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SECTION 2 - SEWER EXTENSIONS
2.1 DESIGN REQUIREMENTS
2.2 EASEMENTS
2.3 CONSTRUCTION DRAWING REQUIREMENTS
2.4
2.5 INSPECTION OF CONSTRUCTION
2.6 EXISTING SANITARY SEWERS
2.7 MAINTENANCE OF ACCESS
2.8 CREEK CROSSINGS
2.9 STEEP SLOPES
2.10 PIPE ZONE BACKFILL MATERIAL
2.11 EXCAVATION
2.12 CONCRETE CRADLE
2.13 BACKFILL MATERIAL FOR MANHOLE EXCAVATIONS
2.14 RESTORATION
2.15 JACKING
2.16 MANHOLES
2.17 PVC PIPE FOR GRAVITY SEWER SYSTEM
2.18 DUCTILE IRON PIPE & FITTINGS FOR GRAVITY SEWERS
2.19 FORCE
2.20 PVC PIPE FOR FORCE MAINS
2.21 DUCTILE IRON PIPE & FITTINGS FOR FORCE MAINS
2.22 FORCE
2.23 PRESSURE SEWER SYSTEM PIPING
2.24 ACCEPTANCE TESTING MAINS
2.25 CAST IN-PLACE CONCRETE
2.1 DESIGN REQUIREMENTS
2.1.1 In general, the sanitary sewers are to be designed for the ultimate tributary population. The design report to accompany the application for connection shall clearly present the design flow basis, including the breakdown of residential, commercial, and industrial flow rates. The average daily and peak hourly flow rates for each category shall be included.
2.1.2 Residential sewage flows shall be determined on the basis of 100 gallons per person per day and 3.5 persons per residential unit. Commercial and industrial sewage flows shall be determined on a fixture unit basis, or historical evidence documented by a similar establishment. The peak flow factor for sizing lateral and submain sewers shall be four (4) times the average flow rate. The peak flow factor for sizing main, trunk, and interceptor sewers shall be 2.5 times the average flow rate.
2.1.3 Sub-main, main, trunk and interceptor sewers shall be eight (8) inches in diameter or larger.
2.1.4 Service sewers to homes and commercial establishments and facilities that do not serve food, shall be six (6) inches in diameter, unless a minimum grade of 0.25 inches per foot can be maintained in which case service sewers may be four (4) inches. Minimum allowable grade for all service sewers is 0.125 inches per foot in all cases.
2.1.5 Service sewers to all commercial establishments and facilities that serve food shall be six (6) inches minimum diameter, and shall be equipped with an approved grease trap in conformance with the standard detail. The size of the grease trap will be approved by the Authority.
2.1.6 Eight (8) inch diameter sub-main, main, trunk and interceptor sewers shall have a minimum grade of one (1) percent (one (1) foot of fall per 100 feet of length).
2.1.7 Sewers shall be designed and constructed to give mean velocities, when flowing full, of not less than 2.0 feet per second based upon Kutter's Formula or Mannings' Equation using an "n" value of 0.013.
2.1.8 All sewers shall be designed to line and grade with uniform slope between manholes. Curvilinear alignments between manholes shall not be permitted.
2.1.9 In general, sewers should not be designed to be located in fill areas. In no case shall the pipe zone, as defined herein, and shown in the Standard Drawing be located in fill. Only under conditions approved by the Authority and Engineer will sewers be permitted in fill areas. When permitted, the sewer shall be structurally enhanced.
2.1.10 All sewers shall be designed to prevent damage from superimposed loads.
2.1.11 All sewers shall be designed to provide a minimum of four (4) feet of cover above the crown of the pipe, and to the extent practicable, a maximum depth of 15 feet.
2.1.12 Except where pipe crossings are required, a minimum of 10 feet horizontal and 18 inch vertical clearance shall be maintained between all other subsurface utilities including but not limited to gas, water, storm sewer, and electric. Where regulatory agency requirements are more stringent, they shall supersede this requirement.
