The public improvements required by this article shall be installed to the standards as identified in the following sections and the West Deer Township Construction Standards.[1] Prior to the start of installation of any and all improvements, the developer or his or her contractor shall notify the Township at least 48 hours in advance in order to schedule the inspection of such installation. The Township Engineer shall inspect all work before backfilling, before spreading subbase or applying base course to any street or before covering any other structures that are part of the improvements and may order corrections be made to bring it to compliance with the final approved plans. The Township shall reinspect the work to assure that corrections have been made before ordering the contractor proceed. When the installation of all required improvements have been completed, the developer shall follow the procedure as identified in Article V of this chapter.
A. 
General standards. The standards outlined in this article and depicted in exhibits referenced herein, shall be applied by the Township staff, the Planing Commission and the Board of Supervisors in evaluating plans for proposed subdivisions and land developments. The standards outlined herein and in the West Deer Township Construction Standards shall be considered minimum standards, and the Planning Commission or Board of Supervisors may request more restrictive standards where the health, safety and welfare of Township residents is a concern.
B. 
Natural and historic features. Every measure shall be taken to ensure, insofar as possible, the preservation of natural amenities and historic, natural and man-made features, areas and structures deemed worthy of such preservation by the Planning Commission and Board of Supervisors, and public access to such features where appropriate.
C. 
Coordination of development. The design of proposed subdivisions and land developments shall be compatible in scale and building materials with existing nearby development and physiography so that the area may be developed harmoniously.
D. 
Conformance. The design of proposed subdivisions and land developments shall conform to the standards outlined in this article and with the standard engineering details included in the West Deer Township Construction Standards. In addition, all proposed subdivisions and land developments shall conform to the community goals and objectives of the West Deer Township Comprehensive Development Plan, to all applicable land use regulations in effect at the time of final approval, to the Official Map and to the regulations of any federal or state agency with jurisdiction over any aspect of the proposal being reviewed.
E. 
Description. All streets or roads proposed to be dedicated for public use shall be designed and constructed according to the requirements of Pennsylvania Department of Transportation Publication 408, latest revision, unless otherwise noted, and the shape, width, depth and geometry to conform to the West Deer Township Construction Standards and to a horizontal and vertical alignment as approved by the Township Engineer.
F. 
Cartway and right-of-way. All streets or roads shall have a minimum fifty-foot-wide right-of-way. All cartways shall be paved in accordance with the standards set forth in Table A,[2] as shown in Drawing #1 of the Construction Standards, except private streets or roads as defined in Table A, and as provided for in § 185-26G. The right-of-way for culs-de-sac shall be a minimum of 100 feet in diameter and shall have a minimum eighty-foot paved diameter.
[1]
Editor's Note: The West Deer Township Construction Standards are on file in the Township offices.
A. 
Cul-de-sac streets. Cul-de-sac streets may not be longer than 1,500 feet in length, and shall be designed as specified in Exhibit 6.[1]
[1]
Editor's Note: Exhibits #1 through #6 are included in Appendix A as an attachment to this chapter.
B. 
Lot size. All lots shall conform to the West Deer Township Zoning Ordinance in area, minimum width at building line and configuration as outlined herein.
C. 
Access. Every lot shall abut a public or private street with a minimum frontage of 50 feet, designed and built to the standards in Table A[2] and this article.
D. 
Through lots. Double frontage lots shall not be permitted, except that where frontage occurs along limited access or arterial highways, lots may face on an interior street and back on such thoroughfares to which direct access shall not be permitted.
E. 
Lot lines. Lot lines shall be approximately at right angles or radial to the street lines.
F. 
Corner lots. Corner lots shall be proportionately larger than other lots in order to meet required building setbacks from both streets.
G. 
Building setback lines. The building setback lines must conform to the applicable Zoning Ordinance provisions for the district in which the subdivision is proposed.
H. 
Solar consideration. To help provide access to solar concerns, developers shall be sensitive to solar planning which shall be considered a purpose of this chapter. Portions of this chapter (lot access, sidewalks, screening, street trees) may be recommended for modification by the Planning Commission and approved by the Board of Supervisors in consideration of the following definitions, where appropriate:
SOLAR ENERGY
Radiant energy received either directly or indirectly from the sun at wavelengths suitable for conversion into thermo, chemical or electric energy.
SOLAR SKYSPACE
The space between a solar collector (passive or active) and the sun which must remain unobstructed in order to permit efficient utilization of the solar energy system.
SOLAR SKYSPACE EASEMENT
A right expressed as an easement covenant, condition or other property interest, in any deed or other instrument executed by or on behalf of any landlord which protects the solar skyspace of an actual, proposed or designated solar collector at a described location by prohibiting or limiting activities or land uses that interfere with access to solar energy.
