Design Criteria & Specs. for Gravity Sewers & Appur.

Contractor - Contractor who is installing sewer lines in a proposed development. As provided by the laws of Tennessee, he must be properly licensed in Tennessee to perform gravity sewer work.

Engineer - One who has prepared the construction plans for the installation of sewer lines in a proposed development. As provided by the laws of Tennessee, he must be a registered professional engineer in Tennessee and plans and specifications must bear his official seal. He must have demonstrated compentency in design of gravity sewage systems

State Health Department - Tennessee Department of Environment and Conservation.

1.02 SCOPE OF REGULATIONS

These regulations shall apply to any person, developer, firm, business, or entity interested in and desiring to construct additional sewer lines or to extend sewer lines within the City of Tullahoma, Tennessee, or to construct additional lines or extend sewer lines in a way that affects the sewer service provided by the City.

1.03 REFERENCES

The Engineer and Developer should be familiar with the contents of the following documents prior to plans submission to the Board:

1. “Tullahoma Utilities Board Developer Guidelines for Utilities”, available at the Board’s office.

2. “Design Criteria for Sewage Works”, latest revision, State of Tennessee, Department of Environment and Conservation, Division of Water Pollution Control.

3. Subdivision Regulations, City of Tullahoma, Tennessee, available at City Hall.

1.04 DESIGN FEATURES

Sewer system design features shall generally conform to good municipal practice and to requirements of the Tennessee Department of Environment and Conservation.

The following criteria will generally apply:

Per Capita Wastewater Flow 100 GPCD

Peak Flow Factors

Lateral Sewers 4.0 fps

Interceptor Sewers 2.5 fps

Minimum velocity at design flow 2.0 fps

Maximum velocity at design flow 15.0 fps

Basis of Hydraulic Design:

Kutter’s Formula with “n” = 0.013

Minimum Size Diameter

Collector 8”

Service 4”

Pumping stations shall, where possible, be designed to utilize equipment similar to that already utilized by the Board. Design discharge velocities shall be such as to create self-cleansing conditions in the force main. Suitable air release valves shall be utilized at all points in the force main where there is an accumulation of air or gases released from the sewage.

Pumping facilities will be required to have full standby capacity, alarm system, flow meters in some cases and elapsed time meters for all pumps in all cases, water supply for maintenance and other items as determined in reviews for individual installation. Spare parts, such as seals, contactors, floats, etc., shall be provided by the Developer, to be determined by the Board on a case-by-case basis. Pump stations must be provided with all-weather roads for access for maintenance vehicles. The developer shall provide one day (8 hours) of training by the pump manufacturer for the Board’s operation and maintenance personnel. Three copies of complete Operation/Maintenance manuals shall be provided for pump station prior to final acceptance.

Manufacturer shall inspect the installation and operation of the equipment and provide to the Board a written certification that the facilities are properly installed and operating in accordance with the requirements of the manufacturer.

Shop drawings for pump stations must be submitted to and approved by the Board (after approval by the Engineer) prior to actual purchase of the pump station equipment.

Preliminary discussions concerning pump station design are encouraged before preparation of preliminary plans so specific design requirements can be established.

Sewers crossing streams or drainage ways shall be Ductile Iron and designed to cross the stream or drainage way as nearly perpendicular to the stream flow as possible. Sufficient cover for the sewer line shall be provided to protect the line. In general, cover minimums shall be as follows:

1. One foot of concrete when sewer is located in rock;

2. Three feet when sewer is in the stabilized stream or drainage channel; and

3. Seven feet when sewer is in a shifting stream channel.

Sewers located along streams or drainage ways are to be located outside of the stream bed and sufficiently removed from the normal flow channel to minimize damage to the streamside tree and vegetation root systems. Appurtenances (i.e., manholes, etc.) shall be located and constructed such that they do not interfere with the free discharge of flood flows of the stream or drainage way.

Pipe Material shall be as designated on approved construction drawings and shall conform to applicable specifications included in Section 2 of these Standard Specifications. The Engineer shall designate pipe materials on all construction drawings.

Separation of Water Mains and Sewers shall be maintained in accordance with the following guidelines:

For parallel installations, line separation is to be at least 10 feet edge to edge. If this cannot be obtained, the bottom of the water line shall be at least 18 inches above the top of the sewer. If this condition is also unobtainable, the sewer line is to be constructed of materials and have a joint design equivalent to water main standards as approved by the Board and shall be pressure tested to 50 psi to assure watertightness.

Where the water line crosses house sewers, storm sewers, or sanitary sewers, a separation of at least 18 inches shall be provided between the bottom of the water line and the top of the sewer. If this separation cannot be obtained, sewers within 10 feet of the water line shall be constructed of materials and have a joint design equivalent to water main standards as approved by the Board. Such sewer lines shall be pressure tested to 50 psi to assure watertightness. Water mains passing under sewers shall be protected (in addition to the above sewer line construction) by providing: at least 18 inches between the bottom of the sewer and the top of the water line; adequate structural support of the sewer line to prevent excessive joint deflection or damage to the water line; centering of the water line section to result in water line joints being removed from the sewer line to the maximum possible extent. No water line shall pass through or come into contact with any part of a sewer or manhole.