2.1.13 All sewers at a depth over 15 feet shall be SDR-21, ductile iron pipe or SDR-35 with concrete encasement.
2.1.14 Service sewer lateral piping shall be supplied and installed in minimum 13-foot sections.
2.1.15 Ductile iron pipe shall not be permitted for use within the immediate 2500 lineal feet of a sewage force main discharge.
2.1.16 Design of pressure sewer system shall provide hydraulic calculations for review by Authority's Consulting Engineer for determination of piping size.
2.2 EASEMENTS
2.2.1 An exclusive permanent easement recorded in the name of the Authority of at least twenty (20) feet shall be provided for all proposed sanitary sewers. All sewers to be approved, accepted and conveyed to the Authority must be within the center of the sanitary sewer right-of-way (center 10 feet of a 20-foot wide right-of-way). For new subdivision plans, the 20-foot sanitary sewer easement shall be shown on the recorded subdivision plan. One blue line drawing and one reproducible Mylar of the recorded plan must be supplied to the Authority prior to construction of any sewer lines.
2.2.2 For proposed sewers, located outside the limits of the subdivision plan, rights-of-way agreements in the name of the Authority must be obtained prior to construction of the sewer lines. It is the responsibility of the Contractor to supply the Authority rights-of-way drawings in a form satisfactory to the Authority in order that the Authority may have its Solicitor prepare the necessary rights-of-way.
2.3 CONSTRUCTION DRAWING REQUIREMENTS
2.3.1 All sets of plans shall be prepared on standard 24" x 36" sheets with a 1" border on the left hand side and a 1/2" border on all other sides, and shall include a 3" x 5" title box in the lower right hand corner.
2.3.2 All sets of plans shall include a title sheet to identify the project by name, owner, and location, as well as a key map drawn at a scale not smaller than four hundred (400) feet per one (1) inch covering the entire area and boundary of the proposed project. The project key map shall show general layout of the sewers, and the arrangement of the construction drawings referenced by drawing number as they appear in the set.
2.3.3 The key map shall show all existing and proposed streets, water courses, and other salient topographic features, control lines for intervals of not less than five (5) nor more than ten (10) feet, general locations of all bench marks set during the design, and other such information as may be requested.
2.3.4 Construction drawings shall include both plan and profile views and shall be drawn at a horizontal scale of fifty (50) feet per one (1) inch maximum and a vertical scale of ten (10) feet per one (1) inch maximum and shall include the following information at a minimum:
A. Plan
1) Title block identifying project name, owner, date, sheet numbers, scale, and revision date/description blocks.
2) Design survey points, references, and baseline.
3) Base datum location, description and elevation. All elevations shall originate from sea level datum of 1929.
4) Temporary bench marks for reference during construction (at least one every 1500').
5) All pertinent topographic features, including all man made structures.
6) All existing or proposed subsurface utilities to include water, storm sewers, gas, electric, etc.
7) North arrow.
8) Locations of proposed service connections.
9) Proposed manhole locations with manhole reference number.
10) Location and perimeter limits of existing or proposed fill areas.
B. Profile
1) Sewer Centerline profiles to show existing and proposed surface elevations.
2) Minimum basement elevations for all proposed connections.
3) Pipe inverts at all manholes for all pipes.
4) Invert and surface elevation of all manholes.
5) Horizontal stationing at all manholes.
6) Length, grade and diameter of pipe between manholes.
7) Elevation table (in feet at Median Sea Level)
8) Location of all special appurtenances (i.e. concrete cradle, borings with casing pipe, concrete encasement, ductile iron pipe, anchors, drop connections, air/vacuum release valves, etc.)
C. Detail Sheets
1) Tabulation of design data by manhole run to include design flow rate, velocity, minimum design grades.
2) Scale construction drawings for all special conditions.
