A written permit shall be obtained from the
Water and Sewer Board before any connection, opening, uncovering,
use, discharge, alteration or other disturbance of a Village sewer
or its tributaries and appurtenances is made. The permit shall be
displayed in a conspicuous place. Any work performed after issuance
of a permit shall be in conformity with its terms and conditions and
the provisions of this Part 1.
A. The property owner shall apply for a permit on a form
furnished by the Village Clerk and shall provide all information called
for on the form.
B. The permit application shall be accompanied by an
application fee established pursuant to a schedule adopted by resolution
of the Water and Sewer Board and by plans, specifications or other
information considered pertinent by the Water and Sewer Board.
C. All permit applications for service to establishments
producing industrial wastes shall be subject to Water and Sewer Board
approval after a public hearing held upon 10 days' notice to the general
public by publication in the Village's official newspaper.
A combined permit and inspection fee shall be
paid to the Village before a permit is issued. Fees shall be established
pursuant to a schedule adopted by resolution of the Water and Sewer
Board and may vary depending on whether the property served is residential,
commercial or industrial and on whether the permit is for an original
building sewer connection or some other purpose.
A. All costs and expenses incidental to the installation
and connection of the building sewer shall be borne by the property
owner.
B. Property owners who install their own building sewer
lateral connection shall indemnify said Village from any loss or damage
that may directly or indirectly be occasioned by said installation.
C. Any person working for fee (contractor) to make connections
to the Village sewer system must register with the Village.
D. All registered contractors must have on file with
the Village an owner's and contractor's protective liability insurance
policy in the name of the Village in the following amounts: bodily
injury, $500,000 each person and $1,000,000 each accident; and property
damage, $100,000.
The plumbing system of each building shall have
a separate and independent connection with the Village sewer wherever
possible. Where one building stands in the rear of another or is on
an interior lot and no connection to a sewer is available nor can
be made through an adjoining alley, court, yard or driveway, then
the building sewer from the building on the front of the lot may be
extended to the building on the rear of the lot. This may be considered
as one building sewer for permit and inspection fee purposes, but
for sewer service charge or rent purposes the number of connections
shall be based upon the number of units being serviced.
Existing building sewers may be used in conjunction
with new buildings only when they are found, upon information and
testing by the Water and Sewer Board, wholly at the expense of the
property owner, to meet all requirements of this Part 1 and any other
laws, rules, regulations and specifications which apply.
The repair, maintenance and cleaning of a building
sewer is the responsibility of the property owner. In the event of
the property owner's failure to repair, maintain or clean, the Village
may undertake the necessary work and charge all expenses to the property
owner. A minimum charge for such work shall be set by resolution of
the Water and Sewer Board.
Before any building with a building sewer is
demolished, the owner thereof shall conform to requirements established
by the Water and Sewer Board. The cutoff or plugging of the building
sewer shall be done only with the permission and under the supervision
of the Water and Sewer Board.
Improvements, enlargements and extensions by
private organizations to the Village sewer system shall be subject
to the approval of the Water and Sewer Board with regard to design,
construction and operation. Prior to the approval of the plans for
improvements, enlargements and extensions, said private organizations
shall deposit with the Village a sum sufficient to cover inspection
costs. This sum will be established pursuant to a schedule adopted
by resolution of the Water and Sewer Board, based on a percentage
of the estimated cost of construction. Any unused balance of the deposits
remaining after completion and acceptance of the construction shall
be refunded.
The applicant for the connection of any building
sewer to a Village sewer system shall notify the Water and Sewer Board
when the building sewer is ready for inspection and connection to
the Village sewer. In no case shall any underground portions of the
building sewer be covered or connection to the Village sewer made
without the approval and/or supervision of the Water and Sewer Board.
Trenches refilled prior to inspection will have to be reopened by
the contractor or owner at no expense to the Village. The building
sewer may be put into use only after satisfactory final inspection
has been made and approval given by the Water and Sewer Board.
