Western Water Template · Sewerage Code of Australia WSA 02-2014-3.1 Melbourne ... specified on the...

SEWERAGE DESIGN STANDARD

Supplementary Information to the WSAA Sewerage Code of Australia

WSA 02-2014-3.1 Melbourne Retail Water Agencies Edition Version 2

Western Water

January 2018

CAPITAL DEVELOPMENT | SEWERAGE DESIGN STANDARD

Version: 1 Controlled Document Document Owner: STANDARDS TEAM

Ref: CAPDEV - STANDARD - SEWERAGE DESIGN of 23 Uncontrolled when Printed

Authorised: GENERAL MANAGER SUSTAINABLE WATER SOLUTIONS Date Authorised: January 2018

Executive Summary

This Design Standard has been produced as a guide for use by technical personnel involved with the

design and construction of gravity sewers within Western Water’s service area.

The design and construction of sewer mains required for provision of services to subdivisions and other

land development works should be carried out in accordance with this Design Standard and the WSAA

Sewerage Code of Australia WSA 02-2014-3.1 Melbourne Retail Water Agencies Edition Version 2.0

(“the Sewerage Code”). The requirements set out in this Design Standard take precedence over those

in the Sewerage Code.

This document is a guideline only, and not intended to be a detailed specification for the purposes of

the design and construction of sewer mains. Designers and constructors are responsible for the

respective aspects of the design and construction process and the justification of any variations from

the requirements set out in the Sewerage Code and this Design Standard. Where there are any

discrepancies or inconsistencies between the Sewerage Code, this Design Standard, or any other

documents, standards or practices these should be discussed with Western Water prior to proceeding.

Enquiries or suggestions relating to the information set out in this Design Standard are welcome and

can be directed via email to [email protected]

Western Water will update this document as changes become necessary, and the most up to date

version will be available on our website.

This edition applies to all developments and sewerage design projects issued to commence design on

or after the publication date unless otherwise stated in writing by Western Water.

mailto:[email protected]





Table of Contents

2.0 SYSTEM PLANNING .................................................................................................. 5

2.3 PLANNING PRNCIPLES .............................................................................................. 5

2.3.4 Provision for future gauging needs ....................................................................... 5

2.4 PLANNING PARAMETERS ........................................................................................... 5

2.4.1 Loading per serviced lot ...................................................................................... 5

2.4.2 Estimating future catchment loads ........................................................................ 5

2.4.5 Environmental, cultural and heritage impacts ......................................................... 5

3.0 FLOW ESTIMATION .................................................................................................. 5

3.3 Design Flow Estimation Method .................................................................................. 5

3.3.5 Flow schedule .................................................................................................... 5

4.0 PRODUCTS AND MATERIALS ...................................................................................... 5

4.1 General .................................................................................................................. 5

5.0 DETAIL DESIGN ....................................................................................................... 6

5.2 Detailed Design Considerations .................................................................................. 6

5.2.4 Location of sewers ............................................................................................. 6

5.3 Horizontal Alignment of Sewers .................................................................................. 6

5.3.2 Roads, reserves and open space .......................................................................... 6

5.3.8 Horizontal curves in sewers ................................................................................. 6

5.6 Vertical Alignment of Sewers ..................................................................................... 6

5.6.4 Lot servicing requirements .................................................................................. 6

5.6.7 Vertical curves in sewers ..................................................................................... 6

5.6.8 Compound curves .............................................................................................. 7

7.0 MAINTENANCE STRUCTURES ..................................................................................... 7

7.3.2 Maintenance structure spacing—Reticulation sewers ................................................ 7

7.4 SPECIAL CONSIDERATIONS FOR LOCATION OF MAINTENANCE STRUCTURES ................... 7

7.9 MAINTENANCE STRUCTURE COVERS .......................................................................... 8

7.9.1 General ............................................................................................................ 8

