[HISTORY: Prepared by NIRA Consulting Engineers, Inc. as
revised April 2007. Amendments noted where applicable.]
A.
These specifications have been developed as a guide to assist developers,
designers and contractors involved in planning, designing and constructing
sanitary sewerage facilities under the jurisdiction of the Collier
Township Municipal Authority ("Authority"). It should be understood
that these specifications are general in nature and are not intended
to address all conditions or needs of a particular project. Special
circumstances which are peculiar to individual projects may require
special design considerations. Developers and designers of proposed
sanitary sewerage facilities are encouraged to consult with the Authority
and/or its authorized representatives regarding specific problems
or unusual circumstances which may arise in the planning, design or
construction of such facilities.
B.
The work covered by these specifications consists of furnishing all
labor, equipment, and materials, including all pipe, materials for
joint connection, manholes, service lines and completing all construction
as shown on the drawings or as specified herein.
Pipes and joints for the various types of sewer lines shall
be of the materials indicated herein. Pipe shall be laid true to the
grades shown on the drawings or as directed by the Authority or the
Authority's authorized representative. All sewer mains shall be installed
by utilizing laser equipment designed for the intended purpose. Laser
equipment shall be checked for accuracy of grade and calibrated as
required by the Authority or the Authority's authorized representative.
Each section of pipe shall rest upon the pipe bed for the full length
of its barrel, with recesses to accommodate bells and joints. Any
pipe that has its grade or joint disturbed after laying shall be taken
up and relaid. The interior of all pipe shall be thoroughly cleaned
of all foreign matter before being lowered into the trench and shall
be kept clean during laying operations by means of plugs or other
approved methods. Any section of pipe already laid and found to be
defective shall be removed and replaced with new pipe.
To ensure that the specified products are furnished and installed,
submittals, including manufacturer's certificates, shop drawings,
brochures, product samples and catalog cuts, for all products and
materials to be used in connection with the project shall be submitted
to the Authority or the Authority's authorized representative. All
submittals shall be submitted in quadruplicate and shall be submitted
sufficiently in advance of the purchase of such materials to permit
review of the submittals by the Authority or the Authority's authorized
representative. No substitution of materials or equipment shall be
permitted without written approval of the Authority or the Authority's
authorized representative.
A.
The side walls of the trench shall be kept as nearly vertical as
possible and shall be properly shored and braced. Trenches shall be
excavated true to line and grade so that a clear space of not less
than four inches and not more than eight inches is provided on either
side of the barrel of the pipe.
B.
All pipe trench excavation shall be made to a minimum depth of four
inches beneath the pipe. The pipe shall then be bedded in crushed
stone or cracked gravel bedding material in accordance with the requirements
for Class B, First Class AASHTO #57 bedding material in accordance
with ASTM Designation C-12, latest edition, and conforming with the
applicable standard detail drawings.[1]
[1]
Editor's Note: See the detail drawings included as an attachment to this chapter.
C.
Where rock excavation is encountered, the rock shall be excavated
a minimum overdepth of six inches below the trench depths specified.
The overdepth rock excavation and all excessive trench excavation
shall be backfilled with Class B, First Class AASHTO #57 bedding material
in accordance with ASTM Designation C-12, latest edition. All aggregate
materials shall meet Pennsylvania Department of Transportation specifications
Publication 408, latest edition.
D.
Where quicksand, muck or other such conditions exist, which result
in an unstable trench bottom, tongue-and-groove sheet piling, timber
piles and/or over excavation and backfilling with selected borrow
material may be required. The type and extent of methods employed
to stabilize the trench bottom shall be approved by the Authority
or the Authority's authorized representative.
E.
All groundwater which may be found in the trenches and any water
which may get into them from any cause whatsoever shall be pumped
or bailed out so that the trench shall be dry during the pipe-laying
period. No water shall be permitted to reach the joints or run through
the pipe. All water pumped from the trenches shall be disposed of
in a satisfactory manner.
