[Ord. No. 1711 §§1 — 3, 9-13-2004]
A.
Sanitary
sewer construction shall consist of furnishing all labor, materials
and equipment for the complete installation of sewers and appurtenances
in accordance with the approved design plans and specifications and
all regulatory requirements of the City of St. Robert.
B.
When
reference is made to a Standard Specification (ASTM, AWWA), the specification
referred to shall be understood to mean the latest revision of said
specification.
C.
Development
of all sanitary sewer infrastructure will be guided by strict compliance
of the approved design plans and specifications. Until reviewed and
approved by the City Engineer or Director of Public Works, no changes
or modifications shall be authorized and no deviations permitted from
the originally approved design plans and project specifications. Change
orders and design modifications will be submitted by the developer's
project engineer only and no other person.
[Ord. No. 1711 §§1 — 3, 9-13-2004]
A.
Installation. All work shall be in accordance with ASTM
D-2321 — Underground Installation of Flexible Thermoplastic
Sewer Pipe.
2.
Joint deflection shall not exceed the maximum allowable deflection
per joint according to ASTM C-425, ASTM C-594 and AWWA C-600. Only
one (1) correction for alignment and/or grade shall be made between
adjacent manholes.
3.
Except where pipe sections are being encased in concrete, no pipe
is to be supported by blocks.
4.
All transition in sewer main line and grade must be within a manhole.
5.
Install pipe of size, material, strength class and joint type with
embedment as shown on the approved plans.
6.
Pipes installed on grades in excess of twenty percent (20%) shall
be anchored securely with concrete anchors spaced as follows:
|
Grade
|
Maximum Anchor Spacing
| |
|---|---|---|
|
20% — 35%
|
36 feet
| |
|
35% — 50%
|
24 feet
| |
|
Greater than 50%
|
16 feet
|
7.
Insofar as possible, commence laying at downstream end of line and
install pipe with spigot or tongue end downstream.
8.
Clean interior of all pipe, fittings and joints prior to installation.
Exclude entrance of foreign matter during discontinuance of installation.
Close open ends of pipe with snug fitting closures. Do not let water
fill trench. Include provisions to prevent flotation should water
control measures prove inadequate. Remove water, sand, mud and other
undesirable materials from trench before removal of end cap. Install
pipe only when weather and trench conditions are suitable. Do not
lay in water. Brace or anchor pipe as required to prevent displacement
after establishing final position.
9.
The sewer trench shall be carried to a point not less than four (4)
inches below bottom of pipe bell. Crushed stone bedding, compacted
to full width of trench, shall then be placed and compacted to bottom
of pipe with proper allowance for bell joints. After each length of
pipe being laid has been shoved "home" and placed in proper alignment,
it shall be securely anchored and held in position by crushed stone
deposited simultaneously on each side of the pipe. This crushed stone
backfill shall extend to a point not less than six (6) inches above
the top of the pipe bell. If unstable conditions are encountered and
it is determined by the engineer that the bedding specified will not
provide suitable support for the pipe, additional excavation to the
limits determined by the engineer will be required. This additional
excavation shall be backfilled with crushed stone material approved
by the engineer.
B.
Jointing. Locate joints to provide for differential movements
at changes in type of pipe embedment, concrete collars and structures.
Support pipe from wall of manhole to first (1st) joint in normal sewer
trench with concrete cradle structurally continuous with base slab
or footing.
1.
Clean and lubricate all joint and gasket surfaces with lubricant
recommended by pipe manufacturer.
2.
Utilize methods and equipment capable of fully homing or making up
joints without damage.
3.
Check joint opening and deflection for specification limits.
4.
Examine each piece of pipe prior to installation for soundness and
specification compliance.
C.
Cutting. Cut in neat workmanlike manner without damage to
pipe. Observe specifications regarding joint locations. Smooth cut
by power grinding to remove burrs and sharp edges. Repair lining as
required and approved.
D.
Plugs. Provide and install plugs as manufactured by pipe
supplier or as fabricated by contractor if approved.
1.
Plugs shall be watertight against heads up to twenty (20) feet of
water. Secure plugs in place in a manner to facilitate removal when
required to connect pipe.
2.