Easements - When sanitary sewers are constructed outside a public right-of-way, easements must be provided using the following:

Sewer Depth (feet) Easement Width Required (minimum)

0 - 12 20 feet

12 - 20 30 feet

No sewer allowed deeper than 20 feet without special approval by the Board. Also, any sewer over 15 feet deep shall be constructed using DUCTILE IRON PIPE unless otherwise approved by the Board.

Special Construction Requirements - Special provisions and requirements shall be required when sewers are constructed along or across streams or drainage ways.

During construction activities for a project, the Contractor shall be prohibited by clauses in the project specifications, or by reference to these specifications, from any unnecessary disturbances or uprooting of trees and/or vegetation along the stream or drainage way bank or vicinity, dumping of soil and debris into or along the stream or drainage way, changing course of the stream or drainage way, or pumping silt-laden water into the stream or drainage way.

The proposed work shall be carried out in such a manner as to prevent violations of water quality standards stated in 1200-4-3-.03 of the Rules of the Tennessee Department of Environment and Conservation.

At a minimum, temporary erosion control measures such as silt fences, staked hay bales or siltation ponds shall be used to prevent or retard erosion from the construction activity from entering streams or drainage ways in the vicinity of the construction. The erosion control measures shall be in place prior to beginning clearing and/or any other construction activity.

The erosion control measure(s) used to protect the water quality of the nearby streams and/or drainage ways shall be maintained throughout the construction period. These control devices shall not be removed until, in the opinion of the Board, they are no longer required. Generally this will be at the completion of the required restoration work for the project.

Special design requirements shall be employed to prevent stream drainage from sinking at the crossing and following along the sewer pipe bedding. This can be accomplished with an in-trench impounding structure of compacted clay. Other proposals will be considered.

1.05 PERMITS

Before beginning any construction the Developer or his agents shall obtain all necessary permits as required by law. Such permits include but are not limited to those from State and County Highway Departments, the City and appropriate underground utility location services.

1.06 NOTIFICATION OF CONSTRUCTION

Before construction starts, a preconstruction conference shall be held with the Developer, Contractor, Board, and other agents as appropriate present. After this conference, the work may begin and shall be accomplished in accordance with the approved plans and specifications by a properly licensed contractor.

1.07 INSPECTION

All projects shall be subject to inspection during and upon completion of construction by an authorized representatives of the Board. Presence or absence of the inspector during the construction does not relieve the Developer and/or Contractor from adherence to approved plans and specifications.

The work shall at all times be subject to the inspection by authorized representatives of the Board and materials and/or workmanship found not meeting requirements of approved plans and specifications shall be immediately brought into conformity with said plans and specifications.

An authorized representative of the Board shall make a final inspection of the project after completion to determine acceptability of the work. Before this final inspection can be made, the Developer shall notify the Board in writing that the work has been completed in accordance with approved plans and specifications.

1.08 FINAL ACCEPTANCE

When facilities qualify as public facilities, the Board will accept ownership of the completed facilities when the work has passed the final inspection, proper acquisition documents are completed, and acceptable Record Drawings are submitted to the Board. The Record Drawings shall be completed by the Engineer responsible for the project and shall show final locations of sewer lines, manholes, valves and fittings for force mains, services, and any other items pertinent to the system. Service line location and measurements shall be from the next downstream manhole with an indication of the length of service and depth of the end of the service. For sewer service lines not perpendicular to the main, locate the end of the service from two (2) property corners.

A “Mylar” set and three (3) print sets of the Record Drawings shall be submitted to the Board before final acceptance of the work is made. The Record Drawings shall have on them a certification of accuracy signed by the project Engineer.

Final acceptance by the Board will be made in writing upon satisfactory completion of the project including final inspection, submittal of “Record” Drawings and completion of acquisition documents. The Developer shall guarantee the work for a period of one year from the date of final acceptance and shall immediately correct any deficiencies in the work due to materials and/or workmanship which occur during the guarantee period. The date of final acceptance shall be that date on which the Developer has fulfilled all conditions necessary for final acceptance.

SECTION 2 - MATERIALS

2.01 GENERAL

All materials to be incorporated in the project shall be first quality, new and undamaged material conforming to all applicable portions of these specifications.

2.02 CONCRETE

Cement - Cement shall be Portland cement and shall conform to “Standard Specifications for Portland Cement”, Type 1, ASTM Designation C150, latest revision. Cement shall be furnished in undamaged 94 pound, one cubic foot sacks, and shall show no evidence of lumping.

Concrete Fine Aggregate - Fine aggregate shall be clean, hard uncoated natural sand conforming to ASTM Designation C33, latest revision, “Standard Specifications for Concrete Aggregate”.

Concrete Course Aggregate - Course aggregate shall consist of clean, hard, dense particles of stone or gravel conforming to ASTM Designation C33, latest revision, “Standard Specifications for Concrete Aggregate”. Aggregate shall be well graded between 1-1/2” and #4 sieve sizes.

Water - Water used in mixing concrete shall be clean and free from organic matter, pollutants and other foreign materials.

Ready-Mix Concrete - Ready-mix concrete shall conform to ASTM Designation C94, latest revision, “Specifications for Ready-Mix Concrete”.

Class “A” Concrete - Class A concrete shall have a minimum compressive strength of 4000 pounds per square inch in 28 days and shall contain not less than 6 sacks of cement per cubic yard.