A.
Polyvinyl chloride (PVC). PVC pipe and fittings shall be bell-and-spigot
type, free from defects, and shall conform in all respects to ASTM
Designation D-3034-SDR-35.
B.
Ductile iron pipe. Ductile iron pipe shall be AWWA C151 special thickness
Class 52, bell-and-spigot type, free from defects, and shall conform
in all respects to AWWA C150 and C151. The inside of the pipe and
fittings shall be coated with Protecto 401 ceramic epoxy lining at
a nominal thickness of 40 mils or approved equal. The pipe and fittings
shall be asphalt-coated on the outside in accordance with AWWA C104.
All ductile iron pipe shall be not less than special thickness Class
52, except where a higher pressure class may be required by the Authority
or the Authority's authorized representative.
C.
Steel casing pipe. Steel casing pipe shall be welded steel pipe,
manufactured and tested in accordance with ASTM A-53, Grade B, with
a minimum yield strength of 35,000 psl. The pipe shall be new, visibly
sound and round. Minimum casing wall thickness shall be as follows:
|
Nominal Diameter of Casing Pipe
(inches)
|
Wall Thickness
(inches)
|
|---|---|
|
Under 14
|
0.251
|
|
14 and 16
|
0.282
|
|
18
|
0.313
|
|
20
|
0.344
|
|
22
|
0.375
|
|
24
|
0.407
|
|
26
|
0.438
|
|
28 and 30
|
0.469
|
|
32
|
0.501
|
|
34 and 36
|
0.532
|
Where the Authority or its authorized representative requires
the use of ductile iron pipe for reasons of depth of cover, high external
loading, steep slopes or other physical circumstances, the exterior
of the ductile iron pipe and fittings shall be encased in polyethylene
film wrap with a minimum nominal thickness of 8 mils or approved equal
in accordance with ANSI/ASTM D-1248 and with AWWA Standard C105, Polyethylene
Encasement for Ductile Iron Piping for Water and Other Liquids.
Where sewer lines are installed on steep slopes, the Authority
or the Authority's authorized representative may require, in addition
to pipe anchors, the use of joint restraint mechanisms which may include
but are not limited to approved field locking gaskets for ductile
iron pipe or bell joint restrainers for PVC pipe.
Where sewer lines are installed by boring, the sewer pipe shall
be placed in a steel casing pipe and shall be supported by casing
spacers constructed of high molecular weight polymer runners secured
to a stainless steel shell, as manufactured by Cascade Water Works
Mfg. Co. of Yorkville, IL. Not less than three spacers shall be used
on each pipe length.
Casing pipe end seals of the required size shall consist of
a rubber seal and two T-304 stainless steel bands, as manufactured
by Cascade Water Works Mfg. Co. of Yorkville, IL.
A.
All manholes sections shall be reinforced precast concrete and shall
conform to ASTM Designation C-478, latest revision. Manhole joints
shall have two three-quarter-inch-wide rings of "Kent-Seal" No. 2
or conseal CS-202 flexible BUTYL sealant to ensure water tightness
conforming to ASTM Designation C-361 and C-443, latest revision, AASHTO
M-198. Manholes shall provide a watertight pipe to manhole connection.
The pipe to manhole connection shall consist of either:
(1)
A standard rubber connector gasket integrally cast within the
manhole wall. Use A-LOK brand X-CEL, or approved equal, conforming
to all material and test requirements outlined in ASTM C-923
(2)
An integrally cast boot complete with stainless steel banding
and clamp. Use A-LOK brand Z-LOK, or approved equal, conforming to
all material and test requirements outlined in ASTM C-923.
(3)
A positive seal gasket with expanded sleeve and stainless steel
banding and clamp. Use PSX Manhole Connector, or approved equal, conforming
to all material and testing requirements outlined in ASTM C-923.
B.
All manholes shall be watertight and as infiltration-proof as possible.
