such grantee s responsibility for the maintenance and care of the stormwater management facilities as are included within such grantee s property. The agreement shall impose responsibilities 149:

45 STORMWATER MANAGEMENT upon said property owner for the maintenance of the portions of the stormwater management facilities within the boundary lines of said property as may be necessary for proper maintenance of the stormwater management facilities in accordance with the terms of this chapter or it may impose such responsibilities upon a private entity in accordance with the requirements of this section and C. Required maintenance of stormwater management facilities shall include at a minimum the following: (1) Liming and fertilizing vegetated channels and other areas according to specifications in the Erosion and Sedimentation Control Handbook of Lancaster County. (2) Reestablishment of vegetation by seeding and mulching or sodding of scoured areas or areas where vegetation has not been successfully established. (3) Mowing as necessary to maintain adequate stands of grass and to control weeds. Chemical weed control may be used if state and local regulations are met. (4) Removal of silt from all permanent structures which trap silt or sediment in order to keep the material from building up in the grass waterways thus reducing their capacity. (5) Regular inspection of the areas in question to assure proper maintenance and care. (6) Removal of silt from all permanent drainage structures in order to maintain the design storage volumes. Regular maintenance programs shall be established and maintained. D. The agreement between the township and the developer hereinabove mentioned shall also include notice that in the event that the individual property owner or other responsible entity should fail to comply with the terms of this chapter for the maintenance and care of the land in question, the township shall have the authority to carry out those duties hereby imposed upon individual property owners or other responsible entity. The township may, after giving notice to an individual property owner or other responsible entity, as applicable, that he or it is not properly maintaining the areas subject to this chapter, and by making demand that such compliance shall be made within the time period set forth in the notification, enter upon said property and take such actions as may be required to bring the area into compliance with this chapter. The township shall further have the right to file a municipal lien against such property or, if a private entity is responsible for maintenance, to file a municipal lien as set forth in and Section 705 of the Pennsylvania Municipalities Planning Code ( MPC ) 17 to recover the cost of maintenance work carried out under this section, plus a penalty of 10% of the costs of such work. The township shall, in addition to the filing of a municipal lien, have any other remedies provided by law against any property owner or other entity who should fail to comply with the terms of this chapter. 17. Editor s Note: See 53 P.S et seq. 149:

46 WEST EARL CODE Maintenance of facilities accepted by township. A. Where the Board of Supervisors accepts dedication of all or some of the required stormwater management facilities following completion, the Board of Supervisors shall require the posting of financial security to secure the structural integrity of said facilities, as well as the functioning of said facilities, in accordance with the design and specifications as depicted on the approved stormwater management plan. The term of the financial security shall be 18 months from the date of acceptance of dedication, and the amount of financial security shall be 15% of the actual cost of installation of said improvements. B. The financial security shall be of the same type required in with regard to installation of stormwater management facilities Maintenance of facilities not accepted by township. A. Responsibility. (1) It is the intent of this chapter that the purposes of this chapter shall be carried out through the exercise of responsibility of private parties, and, therefore, it is anticipated that stormwater management plans shall be designed with a view towards facilities which can effectively be contained within the tracts to be owned and maintained by private parties. To foster this purpose, with respect to stormwater management facilities on a project site as shown on a plan of a developer, which stormwater management facilities will not otherwise become part of township property, such facilities shall become the responsibility of the individual property owners on whose properties such stormwater management facilities lie, including but not limited to retention ponds, detention ponds, sediment basins, energy dissipaters or grassed waterways, and the township and developer shall enter into an agreement, which shall be recorded, setting forth such maintenance responsibilities. (2) Persons, including developers, conveying property within a project site to another party, which property contains any stormwater management facilities, shall include a specific deed reference to such grantee s responsibility for the maintenance and care of the stormwater management facilities as are included within such grantee s property. The deed reference to such stormwater management facilities shall be in the form of a deed restriction imposing responsibilities upon said property owner for the maintenance of the portions of the stormwater management facilities within the boundary lines of said property as may be necessary for proper maintenance of the stormwater management facilities in accordance with the terms of this chapter. Such maintenance shall include, at a minimum, the following: (a) Liming and fertilizing vegetated channels and other areas according to specifications in the Erosion and Sedimentation Control Handbook of Lancaster County. 149:

