Township of Northville, MI Design and Construction Standards for Sanitary Sewer Systems

In streets. Sanitary sewers shall generally be located on opposite sides of streets from water mains, on the south side or the west side of a street.

In easements. Easements for sanitary sewers shall have a minimum width of 20 feet centered upon the sewer. Such easements shall be granted to the Township with restrictions against use or occupation of building structures and by other utilities in any manner which would restrict sewer maintenance or repair operations.

Easements for possible extensions of the sanitary sewer shall be provided to the property lines or subdivision boundary line, at locations designated by the Wayne County Department of Public Services and/or by the Director.

Sewers shall preferably be constructed outside of paved parking areas, streets and drives.

Sewer capacity.

Tributary area. Sanitary sewers shall be designed to serve all naturally tributary areas at full development. Topography, the master sanitary sewer plan, current zoning, and the Township's master land use plans shall be considered when determining the required capacity.

Populations. For design purposes, population shall be based on a minimum of 3.2 persons per detached single-family home and 2.5 persons for each multiple-family dwelling unit. Submissions for review shall include a tabulation of occupancy (usage) types and the conversion of these into terms of equivalent single-family units. The unit factors as established by the Township shall be used to convert the different usage types to equivalent single-family units.

Sewage quantities for pipe design.

For service areas with design populations of 500 or less, sewer design capacity shall be 400 gallons per capita per day, as specified under the Ten State Standards of GLUMRB.

For service areas with design populations greater than 500 but less than 28,400, sewer design capacity shall be based on the following formula:

	Where:
	Q	=	Design capacity in gallons per capita per day.
	P	=	Design population expressed in thousands.

For service areas with design populations exceeding 28,400, sewer design capacity shall be 250 gallons per capita per day.

Minimum pipe size. Minimum pipe size for sanitary sewers shall be eight inches diameter.

Hydraulics.

Calculations. Kutter's or Manning's formula, with n = 0.013 for concrete or n = 0.009 for PVC, shall be used.

Minimum and maximum velocities. Minimum design velocity shall be two feet per second. The maximum design velocity shall be 10 feet per second with pipe flowing full. The minimum slope of the sewer between the last two manholes at the upper end of any lateral shall be 1.0%. Whenever additional slopes are available, minimum grades of 1% shall be utilized on lateral sewer lines.

Allowable pipe slopes.

Pipe Diameter (inches)	Minimum Slope (feet per 100 feet)	Maximum Slope (feet per 100 feet)
6	1.000	10.00
8	0.400	10.00
10	0.280	7.00
12	0.220	5.30
15	0.150	3.90
18	0.120	2.90
21	0.100	2.32
24	0.080	1.92
27	0.067	1.64
30	0.058	1.44
36	0.046	1.12

Allowances for changes in pipe direction. Maximum flow velocity for full pipe flow shall be maintained by a 0.10-foot difference in invert elevations between the inlet and outlet pipes whenever the direction change exceeds 30°.

Allowance for pipe size changes. At manholes where a change in the pipe size occurs, the grades for the pipe shall be established by matching 0.8 of the diameters of each pipe above inverts.

(6)

Depth of sewers.

Minimum depth. Unless specifically otherwise approved by the Director, no sanitary sewer shall have less than four feet of cover over the top of the pipe. In general, sanitary sewers shall have a minimum of 10 feet of cover below finished road surface grade. The minimum depth of force mains shall be six feet (to top of pipe).

Depth below building grade. Unless otherwise approved by the Director, the top of any sanitary sewer shall be at least 10 feet below finished building grade elevation of each fronting property which the sewer is designed to serve.

Pipe material for sewer shall be polyvinyl chloride (PVC), reinforced concrete or ductile iron as specified below.

PVC pipe.

PVC pipe eight inches through 15 inches in diameter shall meet or exceed all of the requirements of the current ASTM D-3034 for heavy wall SDR-26 polyvinyl chloride sewer pipe and fittings. PVC pipe of 18 inches in diameter shall meet or exceed all requirements of the current ASTM F-679 for heavy wall SDR-26 polyvinyl chloride sewer pipe and fittings.