The size, slope, alignment, materials or construction
of a building sewer and its appurtenances and the methods to be used
in excavating, placing of the building sewer pipe, jointing, testing
and backfilling the trench shall conform to the requirements and specifications
for the installation of building sewers as adopted by the Board of
Trustees and all applicable provisions of any other rules and regulations
of the Village or of the County of Orange or the State of New York,
whichever requirement is most strict. In the absence of any requirements
or in the amplification thereof, the materials and procedures set
forth in appropriate specifications of the American Society for Testing
and Materials (ASTM) and Water Pollution Control Federation (WPCF)
Manual of Practice No. 9 shall apply. Any deviations from the prescribed
materials and construction procedures must be approved by the Water
and Sewer Board prior to installation.
All building sewer excavations shall comply
with all federal, state and local safety regulations and shall be
adequately guarded with barricades and lights so as to protect the
public from hazard. Streets, sidewalks, parkways and other public
property disturbed in the course of work shall be restored in a manner
satisfactory to the Water and Sewer Board and other appropriate municipal
authorities.
A. Connection fittings.
(1) Connections of the building sewer into the Village
sewer shall use the wye branch or tee as installed in the Village
sewer if such wye branch is available at a suitable location. If no
fitting is available or is not at a suitable location on the Village
sewer, then the property owner shall install, at his own expense,
a wye or tee in the Village sewer at the location specified by the
Water and Sewer Board.
(2) As an alternate, special fittings, such as saddle
hub tees, may be used for the connection when approved by the Water
and Sewer Board. In this case, a neat hole may be cut in the Village
sewer to receive the saddle hub tee. The invert of the building sewer
at the point of connection shall be at the same or at a higher elevation
than the invert of the Village sewer. A smooth, neat joint shall be
made between the saddle hub tee and the Village sewer and the connection
made secure and watertight by encasement in concrete.
B. In the case of undeveloped property, where a building
sewer connection may not have been provided at the property line (or
permanent easement boundary), the property owner will be required,
if and when a sewer connection becomes necessary, to construct, at
his own expense, such a building sewer from the Village sewer to his
building drain.
C. The building sewer pipe shall be Schedule 35 PVC pipe,
a minimum of four inches in diameter, and shall be laid at a depth
sufficient to afford protection from frost and at a uniform grade
of 1/4 inch per foot [or about 2%]. Special permission may be given
by the Water and Sewer Board to use a lesser grade, which in no case
shall be less than 1/8 inch per foot [or about 1%].
D. No building sewer shall be laid within three feet
of and parallel to any bearing wall.
E. Necessary changes in direction shall be made only
with properly curved pipe and fittings. Ninety-degree bends are not
acceptable. Two forty-five-degree bends connected with a one-foot
nipple or a ninety-degree long sweep must be installed where needed.
F. All excavations must be properly refilled to grade
in compacted layers and the original type of surface replaced.
G. The opening of streets and sidewalks for the purpose
of making sewer connections must be done in accordance with the requirements
of Village Law and of the County and State Highway Department, as
applicable. Any required highway work permit shall be obtained by
the property owner or his contractor. Whenever construction is necessary
in any street or road, the Water and Sewer Board may cause the work
to be performed by the Village and bill the property owner for all
expenses.
H. All excavations required for the installation of a
building sewer shall be open trench work unless otherwise approved
by the Water and Sewer Board.
I. Building sewers and water service branches or connections
shall not be laid in the same trench and shall be separated by at
least 10 feet. A minimum eighteen-inch vertical separation shall be
maintained between water and sewer facilities under all circumstances.
Any building sewer installation in the vicinity of any water main
or water service pipe shall conform to all requirements of the Department
of Health. Whenever the construction of sewer facilities is taking
place in close proximity to a water service branch or connection,
the Water and Sewer Board may cause the work to be performed by the
Village and may bill the property owner for all expenses.
J. Whenever possible, the building sewer shall be brought
to the building at an elevation below the basement floor. In all buildings
in which any building drain is too low to permit gravity flow to the
public sewer, sewage carried by such building drain shall be lifted
by a method approved by the Water and Sewer Board and discharged to
a gravity flow building sewer. No water-operated sewage ejector shall
be used.
K. All joints and connections shall be made gas- and
water tight. Joints shall be made with approved materials in accordance
with the latest requirements of the building code. The joint between the building drain and building sewer
shall be of the compression type. Where materials change, i.e., cast
iron to clay, a compression adapter shall be used. Adapters acceptable
are either those furnished and manufactured by the manufacturer for
use with his pipe or an equal approved by the Water and Sewer Board.
