City of Byrnes Mill, MO Installation

Excavation work shall be performed in a safe and proper manner, with suitable precautions being taken against hazards of every kind. Excavations shall provide adequate working space and clearances for the work to be performed herein.

Mechanical excavation of the trench shall be to four (4) inches below the invert of the pipe. The trench bottom shall be dry when excavated, then filled with granular material to the pipe spring line. The granular material shall be prepared to receive the pipe barrel and bell holes shall be excavated to relieve the bell from bearing.

Where a firm foundation is not encountered in the trench bottom due to soft, spongy or other suitable soil, unless other special construction methods are called for on the plans, all such unsuited soil under the pipe and for the width of the trench shall be removed and replaced with granular backfill.

Section 510.120 Pipe Installation.

[R.O. 2011 §510.120; Ord. No. 028-87 §4-19.3, 5-6-1987]

Pipe shall be protected during handling against impact shocks, and shall be kept clean at all times and no pipes shall be used in the work that do not conform to the appropriate specifications. The Contractor shall keep the trench free from water while the sewer is being placed and until the joint has been sealed to the satisfaction of the Engineer. The laying of pipes in finished trenches shall be started at the outlet and with the spigot ends pointing in the direction of flow. The pipes shall be lowered so as to avoid unnecessary handling in the trench.

As each length of pipe is laid, the mouth of the pipe shall be properly protected to prevent the entrance of earth of the bedding material. All pipe shall be laid with ends abutting and true to line and grade. They shall be carefully centered, so that when laid in the work they will form a sewer with a smooth uniform invert.

Preparatory to making pipe joints, the joint material on both the bell and spigot ends shall be thoroughly cleaned and coated with the proper lubricant or cement to facilitate assembly. The spigot end shall be inserted in the bell and pressure applied until the pipe is properly sealed.

Plugs for pipe branches, stubs, or other open ends which are not to be immediately connected shall be made of an approved material and shall be secured in place with a joint comparable to the main line joint, or stoppers may be of an integrally cast breakout design. Plugs shall be capable of withstanding all test pressures without leakage.

If the contractor so desires, he/she may use granular backfill to a level of one (1) foot above the top of the pipe as a substitute for the required careful tamping.

Section 510.130 Backfill.

[R.O. 2011 §510.130; Ord. No. 028-87 §4-19.3, 5-6-1987]

Except as noted on the plans or may otherwise be specified herein or specified by the pipe manufacturer, backfill material to twelve (12) inches above the extrados of the pipe may be natural earth removed from the trench which, in the opinion of the engineer, is suitable for backfilling. This backfill shall be free of cinders, ashes, refuse, vegetation, or organic matter, frozen earth, debris, large pieces of fragments of inorganic or inert matter. Suitable earthen backfill shall be carefully deposited in uniform four (4) inch layers (loose measure) simultaneously on both sides of the pipe, in such a manner that injurious side pressures to the pipe do not occur; then carefully and uniformly tamped in place, so as to eliminate the possibility of lateral displacement of the pipe. Where suitable natural earth backfill is not available from the trench excavation, a suitable off-site earth backfill or a selected granular material may be substituted. Refer to Section 510.070 for granular backfill specifications. When using a granular backfill material, said granular shall be topped to grade with a twelve (12) inch thick layer of top soil.

Backfill above the level one (1) foot above the extrados of the pipe shall be made by any acceptable method which will not dislodge or damage the pipe or cause bridging action in the trench. Selected trench excavation material, free from frozen earth, foreign material, or spheres larger than eight (8) inches across, may be used where such material does not interfere with obtaining compaction of the trench.

Trenches in areas of existing streets, driveways, parking areas, sidewalks, or permanent type pavements shall be backfilled full height to the bottom surface of the permanent type surface with material specified for granular backfill.

Section 510.140 Manhole Construction.

[R.O. 2011 §510.140; Ord. No. 028-87 §4-19.3, 5-6-1987]

Manholes shall be pre-cast concrete. Manhole frames and covers shall be of cast iron as shown on the drawings in Article IV.

Pre-cast manholes may be constructed with a pre-cast base section or a monolithic base structure.