PVC pipe shall be jointed with ring gasketed bell ends. Jointing materials shall be applied to the bell end of the pipe at the point of manufacture in such a manner that a tight uniform joint will be achieved and such that when the joint is made up in the field, the joint material will not roll or tear from the pipe. A proper joint lubricant shall be furnished by the pipe manufacturer.

PVC corrugated pipe with a smooth interior eight inches through 10 inches shall meet or exceed all of the requirements of the current ASTM F-949 for heavy wall A-2026 polyvinyl chloride sewer pipe and fittings.

Reinforced concrete sewer pipe.

Reinforced concrete sewer pipe shall conform to the requirements of ASTM C76, Class IV.

Joints shall conform to the requirements of ASTM C443, "Joints for Circular Concrete Sewer and Culvert Pipe, Using Rubber Gaskets," with the exception that gasket material shall be synthetic rubber only. Joints in concrete pipe having a diameter of 30 inches or larger shall be pointed on the inside with mortar, after backfilling has been completed. A proper lubricant shall be supplied by the manufacturer.

Concrete pipe can be used for sewer 15 inches in diameter and greater.

Ductile-iron pipe.

Ductile-iron pipe shall be Pressure Class 250 with double cement lining and shall meet current requirements of ANSI A21.50, with cement lining. Ductile iron pipe and fittings shall also be poly-wrap encased per the requirements noted in Article VII (water system) of this chapter.

The Township requires an interior pipe coating when ductile-iron pipe is used (Protecto 401 or approved equal) as recommended by the manufacturer to defer potentially corrosive action from the sewage. Because the depth of the sewer will be significant when ductile-iron pipe is used, this requirement is mandatory.

Mechanical type joints, when specified, shall conform to the current ANSI A21.11, "Rubber Gasket Joints and Cast Iron Pressure Pipe and Pipe and Fittings." Bolts and nuts shall be Cor-Blue T-Bolts with a ceramic-filled, baked-on fluorocarbon resin.

Push-on type joints, when specified, shall conform to the current ANSI A21.11 and shall be "Tyton," "Super Bell-Tite," or approved equal.

Force mains (sanitary sewer pressure pipe). All open cut force mains shall conform to the ductile-iron pipe requirements for gravity sewers. Pressure testing of force mains shall follow the pressure test requirements for water mains of similar material. Tracer wire shall be installed along all force mains. Tracer wire shall meet the material requirements of tracer wire for water main and be green in color.

Directional drill materials for force mains and gravity sewers.

HDPE (for directional drill applications only).

Sanitary sewer pipe and fittings shall be high-density polyethylene plastic pipe, DR11, IPS, manufactured in accordance with the specifications and requirements of AWWA C906.

Materials used for the manufacturing of polyethylene pipe and fittings shall be extra-high molecular weight, high-density PE 4710 polyethylene resin meeting the ASTM D3350 minimum cell classification of PE 345464C. The cell classification properties of the material shall be certified by the supplier.

Polyethylene material shall have a minimum hydrostatic design basis (HDB) of 1,600 psi at 73.4° F. when tested in accordance with ASTM D2837.

HDPE fittings shall be in accordance with ASTM D3261 (butt fused) and shall be manufactured by injection molding, a combination of extrusion and machining, or fabrication from HDPE pipe conforming to this specification and by the manufacturer of the pipe. The fittings shall be fully pressure rated and provide a working pressure equal to that of the pipe with an included 2:1 safety factor. The fittings shall be manufactured from the same base resin type and cell classification as the pipe itself. The fittings shall be homogeneous throughout and free from cracks, holes, foreign inclusions, voids, or other injurious defects.

The HDPE pipe shall contain no recycled compound except that generated in the manufacturer's own plant. The physical appearance of the pipe having deformities such as concentrated ridges, discoloration, excessive spot roughness, pitting, varying wall thickness, etc., shall constitute sufficient basis for rejection. The HDPE pipe shall be homogenous throughout, free from visible cracks, foreign inclusions and other defects that may affect the wall integrity.

A certificate of "compliance with specification" shall be furnished for all materials to be supplied.