8.0 ANCILLARY STRUCTURES .......................................................................................... 8

8.2 Water Seals and Boundary Traps ................................................................................ 8

8.2.1 Boundary traps on sanitary drains ........................................................................ 8

8.2.2 Water seals and gas check MHs ............................................................................ 8

10.0 DESIGN REVIEW AND DRAWINGS .............................................................................. 8

10.5 Recording of Work as Constructed Information ............................................................. 8





Part 2: Construction ............................................................................................................. 8

16.11 Markers ............................................................................................................... 8

16.11.3 MRWA Marker Posts ........................................................................................... 8

Appendix A – Sewerage Design Checklist ................................................................................. 9

Appendix B – CCTV Inspection Acceptance Criteria For Newly Constructed Sewerage Assets ......... 14





Part 1: Planning and Design

2.0 SYSTEM PLANNING

2.3 PLANNING PRNCIPLES

2.3.4 Provision for future gauging needs

Include the following general information:

Western Water shall advise if and where gauging stations are required

2.4 PLANNING PARAMETERS

2.4.1 Loading per serviced lot


Information pertaining to Land Use Zoning and existing infrastructure owned and maintained shall be

obtained from Western Water

2.4.2 Estimating future catchment loads


Estimating the future catchment load is to be based upon EP (Equivalent Population) and a residential

loading rate of 180l/EP/Day.

2.4.5 Environmental, cultural and heritage impacts


An Environmental and heritage plan will be required at the planning stage refer to Clause 5.2.7 WSA

02_2014 MRWA version 2.

3.0 FLOW ESTIMATION

3.3 Design Flow Estimation Method

3.3.5 Flow schedule

Include the following information:

A schedule of all flows is to be provided in a CSV (comma delimited) file format.

4.0 PRODUCTS AND MATERIALS

4.1 General

Additional requirement:

Products and materials shall be in accordance with City West Water approved products and materials

specified on the MRWA Portal www.mrwa.com.au/Pages/Products.aspx unless otherwise amended in

this document.

http://www.mrwa.com.au/Pages/Products.aspx





5.0 DETAIL DESIGN

5.2 Detailed Design Considerations

5.2.4 Location of sewers

5.2.4.3 Sewers located along rear boundaries


Sewers located along a rear boundary will not be accepted by Western Water unless it can be

demonstrated it is unavoidable.

5.3 Horizontal Alignment of Sewers

5.3.2 Roads, reserves and open space


Unless otherwise agreed for the purposes of design minor roads are to be treated as major roads

5.3.8 Horizontal curves in sewers

Replace second paragraph with the following:

Western Water will only permit horizontal curves by deflecting consecutive flexible joints, provided no

individual joint deflection exceeds the manufacturer’s recommended maximum joint deflection of a single

socket and using full pipe lengths. In some pipe systems the maximum allowable joint deflection is marked

on the pipe socket.

5.6 Vertical Alignment of Sewers

5.6.4 Lot servicing requirements

5.6.4.3 Serviced area requirements for industrial and commercial lots

Addendum:

Western Water will not accept partial lot servicing unless it can be demonstrated that there are no

alternatives.

5.6.7 Vertical curves in sewers

Replace with the following:

Western Water will only accept vertical curves where:

The curvature is within the limitations as stated for horizontal curves

AND

It can be demonstrated that the lowest whole life cost cannot otherwise be achieved





5.6.8 Compound curves

Replace with the following

Western Water does not permit the use of compound curves

7.0 MAINTENANCE STRUCTURES

7.3.2 Maintenance structure spacing—Reticulation sewers

Replace up to and including MRWA Table 7.1 with the following:

For reticulation sewers, the maximum distance between any two consecutive maintenance structures

shall be 150 m.

