A.
New sanitary sewers and all extensions to sanitary sewers owned and
operated by the Town of Wilna Sewer District shall be designed, by
a professional licensed to practice sewer design in the State, in
accordance with the Recommended Standards for Sewage Works, as adopted
by the Great Lakes — Upper Mississippi River Board of State
Sanitary Engineers ("Ten State Standards"), and in strict conformance
with all requirements of the NYSDEC. Plans and specifications shall
be submitted to, and written approval shall be obtained from the Superintendent,
the Jefferson County Health Department, and the NYSDEC, before initiating
any construction. The design shall anticipate and allow for flows
from all possible future extensions or developments within the immediate
drainage area.
B.
If, however, there is inadequate capacity in any sewer which would
convey the wastewater or if there is insufficient capacity in the
POTW treatment plant to treat the wastewater properly, the application
shall be denied Sewer line and POTW treatment plant current use shall
be defined as the present use and the unutilized use which has been
committed, by resolution, to other users by the Town Board.
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 Jefferson County Health Department, in accordance with § 174-26. 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 Town expenses incidental thereto. Each street lateral shall be installed and inspected pursuant to Article VI, Building Laterals, Street Laterals Connections, and Fees, and inspection fees shall be paid by the applicant prior to initiating construction. Design and installation of sewers shall be as specified in § 174-30, 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 with the approved plans and specifications. The sewer, as constructed, must pass the infiltration test (or the exfiltration test, with prior approval), required in § 174-32, 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.
All costs and expenses incident to the installation and connection
of the building sewer shall be borne by the owner. The owner shall
indemnify the Town from any loss or damage that may directly or indirectly
be occasioned by the installation of the building sewer.
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 § 174-26, and shall be clearly shown and detailed on the plans and specifications submitted for approval. Force main details are covered in § 174-33. When requested, the applicant shall submit, to the Superintendent and to the Jefferson County Health Department, 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.
A.
Sewer pipe material shall be:
(1)
Polyvinyl chloride (PVC) pipe - heavy wall.
(a)
Pipe shall be made from Class 12454-B materials or better in
accordance with ANSI/ASTM Specification D-1784.
(b)
Pipe and accessories shall conform to the requirements of the
following, with a minimum pipe stiffness of 46 PSI at a maximum deflection
of 5%.
ANSI/ASTM
|
D 3034
|
(4 inches to 15 inches)
|
ASTM
|
F 679 Type I
|
(18 inches to 27 inches)
|
(2)
Other pipe materials.
(a)
Other pipe materials require prior written approval of the Superintendent
before being installed.
(b)
The minimum internal pipe diameter shall be eight inches for
gravity sewers and four inches for low pressure sewers.
(c)
Joints for the selected pipe shall be designed and manufactured
such that "O" ring gaskets of the "snap-on" type are used.
(d)
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 § 174-32 are met.
(e)
Joint preparation and assembly shall be in accordance with the
manufacturer's recommendations.
B.
Safety and load factors.
(2)
Utilizing the foregoing information, design shall be made as outlined
in Chapter IX of the Water Pollution Control Federation Manual of
Practice No. 9, latest edition, "Design and Construction of Sanitary
and Storm Sewers," and the pipe shall have sufficient structural strength
to support all loads to be placed on the pipe, with a safety factor
as specified above.
(3)
PVC pipe shall not be encased in concrete due to their different
coefficients of linear thermal expansion.
C.
Sewer pipe installation.
(1)
Local utilities shall be contacted to verify construction plans and
to make arrangements to disconnect all utility services, where required
to undertake the construction work. The utility services shall later
be reconnected. The work shall be scheduled so that there is minimum
inconvenience to local residents. Residents shall be provided proper
and timely notice regarding disconnection of utilities.
(2)
The construction right-of-way shall be cleared only to the extent
needed for construction. Clearing consists of removal of trees which
interfere with construction, removal of underbrush, logs, and stumps,
and other organic matter, removal of refuse, garbage, and trash, removal
of ice and snow, and removal of telephone and power poles, and posts.