Openings through the manhole walls shall be plugged with Thorite General
Purpose Mortar with Acryl 160 Additive or approved equal. Any noticeable
groundwater leakage into the manhole shall be repaired in a manner
satisfactory to the Authority or the Authority's authorized representative.
C.
Manhole flow line channels shall be molded in the floor of the precast
concrete base and shall be finished smooth sloping from the influent
pipe invert to the effluent pipe invert. The elevation difference
between manhole pipe inverts shall conform to the approved design
profiles; however, the minimum elevation difference between influent
and effluent pipe inverts shall never be less than 0.20 vertical foot.
Pipes projecting into manholes shall not project more than two inches
beyond the interior wall surface of the manhole. Concrete used for
this purpose shall meet the Pennsylvania Department of Transportation
Form 408 specifications for Class A concrete.
D.
Xypex. Manhole concrete shall contain Xypex Admix C-1000 at a rate
of 2% to 3% by weight of cement. The Xypex shall be blended into the
concrete at the time of batching. Xypex Admix C-2000 at a rate of
2% by weight of cement may be required where extended retardation
is desired.
Manhole steps shall be placed on not less than twelve-inch centers,
but not more than sixteen-inch centers. The steps shall be placed
along the straight side of the manhole and shall be properly aligned.
The steps shall be reinforced polypropylene plastic, as manufactured
by M.A. Industries, Inc., Type PS-4 or equal, and shall conform in
all respects to ASTM 2146-68, Type II, Grade 49108. The steel shall
be a deformed three-eighths-inch reinforced rod, Grade 60, conforming
to ASTM A-615.
A.
All castings for manhole heads, covers, and other purposes must be
tough gray iron, free from cracks, holes, swells, and cold shuts.
B.
The quality shall be such that a blow from the hammer will produce
an indentation on a rectangular edge of the casting without flaking
the metal. All manhole castings shall be made accurately to the pattern
and to the dimensions shown on the drawings and shall be planned where
marked or where otherwise necessary to secure perfectly flat and true
surfaces.
C.
Allowances shall be made in the patterns so that the thickness shall
not be reduced. All lids which "rock" and do not lie solid after construction
is finished will be condemned and must be replaced by perfect lids.
No plugging, burning in, or filling will be allowed. Covers must fit
the frames in any position. All manhole covers shall be marked as
shown on the applicable standard detail drawing.[1]
[1]
Editor's Note: See the detail drawings included as an attachment to this chapter.
D.
Frames shall be bolted down to the top section of the manhole and
shall have two rows of three-quarter-inch-wide "KENT-SEAL" No. 2 or
"Conseal" CS-202 flexible BUTYL sealant placed between casting and
manhole before securing.
Where manholes are located in paved areas or for any reason
may be subject to the inflow of surface water, a watertight manhole
insert shall be provided and installed to prevent inflow of such surface
water into the manhole through the manhole cover. Manhole inserts
shall be the "Rainstopper" manhole insert, as manufactured by Southwestern
Packing & Seals, Inc., Shreveport, LA, or equal.
Install underground early warning detection tape as indicated
on the detail drawing.[1] Tape shall be installed above all sewer lines installed
and as shown on the applicable standard detail. The tape shall be
equal to Detectable Underground Marking Tapes, as manufactured by
Pro-Line Safety Products. Tape shall be six inches wide, green, and
shall state "Caution Sanitary Sewer Line Buried Below."
[1]
Editor's Note: See the detail drawings included as an attachment to this chapter.
Cement concrete and ready-mixed cement concrete shall be Class
A conforming to Section 704 of the Pennsylvania Department of Transportation
specifications, Form 408.
A.
Pipeline stream crossings shall be constructed in accordance with
the following specifications and with all Pennsylvania DEP and Allegheny
County Conservation District requirements.
B.
