This chapter shall be known and may be cited as the "Township of Haverford Erosion and Sediment Control Ordinance."
[HISTORY: Adopted by the Board of Commissioners of the Township of Haverford 11-12-2024 by Ord. No. 3000-2024[1]. Amendments noted where applicable.]
Attachment 1 - Table 105.1 Applicability
Attachment 2 - Appendix A Watershed MapAttachment 3 - Appendix BAttachment 4 - Appendix C-1 Drainage Plan ApplicationAttachment 5 - Appendix C-2 Drainage Plan ChecklistAttachment 6 - Appendix D Darby and Cobbs Creek WatershedAttachment 7 - Appendix E LID PracticesAttachment 8 - Appendix F Design CriteriaAttachment 9 - Appendix G West Nile Virus GuidanceAttachment 10 - Appendix H ReferencesAttachment 11 - Appendix I Stormwater Controls and Best ManagementAttachment 12 - Riparian Buffer Trail GuidelinesAttachment 13 - Figure J-1
Attachment 2 - Appendix A Watershed MapAttachment 3 - Appendix BAttachment 4 - Appendix C-1 Drainage Plan ApplicationAttachment 5 - Appendix C-2 Drainage Plan ChecklistAttachment 6 - Appendix D Darby and Cobbs Creek WatershedAttachment 7 - Appendix E LID PracticesAttachment 8 - Appendix F Design CriteriaAttachment 9 - Appendix G West Nile Virus GuidanceAttachment 10 - Appendix H ReferencesAttachment 11 - Appendix I Stormwater Controls and Best ManagementAttachment 12 - Riparian Buffer Trail GuidelinesAttachment 13 - Figure J-1A.
The purpose of this chapter is to regulate the modification of the natural terrain, the alteration of drainage, the maintenance of artificial structures and surfaces and to provide for certain erosion and sediment control measures within the Township of Haverford so as to assure and safeguard health, safety, ecology and general welfare in the Township of Haverford.
B.
Scope of provisions. New grading, excavations and fills or changes, additions, repairs or alterations made to existing excavations and fills shall conform to the provisions of this chapter, except that this chapter shall not apply to work performed by the Township in a public street or on public property.
A.
A grading permit will not be required in the following situation, but in all other respects the provisions of this chapter shall apply:
B.
An excavation which does not exceed three feet in vertical depth at its deepest point measured from the natural ground surface nor cover an area of more than 200 square feet. This exception shall not affect the applicability of this chapter nor the requirement of a grading permit for any fill or grading made with the material from such excavation.
A.
It shall be unlawful for any person, firm or corporation to pave, fill, strip, grade or regrade any land within the Township of Haverford without first securing a permit as hereunder provided, except as otherwise stated in § 78-3.
B.
It shall be unlawful for any person, firm or corporation to disturb, modify, block, divert or affect the natural overland or subsurface flow of stormwater within the Township of Haverford without first securing a permit as hereunder provided.
C.
It shall be unlawful for any person, firm or corporation to construct, erect or install any drainage dam, ditch, culvert, drainpipe, bridge or any other structure or obstruction affecting the drainage of any premises in the Township of Haverford without first securing a permit as hereunder provided.
A.
Any person, firm or corporation proposing to engage in an activity requiring a permit hereunder shall apply for a permit by written application on a form furnished by the Township of Haverford.
B.
A separate application shall be required for each grading permit. Two hard copies and one digital copy of the proposed plan, including specifications and timing schedules, shall be submitted with each application for a permit.
C.
Applications for review required under this chapter shall be accompanied by a review fee as fixed by resolution of the Board of Commissioners, which may be amended from time to time.
D.
All applications for a permit involving an area of disturbance greater than 500 square feet shall be accompanied by a escrow deposit, to the benefit of the Township of Haverford in an amount as provided by Township resolution.
The application for a permit shall be accompanied by a plan of the property showing:
A.
A boundary line survey of the site on which the work is to be performed, showing the existing and proposed contours of the land and the proposed contours after completion of proposed grading.
B.
A description of the features, existing and proposed, surrounding the site which are of importance to the proposed development, including the nature of fill material and trees to be removed as a result of the proposed construction.
C.
Description of the type and classification of the soil.
D.
Details and location of any proposed drainage structures and pipes.
E.
The lowest floor elevation of any proposed building based upon North American Vertical Datum of 1988 and the elevation of the 100-year flood.
F.
The location and description of existing and future manmade features of importance to the proposed development, i.e., cuts and fills, buildings, roads, etc.
G.
Plans and specifications of soil erosion and sediment control measures in accordance with standards and specifications of the Delaware County Conservation District or the Township of Haverford.
H.
A time schedule indicating the anticipated starting and completion dates of the development sequence and the time of exposure of each area prior to the completion of effective erosion and sediment control measures.
I.
All plans and specifications accompanying applications for permits shall include provisions for both interim (temporary) and ultimate (permanent) erosion and sediment control.
(1)
The design, installation and maintenance of erosion and sediment control measures shall be accomplished in accordance with standards and specifications established by the Delaware County Conservation District as adapted from standards and specifications of the Soil Conservation Service, United States Department of Agriculture.
(2)
Technical standards for the design and installation of erosion and sediment control measures are on file with the Township of Haverford office, the office of the Delaware, County Conservation District and other governmental agency offices.
(3)
Standards and specifications adopted for the purposes of this chapter and by the Delaware County Conservation District include but are not limited to the following basic conservation measures:
(a)
Temporary cover on critical areas.
(b)
Permanent grass and cover on critical areas on prepared seedbed.
(c)
Permanent grass and cover on critical areas on unprepared seedbed.
(d)
Sodding.
(e)
Mulching.
(f)
Temporary diversion.
(g)
Permanent diversion.
(h)
Grassed waterway or outlet.
(i)
Grade stabilization structure.
(j)
Debris basin.
(k)
Drain.
(l)
Drainage, main or lateral.
A.
Stormwater management plans shall be as required in this chapter.
(1)
The application for a permit shall be accompanied by a plan of the property showing the location of all present and proposed ditches, streams, pipes and other drainage structures and proposed cuts and fills. In addition to showing present elevations and dimensions and location and extent of all proposed grading and/or drainage, the plan shall clearly indicate all buildings, parking areas and driveways. Further, the plan shall indicate the present and proposed sources, storage and disposition of water being channeled through or across the premises, together with elevations, gradients and maximum flow rates. The application shall describe the work to be performed, the materials to be used and the manner or method of performance, including provisions for protecting and maintaining existing drainage facilities whether on public or private property. The applicant shall supply data supporting the plan developed by a registered professional civil engineer or an engineer qualified in hydrology.
(2)
Stormwater management plans shall be prepared in accordance with this chapter.
B.
The following provisions apply to the carrying and disposal of stormwater runoff:
(1)
The applicant shall agree to the granting and recording of easements for drainage facilities, including acceptance of the discharge of water on the property of others, provisions for maintenance of slopes and swales and access for the maintenance of anti-erosion facilities.
C.
If load-bearing fill is proposed, a soils investigation report shall be submitted, which shall consist of test borings, laboratory testings and engineering analysis to correlate surface and subsurface conditions with the proposed grading plan. The results of the investigation shall be presented in a report by a registered professional soils engineer or geologist, which shall include data regarding the nature, distribution and supporting ability of existing soils and rocks on the site, conclusions and recommendations to ensure stable soil conditions and groundwater control, as applicable. The Township of Haverford may require such supplemental reports and data as it deems necessary. Recommendations included in such reports and approved by the Township of Haverford shall be incorporated in the plan or specifications.
(1)
Fills toeing out on natural slopes steeper than four horizontal to one vertical shall not be made unless approved by the Township of Haverford after receipt of a report, deemed acceptable by the Township of Haverford Engineer, by a registered professional soils engineer certifying that he has investigated the property, made soil tests and that, in his opinion, such steeper slopes will safely support the proposed fill.
(2)
Natural and/or existing slopes exceeding five horizontal to one vertical shall be benched or continuously stepped into competent materials prior to placing all classes of fill.
Upon the submission of an application which conforms to the provisions of this chapter, the Director of Code Enforcement or their designee, after consultation with the Township of Haverford Engineer, shall issue the necessary permit.
A.
Notwithstanding any provision of this chapter or any condition of the permit, the permittee is responsible for the prevention of damage to other property or personal injury which may be affected by the activity requiring a permit.
B.
No person, firm or corporation shall modify, fill, excavate, pave, grade or regrade land in any manner so close to a property line as to endanger or damage any adjoining street, sidewalk, alley or any other public or private property without supporting and protecting such property from settling, cracking, erosion, sediment or other physical damage or personal injury which might result.
C.
No person, firm or corporation shall deposit or place any debris or any other material whatsoever or to cause such to be thrown or placed in any drainage ditch or drainage structure in such a manner as to obstruct free flow.
D.
No person, firm or corporation shall fail to adequately maintain in good operating order any drainage facility on his premises. All drainage ditches, culverts, drainpipes and drainage structures shall be kept open and free-flowing at all times.
E.
The owner of any property on which any work has been done pursuant to a permit granted under this chapter shall continuously maintain and repair all graded surfaces and antierosion devices, retaining walls, drainage structures or means and other protective devices, plantings and ground cover installed or completed.
F.
All graded surfaces shall be seeded, sodded and/or planted or otherwise protected from erosion within 60 days and shall be watered, tended and/or maintained until growth, in the case of vegetation, is well established. The disturbed area and duration of exposure shall be kept to a practical minimum.
G.
All trees in the area of extreme grade change shall be removed unless protected with suitable tree wells. However, extreme precautions shall be taken to prevent the unnecessary removal of trees.
H.
When required, adequate provisions shall be made for dust control measures as are deemed acceptable by the Township of Haverford.
I.
A quality control program is critical for fills, therefore, whenever fill material is to be used, each layer of compacted fill should be tested to determine its dry density as per ASTM D 1556. The density of each layer should not be less than 95% of maximum dry density as determined by ASTM D 1557.
A.
The Township Engineer shall, when requested by the Director of Code Enforcement or their designee, make inspections hereinafter required and shall either approve that portion of the work which has been completed or notify the permit holder wherein the same fails to comply with the provisions of this chapter. Where it is found by inspection that the conditions are not as stated or shown in the application, the Township Engineer may refuse to approve further work until approval is obtained for a revised grading plan.
B.
Plans for the grading work shall be approved by the Township Engineer and shall be maintained at the site during the progress of the grading work and until the work has been approved.
C.
The permit holder shall notify the Township Engineer in order to obtain inspections, in accordance with the following schedule, at least 48 hours before the inspection is to be made:
(1)
Initial inspection. When work on the excavation or fill is about to be commenced.
(2)
Rough grading. When all rough grading has been completed.
(3)
Drainage facilities. When drainage facilities are to be installed and before such facilities are backfilled.
(4)
Special structures. When excavations are complete for retaining and crib walls, and when reinforcing steel is in place and before concrete is poured.
(5)
Final inspection. When all work, including the installation of all drainage and other structures, has been completed.
D.
If at any of the work the Township Engineer shall determine by inspection that the nature of the grading is not in accordance with the approved permit or is not functioning as designed and/or is likely to endanger property or streets or alleys or create hazardous conditions, the Township Engineer may require, as a condition to allowing the work to be done, that such reasonable safety precautions be taken as the Township Engineer considers advisable to avoid such likelihood of danger. Safety precautions may include but shall not be limited specifying a flatter exposed slope, construction or additional drainage facilities, berms, terracing, compaction or cribbing.
E.
Any and all as-built plans shall be available on the site at all times and be subject to inspection and inquiry.
F.
Satisfactory compliance with this chapter shall be necessary before issuance of an occupancy permit.
All applicants shall bear all cost of inspections required hereunder and shall deposit with the Director of Finance such sum as the Director of Code Enforcement shall determine to be necessary to guarantee payment of the cost of such inspections.
Any person, firm or corporation violating any provision of this article shall, upon summary conviction before any District Justice of the Peace, pay a fine not exceeding $1,000 and costs of prosecution; and in default of one payment of the fine and costs, the violator may be sentenced to the county jail for a term of not more than 90 days. Each and every day in which any person, firm or corporation shall be in violation of this article shall constitute a separate offense.
This article shall be known and may be cited as the "Township of Haverford Stormwater Management Ordinance."
The Board of Commissioners of Haverford Township finds that:
A.
Inadequate management of accelerated runoff of stormwater resulting from development throughout a watershed increases runoff volumes, flows and velocities, contributes to erosion and sedimentation, overtaxes the carrying capacity of streams and storm sewers, greatly increases the cost of public facilities to carry and control stormwater, undermines flood plain management and flood control efforts in upstream and downstream communities, infiltration, threatens public health and safety, and increases nonpoint source pollution of water resources.
B.
Inadequate planning and management of stormwater runoff resulting from land development throughout a watershed can also harm surface water resources by changing the natural hydrologic patterns, accelerating stream flows (which increase scour and erosion of streambeds and streambanks, thereby elevating sedimentation), destroying aquatic habitat, and elevating aquatic pollutant concentrations and loadings such as sediments, nutrients, heavy metals, and pathogens. Groundwater resources are also impacted through loss of recharge.
C.
A comprehensive program of stormwater management (SWM), including minimization of impacts of development, redevelopment, and activities causing accelerated runoff, is fundamental to the public health, safety, and welfare and the protection of people of the commonwealth, their resources, and the environment.
D.
Stormwater is an important water resource by providing infiltration for water supplies and supports the base flow of streams, which also protects and maintains surface water quality.
E.
Impacts from stormwater runoff can be minimized by using project designs that maintain the natural hydrologic regime and sustain high water quality, infiltration, stream baseflow, and aquatic ecosystems. The most cost-effective and environmentally advantageous way to manage stormwater runoff is through nonstructural project design that minimizes impervious surfaces and sprawl, avoids sensitive areas (i.e., stream buffers, floodplains, steep slopes), and considers topography and soils to maintain the natural hydrologic regime.
F.
Public education on the control of pollution from stormwater is an essential component in successfully addressing stormwater.
G.
Federal and state regulations require certain municipalities to implement a program of stormwater controls. These municipalities are required to obtain a permit for stormwater discharges from their separate storm sewer systems under the National Pollutant Discharge Elimination System (NPDES) program.
H.
Nonstormwater discharges to municipal separate storm sewer systems can contribute to pollution of waters of the commonwealth by Haverford Township.
I.
The use of green infrastructure and low-impact development (LID) are intended to address the root cause of water quality impairment by using systems and practices which use or mimic natural processes to: 1) infiltrate and recharge, 2) evapotranspire, and/or 3) harvest and use precipitation near where it falls to earth. Green infrastructure practices, LID, and cluster development (CD) contribute to the restoration or maintenance of predevelopment hydrology.
The purpose of this article is to promote the public health, safety, and general welfare, property, and water quality by implementing drainage and stormwater management practices, criteria, and provisions included herein for land development, construction, and earth disturbance activities, to achieve the following throughout the Township:
A.
Promote alternative project designs and layouts that minimize the impacts on surface and groundwater.
B.
Promote nonstructural best management practices (BMPs).
C.
Minimize increases in runoff stormwater volume.
D.
Minimize impervious surfaces.
E.
Manage accelerated stormwater runoff and erosion and sedimentation problems and stormwater runoff impacts at their source by regulating activities that cause these problems.
F.
Provide review procedures and performance standards for stormwater planning and management.
G.
Utilize and preserve existing natural drainage systems as much as possible.
H.
Manage stormwater impacts close to the runoff source, requiring a minimum of structures and relying on natural processes.
I.
Focus on infiltration of stormwater to maintain base flow, to prevent degradation of surface and groundwater quality, and to otherwise protect water resources.
J.
Protect base flows and quality of streams and watercourses, where possible.
K.
Meet legal water quality requirements under state law, including regulations at 25 Pennsylvania Code Chapter 93 to protect, maintain, reclaim, and restore the existing and designated uses of the waters of the commonwealth.
L.
Address the quality and quantity of stormwater discharges from the development site.
M.
Provide standards to meet certain NPDES MS4 permit requirements.
N.