PVC, C900 or C905.

Fusible PVC plastic material for pipe shall conform to AWWA C900 or C905, DR-18 (C900) OR DR25 (C905), IPS, ASTM D2241. Compound formulation shall be in accordance with PPI TR-2/2006.

Pipe shall be manufactured with 100% virgin resin. Pipe shall also have 0% recycled plastics content and shall not consist of any rework compound, even that obtained from the manufacturer's own production using the same formulation.

Fusible PVC pipe shall be extruded with plain ends. The ends shall be square to the pipe and free of any bevel or chamfer. There shall be no bell or gasket of any kind incorporated into the pipe.

Fusible PVC pipe shall be manufactured in forty-foot nominal lengths.

Fusible PVC pipe shall be green in color.

Pipe shall be marked per AWWA C900 or AWWA C905 as specified on the plans and shall include, as a minimum:

[a]

Nominal size.

[b]

PVC.

[c]

Dimension Ratio, Standard Dimension Ratio or Schedule - DR-18 (C900) OR DR-25 (C905), IPS.

[d]

AWWA pressure class or rating - Pressure Class 150.

[e]

AWWA standard designation number.

[f]

Extrusion production-record code.

[g]

Trademark or trade name.

[h]

Cell Classification 12454 and/or PVC material code 1120 may also be included.

(6)

Pipe markings. All sanitary sewer pipe shall have the class and date of manufacture marked on each length by the manufacturer. In addition, the lot number shall similarly be marked on all reinforced concrete pipe.

(7)

Pipe fittings.

Fittings shall be of the same material as the pipe, and in no case shall the walls be thinner than that of the pipe furnished.

Wye and tee fittings for PVC pipe shall be reviewed by the Director before purchasing.

The dry fit of all fittings must be snug. If the fit is such that it is loose, the pipe or fittings will be rejected as faulty and of improper size.

Building leads.

Inclusion with sewer construction. Unless otherwise approved by the Director, construction of building leads from the public sewer to a point five feet inside the property line or five feet outside the sewer easement for each fronting parcel which the sewer is designed to serve shall be included with the construction of each sanitary sewer.

Where the construction of building leads to the property line is not required, a wye branch with riser is required. Said wye and riser shall be provided with a watertight stopper or plug with type of joint used for the sewer pipe and shall be installed for every lot or building site which the sewer is designed to serve. Solvent weld caps are not permitted for ABS and PVC service leads.

Size and length. Minimum size for building sewer and building lead shall be six inches nominal internal diameter. Generally the maximum length of building sewer and building lead shall be 100 feet as measured from the main sewer to the building. Cleanouts shall be installed at maximum intervals of 75 feet.

Minimum slope. Minimum slope for building leads shall be 1/8 inch per foot (1.00%).

Allowable types of pipe and pipe joints.

Six inches nominal diameter pipe. Polyvinyl chloride (PVC) solid wall pipe shall conform to the requirements of ASTM for such pipe and shall be not less than Heavy Wall SDR 23.5.

Larger size pipe. Larger size building leads shall be constructed of materials permitted in these standards for sanitary sewers.

Joints for wyes, tees and stoppers. Joint for wyes and stoppers shall be of the same type as the joint used for the sanitary sewer pipe, except as otherwise noted.

Manholes.

Manhole locations. Manholes shall be constructed at every change in sewer grade, alignment and pipe size and at the end of each sewer line. Maximum distance between manholes shall be 400 feet.

Drop manholes. Whenever an inlet sewer pipe enters a manhole at an invert elevation 24 inches or more above the invert elevation of the outlet sewer pipe, a drop manhole shall be constructed. Drops between six inches and 24 inches will not be permitted.

Stubs. Stubs or blind drop connections with watertight plugs shall be provided where future connections to a manhole are anticipated.

Materials. Manholes shall be constructed of precast reinforced concrete sections conforming to ASTM C478. Joints between precast sections shall be modified tongue-and-groove type using O-ring synthetic rubber gaskets.

All manholes shall contain a bottom precast section of flexible joints and shall consist of a base integrally cast with a riser section. The base shall be a minimum of eight inches thick and contain reinforcement in the riser section.

