QUU Low Pressure Sewers – 2011

QUU Low Pressure Sewers

– 2011

Queensland Urban Utilities Technical Standard - Low Pressure Sewers

Part A

Doc Id: Technical Standards – Low Pressure Sewers (2011).doc

Issued January 2011 V1

Printed copies of this document should be verified for currency against the published electronic copy. of 34

INTRODUCTION

Written consent from QUU is required for acceptance of low pressure sewers.

Low pressure sewers are not a substitute for gravity sewers. They may only be used where the construction of gravity sewers are not feasible.

Where site constraints may make a gravity sewer difficult to construct, the developer shall negotiate with Queensland Urban Utilities to obtain approval in the planning stage of the project to use low pressure system.

Low pressure sewers may be used for residential lots or non-residential lots where effluent is equivalent to residential. For large industrial or commercial development, alternative configurations need to be considered.

All on property components of a low pressure sewerage system including the house drain, the grinder pump(s) and collection tank, control system, property discharge line and boundary kit up to but not including the property isolating valves shall be owned and maintained by the property owner. On property components are to be approved and accepted by Council’s Plumbing Section. All components outside the serviced property shall be owned and maintained by Queensland Urban Utilities.

The detailed design of low pressure sewer system including all “on-property” and pressure sewer network components shall be certified and guaranteed by a manufacturer/supplier of the low pressure sewer pumps. All calculations for the system including sizing of network shall be supplied to QUU for review and approval.

Queensland Urban Utilities

Technical Standard - Low Pressure Sewers

Part A


Issued: January 2011 V1


Part A - On-Property Components – Low Pressure Sewers ................................5 1 Glossary of on-property components of low pressure sewers ...................5

1.1 glossary of on-property components ................................................................... 5

2 design ...............................................................................................................8 2.1 General............................................................................................................... 8

2.2 Administrative Procedures .................................................................................. 8

2.3 Design considerations......................................................................................... 8

2.4 Existing property data collection.......................................................................... 9

2.5 Design and layout of new on-property components........................................... 10

2.6 The Work As Constructed Property Sewer Service Diagrams shall include:...... 15

3 Construction...................................................................................................17 3.1 Pressure Sewer Pumping Unit .......................................................................... 17

3.2 Electrical and Control Equipment ...................................................................... 17

3.3 Piping and associated components................................................................... 17

3.4 Inspection, Commissioning, Testing, and Acceptance ...................................... 18

3.5 Asset Tracking and Management Documentation ............................................. 19

4 Operation and Maintenance ..........................................................................20 4.1 Operation.......................................................................................................... 20

4.2 Maintenance ..................................................................................................... 20

5 Standard Documents.....................................................................................20 6 Typical Plan of On-Property components....................................................21 7 Pipe cover requirements ...............................................................................22 Part B - Network Components – Low Pressure Sewers......................................23 1. Location of Network Pipes and Fittings.......................................................24

1.1 Network Mains .................................................................................................. 24

1.2 Isolation Valves................................................................................................. 24

1.3 VACANT LOTS................................................................................................. 25

1.4 Flushing Points and Scours .............................................................................. 25

1.5 Sampling Points................................................................................................ 26

1.6 Air Release/Anti Vacuum Valves (Air valve)...................................................... 26

1.7 Provisions for Flow Meters................................................................................ 26

2. Depth of Mains ...............................................................................................27 3. DISCHARGE MH’S..........................................................................................27

3.1 Discharge MH’s - Odour management strategy ................................................ 27

4. Material Requirements...................................................................................27 4.1 Pipe Material..................................................................................................... 27

4.2 Jointing and Cleaning ....................................................................................... 28

4.3 Isolating Valves................................................................................................. 29

4.4 Air Valves ......................................................................................................... 29

5 Construction...................................................................................................30 5.1 Protection of Services ....................................................................................... 30

5.2 Connection to Sewer network ........................................................................... 30


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5.3 Type of Pits and Covers.................................................................................... 30

5.4 Pipe Embedment Material................................................................................. 30

5.5 Trench Fill ......................................................................................................... 30

5.6 Tolerances........................................................................................................ 30