Implement an illicit discharge detection and elimination program that addresses nonstormwater discharges into the municipality's separate storm sewer system (MS4).
O.
Preserve the flood-carrying capacity of streams.
P.
Protect water quality by removing and/or treating pollutants prior to discharge to ground- and surface waters throughout Haverford Township, and to protect, restore, and maintain the chemical, physical, and biological quality of ground and surface waters.
Q.
Reduce flooding impacts and prevent a significant increase in surface runoff rates and volumes, predevelopment to post-development, which could worsen flooding downstream in the watershed, enlarge floodplains, erode stream banks, and create other flood-related health, welfare or property losses; in general, to preserve and restore the natural flood-carrying capacity of streams and their floodplains.
R.
Prevent accelerated scour, erosion and sedimentation of stream channels.
S.
Provide performance standards and design criteria based on watershed-wide stormwater management planning.
T.
Provide proper operation and maintenance of all permanent stormwater management facilities and BMPs that are implemented within the Township.
U.
Implement the requirements of total maximum daily loads (TMDLs) where applicable to waters within or impacted by the Township.
The Township is empowered or required to regulate land use activities that affect runoff and surface and groundwater quality and quantity by the authority of:
A.
Act of October 4, 1978, 32 P.S., P.L. 864 (Act 167) § 680.1 et seq., as amended, the "Stormwater Management Act" (hereinafter referred to as "the Act");
B.
Water Resources Management Act of 2002, as amended;
C.
First Class Township Code, 53, Section 55101 et seq;
D.
Act of July 31, 1968, P.L. 805, No. 247, Pennsylvania Municipalities Planning Code, Act 247, as amended.
All regulated activities and all activities that may affect stormwater runoff, including but not limited to land development, redevelopment, and earth disturbance activity located within the municipality, are subject to regulation by this article.
A.
This article shall apply to all areas of Haverford Township.
B.
This article shall only apply to permanent structural and nonstructural stormwater management BMPs constructed as part of any of the regulated activities listed in this section.
C.
This article contains only the stormwater management performance standards and design criteria that are necessary or desirable from a watershed-wide perspective. Local stormwater management design criteria (e.g., inlet spacing, inlet type, collection system design and details, outlet structure design, etc.) shall continue to be regulated by the applicable municipal ordinances and applicable state regulations.
D.
The following activities are defined as "regulated activities" and shall be regulated by this article unless exempted by § 78-18:
(1)
Land development.
(2)
Subdivisions.
(3)
Alteration of the natural hydrologic regime.
(4)
Construction or reconstruction of or addition of new impervious surfaces (i.e., driveways, parking lots, roads, etc.).
(5)
Construction of new buildings or additions to existing buildings.
(6)
Redevelopment.
(7)
Diversion piping or encroachments in any natural or man-made channel.
(8)
Nonstructural and structural stormwater management BMPs or appurtenances thereto.
(9)
Earth disturbance activities of greater than 5,000 square feet.
(10)
Earth disturbances within 50 feet of other sensitive environmental features, such as streams, ponds, lakes and wetlands.
(11)
Any of the above regulated activities which were approved more than five years prior to the effective date of this article and resubmitted for municipal approval.
E.
Table 105.1 summarizes the applicability requirements of the ordinance. "Regulated impervious surface" in Table 105.1 includes new, additional, or replacement impervious surface/cover. Repaving existing surfaces without reconstruction does not constitute "replacement."
Exemptions for land use activities. An exemption shall not relieve the applicant from implementing the requirements of the municipal ordinance or from implementing such measures as are necessary to protect public health, safety, and property. An exemption shall not relieve the applicant from complying with the special requirements for watersheds draining to identified high quality (HQ) or exceptional value (EV) waters or any other current or future state or municipal water quality protection requirements. If a drainage problem is documented or known to exist downstream of, or is expected from the proposed activity, then the Municipality may withdraw exemptions listed in Table 105.1 and require the applicant to comply with all requirements of this article. Even though the applicant is exempt, he is not relieved from complying with other municipal ordinances or regulations.
Table 105.1 summarizes the exemptions from certain provisions of this article. Exemptions are for the items noted in Table 105.1 only, and shall not relieve the applicant from other applicable sections of this article.
Any regulated activity that is exempt from some provisions of the ordinance is exempt only from those provisions. If development is to take place in phases, the developer is responsible for implementing the requirements of the ordinance as the impervious surface/earth disturbance threshold is met. The date of the municipal ordinance adoption shall be the starting point from which to consider tracts as "parent tracts" in which future subdivisions and respective impervious area and earth disturbance computations shall be cumulatively considered. Exemption shall not relieve the applicant from implementing such measures as are necessary to protect health, safety, and property. For example:
If a property owner proposed a 150-square-foot shed after adoption of the municipal stormwater management ordinance, that property owner be exempted from the water quality and quantity requirements of the ordinance as noted in Table 105.1 of the ordinance. If, at a later date, the property owner proposes to construct a 499-square-foot room addition, the applicant would be required to comply with the requirements for the Simplified Method for the full 649 square feet of impervious surface created since adoption of the municipal ordinance. If an additional 700-square-foot swimming pool/patio is proposed later, the property owner would be required implement the full stormwater quantity and quality control submission requirements of this article for the total 1,349 square feet of additional impervious surface added to the original property since adoption of the municipal ordinance.
A.
Exemptions for land use activities. The following land use activities are exempt from the SWM site plan submission requirements of this article:
(1)
Use of land for gardening for home consumption.
(2)
Agriculture when operated in accordance with a conservation plan, nutrient management plan, or erosion and sedimentation control plan approved by the County Conservation District, including activities such as growing crops, rotating crops, tilling of soil, and grazing animals. Installation of new or expansion of existing farmsteads, animal housing, waste storage, and production areas having impervious surfaces that result in a net increase in earth disturbance of greater than 5,000 square feet shall be subject to the provisions of this article.
(3)
High tunnel if:
(a)
The high tunnel or its flooring does not result in an impervious surface exceeding 25% of all structures located on the Landowner's total contiguous land area; and
(b)
The high tunnel meets one of the following:
[1]
The high tunnel is located at least 100 feet from any perennial stream or watercourse, public road, or neighboring property line.
[2]
The high tunnel is located at least 35 feet from any perennial stream or watercourse, public road or neighboring property line and located on land with a slope not greater than 7%.
[3]
The high tunnel is supported with a buffer or diversion system that does not directly drain into a stream or other watercourse by managing stormwater runoff in a manner consistent with the requirements of Pennsylvania Act 167.
(4)
Forest management operations which are following the Department of Environmental Protection's (DEP) management practices contained in its publication "Soil Erosion and Sedimentation Control Guidelines for Forestry" and are operating under an approved erosion and sedimentation plan and must comply with the stream buffer requirements in § 78-42.
(5)
Road replacement, development, or redevelopment that has less than 500 square feet of new, additional, or replaced impervious surface/cover, or in the case of earth disturbance only, less than 5,000 square feet of disturbance, is exempt from this article.
(6)
Repaving without reconstruction.
B.
Exemptions for land development activities.
(2)
These criteria shall apply to the total development even if the development is to take place in phases. The date of the municipal ordinance adoption shall be the starting point from which to consider tracts as "parent tracts" upon which future subdivisions and respective earth disturbance computations shall be cumulatively considered.
(a)
The activities exempted above are still encouraged to implement the stormwater management practices as indicated in Appendix B.[1]
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
(3)
The developer should first determine if the proposed activity will result in the introduction of 500 square feet or more of new, additional, or replacement impervious surface. If not, the developer should next determine if the proposed activity will involve earth disturbance of over 5,000 square feet. If not, then the project is exempt from the SWM site plan requirements. Examples:
(a)
A project introducing 500 square feet of impervious surface, but only 4,900 square feet of earth disturbance is regulated by this article.
(b)
A project involving 5,100 square feet of earth disturbance, but resulting in 400 square feet of impervious surface is regulated.
(c)
A project introducing 400 square feet of impervious surface and involving 4,900 square feet of earth disturbance is exempt from the SWM site plan requirements of this article.
C.
Additional exemption criteria:
(1)
Exemption responsibilities. An exemption shall not relieve the applicant from implementing such measures as are necessary to protect public health, safety, and property.
(2)
HQ and EV streams. An exemption shall not relieve the applicant from meeting the special requirements for watersheds draining to identified high quality (HQ) or exceptional value (EV) waters and source water protection areas (SWPA) and requirements for nonstructural project design sequencing (§ 78-33).
(3)
Drainage problems. If a drainage problem is documented or known to exist downstream of or is expected from the proposed activity, then Haverford Township may require the applicant to comply with this article.
(4)
Emergency exemption. Emergency maintenance work performed for the protection of public health, safety, and welfare. A written description of the scope and extent of any emergency work performed shall be submitted to the Township of Haverford within two calendar days of the commencement of the activity. If the Township of Haverford finds that the work is not an emergency, then the work shall cease immediately, and the requirements of this article shall be addressed as applicable.
(5)
Maintenance exemption. Any maintenance to an existing stormwater management system made in accordance with plans and specifications approved by the Township Engineer or the Township of Haverford.
(6)
Even though the developer is exempt, they are not relieved from complying with other regulations.
Any other ordinance provision(s) or regulation of the municipality inconsistent with any of the provisions of this article is hereby repealed to the extent of the inconsistency only.
In the event that a court of competent jurisdiction declares any section or provision of this article invalid, such decision shall not affect the validity of any of the remaining provisions of this article.
A.
Approvals issued and actions taken under this article do not relieve the applicant of the responsibility to secure required permits or approvals for activities regulated by any other code, law, regulation or ordinance.
B.
To the extent that this article imposes more rigorous or stringent requirements for stormwater management, the specific requirements contained in this article shall be followed.
C.
Nothing in this article shall be construed to affect any of Haverford Township's requirements regarding stormwater matters that do not conflict with the provisions of this article, such as local stormwater management design criteria (e.g., inlet spacing, inlet type, collection system design and details, outlet structure design, etc.). Conflicting provisions in other municipal ordinances or regulations shall be construed to retain the requirements of this article addressing state water quality requirements. The requirements of this article shall supersede any conflicting requirements in other municipal ordinances or regulations.
Any permit or authorization issued or approved based on false, misleading or erroneous information provided by an applicant is void without the necessity of any proceedings for revocation. Any work undertaken or use established pursuant to such permit or other authorization is unlawful. No action may be taken by a board, agency or employee of the Township purporting to validate such a violation.
B.
Waivers or modifications of the requirements of this article may be approved by the Township if enforcement will exact undue hardship because of peculiar conditions pertaining to the land in question, provided that the modifications will not be contrary to the public interest and that the purpose of the ordinance is preserved. Cost or financial burden shall not be considered a hardship. Modification may be considered if an alternative standard or approach will provide equal or better achievement of the purpose of the ordinance. A request for modifications shall be in writing and accompany the stormwater management site plan submission. The request shall provide the facts on which the request is based, the provision(s) of the ordinance involved and the proposed modification.
C.
No waiver or modification of any regulated stormwater activity involving earth disturbance greater than or equal to one acre may be granted by the Township unless that action is approved in advance by the Department of Environmental Protection (DEP) or the Delaware County Conservation District.
For the purposes of this article, certain terms and words used herein shall be interpreted as follows:
A.
Words used in the present tense include the future tense; the singular number includes the plural, and the plural number includes the singular; words of masculine gender include feminine gender or nonbinary; and words of feminine gender include masculine gender or nonbinary.
B.
The word "includes" or "including" shall not limit the term to the specific example but is intended to extend its meaning to all other instances of like kind and character.
C.
The word "person" includes an individual, firm, association, organization, partnership, trust, company, corporation, unit of government, or any other similar entity.
D.
The words "shall" and "must" are mandatory; the words "may" and "should" are permissive.
E.
The words "used" or "occupied" include the words "intended, designed, maintained, or arranged to be used, occupied, or maintained."
F. ACCELERATED EROSION AGRICULTURAL ACTIVITY ALTERATION APPLICANT AS-BUILT DRAWINGS BANKFULL BASEFLOW BEST MANAGEMENT PRACTICES (BMP) BIORETENTION BUFFER CHANNEL CHANNEL EROSION CISTERN CONSERVATION DISTRICT CONVEYANCE CULVERT DAM DEPARTMENT DESIGN PROFESSIONAL (QUALIFIED) DESIGN STORM DESIGNEE DETENTION BASIN DETENTION VOLUME DEVELOPER DEVELOPMENT SITE (SITE) DEVELOPMENT, LAND DIAMETER AT BREAST HEIGHT (DBH) DIFFUSED DRAINAGE DISCHARGE DISCHARGE DISCHARGE POINT DISTURBED AREAS DITCH DOWNSLOPE PROPERTY LINE DRAINAGE CONVEYANCE FACILITY DRAINAGE EASEMENT EARTH DISTURBANCE ACTIVITY EMERGENCY SPILLWAY ENCROACHMENT EROSION EROSION AND SEDIMENT (E&S) CONTROL PLAN EVAPOTRANSPIRATION (ET) EXCEPTIONAL VALUE WATERS EXISTING CONDITIONS FEMA FINANCIAL HARDSHIP FLOOD FLOODPLAIN FLOODWAY FLUVIAL GEOMORPHOLOGY FOREST MANAGEMENT/TIMBER OPERATIONS FREEBOARD GRADE(1) GRASSED WATERWAY GREEN INFRASTRUCTURE GROUNDWATER GROUNDWATER RECHARGE HEC-HMS The U.S. Army Corps Of Engineers, Hydrologic Engineering Center (HEC) HIGH QUALITY WATERS HIGH TUNNEL(1) (2) HOTSPOTS HYDROGRAPH HYDROLOGIC REGIME HYDROLOGIC SOIL GROUP (HGS) IMPERVIOUS SURFACE (IMPERVIOUS AREA) IMPOUNDMENT INFILL INFILTRATION INFILTRATION STRUCTURES INFLOW INLET INTERMITTENT STREAM INVERT KARST LAND DEVELOPMENT (DEVELOPMENT) LIMITING ZONE(1) (2) (3) LOT LOW-IMPACT DEVELOPMENT (LID) MAIN STEM (MAIN CHANNEL) MANAGED RELEASE CONCEPT (MRC) MANNING EQUATION (MANNING FORMULA) MAXIMUM DESIGN STORM MUNICIPAL ENGINEER or TOWNSHIP ENGINEER MUNICIPALITY or TOWNSHIP NATURAL CONDITION NATURAL HYDROLOGIC REGIME NATURAL RECHARGE AREA NONPOINT SOURCE POLLUTION NONSTORMWATER DISCHARGES NONSTRUCTURAL BEST MANAGEMENT PRACTICES (BMPs) NPDES NRCS OPEN CHANNEL OUTFALL OUTFLOW OUTLET PARENT TRACT PARKING LOT STORAGE PEAK DISCHARGE PENN STATE RUNOFF MODEL PENNSYLVANIA STORMWATER BEST MANAGEMENT PRACTICES MANUAL — (Document Number 363-0300-002) (December 2006, and as subsequently amended) PERVIOUS AREA PIPE PLANNING COMMISSION POINT SOURCE POSTCONSTRUCTION PRECONSTRUCTION PREDEVELOPMENT CONDITION PRETREATMENT PROJECT SITE QUALIFIED PROFESSIONAL RATIONAL FORMULA REACH RECHARGE RECONSTRUCTION RECORD DRAWINGS REDEVELOPMENT REGULATED ACTIVITIES REGULATED EARTH DISTURBANCE ACTIVITY REGULATED IMPERVIOUS SURFACE RELEASE RATE REPAVING REPLACEMENT PAVING RETENTION BASIN RETENTION VOLUME/REMOVED RUNOFF RETURN PERIOD RIPARIAN RIPARIAN BUFFER RISER ROAD MAINTENANCE ROOF DRAINS ROOFTOP DETENTION RUNOFF SALDO SEDIMENT SEDIMENT BASIN SEDIMENT POLLUTION SEDIMENTATION SEEPAGE PIT/SEEPAGE TRENCH SEPARATE STORM SEWER SYSTEM SHALLOW CONCENTRATED FLOW SHEET FLOW SOIL COVER COMPLEX METHOD SOURCE WATER PROTECTION AREAS (SWPA) SPECIAL PROTECTION SUBWATERSHEDS SPILLWAY STATE WATER QUALITY REQUIREMENTS STORAGE INDICATION METHOD STORM FREQUENCY STORM SEWER STORMWATER STORMWATER CONTROL MEASURE STORMWATER MANAGEMENT DISTRICT STORMWATER MANAGEMENT FACILITY STORMWATER MANAGEMENT PERMIT (SWM PERMIT) STORMWATER MANAGEMENT PLAN STORMWATER MANAGEMENT SITE PLAN (SWM SITE PLAN) STREAM STREAM BUFFER STREAM ENCLOSURE SUBAREA (SUBWATERSHED) SUBDIVISION SURFACE WATERS OF THE COMMONWEALTH SWALE TIMBER OPERATIONS TIME-OF-CONCENTRATION (Tc) TOP-OF-BANK UNDEVELOPED CONDITION USDA VERNAL POND WATERCOURSE WATERS OF THIS COMMONWEALTH WATERSHED WELLHEAD WELLHEAD PROTECTION AREA WET BASIN WETLAND WOODS
As used in this article, the following terms shall have the meanings indicated:
The removal of the surface of the land through the combined action of man's activity and the natural processes at a rate greater than would occur because of the natural process alone.