D. All copies of drawings furnished to the Authority should be of the dark-line type. At time of initial submission, a total of five (5) complete sets of drawings, including plan of subdivision, will be forwarded to the Authority. Upon completion of the project construction, six (6) sets of blue line prints and one (1) set of reproducible Mylars showing "as-built" conditions including all underground utilities, angles and distances between manholes, sides and brands and type of pipe, top and invert elevations of each manhole, exact location of all building sewer connections and the name of the Contractor shall be furnished the Authority before final approval of construction will be given.
All construction drawings stamped “Approved/No Exceptions Taken” may be subject to a current review after 3 years from the original approved date.
2.4
2.4.1 Prior to initiation of construction, the Contractor shall submit the following to the Authority:
A. A construction schedule showing dates of commencement and completion.
B. Four (4) copies of all shop drawings, manufacturers certifications and specifications, and drawings for all materials to be installed.
C. One (1) original copy of a notarized certification from each manufacturer supplying materials to be installed on the job, to include all pipe, manholes, frames and covers, valves, and other appurtenances, that their respective materials have been manufactured, inspected, and tested according to these specifications, and meet all requirements thereof. All materials used in the project shall bear identification or reference numbers for checking compliance with factory test results.
2.5 INSPECTION OF CONSTRUCTION
2.5.1 All construction of sewerage facilities in the Authority shall be subject to inspection by representatives of Authority to assure that such construction is accomplished in accordance with the approved plans and specifications.
2.5.2 At least ten (10) days prior to starting construction, the applicant shall notify the Authority of the anticipated starting date of his/her proposed construction and the schedule of operation through completion of the project. At the time of this notification, a meeting shall be arranged between the applicant, his/her construction foreman and representatives of the Authority to completely review all aspects of the construction project, prior to start of construction. The Contractor shall furnish to the Authority the names and telephone numbers of key personnel involved in the project, who may respond to Authority contact during off-work hours. This meeting is considered extremely important in the interests of both the Authority and the Contractor. Therefore, this requirement will be strictly enforced and no construction will be permitted without a meeting.
2.5.3 The responsibility for inspection of the construction project for the Authority will be with the Authority under the advice of the Consulting Engineer. Direct inspection of the construction will be performed by an inspector working under the direction of the Consulting Engineer and the Authority. The detailed method of operation and coordination between the Authority and its representatives and the Contractor will be completely reviewed at the pre-construction meeting referred to above. In general, however, the inspector will be the Authority's representative on the job, inspecting all materials and methods of construction to assure that they comply with the requirements of the approved plans and specifications and will have complete authority to enforce such requirements. It will be expected that the Contractor coordinates all construction activities with the inspector and is reasonable in the scheduling of construction during normal working hours. At no time shall the Contractor undertake any construction work without the knowledge of the inspector. If the requirements of the approved plans and specifications are not being met, the inspector can require verbally that the Contractor cease operations, which will then be followed with written notice, until compliance with the approved plans and specifications is gained.
2.5.4 Should any questions or controversies arise between the Contractor and the inspector, the decision of the Authority will be final.
2.5.5 Upon completion of the construction work, a detailed final inspection shall be made by the Authority to determine that the completed facilities have been constructed in accordance with the approved plans and specifications. Approval will not be given by the Authority until all discrepancies and deficiencies revealed by this final inspection have been satisfactorily corrected.
2.6 EXISTING SANITARY SEWERS
2.6.1 Existing sanitary sewers in close proximity to the Contractor's construction activities shall not be used as a drain for surface or ground water runoff during construction.
2.7 MAINTENANCE OF ACCESS
2.7.1 Those trenches which are located along or across existing improved surfaces (i.e. State and local roads, berms, driveways, parking areas, etc.) which must be made safe for vehicular traffic as soon as possible, shall be immediately backfilled to full depth of trench above the pipe zone with AASHTO No. 57, 67 (See PennDOT Publication 408, Section 703.2 (c)) or other similar angular graded material approved by the Authority's representative. Slag material is prohibited. The materials shall be placed in no greater than six (6) inch lifts (compacted density) and tamped with mechanical tampers or special vibratory equipment for compaction. In any event compaction shall be done in order that no settlement will take place in the trench areas.