UNDERGROUND STRUCTURE
Any completed building that was designed to be built partially or wholly underground; a completed structure which was not intended to serve as a substructure or foundation for a building. Four types of underground structures are recognized:
(1) 
Elevational: wall exposed.
(2) 
Atrium or courtyard.
(3) 
Penetrational: wall openings.
(4) 
Chamber.
A. 
Proposed streets shall be planned with regard to topographic conditions (diagonally across contours where slopes are in excess of 15%); public safety and convenience in terms of vehicular and pedestrian movements, maintenance and fire protection; probable traffic volumes; and existing and proposed uses of land on abutting properties.
B. 
The proposed street system shall be extensions of existing or recorded streets at the same width, but in no case at less than the required minimum width.
C. 
Where, in the opinion of the Township Planning Commission, it is desirable to provide for street access to adjoining property, streets shall be extended by right-of-way dedication to the boundary of such property. Where the extended cartway is wider than the existing cartway, a tapered transition area shall be provided.
D. 
New minor streets shall be so designed as to discourage through traffic, but the developer shall give adequate consideration to provisions for the extension and continuation of collector streets into and from adjoining properties.
E. 
Where an existing Township street of inadequate width traverses or abuts the subdivision or land development, the entire right-of-way, measured from the center line of the existing cartway, shall be provided in accordance with the standards of this chapter.
F. 
Where the subdivision or land development abuts or is traversed by an existing state street of inadequate width or alignment, any additional right-of-way necessary to correct such in accordance with the standards of this chapter or known highway plans shall be reserved, but need not be offered for dedication.
G. 
Private streets, either proposed or existing, shall not be approved for public dedication, construction or maintenance until the location, design and construction of any such street is in compliance with all applicable requirements of this chapter. Private streets may be authorized to permit limited subdivision of lots subject to the following requirements:
(1) 
A maximum of four lots, plus a residual parcel containing one existing residential structure, may be approved for access on a private street.
(2) 
The private street right-of-way shall be a minimum of 50 feet, except as otherwise indicated.
(3) 
The street shall be installed to provide the required minimum width with a mud-free cartway in accordance with the design standards in Table A,[1] which is adequate to enable all-weather passage of vehicles.
(4) 
Sales agreements for all lots abutting the private road shall include notification to purchasers of the nonliability of the Township for road maintenance. In addition, a certificate of the nonliability of the Township shall be inscribed on the plan when submitted for municipal approvals.
(5) 
All costs associated with the design, construction, maintenance or any other expense involving said street improvements shall be assumed by private sources with no cost to the Township prior to final acceptance for dedication by the Township Supervisors.
(6) 
A temporary turnaround for maintenance and emergency vehicles shall be provided where future street or roadway extensions are designed to occur, said turnaround shall have a minimum eighty-foot diameter curb to curb and exhibit a mud-free condition.
(7) 
A private maintenance agreement form provided by the Township shall be signed and recorded prior to consideration of roadway acceptance.
H. 
Whenever the proposed subdivision or land development contains or is adjacent to an arterial highway, the Board of Supervisors may recommend that provision be made for a marginal access street. The Board may also recommend rear service alleys, reverse frontage lots or such other configurations which will provide increased protection for abutting properties, reduce the number of intersections with major streets and separate local and through traffic.
I. 
Where the lots in a subdivision are large enough for resubdivision or where a portion of the tract is not subdivided, the minimum required right-of-way to these areas shall be provided.
J. 
Proposed streets which are aligned with existing streets shall bear the name of the existing street.
K. 
Dead-end streets shall be prohibited, except when designed and constructed as permanent cul-de-sac streets or as stubs to permit future street extension into adjoining tracts (in such cases, a temporary turnaround having at least an asphalt surface and an outside diameter of 80 feet shall be provided).
L. 
Intersections involving the crossing of more than two streets shall be prohibited. Right angle intersections shall be used whenever practical, but in no case shall the angle of intersection be less than 60°. Street offsets of less than 125 feet shall not be permitted.
M. 
The shoulders of all streets and roads dedicated for public use shall be graded to the full width of the right-of-way and provisions shall be made for protection of slopes beyond the right-of-way.
N. 
Minimum and maximum grades shall be provided on all streets in accordance with the design standards specified in Table A,[2] unless a modification is granted. Grades shall be measured along the center of the street. Vertical curves shall be used in changes of grade exceeding 1% and should be designed in accordance with the Design Standards specified in Table A. The grade of actual intersections shall not exceed 3% on approaches which will be "stop" controlled.
O. 