Maximum spacings shall be in accordance with Table 7.1 below

TABLE 7.1

MAXIMUM SPACINGS

Upstream

Structure

Downstream

Structure

Land Type Max Separation

End of Line or IS MS, MC Private Property 80 m

End of Line or IS MS, MC or MH Public Land 100 m

MS or MC MS, MC Private Property 150 m

MS or MC MS, MC or MH Public Land 150 m

MH MS or MC Private Property 150 m

MH MS or MC Public Land 150 m

IS or MH MH (with

intermediate

structures)

Any 300 m

7.4 SPECIAL CONSIDERATIONS FOR LOCATION OF MAINTENANCE

STRUCTURES


The following locations for maintenance structures shall be avoided as far as practicable:

i. Within major road reserves;

ii. Within railway reserves (Refer to Clause 5.3.3).

iii. In floodways below 1:100 year flood levels and below high tide.

iv. In coastal zones and below maximum high tide levels (Refer to Clause 5.2.7.5).

v. Where access to the structure is likely to be severely restricted e.g. foreshores





7.9 MAINTENANCE STRUCTURE COVERS

7.9.1 General

Add the following:

(e) Public play grounds

(f) School grounds

8.0 ANCILLARY STRUCTURES

8.2 Water Seals and Boundary Traps

8.2.1 Boundary traps on sanitary drains


Boundary traps are not acceptable at property boundaries

8.2.2 Water seals and gas check MHs

8.2.3.3 Gas check MHs


Gas check MHs are not approved

10.0 DESIGN REVIEW AND DRAWINGS

10.5 Recording of Work as Constructed Information

Add the following:

As Constructed information shall be provided in accordance with Section 4.6 of Western Water’s Land

Development Manual

Part 2: Construction

16.11 Markers

16.11.3 MRWA Marker Posts

Add the following:

Refer to Western Water’s approved list of materials





Appendix A – Sewerage Design Checklist

Criteria Complete Comments

Survey Datum

Is the Australian Height Datum (A.H.D) noted on design plans?

Is the Australian Map Grid (A.M.G) / Geocentric Datum of

Australia (G.D.A) noted on design plans?

Are PBMs and/or TBM's shown on design plans and are

AMG/GDA co-ordinates for these PBMs/TBMs shown?

Has the whole catchment (required to be controlled through this

development) been controlled?

Gravity Sewers, Rising Mains or Siphons

Are all sewers along the front of properties located within road

reserve and not within the property unless otherwise approved

by Western Water?

Are there any curved sewers? Note that curved sewers are only

permitted for 150mm diameter sewers.

Are all curved sewers designed correctly (radius greater than

the standard, jointing technique, no property connections on the

curved sections etc.)?

Is minimum cover achieved on all pipes?

Has continuously jointed pipe been specified for any water

crossings?

Are there any railway crossings? Has the crossing design been

carried out in accordance with the Australian Standards and

VicTrack requirements? Has VicTrack provided written approval?

Note a detail drawing for the railway crossing to 1:500 scale in

addition to a locality plan should be provided.

Are all maintenance structures located out of the railway

reserve? Is a minimum of 1m clear space provided around

maintenance structure near confined boundaries?

Are there any freeway crossings? Has the crossing design been

carried out in accordance with the Australian Standards and

VicRoads requirements? Has VicRoads provided written

approval?

Does the alignment of the pipeline cross at right angles to the

freeway?

Are all maintenance structures located clear of the freeway

reserve?

Are minimum clearances from other services achieved?






Are there any crossings of Council Drains or Melbourne

Water/Southern Rural Water drains/waterways? Has written

approval to the design been obtained?

Does the location of the rising main comply with Western Water

requirements?

Western Water approval for installation of Siphon received?

Do offsets of the sewer comply with WSAA standards?

Have all existing utilities been identified on drawings?

Has a Dial Before You Dig (DBYD) search been carried out?

Are any works proposed within a VicRoads declared road?

Are any works proposed in the vicinity of Melbourne Water

assets and/or waterways? Has the design taken into account

Melbourne Water requirements?

Has the requirement for odour control measures been assessed

and incorporated into the design?

Maintenance Structures

Does the distance between maintenance structures comply with

standards (i.e. generally 100m as per Western Water

requirements)?

Are all maintenance structures numbered in accordance with

standards?

Is the area subject to flooding?

