**Construction Specification 745---Plastic Pipe**

**1. Scope**

The work consists of furnishing and installing plastic pipe (except
corrugated polyethylene tubing) and the necessary fittings and
appurtenances as shown on the drawings or as specified herein.

**2. Material**

> **a.** **Pipe -** The pipe shall be as uniform as commercially
> practicable in color, opaqueness, density, and other specified
> physical properties and free from visible cracks, holes, foreign
> inclusions, or other defects. The dimension of the pipe shall be
> measured as prescribed in ASTM D 2122.
>
> Unless otherwise specified, the pipe shall conform to the requirements
> listed in the specification and the requirements shown on the
> drawings.
>
> **b. Fittings and Joints**
>
> Fittings and joints shall be of schedule, SDR, or DR, pressure class,
> external load carrying capacity, or pipe stiffness that equals or
> exceeds that of the plastic pipe. The dimension of fittings and joints
> shall be compatible with the pipe and measured in accordance with ASTM
> D 2122. Joints and fittings shall be as uniform as commercially
> practicable in color, opaqueness, density, and other specified
> physical properties and free from visible cracks, holes, foreign
> inclusions, or other defects.
>
> Fittings and joints shall conform to the requirements of the
> applicable specification referenced in the ASTM or AWWA specification
> for the pipe and the requirements shown on the drawings.
>
> **c.** Solvents
>
> Solvents for solvent welded pipe joints shall be compatible with the
> plastic pipe used and shall conform to the requirements of the
> applicable specification referenced in the ASTM or AWWA specification
> for the pipe, fitting or joint.
>
> **d.** Gaskets
>
> Rubber gaskets for pipe joints shall conform to the requirements of
> ASTM F 477, Elastomeric Seals (Gaskets) for Joining Plastic Pipe.

**3. Handling and storage**

Pipe shall be delivered to the job site and handled by means that
provide adequate support to the pipe and do not subject it to undue
stresses or damage. When handling and placing plastic pipe, care shall
be taken to prevent impact blows, abrasion damage, and gouging or
cutting (by metal edges and/or surface or rocks). The manufacturer\'s
special handling requirements shall be strictly observed. Special care
shall be taken to avoid impact when the pipe must be handled at a
temperature of 40 degrees Fahrenheit or less.

Pipe shall be stored on a relatively flat surface so that the barrels
are evenly supported. Unless the pipe is specifically manufactured to
withstand exposure to ultraviolet radiation, it shall be covered with an
opaque material when stored outdoors for 15 days or longer.

**4. Excavation**

Excavation shall be in accordance with Construction Specification 721,
Excavation, and Section 11 of this specification or as shown on the
drawings.

The pipe foundation shall be excavated a minimum of 4 inches lower than
the pipe grade shown on the drawings or staked in the field whenever
bedrock, boulders, cobbles, or other material that may cause pipe damage
is encountered at planned pipe grade.

**5. Laying the pipe**

Plastic pipe conduits complete with fittings and other related
appurtenances shall be installed to the lines and grades shown on the
drawings or specified in Section 11 of this specification. The pipe
shall be installed so that there is no reversal of grade between joints
unless otherwise shown on the drawings. The pipe shall not be dropped or
dumped on the bedding or into the pipe trench. The ground surface near
the pipe trench shall be free of loose rocks and stones greater than 1
inch in diameter. This ensures that rock will not be displaced and
impact the pipe.

Just before placement, each pipe section shall be inspected to ensure
that all foreign material is removed from inside the pipe. The pipe ends
and the couplings shall be free of foreign material when assembled. At
the completion of a work shift, all open ends of the pipeline shall be
temporarily closed off using a suitable cover or plug.

Care shall be taken to prevent distortion and damage during hot or cold
weather. During unusually hot weather (daytime high temperature of more
than 90 °F), the pipe assembled in the trench shall be lightly
backfilled or shaded to keep it as near to ground temperature as
possible until final backfill is placed. Backfill operations should be
performed during daily construction periods when the ground temperature
and the temperature of the pipe do not vary more than 40 degrees
Fahrenheit.

Perforated pipe shall be installed with the perforations down and
oriented symmetrically about the vertical centerline. Perforations shall
be clear of any obstructions on the inside and outside of the pipe when
the pipe is approved by the engineer for backfill.

