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Sanitary Sewer Systems (Site)

Written and maintained by SynC.

Rev5
IssuedOct 12, 2026
LicenseCC BY 4.0
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1 Scope

1.1 Boundary of Work

NOTE This standard governs the materials, installation, testing, and acceptance of the gravity sanitary sewer that collects wastewater from the buildings on a site and conveys it to the point of discharge, and of the sewage force main that carries pumped flow from a lift station to the gravity system. (1.1.1)
NOTE The gravity scope begins five feet outside the foundation wall of each building, at the cleanout and transition fitting that Sanitary Waste And Vent PipingSanitary Waste and Vent PipingResolves to the current adopted revision.sync/sanitary-waste-and-vent-piping furnishes there, and ends at the connection to the public sewer, at the inlet of an on-site treatment facility, or at the headworks connection of a treatment plant shown on the drawings. (1.1.2)
NOTE The force main scope begins at the discharge connection at the limit of a packaged lift station, which is the downstream flange of its valve vault or the discharge flange at its basin wall, and ends at the receiving manhole on the gravity system, and it includes the pipe, its thrust restraint, its air valves and their vaults, its cleaning access, and the discharge manhole itself. (1.1.3)
NOTE Where the site cannot reach the public sewer by gravity, the lift station is a packaged unit furnished under Packaged Pump StationsPackaged Pump and Lift StationsResolves to the current adopted revision.sync/packaged-pump-stations, this standard delivers the gravity sewer to its influent connection, and this standard resumes at its discharge connection. (1.1.4)
NOTE Work outside this boundary is governed by the standards named below, and this standard defers to them rather than restating their requirements: (1.1.5)
  • The building drain and its termination five feet outside the foundation wall under Sanitary Waste And Vent PipingSanitary Waste and Vent PipingResolves to the current adopted revision.sync/sanitary-waste-and-vent-piping, and the grease interceptor and the grease waste run to it under Grease InterceptorsGrease InterceptorsResolves to the current adopted revision.sync/grease-interceptors
  • A sewage ejector or grinder pump with its basin inside or immediately adjacent to a building under Sump And Sewage PumpsSump and Sewage PumpsResolves to the current adopted revision.sync/sump-and-sewage-pumps
  • The site water main, including the water-side provisions at a sewer crossing, under Water Distribution PipingSite Water Distribution PipingResolves to the current adopted revision.sync/water-distribution-piping, and dry-utility duct banks and site utility coordination under Site UtilitiesSite UtilitiesResolves to the current adopted revision.sync/site-utilities
  • Trench excavation, worker protection in ordinary trenches, routine groundwater control, and backfill above the pipe zone under EarthworkEarthworkResolves to the current adopted revision.sync/earthwork, and engineered excavation support and designed dewatering under Excavation Support And DewateringExcavation Support and DewateringResolves to the current adopted revision.sync/excavation-support-and-dewatering
  • Pavement and aggregate base restored over completed trenches under Aggregate Base CourseAggregate Base CourseResolves to the current adopted revision.sync/aggregate-base-course, and construction-phase sediment control under Erosion And Sediment ControlErosion and Sediment ControlResolves to the current adopted revision.sync/erosion-and-sediment-control
NOTE The pipe zone of the sewer trench, from the trench bottom through the bedding, haunch, and initial backfill to 12 in. above the pipe crown, is within this standard; EarthworkEarthworkResolves to the current adopted revision.sync/earthwork resumes above the pipe zone and supplies the backfill class and compaction target for the area in which the trench falls. (1.1.6)
NOTE A sewer or force main inside the fence of a water or wastewater treatment plant is process piping and is outside this standard; a sewer or force main that enters the plant from the collection system is governed by this standard up to the headworks connection shown on the drawings. (1.1.7)
1.1.8 The Contractor shall install the system at the alignment, slope, and invert elevations shown, and shall not adjust them to suit field conditions without the written direction of the Engineer of Record.
1.1.9 The Contractor shall report to the Engineer of Record any condition that prevents the system from being built as drawn, including a utility conflict, insufficient cover, insufficient slope, an existing invert that differs from the one shown, and a trench bottom that differs from the geotechnical report.
NOTE A sanitary sewer is a coordination problem before it is a piping problem: the invert at the point of connection fixes every upstream invert, rim, and cover on the site, and the decision whether a lift station is needed at all follows from that one elevation and the site grades, so the connection invert is verified before anything upstream of it is ordered. (1.1.10)

1.2 Utility Ownership

1.2.1 Where the sewer or the force main will be dedicated to a public utility for ownership and operation, the utility's design standards, approved product lists, standard details, and acceptance procedures shall govern over the selections in this standard wherever they differ.
1.2.2 The ownership disposition of the sewer after acceptance shall be as indicated in the datasheet.
Sewer Ownership After Acceptanceradio
○ Privately owned and maintained by the Owner
○ To be dedicated to the public utility
Per drawings — the civil general notes and the utility agreement (deferred by default)
1.2.3 Where the sewer will be dedicated, the Contractor shall obtain the utility's approval of the materials submittal before any pipe or structure is ordered, and shall schedule the utility's inspections and witness tests as hold points in the sewer work.
1.2.4 Work within the public right-of-way and at the point of connection shall conform to the utility owner's published standard specifications and details, which the Contractor shall obtain before that work begins.
NOTE A utility that will own the sewer for decades has standardized its pipe, its manhole pattern, its casting, and its test, so that one crew can maintain every reach in its system, and a sewer that meets this standard but not that list is rejected at the dedication inspection after it is in the ground. (1.2.5)

2 Referenced Standards

2.1 Materials, fabrication, installation, and testing shall comply with the latest adopted edition of each of the following unless a specific edition is cited in the Contract Documents.
2.2 Where the Contract Documents, the adopted code, the utility owner's standards, and the referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
Standard Title
ASTM D3034 Type PSM Poly(Vinyl Chloride) (PVC) Sewer Pipe and Fittings
ASTM F679 Poly(Vinyl Chloride) (PVC) Large-Diameter Plastic Gravity Sewer Pipe and Fittings
ASTM F794 Poly(Vinyl Chloride) (PVC) Profile Gravity Sewer Pipe and Fittings Based on Controlled Inside Diameter
ASTM F949 Poly(Vinyl Chloride) (PVC) Corrugated Sewer Pipe With a Smooth Interior and Fittings
ASTM D3212 Joints for Drain and Sewer Plastic Pipes Using Flexible Elastomeric Seals
ASTM F477 Elastomeric Seals (Gaskets) for Joining Plastic Pipe
ASTM F714 Polyethylene (PE) Plastic Pipe (DR-PR) Based on Outside Diameter
ASTM F2620 Heat Fusion Joining of Polyethylene Pipe and Fittings
ASTM F2164 Field Leak Testing of Polyethylene (PE) and Crosslinked Polyethylene (PEX) Pressure Piping Systems Using Hydrostatic Pressure
ASTM D2321 Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications
ASTM D2487 Classification of Soils for Engineering Purposes (Unified Soil Classification System)
ASTM C700 Vitrified Clay Pipe, Extra Strength, Standard Strength, and Perforated
ASTM C425 Compression Joints for Vitrified Clay Pipe and Fittings
ASTM C12 Installing Vitrified Clay Pipe Lines
ASTM C76 Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe
ASTM C1479 Installation of Precast Concrete Sewer, Storm Drain, and Culvert Pipe Using Standard Installations
ASTM C443 Joints for Concrete Pipe and Manholes, Using Rubber Gaskets
ASTM C478 Circular Precast Reinforced Concrete Manhole Sections
ASTM C877 External Sealing Bands for Concrete Pipe, Manholes, and Precast Box Sections
ASTM C913 Precast Concrete Water and Wastewater Structures
ASTM C923 Resilient Connectors Between Reinforced Concrete Manhole Structures, Pipes, and Laterals
ASTM C990 Joints for Concrete Pipe, Manholes, and Precast Box Sections Using Preformed Flexible Joint Sealants
ASTM D3753 Glass-Fiber-Reinforced Polyester Manholes and Wetwells
ASTM C1244 Concrete Sewer Manholes by the Negative Air Pressure (Vacuum) Test Prior to Backfill
ASTM F1417 Installation Acceptance of Plastic Non-Pressure Sewer Lines Using Low-Pressure Air
ASTM C924 Testing Concrete Pipe Sewer Lines by Low-Pressure Air Test Method
ASTM C828 Low-Pressure Air Test of Vitrified Clay Pipe Lines
ASTM C969 Infiltration and Exfiltration Acceptance Testing of Installed Precast Concrete Pipe Sewer Lines
ASTM C1103 Joint Acceptance Testing of Installed Precast Concrete Pipe Sewer Lines
ASTM A48/A48M Gray Iron Castings
ASTM A536 Ductile Iron Castings
AASHTO M306 Drainage, Sewer, Utility, and Related Castings
AWWA C104/A21.4 Cement-Mortar Lining for Ductile-Iron Pipe and Fittings for Water
AWWA C105/A21.5 Polyethylene Encasement for Ductile-Iron Pipe Systems
AWWA C110/A21.10 Ductile-Iron and Gray-Iron Fittings
AWWA C111/A21.11 Rubber-Gasket Joints for Ductile-Iron Pressure Pipe and Fittings
AWWA C151/A21.51 Ductile-Iron Pipe, Centrifugally Cast
AWWA C153/A21.53 Ductile-Iron Compact Fittings
AWWA C512 Air-Release, Air/Vacuum, and Combination Air Valves for Water and Wastewater Service
AWWA C517 Resilient-Seated Cast-Iron Eccentric Plug Valves
AWWA C600 Installation of Ductile-Iron Mains and Their Appurtenances
AWWA C605 Underground Installation of Polyvinyl Chloride (PVC) and Molecularly Oriented Polyvinyl Chloride (PVCO) Pressure Pipe and Fittings
AWWA C900 Polyvinyl Chloride (PVC) Pressure Pipe and Fabricated Fittings, 4 In. Through 60 In.
AWWA C906 Polyethylene (PE) Pressure Pipe and Fittings, 4 In. Through 65 In., for Waterworks
AWWA M23 PVC Pipe: Design and Installation
ASCE MOP 60 / WEF MOP FD-5 Gravity Sanitary Sewer Design and Construction
GLUMRB Recommended Standards for Wastewater Facilities (Ten States Standards)
29 CFR 1926 Subpart P Excavations
29 CFR 1910.146 Permit-Required Confined Spaces
2.4 The governing edition, the utility owner's standard specifications, and the state regulation on water and sewer separation shall be confirmed with the Authority Having Jurisdiction and the utility owner before any pipe is ordered.

3 Submittals

3.1 Action Submittals

3.1.1 The Contractor shall submit the following for the Engineer of Record's review and acceptance before any pipe, structure, casting, or valve is procured or fabricated:
  • Product data for each pipe and fitting material, identifying the governing product standard, the dimension ratio or strength class, the joint type, and the gasket material and its governing standard
  • Product data for force main pipe, fittings, restraint devices, air valves, and isolation valves, identifying the pressure class or dimension ratio and the lining and coating
  • Shop drawings for each manhole, showing barrel diameter, section heights, base type, top configuration, reinforcement, pipe opening locations and connector type, drop assemblies, interior protection, lifting hardware, and load rating
  • Product data for every frame and cover, identifying the casting alloy and grade, the AASHTO M306 proof-load listing, the clear opening, the legend, the ventilation, the restraint, and any utility owner pattern number
  • Product data for chimney seals, inflow dishes, grade rings, cleanout boxes, tracer wire, and marking tape
  • Gradation test results for each proposed bedding and embedment material source, classified in accordance with ASTM D2321
  • Thrust restraint calculation for the force main, showing the restrained length at each fitting or the thrust block bearing area, with the soil bearing values used
  • Testing plan identifying the leakage test method, test pressures or heads, hold times, mandrel sizes, video equipment, the independent testing agency, and the reaches and structures to be tested
  • Connection details, permits, flow management plan, and utility owner approvals for each connection to an existing or public sewer
  • Procedure for maintaining the record-set markup of installed alignments, inverts, lateral locations, and materials
Action Submittals Requiredcheckbox
☐ Gravity pipe and fitting product data with governing standard, class, and joint type
☐ Force main pipe, restraint, air valve, and isolation valve product data
☐ Manhole shop drawings with load rating, pipe openings, drops, and interior protection
☐ Frame and cover product data with AASHTO M306 listing and legend
☐ Chimney seal, inflow dish, grade ring, cleanout box, and locating product data
☐ Bedding and embedment gradation test results
☐ Force main thrust restraint calculation
☐ Testing plan with methods, pressures, hold times, and agency
☐ Existing-sewer connection details, flow management plan, and utility owner approvals
☐ Record-set markup procedure
3.1.2 Sanitary sewer below grade shall not be installed in any area for which the action submittals covering that work remain unaccepted.