2.7.2 In areas where trenches are located along or across paved areas, and where the trenching disturbs the existing paved surface, the Contractor will be required to complete temporary restoration of said disturbed surface prior to the cessation of his/her construction activities for that day, in the following prescribed manner.
A. The Contractor shall place graded granular material as prescribed in Item 2.5.1 to a point six (6) inches below the base of the existing improved surface. Slag material is prohibited. The Contractor shall neatly saw cut the edges of the pavement disturbed by the trench. The Contractor shall place
Bituminous base course (weather permitting) or bituminous cold patch from the top of the graded granular material to the top of the existing paved surface.
2.7.3 The Contractor shall be responsible for maintaining all crossings of improved surface areas until such time that permanent restoration can take place. The above shall include placement of additional graded granular material, bituminous base course (or cold patch) as required, or as directed by the Authority's representative.
2.8 CREEK CROSSINGS
2.8.1 All creek crossings shall be concrete encased in accordance with the concrete encasement detail as shown on the Standard Drawing.
2.8.2 A minimum of three (3) feet of cover above the crown of the pipe shall be maintained on all creek crossings, unless the sewer is located in rock. Where the stream crossing is located in rock, a minimum of one (1) foot of cover will be required. At the discretion of the Authority's representative, additional cover may be required for crossings of major streams.
2.9 STEEP SLOPES
2.9.1 Sewers constructed on slopes twenty (20%) percent or greater shall be of ductile iron (Class 52) or PVC SDR-21 construction and shall be securely anchored with concrete anchors in accordance with the Standard Drawing. An additional anchor is required on the immediate downstream side of the upper manhole.
2.10 PIPE ZONE BACKFILL MATERIAL
2.10.1 All pipe lines shall be supported on an AASHTO No. 57, 67 (See PennDOT Publication 408, Section 703.2 (c)) or other similar angular graded material approved by the Authority's representative, for the full width of the trench from a minimum depth of 0.5 feet below the bottom of the pipe to an elevation of one (1) foot above the top of the pipe in its installed position. See pipe zone detail on the Standard Drawing.
2.10.2 For ferrous metal pipe lines or casings, cinders or blast furnace slag type materials shall not be used as backfill material in the pipe zone and where such pipe lines are carried through cinders or blast furnace slag type materials, the Contractor shall supply a clay encasement for the entire pipe zone, plus six (6) inches minimum below the invert of the pipe.
2.11 EXCAVATION
2.11.1 The depth of trench for sewers, pressure sewers or force mains shall be such that the pipe in its installed position shall have a minimum of four (4) feet cover above the crown of the pipe.
2.11.2 In excavation for all sewers, where made in open cut and where space permits, the banks of the trench from the ground surface to a depth not closer than one (1) foot above the top of the pipe may be excavated to non-vertical and non-parallel planes. In no case shall the side walls of the trench in the pipe zone, defined as all that trench area below a point 12" above the top of the pipe in its installed position, be permitted to be other than vertical and parallel planes equal distant from the pipe centerline. The horizontal distance between the vertical planes shall be no greater than the outside diameter of the pipe plus 24 inches and not less than the outside diameter of the pipe plus 12 inches. If the pipe zone trench widths are exceeded, the Contractor shall install the pipe in concrete cradle.
2.11.3 Excavation for manholes or similar structures may be performed with non-vertical banks except in paved areas and traveled ways, or where such excavation will undermine adjacent facilities or structures, or where such excavation will violate private property outside the right-of-way established for this work. In paved areas and traveled ways, the Contractor shall limit the area of his excavation so that the length and width are a maximum of four (4) feet greater than the greatest length and width of the structure involved.
