When a property owner, builder, or developer proposes to construct sanitary sewers or extensions to sanitary sewers in an area proposed for subdivision, the plans, specifications, and method of installation shall be subject to the approval of the Superintendent and the NYSDEC in accordance with §
91-28. Said property owner, builder, or developer shall pay for the entire installation, including a proportionate share of the treatment plant, intercepting or trunk sewers, pumping stations, force mains, and all other POTW expenses incidental thereto. Each street lateral shall be installed and inspected pursuant to Article
VI, and inspection fees shall be paid by the applicant prior to initiating construction. Design and installation of sewers shall be as specified in §§
91-30 through
91-30.3, and in conformance with Paragraphs 3 through 6 of ASTM Specification C-12. The installation of the sewer shall be subject to periodic inspection by the Superintendent without prior notice. The Superintendent shall determine whether the work is proceeding in accordance with the approved plans and specifications, and whether the completed work will conform to the approved plans and specifications. The sewer, as constructed, must pass the infiltration test (or the exfiltation test, with prior approval), required in §§
91-32 through
91-32.6, before any building lateral is connected thereto. The Superintendent shall be notified 30 days in advance of the start of any construction actions so that such inspection frequencies and procedures as may be necessary or required, may be established. No new sanitary sewers will be accepted by the Town Board until such construction inspections have been made so as to assure the Town Board of compliance with this chapter and any amendments or additions thereto. The Superintendent has the authority to require such excavation as necessary to inspect any installed facilities if the facilities were covered or otherwise backfilled before they were inspected so as to permit inspection of the construction. The Superintendent shall report all findings of inspections and tests to the Town Board.
Plans, specifications, and methods of installation shall conform to the requirements of this article. Components and materials of wastewater facilities not covered in this chapter, such as pumping stations, lift stations, or force mains, shall be designed in accordance with §§
91-28, and shall be clearly shown and detailed on the plans and specifications submitted for approval. Force main details are covered in §
91-33 and
91-33.1. When requested, the applicant shall submit, to the Superintendent and to the NYSDEC, all design calculations and other pertinent data to supplement review of the plans and specifications. Results of manufacturer's tests on each lot of pipe delivered to the job site shall also be furnished, upon request.
Sewer pipe material shall be:
A. Polyvinyl chloride (PVC) pipe: heavy wall.
(1) Pipe shall be made from Class 12454-B materials or better in accordance
with ANSI/ASTM Specification D-1784.
(2) Pipe and accessories shall conform to the requirements of the following,
with a minimum pipe stiffness of 46.
(3) PSI at a maximum deflection of 5%.
(4) ANSI/ASTM D 3034 (4" - 15").
(5) ASTM F 679 Type I (18" - 27").
B. Ductile iron pipe.
(1) Pipe, fittings, and specials shall be manufactured in accordance
with ASTM Specification A-746.
(2) Pipe shall have a minimum thickness of Class 50.
(3) Fittings shall conform to ANSI Specification A-21.11 and have a minimum
pressure class rating of 150 PSI. All pipe and fittings shall be cement-mortar-lined
in accordance with ANSI Specification A-21.4 at twice the specified
thickness, and have an internal and external bituminous seal coating.
(4) Closure pieces shall be jointed by means of a mechanical coupling
of the cast sleeve type.
C. Acrylonitrile-butadiene-styrene (ABS) pipe.
(1) Pipe and fittings shall conform to the requirements of ASTM Specification
D2661.
D. Other pipe materials.
(1) Other pipe materials require prior written approval of the Superintendent
before being installed.
(a)
The minimum internal pipe diameter shall be eight inches for
gravity sewers and three inches for low-pressure sewers.
(b)
Joints for the selected pipe shall be designed and manufactured
such that "O" ring gaskets of the "snap-on" type are used.
(c)
Gaskets shall be continuous, solid, natural or synthetic rubber, and shall provide a positive compression seal in the assembled joint, such that the requirements of §§
91-32 through
91-32.6 are met.
(d)
Joint preparation and assembly shall be in accordance with the
manufacturer's recommendations.
(e)
Wye branch fittings, as approved by the Superintendent, shall be installed, for connection of street laterals, in accordance with §§
91-41 through
91-41.2.