Minimum widths of rights-of-way and minimum widths of paving shall be provided in accordance with the Design Standards specified in Table A. All streets or roads dedicated for public use shall be paved in accordance with Drawing #1 in the West Deer Township Construction Standards.
P. 
Additional right-of-way widths and paved cartway widths may be requested by the Township where necessary for public safety and convenience, for parking in commercial and residential areas and where additional width is necessary on existing roads which do not comply with current standards; however, the approval of the plan shall not be conditioned upon dedication of the additional right-of-way.
Q. 
A temporary turnaround may be required where a road is constructed to an adjoining property line or where street construction is proposed to be phased within a development. The right-of-way width required for a temporary turnaround shall be a minimum of 50 feet and the outer paving radius of the temporary turnaround shall be 20 feet.
R. 
No fence, hedges, shrubbery, walls, planting (other than trees and grass) or similar obstructions shall be located within the right-of-way of any street or road dedicated for public use, and no such obstruction shall obscure visibility at any intersection. A clear sight triangle, as defined by this chapter and illustrated in Exhibit #2,[3] shall be maintained free of any obstructions at intersections. The sides of the clear sight triangle shall be measured along the center line of the intersecting streets and shall meet the minimum standards specified in Table B.[4]
[3]
Editor's Note: Exhibits #1 through #6 are included in Appendix A as an attachment to this chapter.
[4]
Editor's Note: Intersection Design Standards Table B is included as an attachment to this chapter.
B. 
Intersection Design Standards Table B is included as an attachment to this chapter.
C. 
Description. All streets or roads proposed to be dedicated for public use shall be designed and constructed according to the requirements presented in the Pennsylvania Department of Transportation Publication 408 and the West Deer Township Construction Standards[1] and the shape, width, depth and geometry shall conform to the street paving detail, Drawing #1 in the West Deer Township Construction Standards, and to a horizontal and vertical alignment as approved by the Township Engineer.
[1]
Editor's Note: The West Deer Township Construction Standards are on file in the Township offices.
D. 
Cartway and right-of-way. All streets or roads shall have a minimum fifty-foot-wide right-of-way. All cartways shall be paved in accordance with the standards set forth in Table A,[2] and as shown in the West Deer Township Construction Standards, except private streets as defined in Table A and § 185-26G. The right-of-way for culs-de-sac shall be a minimum of 100 feet in diameter and shall a minimum ninety-foot paved diameter.
E. 
Construction.
(1) 
Excavation and grading.
(a) 
The excavation and grading required to construct the road shall be constructed to the horizontal and vertical alignment, as approved by the Township Engineer. For approval, roadway design shall be presented on plan and profile drawings prepared at a minimum scale of one inch equals 50 feet horizontal to one inch equals 10 feet vertical with cross-section at fifty-foot centers at appropriate scale. Cross-section shall be a minimum one-hundred-foot-wide or show the entire extent of cut/fill proposed.
(b) 
All excavation and grading operations shall be performed under the direct supervision of a registered professional soils engineer. At completion of the work, the soils engineer shall provide a written sealed certification that all cuts/fills as constructed are stable and suited to their design intent.
(c) 
When filling operations are required, all topsoil shall be removed and the surface scarified in order to assure a good bond between the filled ground and virgin ground. Where the lateral slope upon which a fill is to be made is deemed too steep for scarifying to make bond (slopes three horizontal to one vertical or steeper), the virgin ground shall be benched as shown on Exhibit #3[3] and the fill placed upon the benches. Drainage for any springs, wet areas, existing streams or wet weather gullies encountered while preparing for filling operations can be commenced. Toe drains or underdrains shall be constructed as required by the Township Engineer.
[3]
Editor's Note: Exhibits #1 through #6 are included in Appendix A as an attachment to this chapter.
(d) 
Fills shall be built up in six-inch lifts of suitable materials, each lift being well-compacted with an approved sheep's-foot ten-ton roller and well-crowned and drained in order to prevent soaking and spongy areas.
(e) 
All fills or cuts shall carry a minimum side slope of two feet horizontal to one foot vertical.
(f) 
Built up, well-rolled berms shall be constructed along each edge of the paving using suitable and approved material. The berm shall be constructed before the curb or base is constructed and simultaneously with the fine grading of the subgrade.
(g) 
The subgrade must be well-rolled with approved three-wheel, minimum ten-ton roller, crowned in conformance with finished surface crown and shall be perfectly smooth, free of spongy areas and well-drained with approved subgrade drains and/or bleeders, the bleeders draining into approved dry wells (constructed at a minimum distance of three feet from the edge of paving), lateral drains, storm sewers or drop inlets. The flow lines of all dry wells, lateral drains, storm sewers and drop inlets shall be a minimum 16 inches below the lowest part of the subgrade. All drainage must be constructed and in operation before any fine grading, berm construction or filling is commenced.