Manholes with precast flow channels are not permitted. Concrete channels must be poured from the upstream invert(s) to the downstream invert with a smooth, consistent grade.

The joint between the pipe and a section of a precast flexible joint manhole shall be a mechanically compressed joint, such as the Res-Seal, Link-Seal, Press Wedge II, or Kor-N-Seal, Press Wedge II, or Kor-N-Seal flexible rubber manhole joint. The joint shall be capable of meeting infiltration requirements and shall permit a deflection of at least six degrees in all directions as measured from the center line of the pipe. Resilient connections between manhole and pipe shall conform to ASTM C443 and ASTM C923, except that only synthetic rubber gaskets shall be permitted. Natural rubber will not be acceptable.

Manholes and grade rings shall conform to the current ASTM specifications for precast reinforced concrete manhole sections, serial designation C478. Manhole section joints shall be of the O-ring type. Dome sections shall be straight side type.

(e)

Cone section shall be eccentrically constructed precast reinforced concrete.

(f)

Mortar for plastering manholes shall be made of one part portland cement and two parts fine aggregate.

(g)

A galvanized capped test pipe of 1/2 inch in diameter shall be installed through the manhole wall and extend two inches into the manhole at an elevation equal to the top of the lowest sewer pipe.

(h)

Manhole frames and covers shall weigh not less than 350 pounds. Each frame and cover shall have machined bearing surfaces and shall have machined bearing surfaces and shall be suitably notched for convenient removal of the cover. Each cover shall be marked "NORTHVILLE TOWNSHIP SANITARY SEWER" in raised letters spaced in from the periphery of the cover.

(i)

All manhole frames and covers shall be coated by the manufacturer with coal tar pitch varnish or other asphaltum coating reviewed by the Director.

(j)

Covers and frames shall be watertight boltdown rubber gasket type manhole cover, equal to East Jordan 1040-PT.

(k)

Manhole steps shall be reinforced polypropylene plastic coated. They shall be M.A. Industries, Inc. PS-I-PF.

Manhole connections.

Sewer pipe to manhole connections shall be through:

A flexible rubber boot which shall be securely clamped into a core-drilled pipe port. Pipe ports shall be securely clamped into a core drilled at the point of manhole manufacturer and shall be accurately located within 1/2 inch of proposed sewer center line; or

A self-adjusting mechanical pipe to manhole seal which provides a resilient flexible and infiltration-proof joint (Res-Seal); or

A flexible rubber wedge firmly rammed into a rubber gasket which is cast into the manhole (Press Wedge II) or equal.

Neoprene rubber for the manhole boot shall meet ASTM Specifications C443 and shall have a minimum thickness of 3/8 inch. Pipe clamp bands shall be of corrosion-resistant steel.

The void between the flexible boot to the sewer pipe shall be filled with Greatstuff Pro expandable foam as manufactured by Dow Chemical, or approved equal.

Special structures and appurtenances.

General requirements. Where special appurtenances or structures are required in the sanitary sewer system, preliminary plans shall be submitted for review and comment.

Inverted siphons. Inverted siphon design shall provide at least two independent parallel pipes, with minimum diameter of six inches each, sized to provide a minimum velocity of three feet per second for the average flow condition.

Pumping stations. Sewage pumping stations shall be wet well mounted, duplex as manufactured by Smith & Loveless, Inc. or approved equal. Pumping station design shall conform to the requirements of the Director or his designee.

§ 72-34 Plan requirements.

All construction plans shall be submitted to the Township for sanitary sewer approval and shall contain, but not be limited to, the following information:

Certification. The plans and specification shall be prepared under the supervision of a civil engineer registered in the State of Michigan. The title sheet of the plans shall contain the signature and seal of that engineer.

Plan contents. Plans shall consist of a title sheet showing a plan view of the complete job, split plan and profile sheets, and standard detail sheets. Sheet sizes shall be 24 inches by 36 inches.

Title sheet. A title sheet, or the first sheet of a set of plans, shall identify:

Project title.