During installation, the pipe shall be firmly and uniformly bedded
throughout its entire length, to the depth and in the manner specified
in Section 11 of this specification or as shown on the drawings.
Bell-holes shall be placed in bedding material under bells, couplings,
and other fittings to assure the pipe is uniformly supported throughout
its entire length. Blocking or mounding beneath the pipe to bring the
pipe to final grade is not permitted.

**6. Backfill**

**Initial backfill---**Unless otherwise specified, initial backfill to 6
inches above the top of the conduit is required. Earth haunching and
initial backfill material shall consist of soil material that is free of
rocks, stones, or hard clods more than 1 inch in diameter. Coarse
backfill material shall be the specified sand, gravel, crushed rock, or
drainfill material.

Initial backfill shall be placed in two stages. In the first stage
(haunching), backfill is placed to the pipe spring line (center of
pipe). In the second stage, it is placed to 6 inches above the top of
the pipe.

The first stage material shall be worked carefully under the haunches of
the pipe to provide continuous support throughout the entire pipe
length. The haunching backfill material shall be placed in layers that
have a maximum thickness of about 6 inches and are compacted as
specified in Section 11 of this specification or as shown on the
drawings. During compaction operations, care shall be taken to ensure
that the tamping or vibratory equipment does not come in contact with
the pipe and the pipe is not deformed or displaced.

When pressure testing is not specified, the pipe shall be covered with a
minimum of 6 inches of backfill material as soon as possible following
assembling of the pipe in the trench, but not later than within the same
day that placement has occurred. When pressure testing is specified,
sufficient backfill material shall be placed over the pipe to anchor the
conduit against movement during pressure testing activities.

**Final backfill---**Final backfill shall consist of placing the
remaining material required to complete the backfill from the top of the
initial backfill to the ground surface, including mounding at the top of
the trench. Final backfill material within 2 feet of the top of the pipe
shall be free of debris or rocks larger than 3 inches nominal diameter.
Coarse backfill material shall be the specified sand, gravel, crushed
rock, or drainfill. Final backfill shall be placed in approximately
uniform, compacted layers. Final backfill compaction requirements shall
be as specified in Section 11 of this specification or as shown on the
drawings.

Vehicles or construction equipment shall not be allowed to cross the
pipe until the minimum earth cover and required density as specified in
Section 11 of this specification has been obtained.

**7. Joints**

Unless otherwise specified in section 14 of this specification or shown
on the drawings, joints shall be either bell and spigot type with
elastomeric gaskets, coupling type, solvent cement bell and spigot, or
jointed by butt heat fusion. When a lubricant is required to facilitate
joint assembly, it shall be a type having no deleterious affect on the
gasket or pipe material.

Pipe joints shall be watertight at the pressures specified except where
unsealed joints are indicated.

Pipe shall be installed and joined in accordance with the
manufacturer\'s recommendations. Laying deflections and joint fitting or
stab depths shall be within the manufacturer\'s recommended tolerances.

When solvent cement joints are specified for PVC or ABS pipe and
fittings, they shall be made in accordance with the following ASTMs and
the related appendix of each ASTM; D 2855 for PVC pipe and fittings and
D 2235 for ABS pipe and fittings.

Flanged, banded, heat-fusion, or elastomeric-sealed mechanical joints
shall be used when joining polyethylene (PE) and high density
polyethylene (HDPE) pipe and fittings unless otherwise specified in
section 14 of this specification or as shown on the drawings.

Pipe ends shall be cut square and be deburred to provide a uniform,
smooth surface for the jointing process. Reference marks shall be placed
on the spigot ends to assist in determining when proper seating depth
has been achieved within the joint.

**8. Fittings**

Unless otherwise specified, steel fittings, valves, and bolted
connections shall be painted or coated as recommended by the
manufacturer.

Fittings for nonpressure pipe shall be of the same or similar material
as the pipe and shall provide the same durability, watertightness, and
strength as the pipe unless otherwise specified.

**9. Thrust blocks and anchors**

When specified, concrete thrust blocks and anchors shall be installed as
shown on the drawings or specified in Section 11 of this specification.

The concrete for the thrust blocks and anchors shall conform to the
requirements of Construction Specification 732, Structure Concrete, for
Class 3000M concrete unless otherwise specified in Section 11 of this
specification.

The thrust block cavity shall be hand dug into undisturbed soil or
previously placed compacted backfill. The cavity shall be formed with
soil or wood to hold the freshly placed concrete without displacement
until an initial set has occurred.