If subject to flooding, do all maintenance holes have bolt down

covers and are all cover levels above the 1 in 5 year storm

event level?

Are there any gas check maintenance holes? Has the use of gas

check maintenance holes been approved by Western Water?

Are Gas Check maintenance holes located in the road reserve

and are there ultimately more than 50 lots connected to it?

Are there any maintenance holes greater than 6m in depth?

Are landings, handgrips, ladders etc. in accordance with

standards and are correct materials specified on design plans?

Are structural computations of maintenance structures deeper

than 6m provided?

Are all maintenance structure locations in accordance with

Western Water standards and with a minimum of 1m clearance

from confined boundaries?

Are minimum clearances to other services achieved?

Are the maintenance holes’ cover class and cover size noted on

design plans?






Have any pre-cast maintenance holes been specified? Has their

used been approved by Western Water?

Are correct diameters of maintenance holes nominated on

design plans, as well as the minimum diameter to be used?

Is detailed MH table design required to be submitted? (e.g. two

or more internal drops, three or more incoming sewers, sewers

offset from the MH centre, angle of deflection >90o)

Are MH table designs in accordance with standards?

Are there any sewers or other underground structures to be

built next to existing structures?

Are guidance notes provided to the contractor for excavation

next to existing manholes to preserve stability of the manholes

during construction?

Where connecting to existing MHs, have these been inspected

as part of the design and are details provided on the drawings

of the existing layout and modifications required? Are working

spaces still to standard?

Design of Gravity Sewers (including Hydraulics)

Are the correct pipe diameters specified in accordance with

standards?

Does the grade of each pipe comply with standards?

Are IL's of sewers correctly identified?

Are all pipe materials, pipe classes, jointing methods etc.

specified on design plans and are they all approved products?

Is the trench width provided or referred to relevant design

standards?

Has the embedment material been specified and is it suitable

for the pipe and geotechnical conditions?

Are compaction requirements for trench bottom (if required),

embedment, and backfill specified or referred to relevant

Australian Standards?

Are backfill design specifications provided or referred to WSAA

code drawing or relevant standards?

Are embedment types specified according to WSAA standard

drawings or cross section details provided?

Are any grades steeper than 1 in 10 or flatter than 1 upon

diameter?

Have trench stops been provided where required?

Is the velocity through the pipe below 3 m/s in both partial and

full flow (or under pressure flow if a pressure main)?






For steeply graded sewers, is the energy dissipated in the

maintenance hole?

Are there any sewers greater than 5m in depth?

Has the ground conditions report been provided for sewers

deeper than 5m?

Are there wet/poor ground conditions?

Has a specialist geotechnical assessment been made?

Has adequate trench design been made and relevant details

provided?

Has an Emergency Relief Structure (ERS) been incorporated in

design?

Have HGL details been submitted ensuring that there is no

possibility of overflow upstream at MHs, property drains, etc?

Are structural design computations for trench design sewer

pipes provided?

Are water seals (i.e. boundary traps) specified where required,

and has Western Water approval been obtained for their use?

Property Connections

Are all properties provided with a property branch/connection

and is the type of branch/connection nominated on design

plans?

Have any Y-property branches/connections been nominated?

(note not permitted)

Is the depth for property connections junctions and end fittings

in accordance with the standard?

Do property connections extend beyond the property/easement

boundary by a minimum of 500mm?

Gravity Sewers greater than 225mm in Diameter

Are self cleansing/slime stripping velocities achieved at PDWF?

Is the class of pipe and all embedment details shown on design

plans?

Are any sewers surcharging under 1 in 5 year floods (i.e.

PWWF)?

Are property connections only on sewers 300mm in dia. and

less?

Inverted Siphons

Are minimum velocities achieved at PDWF?

Does the difference in inlet level and outlet level comply with

Western Water standards?






Has the siphon hydraulics been designed to confirm sediments

are flushed through the downstream reach of the siphon during

PDWF?

