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Prior to construction of the sliplining repair, the Contractor shall submit
shop drawings, details, and descriptions to include construction methods and
equipment, process description, access locations, receiving manhole
locations, flow handling, bypass pumping, flow diversion, and or dewatering
methods and design calculations to assure that the work can be
accomplished as specified in this section. Pre- and post-construction video
documentation shall be provided to the Engineer as specified in pertinent
sections of the contract.

The Contractor shall submit for review shop drawings and/or descriptive
literature, providing the manufacturer's specific product data with
information on the new HDPE pipe physical and mechanical properties of
the pipe, pipe dimensions, joint configuration, and other details of pipe to
be furnished, design calculations showing structural adequacy of pipe
selected, allowable grout pressure, allowable pushing or pulling forces for
the pipe, method of pipe insertion, method of handling wastewater flows,
dewatering methods, bulkhead design and details, insertion pit or shaft
locations, method of support of excavation, and connection details to
transition systems for manholes and structures.

The Contractor shall submit cleaning methods and pre- and _post-
construction video documentation as specified herein.

1. The Contractor shall submit the particular method by which he
plans to maintain traffic, signing-schedule, access roads, and
locations of access shafts/pits and receiving pit locations to the
Owner for review and approval prior to commencement of
construction.

2. Prior to commencement of work, the Contractor shall submit a
detailed plan outlining how the Contractor intends to accomplish
the proposed pneumatically assisted sliplining work, including the
equipment set-up, schedule, and sequence of construction. The
Contractor shall notify all affected services prior to commencement
of work.

3. The Contractor shall submit written descriptions of the
construction method(s) and equipment to be used, and access shaft
sizes and locations required for equipment and material access.

4. The Contractor shall submit written descriptions of the
construction method(s) and equipment to be used to penetrate
blockages and/or partially collapsed sections of the host pipe. This
work shall be accomplished without excavation from the surface,

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unless written authorization is obtained from the Owner for surface
excavations to remove blockages.

5. Hours of operation, sequencing of work description, number of
shifts, number of crews, and expected time to complete the work
for the rehabilitation method proposed shall be described.

6. The Contractor shall describe any surface activities that will be
required, and any mitigation measures that will be used to reduce
surface impacts as part of the rehabilitation method proposed.

7. The Contractor shall describe the method(s) proposed for annular
space grouting, including grouting subcontractor qualifications.

The location and number of access shafts shall be submitted for review
and approval by the Owner. This submittal shall include any appropriate
sketches deemed necessary by the Owner. The Contractor shall be
responsible for obtaining all necessary permits as they relate to the
location, should they be accepted by the Owner. The pits or shafts shall be
spaced in conformance with the pipe manufacturer’s recommended
maximum allowable insertion force that can be exerted onto the liner pipe.

1. The size of the access shaft shall be as small as possible, but
sufficient to allow access for the Contractor's work. The
Contractor shall be responsible for support of excavation and
dewatering of each shaft. The shaft(s) shall be removed and
backfilled as soon as practical upon completion of the liner pipe,
and the surface restored in accordance with the applicable
provisions of these Specifications.

2. The Contractor shall minimize the time that a shaft remains open at
a particular site. Considerations shall be provided to complete and
coordinate all work, including cleaning, pre-installation internal
inspection, pipe and manhole/catchbasin rehabilitation (as needed),
post-installation internal inspection, and acceptance, so as to
minimize surface disturbances.

The Contractor shall submit the particular method by which he plans to
maintain traffic, signing schedule, access roads, and locations of access
locations and receiving manhole to the Owner for review and approval prior

to commencement of construction.

Omitted.

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The Contractor shall submit the method(s) and equipment he proposes to use
for repairs of non-compliant renewal sections, defects, test sample section
repairs, or other deformities in the completed liner pipe. Such repairs shall
be in accordance with the liner manufacturer's recommended written
procedures and techniques.

The Contractor shall submit reversible direction hammer manufacturer’s
specifications including: calculated impact force, blows per minute at
recommended air supply, optimal air supply, air consumption, calculated
energy production, and average impact force during pipeline installation
progression, for the hammer to be used in pneumatic hammer assisted
sliplining.

1.4 QUALIFICATIONS

A.

The Contractor shall provide documentation supporting the qualification
criteria specified herein in Paragraphs 1.4A through 1.4D.

1. The Engineer reserves the right to request, inspect, examine, and
review information pertaining to a Contractor's proposed method(s)
for compliance with the Contract Specifications.

The qualifications of the Contractor shall be submitted so as to demonstrate
that the Contractor meets or exceeds the minimum requirements specified
herein. Any Contractor whose qualifications do not meet the minimum
qualifications shall be rejected and shall not be permitted to participate in the
construction of work specified herein.