(2) 
Subbase and base. The subbase and base shall consist of 12 1/2 inches of combined aggregate subbase and ID-2 bituminous concrete base course as presented on Drawing #1 of the Construction Standards.[4] For single-family residential subdivisions, a minimum of 10 AADT counts per lot per day shall be used to compute the annual average daily traffic (AADT) for the site to be developed. In addition, an allowance shall be made for all undeveloped land that can gain access through the proposed roadway. All roads proposed to serve all nonresidential uses, and which are to be publicly dedicated, shall be designed to serve an AADT as defined by a traffic study prepared by a consultant acceptable to the Township. Said traffic study shall be approved by the Township Engineer.
[4]
Editor's Note: The West Deer Township Construction Standards are on file in the Township offices.
(3) 
Curbing.
(a) 
A compacted twelve-inch-wide ID-2 bituminous wedge-type curb shall be installed on each side of the cartway. The base course portion (first stage) of the twelve-inch wedge-type curb shall be installed with the first layer of wearing course.
(b) 
The bituminous wedge curbing shall be machine spread and machine rolled. The dimensions, size and shape shall be in accordance with Drawing #1 of the Construction Standards. After placement, the wedge curb shall be properly barricaded and protected from any traffic or vehicles of any kind until it has thoroughly set up and all voids on the grass plot side have been completely backfilled, and the backfill being placed with proper and approved tamping equipment in maximum four-inch layers. No traffic or vehicles of any kind will be permitted to pass over this curb except through driveway approaches.
(4) 
Bituminous wearing course.
(a) 
The surface wearing course shall be 1 1/2 inches thick and shall be compacted bituminous surface course ID-2 installed in accordance with Section 420 of PennDOT's publication 408.
(b) 
Seal all joints as required or directed, in accordance with Section 469.
(5) 
Materials/plant. All bituminous material must be prepared in a plant that has been approved by the Pennsylvania Department of Highways for the manufacture of the material specified. Certification of compliance of all materials used to pave the streets shall be provided to the Township by the plant.
(6) 
Testing finished surface. For the purpose of testing the finished surface, a sixteen-foot straight edge shall be used, except that a ten-foot straight edge may be used on vertical curves. The straight-edge shall be held in successive position parallel to the road center line in contact with surface, and the whole area checked from one side to the other as necessary. Advance along the pavement shall be in successive stages of not more than 1/2 the length of the straight edge. Any irregularities which may vary more than 1/4 inch shall be corrected. Irregularities which may develop before the completion of rolling shall be remedied by loosening the surface mixture and removing or adding material as may be required. Should any irregularities or defects remain after the final compression, the surface course shall promptly be removed and sufficient new material laid to form a true and even surface. All minor surface projections, joints and minor honeycombed surfaces shall be ironed smooth to grade, as may be directed.
(7) 
Calendar construction limitations. Road construction such as filling, berming, subgrade, fine-grade construction, base construction or surface construction shall not be commenced before May 15 and must be completed before October 15 of the same year, unless permission is granted by the Board of Supervisors. It is assumed that the weather conditions between these dates will be ideal for road construction; however, if adverse weather conditions occur between these dates the contractor or builder must abide by the judgment of the Township Supervisors, their agents or assigns, in regard to permissible construction weather conditions.
(8) 
Special requirements.
(a) 
The contractor or builder shall be required to provide to the Township an eighteen-month maintenance bond commencing on the date of acceptance of the road by the Township in an amount equal to 15% of the actual cost of installation of the roadway.
(b) 
If it is necessary that the contractor must exceed a weight limit of eight tons (which will be in effect simultaneously with the date of acceptance), he or she will be required to give the Township an additional eighteen-month maintenance bond in an amount specified by the Township Engineer commencing on the date that the violation of the weight limit ceases. In no event shall the contractor violate the weight limit without the expressed approval of the Township and, if approved, not before the aforementioned maintenance bond has been obtained and is in effect.
(c) 
In order to assure the Township that the road is being paved in the center of the right-of-way and in accordance with all grades that have been approved, the contractor, developer and/or road builder must present an affidavit signed by a registered professional engineer or a registered surveyor, each registered to practice his or her profession in the Commonwealth of Pennsylvania, that he or her (surveyor/engineer) has established the recorded and/or legal right-of-way on the ground by a survey on the ground and has set construction stakes to the desired construction offset distance at points along the road not exceeding fifty-foot intervals and has established reference elevation on said stakes to effect the construction of the road in accordance with all plans that have been previously approved.