5.7 Pressure Testing............................................................................................... 30

5.8 Mechanical Protection of Pipeline ..................................................................... 31

5.9 Pipeline Tracer Wires and Tape........................................................................ 31

5.10 Construction by HDD Techniques ..................................................................... 31

5.11 WORK AS CONSTRUCTED DETAILS............................................................. 33

6. Drawings

486/5/25 - S200 Low Pressure Sewers – Boundary Kit 486/5/25 - S201 Low Pressure Sewers – Typical Property Connection

Queensland Urban Utilities

Technical Standard - Low Pressure Sewers

Part A


Issued: January 2011 V1


PART A - ON-PROPERTY COMPONENTS – LOW PRESSURE SEWERS

1 GLOSSARY OF ON-PROPERTY COMPONENTS OF LOW PRESSURE SEWERS

1.1 GLOSSARY OF ON-PROPERTY COMPONENTS

Alarm Volume The volume within the Pressure Sewer Collection Tank above the pump on level and below the Alarm level. This is the volume accumulated, beyond the normal operating volume, prior to alarm activation.

Control/Alarm Panel

The power and control panel control the operation of the grinder pump and contains the audible and visual alarm components. The panel also contains a dedicated circuit breaker for power disconnection.

Electrical Cable The cable which delivers power from the building electrical distribution box to the Control/Alarm Panel.

Electrical Distribution Box

The existing electrical distribution box providing power to the building(s) being served by the Pressure Sewer System.

Emergency Storage Volume

The volume within the Pressure Sewer Collection Tank above the alarm level and below the vent located in the top of the tank. This is the volume accumulated once the alarm has been activated and prior to tank overflow.

Grinder Pump The pumping unit supplied as part of the Pressure Sewer Pumping Unit that is installed within the Pressure Sewer Collection Tank.

Low Pressure Sewers

Low Pressure Sewers consist of a network of pressure pipes and grinder pumps delivering sewage from individual properties to a treatment facility or other point of discharge. Upstream of the grinder pumps conventional house drains convey sewage from the residence to the Pressure Sewer Collection Tank

Operating Volume The volume within the Pressure Sewer Collection Tank above the pump off level and below the pump on level. This is the volume that is discharged during a normal pumping cycle.


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Pressure Sewer Collection Tank

The collection tank supplied as part of the Pressure Sewer Pumping Unit that is installed on the individual property being served by the Pressure Sewer System. The tank collects the sewage discharged from the buildings being served until the control system activates the grinder pump and the sewage is discharged from the tank. The tank capacity acts as buffer by providing additional storage prior to an alarm condition in the event that inflow exceeds pump capacity.

Pressure Sewer Network

The principal collection network in a Pressure Sewer System, consisting of small diameter pipelines and ancillary works, up to and including the isolation valve immediately outside the individual properties served by the system. The Pressure Sewer Network is owned and operated by QUU, provides for the collection of wastewater from individual properties and conveyance through a pressurised system to a treatment facility or other point of discharge.

Pressure Sewer Pumping Unit

The entire pumping system including the Pressure Sewer Collection Tank, Grinder Pump, Control/Alarm Panel, and all other pump control, operation, and protective devices.

Property Black Water Line

A pipeline within the property boundary owned by the property owner, which conveys sewerage from toilet installations to a septic tank or other place of disposal.

Property Boundary Kit

The boundary kit consists of a reflux valve, flushing tee, and ball valve. It is located at the boundary of the property being served and is located in the Property Discharge Line The boundary kit is owned by the property owner.

Property Discharge Line

A pressure sewer line, located on private property that is owned by the property owner. It connects the Pressure Sewer Pumping Unit to the Isolation valve immediately outside the property boundary.

Property Grey Water Line

A pipeline within the property boundary owned by the property owner that conveys shower water, wash water, or other wastewater away from the building(s) separate from the House Drain.

House Drain A pipeline installed by a licensed plumber, in accordance with plumbing code standards, within the property boundary and operated by a property owner that conveys sewage (grey and black water) from the building(s) to the Pressure Sewer Pumping Unit.


Part A




Property Service Line

A pressure sewer line, generally located on public property that is owned and operated by QUU. It connects the Pressure Sewer Network, located on public property, to the property isolation valve outside the property being serviced.