Location map with North arrow and scale, drawn at a scale not greater than one inch equals 100 feet nor smaller than one inch equals 2,000 feet. Locations of proposed sewers and relationship of general project area to the surrounding area shall be shown.

Overall layout of the sewer system with manhole numbers.

Sheet index.

Symbol legend.

List of quantities.

Name, address, phone number and e-mail of proprietor.

(h)

Name, address, phone number and e-mail of designer.

(i)

Plan completion date and all revision dates.

(j)

A statement that the work shall conform to the Township's current standards and specifications.

(k)

Provide calculations to identify the average day and peak hour sewage flow.

Plan and profile sheets.

Scale of plan portion of sheet shall be one inch equals 50 feet, or larger, with scale of profile portion of sheet one foot equals five feet vertical or proportionally larger.

Plan portion of sheet shall include, at least:

Two bench marks shall be shown on each plan sheet. Plans shall be prepared based on the Michigan South State Plane Coordinates, North American Datum of 1983 (NAD 1983) for the x and y coordinate system, and based on the North American Vertical Datum of 1988 (NAVD88) for the z coordinate system.

Existing topography extending 50 feet past the site boundaries, including all existing and proposed improvements. Elevation contours shall be at a minimum of two-foot intervals.

Street names, street and easement width, subdivision names, lot numbers and lot dimensions.

Location, length, size of each section of proposed sewer between manholes.

Locations of all manholes and other sewer appurtenances and special structures.

All proposed building leads and wyes. Length, size, end of lead invert elevations, and length of riser shall be shown.

[7]

Dimensions to manholes and sewers from property lines, right-of-way lines or buildings.

[8]

"Miss Dig" note.

[9]

Limits of special backfill requirements.

Profile portion of sheet shall appear below the corresponding plan portion, generally projected vertically, and shall show, at least, the following:

Size, slope, length, type and class of pipe.

Invert of each pipe and top-of-casting elevations at each manhole.

Limits of special backfill requirements.

Profiled elevations over center line of proposed sewer of existing and proposed ground, and pavement surfaces. The existing profile shall be obtained from actual field survey data.

All crossings with other utilities (existing or proposed) with elevations of the top or bottom of the pipe, as appropriate, and shall have "Warning" notes for all gas main crossings in profile.

Location, by station, or coordinate, of every proposed manhole with manhole number, top-of-casting elevation, and manhole type.

[7]

Location by station, or coordinate, of all building sewers, and wye branches.

Detail sheets. Provide Township standard detail sheets consisting of specifications and drawings. Wayne County details shall also be provided, where applicable.

§ 72-35 Construction standards.

All sanitary sewers proposed within the Township shall be constructed in accordance with the standards and specifications contained herein or, when by reference, the code.

Wyes, riser and building leads.

All wye branches in the sewer pipe shall have manufactured joints. All pipes containing wye branches shall be installed with the main sewer. Wyes for vacant property shall be installed opposite the center of the frontage unless otherwise indicated. The final location of the wye shall be determined by the Director or his designee at the time of construction. All wyes that are installed with building leads shall end with an approved stopper.

The ends of leads shall terminate with an approved stopper set five feet inside the property line or five feet outside the easement line. The ends shall be marked with a hardwood stake two inches by two inches placed vertically from the pipe invert to the ground service.

Connections.

A channel shall be constructed within the existing manhole or other structure, at which the connection is to be made to direct the flow to the existing outlet. Any portion of the existing structure which would interfere with such construction shall be removed.

When connections are made with sewers in service, no part of the work shall be built under water. A flume or dam must be installed and pumping maintained until completed. All the new work shall be kept dry until completed. All the new work shall be kept dry until completed and until all concrete or mortar has sufficiently cured.

The contractor shall install a watertight bulkhead to prevent water, sand, silt, etc., from entering the existing sewer system. The bulkhead shall be left in place until the sewer has been tested and approved by the Director and other entities having jurisdiction.