3.2 Closeout Submittals

3.2.1 Before substantial completion the Contractor shall submit the following:
  • Record drawings showing installed plan and profile, station and offset from permanent reference points, finished rim elevation and every pipe invert at each manhole, the station, depth, and end location of every lateral and cleanout, pipe material and size by reach, the force main alignment with the location of every air valve and fitting, and every deviation from the Contract Documents
  • Signed field test reports for every leakage test, vacuum test, deflection test, and force main pressure test, showing the reach or structure identification and a pass or fail determination for each
  • Video inspection recordings and logs where video inspection is required
  • Manufacturer warranties for castings, precast structures, air valves, and isolation valves, assigned to the Owner
  • Certification that the system has been cleaned and that all plugs, bypass connections, and temporary flow controls have been removed
  • Authority Having Jurisdiction and utility owner acceptance documentation for any portion of the system connected to or to be dedicated to public infrastructure
Closeout Submittals Requiredcheckbox
☐ Record drawings with rim, invert, lateral, and force main appurtenance locations
☐ Signed field test reports with pass or fail by reach and structure
☐ Video inspection recordings and logs
☐ Assigned manufacturer warranties
☐ Cleaning and temporary-control removal certification
☐ Authority Having Jurisdiction and utility owner acceptance documentation
3.2.2 Lateral end locations shall be recorded on the record drawings by station and offset from the downstream manhole and by depth below finished grade, measured after the lateral is laid, not copied from the design drawings.
NOTE The lateral record is the drawing the Owner opens first when a building is added, a lateral is televised, or a dig-in is reported, and a lateral recorded from the design rather than from the trench is the one the excavator does not find. (3.2.3)

4 Quality Assurance

4.1 Installer Qualifications

4.1.1 The Contractor performing sanitary sewer work shall have completed not fewer than three projects of comparable pipe size, depth, and structure count within the preceding five years, and shall submit those project references on request.
4.1.2 Personnel assembling gasketed joints shall be trained in the joint manufacturer's assembly procedure, including gasket seating, lubricant application, and home-mark verification.
4.1.3 Personnel performing butt fusion or electrofusion of polyethylene pipe shall hold current qualification from the pipe manufacturer or a fusion equipment manufacturer for the procedure and pipe size used, and the fusion machine shall record a data log for every joint.
4.1.4 The first three joints of each pipe material and size installed on the project shall be assembled in the presence of the Engineer of Record's inspector, and production work in that material and size shall not proceed until those joints are accepted.
NOTE The demonstration joint requirement catches the systematic errors, the wrong lubricant, the gasket rolled at the same point on every joint, the home mark ignored, at three joints instead of at the leakage test, when the reach is backfilled and the pavement is scheduled. (4.1.5)

4.2 Product Identification and Marking

4.2.1 Pipe, fittings, gaskets, castings, and precast structures shall bear the manufacturer's identification, the governing product standard designation, and a production date or lot number sufficient to trace the item to its certification records.
4.2.2 Pipe, structures, or castings that cannot be traced to certification records shall be rejected and removed from the site, and the cost of removal and replacement shall be borne by the Contractor.
4.2.3 The Contractor shall verify that PVC pipe delivered to the site carries the sewer pipe standard designation, and shall not install drain-waste-vent pipe, Schedule 40 pressure pipe, or irrigation pipe as sanitary sewer.
4.2.4 Castings installed within the public right-of-way shall additionally bear the foundry identification, the AASHTO M306 proof-load marking, and any pattern number required by the utility owner.

4.3 Preinstallation Conference

4.3.1 Before sanitary sewer installation begins the Contractor shall convene a preinstallation conference attended by the Contractor's site utility superintendent, the plumbing subcontractor responsible for the building drain, the civil engineer of record, the geotechnical engineer of record, the testing agency, and the Authority Having Jurisdiction's or utility owner's inspector where that attendance is required by the permit.
4.3.2 The conference shall review the connection invert and the sequence for verifying it, pipe materials and joint assembly, the embedment and compaction requirements, dewatering and flotation control, water main separation at every crossing, the testing program and acceptance criteria, the inspection hold points, the procedure for connecting to existing sewers and managing live flow, and the procedure for reporting differing site conditions at the trench bottom.

4.4 Inspection Hold Points

4.4.1 The Contractor shall give the Engineer of Record and the Authority Having Jurisdiction's inspector not less than 24 hours' notice before each hold point listed below, and shall not proceed past a hold point until the inspection has been performed and released in writing:
  • Verification of the invert, size, and material at the point of connection, before any pipe is ordered
  • Trench bottom, before bedding is placed
  • Bedding surface and pipe alignment, grade, and joints, before embedment is placed
  • Water main separation at each crossing and parallel run, before embedment is placed
  • Structure foundation, before the base section is set
  • Pipe penetrations and resilient connectors at each structure, before exterior backfill
  • Embedment compaction in the pipe zone, before final backfill
  • Leakage testing, vacuum testing, deflection testing, force main pressure testing, and video inspection
  • Frame and casting elevation, before final pavement placement
4.4.2 Where an inspection is not performed within 24 hours of the scheduled time through no fault of the Contractor, the Contractor may proceed past the hold point after notifying the Engineer of Record in writing, and the Owner shall bear the cost of any later uncovering required to inspect that work.

5 Watertightness and Infiltration Control

5.1 Every pipe joint, structure joint, and pipe-to-structure connection in the sanitary sewer shall be a watertight joint qualified by a laboratory hydrostatic test of the joint assembly under its governing product standard.
5.2 Mortar-only joints, mastic-only joints, un-gasketed tongue-and-groove joints, solvent-cement joints on buried gravity sewer, and grouted pipe penetrations shall not be used anywhere in the sanitary sewer.
5.3 Mortar, external sealing bands, and joint wraps are supplementary to a gasketed or fused joint and shall not be substituted for it.
NOTE Infiltration and inflow, the groundwater and stormwater that enter a sanitary sewer through defective joints, cracked structures, unsealed penetrations, and vented or leaking covers, consume the hydraulic capacity of the sewer and the treatment plant, are metered and billed to the Owner where the sewer discharges to a utility, and are the most common reason a utility rejects or conditionally accepts a new collection system; every joint, connector, seal, and test in this standard exists to keep that water out. (5.4)
NOTE A storm sewer is accepted when it carries what it was built to carry, and a sanitary sewer is accepted when it carries nothing else, which is why the sanitary standard has no silt-tight or soil-tight joint class, no vented cover default, and no reach that is accepted on video alone. (5.5)

6 Gravity Sewer Pipe

6.1 Permitted Materials

6.1.1 The gravity sewer pipe materials permitted on the project shall be as indicated in the datasheet.
Permitted Gravity Sewer Pipe Materialscheckbox
Any of:
☑ Solid-wall PVC sewer pipe per ASTM D3034
☐ Large-diameter solid-wall PVC sewer pipe per ASTM F679
☐ Profile-wall PVC sewer pipe per ASTM F794 or ASTM F949
☐ Solid-wall polyethylene pipe per ASTM F714, butt-fused
☐ Ductile iron pipe per AWWA C151
☐ Vitrified clay pipe per ASTM C700
☐ Reinforced concrete pipe per ASTM C76
6.1.2 The pipe material, size, slope, and invert elevations for each reach, main and lateral alike, shall be as indicated on the sanitary sewer plan and profile.
NOTE The datasheet establishes which materials may appear anywhere on the project; the plan and profile establishes which of them is used in a given reach, and a material shown on the drawings but not permitted in the datasheet shall be reported to the Engineer of Record before it is ordered. (6.1.3)
6.1.4 The Contractor shall not change pipe material within a reach between two structures.
6.1.5 Where the drawings permit more than one material for a reach, the Contractor shall submit the proposed material for that reach for the Engineer of Record's acceptance before ordering.
NOTE Solid-wall PVC is the pipe nearly every site sanitary sewer at ordinary depth is built with, gasketed, light, and jointed in a few seconds; its limit is the deflection a flexible pipe takes when the embedment is poor, which is why its acceptance test is a mandrel. Profile-wall PVC reaches larger diameters at a lower cost per foot with a thinner effective wall and a lower stiffness. Butt-fused polyethylene has no gasketed joint at all, so it is the pipe of a directional-drilled crossing, a reach in unstable or settling ground, and a reach where the Owner wants zero joint leakage; its cost is fusion labor, a fused string that must be pulled or laid as a unit, and a wall that deflects more than PVC at the same dimension ratio. Ductile iron carries the loads no plastic class covers, at shallow cover, under a footing, and at a water main crossing, and it depends on its lining in sewage service. Vitrified clay is immune to the sulfuric acid that forms in a sewer and to every solvent a tenant can pour down a drain, and it is the pipe utilities with century-old clay sewers still specify; it is rigid, heavy, and short, so it has the most joints per hundred feet. Reinforced concrete reaches the trunk-sewer diameters nothing else does, and in sewage service its crown is attacked above the waterline unless it is lined. (6.1.6)
6.1.7 The design criteria under which the civil engineer of record set the minimum slope and self-cleansing velocity of each reach shall be as indicated in the datasheet.
Governing Gravity Sewer Design Criteriaselect
The utility owner's design standards
The state wastewater design regulation
Recommended Standards for Wastewater Facilities, Ten States Standards
ASCE MOP 60 and WEF MOP FD-5
NOTE The datasheet records the criterion the profile was designed to, so that a reviewer, a utility, and a contractor pricing a flatter alternative are reading the same rule; it does not license the Contractor to re-derive a slope. Where the utility owner or the state has adopted criteria, that adoption governs the choice, and the Ten States Standards and ASCE MOP 60 are the references an engineer designs to where no adopted criterion exists; the differences between them are in the minimum slope tabulated for the smallest pipes and in the manhole spacing permitted for the cleaning equipment the owner runs. (6.1.8)
6.1.9 A manhole is shown at every change in pipe size, slope, alignment, or material, at every junction of two or more sewers, and at the upstream end of each main, and the Contractor shall not add, omit, or relocate a manhole without the written direction of the Engineer of Record.

6.2 Solid-Wall and Profile-Wall PVC Pipe

6.2.1 Requirements in this article apply where solid-wall or profile-wall PVC sewer pipe is permitted in the datasheet.
6.2.2 Solid-wall PVC sewer pipe shall conform to ASTM D3034 in sizes 4 in. through 15 in. and to ASTM F679 in sizes 18 in. and larger.
6.2.3 Profile-wall PVC sewer pipe shall conform to ASTM F794 or ASTM F949 for the size supplied, and shall have a smooth interior.
6.2.4 The dimension ratio of solid-wall PVC sewer pipe shall be as indicated in the datasheet.
Solid-Wall PVC Sewer Pipe Dimension Ratioselect
SDR 35
SDR 26
SDR 23.5
SDR 21
NOTE A lower dimension ratio is a thicker wall and a stiffer pipe, and is specified where cover is deep, where the pipe is under a heavily loaded pavement, where the reach is a directional-drill pull, or where the embedment cannot be relied on to provide the side support that a thinner-walled pipe needs; SDR 35 carries the pipe stiffness the ASTM D2321 installation and the mandrel test were written around, and the stiffer classes buy margin against deflection at a higher price per foot. (6.2.5)
6.2.6 PVC sewer pipe joints shall be integral bell-and-spigot joints with a gasket conforming to ASTM F477, qualified to ASTM D3212.
6.2.7 The gasket shall be factory-installed in the bell or on the spigot, and a loose gasket shall not be installed in the field.
6.2.8 PVC sewer pipe shall be installed in accordance with ASTM D2321.

6.3 Polyethylene Pipe

6.3.1 Requirements in this article apply where solid-wall polyethylene pipe is permitted in the datasheet.
6.3.2 Polyethylene gravity sewer pipe shall conform to ASTM F714, of PE4710 material, with a smooth interior and a dimension ratio as indicated in the datasheet.
Polyethylene Gravity Sewer Pipe Dimension Ratioselect
DR 17
DR 21
DR 26
DR 32.5
NOTE Polyethylene has a lower modulus than PVC, so at the same dimension ratio it deflects more under the same embedment, and the dimension ratio for a gravity reach is selected against the cover and the embedment class rather than against pressure; DR 17 and DR 21 are the walls that hold the deflection limit in this standard under ordinary cover with Class I or Class II embedment, DR 26 serves shallow reaches in good ground, and DR 32.5 is the thinnest wall sold for gravity service and holds the limit only where the embedment is crushed stone placed and worked as this standard requires. (6.3.3)
6.3.4 Polyethylene pipe shall be joined by butt fusion in accordance with ASTM F2620, or by electrofusion couplings where a butt fusion machine cannot be used, and the fused string shall be allowed to cool to ambient temperature before it is moved or lowered.
6.3.5 Mechanical couplings on polyethylene gravity sewer shall be used only at a transition to another material or at a manhole connection, and shall be restrained or stiffened with an internal stiffener as the coupling manufacturer requires.
NOTE A fused polyethylene string shrinks as it cools and continues to move with temperature after it is laid, and a joint made or a connection fixed while the string is still warm from fusion or from the sun pulls out of alignment at the structure it was tied to. (6.3.6)
6.3.7 Polyethylene pipe shall be installed in accordance with ASTM D2321.