Hazard Identification and Risk Assessment

Has the designer, in designing the sewerage system element

that is being audited, integrated hazard identification and risk

assessment methods to eliminate the risk of injury throughout

the life of the system?





Appendix B – CCTV Inspection Acceptance Criteria For

Newly Constructed Sewerage Assets





TABLE B1

ACCEPTANCE CRITERIA FOR RIGID SEWERS – VITRIFIED CLAY, STEEL REINFORCED CONCRETE

Defect/Feature Characterisation 1 Characterisation 2 Quantification 1 Acceptance determination and explanation

Cracking C L, C, S, or M Surface cracking is common in concrete and is usually

not of concern. Such cracking is usually of limited

extent and does indicate structural failure. However,

surface cracking that is extensive may indicate a

problem with concrete quality. Report in remarks for

the Water Agency to review.

Surface cracking is unlikely in VC products currently on

the market although it should be noted that internally

glazed VC pipes are now again available. If surface

cracking is observed report in remarks for the Water

Agency to review.

Fracturing F L, C, S, or M Not acceptable – all of these types of cracking are

indicative of poor handling, unsatisfactory installation

or overloading.

Breaking B D, M, or E Not acceptable.

Deformation D Not acceptable.

Collapsed X Not acceptable.

Porous sewers

(pipes) PP

Not acceptable.

Surface damage S

* Not applicable to

VC

S, AV*, or W Report and refer to Water Agency for acceptance

determination.

Z Identify, report and refer to Water Agency for

acceptance determination.

AP*, AM*, RC*, CP*,

H* or WS*

Not acceptable - unlikely to be observed in new

construction.

RV* or RVP* Not acceptable - cover to reinforcement is clearly less

than specified in relevant pipe standard.

continued






Lining defective

PL**

** Applicable to

plastics lined

concrete pipes only

D, E, WD or L Defects indicated not acceptable. The lining is placed

during manufacture in the top 330° of the pipe and is

required to be joined after installation at each pipe

joint.

Z Lining on invert of pipe (pipe installed upside down) –

not acceptable.

Identify other defects, report in remarks and refer to

Water Agency for acceptance determination.

Deposits on wall or

invert DE

E Not acceptable - should not occur in new sewer.

S or R Not acceptable.

C Not acceptable.

W or Z Identify material, report in remarks and refer to Water

Agency for acceptance determination.

Exfiltration EX Not acceptable – exfiltration is most likely associated

with a joint defect or broken pipe.

Infiltration S S, D, R or G Not acceptable.

Ingress of soil ING Not acceptable.

Roots R T, F, or M Not acceptable – the presence of roots indicated a

possible problem with installation at joints, poor quality

concrete, cracks and/or fractures.

Joint displacement

JD

L Not acceptable – if joint displacement exceeds

maximum specified by manufacturer for the joint.

R >5 mm for pipe

sizes up to DN 250

>10 mm for pipe

sizes from above

DN 250 to DN 500

>20 mm for pipe

sizes above DN 500

Not acceptable.






A Normally unacceptable on ‘straight’ sewers (see

maximum limits for ‘curved’ sewers below). Report

deflection and refer to Water Agency for acceptance

determination.

For ‘curved’ sewers using ‘pulled’ pipes report the

distance between the end of spigot and end of socket

(adjoining pipe) at worst point and the angular

deflection at the joint. Refer to Water Agency for


Jointing material

(seal) intrusion) JI

R N, HH, HL or B Not acceptable.

Z Report and refer to Water Agency for acceptance

determination.

Point repair RP L, I, S, H or IC Some techniques may not be acceptable in new sewers.

Report and refer to Water Agency for acceptance

determination.

Z Identify repair technique, report in remarks and refer to


Defective repair RX M or P Not acceptable.

B or Z Determine extent of ‘bellies’ or other defects. Report

and refer to Water Agency for acceptance

determination.

Obstruction OB B, M, I, J or C Not acceptable.


determination.

P or S Report and refer to Water Agency for acceptance

determination.