A pre-cast base section shall be carefully placed on the prepared bedding so as to be fully and uniformly supported in true alignment and making sure that all entering pipes can be inserted on proper grade.

All lift holes on pre-cast elements for sanitary sewer manholes shall be completely filled with an approved bitumastic material. All joints between pre-cast elements on sanitary sewer manholes shall be made with a pre-molded mastic gasket or an approved rubber gasket. The exterior of the manholes shall be waterproofed with a bitumastic coating.

The first pre-cast section shall be placed on the monolithic base structure before the base has taken initial set, and shall be carefully adjusted to true grade and alignment with all inlet pipes properly installed so as to form an integral, water-tight unit; or the section shall be mortared into a suitable groove provided in the top of the monolithic base. The first section shall be uniformly supported by the base concrete, and shall not bear directly on any of the pipes.

Pre-cast sections shall be placed and aligned to provide vertical sides and vertical alignment of the ladder rungs. The completed manholes shall be rigid, true to dimensions, and be water-tight. Manhole inverts shall be carefully constructed to maintain the proper velocities through the manhole, and in no case shall the invert sections through the manhole be greater than that of the outgoing pipe. The shape of the invert shall conform exactly to the lower half of the pipe it connects. Side branches shall be connected with as large radius of curve as practicable. All inverts shall be plastered and troweled to a smooth clean surface.

The main sewer shall be carried through manholes by split pipe wherever practicable. Concrete filling between the sewer invert and walls of manholes shall be flush with the top edges of the invert and shall slope up from the invert at the rate of three (3) inches per foot.

Backfilling shall be done carefully with selected earth fill, free from rocks and debris, without damage to the manhole.

Section 510.150 Acceptance Test.

[R.O. 2011 §510.150; Ord. No. 028-87 §4-19.3, 5-6-1987]

Upon completion of the sewers, acceptance tests will be conducted by the contractor, in the presence of the design engineer of record and a representative of the Building Commission to determine the acceptability of the sewers. The testing schedule shall be submitted to the design engineer by the contractor prior to testing. The contractor shall furnish suitable test equipment, materials, and manpower to conduct the test.

All completed pipe sewers shall be subject to an exfiltration test. The sewer pipe shall sustain a minimum limit of two hundred (200) gallons per inch of diameter per day per mile with a two (2) foot minimum head. The exfiltration test shall cover a period of at least four (4) continuous and consecutive hours.

No ground water in an amount greater than that allowed and specified herein for the exfiltration test shall be permitted.

Any completed pipe sewers not conforming to the tests herein specified or conforming to all requirements of the project design specifications, plans, and profiles, or subject to any irregularity of construction shall be removed and replaced and retested.

The contractor shall cooperate fully with the design engineer and the Building Commission for the inspection and testing of the completed work.

Stoppers or plugs for the various sizes of pipe shall be furnished by the contractor for use in the tests and personnel shall be made available by this contractor for aid in conducting the tests herein.

As an alternate to the exfiltration test, a low pressure air test may be conducted after backfilling and before replacing pavement. The equipment shall be provided and tests shall be conducted by the contractor in the presence of the design engineer and a representative of the Building Commission.

The contractor may desire to make an air test prior to backfill for his/her own purposes, but "Acceptance Test" shall be conducted after backfill.

After each manhole-to-manhole section of line has been backfilled and cleaned, the ends shall be plugged with pneumatic plugs. These plugs shall be designed such that they will hold against line test pressure without requiring blocking or bracing. All pneumatic plugs shall pass a qualifying test in the presence of the Engineer before actual line testing as follows: One (1) length of pipe shall be laid on the ground and sealed at both ends with the pneumatic plugs being tested. Air shall be introduced into the pipe until the pipe pressure reaches 15 p.s.i.g. The pneumatic plugs shall hold against this pressure without bracing and movement of the plugs.

Air for inflation of the triple connection pneumatic plug shall be supplied through a factory-equipped control panel. There shall be three (3) hose connections from the control panel to the triple connection pneumatic plug. One (1) hose shall be used only for inflation of the pneumatic plug. The second (2nd) hose shall be used for continuously reading the air pressure rise in the sealed line. The third (3rd) hose shall be used only for introducing low pressure air into the sealed line.