Concrete shall encase the sewer pipe a minimum of five feet beyond
the stream edges. Provide a minimum of six inches of PennDOT Class
A cement concrete around the pipe O.D. and reinforce as shown on the
standard detail.[1] Backfill with a minimum size of PennDOT R-3 crushed limestone
to the level of the stream bed between the limits of the stream crossing.
[1]
Editor's Note: See the detail drawings included as an attachment to this chapter.
A.
Caution in all cases of earth filling and backfilling shall be exercised
to ensure that it is not done prematurely and that no pressure against
which the construction has not been designed to withstand is exerted
thereby. Any movement of the structure incident to neglect or failure
in such exercise of caution shall be promptly and fully corrected.
B.
The area to be backfilled shall be cleared of all trash and debris
prior to backfilling. Material for backfilling shall consist of the
excavation or borrow of sand, gravel, or other materials approved
by the Authority or the Authority's authorized representative, and
shall be free of trash, lumber and other debris. Backfill shall be
placed in horizontal layers not in excess of six inches in thickness,
properly moistened to approximate optimum requirements, and each layer
shall be compacted by vibrator tampers, machine tampers, or other
suitable equipment to not less than 95% of the determined dry weight
density.
C.
Backfill to 12 inches above the crown of the pipe shall be with AASHTO
#57 coarse aggregate hand placed and carefully compacted with hand-operated
mechanical tampers in layers of suitable thickness to provide specified
compaction around and under the haunches of the pipe. All aggregate
materials shall meet Pennsylvania Department of Transportation specifications
Publication 408, latest edition.
D.
All pipe trenches crossing roadways, driveways, etc. shall be backfilled
with PennDot #2A select granular aggregate materials from the top
of the pipe bedding up to the roadway or driveway pavement structure.
Backfill compaction shall be performed in accordance with this section.
E.
Puddling will not be permitted.
A.
Precast manholes. New pipe connections to existing precast manholes
shall be made by core boring a neat circular hole in the wall of the
manhole. The proper-size PSX manhole connector as manufactured by
Press-Seal Gasket Corporation, or approved equal, shall be installed.
A length of sewer pipe shall be inserted through the connector and,
when directed by the Engineer, the area around the pipe shall be filled
with Thorite General Purpose Mortar with Acryl 60 additive, or approved
equal. The invert of the manhole shall be shaped to accommodate the
invert of the pipe with Thorite General Purpose Mortar with Acryl
60 additive or equal.
B.
Brick manholes.
(1)
A minimal amount of brick shall be removed by core boring a
hole in the manhole wall. All voids in the manhole wall shall be filled
with Thorite General Purpose Mortar with Acryl 60 additive or approved
equal. The manhole wall must be clean and smooth prior to installation
of pipe to manhole adaptor. The proper-size sanded manhole adaptor
as manufactured by GPK Products, Inc. shall be installed. The area
around the adaptor shall be filled with Thorite General Purpose Mortar
with Acryl 60 or approved equal. The invert of the manhole shall be
shaped to accommodate the invert of the pipe with Thorite General
Purpose Mortar with Acryl 60 additive or equal.
(2)
Drop manhole connections to existing manholes shall be constructed
as outlined above and as shown on the standard details.[1]
[1]
Editor's Note: See the detail drawings included as an attachment to this chapter.
The installation of drop manhole connections will only be allowed
when excavating to the depth required to install a conventional connection
is not practical. The Authority or Authority's representative shall
make this determination. When an inside drop manhole connection is
proposed, a sixty-inch-diameter manhole will be required for all new
sanitary sewer installations. (See standard detail for installation
requirements.[1]). An outside drop manhole connection will be allowed for
connections to existing manholes. (See standard detail for installation
requirements.)
[1]
Editor's Note: See the detail drawings included as an attachment to this chapter.
A.
Low-pressure air testing for leakage.
(1)
All sewer pipe shall be tested by means of a low-pressure air
test. The final air test shall not be made until all service laterals
have been installed up to the property line or edge of the easement,
as the case may be. All air testing shall be performed prior to any
permanent surface restoration.