Any tree which will not hinder construction shall not be removed,
and shall be protected from damage by any construction equipment.
Debris shall not be burned, but hauled for disposal in an approved
manner.
(3)
The public shall be protected from personal and property damage as
a result of the construction work.
(4)
Traffic shall be maintained at all times in accordance with applicable
highway permits. Where no highway permits are required, at least 1/2
of a street shall be kept open for traffic flow.
(5)
Erosion control shall be performed throughout the project to minimize
the erosion of soils onto lands or into waters adjacent to or affected
by the work. Erosion control can be effected by limiting the amount
of clearing and grubbing prior to trenching, proper scheduling of
the pipe installation work, minimizing time of open trench, prompt
grading and seeding, and filtration of drainage.
(6)
The trench shall be excavated only wide enough for proper installation
of the sewer pipe, manhole, and appurtenances. Allowances may be made
for sheeting, de-watering, and other similar actions to complete the
work. Roads, sidewalks, and curbs shall be cut, by sawing or by other
methods as approved by the Superintendent, before trench excavation
is initiated.
(7)
Under ordinary conditions, excavation shall be by open cut from the
ground surface. However, tunnelling or boring under structures other
than buildings may be permitted. Such structures include crosswalks,
curbs, gutters, pavements, trees, driveways, and railroad tracks.
(8)
Open trenches shall be protected at all hours of the day with barricades,
as required.
(9)
Trenches shall not be open for more than 30 feet in advance of pipe
installation nor left unfilled for more than 30 feet in the rear of
the installed pipe, when the work is in progress, without permission
of the Superintendent. When work is not in progress, including over
night, weekends, and holidays, the trench shall be backfilled to ground
surface.
(10)
The trench shall be excavated approximately six inches deeper
than the final pipe grade. When unsuitable soils are encountered,
these shall be excavated to a maximum depth of 2 1/2 feet below
the final pipe invert grade and replaced with select materials.
(11)
Ledge rock, boulders, and large stones shall be removed from
the trench sides and bottom. The trench shall be over-excavated at
least 12 inches for five feet, at the transition from rock bottom
to earth bottom, centered on the transition.
(12)
Maintenance of grade, elevation, and alignment shall be done
by some suitable method or combination of methods.
(13)
No structure shall be undercut unless specifically approved
by the Superintendent.
(14)
Proper devices shall be provided, and maintained operational
at all times, to remove all water from the trench as it enters. At
no time shall the sewer line be used for removal of water from the
trench.
(15)
To protect workers and to prevent caving, shoring and sheeting
shall be used, as needed. Caving shall not be used to backfill the
trench. Sheeting shall not be removed but cut off no lower than one
foot above the pipe crown nor no higher than one foot below final
grade, and left in the trench, during backfill operations.
(16)
The pipe barrel shall be supported, along its entire length,
on a minimum of six inches of crusher run max. 1/2 inch stone free
of organic material. This foundation shall be firmly tamped in the
excavation.
(17)
Bell holes shall be hand excavated, as appropriate.
(18)
Pipe shall be laid from low elevation to high elevation. The
pipe bell shall be up-gradient; the pipe spigot shall be down-gradient.
(19)
Joint preparation and assembly shall be in accordance with the
manufacturer's written instructions.
(20)
The grade and alignment shall be checked and made correct. The
pipe shall be in straight alignment. Any negotiation of curves shall
be at manholes, except when site conditions require alternative pipe
laying procedures. These alternative procedures, including bending
the pipe barrel, deflecting the joint, and using special fittings,
shall require prior written approval of the plans and also written
confirmation approval of need by the Superintendent after examination
of the site conditions.
(21)
When a smaller sewer joins a larger one the invert of the larger
sewer shall be lowered sufficiently to maintain the same hydraulic
gradient. An approximate method which may be used for securing this
result is to place the 0.8 depth of both sewers at the same elevation.