Activities associated with agriculture such as agricultural cultivation, agricultural operation, and animal heavy use areas. This includes the work of producing crops including tillage, land clearing, plowing, disking, harrowing, planting, harvesting crops or pasturing and raising of livestock and installation of conservation measures. Construction of new buildings or impervious area is not considered an agricultural activity.
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.
A landowner, developer, or other person who has filed an application to the municipality for approval to engage in any regulated activity at a project site in the municipality.
Engineering or site drawings maintained by the contractor as they construct the project and upon which they document the actual locations of the building components and changes to the original contract documents. These documents, or a copy of same, are turned over to the municipal engineer at the completion of the project.
The channel at the top-of-bank or point from where water begins to overflow onto a floodplain.
Portion of stream discharge derived from groundwater; the sustained discharge that does not result from direct runoff or from water diversions, reservoir releases, piped discharges, or other human activities.
Activities, facilities, designs, measures, or procedures used to manage stormwater impacts from regulated activities, to meet state water quality requirements, to promote infiltration, and to otherwise meet the purposes of this article. Stormwater BMPs are commonly grouped into one of two broad categories or measures: "structural" or "nonstructural." In this article, nonstructural BMPs or measures include certain low-impact development practices used to minimize the contact of pollutants with stormwater runoff. These practices aim to limit the total volume of stormwater runoff and manage stormwater at its source by techniques such as protecting natural systems and incorporating existing landscape features. Nonstructural BMPs include, but are not limited to, low-impact development practices such as the protection of sensitive and special value features such as wetlands and riparian areas, the preservation of open space while clustering and concentrating development, the reduction of impervious surface, and the disconnection of rooftops from storm sewers. Structural BMPs are those that consist of a physical to capture and treat stormwater runoff. Structural BMPs include, but are not limited to, a wide variety of practices and devices, from large-scale retention ponds and constructed wetlands to small-scale underground treatment systems, infiltration facilities, filter strips, bioretention, wet ponds, permeable paving, grassed swales, riparian buffers, sand filters, detention basins, and manufactured devices. Structural and nonstructural stormwater BMPs are permanent appurtenances to the project site.
A stormwater retention area that utilizes woody and herbaceous plants and soils to remove pollutants before infiltration occurs.
See "riparian buffer."
An open drainage feature through which stormwater flows. Channels include, but shall not be limited to, natural and man-made drainageways, swales, streams, ditches, canals, and pipes flowing partly full.
The widening, deepening, or headward cutting of channels and waterways caused by stormwater runoff or bankfull flows.
An underground reservoir or tank for storing rainwater.
The Delaware County Conservation District.
A natural or manmade, existing, or proposed Stormwater Management Facility, feature or channel used for the transportation or transmission of stormwater from one place to another. For the purposes of this article, conveyance shall include pipes, drainage ditches, channels, and swales (vegetated and other), gutters, stream channels, and like facilities or features.
A structure with its appurtenant works which carries water under or through an embankment or fill.
A man-made barrier, together with its appurtenant works, constructed for the purpose of impounding or storing water or another fluid or semifluid. A dam may include a refuse bank, fill, or structure for highway, railroad, or other purposes which impounds or may impound water or another fluid or semifluid.
The Pennsylvania Department of Environmental Protection. Also referred to as "DEP," "PA DEP" or "PADEP."
A Pennsylvania-registered professional engineer, registered landscape architect, or registered professional land surveyor trained to develop stormwater management plans, or any person licensed by the Pennsylvania Department of State or qualified by law to perform the work required by the ordinance.
The magnitude and temporal distribution of precipitation from a storm event measured in probability of occurrence (e.g., a five-year storm) and duration (e.g., 24 hours), used in the design and evaluation of stormwater management systems. Also see "return period."
The agent of the Delaware County Planning Department, Delaware County Conservation District, and/or agent of the governing body involved with the administration, review, or enforcement of any provisions of this article by contract or memorandum of understanding.
An impoundment designed to collect and retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. Detention basins are designed to drain completely soon after a rainfall event and become dry until the next rainfall event.
The volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.
A person, or company, or organization who seeks to undertake any regulated earth disturbance activities at a project site in Haverford Township.
See "project site."
Any human-induced change to improved or unimproved real estate, whether public or private, including but not limited to land development, construction, installation, or expansion of a building or other structure, land division, street construction, drilling, and site alteration, such as embankments, dredging, grubbing, grading, paving, parking or storage facilities, excavation, filling, stockpiling, or clearing. As used in this article, development encompasses both new development and redevelopment.
The outside bark diameter at breast height which is defined as 4.5 feet (1.37m) above the forest floor on the uphill side of the tree.
Drainage discharge that is not confined to a single point location or channel, including sheet flow or shallow concentrated flow.
The point of discharge for a stormwater facility.
An unstabilized land area where an earth disturbance activity is occurring or has occurred.
A man-made waterway constructed for irrigation or stormwater conveyance purposes.
That portion of the property line of the lot, tract, or parcels of land being developed, located such that overland or pipe flow from the project site would be directed towards it by gravity.
A stormwater management facility designed to transport stormwater runoff that includes channels, swales, pipes, conduits, culverts, and storm sewers.
A right granted by a landowner to a grantee allowing the use of private land for stormwater management purposes.
A construction or other human activity which disturbs the surface of the land, including, but not limited to: clearing and grubbing; grading; excavations; embankments; road maintenance; building construction; and the moving, depositing, stockpiling, or storing of soil, rock, or earth materials.
A conveyance area that is used to pass peak discharge greater than the maximum design storm controlled by the stormwater facility.
A structure or activity that changes, expands or diminishes the course, current, or cross-section of a watercourse, floodway or body of water.
The natural process by which the surface of the land is worn away by water, wind or chemical action.
A plan that is designed to minimize accelerated erosion and sedimentation. Said plan must be submitted to and approved by the appropriate conservation district before construction can begin.
The combined processes of evaporation from the water or soil surface and transpiration of water by plants.
Surface waters of high quality which satisfy Pennsylvania Code Title 25 Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(b) (relating to antidegradation).
The dominant land cover during the five-year period immediately preceding a proposed regulated activity.
Federal Emergency Management Agency.
A situation where the greatest possible profit cannot be fully realized from development/redevelopment on a given parcel of land due to added costs or burdens associated with the design, construction, and/or maintenance of stormwater structures, facilities, buffers and/or setbacks.
A temporary condition of partial or complete inundation of land areas from the overflow of streams, rivers, and other waters of this commonwealth.
Any land area susceptible to inundation by water from any natural source or delineated by applicable Department of Housing and Urban Development, Federal Emergency Management Agency (FEMA) maps and studies as being a special flood hazard area.
The channel of the watercourse and those portions of the adjoining floodplains that are reasonably required to carry and discharge the 100-year flood (also called the base flood or 1% annual chance flood). Unless otherwise specified, the boundary of the floodway is as indicated on maps and flood insurance studies provided by FEMA. In an area where no FEMA maps or studies have defined the boundary of the 100-year floodway, it is assumed—absent evidence to the contrary—that the floodway extends from the stream to 50 feet from the top of the bank of the stream.
The study of landforms associated with river channels and the processes that form them.
Planning and activities necessary for the management of forestland. These include conducting a timber inventory, preparation of forest management plans, silvicultural treatment, cutting budgets, logging road design and construction, timber harvesting, site preparation, and reforestation.
A vertical distance between the elevation of the design high water and the top of a dam, levee, tank, basin, swale, or diversion berm. The space is required as a safety margin in a pond or basin.
DL1=A. (noun) A slope, usually of a road, channel or natural ground specified in percent and shown on plans as specified herein.
(verb) To finish the surface of a roadbed, the top of an embankment, or the bottom of an excavation.
A natural or man-made waterway, usually broad and shallow, covered with erosion-resistant grasses used to convey surface water.
Systems and practices that use or mimic natural processes to infiltrate, evapotranspire, or reuse stormwater on the site where it is generated. Also referred to as green stormwater infrastructure (GSI).
Water beneath the earth's surface that supplies wells and springs and is often between saturated soil and rock.
The replenishment of existing natural underground water supplies from rain or overland flow.
Hydrologic Modeling System (HMS). This model was used to model the Darby-Cobbs and Crum Creek watersheds during the Act 167 plan development and was the basis for the standards and criteria of this article.
Surface waters having quality which exceeds levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water by satisfying Pennsylvania Code Title 25 Environmental Protection, Chapter 93, Water Quality Standards, § 93.4b(a).
A structure which meets the following:
Is used for the production, processing, keeping, storing, sale or shelter of an agricultural commodity as defined in section 2 of the Act of December 19, 1974 (P.L. 973, No. 319), known as the "Pennsylvania Farmland and Forest Land Assessment Act of 1974," or the storage of agricultural equipment or supplies; and
Areas where land use or activities generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater.
A graph representing the discharge of water versus time for a selected point in the drainage system.
The hydrologic cycle or balance that sustains quality and quantity of stormwater, baseflow, storage and groundwater supplies under natural conditions.
Infiltration rates of soils vary widely and are affected by subsurface permeability as well as surface intake rates. Soils are classified into four HSGs (A, B, C, and D) according to their minimum infiltration rate, which is obtained for bare soil after prolonged wetting. The NRCS defines the four groups and provides a list of most of the soils in the United States and their group classification. The soils in the area of the development site may be identified from a soil survey report that can be obtained from local NRCS offices or conservation district offices. Soils become less pervious as the HSG varies from A to D (NRCS1,2).
Impervious surfaces shall include, but are not limited to, streets, sidewalks, swimming pool surface, pavements, additional indoor living spaces, patios, garages, storage sheds, and similar structures, driveway areas, or roofs, tennis or other paved courts. For the purposes of determining compliance with this article, compacted soils or stone surfaces used for vehicle parking and movement shall be considered impervious. Uncompacted gravel areas with no vehicular traffic shall be considered pervious per review by the Township Engineer. Surfaces that were designed to allow infiltration (i.e. pavers and areas of porous pavement) are to be considered impervious surface, however, may be designed to function as a BMP per review by the Township Engineer. Additionally, for the purposes of determining compliance with this article, the total horizontal projection area of all ground-mounted and free-standing solar collectors, including solar photovoltaic cells, panels, and arrays, shall be considered pervious so long as the Township Engineer determines that the area underneath the solar photovoltaic cells, panels, and arrays is maintained as a vegetated pervious surface.
A retention or detention basin designed to retain stormwater runoff and release it at a controlled rate.
Development that occurs on smaller parcels that remain undeveloped but are within or in very close proximity to urban or densely developed areas. Infill development usually relies on existing infrastructure and does not require an extension of water, sewer, or other public utilities.
Movement of surface water into the soil, where it is absorbed by plant roots, evaporated into the atmosphere, or percolated downward to recharge groundwater.
A structure designed to direct runoff into the underground water (e.g., French drains, seepage pits, or seepage trenches).
The flow entering the stormwater management facility and/or BMP.
The upstream end of any structure through which water may flow.
A stream that flows only part of the time. Flow generally occurs for several weeks or months in response to seasonal precipitation or groundwater discharge.
The lowest surface, the floor or bottom of a culvert, drain, sewer, channel, basin, BMP, or orifice.
A type of topography or landscape characterized by surface depressions, sinkholes, rock pinnacles/uneven bedrock surface, underground drainage, and caves. Karst is formed on carbonate rocks, such as limestone or dolomite.
Inclusive of any or all of the following meanings:
A soil horizon or condition in the soil profile or underlying strata that includes one of the following:
A seasonal high water table, whether perched or regional, determined by direct observation of the water table or indicated by soil mottling.
A rock with open joints, fracture or solution channels, or masses of loose rock fragments, including gravel, with insufficient fine soil to fill the voids between the fragments.
A rock formation, other stratum, or soil condition that is so slowly permeable that it effectively limits downward passage of water.
A designated parcel, tract, or area of land established by a plat or otherwise as permitted by law and to be used, developed, or built upon as a unit.
Site design approaches and small-scale stormwater management practices that promote the use of natural systems for infiltration, evapotranspiration, and reuse of rainwater. LID can be applied to new development, urban retrofits, and revitalization projects. LID utilizes design techniques that infiltrate, filter, evaporate, and store runoff close to its source. Rather than rely on costly large-scale conveyance and treatment systems, LID addresses stormwater through a variety of small, cost-effective landscape features located on-site.
Any stream segment or other runoff conveyance used as a reach in watershed-specific hydrologic models.
A post-construction stormwater management (PCSM) strategy that comprises the collection, management, and filtration of captured runoff from the contributing drainage area through a best management practice (BMP) that is preferably vegetated and includes release of a portion of the captured runoff through an underdrain within the BMP. If the MRC BMP is not vegetated, then pretreatment is required to meet water quality requirements. MRC is intended to be used for project areas or subareas where infiltration is considered infeasible to meet regulatory requirements. Refer to the "Managed Release Concept" Version 1.2 (August 25, 2020) guidance document or latest guidance from PA DEP.
A method for calculation of velocity of flow (e.g., feet per second) and flow rate (e.g., cubic feet per second) in open channels based upon channel shape, roughness, depth of flow, and slope. "Open channels" may include closed conduits so long as the flow is not under pressure.
The maximum (largest) design storm that is controlled by the stormwater facility.
A professional engineer licensed as such in the Commonwealth of Pennsylvania, duly appointed as the Engineer for a municipality, planning agency, or joint planning commission.
Haverford Township, Delaware County, Pennsylvania.
Predevelopment condition.
See "hydrologic regime."
Undisturbed surface area or depression where stormwater collects and a portion of which infiltrates and replenishes the underground and groundwater.
Pollution that enters a water body from diffuse origins in the watershed and does not result from discernible, confined, or discrete conveyances.
Water flowing in stormwater collection facilities, such as pipes or swales, which is not the result of a rainfall event or snowmelt.
Methods of controlling stormwater runoff quantity and quality, such as innovative site planning, impervious area and grading reduction, protection of natural depression areas, temporary ponding on site, and other techniques.
National Pollutant Discharge Elimination System, the federal government's system for issuance of permits under the Clean Water Act, which is delegated to DEP in Pennsylvania.
Natural Resource Conservation Service (previously SCS).
A conveyance channel that is not enclosed.
"Point source," as described in 40 CFR § 122.2, at the point where Haverford Township's storm sewer system discharges to surface waters of the commonwealth.
The flow exiting the stormwater management facility and/or BMP.
Points of water disposal to a stream, river, lake, tidewater, or artificial drain.
The parcel of land from which a land development or subdivision originates, determined from the date of municipal adoption of this article.
Involves the use of parking areas as temporary impoundments with controlled release rates during rainstorms.
The maximum rate of stormwater runoff from a specific storm event.
The computer-based hydrologic model developed at Pennsylvania State University.