(2)
The contractor shall plug and brace the ends of the sewer lines
being tested. At his option, the contractor may conduct an initial
air test of the sewer main line after densification of the backfill,
but prior to installation of the house laterals. Such preliminary
tests shall not constitute a final test.
(3)
The final leakage test shall be conducted in the following manner
and shall include both the sewer main line and laterals:
(a)
Add air slowly to the portion of the pipe installation under
test until the internal air pressure is raised to 5.0 psig.
(b)
After an internal pressure of 5.0 psig is obtained, allow at
least two minutes for air temperature to stabilize, adding only the
amount of air required to maintain 5.0 psig internal pressure.
(c)
After stabilization, the portion of the pipe installation under
test must maintain an internal pressure of 5.0 psig without loss for
a minimum period of five minutes.
(d)
If pressure loss occurs within the stated five-minute period,
the pipe section under test shall have failed to meet the requirements
of these specifications and the contractor shall make such repairs
as are necessary in order to meet these specifications.
(4)
The input air pressure shall not exceed 10 psig, utilizing a
regulator set to avoid over-pressurizing and damaging an otherwise
acceptable line.
(5)
The air testing equipment shall be approved by the Authority
or the Authority's authorized representative.
B.
Deflection test for PVC pipe. The installed sewer line shall meet
a deflection requirement of less than 5% by the use of a go/no-go
gauge pulled through the line. This test shall be performed three
months after installation. The go/no-go gauge shall be supplied by
the pipe manufacturer.
A.
All
new manholes shall be vacuum tested in accordance with the following
procedure:
(1)
Plug all pipe openings. Take care to securely brace the plugs and
pipe.
(2)
Inflate the compression band to effect a seal between the vacuum
base and the structure.
(3)
Connect the vacuum pump to the outlet port with the valve open.
(4)
Draw a vacuum to 10 inches of Hg. Close the valve.
(5)
Start the test and maintain for 60 seconds. Record the vacuum drop
during the test period.
(6)
If the vacuum drop is greater than 1.0 inch of Hg during the
test period, the manhole shall be repaired and retested. If a vacuum
drop of one inch of Hg does not occur during the test period, the
test shall be discontinued and the manhole will be accepted. If the
loss of vacuum exceeds 1.0 inch of Hg, repair leaks and retest.
B.
If a unit fails to meet a one-inch Hg drop in the specified time
after repair, the unit shall be subjected to the water exfiltration
test and repaired as necessary as directed by the Authority or the
Authority's authorized representative.
All ground surfaces disturbed while installing main line sewers
or lateral connections must be restored to a condition equal to or
better than the original surface condition.
A.
Topsoil furnished and placed.
(1)
Topsoil shall conform to Section 802 of the Pennsylvania Department
of Transportation specifications Form 408, latest edition.
(2)
Grade the areas to be covered by topsoil. Using acceptable methods,
loosen soil to a depth of 50 mm (two inches) before placing the topsoil.
Remove stones and other foreign material 50 mm (two inches) or larger
in any dimension. Remove and satisfactorily dispose of unsuitable
and surplus material.
(3)
Place topsoil on the prepared areas and, unless otherwise indicated,
spread and compact to a 100 mm (four-inch) uniform depth. Compact
with a roller having a mass (weight) not over 180 kg/m (120 pounds
per foot) width of roller or by other acceptable methods, as directed.
Remove overdepth topsoil, unless otherwise agreed upon in writing.
Do not place topsoil in a wet or frozen condition.
B.
Seeding and soil supplements.
(1)
Seeding and soil supplements shall conform to Section 804 of
the Pennsylvania Department of Transportation specifications Form
408, latest edition. Seed mixture shall be Formula "D" and/or Formula
"B" as directed by the Engineer. Formula "B" and/or Formula "D" shall
be sown at the rate of 21 pounds per 1,000 square yards. Lime shall
be applied at the rate of 800 pounds per 1,000 square yards and 10-20-20
commercial fertilizer at the rate of 192 pounds per 1,000 square yards.