L. Cleanouts extending up to ground level (to grade)
must be spaced not more than 100 feet apart along the building sewer.
When they are required, the type and details of all building sewer
cleanouts must be approved by the Water and Sewer Board.
A. All building drains shall be in accordance with the
New York Building Construction Code, applicable to plumbing, 1973,
including latest revisions.
B. All building drains shall include:
(1) A cleanout to a point at least three inches above
final grade located outside the foundation wall.
(2) A double-hand hole building trap installed inside
the foundation wall.
(3) A fresh-air inlet to the outside.
C. All cleanouts to grade shall use four-inch minimum
diameter cast-iron riser, topped with a four-inch brass cleanout plug
(raised square head design). The cleanout plug shall be installed
using pipe thread compound. Joints in the cleanout riser must be rubber
gasketed or caulked lead and oakum. No cemented joints are allowed.
D. All building drain cleanouts shall use a cast-iron
combination wye and one-eighth bend (long turn pattern only) at the
base in the drain with the cast-iron cleanout riser extending vertically
to a point at least three inches above final grade.
E. Where the building drain is located under the basement
floor, all cleanout risers shall be extended to raise the cleanout
plugs up to the level of the basement floor.
F. All cleanouts shall be double direction in order to
facilitate cleaning in both directions.
G. All building traps shall be cast-iron double-hand
hole running traps incorporating two brass cleanout plugs, having
a minimum diameter of four inches. The cleanout plugs shall be installed
using pipe thread compound.
H. The building trap shall be located as close to the
foundation wall as possible. No connections shall be made downstream
of this trap.
I. For basement facilities, the Water and Sewer Board
may require a backwater valve on the main building drain. As an alternate,
a smaller backwater valve may be installed on each separate basement
connection to the building drain, such as on washing machines, sinks,
toilets, etc.
J. All backwater valves, whether installed in the main
building drain or in separate connections to the building drain, shall
incorporate a cleanout and be of a type approved by the Water and
Sewer Board.
K. Fresh-air inlet pipes shall be cast iron, copper or
plastic having a minimum diameter of three inches.
L. The fresh-air inlet shall terminate outside the building
at least six inches above final grade and shall be a U-bend, with
opening facing downward. The open end shall be protected by a bugproof
plate or cap, permanently fixed in the mouth of the pipe, with an
open ventilating area at least equal to the area of the inlet pipe.
M. Upon request, the Village will supply a typical building
drain layout illustrating the requirements of this Part 1.
[Amended 1-19-1999 by L.L. No. 2-1999]
Sanitary sewers shall not be less than eight
inches in diameter and/or adequate size and capacity to serve their
tributary area on the design basis of 100 gallons of average daily
flow per capita per day contributed by the estimated tributary population.
Also included shall be a design allowance for groundwater infiltration
of 150 gallons per inch of pipe diameter per mile of pipe per day.
Slope of the sanitary sewers shall be such so as to provide a minimum
velocity of two feet per second or maximum velocity of 15 feet per
second when said sewer is flowing full and the pipe roughness coefficient
of .013 is utilized. The methods, practices and materials used in
construction of sanitary sewers shall be in accordance with all rules,
regulations and specifications of this Part I and those of the Department
of Health and the NYSDEC, as well as any other local, state and federal
requirements which may apply. In the absence of any such standards,
the materials and procedures of ASTM Manual of Practice No. 9 shall
apply.
The Village reserves the right to specify and
require the encasement of any sewer pipe in concrete or the installation
of the sewer pipe in concrete cradles if foundation and construction
conditions are such as to warrant such protection in the opinion of
the Water and Sewer Board.
Concrete, steel or corrugated metal pipe of
suitable diameter and thickness or tunnel liners of adequate internal
diameter shall be installed for encasement or enclosure of sanitary
sewers to be constructed under all railroads and where directed by
the Water and Sewer Board for the crossing of main highways.
A. Manholes.
(1) Manholes shall be constructed of concrete bases, precast
reinforced manholes, polyethylene-coated steel steps or equal aluminum
steps, with heavy frames and covers. Manholes shall be constructed
with a five-inch minimum wall thickness on all barrel sections. Cone
section wall thickness shall vary from five inches at the bottom to
eight inches at the top of all cone sections.