(d) 
After all road construction has been completed and all right-of-way grading has been completed, the developer and/or contractor shall install concrete monuments which comply with § 185-35 of this chapter and as shown in Exhibit 4,[5] at all intersections and points of curvature in order to amply mark the right-of-way before the construction of the road can be considered as complete and fully prepared for the Township to accept the maintenance responsibilities.
[5]
Editor's Note: Exhibits #1 through #6 are included in Appendix A as an attachment to this chapter.
(e) 
An escrow bond of $150 per concrete monument must be delivered to the Township. When monuments are placed, approved by the developer's engineer and inspected by the Township Engineer, then the escrow bond will be released to the developer.
(9) 
Effective date. This chapter shall become effective on the date of enactment and shall apply to all roads and streets in plans of lots hereafter submitted to and approved by the Township.
Sidewalks at least four feet in width, constructed of four-thousand-pound portland cement concrete at least four inches thick and underlain by four inches crushed stone shall be installed as follows:
A. 
In subdivisions which have a typical lot width of 80 feet or less at the building line.
B. 
In all subdivisions or developments involving dwellings of a type other than single-family detached.
C. 
Where the continuation of existing sidewalks would be desirable.
D. 
To provide access to community facilities and elsewhere as recommended by the Planning Commission and approved by the Board of Supervisors.
E. 
Sidewalks shall be located within the street right-of-way, preferably one foot from the property line, and in all cases shall be separated from a cartway by a planting strip.
F. 
Sidewalks shall be constructed so as to be accessible to the handicapped.
G. 
Maintenance shall be the responsibility of the adjacent property owner.
H. 
In accordance with Table A[1] and Exhibit #7 of the Construction Standards.[2]
[2]
Editor's Note: The West Deer Township Construction Standards are on file in the Township offices.
Street name signs shall be placed at all intersections and a streetlighting system shall be installed in developments involving multifamily dwellings and elsewhere as required by the municipality. The design and location of signs and light fixtures shall be as approved by the Township Supervisors.
A. 
The subdivision or land development shall be provided with a complete public water distribution and supply system which shall be connected to a Township water supply, or with a private water distribution and supply system approved by the engineer of the water utility company with jurisdiction, if applicable, and the Pennsylvania Department of Environmental Protection, with satisfactory provision for the maintenance thereof, except that when such Township or private water supply system is not available, the land development of each lot in the subdivision shall be provided with an individual water distribution and supply system in accordance with the minimum standards of the Pennsylvania Department of Environmental Protection.
B. 
Fire hydrants shall be installed as an integral part of any common water distribution and supply system, placed not greater than 1,200 feet apart. Said water distribution system shall have sufficient residual pressure for fire protection, as required by the Pennsylvania Department of Environmental Protection.
C. 
The plans for the installation of the mains of a water distribution and supply system shall be prepared with the cooperation of the applicable public water authority, and approved by its engineer. A statement of approval from the engineer of the public water authority shall be submitted to the Board of Supervisors. Upon the completion of the public water distribution and supply system, one copy each of the plans for such system shall be filed with the Board of Supervisors. The plan shall be reviewed and approved by the Department of Environmental Protection.
D. 
Individual on-lot water supply facilities shall not be deemed part of the required improvements of this chapter.
A. 
The method of waste disposal shall be as approved by the Board of Supervisors, giving consideration to the following order of preference:
(1) 
Connection to a public sanitary sewer system, to be in accordance with the requirements of the Department of Environmental Protection.
(2) 
Provision by the developer of a complete private sanitary sewer collection system using a treatment plant, to be licensed by the Department of Environmental Protection.
(3) 
Sewage disposal on individual lots where conditions are satisfactory to meet the on-lot sewage requirements of Act 537, known as the "Pennsylvania Sewage Facilities Act."[1]
[1]
Editor's Note: See 35 P.S. § 750.1 et seq.
B. 
The judgment of the Board of Supervisors as to the method of waste disposal to be used will be made after study and review of a sewerage feasibility report submitted by the developer. The submission of the sewerage feasibility report is required. It must be completed by a registered professional engineer.
C. 
When the subdivision or land development is to be provided with a complete public sanitary sewer collection system to be connected to a public sanitary sewer system, a statement of approval from the engineer of the sewerage system authority to which it will be connected shall be submitted to the Board of Supervisors.
D. 
When a complete private sanitary sewer collection system using a treatment plant is to be provided, a copy of all required permits and licenses shall be submitted to the Board of Supervisors following the Pennsylvania Department of Environmental Protection approval of the proposed facilities. Adequate provision for the maintenance and yearly inspection of such plant shall be furnished to the municipality in which the subdivision or land development is located.
