All extensions to the sanitary sewer system owned and maintained
by the Town shall be properly designed in accordance with the Recommended
Standards for Sewage Works, as adopted by the Great Lakes Upper Mississippi
River Board of State Sanitary Engineers and in strict conformance
with all requirements of the New York State Department of Health.
Plans and specifications for sewer extensions shall be submitted to
and approval obtained from the Engineer and New York State Department
of Health before construction may proceed. The design of sewers must
anticipate and allow for flows from all possible future extensions
or developments within the immediate drainage area.
Sewer extensions, including individual building sewer laterals
to the property line, may be constructed by the Town under public
contract if, in the opinion of the Town Board, the number of properties
to be served by such extension warrants its cost. Under this arrangement,
the property owner shall pay for and install the building sewer from
the property line to his residence or place of business. Thereafter,
each property owner served by the extended public sewers will be charged
at the full service charge rate. Property owners may, in accordance
with applicable law, propose sewer extensions within the Stockport
Sewer District or other parts of the Town by drafting a written petition,
signed by a majority of the benefiting property owners, and filing
it with the Town Board.
If the Town does not elect to construct a sewer extension under
public contract, the property owner, builder or developer may construct
the necessary sewer extension if the extension is approved by the
Town Board in accordance with the requirements of the regulations
set forth herein. Such owner, builder or developer shall pay for the
entire installation, including all expenses incidental thereto. Each
building sewer must be installed and inspected as required by this
chapter, and the inspection fees shall be paid for by the owner, builder
or developer. The installation of the sewer extension must be subject
to full-time inspection by the Town Engineer, and the expenses for
this inspection shall be paid for by the owner, builder or developer.
The Town Engineer's decision shall be final in matters of quality
and methods of construction. The sewer, as constructed, must pass
the exfiltration test before it is to be used. The cost of the sewer
extension thus made shall be absorbed by the owner, builder or developer,
and thereafter all subsequent property owners shall be subject to
a sewer service charge proportional to their use of trunk sewers and
treatment plant and their proportion of operational and maintenance
costs.
All sewer extensions constructed at the property owner's,
builder's or developer's expense, after final approval and
acceptance by the Town Engineer, shall become the property of the
Town and shall thereafter be maintained by the Town. Said sewer extensions,
after their acceptance by the Town, shall be guaranteed for one year.
The guaranty shall be in a form provided for by the Town. At the sole
discretion of the Town, a completion bond or certified check may be
demanded as part of the guaranty.
Pipe of PVC will be allowed under the following conditions,
specifications and installation details:
A.
The maximum size of PVC pipe is limited to 12 inches in diameter
and a depth of cover not to exceed 12 feet. All pipe over this diameter
and/or depth shall be Class 50, cement-lined ductile iron. Residential
services shall be a minimum of six inches in diameter.
B.
Proper and controlled bedding and compaction as hereinafter specified
shall be required.
C.
In addition to the normal low pressure, air testing for acceptance
of new sanitary sewers and services, a deflection test of all main
line PVC sewers will be required no sooner than 60 days after sewer
installation and backfill. Deflection testing shall be accomplished
by means of passing a sled or mandrel 1/16 inch smaller in diameter
than the allowable inside diameter of the flexible pipe when deflected
a maximum of 5% of the outside diameter of the pipe being tested.
D.
The minimum depth of cover under pavement or in areas with a superimposed
load without concrete encasement or other form of protection and bedding
will be four feet.
A.
All pipe and fittings shall conform to the Standard Specifications
for Type PSM (Polyvinyl Chloride) (PVC) Sewer Pipe and Fittings, ASTM
Designation, D-3034-82, or latest revision, and to the dimensions
and tolerances of classification SDR-35 or SDR-35-26.
B.
Pipe-laying lengths shall not exceed 20 feet in length. Pipe and
fittings within the right-of-way or easement limits, including house
services, shall be furnished with flexible joints employing a solid
elastomeric gasket to provide a watertight seal.
A.
Pipe of PVC furnished shall conform to the requirements of ASTM D-3212-82,
or latest revision, for push-on-type joints consisting of a bell end
or socket and a spigot end. All gaskets shall be extruded or molded
and cured in such a manner that any cross section will be dense, homogeneous
and free from any imperfections. The gasket shall be fabricated from
a high-grade elastomer compound meeting the requirements of ANSI/ASTM
F477-76.
B.
Where the particular joint design dictates the use of a lubricant
to facilitate assembly, the lubricant shall be of such composition
which will in no way damage the gasket or pipe due to prolonged exposure.