There shall be a three and one-half (3½) inch diameter, 0-30 p.s.i.g. gauge mounted on the control panel for reading the internal pressure of the line being tested. Calibrations from the 0-10 p.s.i.g. range shall be in tenths of pounds (not ounces) and this 0-10 portion shall cover ninety percent (90%) of the complete dial range.

Low pressure air shall be introduced into the sealed line until the internal air pressure reaches four point zero (4.0) p.s.i.g. greater than the average back pressure of any ground water pressures that may be over the pipe. At least two (2) minutes shall be allowed for the air pressure to stabilize. After the stabilization period, the third (3rd) hose shall be quickly disconnected from the control panel.

The portion of line being tested shall be accepted if the portion under test does not lose air at a rate greater than 0.003 cfm per square foot of internal pipe surface when tested at an average pressure of three point zero (3.0) p.s.i.g. greater than any back pressure exerted by ground water that may be over the pipe at the time of the test.

The above requirement shall be accomplished by performing the test as follows: The time required in minutes for the pressure to decrease from three point five (3.5) to two point five (2.5) p.s.i.g. (greater than the average back pressure of any ground water that may be over the pipe) shall not be less than the time shown for the given diameters in the following table:

	Pipe Size	Minimum Air Loss Time 100 Ft. of Pipe
	Inches	Minutes	Seconds
	6 8 10 12	2 3 4 5	50 47 43 40

conforming to the deflection test specified shall be removed and replaced at the contractor's expense and retested. This test is only required for flexible pipe.

Section 510.160 Disposal of Excess Excavated Material.

[R.O. 2011 §510.160; Ord. No. 028-87 §14-19.3, 5-6-1987]

Except as otherwise permitted, all excess excavated materials shall be disposed of by the contractor.

The disposal of waste and excess excavated materials, including hauling, handling, leveling, and surfacing, shall be a subsidiary obligation of the developer/contractor.

Section 510.170 Alignment and Grade.

[R.O. 2011 §510.170; Ord. No. 028-87 §4-19.3, 5-6-1987]

Unless otherwise shown on the drawings, all gravity sewer pipe shall be laid straight between changes in alignment and at a uniform grade between changes in grade. All lines shall be laid so that each section between manholes will lamp.

The contractor shall establish construction line and grade by the proper use of laser equipment.

Section 510.180 Laser Equipment.

[R.O. 2011 §510.180; Ord. No. 028-87 §4-19.3, 5-6-1987]

The laser equipment used shall be specifically designed for use in the construction of sewers to line and grade. The laser shall be rigidly mounted with two point suspension, to its support platforms. The laser aligning method selected must be shown to have worked satisfactorily on at least three (3) similar projects within the last two (2) years. The laser shall be operated by manufacturer trained competent persons. Proof and demonstration of such training shall be required. The laser equipment used shall be equal to that manufactured by Laiser Alignment, Inc., Spectrophysics, Construction Laser Systems, AGL.

Section 510.190 Explosives — Blasting Permit Required.

[R.O. 2011 §510.190; Ord. No. 028-87 §4-19.3, 5-6-1987]

The contractor shall comply with all laws, ordinances, applicable safety code requirements, and regulations relative to the handling, storage, and use of explosives and the protection of life and property. He/she shall be responsible for all damage caused by his/her blasting operations. A Blasting Permit from the Building Commission is required. A damage liability bond will be necessary for the amount listed on the blasting permit application.

Section 510.200 Safety.

[R.O. 2011 §510.200; Ord. No. 028-87 §4-19.3, 5-6-1987]

Barricades. To protect persons from injury and to avoid property damage, adequate barricades, construction signs, torches, red lanterns and guards as required shall be placed and maintained by the contractor at his/her expense during the progress of the construction work and until it is safe for traffic to use the roads and streets. All material piles, equipment and pipe which may serve as obstructions to traffic shall be enclosed by fences or barricades and shall be protected by proper lights when the visibility is poor. The rules and regulations of the City of Byrnes Mill respecting safety provisions shall be observed.