When excavation beyond the designated trench widths and depths as shown
on the drawings or specified in Section 11 of this specification occurs
at locations where installation of concrete thrust blocks is required,
the contractor shall install an alternative thrust block provision. The
concrete thrust block shall have a thickness of one pipe diameter and a
contact face area that shall be formed against the pipe as shown on the
drawings or specified in Section 11 of this specification. Backfill
shall be placed on all sides of the thrust block and to the sides of the
excavation. It shall be compacted as specified for initial backfill.

**10. Measurement and payment**

***Method 1---***For items of work for which specific unit prices are
established in the contract, the quantity of each kind, size, and class
of pipe is determined to the nearest foot by measurement of the laid
length along the crown centerline of the conduit. Payment for each kind,
size, and class of pipe is made at the contract unit price for that
kind, size, and class. Such payment constitutes full compensation for
furnishing, transporting, and installing the pipe including excavation,
shoring, backfill, bedding, thrust blocks, and all fittings,
appurtenances, and other items necessary and incidental to the
completion of the work. Payment for appurtenances listed separately in
the bid schedule is made at the contract prices for those items.

***Method 2---***For items of work for which specific unit prices are
established in the contract, the quantity of each kind, size, and class
of pipe is determined as the sum of the nominal laying lengths of the
sections used. Payment for each kind, size, and class of pipe is made at
the contract unit price for the kind, size, and class. Such payment
constitutes full compensation for furnishing, transporting, and
installing the pipe including excavation, shoring, backfill, bedding,
thrust blocks, and all fittings, appurtenances, and other items
necessary and incidental to the completion of the work. Payment for
appurtenances listed separately in the bid schedule is made at the
contract prices for those items.

***Method 3---***For items of work for which specific unit prices are
established in the contract, the quantity of each kind, size, and class
of pipe is determined to the nearest foot by measurement of the laid
length along the crown centerline of the conduit. Payment for each kind,
size, and class of pipe is made at the contract unit price for the kind,
size, and class. Such payment constitutes full compensation for
furnishing, transporting, and installing the pipe including shoring, all
fittings, thrust blocks, appurtenances, and other items necessary and
incidental to the completion of the work. Payment for appurtenances
listed separately in the bid schedule is made at the contract prices for
those items.

***Method 4---***For items of work for which specific unit prices are
established in the contract, the quantity of each kind, size, and class
of pipe is determined as the sum of the nominal laying lengths of the
pipe sections used. Payment for each kind, size, and class of pipe is
made at the contract unit price for that kind, size, and class. Such
payment constitutes full compensation for furnishing, transporting, and
installing the pipe including shoring, all fittings, thrust blocks,
appurtenances, and other items necessary and incidental to the
completion of the work. Payment for appurtenances listed separately in
the bid schedule is made at the contract prices for those items.

***Methods 3 and 4---***Excavation, backfill, and bedding is paid
separately under their respective bid items.

***All measurement and payment methods---***Compensation for any items
of work described in the contract, but not listed in the bid schedule,
is included in the payment for the item of work to which it is made
subsidiary. Such items and items to which they are made subsidiary are
identified in Section 11 of this specification.

**11. Items of work and construction details**

Items of work to be performed in conformance with this specification and
the construction details therefore are:

[Bid Item 17, 6-in. Diameter PVC Pipe, Perforated]{.underline}

(1) This item shall consist of furnishing and installing SDR 26,
    PVC-1120, ASTM D-2241 perforated PVC pipe and fittings in accordance
    with the details shown on the drawings.

(2) Drainfill adjacent to the pipe shall be compacted as required in
    Section 8 of Specification 724, Drainfill.

(3) Measurement and payment will be by Method

[Bid Item 16, 6-in. Diameter PVC Pipe, Nonperforated.]{.underline}

(1) This item shall consist of furnishing and installing SDR 26,
    PVC-1120, ASTM D-2241 nonperforated PVC pipe and fittings in
    accordance with the details shown on the drawings.

(2) Backfill adjacent to the pipe shall be hand compacted for a distance
    of two feet from the circumference.

(3) Measurement and payment will be by Method

[Bid Item 18, Small Animal Guard]{.underline}

(1) This item shall consist of furnishing and installing the small
    animal guard as shown on the drawings.