The lubricant shall be furnished by the pipe manufacturer and applied
in accordance with the manufacturer's instructions.
The homeowner will be allowed to install ABS SDR-23.5 with solvent
weld joints under the following conditions:
A.
The service line will be below four feet in depth, or the length
of the line will not exceed 60 feet without the use of an approved
expansion joint.
A.
"Pipe zone" is that area from the bottom of the pipe barrel to the
top of the pipe barrel for the full trench width.
B.
Bedding material under and up to the spring line of the pipe shall
consist of Class II materials, course sands and gravels containing
small percentages of fine, generally granular and cohesive, either
wet or dry.
C.
Gradations, other than well graded, such as uniformly graded or gap
graded, that may permit loss of pipe support by migration into void
spaces of a finer natural material from the trench wall and bottom
will not be allowed.
D.
The bedding material under the pipe shall be firmly compacted to
bring the pipe to the proper grade. The bedding material under the
pipe haunches shall be firmly compacted by hand-tamping with bar tampers
and shall be hand- or mechanically tamped in six-inch layers on either
side of the pipe with flat tampers to the pipe spring lines. Care
shall be taken to avoid vertical or lateral displacement of the pipe
during compaction.
E.
If the existing material removed from the trench is not suitable
for backfilling around the pipe, an approved select granular material
shall be placed in six inch layers and compacted from the pipe spring
line to a minimum of 12 inches above the pipe barrel, as shown on
the attached Trench Detail.[1]
[1]
Editor's Note: Detail diagrams are included as attachments
to this chapter.
Manholes shall be constructed at all changes in slope alignment
or at intervals not exceeding 400 linear feet. The manholes shall
be constructed with a poured three-thousand-pound-per-square-inch
concrete base, steel-troweled concrete or mortar inverts and precast
four-foot-diameter concrete manhole barrel sections and a tapered
top section. The manhole frame and cover shall be the standard design
of the Town and shall be set with no less than two courses of brick
underneath to allow for later adjustment in elevation. "Town of Stockport"
should be added on the lid.
A press-wedge seal or equal shall be used to connect PVC pipe
to manholes, as shown on the Manhole Connection Detail.
A.
Final exfiltration test.
(1)
All sewers shall satisfy requirements of a final exfiltration test
before they will be approved and sewage flow accepted from them by
the Town. This test consists of filling the pipe with water to provide
a head of at least five feet above the top of the pipe or five feet
above groundwater, whichever is higher, at the highest point of the
pipeline under test and then measuring the loss of water from the
line by the amount which must be added to maintain the original level.
In this test, the line must remain filled with water for at least
24 hours prior to the taking of measurements. Exfiltration shall be
measured by the drop of water level in a standpipe with closed bottom
end or in one of the sewer manholes available for measurement.
(2)
When a standpipe and plug arrangement is used in the upper manhole
of a line under test, there must be some positive method of releasing
entrapped air in the sewer prior to taking measurements. The test
length intervals for either type of test shall be as ordered approved
but in no event shall they exceed 100 feet. In the case of sewers
laid on steep grades, the length of line to be tested by exfiltration
at any one time may be limited by the maximum allowable internal pressure
on the pipe and joints at the lower end of the line. The test period,
wherein the measurements are taken, shall not be less than two hours
in either type of test.
(3)
The total leakage of any section tested shall not exceed the rate
of 100 gallons per mile of pipe per 24 hours per inch of nominal pipe
diameter. For purposes of determining the maximum allowable leakage,
manholes shall be considered as sections of forty-eight-inch-diameter
pipe, five feet long. The equivalent leakage allowance shall be 4.5
gallons per manhole per 24 hours for forty-eight-inch-diameter manholes.
If leakage exceeds the specified amount, the necessary repairs or
replacements required shall be made to permanently reduce the leakage
to within the specified limit, and the tests shall be repeated until
the leakage requirement is met.
B.
Low-pressure air testing.
(1)
Air shall be slowly supplied to the plugged pipe installation until
the internal air pressure reaches 4.0 pounds per square inch greater
than the average back pressure of any groundwater that may submerge
the pipe. At least two minutes shall be allowed for temperature stabilization
before proceeding further.
(2)
The rate of air loss shall then be determined by measuring the time
interval required for the internal pressure to decrease from 3.5 pounds
per square inch to 2.5 pounds per square inch.
(4)
Air testing shall be no sooner than two weeks after installation
of the sewer mains nor one week prior to pavement restoration over
the sewers, except as approved by the Town, in writing.