Plugs shall be installed as specified or where shown on plans. Also
the open end of the sewer shall be plugged at the end of the workday
with a suitable mechanical plug to prevent entry of foreign material
until work is resumed.
E.
Connections To Existing Pipelines And Structures.
1.
Connect pipe to existing structures and pipelines where indicated.
Observe pertinent articles of specifications pertaining to joint locations.
2.
Pipe-to-Manhole Connector.
[Ord. No. 2724 §§1 — 3, 10-20-2014]
a.
A flexible pipe-to-manhole connector shall be used for sanitary
and drain pipe penetrations into existing and precast concrete manholes
and structures. The connector shall be the Inserta-LOK connector as
manufactured by A-LOK Products, Inc., Tullytown, PA or approved equal.
b.
The design of the seal shall provide a flexible, positive watertight
connection between the pipe and concrete wastewater structures. The
connector shall assure that a seal is made between the connector and
the structure wall, and between the connector and the pipe. The seal
between the connector and the structure wall will be made by pure
compression of the resilient material against the wall of the structure.
The seal between the connector and the pipe will be made by pure compression
of the resilient material against the outside diameter of the pipe.
The connector shall be the only component to affect the seal between
the pipe and structure.
c.
The connector shall be extruded and vulcanized from materials
whose physical/chemical properties meet or exceed the physical/chemical
resistant properties outlined in ASTM C-923.
d.
The connector shall be the size specifically designed for the
pipe material being used and shall be installed in accordance with
the recommendations of the manufacturer.
3.
Manholes to be built on an existing sewer shall be constructed in
such a manner as will not disturb services of existing sewer. The
manhole base, walls and invert shall be completed before the top half
of the sewer pipe is cut or broken away. Rough edges of the pipe thus
exposed shall be covered with expansive grout in such a manner as
to produce a smooth and acceptable finish. Any portion of the existing
sewer damaged by the contractor shall be repaired at no expense to
the City.
4.
Connections between different pipe materials shall be made using
proprietary transition coupling unless otherwise specified on the
plans.
F.
Service Lines And Connections.
1.
Wyes and saddles for service lines shall be installed at a forty-five
degree (45°) angle measured from the horizontal centerline of
the pipe for pipe sizes eight (8) inches through fifteen (15) inches
in diameter. Service lines shall not be installed in pipe sizes eighteen
(18) inches in diameter or larger unless approved by the City Engineer.
Wyes shall be eight (8) inches by four (4) inches with DVW branch
and shall be installed on new sewer mains as the mains are installed.
2.
Service lines under streets shall be installed by the developer
extending from the main to the limits of the street right-of-way and
shall be installed prior to construction of the street at a slope
not less than one (1) foot per one hundred (100) feet [one percent
(1.0%)]. Service lines for each building unit shall be connected to
the mains by means of a wye or tee and shall extend at least to the
street right-of-way but never less than ten (10) feet from the sewer
main and shall have warning tape labeled ("Buried Sewer Line Below")
eighteen (18) inches below final grade of all sewer lines. The contractor
shall also install a tracer wire mounted on top of the pipe that shall
be #12 (minimum) green in color Copperhead clad steel wire housed
in a polyethylene coating, as manufactured by Copperhead Industries.
Splicing shall be with 3M DBY/DBR Direct Bury Splice Kit or approved
equal. Individual service lines shall not connect directly into manholes
unless approved by the City Engineer. Service lines shall be adequately
plugged to prevent foreign matter from entering the pipe during construction.
All service lines shall be constructed bell to spigot or shall have
a solid glued sleeve.
[Ord. No. 2724 §§1 — 3, 10-20-2014]
3.
Saddles are only to be used to connect to existing sanitary sewers.
The saddle shall be installed over a hole sized to fit the saddle
opening (four (4) inch minimum). Cut shall be made with non-impact
rotary equipment.
4.
The service line shall terminate at a capped cleanout, and a two-way tee (double sanitary tee) is required. The cleanout location shall have a protective cover. The protective cover shall be model #2194-S as manufactured by Clay and Bailey Products with "sewer" or the letter "S" on the lid. The top of the cleanout must be set a minimum of three (3) inches below the bottom of the box lid and the tracer wire as described in Subsection F(2) above shall terminate in the protected cover with no less than eighteen (18) inches of extra wire inside the cover for locating purposes.