6.4 Ductile Iron Pipe

6.4.1 Requirements in this article apply where ductile iron pipe is permitted in the datasheet, and the lining article below also applies to ductile iron force main pipe selected under this standard.
6.4.2 Ductile iron pipe shall conform to AWWA C151, fittings shall conform to AWWA C110 or AWWA C153, and push-on, mechanical, and restrained joints shall conform to AWWA C111.
NOTE Ductile iron is specified on a sanitary sewer where the pipe must carry a structural load no gravity pipe class covers, where it passes beneath a footing or an equipment pad, where vertical separation from a water main is below the regulatory minimum, where restrained joints are required at a crossing, and for a force main where the pressure or the surge exceeds what a plastic pipe of the available diameter carries. (6.4.3)
6.4.4 The interior lining of ductile iron pipe in sewage service shall be as indicated in the datasheet.
Ductile Iron Pipe Interior Lining in Sewage Serviceselect
Ceramic-filled amine-cured epoxy lining
Polyethylene lining
Calcium aluminate cement-mortar lining
Cement-mortar lining per AWWA C104
NOTE Hydrogen sulfide released from sewage forms sulfuric acid on the pipe crown above the waterline, and ordinary cement mortar lining is consumed by it, so the lining of a sewage line is chosen for acid resistance rather than for the smooth bore a water line wants. The ceramic-filled epoxy is the lining nearly every sewage ductile iron specification carries, applied at the foundry to a measured thickness and holiday-tested; a polyethylene lining is thermally bonded and is specified by owners who standardize on it; calcium aluminate mortar resists the acid chemically and is used where a cementitious lining is wanted for its thickness; ordinary cement mortar is the position for a force main that runs full and for a reach that never sees a free surface, where no crown exists to attack. (6.4.5)
6.4.6 Ductile iron pipe shall be furnished with the exterior coating the manufacturer applies as standard and shall be encased in polyethylene in accordance with AWWA C105 where the soil investigation identifies the soil at the pipe as corrosive to iron.
6.4.7 Ductile iron pipe shall be installed in accordance with AWWA C600, and the bedding, embedment, joint assembly, structure connection, and testing requirements of this standard apply to it.

6.5 Vitrified Clay Pipe

6.5.1 Requirements in this article apply where vitrified clay pipe is permitted in the datasheet.
6.5.2 Vitrified clay pipe shall conform to ASTM C700, extra strength, and joints shall be factory-applied compression joints conforming to ASTM C425.
6.5.3 Vitrified clay pipe shall be installed in accordance with ASTM C12, with the bedding class the manufacturer publishes for the trench depth and load.
NOTE Clay is a rigid pipe that carries load in its wall, so its capacity is set by the strength class and the bedding rather than by the embedment stiffness that a plastic pipe depends on, and a clay reach is accepted on the leakage test and video without a mandrel. (6.5.4)

6.6 Reinforced Concrete Pipe

6.6.1 Requirements in this article apply where reinforced concrete pipe is permitted in the datasheet.
6.6.2 Reinforced concrete sewer pipe shall conform to ASTM C76 in the strength class indicated on the pipe schedule, with single-offset or bell-and-spigot joints and a confined O-ring or profile rubber gasket conforming to ASTM C443.
6.6.3 Reinforced concrete pipe in sewage service shall be furnished with a thermoplastic liner sheet cast into the interior from springline to springline over the crown, or with an interior coating the manufacturer certifies for sewage service, unless the Contract Documents direct otherwise.
6.6.4 Reinforced concrete pipe shall be installed in accordance with ASTM C1479 for the installation type indicated on the trench and bedding details.
NOTE The strength class and the installation type are selected together, because the ASTM C1479 standard installations trade compaction effort in the haunch against required pipe strength for the same fill height, and a bedding installed to a lower type than the class was selected for removes strength the design counted on. (6.6.5)

6.7 Fittings and Manufactured Branches

6.7.1 Fittings shall be of the same material, class or stiffness, and joint type as the pipe they serve, and shall be furnished by the pipe manufacturer or qualified by the pipe manufacturer for use with that pipe.
6.7.2 Field-fabricated branch connections, saddles cut into the pipe barrel without a manufactured fitting, and mitered elbows assembled on site shall not be used.
NOTE A field-cut branch removes wall at the one location where the pipe is already carrying a stress concentration, and the hand-mortared stub it is finished with is the single most common infiltration path a sewer video finds. (6.7.3)

7 Service Laterals and Building Sewers

7.1 Lateral Size and Slope

7.1.1 The building sewer and each service lateral shall be of a material permitted in the datasheet for the gravity sewer, and its size, slope, and invert shall be as indicated on the plan and profile, not less than Adopted Plumbing CodeAdopted Plumbing CodeParameterEach project supplies its own value.adopted-plumbing-code requires for a building sewer serving the connected drainage fixture units.
NOTE The building sewer is the one reach of the site sewer the plumbing code reaches, because the code governs the drainage system of the building out to the public sewer, so its minimum size and slope are a code floor, and the civil profile may set them steeper or larger but never below that floor. (7.1.2)
7.1.3 The lateral shall be laid in a straight line from the main to the building drain termination, and a change of direction shall be made with a manufactured fitting of not more than 45 degrees, with a cleanout as required by this standard.
7.1.4 Where a lateral must be installed at a slope flatter than the profile shows because of an invert condition found in the field, the Contractor shall report the condition to the Engineer of Record before laying the lateral, and shall not lay it at the flatter slope without written direction.

7.2 Connection to a New Main

7.2.1 The connection of each lateral to a new main shall be made with the fitting indicated in the datasheet, installed as the main is laid.
Lateral Connection to a New Mainselect
Factory-molded wye fitting
Factory-molded tee-wye fitting
Factory-molded tee fitting
Connection at a manhole
NOTE A wye turns the lateral into the main at 45 degrees in the direction of flow, so the entering flow does not strike the far wall of the main or back up the opposite branch, and it is the connection nearly every utility and the plumbing codes expect; a tee-wye gives the same sweep in a fitting that can be set with the branch vertical in a deep trench; a tee enters at 90 degrees and is admitted by some owners on the smallest mains where a wye cannot be rotated into the available space; a connection at a manhole is used where the lateral is 6 in. or larger, where the Owner wants every lateral inspectable from a structure, or where the main is too deep to connect at pipe level. (7.2.2)
7.2.3 Lateral branch fittings shall be installed with the branch rotated above the springline of the main, at the angle the utility owner or the plan and profile shows, so that the lateral falls to the main and the main cannot back up into the lateral at ordinary flow.
7.2.4 A lateral stub that will not be connected under the Contract shall be extended to the location shown and capped with a gasketed plug restrained against the leakage test pressure, and its end shall be marked at grade and recorded.

7.3 Connection to an Existing Main

7.3.1 The connection of a lateral to an existing main shall be made by the method indicated in the datasheet.
Lateral Connection to an Existing Mainselect
Manufactured saddle wye strapped and gasketed to the main
Gasketed insert tee fitting in a machine-cored opening
Cut-in wye fitting with flexible couplings
Core-drilled connection at an existing manhole
New manhole installed on the existing main
NOTE A saddle wye sits on a hole cut to the saddle manufacturer's template and is held by stainless straps with a gasket between saddle and pipe, and it is the connection most utilities permit on a PVC or clay main of any size; an insert tee is set in a cored hole and sealed by its own gasket, is the fastest tap on a main that cannot be taken out of service, and is limited to the branch sizes and main materials the fitting manufacturer publishes; a cut-in wye replaces a length of the main with a factory fitting between two flexible couplings, which gives the same connection a new main would have at the cost of taking the main out of service for the cut-in; a cored connection at an existing manhole avoids touching the main at all and is used where the lateral can reach a structure; a new manhole is cut into the main where the lateral is large, where several laterals will be collected, or where the Owner will not accept a tap on the main. (7.3.2)
7.3.3 Hand-cut openings finished with mortar, and any connection not listed in the datasheet, shall not be used on an existing main.
7.3.4 A connection to an existing main shall be made only with the utility owner's written approval where the utility owns the main, and only after the Contractor's flow management plan for that connection has been accepted.

7.4 Lateral Cleanouts

7.4.1 Cleanouts shall be provided on each lateral at the locations indicated in the datasheet, and at any additional location indicated on the plan and profile.
Lateral Cleanout Locationscheckbox
☑ At the property line, easement line, or right-of-way line
☑ At each change of direction exceeding 45 degrees
☐ At intervals not exceeding the maximum run the adopted plumbing code permits between cleanouts
☐ At the connection to the main, as a two-way cleanout
NOTE The cleanout at the five-foot point outside the foundation wall is furnished with the building drain under Sanitary Waste And Vent PipingSanitary Waste and Vent PipingResolves to the current adopted revision.sync/sanitary-waste-and-vent-piping and is not repeated here. (7.4.2)
NOTE The property-line cleanout is where a utility's responsibility for a lateral ends and the Owner's begins, and it is the access a utility crew uses to find which side of the line a blockage is on; a cleanout at each bend is what lets a cable follow the lateral without catching; a two-way cleanout at the main lets a crew rod toward the main and toward the building from one riser, and it is required by owners who televise every lateral at acceptance. (7.4.3)
7.4.4 Each cleanout shall consist of a wye or two-way cleanout fitting of the same material and joint type as the lateral, a riser of the same material brought to finished grade, and a gasketed or threaded plug.
7.4.5 The cleanout riser shall terminate at finished grade inside a cast iron or polymer concrete box with a cover marked SEWER, set in a concrete collar in paved and trafficked areas, and the box and cover shall be rated for the surface loading at that location.
NOTE A cleanout riser left as a bare capped pipe at grade is sheared by the first mower or plow to reach it, and the open riser then admits the stormwater the sewer was built to exclude. (7.4.6)

7.5 Termination at the Building Drain

7.5.1 The lateral shall connect to the building drain at the cleanout and transition fitting furnished five feet outside the foundation wall under Sanitary Waste And Vent PipingSanitary Waste and Vent PipingResolves to the current adopted revision.sync/sanitary-waste-and-vent-piping, at the invert elevation shown on the plan and profile, through a manufactured transition fitting listed for both pipe materials.
7.5.2 The Contractor shall verify the invert, size, and material of the building drain termination against the plan and profile before laying the lateral, and shall report any difference to the Engineer of Record before the lateral is laid.
NOTE The building drain invert is set by the plumbing contractor from the foundation plans, the lateral invert is set by the site contractor from the civil profile, and the two drawings are produced by different engineers from different datums; the five-foot point is where any disagreement between them becomes a pipe that runs uphill. (7.5.3)

8 Separation From Water Mains

8.1 Sanitary sewers, laterals, and force mains shall be separated from water mains, water services, and fire service mains by not less than the distances required by the state drinking-water regulation and the Authority Having Jurisdiction, and by not less than the distances in this standard.
8.2 A sewer or force main laid parallel to a water main shall be separated from it by not less than 10 ft horizontally, measured edge of pipe to edge of pipe.
8.3 Where a sewer or force main crosses a water main, the water main shall pass above the sewer with not less than 18 in. of vertical clearance between the outside of the water main and the outside of the sewer, and one full length of sewer pipe shall be centered on the crossing so that the sewer joints are as far from the water main as possible.
NOTE A sewer that leaks exfiltrates sewage into the soil, and a water main that is depressurized for a repair or a break draws from the soil around it; the separation rule keeps the one out of the reach of the other, and it is enforced by the state drinking-water program as a public-health rule rather than by the Engineer of Record as a preference. (8.4)
8.5 Where the horizontal separation or the vertical clearance cannot be met, or where the sewer must pass above the water main, the sewer shall be constructed through the affected length by the method indicated in the datasheet, and only with the written approval of the Authority Having Jurisdiction.
Sewer Construction Where Water Main Separation Cannot Be Metselect
Ductile iron pipe with joints centered on the crossing
AWWA C900 PVC pressure pipe with joints centered on the crossing
Butt-fused polyethylene pipe through the affected length
Concrete encasement of the sewer through the affected length
Sewer carried in a sealed casing pipe through the affected length
NOTE Each method substitutes a pressure-rated or jointless sewer for the gasketed gravity pipe through the length the regulation reaches: ductile iron and C900 PVC are the pressure pipes the regulations name and are jointed so that no joint falls within the water main's reach; fused polyethylene has no joint to fall there at all; concrete encasement protects a gravity joint by burying it in concrete, and it is the method a utility whose crews cannot handle a pressure pipe transition accepts; a casing pipe carries the sewer through a sleeve that can be sealed at both ends, and it is used where the crossing is under a structure or a roadway as well as near a water main. (8.6)
8.7 The affected length shall extend not less than 10 ft each side of the crossing centerline, or the full parallel length within 10 ft of the water main, unless the Authority Having Jurisdiction accepts a shorter length in writing.
8.8 The Contractor shall expose and record the elevation of every water main the sewer will cross before the sewer trench reaches it, and shall report to the Engineer of Record any crossing where the profile shows a clearance that the exposed water main does not permit.
8.9 Where the water main must be relocated, lowered, or replaced through a crossing to achieve separation, that work is governed by Water Distribution PipingSite Water Distribution PipingResolves to the current adopted revision.sync/water-distribution-piping and is coordinated with this standard at the crossing.