Flow (water) level

WL

>15mm or 5%

whichever is the

greater (no flow

from upstream and

no blockage or

debris

downstream)

Not acceptable above the limit indicated.

Flow (water) level above a nominal level may be caused

by flow from upstream or a blockage, debris in the

invert or some other feature downstream. It is not a

defect itself.

It does indicate a defect. However, where there is no

flow from upstream and there is no blockage

downstream, the most likely defect indicated in this






situation is gradient misalignment (i.e. one of more

pipes have dropped below the grade and ponding has

occurred).

Defective junction

JX

P, D, B, BC, SR, SE or

Z

Not acceptable.

Connection CN G or P Not acceptable - junction required.





TABLE B2

ACCEPTANCE CRITERIA FOR FLEXIBLE SEWER PIPES – PLASTICS (PVC, PE, PP, GRP), DUCTILE IRON AND STEEL

Defect/Feature Characterisation 1 Characterisation 2 Quantification 1 Remarks

Cracking C L, C, S, or M S Not acceptable. Not usually a feature of these pipe

materials but may be apparent in cement mortar linings

and internal corrosion barrier (“gel-coat”) of GRP.

Report as Lining defective ‘PL’.

L, C, S, or M W Not acceptable. Not usually a feature of these pipe

materials but where it does occur, it would generally

indicate excessive external loads from construction

equipment.

Fracturing F L, C, S, or M Not acceptable.

Breaking B D, M, or E Not acceptable.

Deformation D >5% after 60 days Not acceptable.

Local or point

deformation – no

code

No code

Record General

Comment GC

Report and refer to Water Agency for acceptance

determination. An unusual feature with many possible

causes.

Collapsed X Not acceptable.

Porous sewers

(pipes) PP

Not acceptable. Not likely to be a feature of these

pipes.

Surface damage S W Report and refer to Water Agency for acceptance

determination.

Z Identify, where possible, report and refer to Water


CP or H Not acceptable. Unlikely to be observed in new

construction.

Lining defective PL D●, E●* or B●* Not acceptable

* Applicable to internal corrosion barrier in GRP pipes

* Applicable to PE internal lining of ductile iron and

steel pipes






Z Identify other defects, where possible, report and refer

to Water Agency for acceptance determination.

Deposits on wall

or in invert DE

E Not acceptable - Should not occur in new sewer.

S or R Not acceptable.

C Not acceptable.

W or Z Identify, where possible, report and refer to Water


Exfiltration EX Not acceptable – exfiltration is most likely associated

with a joint defect or broken pipe.

Infiltration S S, D, R or G Not acceptable.

Ingress of soil ING Not acceptable.

Roots R T, F, or M Not acceptable – the presence of roots indicated a

possible problem with installation at joints, poor quality

concrete, cracks and/or fractures.

Joint displacement

JD

L Not acceptable – if joint displacement exceeds

maximum specified by manufacturer for the joint.

R >5 mm for pipe

sizes up to DN 250

>10 mm for pipe

sizes from above

DN 250 to DN 500

>20 mm for pipe

sizes above DN 500

Not acceptable.

A Normally unacceptable on ‘straight’ sewers (see

maximum limits for ‘curved’ sewers below). Report

deflection and refer to Water Agency for acceptance

determination.

For ‘curved’ sewers using ‘pulled’ pipes report the

distance between the end of spigot and end of socket

(adjoining pipe) at worst point and the angular

deflection at the joint. Refer to Water Agency for


Jointing material R N, HH, HL or B Not acceptable.






(seal) intrusion) JI Z Report and refer to Water Agency for acceptance

determination.

Point repair RP L, I, S, H or IC Some techniques may not be acceptable in a new

sewer. Report and refer to Water Agency for acceptance

determination.

Z Identify repair technique, report in remarks and refer to


Defective repair

RX

M or P Not acceptable.

B or Z Determine extent of ‘bellies’ or other defects, report

and refer to Water Agency for acceptance

determination.

Obstruction OB B, M, I, J or C Not acceptable.


determination.

P or S Report and refer to Water Agency for acceptance

determination.