(22)
Crushed stone shall be placed over the laid pipe to a depth
of at least six inches. The embedment of thermoplastic pipe shall
be in accordance with ASTM D2321 using Class 1A or 1B backfill materials.
Care shall be exercised so that stone is packed under the pipe haunches.
Care shall be exercised so that the pipe is not moved during placement
of the crushed stone.
(23)
The migration of fines from surrounding backfill or native soils
shall be restricted by gradation of embedment materials or by use
of suitable filter fabric.
(24)
The remaining portion of the trench above the pipe embedment
shall be backfilled in foot lifts which shall be firmly compacted.
Compaction near/under roadways, driveways, sidewalks, and other structures
shall be to 95% of the maximum moisture-density relationship, as determined
by ASTM Specification D 698, Method D. Ice, snow, or frozen material
shall not be used for backfill.
D.
Cleanout installation.
A.
Design of all manholes shall be submitted to the Superintendent and
shall receive approval prior to placement.
B.
Manholes shall be placed where there is a change in slope or alignment,
and at intervals not exceeding 400 linear feet except as authorized
by the Superintendent.
C.
Manhole bases shall be constructed or placed on a minimum of six
inches of crusher run maximum 1/2 inch stone free of organic materials.
D.
Manhole bases shall be constructed of 4,000 psi (28 day) concrete
eight inches thick, or shall be pre-cast bases properly bedded in
the excavation. Field constructed bases shall be monolithic, properly
reinforced, and extend at least six inches beyond the outside walls
of lower manhole sections. Pre-cast manhole bases shall extend at
least six inches beyond the outside walls of lower manhole sections.
E.
Manholes shall be constructed using precast minimum four foot diameter
concrete manhole barrel sections, and an eccentric top section, conforming
to ASTM Specification C-478, with the following exceptions on wall
thickness:
Manhole Diameter
(feet)
|
Wall Thickness
(inches)
|
---|---|
4
|
5
|
5
|
6
|
6
|
7
|
6 1/2
|
7 1/2
|
7
|
8
|
8
|
9
|
F.
All joints between sections shall be sealed with an "O" ring rubber
gasket, meeting the same specifications as pipe joint gaskets, or
butyl joint sealant completely filling the joint.
G.
All joints shall be sealed against infiltration. All metal parts
shall be thickly coated with bitumastic or elastomeric compound to
prevent corrosion.
H.
No steps or ladder rungs shall be installed in the inside or outside
manhole walls at any time.
I.
No holes shall be cut into the manhole sections closer than six inches
from joint surfaces.
J.
Manholes which extend above grade shall not have an eccentric top
section. The top plate shall be large enough to accommodate the cover
lifting device and the cover.
K.
The elevation of the top section shall be such that the cover frame
top elevation is 0.5 foot above the one-hundred-year flood elevation
(in a field), 0.5 foot above a lawn elevation, or at finished road
or sidewalk grade.
L.
When located in a travelled area (road or sidewalk), the manhole
frame and cover shall be heavy duty cast iron. When located in a lawn
or in a field, the manhole frame and cover may be light duty cast
iron. The cover shall be 36 inches, minimum, in diameter. The minimum
combined weight of the heavy duty frame and thirty-six inch cover
shall be 735 +/- 5% lbs. The minimum combined weight of the light
duty frame and thirty-six inch cover shall be 420 +/- 5% lbs. The
mating surfaces shall be machined, and painted with tar pitch varnish.
The cover shall not rock in the frame. Infiltration between the cover
and frame shall be prevented by proper design and painting. Covers
shall have "Sanitary Sewer" cast into them. Covers shall have lifting
holes suitable for any lifting/jacking device. The lifting holes shall
be designed so that infiltration is prevented.
M.
A drop of at least 0.1 foot shall be provided between incoming and
outgoing sewers on all junction manholes and on manholes with bends
greater than 45°.
N.
Inverts and shelves/benches shall be placed after testing the manholes
and sewers.
O.
Benches shall be level and slope to the flow channel at about one
inch per foot.
P.