Temporary Support Of Underground Structures. Temporary support, adequate protection and maintenance of all underground and surface structures, drains, sewers, and other obstructions encountered in the progress of the work shall be furnished by the contractor at his/her expense and under the direction of the design engineer. The structures which may have been disturbed shall be restored upon the completion of the work.

Fences, Poles, Etc. Fences, poles, and all other property and surface structures shall be protected during construction operations unless their removal for purposes of construction is authorized by the Engineer. Any fences, poles, or other man-made surface improvements which are moved or disturbed by the contractor shall be restored to the original condition, after construction is completed, at the contractor's expense.

Trees Or Shrubbery. Any trees or shrubbery which are located within a twenty (20) foot wide strip of land, ten (10) feet on either side of the sewer main, may be removed by the contractor. Care should be taken to leave in place as many trees as possible. Responsibility for any damage or claims for damage caused by the construction operations inside or outside of the twenty (20) foot wide construction strip shall be assumed by the contractor. Settlement of any damage or claims for damage shall be made by the contractor as soon as possible and in a manner satisfactory to the Building Commission. Any grass area disturbed by the contractor shall be sodded.

Excavation. The contractor shall proceed with caution in the excavation and preparation of the trench so that the exact location of underground structures, both known and unknown, may be determined, and he/she shall be held responsible for the repair of such structures when broken or otherwise damaged by him/her.

Section 510.210 Final Grading and Seeding.

[R.O. 2011 §510.210; Ord. No. 028-87 §4-19.3, 5-6-1987]

After placement of backfill and embankments are completed, all areas on the site of the work that have been disturbed shall be brought to the grade at the specified elevations, slopes, and contours. Slopes shall be trimmed and dressed by hand and other surfaces so graded that effective drainage is secured. Grading and surfacing shall be completed to the satisfaction of the design engineer.

Section 510.220 Construction Near Existing Utilities.

[R.O. 2011 §510.220; Ord. No. 028-87 §4-19.3, 5-6-1987]

The contractor shall maintain in operating condition, all active utilities, sewers, gutters, and other drains encountered in the new installation, and repair to the satisfaction of the owner any surface or subsurface improvement damaged during the course of the work, unless such improvement is shown to be abandoned or removed. The contractor shall be responsible for notifying all utilities or other interested parties when utility lines are liable to injury or damage through performance of the work, and shall make necessary arrangements with such owner or owners relative to the removal and replacement or protection of such property or utilities.

The contractor shall satisfactorily shore, support, and protect any and all structures and all pipes, sewers, drains, conduits, and other facilities belonging to the owner, and be responsible for any damage resulting thereto. The contractor shall not be entitled to any damages or extra pay on account of any postponements, interference or delay caused by any such structures and facilities being on the line of the work, whether they are shown on the plans or not.

Section 510.230 Interruption To Utilities and Traffic.

[R.O. 2011 §510.230; Ord. No. 028-87 §4-19.3, 5-6-1987]

The contractor shall take all reasonable precautions against damage to existing utilities. However, in the event of a break in an existing watermain, sewer, or underground cable, he/she shall immediately notify a responsible official from the organization operating the utility interrupted. The contractor shall lend all possible assistance in restoring service and shall assume all costs, charges, or claims connected with the interruption and repair of such services.

The contractor shall carry on the work in a manner which will cause a minimum of interruption to traffic, and may close through travel only where and when approved by the Building Commission. Where traffic must cross open trenches, the contractor shall provide suitable bridges at street intersections. and driveways. The contractor shall furnish and post, where directed by the Building Commission, suitable signs indicating that a street is closed and necessary detour signs for the proper maintenance of traffic. Prior to closing any streets, the contractor will notify the City authorities.

All open trenches and other excavations shall be provided with suitable barriers, signs, and lights to the extent that adequate protection is provided to the public. Obstructions, such as material piles and equipment, shall be provided with similar warning signs and lights. All barricades and obstructions shall be illuminated by means of warning lights at night. All lights used for this purpose shall be kept burning from sunset to sunrise. Materials stored upon or alongside public streets and highways shall be so conducted, as to cause the minimum obstruction and inconvenience to the traveling public. All barricades and light expense will be paid by the contractor.