E. 
In subdivisions or land developments where neither connection to a public sewerage system nor a complete sanitary sewer system is required, sewage disposal shall be provided consisting of septic tanks and absorption fields, or any package disposal system or treatment plant permitted and licensed by the Department of Environmental Protection, in accordance with the Pennsylvania Sewage Facilities Act 537.
F. 
When on-lot sewage disposal is to be provided, the developer shall furnish a certificate as to the adequacy of the soils for such on the basis of percolation tests conducted in accordance with the Department of Environmental Protection.
A. 
Storm sewers. Description. Each land subdivision and/or land development, whether residential, commercial or industrial in nature or use, shall provide and implement a water drainage plan and stormwater management plan so as to prevent any damage or injury to health, safety or property from stormwater runoff or groundwater. The water drainage plan shall be in accordance with this article and Article VIII and shall be reviewed by the Allegheny County Planning Department and approved by the Township. All storm drainage systems shall discharge to an existing storm sewer, an established stream channel approved by the Township Engineer or an approved level spreading or infiltration structure. All discharges not connected directly to a storm sewer shall be provided with approved erosion control facilities. All facilities must be approved by the Township Engineer.
(1) 
All drainage management measures shall include such actions as are required to manage the quantity, velocity and direction of resulting ground and/or stormwater runoff in a manner which protects health and property from injury.
(2) 
Natural runoff flow characteristics shall be maintained either by augmenting natural infiltration processes or by physically controlling the release of development related stormwater flow increases through structural means.
(3) 
Positive drainage is required in all areas of development. The stormwater system shall be planned and designed to direct stormwater runoff away from all public roads, structures, buildings and development areas. The stormwater drainage system shall provide drainage facilities at all points along public streets and sidewalks, including other access and circulation systems.
(4) 
Underdrainage shall be provided in all areas where springs, wet weather springs or poor soil drainage conditions exist or result from the development. During construction of any improvement, if springs or any other poor drainage conditions are encountered, or when construction of any improvement has or will alter the natural groundwater flow, the Township shall be notified. Underdrainage shall be provided by the owner/developer, as directed by the Township, to correct said poor drainage condition.
(5) 
The stormwater system, including downspouting and other forms of raingear which are utilized upon any structure within the land subdivision and/or land development, and the underdrainage system shall be designed to convey, contain, store, absorb, and/or use the surface or underground waters without damage to life or property and to minimize disruption of land usage.
(6) 
All on-lot storm drains (downspouts, area drains, foundation drains, etc.) shall include all pipe required to convey runoff water directly to storm sewers or the stormwater management facility, in accordance with Exhibit #5[1] of this chapter. No runoff water shall be allowed to discharge onto the street/road.
[1]
Editor's Note: Exhibit #1 through #6 are included in Appendix A as an attachment to this chapter.
(7) 
To the maximum extent possible, the stormwater drainage system and underground drainage system shall be designed to convey stormwater runoff through a conveyance system directly to a natural watercourse and prevent the discharge of stormwater or underground water onto adjacent facilities or properties.
(8) 
Natural drainage routing shall be preserved where feasible. No discharge of on-site stormwater or underground water runoff into a natural drainage routing shall be permitted when such discharge will damage adjacent or downstream property.
(9) 
No stormwater drainage system or underground drainage system shall be permitted to discharge into any sanitary sewer system.
(10) 
The storm sewer system shall be designed to intercept and convey the peak rate of runoff from the twenty-five-year return storm.
(11) 
Stormwater runoff and design calculations to meet this requirement shall be submitted to the Township for approval prior to preliminary plan approval. Hydraulic computation presenting invert elevations, pipe size, "n" capacity, velocity, hydraulic and energy grade lines shall be submitted.
(12) 
Upon Township request, stormwater runoff calculations shall be made available for the outlet and inlet sides of all stormwater drainage and storage facilities and structures; at points in a public street with a change of grade; or where water from a proposed structure, facility or vehicular way is to enter an existing public street, existing storm sewer, existing drainage ditch or existing stormwater storage facility.
(13) 
Additional analysis, calculations and design criteria may be required for both the on-site and off-site stormwater systems where it has been determined by the Township that further study is necessary.
(14) 
The stormwater drainage system for the subdivision and/or land development and, where required, the underdrainage system for a subdivision and/or land development shall be designed for compatibility with the watershed stormwater management system and any West Deer Township or adjacent municipality's planned change to the system.
(a) 
The design shall anticipate and provide for effects of all tributary area and upstream development.
(b) 
The design shall anticipate and provide for impact(s) on downstream flow conditions and water quality.