Class “B” Concrete - Class B concrete shall have a minimum compressive strength of 2000 pounds per square inch in 28 days and shall contain not less than 4-1/2 sacks of cement per cubic yards.

Metal Reinforcing - Reinforcing bars shall be intermediate grade steel conforming to ASTM Designation A15, latest revision, “Standard Specifications for Billet Steel Bars for Concrete Reinforcement”. Bars shall be deformed with a cross sectional area at all points equal to that of plain bars of equal nominal size.

2.03 CRUSHED STONE

Crushed stone for bedding or backfill shall be Tennessee Department of Transportation (TDoT), Bureau for Highways, Standard Size No. 67 and shall meet TDoT Standards for road surfacing.

2.04 PEA GRAVEL

Pea gravel for shaping cradle bedding shall be #4 to #1/2” size Ohio River, or approved local gravel of similar character.

2.05 MANHOLE FRAMES AND COVERS

Manhole castings shall conform to ASTM Designation A48, latest revision, Class 20 and shall be free from scale, lumps, blisters, sand holes and defects of every nature which would impair their use. Castings shall be well cleaned, with a smooth tough asphaltic coating. Covers shall be well cleaned, with a smooth tough asphaltic coating. Covers shall be of the solid indented type with the words “SANITARY SEWER” cast in raised letters thereon. Bearing Surfaces of frames and covers shall be machined to provide a solid bearing and prevent rocking. Pattern drawings and weights of castings shall be submitted for approval of the Board.

Manhole frames and covers shall be equal to those listed below for particular applications.

TRAFFIC John Bouchard No. 1155

NON-TRAFFIC Same as traffic type specified above.

WATERTIGHT To be used where manhole casting is subject to flood

or submergence by surface runoff.

John Bouchard No. 1123

Exceptions to the above shall be noted on Construction Drawings.

2.06 MANHOLE STEPS

Manhole steps are neither required nor permitted.

2.07 PRECAST MANHOLES

Precast manholes shall conform to the latest revision of ASTM C-478. Drawings of manhole sections proposed for use on this project must be submitted to the Board for approval prior to use.

Manhole sections showing evidence of cracking, crazing, honeycombing, crumbling or excessive roughness will not be acceptable. Sections with improper cut-outs, misalignments or other defects shall not be utilized in the project.

Precast manhole panel (monlithic) bases may be used. Drawings of the monolithic bases proposed for use on this project must be submitted to the Board for approval prior to use. Bases shall have a minimum thickness of 8 inches with a minimum thickness of 2 inches allowed at the invert of the downstream pipe for the construction of the invert. All inverts shall be formed in the field by the Contractor.

Manhole sections shall be steam or water cured and shall not be delivered to job site until at least 7 days old. Each section shall be marked in a permanent manner with date of manufacture, manufacturer’s mark, and manhole location or manhole number. Manhole sections to receive pipes shall be furnished with appropriate cut-outs with resilient connectors for installation of pipe. Joints of manhole sections shall be of tongue and groove type.

On precast manhole sidewall an approved flexible plastic gasket equal to RAM-NEK shall be applied to the joint surface to placement of next manhole section. The placement of this gasket shall also be required under all manhole castings and adjustment rings for castings, both on inside and outside edges.

Testing and Inspection of precast manhole sections shall be done in accordance with ASTM C-478 by an independent testing laboratory suitable to the Board. Compression tests shall be run on specimens obtained from each day’s production: a minimum of 2 cylinders or cores per day’s run but no less than the maximum number designated by ASTM C-478. The absorption test shall be run on a minimum of 2 randomly selected manhole sections per each day’s production.

2.08 MONOLITHIC POURED-IN-PLACE MANHOLES

Concrete shall be Class D design mix. Also for each day’s pour two test cylinders should be made and tested in compliance with ASTM 172, ASTM C31 and ASTM C39. These testings shall be done by a testing laboratory selected, employed and paid for by the Contractor.

The Contractor shall submit to the Board his choice of a testing laboratory for their approval. The Contractor shall instruct the testing laboratory to forward copies of the test reports to the Board.

The maximum depth of manholes shall not exceed twenty feet. The minimum wall thickness for 4’-0” inside diameter manholes shall be 6 inches. The minimum wall thickness for 5’ and 6’ in size diameter manholes shall be 8 inches.

The base concrete shall be Class D as stated above, vibrated on firm sub-grade foundation or suitable crushed stone bedding. The base shall have a minimum diameter 8 inches greater than the outside diameter of the manhole and a minimum thickness, including the area under the pipe, as follows:

0’ to 8’ Manhole 8”

8’ to 12’ Manhole 10”

12’ to 20’ Manhole 12”

All water shall be removed from the form before and during the placement of the concrete. The first placement of base concrete shall consist of approximately 1/2 cubic yard of concrete deposited evenly around the walls and vibrated until there is a minimum slope of 60 degrees from the bottom of the forms to the bearing surface both inside and outside of the manhole. When this is complete and before additional is added, the concrete must be carefully vibrated on each side of each pipe.

Additional concrete must be deposited in evenly distributed layers of 18 inches with each layer vibrated to bond to the preceding layer. The wall spacers must be raised as the placements are made with the area from which the spacer is withdrawn being carefully vibrated.