(2) Manhole bases shall be poured concrete a minimum of
eight inches thick and poured on dense, compacted soil. Concrete used
for manhole bases shall be one-to-two-to-three mix with a maximum
water-cement ratio of six gallons per sack.
(3) Invert channels shall be smooth and accurately shaped.
Invert may consist of half pipe laid in the concrete base or be constructed
by laying full-section sewer pipe straight through the manhole and
cutting out the top half after the concrete base is constructed and
sufficiently set.
(4) Precast reinforced concrete manholes as manufactured
by Fort Miller Co., Inc., or equivalent.
(5) Precast reinforced concrete manholes shall have elastomeric
gaskets at all joints between sections of manhole.
(6) The outside of precast reinforced concrete manholes
shall be coated with an approved sealant in a manner to ensure that
the manhole will be watertight.
(7) Manholes shall have polyethylene coated steel steps
manufactured with Alcoa No. 160278 or equal aluminum.
(8) Steps shall be not less than 10 inches wide, project
six inches into the manhole and shall have not greater than a twelve-inch
vertical separation.
(9) Heavy manhole frames and covers shall be Campbell
Foundry Co. Catalog No. 1104 or equal. All manhole lids shall have
the inscription "sewer" in letters three inches tall and raised 1/16
inch. Frames and covers shall have a maximum weight of 400 pounds
and shall be a minimum of 27 inches in diameter.
(10)
Precast manholes shall be placed at a maximum
of 300 feet apart.
B. Excavations.
(1) All excavation for pipe shall be carried six or more
inches deeper than final pipe grade line and then brought to grade
with sand or pea gravel. This bedding shall have a width equal to
the width of the sewer trench at the top of the pipe.
(2) The width of the sewer trench at the top of the pipe
shall be the diameter of the pipe plus 12 inches on each side. Excavation
for manholes shall have twelve-inch minimum and twenty-four-inch maximum
clearance on all sides.
[Amended 1-19-1999 by L.L. No. 1-1999]
(3) Materials such as peat or other soft material shall
be removed and replaced with suitable materials. In the event that
rock is encountered, excavation shall be carried eight inches below
the bottom of the pipe and loose earth or gravel shall be used for
backfill and tamped thoroughly and rounded to receive pipe.
(4) The contractor shall remove, by pumping or other means,
any water accumulated in the excavation and shall keep the trench
dewatered until the bedding and pipe installation is completed.
[Amended 1-19-1999 by L.L. No. 1-1999]
(5) The contractor shall do all bracing, sheathing and
shoring necessary to perform and protect all excavation as required
for safety or to conform to governing laws.
C. Backfilling.
(1) No pipe, manhole or other appurtenances shall be backfilled
until inspected and approved by the Engineer or a duly authorized
representative.
(2) General backfill and fill materials. The contractor
shall provide approved soil materials for backfill and fill which
shall be free of clay, rock larger than six inches in any dimension,
debris, waste, frozen materials and vegetable, organic and other deleterious
matter.
[Amended 1-19-1999 by L.L. No. 1-1999]
(3) Immediately after the pipes have been laid, backfilling shall be done with approved material. It is the responsibility of the contractor to assure that backfill is sufficient to limit pipe deflection to no more than 5%. The material surrounding the pipe shall be carefully placed and carefully backfilled and tamped so as to have a thoroughly compacted material (to 95% modified proctor under roadways and 90% in other areas) but tamped in such a manner that the line and grade of pipe are not disturbed. Backfill material shall be placed evenly and carefully above the pipe in six-inch layers, and each layer shall be thoroughly tamped until one foot of cover exists over the pipe. This portion of the backfill shall contain no stone larger than two inches in diameter. The remainder of the backfill may be material excavated from the trench containing no stones larger than six inches in diameter but shall be carefully placed and compacted. (If the contractor wishes to use excavated trench material, such material shall be stockpiled and tested in accordance with ASTM D698, Method C, including Note 2, so that proctor testing baseline can be established. Testing shall be performed by an approved laboratory. Until excavated material is tested and approved, the contractor shall utilize backfill material specified in Subsection
B(4) below.) This additional material shall extend to within 18 inches of the road and shall extend to ground surface where the sewer is in a right-of-way. In the road surfaces, the last 18 inches of fill over the pipe shall be suitable run-of-bank approved by the Engineer.