The Best Management Practices Manual published by the Pennsylvania Department of Environmental Protection. The manual is to supplement federal and state regulations and the Department of Environmental Protection's Comprehensive Stormwater Management Policy that emphasizes effective site planning as the preferred method of managing runoff while also providing numerous examples of BMPs that can be employed in Pennsylvania to further avoid and minimize flooding and water resource problems.
Any area not defined as impervious.
A culvert, closed conduit, or similar structure (including appurtenances) that conveys stormwater.
The Planning Commission of Haverford Township.
Any discernible, confined, and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel or conduit from which stormwater is or may be discharged, as defined in state regulations at 25 Pennsylvania Code § 92.1.
Period after construction during which disturbed areas are stabilized, stormwater controls are in place and functioning, and all proposed improvements in the approved land development plan are completed.
Prior to commencing construction activities.
Undeveloped/natural condition.
Techniques employed in stormwater BMPs to provide storage or filtering to trap coarse materials and other pollutants before they enter the system, but not necessarily designed to meet the water quality volume requirements of § 78-37.
The specific area of land where any regulated activities in Haverford Township are planned, conducted or maintained.
Any person licensed by the Pennsylvania Department of State or otherwise qualified by law to perform the work required by this article.
A rainfall-runoff relation used to estimate peak flow.
Any stream segment or other runoff conveyance used in the watershed-specific hydrologic models.
The replenishment of groundwater through the infiltration of rainfall, other surface waters, or land application of water or treated wastewater.
Demolition and subsequent rebuilding of impervious surface.
Original documents revised to suit the as-built conditions and subsequently provided by the engineer to the client. The engineer reviews the contractor's as-builts against their own records for completeness, then either turns these over to the client or transfers the information to a set of reproducibles, in both cases for the client's permanent records.
Any development that requires demolition or removal of existing structures or impervious surfaces at a site and replacement with new impervious surfaces. Maintenance activities such as top-layer grinding and repaving are not considered to be redevelopment. Interior remodeling projects and tenant improvements are also not considered to be redevelopment.
Any earth disturbance activities or any activities that involve the alteration or development of land in a manner that may affect stormwater runoff. Actions or proposed actions that have an impact on stormwater runoff quality or quantity and that are specified in § 78-17 of this article.
Activity involving earth disturbance subject to regulation under 25 Pa. Code 92, 25 Pa. Code 102, or the Clean Streams Law. Defined under NPDES Phase II regulations as earth disturbance activity of one acre or more with a point source discharge to surface waters or Haverford Township's storm sewer system or five acres or more regardless of the planned runoff. This includes earth disturbance on any portion of, part, or during any stage of a larger common plan of development.
Proposed impervious surface as part of a current proposed activity and all existing impervious surfaces installed after February 15, 2005 as part of a previous activity.
The percentage of existing conditions' peak rate of runoff from a site or subarea to which the proposed conditions' peak rate of runoff must be reduced to protect downstream areas.
Replacement of the impervious surface that does not involve reconstruction of an existing paved (impervious) surface.
Reconstruction of and full replacement of an existing paved (impervious) surface.
A structure in which stormwater is stored and not released during the storm event. Retention basins are designed for infiltration purposes and do not have an outlet. The retention basin must infiltrate stored water in four days or less.
The volume of runoff that is captured and not released directly into the surface waters of this Commonwealth during or after a storm event.
The average interval, in years, within which a storm event of a given magnitude can be expected to occur one time. For example, the twenty-five-year return period rainfall would be expected to occur on average once every 25 years; or stated in another way, the probability of a twenty-five-year storm occurring in any one year is 0.04 (i.e., a 4% chance).
Pertaining to anything connected with or immediately adjacent to the banks of a stream or other body of water.
An area of land adjacent to a body of water and managed to maintain the integrity of stream channels and shorelines to 1) reduce the impact of upland sources of pollution by trapping, filtering, and converting sediments, nutrients, and other chemicals, and 2) supply food, cover and thermal protection to fish and other wildlife.
A vertical pipe extending from the bottom of a pond that is used to control the discharge rate from the pond for a specified design storm.
Earth disturbance activities within the existing road cross section, such as grading and repairing existing unpaved road surfaces, cutting road banks, cleaning or clearing drainage ditches, and other similar activities.
A drainage conduit or pipe that collects water runoff from a roof and leads it away from the structure.
The temporary ponding and gradual release of stormwater falling directly onto flat roof surfaces using controlled-flow roof drains in building designs.
Any part of precipitation that flows over the land surface.
Subdivision and Land Development Ordinance.[1]
Soils or other materials transported by surface water as a product of erosion.
A barrier, dam, or retention or detention basin located and designed in such a way as to retain rock, sand, gravel, silt, or other material transported by water during construction.
The placement, discharge, or any other introduction of sediment into the waters of the commonwealth.
The process by which mineral or organic matter is accumulated or deposited by the movement of water or air.
An area of excavated earth filled with loose stone or similar coarse material into which surface water is directed for infiltration into the underground water.
A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains) primarily used for collecting and conveying stormwater runoff.
Stormwater runoff flowing in shallow, defined ruts prior to entering a defined channel or waterway.
A flow process associated with broad, shallow water movement on sloping ground surfaces that is not channelized or concentrated.
A method of runoff computation developed by NRCS that is based on relating soil type and land use/cover to a runoff parameter called curve number (CN).
The zone through which contaminants, if present, are likely to migrate and reach a drinking water well or surface water intake.
Watersheds that have been designated by DEP as EV or HQ waters.
A conveyance that is used to pass the peak discharge of the maximum design storm that is controlled by the stormwater facility.
The regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code and the Clean Streams Law.
A reservoir routing procedure based on solution of the continuity equation (inflow minus outflow equals the change in storage) with outflow defined as a function of storage volume and depth.
The number of times that a given storm "event" occurs or is exceeded on the average in a stated period of years (see "return period").
A system of pipes and/or open channels that conveys intercepted runoff and stormwater from other sources but excludes domestic sewage and industrial wastes.
Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.
Physical features used to effectively control, minimize, and treat stormwater runoff. Also may be referred to as stormwater management practice (SMP). [See best management practice (BMP)].
Those subareas of a watershed in which some type of detention is required to meet the plan requirements and the goals of Act 167.
Any structure, natural or man-made, that, due to its condition, design, or construction, conveys, stores, or otherwise affects stormwater runoff quality, rate, or quantity, including best management practices and stormwater control measures. Typical stormwater management facilities include, but are not limited to: detention and retention basins, open channels, storm sewers, pipes, and infiltration facilities.
A permit issued by Haverford Township after the SWM Site plan has been approved.
The watershed plan, known as the "Darby and Cobbs Creeks Watershed Act 167 Stormwater Management Plan," for managing those land use activities that will influence stormwater runoff quality and quantity and that would impact the Darby and Cobbs Creeks watershed adopted by Delaware County, Chester County, Montgomery County and Philadelphia County as required by the Act of October 4, 1978, P.L. 864 (Act 167).
The plan prepared by the developer or his representative indicating how stormwater runoff will be managed at the development site in accordance with this article. Stormwater management site plan will be designated as SWM site plan throughout this article.
A natural watercourse.
The land area adjacent to each side of a stream essential to maintaining water quality (see "buffer").
A bridge, culvert, or other structure in excess of 100 feet in length upstream to downstream which encloses a regulated water of the commonwealth.
The smallest drainage unit of a watershed for which stormwater management criteria have been established in the stormwater management plan.
As defined in the Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, No. 247; The division or redivision of a lot, tract, or parcel of land by any means into two or more lots, tracts, parcels, or other divisions of land including changes in existing lot lines for the purpose, whether immediate or future, of lease, partition by the court for distribution to heirs or devisees, transfer of ownership, or building or lot development; provided, however, that the subdivision by lease of land for agricultural purposes into parcels of more than 10 acres not involving any new street or easement of access or any residential dwelling shall be exempted.
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 waters, or parts thereof, whether natural or artificial, within or on the boundaries of the commonwealth.
A low-lying stretch of land that gathers or carries surface water runoff.
See "forest management."
The time required 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.
Highest point of elevation in a stream channel cross section at which a rising water level just begins to flow out of the channel and over the floodplain.
Natural condition (see also "predevelopment condition").
United States Department of Agriculture.
Seasonal depressional wetlands that are covered by shallow water for variable periods from winter to spring but may be completely dry for most of the summer and fall.
A channel or conveyance of surface water having a defined bed and banks, whether natural or artificial, with perennial or intermittent flow.
Any and all rivers, streams, creeks, rivulets, impoundments, ditches, watercourses, storm sewers, lakes, dammed water, wetlands, ponds, springs, and all other bodies or channels of conveyance of surface and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of this commonwealth.
Region or area drained by a river, watercourse, or other surface water of this commonwealth.
The surface and subsurface area surrounding a water supply well, well field, or spring supplying a public water system through which contaminants are reasonably likely to move toward and reach the water source.
Pond for urban runoff management that is designed to detain urban runoff and always contains water.
Areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs, and similar areas.
A natural ground cover with more than one viable tree of a DBH of six inches or greater per 1,500 square feet which existed within three years of application; a cover condition for which SCS curve numbers have been assigned or to which equivalent rational method runoff coefficients have been assigned.
For any of the activities regulated by this article, the preliminary or final approval of subdivision and/or land development plans, the issuance of any building or occupancy permit, or the commencement of any earth disturbance activity may not proceed until the property owner or applicant or their agent has received written approval of a SWM site plan from Haverford Township and an adequate erosion and sediment control plan review by the Conservation District.
The SWM site plan shall consist of a general description of the project including sequencing items described in § 78-35 [Nonstructural project design (sequencing to minimize stormwater impacts)], calculations, maps, and plans. A note on the maps shall refer to the associated computations and erosion and sediment control plan by title and date. The cover sheet of the computations and erosion and sediment control plan shall refer to the associated maps by title and date. All SWM site plan materials shall be submitted to Haverford Township in a format that is clear, concise, legible, neat, and well organized; otherwise, the SWM Site plan shall not be accepted for review and shall be returned to the applicant. The following items shall be included in the SWM site plan:
A.
General.
(1)
General description of the project including those areas described in § 78-35 [Nonstructural project design (sequencing to minimize stormwater impacts)].
(2)
General description of proposed permanent stormwater management techniques, including construction specifications of the materials to be used for stormwater management facilities.
(3)
Complete hydrologic, hydraulic, and structural computations for all stormwater management facilities.
(4)
An erosion and sediment control plan, including all reviews and letters of adequacy from the Conservation District.
(5)
A general description of proposed nonpoint source pollution controls.
(6)
A justification must be included in the SWM site plan if BMPs other than green infrastructure methods and LID practices are proposed to achieve the volume, rate, and water quality controls under this article.
(7)
The SWM site plan Application and completed fee schedule form and associated fee (Appendix C-1).[1]
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
(8)
The SWM site plan Checklist (Appendix C-2).
B.
Maps or plan sheets. Map(s) or plan sheets of the project area shall be submitted on twenty-four-inch by thirty-six-inch sheets and/or shall be prepared in a form that meets the requirements for recording at the offices of the Recorder of Deeds of Delaware County. If the SALDO[2] has more stringent criteria than this article, then the more stringent criteria shall apply. The contents of the map(s) shall include, but not be limited to:
(1)
The location of the project relative to highways, municipal boundaries, or other identifiable landmarks.
(2)
Existing contours at intervals of two feet.
(3)
Existing streams, lakes, ponds, or other waters of the commonwealth within the project area.
(4)
Other physical features including flood hazard boundaries, stream buffers, existing drainage courses, areas of natural vegetation to be preserved, and the total extent of the upstream area draining through the site.
(5)
The locations of all existing and proposed utilities, sanitary sewers, and water lines within 50 feet of property lines.
(6)
An overlay showing soil names and boundaries.
(7)
Limits of earth disturbance, including the type and amount of impervious area that would be added.
(8)
Proposed structures, roads, paved areas, and buildings.
(9)
Final contours at intervals of two feet.
(10)
The name of the development, the name and address of the owner of the property, and the name of the individual or firm preparing the plan.
(11)
The date of submission.
(12)
A graphic and written scale of one-inch equals no more than 50 feet; for tracts of 20 acres or more, the scale shall be one inch equals no more than 100 feet.
(13)
A north arrow.
(14)
The total tract boundary and size with distances marked to the nearest foot and bearings to the nearest degree.
(15)
Existing and proposed land use(s).
(16)
A key map showing all existing man-made features beyond the property boundary that would be affected by the project.
(17)
Location of all open channels.
(18)
Overland drainage patterns and swales.
(19)
A fifteen-foot-wide access easement around all stormwater management facilities that would provide ingress to and egress from a public right-of-way.
(20)
The location of all erosion and sediment control facilities.
(21)
A note on the plan indicating the location and responsibility for maintenance of stormwater management facilities that would be located off site. All off-site facilities shall meet the performance standards and design criteria specified in this article.
(22)
A statement, signed by the applicant, acknowledging that any revision to the approved SWM site plan must be approved by Haverford Township, and that a revised erosion and sediment control plan must be submitted to the Conservation District for a determination of adequacy.
(23)
The following signature block signed and sealed by the qualified licensed professional responsible for the preparation of the SWM site plan:
"I, (Licensed Professional), on this date (date of signature), hereby certify that the SWM site plan meets all design standards and criteria of the Haverford Township Stormwater Management Code."
(24)
The following signature block for the municipality:
"On behalf of Haverford Township, (Municipal Official or Designee), on this date (date of signature), has reviewed and hereby certifies to the best of my knowledge that the SWM site plan meets all design standards and criteria of the Haverford Township Stormwater Management Ordinance."
C.
Supplemental information to be submitted to Haverford Township.
(1)
A written description of the following information shall be submitted by the applicant and shall include:
(a)
The overall stormwater management concept for the project designed in accordance with § 78-35, Nonstructural project design (sequencing to minimize stormwater impacts).
(b)
Stormwater runoff computations as specified in this article.
(c)
Stormwater management techniques to be applied both during and after development.
(d)
Expected project time schedule.
(e)
Development stages or project phases, if so proposed.
(2)
An erosion and sediment control plan.
(3)
A description of the effect of the project (in terms of runoff volumes and peak flows) on adjacent properties and on any existing municipal stormwater collection system that may receive runoff from the project site.
(4)
A declaration of adequacy and highway occupancy permit from the Pennsylvania Department of Transportation (PennDOT) District office when utilization of a PennDOT storm drainage system is proposed.
D.
Stormwater management facilities.
(1)
All stormwater management facilities must be located on a plan and described in detail.
(2)
The locations of existing and proposed septic tank infiltration areas and wells must be shown.
(3)
All calculations, assumptions, and criteria used in the design of the stormwater management facilities must be shown.
Haverford Township shall require receipt of a complete SWM site plan, as specified in this article.
A.
Proof of application or documentation of required permit(s) or approvals for the programs listed below shall be part of the plan:
B.
C.
For projects that require SALDO approval, the SWM site plan shall be submitted by the applicant as part of the preliminary plan submission where applicable for the regulated activity.
D.
For regulated activities that do not require SALDO approval, see § 78-26, SWM site plan requirements.
E.
Six copies of the SWM site plan shall be submitted and distributed as follows:
F.
Any submissions to the agencies listed above that are found to be incomplete shall not be accepted for review and shall be returned to the applicant with a notification in writing of the specific manner in which the submission is incomplete.
A.
The municipal engineer shall review the SWM site plan for consistency with this article and the respective Act 167 stormwater management plan. Any plan found incomplete shall not be accepted for review and shall be returned to the applicant.
B.
The municipal engineer shall review the SWM site plan for any subdivision or land development against the municipal SALDO provisions not otherwise superseded by this article.
C.
The Conservation District, in accordance with established criteria and procedures, shall review the SWM site plan for consistency with stormwater management and erosion and sediment pollution control requirements and provide comments to Haverford Township. The applicant shall respond to the Conservation District comments on the SWM site plan prior to being considered for final approval by the Township.
D.
For activities regulated by this article, the municipal engineer shall notify the applicant and Haverford Township in writing whether the SWM site plan is consistent with the stormwater management plan ordinance.