The minimum depth of the flow channel shall be the nominal diameter
of the smaller pipe. The channel shall have a steel trowel finish.
The flow channel shall have a smooth curvature from inlet to outlet.
Q.
Manhole frames, installed at grade, shall be set in a full bed of
mortar with no less than two nor more than four courses of brick underneath
to allow for later elevation adjustment. In lieu of brick, grade rings
may be used for elevation adjustment. Grade rings shall not exceed
six inches in depth. The total number of grade rings shall not exceed
12 inches in height; however, in no event shall more than three grade
rings be used.
R.
Manholes which extend above grade, shall have the frames cast into
the manhole top plate. The top plate shall be securely anchored to
the manhole barrel, by a minimum of six 1/2 inch corrosion resistant
anchor bolts, to prevent overturning when the cover is removed. The
anchor bolts shall be electrically isolated from the manhole frame
and cover.
S.
Internal drop pipes and fittings shall be PVC plastic sewer pipe
in compliance with ASTM D2241. Corrosion resistant anchors shall be
used to attach the drop pipe to the inside surface of the manhole
barrel.
A.
Infiltration/exfiltration testing. 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 Superintendent. 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 § 174-31F and/or G 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.
B.
Test section. 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 re-tested.
C.
Test period. The test period, during which the test measurements
are taken, shall not be less than two hours.
D.
Pipe lamping. Prior to testing, the section shall be lamped. Any
length of pipe out of straight alignment shall be re-aligned.
E.
Deflection testing. 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.
F.
Low pressure air testing alternative.
(1)
In lieu of hydrostatic testing (exfiltration or infiltration), low
pressure air testing may be employed. Low pressure air tests shall
conform to ASTM Specification C 828. All sections to be tested shall
be cleaned and flushed, and shall have been backfilled, prior to testing.
Air shall be added until the internal pressure of the test section
is raised to approximately 4.0 PSIG. The air pressure test shall be
based on the time, measured in seconds, for the air pressure to drop
from 3.5 PSIG to 2.5 PSIG.
(2)
Acceptance is based on limits tabulated in the "Specification Time
Required for a 1.0 PSIG Pressure Drop" in the Uni-Bell PVC Pipe Association
"Recommended Practice For Low-Pressure Air Testing of Installed Sewer
Pipe."
(3)
Before pressure is applied to the line all connections shall be firmly
plugged. Before the test period starts, the air shall be given sufficient
time to cool to ambient temperature in the test section.
(4)
If the test section is below groundwater, the test pressure shall
be increased by an amount sufficient to compensate for groundwater
hydrostatic pressure, however, the test pressure shall not exceed
10 PSI, or a lower pressure as required by the Superintendent.
(5)
The pressure test gauge shall have been recently calibrated, and
a copy of the calibration results shall be made available to the Superintendent
prior to testing.
G.
Vacuum testing alternative.
(1)
In lieu of hydrostatic testing (exfiltration or infiltration), vacuum
testing may be employed for testing of sewer lines and manholes. Sewer
lines and manholes shall be tested separately. All sewer lines to
be tested shall be cleaned and flushed, and shall have been backfilled,
prior to testing. The vacuum test shall be based on the time, measured
in seconds, for the vacuum to decrease from 10 inches of mercury to
nine inches of mercury for manholes, and from seven inches of mercury
to six inches of mercury for sewers.
(2)
Acceptance of manholes is based on the following:
Manhole Depth
(feet)
|
Manhole Diameter
(feet)
|
Time to Drop 1" Hg (10" to 9")
(seconds)
|
---|---|---|
10 or less
|
4
|
120
|
10 to 15
|
4
|
150
|
15 to 25
|
4
|
180
|
(3)
If the test on the manhole fails (the time is less than that tabulated
above), necessary repairs shall be made and the vacuum test repeated,
until the manhole passes the test.
(4)
Acceptance of sewers (seven inches Hg to six inches Hg) is based
on the time tabulated in the "Specification Time Required for a 0.5
PSIG Pressure Drop" in the Uni-Bell PVC Pipe Association "Recommended
Practice For Low-Pressure Air Testing of Installed Sewer Pipe."