It is the responsibility of the Contractor to confirm that any subcontractor or
manufacturer proposed for performance of the work under this section of the
Specifications can demonstrate the minimum requirements specified herein.
Rejection of any subcontractor and/or manufacturer shall not be grounds for
modifications to the Contract Documents. No change in contract time of
completion or contract cost will be allowed as a result of such rejection of a
subcontractor and/or manufacturer to meet the minimum requirements
specified herein.

The Contractor installing the pneumatically assisted sliplining pipe shall
have completed at least five (5) similar projects, in the United States of
America, in the past three (3) years on pipeline projects that included
slipline pipe installation of at least the maximum pipe diameter proposed
for the project and lengths of at least 300 continuous linear feet.

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PART 2 - PRODUCTS

2.1 MATERIALS

A. Solid Wall High Density Polyethylene Pipe (HDPE)

1.

The HDPE renewal pipe shall be manufactured from a high

density, high molecular weight polyethylene resin, which conforms

to ASTM D-1248 and meets the requirements for Type III, Class B,

Grade P34, Category 5, and has a PPI rating of PE 3408, when

compounded. The pipe produced from this resin shall have a

minimum cell classification of 345434C or D under ASTM D 3350

and shall have the following physical properties:

a. Density: 0.955 gms/cubic centimeters per ASTM D1505.

b. Flexural Modulus: Minimum 135,000 psi per ASTM D790.

C. Tensile Strength: Minimum 3,200 psi per ASTM D638.

d PENT > 100 hours at 80 degrees C, 2.4 Mpa per ASTM

F1473.

HDB@ 23 degrees C: 1,600 psi per ASTM D2837.

f. UV Stabilizer: Minimum 2% carbon black per ASTM D
1603.

@

2. The renewal pipe shall be 12” SDR 17 IPS HDPE pipe.

3.

All pipe shall be made of virgin material. No re-work, except that
obtained from the manufacturer’s own production of the same
formulation shall be used.

The pipe shall be homogenous throughout and shall be free of
visible cracks, holes, foreign material, blisters, or other deleterious
faults.

The interior surface of the HDPE pipe shall not be dark or non-
reflective in nature that could inhibit proper television inspection.

The finished HDPE pipe shall be continuous over the entire length
of an insertion run between the insertion pit and reception pit. The
HDPE pipe shall be impervious and free of any leakage from the
rehabilitated host pipe to surrounding ground, or from the
surrounding ground to the inside of the pipe.

The manufacturer of the pipe shall supply the OWNER with

certificates of compliance indicating conformance for all material
and testing requirements furnished under these Specifications.

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10.

B. Joints

Each standard pipe unit shall be clearly and permanently marked
with the nominal pipe size, the dimension ratio, the polyethylene
grade per ASTM D3350, a manufacturing standard reference e.g.
ASTM F 714, production code, date of manufacture, and
manufacturer’s trademark.

The Contractor and manufacturer shall exercise extreme care
during transportation, handling, storing, and installation of the
HDPE pipe to ensure that the pipe is not gouged or otherwise
damaged in any way. The Contractor shall store the pipe with a
cover to block ultraviolet light in accordance with the
manufacturer’s recommendations. If the HDPE pipe becomes
gouged or otherwise damaged, before or during installation, it shall
be replaced or repaired by the Contractor at no additional cost to
the Owner.

For segmental sliplining work the renewal pipe shall be 12”
nominal diameter DR17 IPS Threadliner HDPE pipe provided in
24” laying lengths as manufactured by ISCO Industries or
approved equal.

Lengths of polyethylene pipe and fittings for pneumatic hammer
assisted sliplining shall be joined by means of butt fusion.
Contractor shall engage trained personnel and utilize pipe
manufacturer's recommended equipment and techniques to join
lengths of pipe.

Lengths of polyethylene pipe and fittings for segmental sliplining
shall have a buttress style threaded connection, as provided by
ISCO Industries, or approved equal, externally wrapped with
electrofusion wire and welded, and shall be watertight when
tightened.

2.2. DESIGN CRITERIA

A. General

1.

All renewal pipe used to slipline existing pipelines shall be
designed for a minimum service life of 50 years. All renewal pipe
shall be designed to withstand the jacking or pulling forces, total
vertical and lateral loads, including, but not limited to, dead load,
live loads, and hydrostatic loads. Long-term, 50-year design shall
be based on the assumption that the existing carrier pipe provides

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no structural support to the renewal pipe, except for transmitting

loads.
2. Omitted.
B. Design Performance Limits and Design Parameters
1. The renewal pipe shall be designed such that the pipe shall not fail,

collapse, buckle, crack, or delaminate under loads. The maximum
long-term (50 years) calculated deflection under all loads shall not
exceed five percent (5%). The maximum bending strain (50 years)
developed in the wall shall not exceed three percent (3%) for

HDPE pipe.