(5)
Areas that are extremely wet which require well-pointing for the
proper installation of sewers shall be air tested before the dewatering
operations are terminated.
(6)
Each section of sewer between manholes shall show a full circle of
light from either end when lamped.
C.
Additional testing. The Town of Stockport reserves the right to have
the contractor perform additional hydrostatic tests, before acceptance
of sewer sections, which indicate that the rate of air loss per unit
of surface area most nearly approximates the rate for sewer pipe acceptance.
These additional tests used shall be by direct measurement of infiltration
or exfiltration.
(1)
Direct measurement of infiltration. Weir measurement shall be used
for infiltration tests only; a calibrated weir designed for insertion
into the pipe shall be used. This test could be required in addition
to the exfiltration; however, it will only be required when groundwater
is present and at a minimum of two feet over the top of the pipe.
(2)
Direct measurement of exfiltration.
(a)
Groundwater elevations at the time of testing shall be determined
by means of test holes made by the contractor at intervals along the
line to be tested. The maximum length of line to be tested shall not
exceed 1,000 feet. The maximum permissible exfiltration rate shall
be 50 gallons per inch of diameter, per mile of pipe per day, under
a differential head of not less than four feet nor more than 10 feet.
(b)
The infiltration and exfiltration tests shall extend over a
period of not less than 24 hours. The initial reading shall be taken
at the start of the working day and followed by not less than seven
consecutive hourly readings. An additional reading shall be made 24
hours after the initial reading.
Three approved manufacturers of PVC, SDR-35, are Certain-Teed,
Johns Manville and Clow Corporation.
The size and grade of house laterals and other applicable installation
requirements and details shall conform to the Town of Stockport Sanitary
Sewer Informational Pamphlet for Residential Connections, dated November
1989.
A.
In constructing the sanitary sewer system, the contractor will install
a four-inch PVC pipe with rubber O-ring gaskets up to the individual's
property line.
B.
After obtaining a sewer permit from the Receiver of Taxes at the
Town Hall, the cost of which shall be set from time to time by resolution,
the property owner or his agent shall continue the house lateral with
four-inch PVC pipe or ABS pipe to within five feet of the point of
entry through the foundation. This pipe shall have a minimum slope
of 1/4 inch per foot. The connecting pipe from inside the house shall
be a minimum of four-inch cast-iron pipe and above the cellar floor.
Where possible, sewer connections should be made directly in the front
of the building.
C.
All sewer lines from the property line to the foundation wall must
be inspected before backfilling. Failure to have such inspection will
necessitate reopening of the trench. Notice shall be given to the
Town of Stockport Wastewater Superintendent by the owner or his agent
when the work is ready for inspection. No part of the work shall be
covered until examined and approved by the department representative.
If the line is more than 75 feet, an outside cleanout is required.
No ninety-degree corners will be allowed.
D.
A building trap shall be provided with two brass cleanout plugs.
Cleanout plugs shall be located at the trap for cleaning the trap
interior and for rodding upstream and downstream from the trap. The
building trap shall be located inside the building, wherever practicable
within two feet of the exterior wall of the structure and on the sewer
side of all connections. Where the cleanouts of such traps are located
underground, an approved masonry or concrete pit or manhole shall
be provided for access to the cleanouts. Every sanitary building drain
shall be provided with a fresh air inlet pipe connected to the building
drain immediately upstream from and within four feet of the trap.
The fresh air inlet shall be extended to the outer air and shall be
terminated in an open end at least six inches above grade. The open
end shall be protected by a perforated metal plate permanently fixed.
The inlet pipe shall be at least three inches in size.
E.
Plastic piping is permitted for use for the interior plumbing system.
Plastic piping will be permitted for use upstream from the cast-iron
trap. The plastic pipe shall be of the rigid type and must be approved
for use for sanitary waste drainage piping. ABS or PVC, DWV Schedule
40 or heavier shall be used.
F.
All plumbing construction shall conform to the New York State Uniform
Fire Prevention and Building Code applicable to plumbing, Bulletin
Number 23, with amendments.
G.
Basement toilets, washing machines or tubs shall have a backwater
valve in the line.
H.
At the time of changeover to the sanitary sewer system, all other
methods of sanitary sewage disposal must be disconnected. No cellar
floor drains, foundation drainage, downspouts or other sources of
uncontaminated water may be connected to the sanitary sewer system.
Any septic tank, cesspool and similar private sewage disposal facilities
shall be abandoned, cleaned of sludge and filled with clean fill.
The opening from the septic tank to the leach field should be plugged
with concrete.