Should a cold joint become necessary, a formed groove and reinforcing dowels (#5 bars 36 inches long at 12 inch centers) will be required in the top of the first placement for shear protection. Immediately before the second placement is made, the surface of the cold joint shall be thoroughly cleaned and wetted with a layer of mortar being deposited on the surface.

Felt adjustment rings will be formed and/or poured into the top section of the manhole to provide future manhole casting adjustments equal to two course of brick

The forms may be removed 24 hours after placement. At this time a membrane curing compound with a fugitive dye included will be applied by power spraying to the outside of the manhole. The Contractor must submit manufacturer’s descriptive details for curing compounds for approval.

The monolithic manholes shall be backfilled to the same level simultaneously all around. The manholes shall not be backfilled until they reach 75% of the specified design strength. A select gravel backfill material shall be placed adjacent to the manholes in areas where swelling clays exist.

A resilient pipe connector shall be utilized to connect pipe to manhole sidewall.

Eccentric manhole cones shall be furnished and installed for 5 and 6 foot diameter manholes on precast or poured-in-place manholes. Concentric manholes cones may be installed on 5 and 6 foot diameter manholes if transition sections are used from 5 or 6 foot diameter to 4 foot diameter at approximately 60 inches above pipes. Details of proposed manhole construction shall be submitted to Board for approval.

Manholes shall be coated on outside after fully cured with two coats of bituminous paint applied at right angles.

2.09 RESILIENT CONNECTORS

All connections of pipes to manholes sidewalls shall be made with resilient connectors. Openings in the manhole sidewall shall be so constructed such that it is an integral part of the sidewall and to provide for the required size and location of the pipe to connect to the manhole. The sidewall opening shall be manufactured to allow for lateral and vertical movement, as well as angular adjustments through 20 degrees. The resilient connector shall be Kor-N-Seal as manufactured by NPC, Inc., or approved equal. The resilient connector shall meet all physical and performance requirements as set forth by ASTM C-923. Any exposed metal, such as tightening bands, shall be made entirely of corrosion resistant stainless steel. The void between the pipe and connector shall be filled with the “Cavity-O-Ring” annular space filler as manufactured by NPC, Inc., or approved equal.

2.10 DUCTILE IRON SEWER PIPE

1. Material

Ductile iron sewer pipe shall conform to ASA Spec. A21.51 for ductile iron pipe centrifugally cast in metal or sand lined molds. Laying lengths shall be 16 feet or longer, except for special construction conditions. Pipe shall have bituminous coating outside, cement lining inside - ASA 21.4, and bituminous coating inside. Pipe shall be made with 60-42-10 grade ductile iron, or stronger. Unless noted otherwise on Drawings, thickness Class 50 pipe shall be used for gravity lines.

2. Drawings

Unless otherwise indicated on the construction Drawings, ductile iron pipe may utilize slip-on joints equal to Tyton or Fastite. Joints used must be approved by the Board.

3. Testing and Inspection

Testing and inspection shall be accomplished at the factory in accordance with ASA A21.51. An independent testing laboratory approved by the Board shall perform tests and furnish the Board with two (2) copies of all test reports. Tests to include: hydrostatic test (500 PSI - 10 Sec.); tensile test and impact test with one sample to be taken during each period of approximately three (3) hours. (See Section 2.13)

4. Marking

The weight, class, manufacturer’s mark, year of manufacture and letters “DI” or “DUCTILE” shall be cast or stamped on pipe.

2.11 POLYVINYL CHLORIDE (PVC) SEWER PIPE

1. Materials

PVC sewer pipe shall be SDR 35, or heavier, manufactured in accordance with ASTM D3034, latest revision, for type PSM sewer pipe and fittings, 4” through 15”. ASTM F679 (wall thickness T-1), 18” through 27”. Pipe shall be furnished in lengths not to exceed 13 feet. Pipe shall be furnished with integral bells; gaskets and lubricants shall be furnished by the pipe manufacturer. Pipe and fittings shall be made of PVC plastic having a cell classification of 12454-B or 12454-C as defined in ASTM D-1784.

Pipe manufacturer shall be approved by the Board before use on any project.

2. Joints

Joints shall be compression type utilizing an elastomeric gasket providing a positive seal against ground water and root intrusion as well as sewage leakage and shall be in accordance with ASTM D3212. Gaskets shall comply with physical requirements specified in ASTM F447, latest revision. Lubricant shall be furnished with gasket and entirely compatible with gasket and pipe material.

Joints shall show no signs of leakage when tested as follows (supersedes ASTM D3034): Typical joint assembly shall be subjected to internal hydrostatic pressure of 10.8 psig for 10 minutes without leakage; assembly shall also be subjected to internal vacuum of twenty-two (22) inches of mercury or external pressure of 10.8 psig for ten (10) minutes without leakage. The above internal pressure and vacuum or external pressure tests shall be run on a typical joint assembly in concentric alignment and in a position of angular deflection to at least. three (3).

Joint design shall be approved by the Board before use on any project.

3. Testing and Inspection

Testing and inspection of all pipe shall be done at the factory with a certified copy of test results furnished to the Board before any pipe is installed.

For projects using less than 2000 feet of sewer (not including service lines) such testing shall be done by the manufacturer. For larger projects, testing shall be done by an independent testing laboratory approved by the Board (unless this requirement is waived in writing by the Board, in which case testing shall be done as if for projects using less than 2000 feet of sewers.)