(1)
If the municipal engineer determines that the SWM site plan is consistent with the stormwater management ordinance, the municipal engineer shall forward a letter of consistency to the Township who will then forward a copy to the applicant.
(2)
If the municipal engineer determines that the SWM site plan is inconsistent or noncompliant with the stormwater management ordinance, the municipal engineer shall forward a letter to the Township with a copy to the applicant citing the reason(s) and specific code sections for the inconsistency or noncompliance. Inconsistency or noncompliance may be due to inadequate information to make a reasonable judgment as to compliance with the stormwater management plan. Any SWM site plans that are inconsistent or noncompliant may be revised by the applicant and resubmitted when consistent with this article.
E.
For regulated activities specified in § 78-17, Applicability and regulated activities, of this article that require a building permit, the municipal engineer shall notify the municipal building permit officer in writing whether the SWM site plan is consistent with the stormwater management ordinance. The municipal building permit officer shall forward a copy of the consistency/inconsistency letter to the applicant. Any SWM site plan deemed inconsistent may be revised by the applicant and resubmitted consistent with this article.
F.
For regulated activities under this article that require an NPDES permit application, the applicant shall forward a copy of the Township Engineer's letter stating that the SWM site plan is consistent with the stormwater management ordinance to the Conservation District. DEP and the Conservation District may consider the Township Engineer's review comments in determining whether to issue a permit.
G.
Haverford Township shall not grant preliminary or final approval to any subdivision or land development for regulated activities specified in § 78-17, Applicability and regulated activities, of this article if the SWM site plan has been found by the Township Engineer to be inconsistent with the stormwater management ordinance. All required permits from DEP must be obtained prior to approval of any subdivision or land development.
H.
No building permits for any regulated activity specified in § 78-17, Applicability and regulated activities of this article shall be approved by Haverford Township if the SWM site plan has been found to be inconsistent with the stormwater management plan, as determined by the Township Engineer and Conservation District, or without considering the comments of the Township Engineer and Conservation District. All required permits from DEP must be obtained prior to issuance of a building permit.
I.
The applicant shall be responsible for completing record drawings of all stormwater management facilities included in the approved SWM site plan. The record drawings and an explanation of any discrepancies with the design plans shall be submitted to the Township Engineer for final approval. In no case shall Haverford Township approve the record drawings until Haverford Township receives a copy of an approved declaration of adequacy and/or highway occupancy permit from the PennDOT District office, NPDES permit, and any other applicable permits or approvals from DEP or the Conservation District. The above permits and approvals must be based on the record drawings.
J.
Haverford Township's approval of a SWM site plan shall be valid for a period not to exceed five years commencing on the date that Haverford Township signs the approved SWM site plan. If stormwater management facilities included in the approved SWM site plan have not been constructed, or if constructed, record drawings of these facilities have not been approved within this five-year time period, then Haverford Township may consider the SWM site plan inconsistent or noncompliant and may revoke any and all permits. SWM site plans that are determined to be inconsistent or noncompliant by Haverford Township shall be resubmitted in accordance with § 78-30, Resubmission of inconsistent or noncompliant SWM site plans, of this article.
A.
A revision to a submitted SWM site plan under review by Haverford Township for a development site that involves the following shall require a resubmission to Haverford Township of a revised SWM site plan consistent with § 78-26 of this article and be subject to review as specified in § 78-28 of this article:
B.
A revision to an already approved or inconsistent or noncompliant SWM site plan shall be submitted to Haverford Township, accompanied by the applicable municipal review and inspection fee. A revision to a SWM site plan for which a formal action has not been taken by Haverford Township shall be submitted to Haverford Township accompanied by the applicable municipal review and inspection fee.
An inconsistent or noncompliant SWM site plan may be resubmitted with the revisions addressing the Township Engineer's concerns documented in writing. It must be addressed to Haverford Township in accordance with § 78-27 contents of this article, distributed accordingly, and be subject to review as specified in § 78-28 of this article. The applicable Township review and inspection fee must accompany a resubmission of an inconsistent or noncompliant SWM site plan.
A.
Applicants proposing regulated activities in Haverford Township which do not fall under the exemption criteria shown in § 78-18 shall submit a stormwater management site plan consistent with this article and the applicable watershed stormwater management plan to Haverford Township for review. The stormwater management criteria of this article shall apply to the total proposed development even if development is to take place in stages.
B.
The applicant is required to design the site to minimize surface discharge of stormwater and the creation of impervious surfaces in order to maintain, as much as possible, the natural hydrologic regime.
C.
The SWM site plan must be designed consistent with the sequencing provisions of § 78-35 to ensure maintenance of the natural hydrologic regime, to promote infiltration, and to protect groundwater and surface water quality and quantity. The SWM site plan designer must proceed sequentially in accordance with this article.
D.
Stormwater drainage systems shall be designed in order to preserve natural flow conditions to the maximum extent practicable.
E.
Alteration of existing drainage discharge onto adjacent property shall only be proposed in accordance with PADEP guidance document "Chapter 102 Off-Site Discharges of Stormwater to Non-Surface Waters - Frequently Asked Questions (FAQ)" dated January 2, 2019, or latest guidance document from PADEP. Such discharge shall be subject to any applicable discharge criteria specified in this article and still must meet the requirements of Act 167.
F.
Areas of existing diffused drainage discharge, whether proposed to be concentrated or maintained as diffused drainage areas, shall be subject to any applicable discharge criteria in the general direction of existing discharge, except as otherwise provided by this article. If diffused drainage discharge is proposed to be concentrated and discharged onto adjacent property, the applicant must document that adequate downstream conveyance facilities exist to safely transport the concentrated discharge or otherwise prove that no erosion, sedimentation, flooding, or other impacts will result from the concentrated discharge.
G.
Where a development site is traversed by a stream, drainage easements shall be provided on either side of, and conform to the line of such streams. The terms of the easement shall conform to the stream buffer requirements contained in § 78-42.
H.
Any stormwater management facilities regulated by this article that would be located in or adjacent to waters of the commonwealth or delineated wetlands shall be subject to approval by DEP through the joint permit application or the environmental assessment approval process or, where deemed appropriate, by the DEP general permit process. When there is a question as to whether wetlands may be involved, it is the responsibility of the applicant or his agent to show that the land in question cannot be classified as wetlands; otherwise, approval to work in the area must be obtained from DEP.
I.
Any proposed stormwater management facilities regulated by this article that would be located on state highway rights-of-way shall be subject to approval by PennDOT.
J.
Minimization of impervious surfaces and infiltration of runoff through seepage beds, infiltration trenches, etc., is encouraged where soil conditions permit in order to reduce the size or eliminate the need for detention facilities or other structural BMPs.
K.
Rooftop runoff may go directly to an infiltration BMP or be evapotranspirated.
L.
All regulated activities within the municipality shall be designed, implemented, operated, and maintained to meet the purposes of this article, through these two elements:
M.
No regulated activity within the municipality shall commence until the municipality issues approval of a SWM plan, which demonstrates compliance with the requirements of this article.
N.
The BMPs shall be designed, implemented, and maintained to meet state water quality requirements and any other more stringent requirements as determined by the Township. Applicants shall utilize the Pennsylvania Stormwater Best Management Practices Manual (PA BMP Manual), as amended, or other sources acceptable to the Township Engineer, for testing and design standards for BMPs, and where there is a conflict with the provisions of this article, the most restrictive applies.
P.
Operations and maintenance of permanent stormwater BMPs shall be addressed as required by this article.
Q.
All BMPs used to meet the requirements of this article shall conform to the state water quality requirements and any more stringent requirements as set forth by Haverford Township.
R.
Techniques described in Appendix E[1] (Low-Impact Development) of this article and green infrastructure methods shall be prioritized because they reduce the costs of complying with the requirements of this article and the state water quality requirements.
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
S.
In selecting the appropriate BMPs or combinations thereof, the applicant shall consider the following:
(1)
Total contributing drainage area.
(2)
Permeability and infiltration rate of the site's soils.
(3)
Slope and depth to bedrock.
(4)
Seasonal high water table.
(5)
Proximity to building foundations and wellheads.
(6)
Erodibility of soils.
(7)
Land availability and configuration of the topography.
(8)
Peak discharge and required volume control.
(9)
Stream bank erosion.
(10)
Efficiency of the BMPs to mitigate potential water quality problems.
(11)
The volume of runoff that will be effectively treated.
(12)
The nature of the pollutant being removed.
(13)
Maintenance requirements.
(14)
Creation/protection of aquatic and wildlife habitat.
(15)
Recreational value.
(16)
Enhancement of aesthetic and property values.
T.
The design of all stormwater management facilities shall incorporate sound engineering principles and practices in a manner that does not aggravate existing stormwater problems. The Township reserves the right to disapprove any design that would result in construction in or continuation of a stormwater problem area.
U.
The applicant may meet the stormwater management criteria through off-site stormwater management measures as long as the proposed measures are in the same subwatershed as shown in Ordinance Appendix A.[2]
[2]
Editor's Note: The appendix is included as an attachment to this chapter.
V.
The following standards for protection of adjacent and downgradient properties from off-site conveyance must be accomplished. For any location where a new concentrated discharge of stormwater from any frequency rainfall event, up to and including the 100-year storm and the volume of runoff up to and including the two-year storm onto or through adjacent property(ies) or downgradient property(ies), the following are required:
(1)
A drainage easement (or other legal agreement/approval) must be obtained for conveyance of discharges onto or through adjacent properties per the PADEP guidance document "Chapter 102 Off-Site Discharges of Stormwater to Non-Surface Wasters - Frequently Asked Questions (FAQ)" dated January 2, 2019, or latest guidance document from PADEP.
(2)
The conveyance must be designed to avoid erosion, flooding, or other damage to the properties through which it is being conveyed.
Haverford Township's approval of an SWM site plan authorizes the regulated activities contained in the SWM site plan for a maximum term of validity of five years following the date of approval. The Township may specify a term of validity shorter than five years in the approval for any specific SWM site plan. Terms of validity shall commence on the date the municipality signs the approval for an SWM site plan. If an approved SWM site plan is not completed according to Section § 78-33, Permit requirements by other governmental entities; as-built plans, completion certificate, and final inspection, within the term of validity, then the municipality may consider the SWM site plan disapproved and may revoke any and all permits. SWM site plans that are considered disapproved by the shall be resubmitted in accordance with § 78-30 of this article.
The following permit requirements may apply to certain regulated earth disturbance activities and must be met prior to commencement of regulated earth disturbance activities, as applicable:
A.
All regulated earth disturbance activities subject to permit requirements by DEP under regulations at 25 Pennsylvania Code Chapter 102.
B.
Work within natural drainageways subject to permit by DEP under 25 Pennsylvania Code Chapter 105.
C.
Any stormwater management facility that would be located in or adjacent to surface waters of the commonwealth, including wetlands, subject to permit by DEP under 25 Pennsylvania Code Chapter 105.
D.
Any stormwater management facility that would be located on a state highway right-of-way or require access from a state highway shall be subject to approval by PennDOT.
A.
No regulated earth disturbance activities within Haverford Township shall commence until Haverford Township receives an approval from the Conservation District of an erosion and sediment control plan for construction activities.
B.
DEP has regulations that require an erosion and sediment control plan for any earth disturbance activity of 5,000 square feet or more, under 25 Pennsylvania Code § 102.4(b).
C.
In addition, under 25 Pennsylvania Code Chapter 92, a DEP "NPDES construction activities" permit is required for regulated earth disturbance activities. Evidence of any necessary permit(s) for regulated earth disturbance activities from the appropriate DEP regional office or County Conservation District must be provided to Haverford Township.
D.
Evidence of any necessary permit(s) for regulated earth disturbance activities from the appropriate PA DEP regional office or County Conservation District must be provided to the Township. The issuance of an NPDES construction permit (or permit coverage under the statewide General Permit (PAG-2)) satisfies the requirements of § 78-33.
E.
A copy of the erosion and sediment control plan and any required permit, as required by DEP regulations, shall be available on the project site at all times.
F.
Additional erosion and sediment control design standards and criteria are recommended to be applied where infiltration BMPs are proposed. They shall include the following:
(1)
Areas proposed for infiltration BMPs shall be protected from sedimentation and compaction during the construction phase to maintain maximum infiltration capacity.
(2)
Infiltration BMPs shall not be constructed nor receive runoff until the entire drainage area contributory to the infiltration BMP has achieved final stabilization.
A.
The design of all regulated activities shall include the following to minimize stormwater impacts.
(1)
The applicant shall find practicable alternatives to the surface discharge of stormwater, such as those listed in Appendix F[1], Table F-5, the creation of impervious surfaces, and the degradation of waters of the commonwealth and must maintain as much as possible the natural hydrologic regime of the site.
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
(2)
The applicant shall apply low-impact development (LID) methods such as those listed in Appendix E, provided that use of this method does not conflict with other local codes.
(3)
An alternative is practicable if it is available and capable of implementation after taking into consideration existing technology and logistics in light of overall project purposes and other municipal requirements.
(4)
All practicable alternatives to the discharge of stormwater are presumed to have less adverse impact on quantity and quality of waters of the commonwealth unless otherwise demonstrated.
B.
The applicant shall demonstrate that the regulated activities were designed in the following sequence. The goal of the sequence is to minimize the increases in stormwater runoff and impacts to water quality resulting from the proposed regulated activity:
(1)
Prepare an existing resource and site analysis map (ERSAM) showing environmentally sensitive areas, including but not limited to, steep slopes, ponds, lakes, streams, wetlands, hydric soils, vernal pools, stream buffers and hydrologic soil groups. Land development, any existing recharge areas, and other requirements outlined in the municipal SALDO[2] shall also be included.
(4)
Identify site-specific existing conditions drainage areas, discharge points, recharge areas, and hydrologic soil groups A and B (areas conducive to infiltration).
(6)
Satisfy the infiltration volume requirements (§ 78-36) and provide for stormwater pretreatment prior to infiltration.
(8)
Provide streambank erosion protection in accordance with § 78-38 streambank erosion requirements.
(9)
Determine into what management district the site falls (Appendix A) and conduct an existing conditions runoff analysis.
(10)
Prepare final project design to maintain existing conditions drainage areas and discharge points, to minimize earth disturbance and impervious surfaces and, to the maximum extent possible, to ensure that the remaining site development has no surface or point discharge.
(11)
Conduct a proposed conditions runoff analysis based on the final design that meets the management district requirements (§ 78-39).
(12)
Manage any remaining runoff prior to discharge through detention, bioretention, direct discharge or other structural control.
A.
Providing for infiltration consistent with the natural hydrologic regime is required. Design of the infiltration facilities shall consider infiltration to compensate for the reduction in the recharge that occurs when the ground surface is disturbed or impervious surface is created. It is recommended that roof runoff be directed to infiltration BMPs that may be designed to compensate for the runoff from parking areas. These measures are required to be consistent with § 78-17 and to take advantage of utilizing any existing recharge areas. Infiltration may not be feasible on every site due to site-specific limitations such as soil type. If it cannot be physically accomplished, then the design professional shall be responsible to show that this cannot be physically accomplished.
B.
If it cannot be physically accomplished, then the design professional shall be responsible for demonstrating to the satisfaction of the municipality that this cannot be physically accomplished on the site (e.g., shallow depth to bedrock or limiting zone, open voids, steep slopes, etc. per the PA BMP Manual. A financial hardship as defined in § 78-24 is not acceptable to avoid implementing infiltration facilities. If infiltration can be physically accomplished, the volume of runoff to be infiltrated shall be determined from § 78-36C(2) depending on demonstrated site conditions, and shall be the greatest volume that can be physically infiltrated or alternative methods consistent with the PA BMP Manual (as amended) or other PADEP guidance, such as the Managed Release Concept, may be used to manage this volume with approval from the municipal engineer. For example:
(1)
Any applicant (developer or redeveloper) shall first attempt to infiltrate the volume required in § 78-36C(2)(a).
(2)
If the § 78-36C(2)(a) requirement cannot be physically accomplished, then the applicant is required to attempt to infiltrate the volume required in § 78-36C(2)(b).