9 Sanitary Manholes

9.1 Manhole Construction

9.1.1 The construction of sanitary manholes shall be as indicated in the datasheet.
Sanitary Manhole Constructionselect
Precast circular reinforced concrete sections per ASTM C478
Fiberglass-reinforced polyester manhole per ASTM D3753
Polymer concrete manhole
Cast-in-place reinforced concrete
NOTE Precast concrete is the manhole the utility crew, the precaster, and the installer all know, available in every diameter and depth, heavy enough to resist flotation by its own mass, and attacked by the sulfuric acid that forms above the waterline unless it is lined. A fiberglass manhole is immune to that acid, arrives in one piece with no section joints to leak, weighs almost nothing, and so must be ballasted against flotation and protected from the traffic load a concrete barrel takes without thought. Polymer concrete carries the mass and stiffness of concrete with the acid resistance of a resin, at a higher price and from fewer suppliers, and it is the structure specified where the Owner wants no lining to maintain at a force main discharge. Cast-in-place concrete is used for a junction or a shape no precast section offers and is lined like precast. (9.1.2)
9.1.3 Brick and concrete masonry unit manholes shall not be used for new sanitary sewer construction unless the Contract Documents require them to match an existing structure being extended.
9.1.4 Fiberglass and polymer concrete manholes shall be set on a concrete base or ballast slab and anchored to it, and the manufacturer shall furnish the anti-flotation calculation for the empty manhole with the groundwater at Seasonal High Groundwater ElevationSeasonal High Groundwater ElevationParameterEach project supplies its own value.seasonal-high-groundwater-elevation.
9.1.5 Precast manhole sections shall be designed for the burial depth, the lateral soil and groundwater pressure, and the surface loading at the manhole location, and the design shall be stated on the shop drawings.

9.2 Concrete Manhole Interior Protection

9.2.1 Requirements in this article apply where a precast or cast-in-place concrete manhole is selected in the datasheet.
9.2.2 The interior protection of concrete sanitary manholes shall be as indicated in the datasheet.
Concrete Manhole Interior Protectionselect
No lining
100 percent solids epoxy lining
Polyurethane or polyurea lining
Embedded thermoplastic liner sheet cast into the concrete
Calcium aluminate mortar lining
9.2.3 The manhole receiving a force main discharge, the next manhole downstream of it, and any manhole at which a drop connection discharges shall be lined with one of the lined selections above, or shall be of fiberglass or polymer concrete, regardless of the selection made for the remainder of the system.
NOTE Sulfuric acid forms where hydrogen sulfide meets the moist concrete above the waterline, so the attack is worst at the top of the barrel and the underside of the cone, not at the bench, and it is worst where sewage is turbulent and septic: at a force main discharge, where sewage that has sat in the main for hours releases its sulfide all at once, and at a drop, where the fall strips gas from the flow. An ordinary gravity manhole on a short, well-sloped site sewer sees too little sulfide to need protection, which is why no lining is the position most site sewers take; a sprayed epoxy or polyurethane lining is the common protection and depends on surface preparation and thickness; an embedded liner sheet is anchored into the concrete at the plant and cannot delaminate, which is what recommends it for a deep or large structure; a calcium aluminate mortar resists the acid chemically rather than by sealing it out and is used where a cementitious surface is wanted. (9.2.4)
9.2.5 Where a lining is furnished, it shall cover the interior from the bench to the underside of the frame, including the cone and the chimney, and shall be holiday-tested before the manhole is shipped or, for a field-applied lining, before the manhole is placed in service.

9.3 Manhole Size

9.3.1 Minimum manhole inside diameter shall be not less than the value tabulated below for the largest pipe connecting to the structure.
Largest connecting pipe Minimum inside diameter
Up to 24 in. 48 in.
27 in. through 36 in. 60 in.
42 in. through 48 in. 72 in.
Larger than 48 in. As determined by the Engineer of Record for the pipe arrangement
9.3.2 Where pipes converge at a manhole at an included angle less than 90 degrees, where three or more pipes enter the manhole, or where an internal drop is furnished, the inside diameter shall be increased one tabulated size above the value required for the largest pipe.
NOTE The tabulated diameters are the sizes at which the wall openings, the gasket seats around them, and the bench between them will physically fit; an undersized manhole forces the openings to overlap, leaves no material between them to seal against, and cannot be benched to turn the flow. (9.3.3)
9.3.4 The Contractor shall verify manhole size against the pipe sizes and angles converging at that manhole before precast components are ordered.

9.4 Base and Top Configuration

9.4.1 The base configuration of precast manholes shall be as indicated in the datasheet.
Precast Manhole Baseselect
Monolithic precast base with the first riser cast integrally
Separate precast base slab with a gasketed riser joint
Cast-in-place base slab beneath precast risers
NOTE A monolithic base has no joint at the one elevation that is always below the water table, and it is what every precaster offers in the common diameters; a separate base slab lets the riser be rotated to the pipe angles after the slab is set and adds a gasketed joint at the floor; a cast-in-place base is used where the structure is set on rock or piles, or where the pipe arrangement cannot be cast at the plant. (9.4.2)
9.4.3 The top configuration of precast manholes shall be as indicated in the datasheet.
Precast Manhole Top Configurationselect
Eccentric cone
Concentric cone
Flat reinforced top slab
Derived — the manhole depth, the barrel diameter, and the clearance required above the largest pipe crown (by default)
NOTE A cone requires vertical room between the crown of the highest pipe and the underside of the frame to develop its taper, so shallow manholes and manholes with large pipes take a flat top slab, and the choice follows the geometry rather than a preference. (9.4.4)
9.4.5 Eccentric cones shall be oriented with the vertical face on the side opposite the largest inflow pipe, so that the access opening is above solid bench.

9.5 Section Joints

9.5.1 The joint between precast manhole sections shall be as indicated in the datasheet.
Precast Manhole Section Jointselect
Preformed flexible butyl joint sealant per ASTM C990
Confined O-ring rubber gasket per ASTM C443
Profile rubber gasket per ASTM C443
NOTE A butyl sealant is placed on the lower section and compressed by the weight of the upper one, forgives a joint surface that is not perfectly clean, and seals as long as the sections are brought together within the compression window; an O-ring is confined in a groove cast in the joint and seals under external head the way a pipe joint does, at the cost of joint surfaces that must be clean and a gasket that must not roll; a profile gasket seals the same way with a shape that tolerates more misalignment. Utilities that vacuum-test every manhole lean toward the gasketed joints, and precasters in some regions offer only one of the three. (9.5.2)
9.5.3 The external wrap at precast manhole section joints shall be as indicated in the datasheet.
External Joint Wrap at Section Jointsselect
Butyl rubber joint wrap at every section joint
Butyl rubber joint wrap at section joints below the seasonal high groundwater elevation
External sealing band per ASTM C877 at every section joint
Not provided
NOTE A wrap is a second seal outside the joint, and it is the one that stops the groundwater that finds a joint where the sealant did not compress; wrapping every joint is the practice of utilities that count infiltration at the plant, wrapping only the joints under water saves the labor above the water table, and a sealing band under ASTM C877 is the engineered form of the same thing for a structure that will be tested after backfill. (9.5.4)
9.5.5 Joint surfaces shall be clean and dry before the sealant or gasket is placed, and the upper section shall be lowered so that the sealant or gasket compresses uniformly around the full circumference.
9.5.6 The Contractor shall confirm that the upper section is fully seated before the lifting load is released.
9.5.7 Excess butyl sealant extruded into the interior of the structure shall be trimmed flush.

9.6 Pipe Connections to Manholes

9.6.1 The connection of each pipe entering or leaving a manhole shall be as indicated in the datasheet.
Pipe-to-Manhole Connectionselect
Cast-in resilient connector per ASTM C923
Field-cored opening with a boot-type resilient connector per ASTM C923
Flexible waterstop cast into a cast-in-place structure wall
NOTE Pipe and structure move differently under load and temperature, and a resilient connector is what absorbs that difference; a cast-in connector is set in the form at the plant at the angle and elevation the shop drawing shows and is the connection nearly every sanitary manhole is built with; a cored boot is cut into a finished barrel and serves a connection whose angle was not known when the barrel was cast, or a connection to an existing manhole; a flexible waterstop is the form the connector takes in a cast-in-place wall. (9.6.2)
9.6.3 Grouted rigid connections and mortared pipe penetrations shall not be used on a sanitary manhole.
9.6.4 Field-cored openings shall be cut with a diamond core barrel sized for the boot and the pipe outside diameter, shall not sever more reinforcement than the structure manufacturer permits, and shall be located and sized in accordance with the structure manufacturer's written instructions.
9.6.5 The Contractor shall submit the structure manufacturer's written acceptance for any field-cored opening within 12 in. of a structure joint or of another opening.
9.6.6 The annular space at every pipe connection shall be sealed on both the interior and exterior faces of the structure wall.
9.6.7 Where a pipe enters a manhole at an elevation above the bench without a drop assembly, the pipe shall be cut flush with the interior wall and the connector shall be finished so that no pipe projects into the manhole.

9.7 Bench and Channel

9.7.1 The bench and flow channel within each manhole shall be as indicated in the datasheet.
Manhole Bench and Channel Constructionselect
Cement mortar bench with a hand-troweled channel
Cast-in-place concrete bench with a formed channel
Factory-formed channel base section
NOTE A mortar bench is shaped in the field after the pipes are connected, so it matches the inverts as laid and costs a mason's morning per manhole; a formed concrete bench is placed where the mortar bench would crack, in a large manhole or under a heavy flow; a factory-formed base arrives with the channel cast to the shop drawing, is smoother than anything troweled in the field, and demands that the pipes be laid to the inverts the base was cast for. (9.7.2)
9.7.3 The channel shall be the full inside diameter of the outlet pipe at the invert, shall rise to not less than three-quarters of the outlet pipe diameter at the bench, and shall carry that section continuously from each inlet pipe to the outlet pipe without a step, lip, or change of section.
9.7.4 Channel inverts shall match the pipe inverts shown for that manhole.
NOTE A channel set below the pipe invert becomes a sump that fills with solids until it is the invert, and a channel set above the pipe invert holds sewage back into the upstream reach, where it goes septic; either error costs capacity that cannot be recovered without rebuilding the structure. (9.7.5)
9.7.6 The bench shall slope from the channel edge to the structure wall at not less than 1 in. per foot, and shall be finished smooth with no depression that holds sewage.
9.7.7 Where two or more pipes enter a manhole, the channel shall turn each inflow into the outflow direction on a swept curve rather than a square intersection.

9.8 Drop Connections

9.8.1 Where an inflow pipe invert is more than 24 in. above the outlet pipe invert, a drop connection shall be provided.
9.8.2 The drop connection configuration shall be as indicated in the datasheet.
Drop Connection Configurationselect
External drop outside the manhole barrel, encased in concrete
Internal drop inside the manhole barrel
Prefabricated drop assembly furnished with the manhole
NOTE An external drop keeps the barrel clear for entry and inspection and puts the falling sewage in a pipe outside the structure, where it cannot be seen once backfilled and cannot be cleared without excavating; an internal drop is visible and repairable from inside, takes up entry room, and exposes the barrel to the gas the fall releases, which is why the lining requirement in this standard reaches it; a prefabricated assembly is the internal drop as the manhole manufacturer builds it, bolted to the wall with the fittings matched to the barrel. (9.8.3)
9.8.4 Flow shall be conveyed from the inflow pipe to the channel invert without discharging onto the bench, and the drop pipe shall discharge in the direction of the outlet flow.
9.8.5 The inflow pipe shall also be connected to the manhole at its own invert through a resilient connector, so that the upper opening serves as the cleaning and inspection access to the drop.