Tests shall be done in accordance with ASTM D-3034 or ASTM F-679 and shall include: Pipe and Fitting Dimensions; Pipe Flattening; Impact Resistance; Pipe Stiffness; Joint Tightness (see Part 2); and Extrusion Quality. At least 1% of the production of each size furnished for this project shall be tested.

4. Marking

Each pipe section shall be marked with the following information:

4” to 15”:

Manufacturer’s name or trademark; nominal pipe size; PVC cell classification; Legend “Type PSM DR 35 PVC Sewer Pipe”; ASTM D3034.

18” to 27”:

Manufacturer’s name or trademark; nominal pipe size; PVC cell classification; Legend “PS 46 PVC Sewer Pipe”; ASTM F679.

5. Installation

Installation of PVC sewer pipe shall follow requirements of Section 3.

2.12 CONCRETE PIPE AND OTHER PIPE MATERIALS

Concrete pipe, if desired, shall be allowed only for sizes 15” diameter and greater. The Engineer shall submit proposed concrete pipe material, fittings and pipe laying specifications for Board review and approval during the design phase of the project.

Generally, use of pipe materials other than PVC, Ductile Iron, and Concrete shall not be permitted. If the Contractor or Engineer desires to use other pipe materials, the Board must be approached early in the design phase of the project. The decision of the Board on the use of other pipe materials shall be final.

2.13 FITTINGS AND COUPLINGS

Unless otherwise indicated or directed by the Board, fittings shall be of the same material as the pipe line in which they are to be installed. Fittings shall be furnished with joints of the same type used throughout the rest of the pipe line unless such joint shall not be available and the Board should approve a substitute type joint. Fittings shall be of the type indicated on the drawings and shall be the manufacturer’s standard conforming to all applicable standard specifications and dimensional tolerances appropriate for the material of construction.

2.14 SPECIAL NOTE ON TESTING AND INSPECTION

The requirement that materials testing be done by an independent testing laboratory approved by the Board is hereby waived unless specifically required by the Board as noted during plan review. Tests as indicated must be conducted, however, and the Board shall be furnished with test reports as indicated. The test reports shall be certified true by the manufacturer.

SECTION 3 - CONSTRUCTION

3.01 GENERAL

The streets, roads, and easements in which lines will be placed shall be indicated on the plans. Any change from locations approved by the Board shall be approved by the Board before construction.

Where the excavation exceeds the required depth, the Contractor shall bring the excavation to proper grade through the use of an approved incompressible backfill material (generally crushed stone or fill concrete, depending upon the nature of the facility to be placed thereon). In the event unstable soil conditions are encountered at the bottom of the excavation, the Engineer will direct the Contractor to continue the excavation to firm soil or to provide pilings or other suitable special foundations, with such action subject to approval by the Board.

The Contractor shall take such precautions as may be necessary to avoid endangering personnel, pavement, adjacent utilities or structures through cave-ins, slides, settlements or other soil disturbances resulting from his operations.

Backfilling shall be carried out as expeditiously as possible, but shall not be undertaken until the Board’s inspector has been given the opportunity to inspect the work. The Contractor must carry out all backfilling operations with due regard for: the protection of pipes, structures and appurtenances; the use of prescribed backfill materials; and procedures to obtain the desired degree of compaction.

All shade trees, telephone poles, power poles, etc., along the line of work shall be protected, and sufficient barricades, lanterns, etc., shall be provided for the protection of the public.

3.02 TRENCH EXCAVATION

3.02.1 General - Trenching must be done in a neat and workmanlike manner maintaining proper vertical and horizontal alignment. Alignment shall be maintained by the use of offset hubs and batter boards at maximum 50 foot intervals or with a laser device or with other methods approved by the Board. Cut sheets shall be submitted to the Board for approval prior to construction.

Trenching shall be neatly excavated to the alignment and depth required for the proper installation of pipe, bedding material and appurtenances. Trenches shall be opened up far enough ahead of pipe laying to reveal obstructions, but in general shall not include more than 300 feet of continuous open trench at any time. The Contractor will be required to follow up trenching operations promptly with pipe laying, backfill and clean-up, and in event of failure to do so, may be prohibited from opening additional trench until such work is completed. This requirement is particularly applicable to work being done in developed areas.

The Contractor shall plan his operations so as to cause a minimum of inconvenience to property owners and to traffic. No road, street or alley may be closed unless absolutely necessary, and then only if the following conditions are met:

1. Permit is secured from State, County, or Municipal authorities having jurisdiction.

2. Fire, Police, Public Works Departments are notified before roads are closed.

3. Suitable detours are provided and are clearly marked.

No driveways shall be cut or blocked without first notifying the occupant of the property. Every effort shall be made to schedule the blocking of drives to suit the occupants convenience, and except in case of emergency, drives shall not be blocked for a period of more than eight (8) hours. The Contractor shall furnish and maintain barricades, signs, flashing lights, and other warning devices as necessary for the protection of public safety. Flagmen shall be provided as required on heavily traveled streets to avoid traffic jams or accidents.