All sanitary sewers or extensions to sanitary sewers, including
manholes, shall satisfy requirements of a final infiltration test
before they will be approved and wastewater flow permitted by the
POTW. The infiltration rate shall not exceed 25 gallons per 24 hours
per mile per nominal diameter in inches. An exfiltration test may
be substituted for the infiltration test; the same rate shall not
be exceeded. The exfiltration test shall be performed by the applicant,
under the supervision of the Superintendent, who shall have the responsibility
for making proper and accurate measurements required. The exfiltration
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 under test, and then measuring
the loss of water, from the pipe section under test, by the amount
of water which must be added to maintain the original level. However,
under no circumstances shall the head at the downstream manhole exceed
10 feet or fill to within six inches of the top of the downstream
manhole. Should this condition prevail, the testing methods in §§ 91-31.5
and/or 91-31.6 shall be utilized. In this test, the test section must
remain filled with water for at least 24 hours prior to taking any
measurements. Exfiltration shall be measured by the drop of water
level in a standpipe with a closed bottom end, or in one of the sewer
manholes serving the test section. When a standpipe and plug arrangement
is used in the upper manhole in the test section, there shall be some
positive method for releasing entrapped air prior to taking any measurements.
The test section shall be as ordered or as approved, but in
no event longer than 1,000 feet. In the case of sewers laid on steep
grades, the test length may be limited by the maximum allowable internal
pressure on the pipe and joints at the lower end of the test section.
For purposes of determining the leakage rate of the test section,
manholes shall be considered as sections of forty-eight-inch-diameter
pipe, five feet long. The maximum allowable leakage rate for such
a section is 1.1 gallons per 24 hours. If leakage exceeds the allowable
rate, then necessary repairs or replacements shall be made, and the
section retested.
The test period, during which the test measurements are taken,
shall not be less than two hours.
Prior to testing, the section shall be lamped. Any length of
pipe out of straight alignment shall be realigned.
Also prior to testing, all plastic pipe, in the test section,
shall be tested for deflection. Deflection testing shall involve the
pulling of a rigid ball or mandrel, whose diameter is 95% of the pipe
inside diameter, through the pipe. Any length of pipe with a deflection
greater than 5% shall be replaced. The test section shall be flushed
just prior to deflection testing. The test shall not be performed
with a mechanical pulling device.
Force mains serving sewage lifting devices, such as grinder pumps and pump stations, shall be designed in accordance with §
91-28. Additional design requirements are:
A. Force main pipe material shall be:
(1) Ductile iron pipe.
(a)
Pipe shall conform to ANSI A21.51. The minimum wall thickness
shall be Class 52 (ANSI A21.50). The pipe shall be clearly marked
with either "D" or "DUCTILE". Fittings shall conform to ANSI A21.10.
(b)
Pipe and fittings shall be furnished with push-on joints conforming
to ANSI A21.11.
(c)
Pipe and fittings shall be cement-mortar-lined and have an internal
and external bituminous seal coating.
(2) Polyvinyl chloride (PVC) plastic pipe.
(3) Pipe shall conform to ASTM D2241. Materials used in the manufacture
of PVC pipe shall meet ASTM c1784. The minimum wall thickness shall
be SDR-21. Fittings shall conform to ASTM D2241. Joints and gaskets
shall conform to ASTM D2241, D1869, and F477.
(4) Other pipe materials. Other pipe materials require prior written
approval of the Superintendent before being installed.
B. Trenching, bedding, and backfilling shall be in accordance with §
91-30.2.
C. Joint preparation and assembly shall be in accordance with the manufacturer's
written instructions.
D. Anchorages, concrete blocking, and/or mechanical restraint shall
be provided when there is a change of direction of 7 1/2°
or greater.
E. Drain valves shall be placed at low points.
F. Automatic air relief valves shall be placed at high points and at
400-foot intervals, on level force main runs.
G. Air relief and drain valves shall be suitably protected from freezing.
H. When the daily average design detention time in the force main exceeds
20 minutes, the manhole and sewer line receiving the force main discharge
or the sewage shall be treated so that corrosion of the manhole and
the exiting line are prevented. The corrosion is caused by sulfuric
acid biochemically produced from hydrogen sulfide anaerobically produced
in the force main.
I. The force main shall terminate, in the receiving manhole, at a PVC
plastic sewer pipe "T." The vertical arms of the "T" shall be twice
the diameter of the force main. The upper arm shall be at least four
feet long; the lower arm shall terminate in a PVC plastic sewer pipe
ninety-degree elbow in a flow channel directed to the manhole exit
pipe. The "T" and its arms shall be securely fastened to the inside
surface of the manhole wall using corrosion resistant anchors.
All sanitary sewers and extensions to sanitary sewers constructed
at the applicant's expense, after final approval and acceptance
by the Superintendent, and concurrence by the Town Board, shall become
the property of the POTW, and shall thereafter be operated and maintained
by the POTW. No sanitary sewer shall be accepted by the POTW until
four copies of as-built drawings have been so filed with the Superintendent
and the Superintendent has approved the submitted drawings. Said sewers,
after their acceptance by the Town, shall be guaranteed against defects
in materials or workmanship for one year, by the applicant. The guarantee
shall be in such form and contain such provision as deemed necessary
by the Town Board, secured by a surety bond or such other security
as the Town Board may approve.