Wherever existing manhole structures are to be tapped, holes shall be drilled at four inches center to center around the periphery of any proposed pipe opening to create a plane of weakness before breaking out the section. The pipe (stub or saddle) to be placed between the pipe and the inside wall of the manhole filled cement mortar and trawled smooth. Voids outside the pipe barrel shall be sealed with an approved nonshrinking grout. A concrete collar shall then be poured 12 inches thick around the pipe, and extended a minimum 12 inches beyond the outside wall of the manhole. The concrete collar shall bear on undisturbed earth of fully compacted backfill.

Whenever a pipe is to be tapped, a saddle-type wye connection shall be used. The opening in the existing pipe wall shall be cut with a masonry circular saw. A concrete collar four inches thick shall then be poured around the existing pipe extending 12 inches on either side of the connection.

Manholes. Construction methods shall conform to the requirements of these specifications and Section 5.14.03 of MDOT 1984 Standard Specifications for Construction with the following stipulations and exceptions:

Pipe shall not extend into a manhole beyond the inside face of the manhole wall.

Concrete placed inside precast flexible joint manholes to form the channel through the manhole shall not be placed between the pipe and the opening in the manhole base section so as to interfere in any way with the flexibility of the joint.

A minimum of three inches and a maximum of 15 inches of adjustment rings with gaskets shall be placed on the cone section of all manholes.

Manhole assembly shall be in accordance with the manufacturer's recommendation. The bell and spigot surfaces shall be wiped clean. The surfaces shall be wiped clean. The surfaces (bell, spigot, synthetic rubber O-ring gasket) shall then be coated with a lubricating material.

All lift holes and joints within precast manholes shall be plugged and mortared.

(6)

All manholes shall be supported on a firm stable foundation.

(7)

Channels shall be constructed by a single concrete pour. Concrete shall be MDOT 30M or 30P. No brick or block will be allowed as filler.

Casting adjustments.

Adjustments to manhole castings shall be accomplished prior to final acceptance by using precast concrete adjustment rings bolted to the connection of the manhole with synthetic rubber O-ring gaskets compressed between each adjacent ring.

Manhole castings located within pavement areas shall be adjusted a maximum of 15 inches using four cadmium-coated five-eighths-inch-diameter threaded studs with adjustment support nuts for setting frame to correct grade as detailed on the plan. The void between casting and top of cone section shall be completely filled with stiff MDOT 30m or 30P concrete mix having less than three inches slump. A Cadilloc brand rubber wrap for watertightness shall be applied to the exterior of the adjustment after the concrete has taken its initial set, and is resistant to damage, unless otherwise specified by the Director.

Acceptance tests. All tests shall be conducted under the supervision of the Director. No acceptance tests, excluding compaction testing, shall be conducted until the entire sewer system is constructed and has been installed for not less than 30 days. All PVC lines shall be tested for deflection. Sewer pipe 24 inches and smaller shall be air tested. Sewer pipe larger than 24 inches shall be tested by either infiltration or exfiltration and shall be tested in lengths of 1,600 feet or less. A copy of all test results shall be furnished to the Director.

Compaction test.

Where sanitary sewer is constructed in pavement areas, or where the sewer is within a one-on-one influence of pavement, compaction testing shall be performed by an independent testing laboratory.

Testing shall be performed at intervals of one test per layer per 75 feet of trench or as determined necessary by the Director.

Test for leakage; air test.

After a manhole-to-manhole section of line has been backfilled and cleaned, it shall be plugged at each manhole with pneumatic plugs. The design of the pneumatic plugs shall be such that they will hold against the line test pressure without requiring external blocking or bracing.

There shall be three hose connections to the pneumatic plug. The second hose shall be used for continuously reading the air pressure rise in the sealed line. The third hose shall be used only for introducing low-pressure air into the sealed line.

There shall be a 0-30 psig gauge for reading the internal pressure of the line being tested. Calibrations from the 1-10 psig range shall be in tenths of pounds (not ounces), and this 0-10 portion shall cover 90% of the complete dial range.

Low-pressure air shall be introduced into the sealed line until the internal air pressure reaches 4.0 psig greater than the average back pressure of any groundwater pressure that may be over the pipe. At least the stabilization period the third hose shall be disconnected.