Trench width shall be held to a minimum consistent with proper working space for assembly of pipe. Maximum trench width up to a point one foot above top of pipe shall be limited to the outside pipe diameter plus sixteen (16) inches. Boulders, large stone, shale and rock shall be removed to provide clearance of 6” below and on each side of the pipe. Trench walls shall be kept as nearly vertical as possible with due consideration to soil conditions encountered and when necessary, sheeting or bracing shall be provided to protect life and property. Where unstable soil

conditions are encountered at the trench bottom, the Contractor shall remove such additional material and replace the excavated material with approved backfill, or otherwise provide stable bedding for pipe as approved by the Board.

The Contractor shall excavate by hand wherever necessary to protect existing structures or utilities from damage or to prevent overdepth excavation in the trench subgrade.

Excavated material shall be stored safely away from edge of trench and in such a way as to avoid encroachment on private property.

3.02.2 Rock Excavation - Where rock is encountered the excavation shall be carried to a depth of 6” below the barrel of the pipe, or the bottom of the structure, and the excess excavation shall be backfilled with crushed stone, sand or other approved bedding material firmly compacted. Boulders and large stones, rock or shale shall be removed to provide a clearance of at least 6” below all parts of the pipe or fittings and to clear width of at least 6” on each side of pipe and appurtenances.

Where rock is encountered, the Contractor shall “mattress” the trench during blasting operations and shall use all precautions to protect adjacent property against damage resulting from his operations. Rock excavation in proximity to other pipes or structures shall be conducted with the utmost care to prevent damage to the existing structures and any such damage caused shall be promptly repaired at the Contractor’s expense. Blasting operations shall not be conducted within 25’ of finished sewer or water pipe and rock excavation shall be at least 25’ ahead of pipe laying.

Extreme care shall be exercised in blasting with signals of danger given and displaced before the firing of any charge. The Contractor shall, in all his acts, conform to and obey all rules and regulations for the protection of life and property that may be imposed by any public authorities or that may be made from time to time by the Engineer relative to the storing and handling of explosives and the blasting operations. No blasting shall be done at any time except by persons experienced in this line of work.

Where rock is encountered in the immediate vicinity of gas mains, telephone cables, building footings, gasoline tanks, or other hazardous areas the Contractor shall remove the rock by means other than blasting. Care shall be taken in blasting operations to see that pipe or other structures previously installed are not damaged by blasting.

3.02.3 Sheeting and Shoring - The Contractor shall provide such bracing, sheeting or shoring as may be necessary for the protection of life and property, or where such protection is specifically required by the Engineer because of potential danger to life, property or the completed structure. It is the responsibility of the Contractor, Engineer, and Developer to provide proper design and implementation of excavation protection systems in accordance with applicable OSHA standards. The Board will not assume responsibility of, nor will the Board inspect excavation protection systems. Sheeting will be required where necessary to restrict the trench width to acceptable limits above the top of pipe.

Sheeting, shoring or bracing shall conform to applicable safety codes and shall be left in place until pipe is laid, checked, and backfilled to a safe level at or above top of pipe. The bracing or sheeting may then be removed in an approved manner unless the Engineer specifically directs that the sheeting be left in place. Where the sheeting is left in place, either at the direction of the Engineer or option of the Contractor, the sheeting shall be cut off at least 18” below the finished ground level.

Care shall be taken in removing sheeting to avoid weakening the trench, increasing the backfill load, or endangering adjacent property. Voids left by the removal of sheeting shall be filled in and compacted with suitable material using tamps intended for this purpose.

3.02.4 Surface Obstructions - All buildings, walls, fences, poles, bridges, railroads, trees, and other property or improvements encountered shall be carefully protected from all injury, and in the event that any of the foregoing are damaged or removed during the process of the work, they shall be repaired or replaced in a satisfactory manner. Special care must be exercised in trenching under or near railroads in order to avoid or minimize delays or injuries resulting therefrom. Where it is necessary to cross beneath railroad tracks, the Contractor shall make such installations in a casing of large diameter as approved by the Railroad Company and the Board.

3.02.5 Subsurface Obstructions - In excavating, backfilling, and laying pipe, care must be taken not to remove, disturb, or injure other pipes, conduits, or structures, without the approval of the owner(s) of said facilities. If necessary, the Contractor, at his own expense, shall sling, shore up and maintain such structures in operation, and within a reasonable time shall repair any damage done thereto. Repairs to these facilities shall be made to the satisfaction of the owner(s) of said facilities.

The Contractor shall give sufficient notice to the interested utility of his intention to remove or disturb any other pipe, conduit, etc., and shall abide by their regulations governing such work. In the event subsurface structures are broken or damaged in the prosecution of the work, the Contractor shall immediately notify the proper authorities and shall be responsible for any damage to persons or property caused by such breaks.

When pipes or conduits providing service to adjoining buildings are broken during the progress of the work, the Contractor shall have them repaired at once. Delays, such as would result in buildings being without service overnight or for needlessly long periods during the day, will not be tolerated, and the Board reserves the right to make repairs at the Contractor’s expense without notification. Should it become necessary to move the position of the pipe, conduit, or structure, it shall be done by the Contractor in strict accordance with instruction given by the utility involved.

3.03 INSTALLATION OF SEWER PIPE AND ACCESSORIES

3.03.1 General - The Contractor shall use only experienced people in the final assembly of pipe in the trench, and all pipe shall be laid in accordance with these Specifications and the recommended practice of the pipe manufacturer. Trench bottoms shall be carefully prepared, shall be free of water, and bedding as specified shall be in place.