[Amended 1-19-1999 by L.L. No. 1-1999]
(4) Suitable backfill.
[Amended 1-19-1999 by L.L. No. 1-1999]
(a)
If, in the opinion of the Engineer, the material
excavated from the trench is not suitable to be used as backfill,
the Engineer may direct that the trench be backfilled with well-graded
granular material or run-of-bank gravel free from organic matter conforming
to NYSDOT Item 304.02, Type I, with the following gradation:
Size
|
WT Percent Passing
|
---|
3 inches
|
100
|
2 inches
|
90-100
|
1/4 inch
|
30-65
|
No. 40
|
5-40
|
No. 200
|
0-10
|
(b)
A sample of the material shall be submitted
for approval. The Engineer shall be advised in writing of its source
and furnished with certification of conformance with the specification.
D. Materials.
(1) Sanitary sewer pipe shall have a minimum diameter
of eight inches and shall be polyvinyl chloride (PVC) gravity sewer
pipe conforming to all aspects of ASTM Specification D3034 for integral
bell gasketed joint PVC sewer piping product with SDR 35 and minimum
pipe stiffness of 46 pounds per square inch (psi). Each standard and
random length of pipe and all fittings in compliance with this standard
shall be clearly marked as per the following example at intervals
of 12.5 or 20.0 feet:
(a)
Manufacturer's name and trademark.
(d)
Legend: Classification Type PSM SDR35 PVC Sewer
Pipe.
(2) Joints shall be rubber gas jetted bell and spigot
type. Pipe joints shall comply with Uni-Bell Standard UNI-B-1 and
ASTM D3212.
(3) Sanitary sewage pumping stations and force mains shall
be of a size and capacity as decided by the Village Board on an individual
basis.
E. Materials and procedure.
(1) When pipe foundation conditions at the bottom of the
trench are satisfactory to the Engineer, the contractor shall place
a standard bedding of six inches of material specified herein for
all PVC pipe and lay pipe on this bedding. Hunching material, also
of material specified herein, shall be carefully placed up to the
spring line of the pipe with special attention paid to the consolidation
of the material under the pipe haunch. The top of the standard bedding
shall be brought carefully to the proper grade for the barrel of the
pipe. Bedding and hunching shall be well tamped or compacted in a
manner satisfactory to the Engineer. The material shall be deposited
in layers of not more than six inches in depth, with each layer thoroughly
compacted before the addition of other layers.
[Amended 1-19-1999 by L.L. No. 1-1999]
(a)
Thermoplastic pipe embedment material shall
conform to AASHTO M43, Size 78, meeting the following gradation:
Size
|
WT Percent Passing
|
---|
3/4 inch
|
100
|
1/2 inch
|
90-100
|
3/8 inch
|
40-75
|
No. 4
|
5-25
|
No. 8
|
0-10
|
No. 16
|
0-5
|
(b)
Where thermoplastic and other pipe are installed
in a common trench bottom, thermoplastic embedment material shall
be used.
(2) All sewers shall be laid true to line and grade and
such that the bell ends will be uphill. The sections of the pipe shall
be so laid and fitted together that, when complete, the sewer will
have a smooth and uniform invert. The pipe shall be kept thoroughly
clean so that joining compounds will adhere. The contractor shall
close the ends of all unconnected pipe with a waterproof stopper.
Each pipe shall be inspected for defects before being lowered into
the trench. Water shall not be allowed in the trenches while the pipes
are being laid. Not more than 50 feet of trench shall be opened in
advance of pipe laying unless permitted by the Engineer.
(3) All jointing of pipe shall be in the dry. For polyvinyl
chloride pipe, the gaskets and mating surfaces of the pipe shall be
thoroughly cleaned and lubricated prior to installation. Align pipe
to be installed with previously installed pipe and, with gasket in
place, put joint together. After pipes are put together, inspect joint
to verify that gasket is properly positioned and that joint has been
properly made and is tight. If, while making the joint, the gasket
becomes loose or cut, the pipe shall be removed and the joint remade
to the satisfaction of the Engineer. Joints shall be made watertight.
(4) Holes under joints shall be filled with one-fourth-inch
pea gravel or sand bedding material, and compact the material thoroughly.