(3)
Finally, if the § 78-36C(2)(b) infiltration volume cannot be physically accomplished, the applicant must, at a minimum, infiltrate the volume required in § 78-36C(2)(c).
C.
Infiltration BMPs shall meet the following minimum requirements:
(1)
Infiltration BMPs intended to receive runoff from developed areas shall be selected based on suitability of soils and site conditions and shall be constructed on soils that have the following characteristics:
(a)
A minimum depth of 24 inches between the bottom of the BMP and the top of the limiting zone unless bioretention is used.
(b)
An infiltration rate sufficient to accept the additional stormwater load and dewater completely as determined by field tests conducted by the applicant's design professional.
(c)
The infiltration facility shall be capable of completely infiltrating the retention (infiltration) volume (Rev) below grade within four days (96 hours).
(d)
Pretreatment shall be provided prior to infiltration.
(2)
The size of the infiltration facility shall be based upon the following volume criteria:
(a)
Modified Control Guideline One (MCG-1) of the PA BMP Manual. The retention (infiltration) volume (Rev) to be captured and infiltrated shall be the net two-year twenty-four-hour volume. The net volume is the difference between the post-development runoff volume and the predevelopment runoff volume. The post-development total runoff volume for all storms equal to or less than the two-year twenty-four-hour duration precipitation shall not be increased. For modeling purposes, existing (predevelopment) non-forested pervious areas must be considered meadow in good condition or its equivalent, and 20% of existing impervious area, when present, shall be considered meadow in good condition.
(b)
Infiltrating the entire Rev volume in § 78-36C(2)(a) (above) may not be feasible on every site due to site-specific limitations such as shallow depth to bedrock or the water table. If it cannot be physically accomplished, then the following criteria from Modified Control Guideline Two (MCG-2) of the PA BMP Manual must be satisfied:
At least the first one inch of runoff from new or replacement impervious surfaces shall be infiltrated.
Rev = 1 (inch) * impervious area (square feet) ÷ 12 (inches) = cubic feet (cf)
An asterisk (*) in equations denotes multiplication.
(c)
Only if infiltrating the entire Rev volume in § 78-36C(2)(b) cannot be physically accomplished, then the following minimum criteria from Modified Control Guideline Two (MCG-2) of the PA BMP Manual must be satisfied:
[1]
Wherever possible, infiltration facilities should be designed to accommodate infiltration of the entire water quality volume (WQv) in § 78-36C(2)(a); however, in all cases at least the first 1/2 inch of the WQv shall be infiltrated. The minimum infiltration volume (Rev) required would, therefore, be computed as:
Rev = I * impervious area (square feet) ÷ 12 (inches) = cubic feet (cf)
An asterisk (*) in equations denotes multiplication.
Where:
I = The maximum equivalent infiltration amount (inches) that the site can physically accept or 0.5 inch, whichever is greater.
[2]
The retention volume values derived from the methods in § 78-36C(2)(a), (b), or (c) is the minimum volume the applicant must control through an infiltration BMP facility. If site conditions preclude capture of runoff from portions of the impervious area, the infiltration volume for the remaining area should be increased an equivalent amount to offset the loss.
D.
Soils. A detailed soils evaluation of the project site shall be required to determine the suitability of infiltration facilities. The evaluation shall be performed by a qualified design professional and at a minimum address soil permeability, depth to bedrock, and subgrade stability. The general process for designing the infiltration BMP shall be:
(1)
Analyze hydrologic soil groups as well as natural and man-made features within the site to determine general areas of suitability for infiltration practices. In areas where development on fill material is under consideration, conduct geotechnical investigations of subgrade stability; infiltration may not be ruled out without conducting these tests.
(2)
Provide field tests such as required in the PA BMP Manual.
(3)
Design the infiltration structure for the required retention (Rev) volume based on field-determined capacity at the level of the proposed infiltration surface.
(4)
If on-lot infiltration structures are proposed by the applicant's design professional, it must be demonstrated to Haverford Township that the soils are conducive to infiltrate on the lots identified.
E.
Stormwater hotspots.
(1)
Below is a list of examples of designated hotspots. If a site is designated as a hotspot, it has important implications for how stormwater is managed. First and foremost, untreated stormwater runoff from hotspots shall not be allowed to recharge into groundwater where it may contaminate water supplies. Therefore, the groundwater recharge requirement shall not be applied to development sites that fit into the hotspot category (the entire WQv must still be treated). Second, a greater level of stormwater treatment shall be considered at hotspot sites to prevent pollutant wash off after construction. The Environmental Protection Agency's (EPA) NPDES stormwater program requires some industrial sites to prepare and implement a stormwater pollution prevention plan. Stormwater runoff from hotspots shall be pretreated prior to surface or groundwater infiltration to prevent pollutant runoff. Industrial sites referenced in 40 CFR 125 are examples of hotspots.
(a)
Examples of hotspots:
[1]
Vehicle salvage yards and recycling facilities.
[2]
Vehicle fueling stations.
[3]
Vehicle service and maintenance facilities.
[4]
Vehicle and equipment cleaning facilities.
[5]
Fleet storage areas (bus, truck, etc.).
[6]
Industrial sites based on standard industrial codes.
[7]
Marinas (service and maintenance).
[8]
Outdoor liquid container storage.
[9]
Outdoor loading/unloading facilities.
[10]
Public works storage areas.
[11]
Facilities that generate or store hazardous materials.
[12]
Commercial container nursery.
[13]
Contaminated sites/brownfields.
[14]
Other land uses and activities as designated by an appropriate review authority.
(b)
The following land uses and activities are not normally considered hotspots:
(2)
While large highways [average daily traffic volume (ADT) greater than 30,000] are not designated as stormwater hotspots, it is important to ensure that highway stormwater management plans adequately protect groundwater.
(3)
The Environmental Protection Agency's (EPA) NPDES stormwater program requires some industrial sites to prepare and implement a stormwater pollution prevention plan.
F.
Infiltration facilities should, to the greatest extent practicable, be located to avoid introducing contaminants via groundwater, and be in conformance with an approved source water protection assessment or source water protection plan.
G.
Roadway drainage systems should provide an opportunity to capture accidental spills. Road de-icing material storage facilities shall be designed to avoid salt and chloride runoff from entering waterways and infiltration facilities. The qualified design professional shall evaluate the possibility of groundwater contamination from the proposed infiltration facility and perform a hydrologic justification study if possible.
H.
Extreme caution shall be exercised where infiltration is proposed in SWPAs as defined by the local municipality or water authority.
I.
Infiltration facilities shall be used in conjunction with other innovative or traditional BMPs, stormwater control facilities, and nonstructural stormwater management alternatives.
J.
Extreme caution shall be exercised where salt or chloride (municipal salt storage) would be a pollutant since soils do little to filter this pollutant, and it may contaminate the groundwater. The qualified design professional shall evaluate the possibility of groundwater contamination from the proposed infiltration facility and perform a hydrogeologic justification study if necessary.
K.
The antidegradation analysis found in Chapter 93 shall be applied in HQ or EV streams.
L.
An impermeable liner will be required in detention basins where the possibility of groundwater contamination exists. A detailed hydrogeologic investigation may be required by Haverford Township.
M.
Haverford Township shall require the applicant to provide safeguards against groundwater contamination for land uses that may cause groundwater contamination should there be a mishap or spill.
The applicant shall comply with the following water quality requirements of this article.
A.
No regulated earth disturbance activities within Haverford Township shall commence until approval by Haverford Township of a plan which demonstrates compliance with postconstruction state water quality requirements.
B.
The BMPs shall be designed, implemented, and maintained to meet state water quality requirements and any other more stringent requirements as determined by Haverford Township.
C.
To control post-construction stormwater impacts from regulated activities and conform to state water quality requirements, BMPs which replicate predevelopment stormwater infiltration and runoff conditions must be provided in the site design such that post-construction stormwater discharges do not degrade the physical, chemical, or biological characteristics of the receiving waters. The green infrastructure and low-impact Development (LID) practices provided in the PA BMP Manual, as well as the guidance on green infrastructure and LID provided in Appendix E[1] shall be utilized for all regulated activities wherever possible. This may be achieved by the following:
(1)
Infiltration: replication of preconstruction stormwater infiltration conditions;
(2)
Treatment: use of water quality treatment BMPs to ensure filtering out of the chemical and physical pollutants from the stormwater runoff; and
(3)
Streambank and streambed protection: management of volume and rate of postconstruction stormwater discharges to prevent physical degradation of receiving waters (e.g., from scouring).
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
D.
Developed areas shall provide adequate storage and treatment facilities necessary to capture and treat stormwater runoff. The infiltration volume computed under § 78-36 may be a component of the water quality volume if the applicant chooses to manage both components in a single facility. If the infiltration volume is less than the water quality volume, the remaining water quality volume may be captured and treated by methods other than infiltration BMPs. The required water quality volume (WQv) is the storage capacity needed to capture and treat a portion of stormwater runoff from the developed areas of the site.
(1)
To achieve this goal, the following criterion is established:
(a)
The post-construction total runoff volume shall not exceed the predevelopment total runoff volume for all storms equal to or less than the two-year, twenty-four-hour duration precipitation (design storm). If the Township Engineer concurs that this criterion cannot be met, a minimum of 1/2 inches of runoff from all regulated impervious surfaces shall be managed. For modeling purposes, existing (predevelopment) nonforested pervious areas must be considered meadow in good condition or its equivalent, and 20% of existing impervious area, when present, shall be considered meadow in good condition.
(b)
This volume requirement can be managed by the permanent volume of a wet basin or the detained volume from other BMPs. Where appropriate, wet basins shall be utilized for water quality control and shall follow the guidelines of the PA BMP Manual referenced in Appendix G.
(c)
Release of water can begin at the the start of the storm (i.e., the invert of the water quality orifice is at the inver of the facility). The design of the facility shall provide for protection from clogging and unwanted sedimentation.
E.
For areas within defined special protection subwatersheds that include EV and HQ waters, the temperature and quality of water and streams shall be maintained through the use of temperature-sensitive BMPs and stormwater conveyance systems.
F.
To accomplish the above, the applicant shall submit original and innovative designs to the Township engineer for review and approval. Such designs may achieve the water quality objectives through a combination of different BMPs.
G.
Evapotranspiration may be quantified and credited towards meeting volume requirements according to the PADEP Post Construction Stormwater Management (PCSM) Spreadsheet and Instructions (December 2020) or the most recent guidance from PADEP.
H.
Evidence of any necessary permit(s) for regulated earth disturbance activities from the appropriate DEP regional office must be provided to Haverford Township.
A.
In addition to the control of water quality volume (in order to minimize the impact of stormwater runoff on downstream streambank erosion), the primary requirement is to design a BMP to detain the proposed conditions two-year, twenty-four-hour design storm to the existing conditions one-year flow using the SCS Type II distribution. Additionally, provisions shall be made (such as adding a small orifice at the bottom of the outlet structure) so that the proposed conditions one-year storm takes a minimum of 24 hours to drain from the facility from a point where the maximum volume of water from the one-year storm is captured (i.e., the maximum water surface elevation is achieved in the facility). Release of water can begin at the start of the storm (i.e., the invert of the water quality orifice is at the invert of the facility).
B.
The minimum orifice size in the outlet structure to the BMP shall be three inches in diameter where possible, and a trash rack shall be installed to prevent clogging. On sites with small drainage areas contributing to this BMP that do not provide enough runoff volume to allow a twenty-four-hour attenuation with the three-inch orifice, the calculations shall be submitted showing this condition. Orifice sizes less than three inches can be utilized, provided that the design will prevent clogging of the intake.
C.
In "Conditional Direct Discharge Districts" (District C) only (see § 78-39), the objective is not to attenuate the storms greater than the two-year recurrence interval. This can be accomplished by configuring the outlet structure not to control the larger storms or by a bypass channel that diverts only the two-year stormwater runoff into the basin or conversely, diverts flows in excess of the two-year storm away from the basin.
A.
The Darby and Cobbs Creeks watershed has been divided into stormwater management districts as shown on the Management District Map in Appendix A.[1] In addition to the requirements specified in Table 408.1 below, the erosion and sedimentation control (§ 78-34), the nonstructural project design (§ 78-35), the infiltration volume requirements (§ 78-36), the water quality (§ 78-37), and the streambank erosion (§ 78-38) requirements shall be implemented.
(1)
Standards for managing runoff from each subarea in the Darby and Cobbs Creeks watershed for the two-, five-, ten-, twenty-five-, fifty-, and 100-year design storms are shown in Table 408.1. Development sites located in each of the management districts must control proposed conditions runoff rates to existing conditions runoff rates for the design storms in accordance with Table 408.1.
Table 408.1 Peak Rate Control Standards by Stormwater Management District in the Darby-Cobbs Creek Watershed | ||||
|---|---|---|---|---|
District | Proposed Storm | Condition | Design | Existing Condition Design Storm |
A | 2-year | 1-year | ||
5-year | 5-year | |||
10-year | 10-year | |||
25-year | 25-year | |||
100-year | 100-year | |||
B-1 | 2-year | 1-year | ||
10-year | 5-year | |||
25-year | 10-year | |||
50-year | 25-year | |||
100-year | 100-year | |||
B-2 | 2-year | 1-year | ||
5-year | 2-year | |||
25-year | 5-year | |||
50-year | 10-year | |||
100-year | 100-year | |||
C | Conditional Direct Discharge District | |||
(2)
In District C, development sites that can discharge directly to the Darby-Cobbs Creek main channel, major tributaries, or indirectly to the main channel through an existing stormwater drainage system (i.e., storm sewer or tributary) may do so without control of the proposed conditions peak rate of runoff greater than the five-year storm. Sites in District C will still have to comply with the groundwater recharge and infiltration volume requirement criteria, the water quality criteria, and streambank erosion criteria. If the proposed conditions runoff is intended to be conveyed by an existing stormwater drainage system to the main channel, assurance must be provided that such system has adequate capacity to convey the flows greater than the two-year existing conditions peak flow or will be provided with improvements to furnish the required capacity. When adequate capacity in the downstream system does not exist and will not be provided through improvements, the proposed conditions peak rate of runoff must be controlled to the existing conditions peak rate as required in District A provisions (i.e., ten-year proposed conditions flows to ten-year existing conditions flows) for the specified design storms.
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
B.
General. Proposed conditions rates of runoff from any regulated activity shall not exceed the peak release rates of runoff from existing conditions for the design storms specified on the Stormwater Management District Watershed Map (Appendix A[2]) and this section of the article.
[2]
Editor's Note: The appendix is included as an attachment to this chapter.
C.
District boundaries. The boundaries of the stormwater management districts are shown on an official map that is available for inspection at the municipal and County Planning offices. A copy of the official map at a reduced scale is included in Appendix A. The exact location of the stormwater management district boundaries as they apply to a given development site shall be determined by mapping the boundaries using the two-foot topographic contours (or most accurate data required) provided as part of the SWM site plan.
D.
Sites located in more than one district. For a proposed development site located within two or more stormwater management district category subareas, the peak discharge rate from any subarea shall meet the management district criteria for which the discharge is located. The calculated peak discharges shall apply regardless of whether the grading plan changes the drainage area by subarea. An exception to the above may be granted if discharges from multiple subareas recombine in proximity to the discharge site. In this case, peak discharge in any direction may follow Management District A criteria, provided that the overall site discharge meets the management district criteria for which the discharge is located.
E.
Off-site areas. Off-site areas that drain through a proposed development site are not subject to release rate criteria when determining allowable peak runoff rates. However, on-site drainage facilities shall be designed to safely convey off-site flows through the development site.
F.
Site areas. Where the site area to be impacted by a proposed development activity differs significantly from the total site area, only the proposed impact area utilizing stormwater management measures shall be subject to the management district criteria. In other words, unimpacted areas bypassing the stormwater management facilities would not be subject to the management district criteria.
G.