Section 510.240 Unsuitable Backfill Material.

[R.O. 2011 §510.240; Ord. No. 028-87 §4-19.3, 5-6-1987]

Where there is a deficiency of suitable backfill material due to a rejection of part or all of the excavated material as unsatisfactory for backfill purposes, the contractor shall furnish satisfactory backfill material wasted from trench excavation in other locations or from other sources furnished by the contractor.

Section 510.250 Construction in Easements.

[R.O. 2011 §510.250; Ord. No. 028-87 §4-19.3, 5-6-1987]

In easements across private property, the contractor shall confine all operations in the easement area. Trees, fences, shrubbery or other type of surface improvements located in easements will require protection during construction. The provisions of this specification shall apply to all easement areas as well as to public rights-of-way. Precautions shall be taken by adequate sheeting or other approved methods to prevent any cave-in or subsidence beyond the easement limits or damage to improvements within the easements. In general, the easement area is intended to provide reasonable access and working area for efficient operation by the contractor. Where easement space for efficient operation is not provided, the contractor shall be responsible for organizing his/her operations to perform the restrictions shown on the plans.

Section 510.260 Pavement Removal and Replacement.

[R.O. 2011 §510.260; Ord. No. 028-87 §4-19.3, 5-6-1987]

Where surfaced streets, walks, drives, or parking areas are cut, removed, or damaged in the prosecution of the work, the contractor shall replace all pavements or other surfacings so removed or damaged to their original, or better state and condition.

After trench backfill with granular material, the contractor shall maintain the surface at pavement grade until the permanent pavement is replaced.

Pavements constructed of asphalt or concrete shall be removed in a careful manner and so that not less than six (6) inches in width at any point is left between the cut edge of the pavement and the top edge of the trench. All asphalt or black-top pavements, removed or damaged, shall be replaced with two (2) inches of asphalt concrete. Asphalt concrete shall comply with minimum requirements for Type "C" mixes as specified under Section 403 of the Missouri State Highway 1981 Standard Specifications.

All concrete pavements, removed or damaged, shall be replaced with an eight (8) inch thick concrete slab of Class A concrete reinforced with zero point twenty-five percent (0.25%) steel.

Gravel surfaced streets shall require no repaving other than the gravel surface of trench backfill or a twelve (12) inch surface layer of better material if such is normally used by the authority maintaining the road. A trench in a graveled street will be considered as having been repaved when the graveled surface has become stable and is at proper grade.

Section 510.270 Location of Sewer Mains With Respect To Existing Water Mains.

[R.O. 2011 §510.270; Ord. No. 028-87 §4-19.3, 5-6-1987]

Horizontal Separation. All sewer lines shall be laid at least ten (10) feet horizontally from existing water lines. Should conditions prevail preventing a lateral separation of ten (10) feet, a vertical separation of at least eighteen (18) inches between the top of the sewer and the bottom of the water main shall be obtained. If it is impossible to obtain proper horizontal and vertical separation as stipulated, the sewer main shall be constructed of cast iron pipe and water main encased in concrete if the water main is found to be of a material other than cast iron pipe.

Vertical Separation. Whenever a sewer main crosses under an existing water main, a vertical separation of at least eighteen (18) inches between the top of the sewer and the bottom of the water main must be maintained. This vertical separation shall be maintained within a lateral distance of ten (10) feet from the sewer or from the water main. Whenever a sewer main crosses under a water main and the vertical distance between the top of sewer main and the bottom of the water main is less than eighteen (18) inches or when a sewer main crosses over an existing water main, the sewer shall be laid with cast iron pipe and the existing water main encased in concrete for a distance of ten (10) feet from the crossing. Where these conditions cannot be met, the Division of Health shall be consulted as to the precautions to be taken to protect the public water supply.

Sewer Manholes. No water pipe shall pass through, or come into contact with, any part of a sewer or sewer manhole.

Special Conditions. When it is impossible to obtain proper horizontal and vertical separation as stipulated above, the sewer shall be constructed equal to water pipe, and shall be pressure tested to assure water-tightness prior to backfilling. This shall be considered incidental to the sewer construction and no additional payment shall be provided for installing and testing the water pressure class pipe.