Care shall be exercised to insure that pipe of the proper strength or classification meeting the specifications in every respect is provided at the site of pipe laying operations. Recommended tools, equipment, lubricant and other accessories needed for proper assembly or installation of the pipe shall be provided at the site of the work. Any damage or defective pipe discovered during the pipe laying operations shall be discarded and removed from the site of the pipe laying operations.

Alignment and grade shall be carefully maintained during the laying operations. The method used for maintaining grade and alignment must be acceptable to the Board and must produce the desired results. The top of the bedding material must be brought to the exact grade and must be shaped so as to provide effective support for the bottom quadrant of the pipe except at the bells.

The Contractor shall exercise care in the storage and handling of pipe, both on the storage yard and at the site of laying operations. Suitable clamps, slings, or other lifting devices shall be provided for handling pipe and fittings. Pipe and fittings shall be inspected for defects and for dirt or other foreign material immediately before placing them in the trench. Suitable swabs shall be available at the site of laying operations, and any dirt or foreign material shall be removed from the pipe before it is lowered into the trench.

3.03.2 Bedding - It is desired that trench widths from a point one (1) foot above the top of the pipe down to the bottom of the trench be held to a minimum consistent with the provisions of necessary space for proper assembly of the pipe. In general, the trench width shall not exceed the nominal pipe diameter plus sixteen (16) inches.

A minimum of 6” of crushed stone bedding shall be placed in the bottom of the trench to provide continuous support of the bottom quadrant of the pipe. The Contractor shall bring the crushed stone bedding up to the required level to provide support to the bottom quadrant and shall then shape the bedding to receive the pipe. Bellholes shall be dug so that the bottom of the bells will not support the pipe.

After the bedding has been shaped and the pipe has been installed, crushed stone backfill shall be carefully placed by hand and compacted on both sides of the pipe and up to a level 12” above the top of the pipe.

In addition to maximum trench width, the selection of pipe has been based on the use of 6” of crushed stone bedding to provide continuous support of the bottom quadrant of the pipe plus crushed stone backfill carefully placed and compacted on both sides of the pipe and up to a level of 12” above the top of the pipe. It is, therefore, essential that these conditions be observed in the installation of the pipe.

3.03.3 Pipelaying - After the pipe has been cleaned and inspected for defects and lowered into the trench, the mating surfaces of the compression joint shall be wiped clean and coated with lubricant of a type supplied by the pipe manufacturer. The pipe shall then be assembled with due care being taken to insure that the spigot end of the pipe is shoved home and that the pipe is left in proper grade and alignment.

Whenever pipe laying operations are to be discontinued for a period of time exceeding two (2) hours, the end of the pipe shall be carefully secured to avoid displacement or misalignment of a tight fitting plug or stopper shall be placed in the line. Upon resumption of laying operations, the plug or stopper shall not be removed from the line until any water, mud or other debris has been removed to avoid entry into the completed section of the sewer.

Installation of sewer pipe shall conform to provisions of these specifications and recommendations of the pipe manufacturer. Installation instructions provided by the pipe manufacturer shall be available at all times at the location of the work.

The proper gaskets and lubricants shall be furnished by the pipe manufacturer and lubricants shall be delivered to the job site in properly labeled, unopened containers.

Wye branches or tees and other fittings shall be placed in the sewer line as shown on the Drawings or as directed by the Board as pipe laying progresses. The Contractor shall keep accurate records of their locations.

A. Laying Polyvinyl Chloride Pipe (PVC)

Installation of polyvinyl chloride pipe shall conform to ASTM 2321, latest revision. PVC pipe shall be laid on crushed stone bedding and shall be backfilled with compacted crushed stone around and above the pipe as outlined in 3.03.2 and in 3.06.1. The bedding material shall be shaped to provide continuous support for the PVC pipe throughout its length except at bells. Blocking shall not be used to bring the pipe to grade.

Whenever it is necessary to cut a joint of pipe in order to fit the trench conditions, the cutting may be made with either hand or mechanical saws or plastic pipe cutters. The cut shall be square and perpendicular to the pipe axis. The cut end shall be beveled to as closely resemble the factory bevels as possible.

Assemble all joints in accordance with recommendations of the manufacturer.

B. Laying Ductile Iron Pipe

Where ductile iron pipe is shown, specified or directed by the Engineer, the pipe shall be of the type and class as indicated. Ductile iron pipe to be installed in trenches shall be laid on crushed stone bedding and shall be backfilled with compacted crushed stone around and above the pipe as specified for other pipe materials. The bedding materials shall be shaped to provide continuous support throughout its length except at bells.

Unless otherwise indicated, ductile iron pipe shall be laid with slip type compression joints, equal to the manufacturer’s standard for pressure water pipe and assembly of the joints shall be in accordance with the manufacturer’s recommendations using lubricant and accessories as provided by the pipe manufacturer.

Whenever it is necessary to cut a joint of pipe in order to fit the trench conditions, the cutting shall be done using the equipment as recommended by the manufacturer for the specific type of pipe involved. The cut shall be made so as to leave a smooth end at right angles to the axis of the bore and the end shall be beveled or finished as required to make the joint without risk of damage to the gasket.