[Ord. No. 2724 §§1 — 3, 10-20-2014]
5.
The developer shall maintain an accurate record for the production
of the as-built drawings of the location, size and direction of each
tee and wye and location, size and length of each building service
line. Locations will be referenced to the pipe line stationing as
shown on the plans or the distance from the first (1st) downstream
manhole.
[Ord. No. 1711 §§1 — 3, 9-13-2004]
A.
Scope. This Section governs the furnishing of all labor,
equipment, tools and materials and the performance of all work incidental
to the construction of manholes, drop manholes and special sewer structures
complete with covers, steps, fittings and appurtenances as required
in accordance with the approved plans.
B.
General. As used herein, special structures refers to manholes
on large sewers, special junction structures, metering stations, siphons
and similar structures constructed on the pipeline. Manholes and special
structures may be constructed of precast concrete sections, cast-in-place
concrete on existing mains or where space does not permit a precast
manhole.
C.
Construction.
1.
Manholes and special structures shall be constructed at locations
indicated and in accordance with details as shown on the plans.
2.
Precast wall and reducing cone sections. Handle
with care to avoid damage to joint ends of each section. Damaged sections
may be subject to rejection at the discretion of the engineer. When
using O-ring joints, care shall be exercised in placing the O-ring
on the spigot end and lowering the bell section on to the spigot end
so that a watertight seal is obtained.
3.
When using bitumastic joints both spigot and bell ends shall be primed
with solvent material compatible to the adhesive in the mastic. Approved
bitumastic material shall completely fill the joints so that a minimum
of one-fourth (¼) inch bead of material is visible after jointing,
to be smoothed off after completion of the jointing operation.
4.
When a flexible preformed butyl rubber or bituminous polymer compounded
with modifiers is used to seal jointed sections of manholes, the extrusion
of sealant from the joint is not required. The vertical spacing between
manhole sections shall not exceed one-fourth (¼) inch. Preformed
joint sealers remain flexible at temperatures as low as zero degrees
Fahrenheit (0°F).
5.
All bitumastic materials or preformed flexible joint sealants shall
not be applied to wet or damp surfaces.
6.
Cast-in-place. Consolidate concrete with mechanical
vibrators to eliminate entrapped air voids and rock pockets. Forms
shall be supported in such a manner as to prevent any movement of
the forms while concrete is being cured. Any movement of the forms
may be cause for rejection.
7.
Invert channels. Alignment of the invert channels
shall be as shown on the approved plans. When no specific details
and dimensions are given, changes in flow direction shall be smooth,
uniform and made with the longest radius possible. The cross section
shape of invert channels shall match the lower halves of the entering
and exiting pipes. The surfaces of the channels shall be steel-troweled
to produce a dense, smooth surface. When filling openings around pipes
through manhole walls, mortar and/or masonry units shall be placed
so that the resulting joints are watertight. Mortar used in the joint
closure shall not interfere with the invert channel.
D.
Curing. Cast-in-place concrete shall be adequately protected
from freezing and loss of moisture for the first twenty-four (24)
hours. The curing methods and materials to be used shall be approved
by the engineer.
E.
Manhole Rings. All rings for manhole covers shall be set
to match the existing surfaces, except in floodplains where the plans
indicate that the ring is to be set at an elevation higher than existing
ground. Each ring shall be set on a full mortar bed of bitumastic
material, if approved by the engineer. If masonry units are used to
adjust rings to grade, the masonry work shall conform to Subparagraph
(C)(7) of these specifications.
F.
Waterproofing. Two (2) coats of an asphalt or coal-tar pitch
waterproof coating shall be applied to the exterior of all structures
from base to manhole ring. The coating shall be applied in sufficient
quantity so that no bare or thin spots show. The coating shall be
applied in sufficient time to permit proper curing prior to backfilling
the excavation. Proper methods and materials shall be used during
backfilling to prevent damage to the coating. Any damage to the coating
that does occur shall be immediately repaired.
[Ord. No. 1711 §§1 — 3, 9-13-2004]
A.
