[R.O. 2011 §510.110; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
C. 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.
[R.O. 2011 §510.120; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
C. 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.
D. 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.
E. 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.
[R.O. 2011 §510.130; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
C. 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.
[R.O. 2011 §510.140; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. Manholes shall be pre-cast concrete. Manhole frames and covers shall be of cast iron as shown on the drawings in Article
IV.
B. Pre-cast
manholes may be constructed with a pre-cast base section or a monolithic
base structure.
C. 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.
D. 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.
E. 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.
F. 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.
G. 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.
H. Backfilling
shall be done carefully with selected earth fill, free from rocks
and debris, without damage to the manhole.
[R.O. 2011 §510.150; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
C. No ground
water in an amount greater than that allowed and specified herein
for the exfiltration test shall be permitted.
D. 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.
E. The contractor
shall cooperate fully with the design engineer and the Building Commission
for the inspection and testing of the completed work.
F. 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.
G. 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.
H. 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.
I. 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.
J. 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.
K. 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.
L. 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.
M. 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.
N. 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.
|
[R.O. 2011 §510.160; Ord. No. 028-87 §14-19.3, 5-6-1987]
A. Except
as otherwise permitted, all excess excavated materials shall be disposed
of by the contractor.
B. The disposal
of waste and excess excavated materials, including hauling, handling,
leveling, and surfacing, shall be a subsidiary obligation of the developer/contractor.
[R.O. 2011 §510.170; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. The contractor
shall establish construction line and grade by the proper use of 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.
[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.
[R.O. 2011 §510.200; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
C. 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.
D. 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.
E. 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.
[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.
[R.O. 2011 §510.220; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
[R.O. 2011 §510.230; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
C. 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.
[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.
[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.
[R.O. 2011 §510.260; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. After
trench backfill with granular material, the contractor shall maintain
the surface at pavement grade until the permanent pavement is replaced.
C. 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.
D. 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.
E. 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.
[R.O. 2011 §510.270; Ord. No. 028-87 §4-19.3, 5-6-1987]
A. 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.
B. 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.
C. Sewer Manholes. No water pipe shall pass through, or come
into contact with, any part of a sewer or sewer manhole.
D. 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.