(2)
Straw mulching shall be used in accordance with Section 805
of the Pennsylvania Department of Transportation specifications Form
408, latest edition.
(3)
The contractor will be responsible for securing a good catch
of seed and seedlings. Damages arising from improper adherence to
above conditions will be the responsibility of the contractor.
(4)
The contractor shall be responsible for a satisfactory growth
of the various seed formulas within the areas of restoration until
the expiration date of the maintenance bond.
C.
All pavements or cartway structures shall be restored to a depth
and to a condition equal to or better than the existing pavement structure.
All township, county and state roadway pavements disturbed by excavation
must be restored in accordance with the respective agency's standards.
A.
All materials and workmanship shall be subject to inspection, examination,
or test by the Authority or the Authority's authorized representative
at any and all times during manufacture or construction and at any
and all places where such manufacture or construction is carried on.
The Authority or the Authority's authorized representative shall have
the right to reject defective material and workmanship or require
its correction. Unacceptable workmanship shall be satisfactorily corrected.
Rejected material shall be promptly segregated and removed from the
construction site and replaced with material of specified quality.
B.
The Authority or the Authority's authorized representative and governmental
agencies with jurisdictional interests will have access to the work
at reasonable times for observation, inspection and testing. The contractor
shall provide proper and safe conditions for such access.
C.
The contractor shall give ample notice to the Authority or the Authority's
authorized representative before laying pipe so that an inspector
may make proper inspection. All pipe, before being lowered into the
trench, shall be inspected and both ends shall be cleaned.
D.
Before backfilling is begun, the contractor shall make tests as directed
by the Authority or the Authority's authorized representative in order
to ascertain if joints are tight. Leaking, poor or misaligned joints
shall be removed or repaired at once.
E.
Further
tests of the installation of sewers shall be made as follows:
(1)
After the mains have been laid and backfill placed to two feet
above the pipe, a light will be flashed between manholes or, if the
manhole has not yet been constructed, between the location of manholes,
by means of a flashlight or mirrored light to determine whether the
alignment of the main is true and whether any pipe has been displaced
subsequent to laying.
(2)
In case the alignment of the main is shown to be correct and
no other defects are disclosed, backfilling may be continued. In case
the test shows poor alignment of the main, misplaced pipe or other
defects, such defects shall be remedied by the contractor, to the
satisfaction of the Authority or the Authority's authorized representative,
before the work of backfilling proceeds.
A.
At the completion of the project and prior to the final acceptance
of any facilities by the Authority or the Authority's authorized representative,
accurate as-built drawings or electronic files, including plans and
profiles, shall be provided to the Authority or the Authority's authorized
representative. As-built drawings shall be reproducible Mylars or
measured horizontal angles and distances between the center line of
each successive manhole. All distances shall be recorded to the nearest
one hundredth of a foot. The size and type of pipe for each section
of the sewer line shall be clearly noted. The profiles shall include
each manhole top, flow line-in and flow line-out elevation. All elevations
shall be based on and tied to the North American Vertical Datum of
1983 — NAD 83 (1986).
B.
The as-built plans shall accurately demonstrate the location of all
wyes and service connections. The as-built stationing of all wyes
shall be recorded on the plan and may be included in a table of a
tabular format which identifies the location (left or right) and the
station of each wye, as measured from the center line of the sanitary
manhole located immediately downstream of the wye. The plans shall
also include the stationing and perpendicular offset, indicating whether
left or right, for the end of all service lines. The size, type and
depth at the end of each service line shall also be indicated. The
relative location, depth and approximate clearance of other underground
utilities and/or structures in close proximity to the sewer lines
and manholes shall be included on the as-built drawings. Any revisions
or additional information which may be required shall be subsequently
provided by the contractor.