Unless
otherwise specified, all sewer trenches and excavation around structures
shall be backfilled to the original surface of the ground with earth,
earth and rock or other acceptable material. When earth and rock is
used, it shall be placed and thoroughly consolidated with sufficient
earth to completely fill all voids between the rocks. The developer
shall so sort and stockpile the excavated material so that the proper
material is available for backfill.
1.
The backfill material shall be compacted to a minimum of eighty percent
(80.0%) of optimum density as determined by the Standard Proctor Test
or shall be compacted to a density equivalent to the density of the
immediate adjoining soil. The top six (6) inches of backfill in street
right-of-way shall be compacted to a minimum density of ninety-five
percent (95.0%) of optimum density as determined by the Standard Proctor
Test. Backfill material shall be placed and compacted only when its
moisture content is within two percent (2.0%) of optimum moisture
content as determined by Standard Proctor Test.
2.
The combination of the thickness of the layer, the method of compaction
and the type of compaction equipment shall be at the discretion of
the contractor subject to obtaining the densities as specified above.
3.
The quality of the compactions shall be subject to compaction tests
when deemed necessary by the City Engineer. It shall be the developer's
responsibility to make necessary excavation in order to accommodate
compaction tests at locations specified by the City Engineer. The
compaction tests will be performed at no cost to the City. If the
quality of the compaction does not meet the above requirements, the
material will be removed and replaced to meet the above requirement
at the expense of the developer.
4.
Commercial sand backfill shall not be used.
5.
Backfill material shall be carefully placed to avoid damage or displacement
of sewer or structures.
6.
Backfill shall not be placed when material contains frost, is frozen
or a blanket of snow prevents proper compaction. Backfill shall not
contain waste material, trees organic material, rubbish, etc.
B.
Backfill Of Pipe Trenches.
1.
The area below a plane six (6) inches above the top of pipe bell
shall be backfilled in accordance with the specifications for "Pipe
Bedding".
2.
Backfill above a plane six (6) inches above the top of pipe bell
shall be made with suitable earth, earth and rock or other acceptable
material except that the area below a plane one (1) foot above the
pipe bell shall not contain any excavated rock. When earth and rock
is used, the maximum dimension of the rock shall not exceed twelve
(12) inches.
C.
Backfill Around Structure.
1.
No backfill shall be placed over or around any structure until the
concrete or mortar therein has attained a minimum strength two thousand
(2,000) psi and can sufficiently support the loads imposed by the
backfill without damage.
2.
The developer shall use utmost care to avoid any wedging action between
the side of the excavation and the structure that would cause any
movement of the structure. Any damage caused by premature backfill
or by the use of equipment on or near a structure will be the responsibility
of the developer.
3.
Backfill shall be placed and compacted on all sides of the structure
simultaneously and operations shall be so conducted that the backfill
is always at approximately the same elevation on all sides of the
structure.
4.
No excavated rock larger than four (4) inches maximum dimension shall
be placed within one (1) foot of the exterior surface of any structure.
[Ord. No. 1711 §§1 — 3, 9-13-2004]
A.
Visual Inspection.
1.
Contractor shall clean pipe of excess mortar, joint sealant and other
dirt and debris prior to inspection.
2.
Sewer will be inspected by flashing a light between manholes and/or
by physical passage where space permits. Determine from illumination
and/or physical inspection the presence of any misaligned, displaced
or broken pipe and the presence of visible infiltration or other defects.
3.
Correct defects as required prior to conducting leakage tests.
B.
Exfiltration Leakage Test. To be performed on the full length
of all lines prior to acceptance.
1.
Test all sewer pipe over eighteen (18) inches I.D. after either the
completed backfill or partial backfill sufficient to stabilize the
position of the pipe in both alignment and grade is accomplished.
The developer may select sections of the project for testing at any
time by notifying the Public Works Department twenty-four (24) hours
in advance.
2.
Perform at depths of water as measured above centerline of pipe of
not less than two (2) feet or more then ten (10) feet (consideration
shall be given for water table above said centerline).
3.
Maintain test as necessary to locate all leaks but not less than
two (2) hours.
4.
Repeat as necessary after repair of leaks and defects until leakage,
as measured, does not exceed fifteen hundredths (0.15) gallons per
inch of internal diameter per hour per one hundred (100) feet of pipe
length (200 gal/inch of I.D./day/mile).