47 STORMWATER MANAGEMENT (b) Reestablishment of vegetation by seeding and mulching or sodding of scoured areas or areas where vegetation has not been successfully established. (c) Mowing as necessary to maintain adequate strands of grass and to control weeds. Chemical weed control may be used if state and local regulations are met. (d) (e) (f) (g) Removal of silt from all permanent structures which trap silt or sediment in order to keep the material from building up in the grass waterways, thus reducing their capacity. Regular inspection of the areas in question to assure proper maintenance and care. Removal of silt from all permanent drainage structures in order to maintain the design storage volumes. Replacement of pipes and structures, if deemed necessary by the township. B. The deed restrictions hereinabove mentioned shall also include notice that, in the event that the individual property owner should fail to comply with the terms of this chapter for the maintenance and care of the land in question, the township shall have the authority to carry out those duties hereby imposed upon individual property owners. The township may, after giving notice to an individual property owner that he is not properly maintaining the areas subject to this chapter and by making a demand that such compliance shall be made within the time period set forth in the notification, enter upon said property and take such actions as may be required to bring the area into compliance with this chapter. The township shall further have the right to file a municipal lien against such property for the cost of maintenance work carried out under this section, plus a penalty of 10% of the costs of such work. The township shall, in addition to the filing of a municipal lien, have any other remedies provided by law against any property owner who should fail to comply with the terms of this chapter Maintenance of facilities by private entity. In cases where permanent maintenance of stormwater management facilities is to be performed by a private entity, such as a homeowners association or a condominium unit owners association, such entity shall be responsible for the maintenance of such facilities and shall enter into a legally binding agreement with the township. Such agreement shall provide the township rights, in accordance with 705 of the Pennsylvania Municipalities Planning Code, 18 relating to the maintenance of common open space should the private entity fail to adequately maintain the stormwater management facilities. 18. Editor s Note: See 53 P.S et seq. 149:

48 WEST EARL CODE Maintenance of existing facilities. Stormwater management facilities existing on the effective date of this chapter on individual lots which have not been accepted by the township or for which maintenance responsibility has not been assumed by a private entity such as a homeowners association shall be maintained by the individual property owners. Such maintenance shall include at a minimum those items set forth in l49-54a above. If the township determines at any time that any permanent stormwater management facility has been eliminated, altered, blocked through the erection of structures or the deposit of materials or improperly maintained, the township may determine that such condition constitutes a nuisance and shall notify the property owner of corrective measures which are required and provide for a reasonable period of time, not to exceed 30 days, within which the property owner shall take such corrective action. If the property owner does not take the required corrective action, the township may either perform the work or contract for the performance of the work and bill the property owner for the cost of the work, plus a penalty of 10% of the cost of the work. If such bill is not paid by the property owner within 30 days, the township may file a municipal claim agianst the property upon which the work was performed in accordance with applicable laws Alteration of facilities. No person shall modify, remove, fill, landscape or alter stormwatcr management facilities which may have been installed on a property unless a stormwater management plan has been approved which authorizes such modification, removal, filling, landscaping or alteration. No person shall place any structure, fill, landscaping or vegetation into a stormwater management facility or within a drainage easement which will limit or alter the functioning of the facility or easement in any manner Prohibited discharges. [Added by Ord. No. 1791] A. No person in the Township shall allow or cause to allow stormwater discharges into the Township s separate storm sewer system which are not composed entirely of stormwater, except discharges allowed under a state or federal permit. B. The Township may allow discharges under the Township s NPDES permit based on a finding by the Township that the discharge(s) do not significantly contribute to pollution to surface waters of the commonwealth. The Township may allow the following discharges: [Amended by Ord. No. 191] (1) Discharges from fire-fighting activities. (2) Potable water sources including dechlorinated water line and fire hydrant flushing. (3) Irrigation drainage. (4) Routine external building wash down which does not use detergents or other compounds. (5) Air conditioning condensate. (6) Water from individual residential car washing. 149:

49 STORM WATER MANAGEMENT (7) Springs. (8) Water from crawl space pumps. (9) Uncontaminated water from foundations or floor drains. (10) Flows from riparian habitats and wetlands. (11) Lawn watering. (12) Pavement wash waters where spills or leaks of toxic or hazardous materials have not occurred (unless all spill material has been removed) and where detergents are not used. (13) Dechlorinated swimming pool discharges. (14) Uncontaminated groundwater. C. In the event that the Township subsequently determines that any of the discharges identified in B significantly contribute to pollution of waters of the commonwealth, the Township will notify the responsible person to cease the discharge. D. Upon notice provided by the Township under l49-58c, the discharger will have a reasonable time to cease the discharge consistent with time degree of pollution caused by the discharge Prohibited connections. [Added by Ord. No. 179] A. The following connections to the Township storm sewers or stormwater drainage systems are prohibited: (I) Any drain or conveyance, whether on the surface or subsurface, which allows any nonstormwater discharge including sewage, process wastewater, and washwater to enter the separate storm sewer system, and any connections to the storm drain system from indoor drains and sinks; and (2) Any drain or conveyance from a commercial or industrial land use to the separate storm sewer system which has not been documented in plans, maps, or equivalent records, and approved by the Township. B. This prohibition expressly includes, without limitation, connections made in the past, regardless of whether the connection, drain or conveyance was previously allowed, permitted, or approved by a government agency, or otherwise permissible under law or practices applicable or prevailing at the time of connection Roof drains. [Added by Ord. No. 179] A. Roof drains shall not be connected to streets, sanitary or storm sewers or roadside ditches, except as provided in B. 149:

50 WEST EARL CODE B. When it is more advantageous to connect directly to streets or storm sewers, connections of roof drains to streets or roadside ditches may be permitted on a case-by-case basis by the Township. It shall be the burden of the person seeking to make the connection to demonstrate to the Township that such connection is more advantageous and such connection shall not violate any state or federal statute, rule or regulation. C. Roof drains shall discharge to infiltration areas or vegetative BMPs to the maximum extent possible Waste disposal prohibitions. [Added by Ord. No. 179] No person shall throw, deposit, leave, maintain, keep, or permit to be thrown, deposited, left, or maintained in or upon any public or private property, driveway, parking area, street, alley, sidewalk, or other component of the Township s separate storm sewer system, any refuse, rubbish, garbage, litter, or other discarded or abandoned objects, articles, and accumulations, so that the same may cause or contribute to pollution. Wastes deposited in streets in proper waste receptacles for the purposes of collection are exempted from this prohibition Right of entry. ARTICLE VII Administration and Enforcement Upon presentation of proper credentials, duly authorized representatives of the township may enter at reasonable times upon any property within the township to investigate or ascertain the condition of the subject property in regard to any aspect regulated by this chapter Revisions or alterations of stormwater management facilities. Any revision or alteration to stormwater management control methods or facilities as previously installed or as proposed by an approved plan shall require the developer to submit a revised plan in accordance with the requirements in Article IV of this chapter Waivers or modifications of standards. A. The provisions of this chapter are intended as minimum standards for the protection of the public health, safety and welfare. The Board of Supervisors may grant a waiver from literal compliance with mandatory provisions of this chapter or a modification of the standards of this chapter if the applicant can demonstrate either that compliance would cause undue hardship as it applies to a particular property or that an alternative proposal will allow for equal or better results. 149:

51 STORMWATER MANAGEMENT B. The approval of the waiver or modification shall not have the effect of making null and void the intent and purpose of the chapter. In the approval of a waiver or modification, the Board of Supervisors may impose such conditions as will, in its judgment, secure substantially the objectives of the standards and requirements of this chapter. C. All requests for waivers or appeals shall be processed in accordance with the following: (1) A request for a waiver or appeal shall be submitted at the Township Municipal Building on any business day. The request shall be made in writing and identify the specific section of this chapter which is requested to be waived or modified, the proposed alternative to the requirement, when applicable, and justifications for an approval of the waiver or modification. (2) The township staff shall schedule the request for consideration by the Board of Supervisors at a public meeting within 60 days of receipt and provide adequate notice to the applicant and any other involved parties of the meeting at which consideration of the request is scheduled. (3) The Board of Supervisors shall, following the consideration of the request, take such public action as it shall deem advisable and notify all involved parties within 20 days of the action. Such notice shall cite the findings and reasons for the deposition of the waiver application. D. Any person aggrieved by the action of the Board of Supervisors concerning an application for a waiver or modification of the standards of this chapter may file an appeal to the Lancaster County Court of Common Pleas in accordance with the provisions of the Local Agency Law, 2 Pa. C.S.A. 751 et seq Violations. It shall be a violation of this chapter to commit or permit any other person to commit any of the following acts: A. To commence land disturbance activities for which this chapter requires a permit prior to obtaining a permit or in violation of the terms or conditions of any permit issued under this chapter. B. To install, repair, modify or alter stormwater management facilities prior to obtaining a permit under this chapter or in a manner which violates the terms and conditions of any permit issued under this chapter. C. To misuse or fail to maintain any stormwater management facility installed upon a property. D. To construct any improvements upon, grade, fill or take any other action which will impair the proper functioning of any stormwater management facility. E. To place false information on or omit relevant information from an application for a waiver, approval or permit under this chapter. F. To fail to comply with any other provisions of this chapter. 149:

52 WEST EARL CODE Penalties and remedies. A. If the Board of Supervisors or the officer designated to enforce this chapter by the Board of Supervisors determines that a person has committed or permitted the commission of a violation of this chapter, the Board of Supervisors or such enforcement officer shall inform such person, in writing, of the violation, shall notify such person to cease the violation of this chapter and shall inform such person that he or she must pay a civil penalty to the township within the range of the amounts set forth below to settle the violation. The penalty for a first offense shall be not less than $50 and not more than $600; the penalty for a second offense shall be not less than $100 and not more than $600; and the penalty for a third or greater offense shall be not less than $200 and not more than $600. If such person fails or refuses to remit the penalty to the township within 10 days from the date of the written notice of the violation of this chapter, the township may commence a civil enforcement proceeding seeking penalties and costs for the violation of this chapter and/or may commence an action in equity. The township shall seek a judgment for the penalty previously imposed together with additional daily penalties for continuing violations, plus all court costs, including the reasonable attorneys fees incurred by the township in the enforcement proceedings. Each day that a violation continues shall constitute a separate violation, and each section of this chapter which is violated shall constitute a separate violation. If the defendant neither pays nor timely appeals the judgment, the township may enforce the judgment pursuant to the applicable rules of civil procedure. B. The township may institute suits in equity to restrain, prevent or abate any violation of this chapter. The township, if required to abate nuisance conditions, shall be entitled to recover its expenses from any financial security posted by a developer by filing a municipal claim against the property in the amount of the cost of the abatement plus a penalty of 25% of such costs, or by any other means authorized by law. C. If an applicant for approval of a stormwater management plan has presented any incorrect information in connection with the review or approval of the plan, the Board of Supervisors may revoke approval of the stormwater management plan. When a plan approval has been revoked, it shall not be reinstated. The applicant shall be required to submit a new stormwater management plan application in accordance with the processing procedures in this chapter Appeals. Any person aggrieved by an administrative decision of the Board of Supervisors may file an appeal to the Lancaster County Court of Common Pleas in accordance with the provisions of the Local Agency Law, 2 Pa. C.S.A. 751 et seq Repealer. Ordinance No. 41 of the Township of West Earl, as amended, is expressly repealed; provided, however, that the provisions of Ordinance No. 41 and all amendments thereto shall be applied to all subdivision and land development applications and plans to which such requirements are applicable under the provisions of Section 508(4) of the Pennsylvania Municipalities Planning 149:

53 STORMWATER MANAGEMENT Code ( MPC ), Act of July 31, 1968, P.L. 805, No. 247, as amended and reenacted, 53 P.s (4). All ordinances and parts of ordinances and all resolutions and parts of resolutions which are inconsistent herewith by virtue of references to or incorporation of the requirements of Ordinance No. 41 or an amendment thereto shall, as nearly as possible, be construed to reference this chapter. 149:

54

55

56

57

58