2.11.4 Insofar as is practical, the material excavated from the trench shall be used for backfill above the pipe zone. The Authority's representative shall determine whether material is unsuitable and upon notice from the Authority's representative unsuitable material shall be disposed of and bank run gravel or other suitable material shall be brought in from an outside source.
2.11.5 No frozen or excessively wet material or any other unsuitable material (at the discretion of the Authority's representative) will be permitted to be used as trench backfill. Suitable or selected backfill material shall be only materials used as backfill in the trench.
2.11.6 Contractor will be permitted to open not more than 100 lineal feet of ditch at any one time. Pipeline must be backfilled as soon as practicable after installation to protect installation and ensure public safety.
2.12 CONCRETE CRADLE
2.12.1 Concrete cradle and/or encasement is required to be furnished and installed at all locations where the required 18" vertical clearance cannot be maintained, and under all sewer pipe within the excavated areas around manholes and other structures wherein the specified trench widths are exceeded. Said cradle and encasement material shall consist of concrete as described in the Cast in Place Concrete Section of these specifications. Care shall be exercised in placing encasement or cradle to provide adequate anchorage for the sewer pipes in order to prevent flotation and/or displacement of the pipe.
2.12.2 The Contractor shall provide and install all reinforcing steel that may be required to assure adequate strength for the structures.
2.12.3 Concrete cradle and encasement shall be in accordance with the Standard Drawing.
2.12.4 All sanitary sewers located within areas of storm water retention ponds will be concrete encased.
2.13 BACKFILL MATERIAL FOR MANHOLE EXCAVATIONS
2.13.1 Where manholes are installed in paved streets, alleys, roads, berms, parking areas, driveways or other improved surface areas, the entire excavated area around the manhole shall be backfilled with a AASHTO No. 57, 67 stone, (see PennDOT Publication 408, Section 703.2 (c)) or other similar angular graded material approved by the Authority's representative. Slag material is prohibited. The angular graded material shall be installed completely around the manhole from its base to the bottom of the improved surface area. The angular graded material shall continue out of the manhole-excavated area through and around the inlet and outlet pipe trench area so that its surface forms an approximate 45-degree angle with the top of the manhole.
2.13.2 Where manholes are installed in unimproved areas, the entire excavated area around the manhole shall be backfilled with angular graded material from the base to a point 12 inches above the top of the highest pipe entering the manhole.
2.14 RESTORATION
2.14.1 Should settlements in excess of 1-1/2 inches below the street grade occur within a period of one (1) year, the Contractor shall furnish and install additional material to maintain the surface at street grade. Where the Contractor's operations destroy permanent type road surfaces, they shall restore the road surface in accordance with the requirements of the governing body (
2.14.2 Where excavation is made through planted, cultivated, lawns, or similar areas, the topsoil shall be removed and separately stored per property owners. Backfill material and placement shall be the same as previously specified, except that the backfill shall be carried to within six (6) inches of the final grade. The topsoil salvaged from the excavation (or brought in from an outside source) shall then be placed to approximately one (1) inch above the adjacent grade, rolled with a light roller, and seeded or planted to a condition equivalent to that existing before the commencement of construction. Seeding shall be done in accordance with good local practice and the seed mixture used shall produce a planted, cultivated surface equivalent to that existing before commencement of construction. Contractor shall furnish and re-plant grass, trees, shrubs, etc., which fail to survive within cultivated landscaped areas, for a period of one (1) year following the initial restoration.
2.14.3 Trenches, which are located in areas not specified in these specifications to be seeded or sodded, or in which surface settlement is not important in the opinion of the Authority, shall be filled above the pipe zone with a compactable material containing rocks or boulders no larger than eight (8) inches in maximum dimension. Mechanical tamping will not be required in this instance, however, the Contractor shall place the materials in no greater than 12 inch lifts (compacted density) and shall tamp as required to assure that no excessive voids are present in the backfill.