(5)
The vacuum test gauge shall have been recently calibrated, and a
copy of the calibration results shall be made available to the Superintendent
prior to testing.
A.
Design requirements. Force mains serving sewage lifting devices, such as grinder pumps and pump stations, shall be designed in accordance with § 174-26. Additional design requirements are:
(1)
Force main pipe material shall be:
(a)
Polyvinyl chloride (PVC) plastic 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.
(b)
Other pipe materials. Other pipe materials require prior written
approval of the Superintendent and the Town Board before being installed.
(3)
Joint preparation and assembly shall be in accordance with the manufacturer's
written instructions.
(4)
Anchorages, concrete blocking, and/or mechanical restraint shall
be provided when there is a change of direction of 7 1/2°
or greater.
(5)
Drain valves shall be placed at low points.
(6)
Automatic air relief valves shall be placed at high points and at
400 feet intervals, on level force main runs.
(7)
Air relief and drain valves shall be suitably protected from freezing.
(8)
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.
(9)
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
90° 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.
B.
Force main testing. All force mains shall be subjected to hydrostatic
pressure of 150% of the normal operating pressure. The duration of
the test, at pressure, shall be at least two hours. Before conducting
the test, the pipe shall be filled with water and all air shall be
expelled. During the test, water shall be added, as needed, to maintain
the test pressure. The amount of water added shall be recorded so
as to calculate leakage. Leakage shall not exceed 25 gallons per day
per mile per inch nominal pipe diameter. During the test, the owner
and the Superintendent shall walk the route of the force main and
examine the exposed pipe and the ground covering any backfilled pipe
to discover leaks. Leakage in excess of that specified above shall
be corrected with new material at the owner's expense and the
test repeated. Any observed leaks shall be repaired at the owner's
expense. Each test section length shall be as approved by the Superintendent,
but in no event longer than 1,000 feet.
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 Town of Wilna Sewer District, and shall thereafter
be operated and maintained by the Town of Wilna Sewer District. No
sanitary sewer shall be accepted by the Town 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.
A.
All contractors engaged in connecting house laterals with sanitary
sewers, who perform any work within the right-of-way of any highway,
shall file a bond in the amount of $5,000 with the Town Clerk to indemnify
the Town against loss, cost, damage or expense sustained or recovered
on account of any negligence, omission or act of the applicant for
such a permit, or any of his, or their agents arising or resulting
directly or indirectly by reason of such permit or consent, or of
any act, construction or excavation done, made or permitted under
authority of such permit or consent. All bonds shall contain a clause
that permits given by the Town Board may be revoked at any time for
just cause.
B.
Before commencing work, the above contractor shall file insurance
certificates with the Town Clerk for the following:
(1)
Workman's compensation and employer's liability insurance
as required by the laws of the state covering the contractor;
(2)
Personal injury liability having limits of not less than $1,000,000
each occurrence and $1,000,000 aggregate (completed operations/products,
personal injury);
(3)
Property damage liability having limits of not less than $500,000
for all damages arising during the life of the contract; and shall
include, but not be limited to, the following designated hazards:
(5)
Business excess liability insurance in the amount of $2,000,000.
(6)
All insurance policies must provide for five business days'
notice to the Town of Wilna before cancellation and must cover all
liabilities of the Town of Wilna and be in a form approved by the
Town Board and be in a satisfactory form approved by the Board.
(7)
The minimum insurance limits stated above shall be subject to periodic
review by the Town Board and adjustments made, by resolution, as appropriate.
C.
Where it is necessary to enter upon or excavate any highway or cut
any pavement, sidewalk or curbing, permission must be obtained from
the Town Superintendent if a Town highway is involved, from the County
Department of Public Works if a county highway is involved, and/or
the New York State Department of Transportation if a state highway
is involved.
D.
The minimum insurance limits above shall be as established by the
Town Board and shall be subject to periodic review and adjustment,
as appropriate, by the Town Board.