"No harm" option. For any proposed development site not located in a Conditional Direct Discharge District, the applicant has the option of using a less-restrictive runoff control (including no detention) if the applicant can prove that "no harm" would be caused by discharging at a higher runoff rate than that specified by the stormwater management plan. The "no harm" option is used when an applicant can prove that the proposed conditions hydrographs can match existing conditions hydrographs and if it can be proved that the proposed conditions will not cause increases in peaks at all points downstream. Proof of "no harm" must be shown based upon the following downstream impact evaluation which shall include a downstream hydraulic capacity analysis consistent with Subsection H to determine if adequate hydraulic capacity exists. The applicant shall submit to Haverford Township this evaluation of the impacts due to increased downstream stormwater flows in the watershed.
(1)
The hydrologic regime of the site must be maintained.
(2)
The downstream impact evaluation shall include hydrologic and hydraulic calculations necessary to determine the impact of hydrograph timing modifications due to the proposed development upon a dam, highway, structure, natural point of restricted streamflow, or any stream channel section established with the concurrence of the municipality.
(3)
The evaluation shall continue downstream until the increase in flow diminishes due to additional flow from tributaries and/or stream attenuation.
(4)
The peak flow values to be used for downstream areas for the design return period storms (two-, five-, ten-, fifty-, and 100-year) shall be the values from the calibrated model for the respective watershed. These flow values can be obtained from the original Act 167 watershed stormwater management plans.
(5)
Applicant-proposed runoff controls which would generate increased peak flow rates at 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 Subsection H.
(6)
Financial distress shall not constitute grounds for the municipality to approve the use of the "no-harm" option.
(7)
Capacity improvements to conveyance facilities or obstructions may be provided as necessary to implement the "no harm" option as long as it can be demonstrated through the downstream hydraulic capacity analysis that the improvements would not create any harm downstream.
(8)
Any "no harm" justifications shall be submitted by the applicant as part of the SWM site plan submission per this article.
H.
Downstream hydraulic capacity analysis. Any downstream hydraulic capacity analysis conducted in accordance with this article shall use the following criteria for determining adequacy for accepting increased peak flow rates:
(1)
Natural or man-made channels or swales must be able to convey the increased runoff associated with a two-year return period event within their banks at velocities consistent with protection of the channels from erosion. Acceptable velocities shall be based upon criteria included in the DEP Erosion and Sediment Pollution Control Program Manual.
(2)
Natural or man-made channels or swales must be able to convey increased twenty-five-year return period runoff without creating any hazard to persons or property.
(3)
Culverts, bridges, storm sewers, or any other facilities which need to pass or convey flows from the tributary area must be designed in accordance with DEP Chapter 105 regulations (if applicable) and, at minimum, pass the increased twenty-five-year return period runoff.
(5)
Post-construction peak rates shall not exceed the existing peak rates for the respective sub-area.
I.
Alternate criteria for redevelopment sites. For redevelopment sites, one of the following minimum design parameters shall be accomplished, whichever is most appropriate for the given site conditions as determined by Haverford Township;
(1)
Meet the full requirements specified by Table 408.1 and stormwater peak rate control and management districts, § 78-39; or
(2)
Reduce the total predevelopment impervious surface on the site by at least 20% based upon a comparison of existing impervious surface to regulated impervious surface. In this case, calculations must be provided that show the peak rate has not increased.
A.
Stormwater runoff from all development sites with a drainage area of greater than five acres shall be calculated using a generally accepted calculation technique that is based on the NRCS soil cover complex method. Table 409.1 summarizes acceptable computation methods, and the method selected by the design professional shall be based on the individual limitations and suitability of each method for a particular site. Credits providing an automatic reduction in impervious area and a corresponding reduction in stormwater impacts for the reduction of design volume, peak rate, and channel protection are available for protecting existing trees as well as revegetating and reforesting as outlined in the PA DEP BMP Manual, for sites with earth disturbance of one acre or greater. No more than 25% of the volume reduction may be met through nonstructural BMP credits.
Table 409.1 Acceptable Computation Methodologies for Stormwater Management Plans | ||
|---|---|---|
Method | Developed By | Applicability |
TR-20 (or commercial computer package based on TR-20) | USDA NRCS | Applicable where use of full hydrology computer model is desirable or necessary. |
TR-55 (or commercial computer package based on TR-55) | USDA NRCS | Applicable for land development plans where limitations described in TR-55. |
HEC-1/HEC-HMS | US Army Corps of Engineers | Applicable where use of a full hydrologic computer is desirable or necessary |
PSRM | Penn State University | Applicable where use of a hydrologic model is desirable or necessary; simpler than TR-20 or HEC-1. |
Other methods | Varies | Other computation methodologies approved by the municipality and/or municipal engineer. |
HEC RAS | US Army Corp of Engineers | "No harm" option |
B.
All calculations consistent with this article using the soil cover complex method shall use the appropriate design rainfall depths for the various return period storms. Rainfall depths shall be according to NOAA Atlas 14 values consistent with a partial duration series. When stormwater calculations are performed for routing procedures or water quality functions, the duration of rainfall shall be 24 hours.
C.
The following criteria shall be used for runoff calculations:
(1)
For development sites not considered redevelopment, the ground cover used in determining the existing conditions flow rates shall be as follows:
(a)
Wooded sites shall use a ground cover of "woods in good condition." Portions of a site having more than one viable tree of a DBH of six inches or greater per 1,500 square feet shall be considered "wooded" where such trees existed within three years of application.
(b)
The undeveloped portion of the site including agriculture, bare earth and fallow ground, shall be considered as "meadow in good condition," unless the natural ground cover generates a lower curve (CN) number or Rational "c" value (i.e., woods) as listed in Tables F-2 or F-3 in Appendix F[1] of this article.
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
(2)
For development and redevelopment sites, the ground cover used in determining the existing conditions flow rates for the developed portion of the site shall be based upon actual land cover conditions.
D.
All calculations using the Rational Method shall use rainfall intensities consistent with appropriate times of concentration (duration) and storm events with rainfall intensities obtained from NOAA Atlas 14 partial duration series estimates, or the latest version of the PennDOT Drainage Manual (PDM Publication 584). Times of concentration shall be calculated based on the methodology recommended in the respective model used. Times of concentration for channel and pipe flow shall be computed using a minimum of five minutes.
E.
Runoff curve numbers (CN) for both existing and proposed conditions to be used in the soil cover complex method shall be obtained from Table F-2 in Appendix F of this article.
F.
Runoff coefficients (c) for both existing and proposed conditions for use in the rational method shall be obtained from Table F-3 in Appendix F of this article.
G.
Hydraulic computations to determine the capacity of pipes, culverts, and storm sewers shall be consistent with methods and computations contained in the Federal Highway Administration Hydraulic Design Series Number 5 (Publication No. FWHA-NHI-01-020 HDS No. 5). Hydraulic computations to determine the capacity of open channels shall be consistent with methods and computations contained in the Federal Highway Administration Hydraulic Engineering Circular Number 15 (Publication No. FHWA-BHI-05-114 HEC 15). Values for Manning's roughness coefficient (n) shall be consistent with Table F-4 in Appendix F.
H.
Outlet structures for stormwater management facilities shall be designed to meet the performance standards of this article using any generally accepted hydraulic analysis technique or method.
I.
The design of any stormwater detention facilities intended to meet the performance standards of this article shall be verified by routing the design storm hydrograph through these facilities using the storage-indication method. The design storm hydrograph shall be computed using a calculation method that produces a full hydrograph. Haverford Township may approve the use of any generally accepted full hydrograph approximation technique that shall use a total runoff volume that is consistent with the volume from a method that produces a full hydrograph.
A.
Any stormwater facility located on state highway rights-of-way shall be subject to approval by PennDOT.
B.
All wet basin designs shall incorporate biologic controls consistent with the West Nile Guidance found in Appendix H, PADEP document 363-0300-001 "Design Criteria - Wetlands Replacement/Monitoring," or contact the Pennsylvania State Cooperative Wetland Center (www.wetlands.psu.edu/) or the Penn State Cooperative Extension Office (www.extension.psu.edu/extmap.html).
C.
Any stormwater management facility (i.e., detention basin) required or regulated by this article designed to store runoff and requiring a berm or earthen embankment shall be designed to provide an emergency spillway to handle flow up to and including the 100-year proposed conditions. The height of embankment must provide a minimum 1.0 foot of freeboard above the maximum pool elevation computed when the facility functions for the 100-year proposed conditions inflow. Should any stormwater management facility require a dam safety permit under DEP Chapter 105, the facility shall be designed in accordance with Chapter 105 and meet the regulations of Chapter 105 concerning dam safety. Chapter 105 may be required to pass storms larger than the 100-year event.
D.
Any facilities that constitute water obstructions (e.g., culverts, bridges, outfalls, or stream enclosures) and any work involving wetlands governed by DEP Chapter 105 regulations (as amended or replaced from time to time by DEP) shall be designed in accordance with Chapter 105 and will require a permit from DEP.
E.
Any other drainage conveyance facility that does not fall under Chapter 105 regulations must be able to convey, without damage to the drainage structure or roadway, runoff from the twenty-five-year design storm with a minimum 1.0 foot of freeboard measured below the lowest point along the top of the roadway. Any facility that constitutes a dam as defined in DEP Chapter 105 regulations may require a permit under dam safety regulations. Any facility located within a PennDOT right-of-way must meet PennDOT minimum design standards and permit submission requirements. The larger events (fifty-year and 100-year) must also be safely conveyed in the direction of natural flow without creating additional damage to any drainage structures, nearby structures, or roadways.
F.
Any drainage conveyance facility and/or channel not governed by Chapter 105 regulations must be able to convey, without damage to the drainage structure or roadway, runoff from the twenty-five-year design storm. Conveyance facilities to or exiting from stormwater management facilities (i.e., detention basins) shall be designed to convey the design flow to or from that structure. Roadway crossings located within designated floodplain areas must be able to convey runoff from a 100-year design storm. Any facility located within a PennDOT right-of-way must meet PennDOT minimum design standards and permit submission requirements.
G.
Conveyance facilities transporting flow to or exiting from stormwater management facilities (i.e. detention basins) shall be designed to convey the 100-year frequency storm.
H.
Roadway crossings or structures located within designated floodplain areas must be able to convey runoff from a 100-year design storm consistent with FEMA Floodplain Management requirements.
I.
Adequate erosion protection shall be provided along all open channels and at all points of discharge.
J.
The design of all stormwater management facilities shall incorporate sound engineering principles and practices. Haverford Township reserves the right to disapprove any design that would result in construction in or continuation of a stormwater problem area.
A.
Except as required by Chapter 102, if a perennial or intermittent stream passes through, or a waterbody (i.e., lake, pond, wetland) is present on the site, the applicant shall create a riparian buffer extending a minimum of 100 feet, to either side of the top-of-bank of the channel, lake, or wetland.
B.
The riparian buffer shall be planted with native vegetation and maintained in a vegetated state (refer to Appendix B,[1] Pennsylvania Native Plant List, contained in the PA BMP Manual or latest guidance document from PADEP).
(1)
The following provisions also apply to riparian buffers on lots in existence at the time of adoption of this article:
(a)
If the applicable rear or side yard setback is less than 50 feet, the buffer width may be reduced to 25% of the setback or 25 feet, whichever is greater.
(2)
Permitted uses within the riparian buffer include the following, subject to municipal approval and provided that they comply with all federal, state, and local regulations:
(3)
If an existing buffer is legally prescribed (i.e., deed, covenant, easement, etc.) and it exceeds the requirements of this article, the existing buffer shall be maintained.
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
A.
The municipal engineer or his municipal designee shall inspect all phases of the installation of the permanent BMPs and/or stormwater management facilities as deemed appropriate by the municipal engineer.
B.
During any stage of the work, if the municipal engineer or his municipal designee determines that the permanent BMPs and/or stormwater management facilities are not being installed in accordance with the approved stormwater management plan, the municipality shall revoke any existing permits or other approvals and issue a cease and desist order until a revised SWM site plan is submitted and approved, as specified in this article, and until the deficiencies are corrected.
C.
A final inspection of all BMPs and/or stormwater management facilities shall be conducted by the municipal engineer or his municipal designee to confirm compliance with the approved SWM site plan prior to the issuance of any occupancy permit.
A.
The developer shall be responsible for providing as-built plans of all SWM BMPs included in the approved SWM site plan for activities involving regulated impervious surfaces 500 square feet or greater and for earth disturbances 5,000 square feet or greater. The as-built plans and all explanation of any discrepancies with the construction plans shall be submitted to the municipality within three months of the completion of construction of the SWM BMPs.
B.
As-built plans shall show the location (including latitude and longitude coordinates) and as-built conditions of all SWM BMPs and include the following information: impervious surfaces included in the approved SWM site plan; topographic contours; and existing, proposed, and built impervious surfaces shown in the as-built drawings.
C.
The as-built submission shall include a certification of completion signed by a design professional verifying that all permanent SWM BMPs have been constructed according to the approved plans and specifications.
D.
The municipality will review the as-built submission for consistency with the approved SWM site plan as well as actual conditions at the project site. After receipt of the completion certification by the municipality, the municipality may conduct a final inspection.
E.
If an NPDES Permit for Stormwater Discharges Associated with Construction Activities was required for the regulated activity, a notice of termination (NOT) approval must be obtained upon completion of construction prior to final approval of the project by the municipality.
Fees shall be established by Haverford Township to defray plan review and construction inspection costs incurred by the municipality. All fees shall be paid by the applicant at the time of SWM site plan submission. A review and inspection fee schedule shall be established by resolution of the Board of Commissioners based on the size of the regulated activity and based on the municipality's costs for reviewing SWM site plans and conducting inspections pursuant to § 78-43 Haverford Township shall periodically update the review and inspection fee schedule to ensure that review costs are adequately reimbursed.
A.
The fees required by this article shall at a minimum cover:
(1)
Administrative costs.
(2)
The review of the SWM site plan by Haverford Township and the Township Engineer.
(3)
The inspection of stormwater management facilities and drainage improvements during construction.
(4)
The site inspections.
(5)
The inspection of stormwater management facilities and drainage improvements during construction.
(6)
Attendance at meetings.
(7)
The final inspection upon completion of the stormwater management facilities and drainage improvements presented in the SWM site plan.
(8)
Any additional work required to enforce any permit provisions regulated by this article, correct violations, and assure proper completion of stipulated remedial actions.
(9)
In addition, any and all costs for the review of plans and the inspection of stormwater management facilities and drainage improvements during construction by the municipal engineer, shall be deducted from the applicant's escrow account.
A.
For SWM site plans that involve subdivision and land development, the applicant shall provide a financial guarantee to the municipality for the timely installation and proper construction of all stormwater management controls as:
B.
For other regulated activities, Haverford Township may require a financial guarantee from the applicant.
A.
No regulated earth disturbance activities within Haverford Township shall commence until approval by the municipality of a stormwater control and BMP operations and maintenance plan that describes how the permanent (e.g., post-construction) stormwater controls and BMPs will be properly operated and maintained.
B.
The Township shall make the final determination on the continuing maintenance responsibilities prior to final approval of the SWM site plan. The municipality may require a dedication of such facilities as part of the requirements for approval of the SWM site plan. Such a requirement is not an indication that the municipality will accept the facilities. The Township reserves the right to accept or reject the ownership and operating responsibility for any portion of the stormwater management controls.
C.
Facilities, areas, or structures used as SWM BMPs shall be enumerated as permanent real estate appurtenances and recorded as deed restrictions or conservation easements that run with the land.
D.
The following items shall be included in the stormwater control and BMP operations and maintenance plan:
(1)
Map(s) of the project area, in a form that meets the requirements for recording at the offices of the Recorder of Deeds of Delaware County. The contents of the maps(s) shall include, but not be limited to:
(a)
Clear identification of the location and nature of permanent stormwater controls and BMPs;
(b)
The location of the project site relative to highways, municipal boundaries, or other identifiable landmarks;
(c)
Existing and final contours at intervals of two feet, or others as appropriate;
(d)
Existing streams, lakes, ponds, or other bodies of water within the project site area;
(e)
Other physical features, including flood hazard boundaries, sinkholes, streams, existing drainage courses, and areas of natural vegetation to be preserved;
(f)
The locations of all existing and proposed utilities, sanitary sewers, and waterlines within 50 feet of property lines of the project site;
(g)
Proposed final changes to the land surface and vegetative cover, including the type and amount of impervious area that would be added;
(h)
Proposed final structures, roads, paved areas, and buildings; and
(i)
A fifteen-foot-wide access easement around all stormwater controls and BMPs that would provide ingress to and egress from a public right-of-way.