On stream crossings, ravines, shallow cuts and other locations where pipe will not be laid on bedding placed on original subgrade the pipe shall be supported on concrete piers as detailed on the Drawings or as directed by the Engineer. Piers shall be of Class A concrete with reinforcing as shown. The tops of piers shall be carefully set at the exact elevation and shall be shaped so as to provide support for the bottom half of the pipe with allowance being made for the outside diameter of the pipe plus the thickness of a layer of tarred felt around the outside of the pipe. After the concrete has obtained satisfactory strength the ductile iron pipe may be installed across the piers using one or more layers of felt between the surface of the concrete and the outside diameter of the pipe. The Contractor may, at his option, install the pipe to exact grade and alignment using temporary support and then construct the permanent piers for the pipe, provided suitable precautions are taken to avoid any misalignment during the construction of the piers. Sewer laid on piers across ravines or streams shall be allowed only when it can be demonstrated that no other practical alternative exists. The impact of flood water and debris associated with these flood waters shall be considered in the design of these sewers. The bottom of the pipe on piers should be placed no lower than the elevation of the fifty (50) year flood plain.

C. Connections to Structures

Connections of pipes to manholes or other large structures shall be made using short lengths of pipe to avoid stressing the pipe at the point where it is placed in the wall of the structure. Pipes entering or leaving masonry or concrete walls shall have one flexible joint located not more than 6” outside the structure wall followed by a length of pipe not more than 2’ in length with another flexible joint at the end of the 2’ pipe length in such a way as to provide for limited lateral or vertical movement of the pipe line as well as limited deflection. Ordinary compression type joints of the types specified for gravity sewers shall be considered as having sufficient flexibility for this purpose. The supplier of the pipe for the sewer lines shall furnish with the pipe order the required number of specials and short lengths of pipe for the Contractor to install the required flexible connections without improvising.

The connection to a manhole shall be made utilizing a “Kor-N-Seal” connector, or approved equal, with the annular space filled with a “Cavity-O-Ring” filler, or approved equal. See Section 2.09 for complete specifications.

D. Connections to Existing System

No pipe shall be connected to the existing sewage system until all new upstream construction has been completed, is free of foreign materials and obvious defects have been corrected. New lines, then, must remain disconnected from the existing system by actual physical separation, by plugs of a type approved by the Board or by other means approved by the Board. A note on the construction plans stating this requirement shall be required for approval of the plans.

3.04 MANHOLES

Consideration will be given to the use of either cast-in-place manholes or precast manholes. In the event the Contractor elects to use precast manholes, he shall submit details of the proposed manholes together with the name of the supplier to the Board for approval before any of the precast manholes are shipped to the job site. Precast manholes may be used with precast floors, or with structural concrete floors poured in place. Precast risers shall be furnished with openings for pipes entering and leaving the manhole. Individual riser sections shall be furnished for the exact conditions to be encountered in the field and shall be constructed so as to suit field conditions and to line up properly with the pipes in other riser sections. Misalignment of or improperly located holes for incoming pipes shall be cause for rejection of the manhole sections. Precast manhole sections shall be joined together in such a way as to present a smooth uniform joint which shall be structurally sound and watertight.

The manhole sidewall shall be of a length such that a maximum of three (3) precast manhole casing rings (12” total), shall be placed on the top of the unit to bring the casting to final grade.

Cast-in-place manholes shall be constructed on structural concrete slabs, with a second floor incorporating flow channels being provided after the pipes have been laid and the walls have been constructed. Flow channels shall consist of smooth uniform cross sections conforming to the cross section of the pipes so as to provide a minimum of turbulence and avoid deposition of solids. Flow channels shall have a depth at least equal to one-half (1/2) the pipe diameter. The finished floor of the manhole shall have a slope approximately one-half inch (1/2”) from wall to channel to provide for proper drainage, but at the same time, offer safe footing for workmen. Brick or pieces of brick may be used for fuller material in forming the flow channel and finished floor in the manholes provided no brick shall be left within one-inch (1”) of the finished surface.

The outside surface of all manhole, precast or cast-in-place, shall be coated with two layers of bitumasitc coating applied at right angles to each other.

Care shall be taken in the construction of manholes as all manholes shall be subjected to and shall pass a vacuum test prior to acceptance. Manhole vacuum testing shall be accomplished prior to backfilling of the manhole.

3.05 SERVICE CONNECTIONS

Sewer service lines shall be provided as shown on the plans or as directed by the Board. Service connections shall consist of a wye with 4” branch connection, 4” bends, and 4” piping as required to complete the sewer service connection. Bends greater than 45 degrees are not permissible. Pipe and fitting joints shall be compression type as used on the main sewer. Service pipe and fittings shall be of the same material as used for the main sewer. Service pipe shall be laid on a slope of one-forth inch (1/4”) per foot or, where this grade is not available and the Board specifically approves, one-eighth inch (1/8”) per foot may be used. Sewer service lines shall conform to details as shown on Standard Detailed Drawings and shall terminate one foot (1’) inside the property line, or the public access easement (if service crosses this easement) with a clean-out kit installed, plastic service box brought to final grade, and service line properly capped. The service end shall be capped with a tight compression plug braced to withstand pressure of an air pressure test. (See Standard Detail S-6 for particulars.)

In the event that it should be necessary to install a service connection where a wye has not been provided, saddles must be used and shall be a