C. The following parameters shall be used:
Depth of Cover Above Pipe Crown Actual
Depth of Groundwater Above Pipe Crown Ground Surface
Specific Weight of Soil 120 |bs./ft.
Wheel Load’ 16,000 Ibs.
Railroad Load” Not Applicable
Design Temperature 80°F
Shape Factor 4

Ovality Correction Factor

As applicable to pipe material for short-term
and long-term deflection

Deflection Lag Factor

1.0 (initial) 1.2 (50 years)

Modulus of Soil Reaction

1,200 psi

Short-Term Modulus of Elasticity

Seven (7) days under constant stress when
submerged in water, to be used for
unconstrained hydrostatic collapse resistance
design for highest external pressure resulting
from grout or groundwater above pipe.

Long-Term Modulus of Elasticity

50 years under constant stress when
submerged in water, to be used for
unconstrained buckling resistance design for
combined external loads from groundwater
and earth cover.

Minimum Factor of Safety

2.0, unless otherwise specified (not applicable
for maximum bending strain)

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Notes: ‘Design of the renewal pipe shall be based on prism load on the
renewal pipe, using the outside diameter of the renewal pipe in the
calculation.

“Impact factors to be included when depth of cover is less than 3 feet
per values recommended by AASHTO.

*Impact factors to be included when depth of cover is less than 10
feet per criteria established by AREA “Manual of Recommended
Practice”.

D. The minimum thickness of the pneumatically assisted slipline pipe to be
installed shall be as determined for the design conditions imposed.
Calculations for the determination of the required liner pipe stiffness or
DR shall be the largest pipe stiffness or smallest DR for each slipline pipe
installation reach (insertion pit to receiving pit), as determined by
calculations provided for the following parameters: (1) Maximum
Deflection; (2) minimum pipe stiffness or maximum DR; (3) ring bending
strain; (4) hydrostatic collapse resistance using short-term modulus of
elasticity, and (5) constrained buckling resistance using long-term
modulus of elasticity.

E. The Contractor shall submit test results with respect to the physical
characteristics of the pneumatically assisted slipline pipe. These tests shall
be at no additional cost to the Owner. These tests shall include the
following:

F. Tests for Tensile Strength of HDPE pipe material shall be in accordance
with ASTM D638. The minimum tensile strength shall be 3,100 psi.

1. Tests for the Determination of Environmental Stress Crack
Resistance (ESCR) shall be in accordance with ASTM F1248, with
an ESCR test equal to 2,000 hours.

PART 3 - EXECUTION
3.1 CONSTRUCTION PROCEDURE
A. Pneumatically assisted sliplining shall be performed with minimum
excavation and demolition of existing structures, and the Contractor shall re-
establish connections and minimize the disruptions to adjacent properties,

traffic, and wetlands. Excavation for point repairs or emergencies shall be
permitted, but only as approved by the Owner and permitting agencies.

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Prior to construction and delivery of materials, the Contractor shall obtain
the necessary permits and details or traffic flag persons, as appropriate.

1.

It is the intent of this contract that traffic be maintained at all times
in the areas of construction. The Contractor may be required to
halt operations and/or transport material to areas beyond immediate
work locations in order to allow minimum traffic disruptions.
Access to the site by emergency vehicles, school buses, and
residents shall be maintained at all times.

The Contractor shall submit a work plan to address the items specified
below, unless approved otherwise by the Owner.

1.

Safety - The Contractor shall carry out operations under this
Section in strict accordance with all applicable OSHA, State, and
local standards. Particular attention is drawn to those safety
requirements involving work with entry into a confined space. It
shall be the Contractor's responsibility to comply with OSHA and
NStar Electric’s standards and regulations pertaining to all aspects
of the work.

Pre-Installation Television Inspection - It shall be the responsibility
of the Contractor to video (TV) inspect the sewer pipe immediately
before pneumatically assisted sliplining, to assure that the existing
pipe conditions are acceptable for sliplining, and to locate all active
service line connections. This inspection, as well as the video
(TV) inspection after the installation, shall be paid for as per bid
item, or as directed by the Owner.

Cleaning - The Contractor shall clean the host pipe prior to
commencing pneumatically assisted sliplining operations. The
cleaning shall be sufficient to conduct pneumatically assisted
sliplining operations and to televise the host pipe to identify and
locate service connections. No additional compensation will be
made if the pipe is not sufficiently cleaned. The Contractor shall
be responsible for the proper transport and disposal of all debris
and material cleaned from the sewer.