9.9 Manhole Access

9.9.1 The access provision within sanitary manholes shall be as indicated in the datasheet.
Manhole Access Provisionselect
Copolymer polypropylene encased steel steps per ASTM C478
Cast-in steel steps with a protective coating
Fiberglass-reinforced polymer steps
Fixed ladder anchored to the barrel wall
No steps or ladder
NOTE Owners split on this decision: cast-in steps make routine inspection a one-person task, and they also become the liability when a corroded or loose step fails under a maintenance worker in a sulfide atmosphere that attacks every metal in it, which is why many owners now prohibit steps in sanitary manholes and enter them on portable equipment under a confined-space program. (9.9.2)
9.9.3 Where steps are provided, vertical spacing shall not exceed 16 in., the lowest step shall be not more than 24 in. above the bench, and the steps shall be aligned in a single vertical column beneath the access opening.
9.9.4 Where a fixed ladder is provided, its design shall be submitted to the Engineer of Record for acceptance before fabrication.
9.9.5 Manholes deeper than 20 ft shall be provided with a fixed ladder or an intermediate landing where the Authority Having Jurisdiction or the Owner's confined-space entry program under 29 CFR 1910.146 requires one.

10 Frames and Covers

10.1 Casting Alloy and Load Rating

10.1.1 Frames, covers, and lids shall be listed in accordance with AASHTO M306, which qualifies a casting by a proof load applied through a loading pad, with cracking or permanent deformation as cause for rejection.
10.1.2 Castings shall be free of cracks, cold shuts, blowholes, and inclusions, and mating surfaces shall be machined so that the cover seats without rocking.
10.1.3 The casting alloy shall be as indicated in the datasheet.
Casting Alloyselect
Gray iron per ASTM A48
Ductile iron per ASTM A536
Ductile iron cover set in a gray iron frame
Fiber-reinforced composite
NOTE Gray iron carries compression well and damps vibration, which is why it dominates street castings; ductile iron carries tension and impact, which matters where wheel loads exceed highway loading or where the casting takes repeated impact, and pairing a ductile cover with a gray iron frame puts the tougher metal only where the wheel actually lands; a composite cover is specified where theft of metal castings is a recurring problem, where the cover must not conduct, or where a lighter cover reduces the injury risk to maintenance staff, and it carries a lower impact rating than iron at the same proof load. (10.1.4)
10.1.5 The minimum casting load rating in vehicular areas shall be as indicated in the datasheet.
Minimum Casting Load Rating in Vehicular Areasselect
H-10 light vehicular loading
H-20 or HS-20 highway loading
H-25 or HS-25 highway loading
Aircraft or container-handling loading
10.1.6 Castings outside vehicular areas shall be rated for the loads actually imposed at that location, and shall be not less than H-10 rated wherever a fire lane, service drive, or maintenance vehicle route crosses the manhole.
10.1.7 The Contractor shall report to the Engineer of Record any location where a casting shown as pedestrian-rated falls on a fire lane, a service vehicle route, or the route a vacuum truck will take to service the sewer.
NOTE The vacuum truck is the load case a sanitary manhole in a lawn is most often sized without: the surface reads as pedestrian, the casting is specified to match, and the manhole is then driven over by the heaviest vehicle on the site every time the sewer is cleaned. (10.1.8)

10.2 Cover Ventilation, Restraint, and Legend

10.2.1 The ventilation of sanitary manhole covers shall be as indicated in the datasheet.
Manhole Cover Ventilationradio
● Solid cover without vent holes
○ Vented cover
NOTE Every vent hole in a sanitary cover is an inflow path at every storm, so the solid cover is the position nearly every sanitary system takes; a vented cover is specified by owners who want the sewer to breathe at the manhole to relieve the pressure a surcharge or a force main discharge builds, and it is paired with an inflow dish where it is used. (10.2.2)
10.2.3 The restraint and sealing of manhole covers shall be as indicated in the datasheet.
Manhole Cover Restraintselect
Standard seated cover without restraint
Gasketed self-sealing cover
Bolted cover with stainless steel fasteners
Locking or pick-resistant cover
10.2.4 Covers on manholes within a flood hazard area, at sag locations subject to ponding, on reaches designed to surcharge, and at a force main discharge shall be gasketed or bolted so that surcharge pressure cannot displace them and ponded water cannot enter around them.
10.2.5 Bolted covers shall use stainless steel fasteners.
NOTE Carbon steel fasteners in a sewer manhole, where the atmosphere is humid and acidic, seize within a few seasons, and the cover then has to be cut open by the crew that came to inspect it. (10.2.6)
10.2.7 The legend cast into sanitary manhole covers shall be as indicated in the datasheet.
Sanitary Manhole Cover Legendselect
SANITARY SEWER
SANITARY
SEWER
S
NOTE The legend is what keeps a storm crew out of a sanitary manhole and a sanitary crew from flushing into the storm system, and the full words are the position most owners take; the shorter legends are the patterns some utilities have cast for decades and keep for consistency with the structures around them. (10.2.8)
10.2.9 Where the utility owner requires a specific cover pattern and legend for structures it will accept, that pattern and legend shall govern over the datasheet selection for those structures.

10.3 Adjustment to Grade and Inflow Protection

10.3.1 The method of adjusting the casting to finished grade shall be as indicated in the datasheet.
Casting Grade Adjustment Methodselect
Precast concrete grade rings set in butyl sealant or mortar
Polyethylene or recycled rubber grade rings
Mortared brick courses
Custom-height precast riser section
Frame set directly on the structure without adjustment
NOTE Precast rings are the adjustment every precaster supplies and every crew knows; polymer rings are lighter, do not crack under traffic, and seal to each other with no mortar joint to leak, which is why owners who chase inflow at the chimney specify them; brick courses are the oldest method and the leakiest, admitted by owners whose crews rebuild chimneys that way; a custom riser section replaces the stack with one piece and one joint; and no adjustment is the position where the cone is cast to the rim elevation. (10.3.2)
10.3.3 The maximum height of the grade adjustment stack shall be as indicated in the datasheet.
Grade Adjustment Stack Heightrange
Not more than
in
68121624
10.3.4 Where the adjustment required at a manhole exceeds the maximum stack height, a custom-height riser section shall be furnished rather than additional rings.
NOTE Every ring in the stack adds two joints, and each joint is a hinge under traffic and an inflow path under ponded water; a tall stack works loose, admits water behind the frame, and settles as a unit, taking the pavement around the casting with it. (10.3.5)
10.3.6 The frame shall be set on a continuous bed of butyl sealant or mortar on the top ring, with its inside face flush with the inside face of the structure and no mortar projecting into the structure.
10.3.7 The inflow protection at the frame and chimney of each manhole shall be as indicated in the datasheet.
Inflow Protection at the Frame and Chimneycheckbox
☐ Internal flexible chimney seal spanning the frame and the cone
☐ External chimney seal wrapped over the frame, rings, and cone
☐ Inflow dish insert beneath the cover
NOTE The chimney, the stack of rings between the cone and the frame, is the part of a manhole that moves with the pavement and the part most often rebuilt, and it is where a sewer that passed its vacuum test admits the inflow the utility later meters; an internal seal is a rubber sleeve banded to the frame and to the cone that bridges the whole stack and is installed and replaced from inside, an external seal does the same from the outside and is installed before backfill, and an inflow dish sits in the frame under the cover and catches what comes through the pick holes and the seat, with a small drain to relieve a surcharge. (10.3.8)
10.3.9 Where a chimney seal is provided, it shall be installed in accordance with the seal manufacturer's instructions after the frame is set to final grade, and shall be included in the vacuum test of the manhole where that test is performed after the frame is set.

11 Trench Excavation and Foundation

11.1 Trench Dimensions

11.1.1 Trench excavation, sloping, benching, shoring, and worker protection shall conform to EarthworkEarthworkResolves to the current adopted revision.sync/earthwork and Excavation Support And DewateringExcavation Support and DewateringResolves to the current adopted revision.sync/excavation-support-and-dewatering, and to 29 CFR 1926 Subpart P.
11.1.2 Trench width at the pipe springline shall be not less than the pipe outside diameter plus 16 in., and not less than the minimum width published by the pipe manufacturer for the pipe size supplied.
11.1.3 Trench width at the pipe springline shall not exceed the maximum trench width used in the design of a rigid pipe for that reach.
NOTE Trench width matters in both directions and for opposite reasons: too narrow and there is no room to work embedment into the haunch, which is where a flexible pipe gets its support; too wide and a rigid pipe carries more of the soil prism above it than the installation type assumed. (11.1.4)
11.1.5 The trench bottom shall be excavated to the design pipe invert less the bedding thickness, on a uniform grade matching the design slope, without dips, high spots, or reverse gradient.
11.1.6 Where the trench bottom is over-excavated below the design bedding elevation, the over-excavation shall be brought back to grade with compacted bedding material at the Contractor's expense, and shall not be brought back to grade with excavated native material.

11.2 Trench Foundation

11.2.1 The trench bottom of every reach shall be observed by the geotechnical engineer of record or the Owner's designated inspector, and released in writing, before bedding is placed.
11.2.2 Pipe shall not be placed on a trench bottom that is soft, pumping, frozen, or covered with standing water, and shall not be placed on disturbed or loose material.
11.2.3 Where the trench bottom is unsuitable, the foundation shall be stabilized as indicated in the datasheet before bedding is placed.
Trench Foundation Stabilization Where the Bottom Is Unsuitableselect
Over-excavate and replace with compacted crushed stone
Over-excavate, place a separation geotextile, and replace with crushed stone
Over-excavate and replace with controlled low-strength material
Geogrid reinforcement beneath a crushed stone working platform
11.2.4 The depth of over-excavation and the stabilization method at each occurrence shall be as directed by the geotechnical engineer of record, and shall be documented in the project record for that reach.
NOTE The whole load path assumed for the pipe runs through the bedding into the trench bottom, so a soft foundation does not merely settle: it lets the bedding deform, which unloads the haunch, which lets the pipe deflect and the joints open at the low point of the reach, and on a sanitary sewer that low point is a belly that holds sewage and goes septic. Crushed stone alone is the usual repair in a firm but wet bottom; the geotextile is added where the bottom is fine-grained and would pump into the stone; controlled low-strength material is used where the over-excavation is deep and the trench is narrow; geogrid under a working platform is the choice over a soft bottom too extensive to replace. (11.2.5)
11.2.6 Where crushed stone is placed against a fine-grained trench bottom or fine-grained trench walls, a separation geotextile shall be placed between them.

11.3 Groundwater and Flotation

11.3.1 Trenches whose bottom lies below Seasonal High Groundwater ElevationSeasonal High Groundwater ElevationParameterEach project supplies its own value.seasonal-high-groundwater-elevation shall be dewatered continuously, by the sump pumping EarthworkEarthworkResolves to the current adopted revision.sync/earthwork provides or by a designed system under Excavation Support And DewateringExcavation Support and DewateringResolves to the current adopted revision.sync/excavation-support-and-dewatering, from before excavation of the pipe zone until sufficient backfill is in place to resist flotation.
11.3.2 The groundwater level shall be maintained not less than 12 in. below the trench bottom throughout pipe laying, embedment placement, and embedment compaction.
11.3.3 Dewatering discharge shall be conducted through the sediment controls required by Erosion And Sediment ControlErosion and Sediment ControlResolves to the current adopted revision.sync/erosion-and-sediment-control, shall comply with the project's discharge permit, and shall not be routed into the sanitary sewer, new or existing.
NOTE Empty thermoplastic pipe below the water table will float, and a floated pipe does not simply rise: it lifts between fixed structures into a reverse grade, opens joints at the ends of the floated segment, and displaces the embedment that was holding it. (11.3.4)
11.3.5 Where dewatering is interrupted before sufficient cover is placed, the Contractor shall ballast the pipe with water or place additional cover before the groundwater is allowed to recover.