Place one-fourth-inch pea gravel against both sides of the pipe so
that all space in the trench on each side of pipe is entirely filled
and well compacted.
(5) The excavation of trenches shall be fully completed
a sufficient distance in advance of laying of the sewer, and the exposed
end of all pipe shall be fully protected with a board or other approved
stopper to prevent earth or other substances from entering the pipe.
The interior of the sewer shall be carefully freed from all dirt or
superfluous material of every description as the work progresses.
Pipes shall be thoroughly flushed at the completion of the work of
laying and jointing.
(6) Manholes shall be built up so that the cover, when
placed, will be at the required grade. All manhole frames shall be
properly grouted in place.
F. Connections; required methods.
(1) All pipe for service connections shall be four-inch
minimum diameter pipe of the same class as the main sewer pipe and
shall be capped with standard manufactured plugs until ready for use.
(2) No pipe shall be cut for connections except when permitted
by the Engineer. Wyes and tees for service connections shall be installed
as required. The ends of pipe which enter masonry shall be neatly
cut to fit the inner face of the masonry. Joints shall not be covered
until approved by the Engineer.
(3) An accurate as-built record shall be kept for all
service connections. The record shall show the location and elevation
of each service connection. These records shall be turned over to
the Water and Sewer Board of the Village of Montgomery when the sanitary
sewers are accepted by the Village of Montgomery.
(4) Duplicate delivery tickets shall be kept by the contractor
for all materials used for the construction of sanitary sewers and
appurtenances. These delivery tickets shall be turned over to the
Engineer upon his request.
G. Tests.
(1) Infiltration. Tests for watertightness which are required
by the Water and Sewer Board or Engineer shall be made by the contractor
in the presence of the Engineer, and the sewer connections shall not
leak under the exterior normal groundwater pressure in excess of a
rate of 50 gallons per inch of diameter per mile per 24 hours. The
tests and the measurement of infiltration shall be conducted in a
manner as approved by the Water and Sewer Board or Engineer.
(2) Exfiltration. Tests shall be made by air testing by
a method approved by the Engineer.
(3) Deflection. Tests for maximum pipe deflection after
backfilling shall be conducted by the contractor in the presence of
the Engineer. At least 10% of pipe shall be tested, with selection
of time and location to be made by the Engineer. All pipe not passing
the five-percent deflection limitation test shall be removed and replaced.
At the discretion of the Engineer, should deflections be noted excessive,
100% of pipe in the project may be tested.
(4) Final inspection. No sanitary sewers will be accepted
by the Village of Montgomery until a final inspection using flashlights
and/or mirrors has been made by the Water and Sewer Board or Engineer.
(5) Manholes. All manholes less than six feet in diameter
shall be vacuum tested in accordance with the following procedure:
[Added 1-19-1999 by L.L. No. 1-1999]
(a)
All lift holes shall be filled with a rubber
plug and coated with an approved nonshrink grout.
(b)
All pipes entering the manhole shall be plugged,
taking care to securely brace the plugs from being drawn into the
manhole. Bracing shall be adequate for the test vacuum applied plus
a suitable factor of safety.
(c)
The test head shall be placed at the inside
of the top of the cone section and the seal inflated in accordance
with the manufacturer's recommendations.
(d)
A vacuum of 10 inches of mercury shall be drawn
and the vacuum pump shut off. With the valves closed, the time shall
be measured with a stopwatch for the vacuum to drop to nine inches.
(e)
The manhole shall pass if the time is greater
than 60 seconds for forty-eight-inch diameter, 75 seconds for sixty-inch
diameter and 90 seconds for seventy-two-inch diameter manholes.
(f)
If the manhole fails the initial test, necessary
repairs shall be made at the contractor's expense. Retesting shall
proceed until a satisfactory test is obtained.
H. Infiltration. Upon completion of construction of the
pipe lines, air testing of the pipes shall be performed under the
supervision of the Engineer. The air testing procedure shall be undertaken
in accordance with the procedure outlined in § 96-291 of
this chapter.
[Amended 1-19-1999 by L.L. No. 1-1999]
I. Exfiltration.
(1) Air testing of PVC sewer pipe shall be carried out
by plugging each end of the line to be tested. A standard Bourdon
gauge must be placed on one end of the pipe. The entire length of
the pipe must be filled with air until a pressure of 3 1/2 pounds
per square inch gauge (psig) is obtained as indicated on the gauge.