(c) 
Off-site stormwater drainage and underdrainage facilities and improvement shall be provided by the applicant/owner of the proposed land subdivision and/or land development where needed and where requested by the Township.
(d) 
Where required, the Pennsylvania Department of Environmental Protection's approval, including permits as required, shall be obtained by the applicant/owner of the land subdivision and/or land development and evidence of the same provided to the Township.
(15) 
The installation, ownership and maintenance responsibilities after completion of the development for all stormwater drainage and storage facilities and all underdrainage facilities shall be identified on the preliminary plans and exhibits.
(16) 
All stormwater drainage or storage facilities or underdrainage facilities to be publicly dedicated shall be located in a right-of-way, a drainage easement or in a location as required by the Township.
(17) 
The design for all stormwater drainage and storage facilities shall be in accordance with the requirements of the Pennsylvania Department of Transportation Design Manual, Part 2, latest edition, and of § 185-51B(2) of this chapter.
(18) 
Plan and profile drawings to suitable scale shall be provided prior to preliminary plan approval. Plan and cross-section drawings, catalog cuts and specifications shall be provided showing complete construction details for all stormwater drainage storage facilities and appurtenances prior to final plan approval.
(19) 
The access control for any storage facility shall be approved by the Township prior to final plan approval.
(20) 
The design of all detention facilities shall be subject to the review and approval of the Township Engineer, and where applicable, by the Pennsylvania Department of Environmental Protection.
(21) 
Where open stormwater drainage and/or storage facilities are to be constructed, the access control measures, erosion control measures, capacity protection measures, flood protection measures, stagnant water control measures and appearance control measures shall be presented for Township approval with the preliminary plans and exhibits.
(22) 
Stormwater detention facilities shall have sufficient capacity to store the twenty-five-year return storm at a minimum except where a lesser return frequency (e.g., twenty-five-year, fifty-year, one-hundred-year) is determined to be appropriate at the sole discretion of the Township Engineer or where required by watershed studies. A minimum of two feet of freeboard shall be provided. The primary outlet structure shall be designed to control the two-, five-, ten- and twenty-five-year return storms. An emergency spillway shall be designed to convey the twenty-five-year post-developed return storm or larger, as appropriate. All dike embankments shall be a minimum eight feet wide at its crest.
(23) 
The design of stormwater drainage and storage facilities shall be closely correlated with the design of public streets.
(24) 
The depth of flow in gutters and allowable spread across the pavement shall be approved by the Township Engineer.
(25) 
Free flow of stormwater runoff shall not be permitted onto the cartway of any public street from a private driveway, access drive or any other vehicular right-of-way.
(26) 
Stormwater inlets shall be spaced a maximum of 300 feet apart where pipe sizes of 24 inches or less are used, and not over 450 feet where larger pipe sizes are installed. Sufficient inlets shall be provided to intercept all surface runoff.
(27) 
Grate inlets shall be depressed below the plane of the gutter.
(28) 
Curb inlets/openings shall have a maximum permitted height of six inches unless otherwise provided with a protective barrier.
(29) 
Design of inlets shall be as required of runoff calculations.
(30) 
Manholes shall be spaced a maximum of 300 feet apart where pipe sizes of 24 inches or less are used, and not over 450 feet where larger pipe sizes are installed. Design of manholes shall be as per Exhibits #11 through #17 of the West Deer Construction Standards.[2] If approved by the Township, inlets may be substituted for manholes.
[2]
Editor's Note: The West Deer Township Construction Standards are on file in the Township offices.
(31) 
Enclosed stormwater drainage courses shall be required at intersecting streets and elsewhere, as may be deemed necessary by the Township. Stormwater shall be collected in stormwater culverts or similar enclosed components.
(32) 
Stormwater culverts, bridges and similar structures serving public streets, access drives or any other vehicular right-of-way as may be designated by the Township shall be designed to support HS-20 and military loading and any other imposed loadings necessary without structurally damaging the drainage system. The stormwater culverts, bridges and similar structures shall be constructed to the full width of the right-of-way plus additional length as deemed necessary by the Township Engineer to satisfy a local drainage pattern.
(33) 
Stormwater culverts in areas other than those noted above shall be designed to support the necessary loading (existing and potential) and any other imposed loadings without structurally damaging the pipe or affecting its capacity for drainage. Said design shall be approved by the Township Engineer.
(34) 
Conduit size of culverts or other enclosed components of a stormwater drainage system shall be based on computed hydrologic and hydraulic data and computations shall be approved by the Township Engineer. Minimum size of any enclosed structure to be maintained by the Township shall be 15 inches in diameter.
