A.
New sanitary sewers and all extensions to sanitary sewers owned and
operated by the Town of Elma 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 Erie 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 of Elma 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 Erie County Health Department, in accordance with § 115-28. 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 Town of Elma 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 § 115-31 through 115-34, 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 §§ 115-36 through 115-42, 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 of Elma Board until such construction inspections have been made so as to assure the Town of Elma 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 of Elma 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 § 115-28, and shall be clearly shown and detailed on the plans and specifications submitted for approval. Force main details are covered in §§ 115-43 through 115-44. When requested, the applicant shall submit, to the Superintendent and to the Erie 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 materials can be found in the sewer specifications document.
B.
The minimum internal pipe diameter shall be eight inches for gravity
sewers and three 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.
E.
Joint preparation and assembly shall be in accordance with the manufacturer's
recommendations.
B.
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.
C.
PVC pipe shall not be encased in concrete due to the different coefficients
of linear thermal expansion.
A.
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.
B.
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.
C.
The public shall be protected from personal and property damage as
a result of the construction work.
D.
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.
E.
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.
F.
The trench shall be excavated only wide enough for proper installation
of the sewer pipe, manhole, and appurtenances. Allowances may be made
for sheeting, dewatering, 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.
G.
Under ordinary conditions, excavation shall be by open cut from the
ground surface. However, tunneling or boring under structures other
than buildings may be permitted. Such structures include crosswalks,
curbs, gutters, pavements, trees, driveways, and railroad tracks.
H.
Open trenches shall be protected at all hours of the day with barricades,
as required.
I.
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 overnight,
weekends, and holidays, the trench shall be backfilled to ground surface.
J.
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.
K.
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.
L.
Maintenance of grade, elevation, and alignment shall be done by some
suitable method or combination of methods.
M.
No structure shall be undercut unless specifically approved by the
Superintendent.
N.
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.
O.
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.
P.
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.
Q.
Bell holes shall be hand excavated, as appropriate.
R.
Pipe shall be laid from low elevation to high elevation. The pipe
bell shall be up-gradient; the pipe spigot shall be down-gradient.
S.
Joint preparation and assembly shall be in accordance with the manufacturer's
written instructions.
T.
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.
U.
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.
V.
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.
W.
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.
X.
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.
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 max 1/2 inch stone free of organic materials.
D.
Manhole bases shall be constructed of 4,000 psi (twenty-eight-day)
concrete eight inches thick, or shall be precast 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. Precast manhole bases shall extend at least
six inches beyond the outside walls of lower manhole sections.
E.
Manhole construction.
(1)
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
|
(2)
All sections shall be cast solid, without lifting holes.
(3)
Flat top slabs shall be a minimum of eight inches thick and shall
be capable of supporting a H-20 loading.
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 traveled 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% pounds. The minimum combined weight of the light-duty frame
and thirty-six-inch cover shall be 420 +/- 5% pounds. 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 one-half-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.
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 Town of Elma. The exfiltration 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 infiltration 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 § 115-41 and/or § 115-42 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.
A.
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.
B.
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."
C.
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.
D.
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.
E.
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.
A.
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.
B.
Acceptance of manholes is based on the following:
|
Manhole Depth
(feet)
|
Manhole Diameter
(feet)
|
Time to Drop 1 Inch of Hg
(10 inches to 9 inches)
(seconds)
| |
|---|---|---|---|
|
10 or less
|
4
|
120
| |
|
10 to 15
|
4
|
150
| |
|
15 to 25
|
4
|
180
|
|
NOTE: For five-foot diameter manholes, add 30 seconds to the
times above.
|
|
NOTE: For six-foot diameter manholes, add 60 seconds to the
times above.
|
C.
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.
D.
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."
E.
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.
Force mains serving sewage lifting devices, such as grinder pumps and pump stations, shall be designed in accordance with § 115-28. Additional design requirements are:
A.
Force main pipe material shall be as per the specifications document.
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 feet 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
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.
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 of Elma Board, shall
become the property of the Town of Elma, and shall thereafter be operated
and maintained by the Town of Elma. No sanitary sewer shall be accepted
by the Town of Elma 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 of Elma, 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 of Elma Board, secured by a surety bond or such other security
as the Town of Elma 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 of Elma Clerk
to indemnify the Town of Elma 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 of Elma Board may
be revoked at any time for just cause.
B.
Before commencing work, the above contractor shall file insurance
certificates with the Town of Elma Clerk for the following:
(1)
Workmen'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 $500,000
each occurrence and $500,000 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 Elma before cancellation and must cover all liabilities
of the Town of Elma and be in a form approved by the Town of Elma
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 of Elma 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 Superintendent of Highways if a Town of Elma 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 of Elma Board and shall be subject to periodic review and adjustment,
as appropriate, by the Town of Elma Board.