(2)
A description of how each permanent stormwater control and BMP will be operated and maintained, and the identity and contact information associated with the person(s) responsible for operations and maintenance.
(3)
The name of the project site, the name and address of the owner of the property, and the name of the individual or firm preparing the plan.
(4)
A statement, signed by the landowner, acknowledging that the stormwater controls and BMPs are fixtures that can be altered or removed only after approval by Haverford Township.
E.
The stormwater control and BMP operations and maintenance plan for the project site shall establish responsibilities for the continuing operation and maintenance of all permanent stormwater controls and BMPs, as follows:
(1)
If a plan includes structures or lots which are to be separately owned and in which streets, sewers, and other public improvements are to be dedicated to Haverford Township, stormwater controls and BMPs may also be dedicated to and maintained by the municipality;
(2)
If a plan includes operations and maintenance by a single ownership or if sewers and other public improvements are to be privately owned and maintained, then the operation and maintenance of stormwater controls and BMPs shall be the responsibility of the owner or private management entity.
A.
The municipality shall review the stormwater control and BMP operations and maintenance plan for consistency with the purposes and requirements of this article and any permits issued by DEP.
B.
The municipality shall notify the applicant in writing whether or not the stormwater control and BMP operations and maintenance plan is approved.
C.
The municipality will require an as-built plan showing all constructed stormwater controls and BMPs and an explanation of any discrepancies with the approved operations and maintenance plan.
It shall be unlawful to alter or remove any permanent stormwater control and BMP required by an approved stormwater control and BMP operations and maintenance plan or to allow the property to remain in a condition which does not conform to an approved stormwater control and BMP operations and maintenance plan.
A.
Prior to final approval of the SWM site plan, the property owner shall sign and record an operation and maintenance (O&M) agreement as drafted by the Township (in a similar form as Appendix I[1], but as may be amended by the Township) covering all stormwater control facilities which are to be privately owned. The maintenance agreement shall be transferred with transfer of ownership in perpetuity.
(1)
The owner, successor and assigns shall maintain all facilities in accordance with the approved maintenance schedule in the O&M agreement.
(2)
The owner shall convey to the Township conservation easements to assure access for periodic inspections by the Township and maintenance, as necessary.
(3)
The owner shall keep on file with the Township the name, address, and telephone number of the person or company responsible for maintenance activities; in the event of a change, new information shall be submitted by the owner to the municipality within 10 working days of the change.
[1]
Editor's Note: The appendix is included as an attachment to this chapter.
B.
The owner is responsible for operation and maintenance (O&M) of the SWM BMPs. If the owner fails to adhere to the O&M agreement, the Township may perform the services required and charge the owner appropriate fees. Nonpayment of fees may result in a lien against the property.
C.
Other items may be included in the agreement where determined necessary to guarantee the satisfactory operation and maintenance of all permanent stormwater controls and BMPs. The agreement shall be subject to the review and approval of the Township.
A.
Stormwater management easements are required for all areas used for off-site stormwater control, unless a waiver is granted by the Township.
B.
Stormwater management easements shall be provided by the applicant or property owner if necessary for access for inspections and maintenance or the preservation of stormwater runoff conveyance, infiltration, and detention areas and other stormwater controls and BMPs by persons other than the property owner. The purpose of the easement shall be specified in any agreement under § 78-51.
A.
Prior to final approval of the site's SWM site plan, the applicant shall sign and record the operation and maintenance (O&M) agreement as drafted by the Township, covering all stormwater control facilities that are to be privately owned.
B.
Other items may be included in the agreement where determined necessary to guarantee the satisfactory maintenance of all facilities. The operation and maintenance (O&M) agreement shall be subject to the review and approval of the municipal solicitor and Board of Commissioners.
A.
The owner of any land upon which permanent stormwater controls and BMPs will be placed, constructed, or implemented, as described in the stormwater control and BMP operations and maintenance plan, shall record the following documents in the Office of the Recorder of Deeds for Delaware County within 15 days of approval of the stormwater control and BMP operations and maintenance plan by the municipality:
B.
The municipality may suspend or revoke any approvals granted for the project site upon discovery of failure on the part of the owner to comply with this section.
A.
The Township shall inspect SWM BMPs, facilities, and/or structures installed under this article according to the following frequencies, at a minimum, to ensure the BMPs, facilities and/or structures continue to function as intended. Persons installing stormwater controls or BMPs shall be required to pay a specified amount to the Municipal Stormwater Control and BMP Operation and Maintenance Fund to help defray costs of periodic inspections and maintenance expenses. The amount of the deposit shall be determined as follows:
(1)
If the stormwater control or BMP is to be privately owned and maintained, the deposit shall cover the cost of periodic inspections performed by Haverford Township for a period of 10 years, as estimated by the municipal engineer. After that period of time, inspections will be performed at the expense of the municipality. The following minimum inspection frequencies are required:
(a)
Annually for the first five years.
(b)
Once every three years thereafter
(c)
During or immediately after the cessation of a twenty-five year or greater storm, as determined by the municipal engineer.
(d)
The Township Engineer may request that the landowners or landowner's designee submit an inspection report after the cessation of a ten-year or greater storm event if there is reason to believe that a BMP has sustained damage that impacts its ability to function as designed and if the BMP's failure would result in damage to downgradient properties.
(2)
If the stormwater control or BMP is to be owned and maintained by Haverford Township, the deposit shall cover the estimated costs for maintenance and inspections for 10 years. The municipal engineer will establish the estimated costs utilizing information submitted by the applicant. The following minimum inspection frequencies are required:
(3)
The above referenced inspections shall be conducted during or immediately following precipitation events or in dry weather conditions if the BMP design parameters include dewatering with a specified period of time. A written inspection report shall be created to document each inspection. The inspection report shall contain the date and time of the inspection, the individual(s) who completed the inspection, the location of the BMP, stormwater management facility or structure inspected, observations on performance, and recommendations for improving performance, if applicable.
(4)
The amount of the deposit to the fund shall be converted to present worth of the annual series values. The municipal engineer shall determine the present worth equivalents, which shall be subject to the approval of the governing body.
B.
If a stormwater control or BMP is proposed that also serves as a recreational facility (e.g., ball field or lake), Haverford Township may reduce or waive the amount of the maintenance fund deposit based upon the value of the land for public recreational purpose.
C.
If at some future time a stormwater control or BMP (whether publicly or privately owned) is eliminated due to the installation of storm sewers or other storage facility, the unused portion of the maintenance fund deposit will be applied to the cost of abandoning the facility and connecting to the storm sewer system or other facility. Any amount of the deposit remaining after the costs of abandonment are paid will be returned to the depositor.
D.
If stormwater controls or BMPs are accepted by Haverford Township for dedication, the municipality may require persons installing stormwater controls or BMPs to pay a specified amount to the Municipal Stormwater Control and BMP Operation and Maintenance Fund to help defray costs of operations and maintenance activities. The amount may be determined as follows:
E.
If a stormwater control or BMP is proposed that also serves as a recreational facility (e.g., ball field or lake), Haverford Township may adjust the amount due accordingly.
F.
Haverford Township shall require applicants to pay a fee to the Municipal Stormwater Control and BMP Operation and Maintenance Fund to cover long-term maintenance of stormwater controls and BMPs.
G.
Haverford Township may require applicants to pay a fee to the Municipal Stormwater Control and BMP Operation and Maintenance Fund to cover inspections, long term maintenance of stormwater BMPs and conveyances, and stormwater related problems which may arise from the land development and earth disturbance.
A.
Any drain or conveyance, whether on the surface or subsurface, that allows any nonstormwater discharge including sewage, process wastewater, and wash water to enter the Township's separate storm sewer system, riparian buffers, wetlands, or other waters of this Commonwealth, and any connections to the storm drain system from indoor drains and sinks, is prohibited.
B.
No person in Haverford Township shall allow, or cause to allow, stormwater discharges into a regulated small MS4, or discharges into waters of this Commonwealth, which are not composed entirely of stormwater, except as provided in Subsection C below, and discharges authorized under a state or federal permit.
C.
The following discharges are authorized unless they are determined to be significant contributors to pollution to a regulated small MS4 or to the waters of this Commonwealth:
(1)
Discharges from firefighting activities.
(2)
Discharges from potable water sources including water line flushing and fire hydrant flushing, if such discharges do not contain detectable concentrations of total residual chlorine (TRC).
(3)
Noncontaminated irrigation drainage water.
(4)
Routine external building washdown (which does not use detergents or other compounds).
(5)
Noncontaminated HVAC condensation and water from geothermal systems.
(6)
Residential (i.e., not commercial) vehicle wash water where cleaning agents are not utilized.
(7)
Springs and water from crawl space pumps.
(8)
Uncontaminated water from foundation or from footing drains.
(9)
Flows from riparian habitats and wetlands.
(10)
Lawn watering.
(11)
Pavement washwaters 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.
(12)
Uncontaminated groundwater
(13)
Noncontaminated hydrostatic test water discharges if such discharges do not contain detectable concentrations of TRC.
(14)
Diverted stream flows.
D.
In the event that the municipality determines that any of the discharges identified in Subsection C significantly contribute pollutants to a regulated small MS4 or to the waters of this Commonwealth, or is so notified by DEP, the Township will notify the responsible person(s) to cease the discharge.
E.
Upon notice provided by the Township under § 78-56D, the discharger will have a reasonable time, as determined by the Township, to cease the discharge consistent with the degree of pollution caused by the discharge.
F.
Nothing in this section shall affect a discharger's responsibilities under state law.
A.
Roof drains and sump pumps shall not be connected to sanitary sewers.
B.
Roof drains and sump pumps shall not be connected to streets, storm sewers, or roadside ditches except on a case by case basis as determined by the Township.
C.
Roof drains and sump pumps shall discharge to infiltration areas or vegetative BMPs to the maximum extent practicable where advantageous to do so.
The following connections are prohibited, except as provided in § 78-56C above:
A.
Any drain or conveyance, whether on the surface or subsurface, which allows any nonstormwater discharge including sewage, process wastewater, and wash water, to enter the separate storm sewer system, and any connections to the storm drain system from indoor drains and sinks.
B.
Any drain or conveyance connected 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 Haverford Township.
C.
Any drain or conveyance that delivers nonstormwater discharges directly into wetlands, riparian buffers, or other waters of the commonwealth is prohibited.
A.
No person shall modify, remove, fill, landscape, or alter any existing stormwater control or BMP unless it is part of an approved maintenance program without the written approval of Haverford Township.
B.
No person shall place any structure, fill, landscaping, or vegetation into a stormwater control or BMP or within a drainage easement which would limit or alter the functioning of the stormwater control or BMP without the written approval of Haverford Township.
A.
Upon presentation of proper credentials, the Township or its designated agent may enter at reasonable times upon any property within the municipality to inspect the condition, implementation, or operation and maintenance of all erosion and sediment controls and permanent stormwater BMPs, conveyances, or other stormwater management facilities both during and after the completion of the regulated activity, or for compliance with any requirement of the stormwater structures and facilities in regard to any aspect regulated by this article.
B.
Stormwater control and BMP owners and operators shall allow persons working on behalf of Haverford Township ready access to all parts of the premises for the purposes of determining compliance with this article.
C.
Persons working on behalf of Haverford Township shall have the right to temporarily locate on any stormwater control or BMP in the municipality such devices as are necessary to conduct monitoring and/or sampling of the discharges from such stormwater control or BMP.
D.
Unreasonable delays in allowing the municipality access to a stormwater control or BMP is a violation of this article.
E.
If the property owner or representative does not grant access to the municipality within 24 hours of the notification, it will be a violation of this article.
A.
Whenever Haverford Township finds that a person has violated a prohibition or failed to meet a requirement of this article, the municipality may order compliance by written notice to the responsible person. Such notice may, without limitation, require the following remedies:
(1)
Performance of monitoring, analyses, and reporting;
(2)
Elimination of prohibited connections or discharges;
(3)
Cessation of any violating discharges, practices, or operations;
(4)
Abatement or remediation of stormwater pollution or contamination hazards and the restoration of any affected property;
(5)
Payment of a fine to cover administrative and remediation costs;
(6)
Implementation of stormwater controls and BMPs; and
(7)
Operation and maintenance of stormwater controls and BMPs.
B.
Such notification shall set forth the nature of the violation(s) and establish a time limit for correction of these violations(s). Said notice may further advise that, if applicable, should the violator fail to take the required action within the established deadline, the work will be done by Haverford Township or designee, and the expense thereof shall be charged to the violator.
C.
Failure to comply within the time specified shall also subject such person to the penalty provisions of this article. All such penalties shall be deemed cumulative and shall not prevent the municipality from pursuing any and all other remedies available in law or equity.
A.
Any building, land development, or other permit or approval issued by the Township pursuant to this article may be suspended or revoked for:
(1)
Noncompliance with or failure to implement any provision of the permit.
(2)
A violation of any provision of this article or any other applicable law, ordinance, rule, or regulation relating to the regulated activity.
(3)
The creation of any condition or the commission of any act during construction or development which constitutes or creates a hazard, nuisance, pollution, or endangers the life or property of others.
B.
A suspended permit or approval may be reinstated by the Municipality when:
C.
A permit or approval that has been revoked by the Township cannot be reinstated. The applicant may apply for a new approval under the provisions of this article.
D.
Prior to revocation or suspension of a permit and at the request of the applicant, the governing body shall schedule a hearing to discuss the noncompliance if there is no immediate danger to life, public health, or property. The expense of a hearing shall be the applicant's responsibility.
A.
Any person violating the provisions of this article shall be guilty of a misdemeanor and upon conviction shall be subject to a fine of not more than $1,000 for each violation, recoverable with costs, or imprisonment of not more than 90 days, or both. Each day that the violation continues shall be a separate offense.
B.
In addition, the Township, through its solicitor, may institute injunctive, mandamus, or any other appropriate action or proceeding at law or in equity for the enforcement of this article. Any court of competent jurisdiction shall have the right to issue restraining orders, temporary or permanent injunctions, mandamus, or other appropriate forms of remedy or relief.
In the event that a person fails to comply with the requirements of this article or fails to conform to the requirements of any permit issued hereunder, the Township shall provide written notification of the violation. Such notification shall state the nature of the violation(s) and establish a time limit for correction of these violation(s). Failure to comply within the time specified shall subject such person to the penalty provisions of this article. All such penalties shall be deemed cumulative and shall not prevent the Township from pursuing any and all remedies. It shall be the responsibility of the owner of the real property on which any regulated activity is proposed to occur, is occurring, or has occurred to comply with the terms and conditions of this article.
The Board of Commissioners is hereby authorized and directed to enforce all of the provisions of this article. All inspections regarding compliance with the SWM site plan shall be the responsibility of the Township Engineer or other qualified persons designated by the Board of Commissioners.
A.
A set of design plans approved by the Township shall be on file at the site throughout the duration of the construction activity. Periodic inspections may be made by the Township or designee during construction.
B.
It shall be unlawful for any person, firm, or corporation to undertake any regulated activity under § 78-17 on any property except as provided for in the approved SWM site plan and pursuant to the requirements of this article. It shall be unlawful to alter or remove any control structure required by the SWM site plan pursuant to this article or to allow the property to remain in a condition which does not conform to the approved SWM site plan.
C.
At the completion of the project and as a prerequisite for the release of the performance guarantee, the owner or his representatives shall:
D.
After receipt of the certification by Haverford Township, a final inspection shall be conducted by the municipal engineer or designated representative to certify compliance with this article.
A.
Any person aggrieved by any action of the Township or its designee may appeal to the Board of Commissioners of Haverford Township within 30 days of that action.
B.
Any person aggrieved by any decision of the Board of Commissioners of Haverford Township may appeal to the County Court of Common Pleas in the County where the activity has taken place within 30 days of the municipal decision.