12 Pipe Embedment and Backfill

12.1 Embedment Material

12.1.1 The embedment material for flexible pipe, comprising the bedding, the haunch, and the initial backfill to the top of the pipe zone, shall be as indicated in the datasheet.
Flexible Pipe Embedment Material Classselect
ASTM D2321 Class IA open-graded clean angular crushed stone
ASTM D2321 Class IB dense-graded processed angular stone and sand
ASTM D2321 Class II clean coarse-grained sand and gravel
ASTM D2321 Class III coarse-grained soil with fines
NOTE Class IA material develops its support on placement and light working rather than on compactive effort, which is what makes it forgiving in the haunch, the one location under a flexible pipe that no compactor can reach, and it is the embedment most sewer specifications and most utilities require; Class IB and Class II materials will reach the same support but only if they are placed in thin lifts and actually compacted there, and Class II sand is the embedment of regions where crushed stone is not local; Class III is admitted where the native soil is granular and the Owner accepts a higher deflection risk for a lower embedment cost. (12.1.2)
12.1.3 Class IV and Class V materials as classified by ASTM D2321, including silt, clay, and organic soils, shall not be used as embedment for flexible pipe.
12.1.4 Crushed concrete, slag, and any aggregate containing particles larger than 1 in. shall not be used as embedment in contact with plastic pipe.
12.1.5 The bedding course thickness below the pipe shall be as indicated in the datasheet.
Bedding Course Thickness Below the Piperange
Not less than
in
34691218
12.1.6 The bedding course thickness shall be not less than 6 in. where the trench bottom is rock, cemented material, or a stabilized foundation course.
12.1.7 Bedding beneath rigid pipe shall be shaped to the bottom of the pipe so that the pipe bears uniformly along its full length, and bell holes shall be excavated at each joint so that no pipe bears on its bell.
12.1.8 Bedding beneath flexible pipe shall be placed and struck level to the design grade, and the pipe shall be supported by embedment worked into the haunch after the pipe is laid rather than by a shaped bed.

12.2 Placement and Compaction

12.2.1 Embedment shall be placed simultaneously on both sides of the pipe and shall be worked into the haunch beneath the pipe springline by shovel slicing or rodding before compaction of the lift.
12.2.2 Embedment shall be placed in lifts not exceeding 8 in. of loose thickness up to the top of the pipe zone.
NOTE The pipe zone extends from the top of the bedding to a plane 12 in. above the crown of the pipe. (12.2.3)
12.2.4 The minimum compaction of Class IB, Class II, and Class III embedment materials shall be as indicated in the datasheet.
Embedment Compaction for Class IB, II, and III Materialsrange
Not less than
% of maximum standard Proctor dry density
859095100
12.2.5 Class IA embedment shall be placed and consolidated by working and light tamping, and a Proctor-referenced compaction requirement shall not be applied to it.
NOTE An open-graded angular stone has no meaningful Proctor curve, so a percent-of-Proctor acceptance criterion cannot be tested on it; acceptance is by placement method, lift thickness, and the working of the haunch. (12.2.6)
12.2.7 Compaction equipment shall not be operated directly over the pipe until at least 12 in. of compacted cover is in place above the crown.
12.2.8 Hand-operated plate compactors or rammers shall be used within the pipe zone.
NOTE A vibratory roller delivers a dynamic load far above the wheel load the pipe was designed for, and applying it over thin cover deflects a flexible pipe or cracks a rigid one at the moment when nothing above the pipe is yet distributing the load. (12.2.9)

12.3 Cover Limits

12.3.1 The minimum cover over the crown of the pipe shall be as indicated in the datasheet.
Minimum Cover Over the Pipe Crowntext
Enter value...
in
Derived — the pipe material and dimension ratio or strength class, the design live load at that location, and the minimum cover published for that combination in the product standard or the manufacturer's fill height tables (by default)
12.3.2 Cover over the pipe crown shall not exceed the maximum fill height published for the pipe material, class or stiffness, and installation type of that reach.
12.3.3 Where the profile shows cover at any point below the derived minimum or above the published maximum for the pipe indicated, the Contractor shall report the condition to the Engineer of Record before installing that reach.
12.3.4 Construction traffic shall not cross a reach until the cover in place meets the minimum cover for construction loading published by the pipe manufacturer, and the Contractor shall provide temporary cover, matting, or bridging at construction crossings where it does not.
NOTE The construction load case usually governs, not the finished condition: the pipe reaches its design cover only after paving, while the loaded haul trucks cross it during backfill, when the cover is thinnest. (12.3.5)

12.4 Final Backfill

12.4.1 Trench backfill above the pipe zone shall conform to the requirements of EarthworkEarthworkResolves to the current adopted revision.sync/earthwork for the area in which the trench falls, and this standard does not restate those requirements.
12.4.2 Trench backfill compaction shall be tested at the frequency required by EarthworkEarthworkResolves to the current adopted revision.sync/earthwork, and material failing that test shall be removed or scarified and recompacted at the Contractor's expense.
NOTE Backfill in the upper portion of a utility trench is the single most common source of the longitudinal pavement cracking and dishing that appears over sewer trenches in the first years of service, and it is the part of the sewer scope least likely to be inspected, because the pipe below it has already passed its tests. (12.4.3)

13 Pipe Installation

13.1 Laying and Alignment

13.1.1 Pipe shall be laid beginning at the downstream end of each reach and progressing upstream, with bells facing upstream.
NOTE Laying upstream places the spigot into the bell in the direction of flow, so the joint presents no shoulder to catch solids, and it leaves the home mark visible from the upstream side where the crew is working. (13.1.2)
13.1.3 The method of verifying pipe alignment and grade shall be as indicated in the datasheet.
Pipe Alignment and Grade Verification Methodselect
Pipe laser set to the design invert and slope
Robotic total station
Transit and offset grade stakes
String line and batter boards
NOTE A pipe laser set in the downstream manhole projects the design grade down the pipe and is checked at every joint by a target, which is why it has become the method for nearly every gravity sewer; a robotic total station checks each joint against the design model and is the method where the laser line is blocked by a curve or a long reach; grade stakes and a transit are the method where neither instrument is available and the reach is short; a string line on batter boards is the oldest method and the least precise, and it is admitted on a shallow lateral where the slope is steep enough to forgive it. (13.1.4)
13.1.5 Each pipe section shall be brought to the design line and grade before the joint is closed.
NOTE Once a gasketed joint is home, correcting alignment requires disassembling the joint, so the check belongs before the joint is made rather than after. (13.1.6)
13.1.7 The as-laid invert shall be verified at each joint, and any deviation from the design invert exceeding the pipe manufacturer's installation tolerance shall be reported to the Engineer of Record before embedment is placed over that joint.
13.1.8 Joint deflection shall not exceed the deflection published by the joint manufacturer for that pipe size and joint type, and horizontal curves shall be made only where the plan and profile shows them.
13.1.9 The completed reach between structures shall hold a uniform grade with no sag, and shall show a full circle of light when lamped from structure to structure.
NOTE A sag in a sanitary sewer holds sewage that goes septic, releases sulfide into the next manhole, and collects the grease and grit that become the first blockage; the sag is created during laying and can only be caught during laying, because once the reach is backfilled and paved there is no way to correct one short of excavating the reach. (13.1.10)

13.2 Joint Assembly

13.2.1 The bell and gasket seat of each pipe shall be cleaned of soil and debris immediately before the joint is assembled.
13.2.2 Lubricant supplied or approved in writing by the pipe manufacturer shall be applied to the gasket and the spigot in accordance with the manufacturer's instructions.
13.2.3 Petroleum-based lubricants, grease, and detergents shall not be applied to elastomeric gaskets.
NOTE A petroleum lubricant swells and softens most elastomeric gasket compounds, and the joint that passed its test on the day it was made loses its seal over the following months as the compound degrades. (13.2.4)
13.2.5 The spigot shall be advanced until the home mark reaches the bell face or until the spigot shoulder contacts the bell, whichever the joint design specifies, and shall not be driven past that point.
NOTE Over-insertion rolls or pinches the gasket out of its seat, which produces a leak path that no external sealing can reliably close. (13.2.6)
13.2.7 Joints shall be assembled with equipment appropriate to the pipe weight, and pipe shall not be pulled home with excavator bucket pressure applied directly to the pipe barrel or bell.

13.3 Cutting Pipe

13.3.1 Field cuts shall be square to the pipe axis, and the cut spigot end shall be deburred and chamfered so that the gasket enters without rolling.
13.3.2 Reinforced concrete and vitrified clay pipe shall be cut with a diamond saw or a pipe cutter the manufacturer publishes, and shall not be cut by flame, impact, or percussion methods.
13.3.3 Thermoplastic pipe shall be cut with a saw or pipe cutter producing a clean perpendicular face, and profile-wall pipe shall be cut at the location within the profile specified by the pipe manufacturer.
13.3.4 A cut end that has not been rebuilt to the joint geometry the gasket needs shall not be used at a gasketed joint, and the pipe shall be replaced or a manufactured coupling shall be used.

13.4 Transitions and Couplings

13.4.1 The method of joining dissimilar pipe materials, field cut-ins, and connections to existing pipe shall be as indicated in the datasheet.
Joining Method at Material Transitionsselect
Manufactured transition coupling listed for the specific outside diameter pair
Compression repair coupling with a stainless steel shear band
Transition through a manhole
NOTE A transition coupling is an elastomeric sleeve molded to the two outside diameters it joins, with bands that compress each end, and it is the connection every lateral tie-in and every change of material is made with; a shear-banded repair coupling adds a stainless shell that keeps the two pipes in line under load and is the coupling for a cut-in on a main or a joint under a pavement; a transition through a manhole avoids a buried coupling entirely and is the method where a structure is already within reach. (13.4.2)
13.4.3 Transition couplings shall be sized to the actual outside diameters of both pipes.
NOTE Concrete, clay, solid-wall PVC, polyethylene, and ductile iron pipe of the same nominal size have different outside diameters, so a coupling sized from the nominal size over-compresses one gasket and under-compresses the other, and the joint leaks from the day it is buried. (13.4.4)
13.4.5 Cast-in-place concrete collars shall not be used as the sole joint at a transition on a sanitary sewer.

13.5 Locating and Identification

13.5.1 The provision for locating buried nonmetallic sanitary sewer and force main shall be as indicated in the datasheet.
Locating Provision Over Nonmetallic Pipeselect
Detectable marking tape above the pipe zone
Tracer wire attached along the pipe
Detectable marking tape and tracer wire
No locating provision
NOTE A gravity sewer can be located from its manholes with a sonde, which is why some owners furnish no locating provision on it; a force main has no manholes, runs where the profile needed it to rather than in a straight line between structures, and is the pipe a one-call locator cannot find without a tracer wire, which is why owners who furnish nothing on the gravity sewer still furnish tracer wire on the force main. Marking tape warns the excavator who has already dug to it, tracer wire finds the pipe before the excavator starts, and the two together are the position most utilities take on every nonmetallic pressure main. (13.5.2)
13.5.3 Where tracer wire is provided, it shall be continuous through each reach, shall be brought to an accessible termination inside a structure or a tracer wire access box at each end of the reach and at every air valve vault, and shall be tested for continuity before acceptance.
13.5.4 Where detectable marking tape is provided, it shall be placed 12 in. to 18 in. above the pipe crown, centered over the pipe, and shall be green and legible as sanitary sewer.

13.6 Connections to Existing Sewers

13.6.1 The Contractor shall coordinate every connection to an existing or public sewer with the utility owner and the Engineer of Record before the work, and shall confirm the connection method, flow management during the cut-in, and the inspection to be witnessed.
13.6.2 The Contractor shall verify the invert, size, material, and condition of the existing pipe or structure at each point of connection before ordering materials for that connection.
13.6.3 Connections into an existing manhole shall be made by core drilling with a diamond core barrel and a resilient connector, and shall not be made by breaking out the structure wall.
13.6.4 The bench and channel of an existing manhole receiving a new connection shall be rebuilt to turn the new flow into the outlet as this standard requires for a new manhole.
13.6.5 Cut-ins on an in-service sewer shall be made only with the utility owner's written approval, only after the Contractor's flow management plan for that cut-in has been accepted, and with the flow plugged upstream and bypass pumped around the connection for the duration of the work.
13.6.6 Sewage released during a connection shall be contained and recovered, and the Contractor shall report any release that reaches a storm drain, a watercourse, or the ground surface to the Owner and the Authority Having Jurisdiction without delay and shall bear the cost of the cleanup and of any penalty assessed for it.
13.6.7 The new sewer shall be plugged at its downstream end with a restrained, gasketed plug from the time the connection is made until the new sewer has been tested, cleaned, and accepted, so that construction water and debris do not enter the existing system.
13.6.8 The point of connection to the public sewer shall be as indicated on the civil utility plan.

14 Sewage Force Mains

14.1 Force Main Boundary

14.1.1 Requirements in this section apply where the site includes a sewage force main from a lift station to the gravity sewer.
NOTE The force main begins at the discharge connection at the station limit, which Packaged Pump StationsPackaged Pump and Lift StationsResolves to the current adopted revision.sync/packaged-pump-stations defines and furnishes with the adapter the transition to the force main material requires, and ends at the receiving manhole, and the station manufacturer's discharge connection size and material shall be confirmed against the force main before either is installed. (14.1.2)
NOTE The design flow, the design working pressure, the surge allowance, and the force main size are established by the civil engineer of record in the lift station hydraulic calculations and recorded on the force main profile; this standard defers each of those values to the drawings and does not select them. (14.1.3)
14.1.4 The force main alignment, size, profile, and the location of every fitting, air valve, isolation valve, and cleaning connection shall be as indicated on the force main plan and profile.