Bypassing of Flows- When required for acceptable completion of
the pneumatically assisted sliplining, the Contractor shall provide
for continuous sewer and drainage flow around the section(s) of
pipe designated for the installation of renewal pipe. The pump
bypass lines shall be of adequate capacity and size to handle flow.

Sags in Line - If pre-installation video (TV) inspection reveals a
sag in the existing sewer that is greater than one-half the diameter

02769-10

of the existing pipe; it shall be the Contractor’s responsibility to
install the renewal pipe to result in an acceptable grade without the
sag. The Contractor shall take in necessary measures to eliminate
these sags, as approved by the Owner by pipe renewal; digging a
sag elimination pit and bringing the bottom of the pipe trench to a
uniform grade in line with the existing pipe invert or by other
measures that shall be acceptable to the Owner.

Point Repairs - Point repairs are repairs to the existing pipeline
required prior to renewal work. Point repairs shall be located
during the internal inspection of the pipeline. The Contractor shall
repair areas requiring “point repair’ after cleaning and pre-
construction internal inspection is complete and prior to
commencement of renewal work. Contractor shall submit to the
Owner the proposed method(s) of point repair for each area
requiring a point repair for review and approval. Point repairs also
include the joint and pipe infiltration which may affect the
pneumatically assisted sliplining. The Contractor shall notify the
Owner not less than 48 hours in advance of making any particular
point repair. Work shall include supplying necessary materials,
equipment, excavation, sewage diversion in bypassing, dewatering,
and labor.

3.2 INSERTION PITS

A.

Prior to commencing any excavation, Contractor shall submit a detailed
Plan of Construction to identify the location and number of all proposed
insertion pits to the Owner for review. The pits shall be spaced in
conformance with the Liner Pipe Manufacturer's recommended maximum
allowable insertion force that can be exerted onto the liner pipe.

The Contractor shall locate access shafts or insertion pit(s) as shown on
the drawings. The use of additional pits or different locations, as shown,
must be approved, in writing, by the Engineer prior to construction.
Receiving pit locations are not shown on the drawings. Receiving pits
shall be located at manholes or structures only and no excavation shall be
allowed unless a new manhole is designated on the Drawings or as
otherwise approved in writing by the Engineer. Access for receiving pits
shall be through existing manholes or structures. All insertion or
receiving pits shall be designed to be constructed with wood or steel
sheeting, steel plates or steel trench boxes. Shafts or pits shall be
designed in conformance with Section 02210 - Earthwork.

The size of access/receiving shafts shall be as small as possible but
sufficient to allow access for the Contractor's work. The Contractor is

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responsible for dewatering of each shaft. The shaft(s) shall be removed
and backfilled as soon as practical upon completion of the liner pipe and
the surface restored in accordance with the applicable provisions of these
specifications.

The Contractor shall minimize the time that a shaft remains open at a
particular site. Considerations shall be provided to complete and
coordinate all work including cleaning, pre-installation internal
inspection, pipe renewal, post-installation internal inspection and
acceptance so as to minimize disturbances. The Contractor shall
recognize that shafts shall not be removed/closed until the renewal pipe
has been internally inspected and accepted by the Engineer and it is
intended that each shaft shall be removed/closed and backfilled within
two calendar days from completion of the pipeline renewal work and
service reconnections.

3.3 INSTALLATION PROCEDURES

A.

Prior to pneumatically assisted sliplining pipe installation, the Contractor
shall insert a length of liner pipe test section to ensure that the existing
pipe is free of obstructions. The test section shall have an outside
diameter equal to or approximating the maximum allowable tolerance for
each reach and class of liner pipe and a length equal to that of the proposed
liner pipe for each reach of pipeline to be sliplined. The test section may
be left in place, provided it is not damaged and it meets design basis for
pipe reach. A new pipe section shall be provided at no additional cost, if
the Owner considers the test section damaged, worn, or not representative
of the actual liner pipe to be installed.

1. In the event the test section fails to pass through a reach, the
Contractor shall, at no additional cost to the Owner, use a shorter
test section(s) to determine if shorter lengths of liner pipe can be
successfully installed; provide for sliplining in the opposite
direction with a joint match at the point of obstruction; relocate an
access shaft or pit, with the approval of the Owner, to complete the
sliplining operation; and/or other means with prior approval by the
Owner.

2. Upon successful completion of the insertion of the test section, the
existing host pipe shall be considered ready to receive the liner
pipe and commencement of the pneumatically assisted sliplining
operation. The proposed liner pipe shall be lowered down into the
insertion pit and inserted into the existing host pipe. The
Contractor shall submit details for the pushing or pulling head to
be used, including the maximum allowable pushing or pulling

02769-12