5.
Protect manholes and other structures by means of bulkheads to prevent
bursting pressures from being applied inside the structure.
6.
Dewater pipe upon completion of testing.
C.
Air Leakage Test. To be performed on the full length of
all lines prior to acceptance.
1.
The pipe plug for introducing air to the sewer line shall be equipped
with two (2) taps. One (1) tap will be used to introduce air into
the line being tested, through suitable valves and fittings, so that
the input air may be regulated. The second (2nd) tap will be fitted
with valves and fittings to accept a pressure test gauge indicating
internal pressure in the sewer pipe. An additional valve and fitting
will be incorporated on the tap used to check internal pressure so
that a second (2nd) test gauge may be attached to the internal pressure
tap. The pressure test gauge will also be used to indicate loss of
air pressure due to leaks in the sewer line.
2.
The pressure test gauge shall meet the following minimum specifications:
|
Size (diameter)
|
4½ inches
| |
|
Pressure range
|
0 — 15 p.s.i.
| |
|
Figure intervals
|
1 p.s.i. increments
| |
|
Minor subdivisions
|
0.05 p.s.i.
| |
|
Pressure tube
|
Bourdon tube or diaphragm ±0.25% of maximum scale reading.
| |
|
Dial
|
White coated aluminum with black lettering, 270 degree arc and
mirror edge.
| |
|
Pipe connection
|
Low male ½" N.P.T. Calibration data will be supplied
with all pressure test gauges. Certification of pressure test gauge
will be required from the gauge manufacturer. This certification and
calibration data will be available to the engineer whenever air tests
are performed.
|
3.
Test each reach of sewer pipe between manholes after completion of
the installation of pipe and appurtenances and the backfill of sewer
trench.
4.
Plug ends of line and cap or plug all connections to withstand internal
pressure. One (1) of the plugs provided must have two (2) taps for
connecting equipment. After connecting air control equipment to the
air hose, monitor air pressure so that internal pressure does not
exceed five (5.0) psig. After reaching four (4.0) psig, throttle the
air supply to maintain between four (4.0) and three and one-half (3.5)
psig for at least two (2) minutes in order to allow equilibrium between
air temperature and pipe walls. During this time, check all plugs
to detect any leakage. If plugs are found to leak, bleed off air,
tighten plugs and again begin supplying air. After temperature has
stabilized, the pressure is allowed to decrease to three and one-half
(3.5) psig. At three and one-half (3.5) psig, begin timing to determine
the time required for pressure to drop to two and one-half (2.5) psig.
If the time, in seconds, for the air pressure to decrease from three
and one-half (3.5) psig to two and one-half (2.5) psig is greater
than that shown on the table below, the pipe shall be presumed free
of defects.
|
Pipe Size
|
Required Time per 100 LF
|
Maximum Required Time
| |
|---|---|---|---|
|
8 inches
|
70 seconds
|
227 seconds
| |
|
10 inches
|
110 seconds
|
283 seconds
| |
|
12 inches
|
158 seconds
|
340 seconds
| |
|
15 inches
|
248 seconds
|
425 seconds
| |
|
18 inches
|
356 seconds
|
510 seconds
| |
|
21 inches
|
485 seconds
|
595 seconds
| |
|
24 inches
|
634 seconds
|
680 seconds
| |
|
27 inches
|
765 seconds
|
765 seconds
| |
|
30 inches
|
851 seconds
|
851 seconds
| |
|
33 inches
|
935 seconds
|
935 seconds
|
5.
If air test fails to meet above requirements, repeat test as necessary
after all leaks and defects have been repaired. Prior to acceptance
all constructed sewer lines shall satisfactorily pass the low pressure
air test.
6.
In areas where ground water is known to exist, install a one-half
(½) inch diameter capped pipe nipple, approximately ten (10)
inches long, through manhole wall on top of one (1) of the sewer lines
entering the manhole. This shall be done at the time the sewer line
is installed. Immediately prior to the performance of the line acceptance
test, ground water level shall be determined by removing pipe cap,
blowing air through pipe nipple into the ground so as to clear it
and then connecting a clear plastic tube to pipe nipple. The hose
shall be held vertically and a measurement of height in feet of water
shall be taken after the water stops rising in this plastic tube.