14.2 Force Main Pipe Material

14.2.1 The force main pipe material shall be as indicated in the datasheet.
Force Main Pipe Materialselect
Butt-fused polyethylene pressure pipe per AWWA C906 or ASTM F714
Gasketed PVC pressure pipe per AWWA C900
Fusible PVC pressure pipe per AWWA C900
Ductile iron pipe per AWWA C151 with restrained joints
NOTE Fused polyethylene is one continuous pipe with no gasketed joint to exfiltrate sewage or admit groundwater, tolerates ground movement and surge better than any other material, and is pulled through a directional drill, and its costs are fusion labor, a lower pressure rating at the same wall than PVC, and a wall that must be thick enough to hold vacuum on draindown. Gasketed C900 PVC is the lowest first cost force main, jointed like the water main the crew just laid, and every gasketed joint is a joint that must be restrained at every fitting and that can leak sewage into the soil if the restraint fails. Fusible PVC carries the strength of PVC with the jointless string of polyethylene and is the pipe of a PVC directional-drill pull. Ductile iron carries the highest pressure and the heaviest surface load, is restrained with the gaskets and glands every utility stocks, and depends on its lining in sewage service, which the ductile iron article in this standard governs. (14.2.2)
14.2.3 The force main pressure class or dimension ratio shall be as indicated in the datasheet.
Force Main Pressure Class or Dimension Ratiotext
Enter value...
Per drawings — the force main profile and the lift station hydraulic calculations (deferred by default)
14.2.4 The pressure class or dimension ratio furnished shall be not less than that required for the design working pressure plus the surge allowance stated in the hydraulic calculations, and for a polyethylene force main not less than that required to resist full vacuum at the highest point of the profile when the main drains after the pumps stop.
14.2.5 Polyethylene force main pipe shall be PE4710, joined by butt fusion in accordance with ASTM F2620 with a data log recorded for every joint, and electrofusion couplings shall be used only where a butt fusion machine cannot be placed.
14.2.6 PVC force main pipe shall conform to AWWA C900 with the dimension ratio indicated, with gaskets conforming to ASTM F477 on gasketed pipe, and shall be installed in accordance with AWWA C605 and AWWA M23.
14.2.7 Ductile iron force main pipe shall conform to the ductile iron article of this standard, shall be furnished with restrained joints throughout unless the thrust restraint method in the datasheet provides otherwise, and shall be installed in accordance with AWWA C600.
14.2.8 Fittings on a PVC or polyethylene force main shall be ductile iron fittings conforming to AWWA C110 or AWWA C153 with the sewage-service lining selected in this standard, or molded or fabricated fittings of the pipe material rated for the same pressure as the pipe.

14.3 Thrust Restraint

14.3.1 Every fitting, valve, dead end, and change of direction or size on the force main shall be restrained against the thrust developed at the test pressure by the method indicated in the datasheet, and the restraint shall be shown in the thrust restraint calculation submitted under this standard.
Force Main Thrust Restraint Methodselect
Restrained joints throughout the force main
Restrained joints for the calculated length each side of each fitting
Concrete thrust blocks bearing on undisturbed soil
Fused pipe with restrained transition fittings only
NOTE Restraining every joint makes the whole main one continuous member and is the method of utilities that will never again rely on soil they cannot see; restraining the calculated length each side of each fitting is the engineered minimum and depends on the soil bearing and friction values the calculation assumed being the ones in the trench; a thrust block transfers the thrust to undisturbed soil behind the fitting, costs nothing but concrete, and fails when the soil behind it is later excavated for another utility; a fused main needs no restraint along its length and is restrained only where it transitions to a gasketed material or a flanged valve. (14.3.2)
14.3.3 Restrained joint devices shall be of the type the pipe manufacturer qualifies for the pipe furnished, and serrated gland restraints shall not be used on polyethylene pipe without the internal stiffener the restraint manufacturer requires.
14.3.4 Thrust blocks shall bear on undisturbed soil, shall be sized for the soil bearing value stated in the geotechnical report, and shall be placed so that the fitting joints and bolts remain accessible.
14.3.5 Where a thrust block is selected and the soil behind the fitting has been disturbed by another excavation, the Contractor shall report the condition to the Engineer of Record and shall restrain the fitting by restrained joints at the Contractor's expense where the disturbance results from the Contractor's work.

14.4 Air Release at High Points

14.4.1 Air valves shall be provided at the high points of the force main profile, of the type indicated in the datasheet.
Air Valve Type at Force Main High Pointsselect
Combination air valve for wastewater service per AWWA C512
Air release valve for wastewater service per AWWA C512
No air valves, profile laid on a continuous rise to the discharge
NOTE Air collects at every high point of a force main, reduces the flow area until the pump is working against a head the design never counted, and is the usual cause of a station that cannot make its flow a year after startup. A combination valve releases air under pressure and admits air on draindown, so the main cannot collapse under vacuum when the pumps stop, and it is the valve nearly every high point gets; an air release valve alone vents air under pressure and is used where the pipe wall holds vacuum without help and the owner wants the smaller valve; no valve at all is the position for a short main laid on a continuous rise from the station to the discharge, where there is no high point for air to collect at and every bubble reaches the manhole on its own. (14.4.2)
14.4.3 Air valves for wastewater service shall be of the elongated-body wastewater pattern with a backwash connection and an isolation valve below the air valve, and shall not be a water-service air valve.
NOTE A water-service air valve has a short body and a float that sits in the liquid, and in sewage the float fouls with grease and rags within weeks; the wastewater pattern keeps the float above the sewage in a tall body and gives the operator a flushing connection to clear it without removing it. (14.4.4)
14.4.5 Each air valve shall be installed in a precast concrete or fiberglass vault with a hatch or cover sized for valve removal, a vent to atmosphere terminated above grade with an insect screen, and a drain, set at the location on the force main profile.
14.4.6 Air valve vaults shall be located outside vehicular areas where the profile permits, and where a vault must be in a vehicular area its cover shall carry the load rating this standard requires for castings there.

14.5 Cleaning Access and Isolation

14.5.1 Cleaning access to the force main shall be as indicated in the datasheet.
Force Main Cleaning Accessselect
Pig launch and receive connections at the station and at the discharge
Flushing connections at the air valve vaults and the low points
Not provided
NOTE Grease and struvite build on the wall of a sewage force main until the friction loss exceeds what the pump can overcome, and the only cure short of replacement is to clean the main; pig connections let a foam pig be driven through the main from the station to the discharge and are the access of long mains and of owners who clean on a schedule; flushing connections at the vaults let a crew flush a section from a hydrant or a truck and are the access of short mains; no access is the position for a main short enough and fast enough that its velocity scours it. (14.5.2)
14.5.3 Isolation valves on the force main beyond the station limit, where the force main profile shows them, shall be eccentric plug valves conforming to AWWA C517, buried with an extension stem and valve box or installed in a vault, and installed with the seat on the station side so that line pressure seats the plug.
14.5.4 The valve or the station's own discharge valves that a crew will close to isolate a section of the force main for cleaning or repair shall be identified on the record drawings.

14.6 Force Main Depth and Routing

14.6.1 The force main shall be installed with its crown below Frost DepthFrost DepthParameterEach project supplies its own value.frost-depth and with not less than the minimum cover published for the pipe material and the live load at that location, whichever is greater.
NOTE A force main holds standing sewage between pump cycles, so unlike a gravity sewer it will freeze if it is above the frost line, and a frozen force main is a station in alarm with nowhere to pump to. (14.6.2)
14.6.3 The force main shall be laid to the profile shown so that every high point carries an air valve and every low point is drained toward an air valve vault or the station, and the Contractor shall not create an intermediate high point by deviating from the profile.
14.6.4 Where the force main crosses a water main, the separation requirements of this standard apply, and the force main shall be treated as a sewer under them.
14.6.5 The embedment, trench foundation, groundwater control, and backfill requirements of this standard apply to the force main, with the embedment class selected for the pipe material furnished.

14.7 Discharge Manhole

14.7.1 The force main shall discharge into the receiving manhole through a resilient connector, with the invert of the force main at the manhole wall not more than 12 in. above the channel invert, and shall be turned into the direction of the outlet flow by a channel formed for it.
NOTE A force main that discharges high on the barrel or across the flow falls onto the bench, strips the sulfide out of sewage that has gone septic in the main, and fills the manhole and the next one downstream with the gas that eats their concrete; the low, swept entry puts the flow into the channel with the least turbulence the geometry allows. (14.7.2)
14.7.3 The receiving manhole and the next manhole downstream shall be lined or of corrosion-resistant construction as the manhole protection article of this standard requires, and the receiving manhole cover shall be gasketed or bolted as the cover restraint article requires.
14.7.4 The gravity reach downstream of the discharge manhole shall be of a material permitted in the datasheet and sized on the plan and profile for the pumped flow, and a reach shown smaller than the force main shall be reported to the Engineer of Record before it is laid.

15 Testing and Acceptance

15.1 Pipe Leakage Testing

15.1.1 Every reach of gravity sewer, from manhole to manhole, and every lateral shall be tested for leakage by the method indicated in the datasheet.
Gravity Sewer Leakage Test Methodselect
Low-pressure air test per ASTM F1417, ASTM C924, or ASTM C828 for the pipe material
Hydrostatic exfiltration test per ASTM C969
Infiltration measurement per ASTM C969
Joint-by-joint packer test per ASTM C1103
NOTE The low-pressure air test is run in minutes with a compressor and a gauge, needs no water and no disposal, and is the acceptance test nearly every sewer specification and utility requires on a gasketed sewer; its procedure is the standard for the pipe material, F1417 for plastic, C924 for concrete, and C828 for clay. An exfiltration test fills the reach with water to a head above the crown and measures the loss, which takes hours and a water source, and is used where the owner's criterion is written in gallons per inch-mile per day; infiltration measurement is only possible where groundwater stands above the crown for the full reach at the time of test, and it measures the thing the owner actually cares about; a packer test isolates and tests one joint at a time from inside the pipe and is used on a large-diameter reach that cannot be plugged and pressurized as a unit. (15.1.2)
15.1.3 Leakage testing shall be performed after embedment is complete and before final backfill closes the trench above the pipe zone.
15.1.4 Test plugs and end caps shall be rated for the test pressure and shall be mechanically restrained against blow-out before the reach is pressurized.
NOTE A test plug that releases at test pressure in a large pipe leaves the pipe end at a speed that has killed test crews; restraint and a cleared work area are not optional refinements of the procedure. (15.1.5)
15.1.6 Where groundwater stands above the pipe crown, the air test gauge pressure shall be increased by 0.433 psi for each foot of water above the crown, and the elevation used shall be measured at the time of test rather than taken from Seasonal High Groundwater ElevationSeasonal High Groundwater ElevationParameterEach project supplies its own value.seasonal-high-groundwater-elevation.
15.1.7 Where a hydrostatic exfiltration or infiltration test is selected, the maximum allowable leakage shall be as indicated in the datasheet.
Allowable Exfiltration or Infiltrationrange
Not more than
gal per in. of diameter per mile per day
2550100200500
NOTE The allowable leakage is the owner's number, not the pipe's: a gasketed sewer that passes an air test leaks far less than any of the setpoints, and the value is set by what the receiving utility bills for infiltration and what the state regulation permits, which is why no value is asserted here and the common regulatory ceilings appear among the setpoints. (15.1.8)
15.1.9 Laterals shall be tested with the main where the lateral is complete to its termination when the main is tested, and otherwise shall be tested separately from the main to the same criterion after the lateral is laid.
15.1.10 A reach that fails the leakage test shall be repaired and retested until it passes, and the Contractor shall bear the cost of the repair and of every retest of that reach.
15.1.11 The Contractor shall identify and correct the cause of a failure before retesting, and shall record both the failure and the passing retest.