They shall carry the backfill in this manner to grade. They shall then add backfill neatly rounded over the trench to a sufficient height to allow for settlement to grade after consolidation. Future settlement within a period of one (1) year shall be immediately rectified by adding suitable material to bring the surface to a little above grade.
2.14.4 The Contractor shall make up all deficiency in backfill material and shall dispose of all excess material.
2.15 JACKING
2.15.1 Where jacking is employed, a minimum 1/2 inch thick steel shield at least 24 inches long shall be required to extend beyond the forward end of the liner plate or conduit being jacked. The outside radius of this shield shall not exceed the outside diameter of the pipe by more than one (1) inch. Excavation ahead of the conduit shall not be permitted to progress beyond the end of the shield being used.
2.15.2 Where the jacking or boring method is used, it shall be mandatory to conduct said operation from the high end of the pipe. The pipe shall at all times follow immediately behind the boring auger at a distance no greater than two (2) feet.
The method of auguring the entire hole and then pushing the pipe through will not be permitted. The pipe shall conform to the paragraph under the heading of "Steel Casing Pipe" of these specifications.
2.15.3 Where the boring or jacking method of construction is used, it shall be mandatory to conduct said operation well in advance of any pipe installation, at least one (1) manhole run above or below the boring location in order that the grade of the boring after installation can be met by adjusting either grade above or below the boring and maintain the proposed pipe grades.
2.15.4 The entire void space between the carrier pipe and casing pipe shall be filled with sand, or approved concrete aggregate material, placed by an approved method, to support and hold the carrier pipe in place. Both ends of the casing pipe shall be sealed with concrete.
2.15.5 STEEL CASING PIPE
2.15.5.1 Steel casing shall be extra strong pipe and shall be in compliance with
2.15.5.2 Minimum casing wall thickness:
Nominal Diameter Coated or Uncoated
of Casing Pipe Cathodically and
In Inches Protected Unprotected
14 and Under 0.188" 0.251"
14 and 16 0.219" 0.282"
18 0.250" 0.313"
20 0.281" 0.344"
22 0.312" 0.375"
24 0.344" 0.407"
26 0.375" 0.438"
29 and 30 0.406" 0.469"
32 0.438" 0.501"
43 and 36 0.469" 0.532"
2.16 MANHOLES
2.16.1 Manholes shall be installed at all changes in grade, size or alignment and at distances not greater than 400 feet for piping of 15" diameter or less, and 500 feet for sewers greater than 15" diameter.
2.16.2 Manholes subject to flooding shall be set at an elevation approximately 18-inches above finished grade and protected with watertight covers.
2.16.3 Manholes shall be located to permit passage of design flows while minimizing flow resistance.
2.16.4 The smallest angle as measured between the inlet and outlet lines shall be a minimum of 90 degrees, or greater.
2.16.5 Drop type manholes shall be inside drop type, in accordance with Standard Drawing, shall be provided for all locations where the incoming sewer is 2'-0" or more above the manhole invert. Where two or more inside drop lines are necessary, manholes shall be 5 feet diameter.
2.16.6 Manholes shall be located such that there are no more than two (2) inlet lines. Service connections direct to manholes are not permitted.
2.16.7 Manholes up to twenty-five (25) feet deep shall have an internal diameter of four (4) feet. Manholes greater than twenty-five (25) feet deep shall have an internal diameter of five (5) feet. Manholes greater than twenty-five (25) feet deep shall be equipped with fabricated aluminum gratings every eight (8) vertical feet, in accordance with the Standard Drawing.
2.16.8 All manholes for sewer 8" to 18" shall be pre-cast concrete base section manholes in accordance with the Standard Drawing. For sewers 18” and greater, the pre-cast concrete base section manholes shall be 5 feet diameter.