The height in feet shall be divided by two and three-tenths (2.3)
to establish the pounds of pressure that will be added to all readings.
[Ord. No. 1711 §§1 — 3, 9-13-2004]
A.
A hydrostatic
pressure and leakage test shall be performed in conformance with AWWA
C-600 procedures as modified herein. Test shall apply to all pressure
sewers and shall be performed after backfilling.
B.
Test
separately in segments between sectionalizing valves, between a sectionalizing
valve and a test plug or between test plugs. Select test segments
such that adjustable seated valves are isolated for individual checking.
Developer shall furnish and install test plugs including all anchors,
braces and other devices to withstand hydrostatic pressure on plugs.
The developer shall be responsible for any damage to public or private
property caused by failure of plugs. Limit full rate of line to available
venting capacity.
C.
Pressure Test. Conduct at one and one-half (1.5) times maximum
operating pressure determined by following formula:
|
|
P pt = 0.650 (OP-GE) in which
| |||
|---|---|---|---|---|
|
|
P pt
|
=
|
test pressure in psi at gauge elevation.
| |
|
|
OP
|
=
|
operating pressure in feet as indicated for highest elevation
of the hydraulic gradient on each section of the line.
| |
|
|
GE
|
=
|
elevation in feet at centerline of gauge. Perform satisfactorily
prior to determining leakage.
| |
D.
Leakage Test. Conduct at maximum operating pressure determined
by following formula:
|
|
P lt = 0.433 (OP-GE) in which
| |||
|---|---|---|---|---|
|
|
P lt
|
=
|
test pressure in psi at gauge elevation.
| |
|
|
OP and GE
|
=
|
as in previous subparagraph.
| |
E.
All
joints shall be watertight and free from leaks.
F.
Deflection Test. Gravity pipeline #f flexible materials
shall also be tested by pulling a mandrel. The test shall be conducted
not less than one (1) month after backfill has been properly installed.
The maximum allowable deflection shall not exceed five percent (5%)
of the pipe's internal diameter. Mandrel testing shall be performed
on a minimum of twenty-five percent (25%) of the pipeline. The sections
tested will be determined by the City.
[Ord. No. 1711 §§1 — 3, 9-13-2004]
A.
All
manholes shall be vacuum tested by the contractor at his expense.
Appropriate equipment and manpower will be furnished by the developer
for this purpose. When vacuum testing manholes, the following criteria
are to be used:
1.
This method is applicable to precast manholes only.
2.
All lift holes shall be plugged with an approved non-shrink grout.
3.
Manholes are to be tested after assembly and before backfilling.
No standing water shall be allowed in the manhole excavation that
may affect the accuracy of the test.
4.
All pipes and other openings into the manhole shall be plugged and
securely braced to prevent displacement of the plugs while the vacuum
is drawn.
5.
Installation and operation of vacuum equipment shall be in accordance
with equipment specifications and instructions provided by the manufacturer.
6.
The test head may be placed in the cone section of the manhole. The
frame-cone joint will be visually inspected by the engineer.
7.
A vacuum of ten (10) inches of mercury shall be drawn and the vacuum
pump shut off. The time for the vacuum to drop to nine (9) inches
of mercury shall be recorded.
8.
Acceptance for four (4) foot diameter manholes shall be defined as
when the time to drop to nine (9) inches of mercury meets or exceeds
the following:
|
Manhole Depth
|
Diameter
|
Time to Drop 1 inch of HG
| |
|---|---|---|---|
|
10 feet or less
|
4 feet
|
60 seconds
| |
|
10 feet to 15 feet
|
4 feet
|
75 seconds
| |
|
15 feet to 20 feet
|
4 feet
|
90 seconds
|
9.
For manholes five (5) foot in diameter, add an additional fifteen
(15) seconds and for manholes six (6) foot in diameter, add an additional
thirty (30) seconds to the time requirements for four (4) foot diameter
manholes. If the manhole fails to test, necessary repairs shall be
made with a non-shrink grout while the vacuum is still being drawn.
Retesting shall proceed until a satisfactory test is obtained.