(35) 
Minimum size of any enclosed structure to be privately maintained shall be 15 inches in diameter unless design calculations are provided that can justify a lesser size. Design calculations shall be approved by the Township Engineer.
(36) 
The design of the enclosed drainage course shall provide a minimum cleaning velocity of three feet per second. When the design provides for a maximum velocity greater than 10 feet per second, the enclosed components shall be lined or protected to prevent scour.
(37) 
The headwall and endwall structures for enclosed stormwater facilities shall be as per the requirements of Exhibit #26 of the Construction Standards[3] and approved by the Township Engineer.
[3]
Editor's Note: The West Deer Township Construction Standards are on file in the Township offices.
(38) 
Pipe materials used shall be reinforced concrete pipe (RCCP), Class III minimum, or smooth flow polyethylene pipe.
(39) 
Storm sewers 36 inches in diameter or less shall be constructed to line and grade.
(40) 
The pipe zone of storm sewers shall be installed in natural, virgin ground unless otherwise approved. The pipe zone shall be defined as the area outside the pipe diameter six inches below, six inches on either side and 12 inches above the pipe.
(41) 
Energy dissipaters shall be required at the outlet side of all enclosed culverts or similar components and shall be designed to reduce the velocity flow sufficient to prevent damage to downstream areas.
(42) 
No stormwater facility shall be enclosed or covered over until the Township has inspected and approved said facility.
B. 
Open drainageways.
(1) 
When open drainageways are proposed for the collection and/or discharge of stormwater, the Planning Commission and Board of Supervisors shall review the design of such in relation to capacity, safety, erosion and stagnation in consultation with the Allegheny County Soil Conservation Service.
(2) 
Drainage easements shall be provided for all existing and proposed drainageways, substantially conforming to the alignment thereof, and shall be of sufficient width to include all of the watercourse plus at least 10 feet from the center of the stream channel in either direction, but in no case shall be less than 20 feet in width.
(3) 
Stormwater shall be detained and discharged at predevelopment rates, on site as approved by the Township Engineer.
(4) 
Open stormwater drainagecourses shall be designed for a maximum velocity not to exceed 10 feet per second and a minimum velocity of five feet per second. A minimum velocity of three feet per second may be permitted where a greater slope cannot be achieved to permit the standard required minimum velocity. An open stormwater drainage course shall include a lining (riprap, concrete, bituminous) to prevent erosion. Any required approval of the Allegheny County Conservation District shall be obtained by the applicant.
Where possible, as determined by the Board of Supervisors upon the recommendation of the Township Engineer, electric, telephone, cable television and television transmission lines shall be placed underground. Where such lines are not placed underground, said lines shall be placed along rear lot lines to the fullest extent possible.
A. 
Width location. When easements are required for any utility serving a subdivision or land development, they must be a minimum of 20 feet wide and must, to the fullest extent possible, be adjacent to or centered on rear or side lot lines.
B. 
Natural gas lines. All natural gas lines shall be installed in compliance with the ASA Code B31, 80 1958, as amended. The minimum distance from a pressurized natural gas line to a dwelling unit or other structure shall be established by the applicable transmission or distribution company.
C. 
Petroleum lines. Between a proposed dwelling unit or other structure and the center line of a petroleum or petroleum products transmission line which may traverse the subdivision or land development, there must be a minimum distance of 100 feet measured in the shortest distance.
A. 
Material and size. Monuments and markers shall be constructed as follows:
Construction
Minimum Size
(inches)
Monument
Concrete
4 x 4 x 36
Marker
Iron pipes or iron or steel bars
24 x 3/4 diameter
B. 
Markings placement. Monuments and markers must be placed by a registered professional engineer or professional land surveyor so that the scored or marked point coincides exactly with the point of intersection of the lines being monumented. They must be set so that the top of the monument or marker is level with the surface of the surrounding ground. Monuments must be marked on top with a copper or brass dowel.
C. 
Monument location. Monuments must be set:
(1) 
At the intersection of lines forming angles in the perimeter boundaries of the tract.
(2) 
At the intersection of street rights-of-way when such are perpendicular or angular; or at the beginning and ending of street intersection right-of-way curves or chord diagonals where they are formed. All monuments shall be placed at a five-foot offset of the property line and in the right-of-way.
(3) 
At such other points as determined necessary by the Township Engineer.
D. 
Marker location. Markers must be set:
(1) 
At the beginning and ending of curves along street property lines if not monumented.
(2) 
At points where lot lines intersect curves either front or rear.
(3) 
At angles in property lines of lots.
(4) 
At all other lot corners.
E. 
Removal. Any monuments or markers that are removed must be replaced by a registered professional engineer or professional land surveyor at the expense of the person removing them.