Flow (water) level

WL

>15mm or 5%

whichever is the

greater (no flow

from upstream and

no blockage or

debris

downstream)

Not acceptable above the limit indicated.

Flow (water) level above a nominal level may be caused

by flow from upstream or a blockage, debris in the

invert or some other feature downstream. It is not a

defect itself.

It does indicate a defect. However, where there is no

flow from upstream and there is no blockage

downstream, the most likely defect indicated in this

situation is gradient misalignment (i.e. one of more

pipes have dropped below the grade and ponding has

occurred).

Defective junction

JX

P, D, B, BC, SR, SE or

Z

Not acceptable.

Connection CN G or P Not acceptable - junction required.





TABLE B3

ACCEPTANCE CRITERIA PIPE AND FITTING CONFIGURATION – ALL SEWERS

The configuration of items in a new sewer is usually defined in design drawings, standard drawings and specifications Compliance with some of these requirements may be determined by inspection

The inspector shall have a copy of design drawings, standard drawings and specifications applicable to the works being inspected for reference in determining the acceptance of nominated and other features.

The following table describes nominated features that are to be reported to the Water Agency.

Feature Description Acceptance determination and explanation

Rocker

pipes

These a shorter pipes than the normal unit pipe length and

are required by some Water Agencies adjacent to structures

such as maintenance holes, other structures and concrete

encasement

The purpose is to allow for differential settlement between

the structure and the pipeline without cracking, fracturing or

distortion of the pipe adjacent to the structure

The required length of rocker pipe and the configuration of pipes at the

structure are specified in design drawings, standard drawings and or

specifications for particular pipe materials.

The inspector should record the distance at each joint adjacent to the

structure to determine the length of the rocker pipe and report it in

remarks.

Length outside of tolerance of ± 150mm of required length not

acceptable – refer to Water Agency for acceptance determination.

Bends Bends occur in some sewers at changes of direction and or

grade. In some cases compound bends (vertical and

horizontal) may be encountered

In small diameters up to DN 225 bends are likely to be moulded or post-formed long radius. For DN 225 it is likely

that bends will be fabricated in a ‘lobster back’ with a series

of mitre cuts and the pipes joined with epoxy, hot air

welding or some other technique

Not acceptable if the camera unit cannot pass through the bend.

Not acceptable if jointing materials at mitres intrude more than 10mm

into the sewer.

The transition to bend from straight line should not exceed the angular

deflection for the joint system used Record joint deflection if

observable.

Where the installation of the bend results in ponding the acceptance

criteria applied for maximum water level in the previous tables shall

also be applied.

The distance at the start and finish of bends shall be recorded in the

inspection report.

Connections This is where another sewer to provide a service for a

customer has been connected to the pipeline being

inspected after the pipeline has been installed The

connection is formed by making a hole in the original pipe

and setting the connecting pipe in place

Not acceptable.





Feature Description Acceptance determination and explanation

This feature is not part of new sewer construction

continued

Junction A junction is a prefabricated fitting installed as part of the

original construction or post construction by inserting the

junction fitting in the pipeline

Junctions are provided to allow customers to connect house

drains directly to the sewer or allow a property connection

sewer to be extended to the customer’s property

Acceptable configurations of junctions should be specified by

the Water Agency

Not acceptable if configuration varied from Water Agency’s

specification/standard drawing.

All junctions for direct customer connection should be provided with a

PVC plain wall solvent weld socket with screwed cap or for VC, a

plugged VC to PVC plain wall adaptor

Inspect each junction lateral and report compliance

Maintenance

shafts and

chambers

Provide access to the sewer for maintenance equipment but

not person entry

May have an integral bend or may have an adjoining

(generally upstream) long radius bend

Can have up to three inlets

Not acceptable if the CCTV camera and transportation unit cannot

traverse through the maintenance shaft.

The transition to maintenance shaft from bend or straight line must not

exceed the angular deflection for the joint system used

Record joint deflection if observable and refer to Water Agency for


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