15.2 Manhole Leakage Testing

15.2.1 Each sanitary manhole shall be tested for leakage by the method indicated in the datasheet.
Manhole Leakage Test Methodselect
Negative air pressure vacuum test per ASTM C1244
Hydrostatic exfiltration test
Visual inspection for infiltration only
No manhole leakage test
NOTE The vacuum test is the test most utilities now require on every sanitary manhole, is run in minutes before backfill with the pipes plugged, and tests every section joint, connector, and lining at once; an exfiltration test fills the manhole to the frame and measures the drop, which takes a day and a water source and is the test of a manhole that cannot be sealed for vacuum; a visual inspection catches running infiltration and nothing else, and is the acceptance of owners who test the pipe and accept the structure on the precaster's certification; no test is the position of a private system whose owner will not meter its infiltration. (15.2.2)
15.2.3 The vacuum test shall be performed after the manhole is complete and before exterior backfill is placed, in accordance with ASTM C1244, and where a chimney seal is furnished the test shall be repeated or performed after the frame is set so that the chimney is included.
15.2.4 The manhole shall be evacuated to 10 in. of mercury, the pump valved off, and the time for the vacuum to fall to 9 in. of mercury measured against the minimum time tabulated in ASTM C1244 for the manhole diameter and depth.
NOTE ASTM C1244 is a before-backfill test, and running it after backfill inverts what it proves: the surrounding soil holds the joints closed under the applied vacuum, so a manhole that would leak under service conditions can pass. (15.2.5)
15.2.6 A manhole that fails shall have the leak path located, sealed by re-seating the joint, replacing the connector, or applying an external sealing band per ASTM C877, and shall be retested until it passes.
15.2.7 Where a manhole is retested more than twice, the Engineer of Record may require the manhole to be removed and rebuilt, and the Contractor shall bear that cost where the failure results from the Contractor's work.

15.3 Deflection Testing

15.3.1 The maximum allowable installed deflection of flexible pipe shall be as indicated in the datasheet.
Allowable Installed Pipe Deflectionrange
Not more than
%
357.5
15.3.2 Every reach of PVC and polyethylene gravity sewer, mains and laterals, shall be deflection tested by mandrel pull-through after final backfill is in place and the trench has stood undisturbed not less than 30 days, or after the final cover load including pavement is in place, whichever occurs later.
NOTE The 30-day wait lets the soil envelope reach its post-construction state, and a mandrel pulled the week after backfill can pass a reach that will fail the same test a season later. (15.3.3)
15.3.4 The mandrel shall be a rigid, non-adjustable, odd-numbered-leg go or no-go device sized to the pipe base inside diameter less the allowable deflection, and the base inside diameter shall be the value the product standard tabulates for the pipe furnished.
15.3.5 The mandrel shall be pulled by hand or with light mechanical assistance, and shall not be pulled with a winch or any force capable of deforming the pipe.
15.3.6 The Contractor shall not modify a mandrel, substitute a smaller mandrel, or ream the pipe to pass a reach.
15.3.7 A reach that fails the deflection test shall be uncovered and re-bedded, or replaced, at the Contractor's expense, and shall be retested after a further 30 days.
NOTE Excessive deflection almost always traces to the haunch: embedment that was dumped rather than worked under the pipe, a lift thickness that could not be compacted, or heavy equipment crossing before the cover was there to spread it. (15.3.8)

15.4 Force Main Hydrostatic Testing

15.4.1 The force main shall be hydrostatically tested from the station discharge connection to the receiving manhole at the test pressure indicated in the datasheet, in accordance with AWWA C600 for ductile iron, AWWA C605 for PVC, and ASTM F2164 for polyethylene.
Force Main Hydrostatic Test Pressurerange
psi
5075100125150175200250300
Derived — the force main design working pressure at the lowest point of the test section (by default)
15.4.2 The test pressure shall be not less than 1.5 times the design working pressure measured at the lowest point of the test section, and not less than 100 psi, unless the utility owner's standard requires a different pressure.
NOTE The test pressure is a multiple of the working pressure rather than a fixed number because the working pressure of a force main is set by the static lift and the friction of the particular profile, and a test at a fixed pressure either fails to prove a high-head main or overstresses a low-head one; the floor keeps a short low-head main from being tested at a pressure a leaking joint would pass. (15.4.3)
15.4.4 The allowable makeup water during the test shall be the allowance the installation standard for the pipe material computes for the test pressure, pipe size, and length, and a polyethylene main shall be tested by the pressure-decay procedure of ASTM F2164 with no makeup after the expansion phase.
15.4.5 The test shall be held for not less than two hours after the test pressure is reached and the pipe has been purged of air through the air valves, and the pressure shall not vary by more than 5 psi during the test.
NOTE A force main with an air pocket in it passes a pressure test and fails in service, because the air compresses to absorb the makeup water that a leak would otherwise show; purging through the air valves before the test starts is what makes the makeup allowance mean anything. (15.4.6)
15.4.7 A test section that fails shall have the leak located, repaired, and retested until it passes, and the Contractor shall bear the cost of the repair and of every retest.
15.4.8 The lift station discharge valves shall be closed and the station isolated from the test section during the test, and the test pressure shall not be applied to the station piping, which is tested under Packaged Pump StationsPackaged Pump and Lift StationsResolves to the current adopted revision.sync/packaged-pump-stations.

15.5 Video Inspection

15.5.1 The extent of post-installation video inspection shall be as indicated in the datasheet.
Post-Installation Video Inspection Extentselect
All sanitary sewer mains and laterals
All sanitary sewer mains
Reaches selected by the Engineer of Record
No video inspection
NOTE Video is the only acceptance method that finds a sag that holds sewage, an intruding gasket, a lateral tap protruding into the barrel, a joint offset, and a bellied lateral, and it is the record the Owner uses as the baseline for every future inspection; televising every main is the position most utilities now take at dedication, adding the laterals is the position of owners who have paid to replace a lateral the camera would have caught, and sampling or omitting it is the position of a private owner on a short system whose other tests passed. (15.5.2)
15.5.3 Video inspection shall be performed after final cleaning and after the deflection test, with the pipe free of standing water except where the camera is submerged-rated and the water depth is recorded.
15.5.4 The video record shall be continuously referenced to distance from the starting manhole and shall identify each manhole, joint, service connection, and defect observed, and the camera shall be stopped and rotated at each lateral connection.
15.5.5 Standing water in the video record at any point in a reach that was laid on a positive slope shall be treated as a sag and the reach shall be surveyed to establish the depth and length of the sag.
15.5.6 Defects identified in the video record, including any sag deeper than the pipe manufacturer's installation tolerance, shall be corrected and the affected reach re-inspected, at the Contractor's expense where the defect results from the Contractor's work.

15.6 Test Records

15.6.1 Every test, whether passing or failing, shall be recorded on a report identifying the reach or structure, the pipe material and size, the test method, the test pressure or head, the hold time, the start and end readings, the date, and the names of the Contractor's test supervisor and the witnessing inspector.
15.6.2 Test reports shall be submitted within five working days of the test.
15.6.3 The Contractor shall not remove or replace a failing test report with the report of a subsequent passing test.

15.7 Final Acceptance

15.7.1 Final acceptance of the sanitary sewer system shall require passing results on every required test for every reach, lateral, structure, and force main section, video records where video inspection is required, complete record drawings including the lateral record, removal of all plugs and temporary flow controls, final cleaning, and the acceptance of the Authority Having Jurisdiction and the utility owner for any portion connected to or to be dedicated to public infrastructure.
15.7.2 Acceptance shall not waive the Contractor's warranty obligations or the Contractor's liability for latent defects.
NOTE Sanitary sewer defects are frequently invisible at acceptance and appear with the first wet season that raises the groundwater over the joints, or with the first tenant whose lateral was never televised, which may be months after the Owner has taken the site. (15.7.3)

16 Cleaning and Turnover

16.1 The completed system shall be cleaned of sediment, debris, mortar droppings, and construction materials after all testing is complete and before turnover.
16.2 The final cleaning method shall be as indicated in the datasheet.
Final System Cleaning Methodselect
Hydraulic jet flushing with vacuum recovery of debris
Mechanical bucket cleaning
Manual removal from structures
NOTE Jet flushing with a vacuum truck downstream cleans every reach and recovers what it moves, and it is the method every utility runs on its own system; bucket cleaning is used on a large-diameter reach that a jet cannot scour; manual removal from the structures is sufficient only on a short system with no debris in the pipe, which the video record is what proves. (16.3)
16.4 Debris and sediment removed during cleaning shall be captured at the downstream end of the reach being cleaned and shall not be flushed into the downstream system, into the public sewer, or into a lift station.
16.5 Sediment removed during cleaning shall be disposed of off site or at a location approved by the Owner in writing.
16.6 Manhole benches, channels, and inverts shall be flushed and left free of standing sediment, and air valve vaults shall be cleaned and their drains verified open.
16.7 Covers shall be cleaned of construction debris and shall be verified to seat in their frames without rocking.
16.8 Every plug, bypass connection, and temporary flow control within the system shall be removed at turnover, and the Contractor shall certify in writing that none remains.
NOTE A test plug left in a lateral stub or a bypass hose left in a manhole is found when the first building connects and backs up, and the search for it is an excavation. (16.9)
16.10 The Contractor shall conduct a final walk-through with the Engineer of Record, opening each manhole and air valve vault to verify clean condition, and shall correct any deficiency found before final acceptance.

17 Delivery, Storage, and Handling

17.1 Pipe, fittings, structures, castings, and valves shall be handled with slings, forks, or lifting hardware appropriate to the product, and shall not be dropped, rolled off a truck bed, or dragged.
17.2 Pipe shall be stored on level ground, blocked against rolling, and stacked no higher than the pipe manufacturer's published stacking limit.
17.3 Gaskets, lubricant, and resilient connectors shall be stored in their original containers, out of direct sunlight, away from petroleum products and ozone-generating equipment, and within the temperature range published by the gasket manufacturer.
NOTE Ozone and ultraviolet exposure attack elastomeric compounds directly, and a gasket that spent a season on an open pallet can fail in service without ever showing damage at the moment it was installed. (17.4)
17.5 Thermoplastic pipe stored on site longer than the exposure period published by the pipe manufacturer shall be covered with an opaque covering that permits air circulation.
17.6 Lined ductile iron pipe and lined precast sections shall be stored and handled so that the lining is not scored, and lining damage shall be repaired with the lining manufacturer's repair procedure or the item rejected.
17.7 Pipe, fittings, and structures shall be inspected for damage on delivery and again immediately before installation, and damaged material shall be removed from the site rather than repaired in place unless the manufacturer publishes a repair procedure and the Engineer of Record accepts it.
17.8 Pipe interiors shall be kept free of debris during storage and installation, and open pipe ends shall be closed at the end of each work day.
NOTE An open pipe end left overnight is how construction debris, animals, and washed-in sediment enter a reach that will later be tested and accepted with them still inside. (17.9)

18 Warranty

18.1 The warranty period for the sanitary sewer system shall be as indicated in the datasheet.
Sanitary Sewer System Warranty Periodrange
Not less than
years
1235
18.2 The Contractor shall warrant the sanitary sewer system, including pipe, joints, laterals, cleanouts, manholes, castings, chimney seals, embedment, the force main and its appurtenances, and connections, against defects in materials and workmanship for the warranty period beginning at substantial completion.
18.3 Warranty obligations shall include correction of leaking joints and connectors, infiltration at any structure, pipe deflection developing after acceptance, a sag found by the Owner's video within the warranty period that was not shown on the acceptance video, settlement of pavement over sewer trenches, structure rim settlement, and castings that rock or move in their frames.
18.4 Where the Contractor repairs or replaces work under the warranty, the repaired work shall carry a warranty running from the date of the repair for the full warranty period or for the remainder of the original period, whichever ends later.
18.5 The Contractor shall bear the cost of the warranty repair itself, of bypass pumping and flow control during the repair, and of restoring the pavement, curb, landscape, and surface finishes disturbed by that repair to the condition documented in the preconstruction condition record for that area.
18.6 The Contractor's warranty shall cover pavement settlement over a sewer trench where the settlement is attributable to consolidation of the trench backfill, and shall not cover settlement attributable to subgrade conditions outside the trench.
18.7 Where the parties disagree whether settlement is attributable to trench backfill, or whether infiltration found within the warranty period results from a defect in the work, the Engineer of Record shall make the initial determination.
NOTE Trench backfill consolidates through the first seasonal cycles even when it was placed correctly, so pavement that was flush at paving often shows a visible depression along the trench line a year later, and the question in every case is whether the depression reflects consolidation of properly placed backfill or a lift that was never compacted. (18.8)
18.9 Manufacturer warranties for castings, precast structures, air valves, and isolation valves shall be assigned to the Owner at closeout.
18.10 The warranty period shall not limit the Contractor's liability for non-conforming work discovered after it expires.
NOTE Pipe laid at an incorrect slope, a lateral connected with a hand-cut saddle, a structure joint that was never sealed, a casting under-rated for its location, and a pipe material substituted from the one specified are non-conforming work whenever they are discovered, not defects that expire with the warranty. (18.11)

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"Sanitary Sewer Systems (Site)," SynC Standards, revision 5. Licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://synergyinconstruction.com/standards/general/sanitary-sewer-systems. Reference material only; not professional engineering advice and provided without warranty. Verify against governing codes and have a licensed professional review before use.