2.16.9 The pre-cast concrete base slab and base riser section shall be poured monolithically with the riser section having a minimum height of two (2) feet above the top of the base slab. The base slab shall extend a minimum of six (6) inches beyond the outside diameter of the precast base riser section in accordance with the Standard Drawing.
2.16.10 An eight (8) inch deep minimum sub-base of AASHTO No. 57, 67 (see PennDOT Publication 480, Section 703.2 (c)) or other similar angular graded material approved by the Authority's representative shall be placed beneath the manhole base. Prior to installing the subbase stone all loose material in the excavated area below the manhole shall be thoroughly removed.
2.16.11 New manhole connections shall be through approved flexible watertight sleeves poured into the manhole base at a minimum of four (4) inches above the manhole floor. A minimum of six (6) inches of concrete shall be required between the top of the manhole base section and the crown of the pipe entering or exiting the manhole.
2.16.12 Connections to existing pre-cast manholes shall be made by machine cored entry holes and a flexible watertight gasket connection.
2.16.13 Manholes shall not be ordered by the Contractor from the manufacturers, until complete field layout of the proposed pipeline is established with proper horizontal and vertical alignments of the proposed manholes.
2.16.14 Pre-cast concrete grade rings or concrete brick shall be used between the top pre-cast manhole section and the manhole frame to meet existing grades where required, and be anchored with a maximum build-up of twelve (12) inches. High-density polyethylene manhole adjusting rings shall also be permitted as manufactured by Ladtech, or approved equal.
2.16.15 Two (2) rings of a one (1) inch diameter flexible butyl rubber manhole joint sealant shall be used between all pre-cast manhole barrel sections and grade rings.
2.16.16 All pre-cast concrete manholes shall have an air entraining admixture added to the concrete to produce a 5% + 1.0% air content. Pre-cast manhole bottoms and barrel sections, which show excessive honeycombing, are subject to rejection at the discretion of the Authority's representative.
2.16.17 All pre-cast concrete manholes shall have blind lifting lugholes, which shall be filled with non-shrinking grout.
2.16.18 Manhole invert channels shall be formed with cast in place concrete, steel trowled, such that there is minimum flow turbulence. A minimum of two (2) inches of fall shall be provided within the manhole between the influent and effluent sleeves. A uniform grade shall be maintained through the manhole when installing the concrete invert. The formed channel shall conform to three-fourths the sectional area of the pipe. Wherever sewers enter manholes such that the invert of the sewer is less than 2'- 0" above the manhole bottom, a channeled concrete fillet shall be constructed to prevent the flow from splashing into the manhole.
2.16.19 Frames and covers for all standard manholes shall be fabricated of cast iron and shall conform to the details of the Standard Drawing. Watertight frames and covers, in accordance with the Standard Drawing, shall be installed where noted in these specifications. Manhole covers shall be furnished with lettering; "McCANDLESS AUTHORITY" placed as noted on Standard Drawings. Two 3/4" stainless steel anchor bolts shall be provided for each frame. The final setting of manhole castings shall be such that they conform to the existing or proposed ground slopes and shall be set to exclude surface water.
Where manholes are located along creeks or low areas subject to flooding and in areas where they are subject to being covered, the top elevations shall be set above grade as directed by the Authority's representative. Contact surfaces of frames and covers shall be machined so that covers rest securely in the frames. Two (2) rings of 1/2-inch diameter flexible butyl rubber joint sealant approved by the Authority shall be used between the manhole frame and the top precast concrete wall section of the manhole (or grade ring).
All standard manhole frames and covers shall be as manufactured by:
A. Allegheny Foundry Company
Pattern 109 - frame, Pattern 110 - cover
B. Neenah Foundry Company
Pattern R-1753 - frame and cover
C. Approved Equal
All watertight manhole frames and covers shall be as manufactured by:
A. Allegheny Foundry Company
Pattern 109W - frame, Pattern 110 - cover
B. Neenah Foundry Company
Pattern R-1755F2 frame and cover
C. Approved Equal
Watertight frames and covers shall be furnished with machined groove to receive an O‑ring seal.