(e)

The portion of line being tested shall be accepted if the portion under test meets the following conditions:

DI and RCP pipes.

[a]

The time requirement for the pressure to decrease from 3.5 psig to 2.5 psig (greater than the average back pressure of any groundwater that may be over the pipe) shall not be less than the time given in the following table:

	Pipe Size (inches)	Minutes Holding Time (seconds/100 feet of pipe)
	4	18
	6	42
	8	72
	10	90
	12	108
	15	126
	18	144
	21	180
	24	216

[b]

Immediately prior to the performance of the line acceptance test, the groundwater level shall be determined by removing the pipe cap, blowing air through the pipe nipple into the ground so as to clear it, and then connecting a clear plastic tube to the pipe nipple. The hose shall be held vertically and a measurement of the height in feet of water shall be taken after the water stops rising in this plastic tube. The height in feet shall be divided by 2.3 to establish the pounds of pressure that will be added to all readings. For example, if the height of water is 11 1/2 feet, then the added pressure will be five psig. This makes the 3.5 psig to be 8.5 psig and the 2.5 psig to be 7.5 psig. The one-pound allowable drop and the timing remains the same.

PVC pipe.

[a]

The time requirement for the pressure to decrease from 3.5 psig to 3.0 psig (greater than the average back pressure of any groundwater that may be over the pipe) shall be calculated as shown in the following table, where "L" equals the length of sewer to be tested in feet; however, in no instance shall the holding time be less than the minimum values shown in the following table:

Pipe Size (inches)	Holding Time (seconds)	Minimum Holding (seconds)
4	0.190XL	113
6	0.427XL	170
8	0.760XL	227
10	1.187XL	283
12	1.709XL	340
15	2.671XL	425
18	3.846XL	512

[b]

If any section of the sewer fails to meet this requirement, the contractor shall perform a television inspection of the faulty section and repair or replace all defective materials and/or workmanship to the satisfaction of Director. The test procedure shall be repeated until the results are acceptable.

Television inspection.

All sanitary sewers shall be television inspected with test results approved by the Director prior to placing the sewer into service.

All courses not true to line or grade shall be dug up, relayed and re-televised. Television inspection for all sanitary sewers eight inches in diameter and above shall be provided by the contractor.

Deflection testing for PVC pipe.

All completed installation shall at no point have out-of-round pipe deflections greater than 5%. The Director shall have the option of requiring deflectometer or go-no gauging tests run prior to acceptance on pipe lines where high deflections are suspected. Pipe with deflections greater than 5% will be considered unacceptable and shall be relayed by the contractor.

Deflection of PVC pipe shall be tested by pulling a wooden pig or equivalent through the pipe. The pig shall be constructed in accordance with the following table of maximum outside diameters and shall be submitted to the Director for review before testing in initiated.

	Pipe I.D. (inches)	Pig O.D. (inches)
	6	5.45
	8	7.28
	10	9.08
	12	10.78
	15	13.20
	18	16.12

The pig shall be drawn through the pipe from manhole to manhole. Any portion of pipe through which the pig passes freely shall be deemed to have passed the deflection test. Sections of pipe through which the pig does not pass shall be located, uncovered and the pipe zone bedding improved and backfilled by the contractor. The pipe shall be retested before acceptance is granted.

In the event the line does not pass the infiltration test as stated above, the test shall be repeated after suitable repairs have been completed.

Documents required prior to final acceptance. Prior to the acceptance of a sanitary sewer by the Township, the following documents shall be submitted:

Bill of sale conveying the sanitary sewer and all appurtenances to the Township.

Construction record drawings in accordance with Article XII of these standards.

Maintenance bond in the amount of 25% of the cost of construction extending for a term of one year after conveyance to and acceptance of the sanitary sewer by the Township.

A final waiver of lien from the contractor(s) and subcontractor(s) who constructed the sanitary sewer, and the suppliers of materials used in the construction of the sanitary sewers, and a sworn statement from the proprietor of the development that all financial obligations of every nature in connection with the sanitary sewer and its appurtenances have been paid and that there are no outstanding bills, liens, judgments, etc., against the sewer system.