The time limit of the test shall be determined by the following formula:
pipe diameter in feet times 462 equals test duration in seconds for
the time duration computed.
(2) The allowable pressure drop shall not exceed 0.5 psig.
(3) Only lines tested after backfilling to final grade
will be considered for acceptability; however, this test may also
be used by the contractor as a presumptive test to determine the condition
of the line prior to backfilling.
(4) The air testing procedure shall be undertaken in accordance
with the following procedure:
(a)
After a manhole to manhole reach of pipe has
been backfilled to final grade, prepared for testing and the specified
waiting period has elapsed, plugs shall be placed in the line at each
manhole and secured.
(b)
Low-pressure air shall be slowly introduced
into the sealed line until the internal air pressure reaches 4.0 psig
greater than the average back pressure of any groundwater above the
pipe, but no greater than 9.0 psig. If groundwater is present, the
air-test pressure shall be adjusted as specified below.
(c)
After a constant pressure of 4.0 psig (greater
than the average groundwater back pressure) is reached, the air supply
shall be throttled to maintain that internal pressure for at least
two minutes. This time permits the temperature of the entering air
to equalize with the temperature of the pipe wall.
(d)
When temperatures have been equalized and the
pressure stabilized at 4.0 psig (greater than the average groundwater
back pressure), the air hose from the control panel to the air supply
shall be shut off or disconnected. The continuous monitoring pressure
gauge shall then be observed while the pressure is decreased to no
less than 3.5 psig (greater than the average back pressure of any
groundwater over the pipe). At a reading of 3.5 psig or any convenient
observed pressure reading between 3.5 psig and four and zero-tenths
psig (greater than the average groundwater back pressure), timing
shall commence with a stopwatch or other timing device that is at
least 99.8% accurate.
(e)
If the time shown in Table 1 for the designated pipe size and length elapses before
the air pressure drops 0.5 psig, the section undergoing test shall
have passed and shall be presumed to be free of defects. The test
may be disconnected once the prescribed time has elapsed even though
the drop of 0.5 psig had not occurred. If the pressure drops 0.5 psig
before the appropriate time shown in Table 1 has elapsed, the air
loss rate shall be considered excessive, and the section of pipe has
failed the test.
(f)
If the section fails to meet these requirements,
the contractor shall determine, at his own expense, the source or
sources of leakage, and he shall repair or replace all defective materials
and/or workmanship to the satisfaction of the Engineer. The extent
and type of repair which may be allowed, as well as results, shall
be subject to the approval of the Engineer. The completed pipe installation
shall be retested and required to meet the requirements of the test.
(g)
Immediately before air testing, the groundwater
level shall be determined. The contractor shall be responsible for
providing, installing and maintaining suitable groundwater gauges
along the entire route of the gravity sewer lines in order to determine
groundwater levels for test procedures. Prior to the testing, a measurement
of the height in feet of water over the invert of sewer pipe shall
be taken.
(h)
Should groundwater exist over the pipe invert,
an air-test pressure adjustment is required. The air pressure correction,
which must be added to the normal test starting pressure of 3.5 psig,
shall be calculated by dividing the average vertical height in feet
of groundwater above the invert of the sewer pipe to be tested by
2.31. The result gives the air pressure correction in pounds per square
inch to be added. [For example, if the average vertical height of
groundwater above the pipe invert is 2.8 feet, the additional air
pressure required would equal 2.8 divided by 2.31 or 1.2 psig. This
would require a minimum starting pressure of 3.5 plus 1.2 or 4.7 psig].
The allowable pressure drop of 0.5 psig and the timing in Table 1 are not affected and shall remain the same.
(i)
In no case should the starting pressure exceed
9.0 psig. If the average vertical height of groundwater above the
pipe invert is more than 12.7 feet, the section so submerged may be
tested using 9.0 psig as the starting test pressure.
J. Pipe deflection. Each PVC pipe and section shall be
tested for maximum deflection no less than 30 days after final backfilling
operations have been completed for that pipe section. The pipe shall
be tested by a go-no-go plug device permitting no greater than a maximum
deflection of 5%. The test should be performed without any mechanical
pulling devices.