2.16.20 Ladder rungs, furnished for manholes and diversion chambers, shall be fabricated of gray iron construction (minimum tensile strength of 40,000 psi), or shall be fabricated of a three-eights (3/8) inch minimum round steel step encapsulated with copolymer polypropylene plastic. Maximum distance from top of manhole casting to first step shall be no greater than eighteen (18) inches.
Ladder rungs shall meet the design loading requirements of
2.16.21 All manholes shall be furnished by the manufacturer with asphalt emulsion coating; spray applied to exterior wall/cone surfaces, as manufactured by
2.16.22 Manholes within 1000 lineal feet of the discharge point of a sewage force main; either proposed or existing manholes shall be epoxy coated on the interior wall surface of the manhole as manufactured by Sauereisen Inc., or approved equal.
2.17 PVC PIPE FOR GRAVITY SEWER SYSTEM
2.17.1 Polyvinyl chloride (PVC) sewer pipe shall have a standard dimension ratio of 35 (SDR 35) and a minimum pipe stiffness of 46 psi. The pipe and fittings shall comply with
2.17.2 The PVC plastic used in the pipe and fittings shall have a cell classification of 12454-B, 12454-C, or 13364-B, with a minimum tensile modulus of 500,000 psi, as defined in
2.17.3 All pipes shall be tested for stiffness and deflection. One (1) length per 200 lengths supplied, or at a minimum two (2) lengths per size and strength, shall be tested for compliance with Unibell Specification
2.17.4 Rubber gaskets shall comply in all respects with the physical requirements of
2.17.5 Pipe installation shall comply with Unibell Specifications
2.18 DUCTILE IRON PIPE
2.18.1 Ductile iron pipe shall be designed in accordance with
2.18.2 Pipe shall be double cement lined bituminous coated Class 52. Fittings shall be 250-psi pressure classification minimum.
2.18.3 All pipes shall be factory hydrostatically tested to 500 psi. Tensile strength and low temperature impact test shall be performed on at least one (1) pipe per 200 of each size used.
2.18.4 Gaskets shall conform to
2.19 FORCE
2.19.1 All force mains shall be designed for a velocity of 2 fps at design average having a Hazen-Williams“e” factor (roughness) of 100. Force main material shall be PVC pressure pipe, as specified in Section 2.20 of these specifications. Ductile iron piping shall be used where enhanced stability is required and/or at the Authority's discretion.
2.19.2 Force mains shall be designed to have a minimum of four (4) feet of cover above the crown of the pipe.
2.19.3 Automatic combination air/vacuum relief valves installed in access manholes shall be provided at all high spots.
2.19.4 The pipe shall be designed for an average trench depth of five (5) feet and installed with a minimum of four (4) feet of cover above the crown of the pipe.
2.19.5 Detectable mylar tape shall be installed over the plastic pressure pipe at a depth of no more than one (1) foot above the pipe. The tape shall be tested to insure continuity prior to acceptance of the Authority's representative. The tape shall be two (2) inches wide, mylar encased, in aluminum foil-safety color as approved by the Authority, with the custom words CAUTION - SANITARY SEWER FORCE
2.20 PVC PIPE FOR FORCE MAINS
2.20.1 PVC pressure pipe shall be designed, manufactured, and tested in accordance with
2.20.2 Each pipe shall bear the National Sanitation Foundation Seal of approval and comply with the requirements for Type 1, Grade J (PVC 1120) of
2.20.3 The joint shall be the push on type with a rubber O-Ring gasket conforming to
2.21 DUCTILE IRON PIPE
2.21.1 Ductile iron pipe shall be designed in accordance with
2.21.2 Pipe shall be double cement lined bituminous coated Class 52. Fittings shall be 250-psi pressure classification minimum.