Property Sewer Service Diagram

A Plan drawing required for the data collection, design, construction, and recording of the pressure sewer system components located on private property. The diagram indicates the location of existing sewer system components as well as all new pressure sewer system components.

Pump Control/Power Cable

This cable delivers power from the Control/Alarm Panel to the Grinder Pump located within the Pressure Sewer Collection Tank, and transmits control signals between the Panel and the Pump.

Residual Volume The volume within the Pressure Sewer Collection Tank below the pump off level. This is the volume that remains in the tank after a normal pumping cycle is complete.

WSAA Codes The Codes produced by the Water Services Association of Australia. For the purpose of this document any reference to the Sewerage Code of Australia or the Water Supply Code of Australia.


Part A




2 DESIGN

2.1 GENERAL

In the design of a pressure sewer system, a significant amount of the system, critical to the operation, actually takes place on the individual homeowner's private properties. This increases the level of detailed on-site information needed to complete the design of the system. It is necessary to consider the operational involvement associated with accessing, maintaining and repairing the on-site components to ensure a continually reliable system. These circumstances warrant a system of the highest quality that balances cost, performance, safety, customer satisfaction, and operational reliability. The purpose of this document is to define minimum requirements for the on-property components of a pressure sewer system to ensure that this balance is met.

This document provides guidelines for locating the system components on the individual properties. It is intended to be used as an aid in the design, layout, and construction procedures associated with the implementation of a Low Pressure Sewer System.

The detailed design of low pressure sewer system including all “on-property” and pressure sewer network components shall be undertaken and certified by a manufacturer/supplier of a low pressure sewer pumps. The design calculations for the system shall be supplied to QUU for review and approval.

2.2 ADMINISTRATIVE PROCEDURES

Define procedures in place regarding Pressure Sewer System implementation:

(a) Project Delivery Strategy

(b) Product Procurement

(c) Limits of responsibility for QUU and Property owner(s) and/or occupier(s).

(d) Community Consultation

(e) Homeowner Interface

(f) Reviews, Approvals, and Acceptance procedures

2.3 DESIGN CONSIDERATIONS

2.3.1 The designer shall produce a Property Sewer Service Diagram for every property being served by the Pressure Sewer System. This diagram shall be used for the following purposes:

(a) Property data collection record.

(b) Design of on-property, Pressure Sewer System, and Layout

(c) Work-as-Executed record.

2.3.2 The data collection version, Design version, and the work-as-constructed version of the Property Sewer Service Diagram shall be submitted to QUU, prior to final acceptance of the system for operation, in hardcopy and electronic formats.


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The final locations and elevations of the on-property components shall be determined to the following level of design accuracy and specified accordingly in the Property Sewer Service Diagram:

(a) In horizontal, or plan, alignment:

1. To 0.1 m.

2. Shall be referenced to the MGA system and to local surveyed property boundaries.

(b) In vertical, or profile, alignment:

1. To 0.05 m where deviations to standard depth occur, where other services or obstructions are encountered, and for proximity to other general site features.

2. Shall be referenced the AHD.

2.3.3 Minimum horizontal clearance between underground water lines and any Pressure Sewer System component containing or transporting sewage shall be 300 mm. Where the crossing of an underground water line is required, the Property Discharge or Service Line shall be routed below the water line with a minimum vertical clearance of 100 mm. The preferred crossing angle is 90 degrees.

2.3.4 Installation methods and procedures shall generally comply with WSAA Codes of Practice WSA 02-2002 & WSA 03-2002, AS2566.2 and the guidelines outlined in this document.

2.3.5 All system pipelines including Property Discharge lines shall be PE100. This does not include pipelines associated with the grinder pump unit.

2.3.6 No equipment or materials are to be installed on vacant lots. A properly formatted Property Sewer Service Diagram fulfilling the requirements of this document shall be prepared and submitted to QUU for records, prior to connection of a previously vacant lot to the system.

2.3.7 Property owners, as well as any tenants, shall be identified for every property to be served, and kept informed of the project progress. All property related documents requiring approval or signature shall be presented to, and signed by, the property owner.

2.4 EXISTING PROPERTY DATA COLLECTION

The following data shall be collected in the field during the property inspection and documented on the Property Sewer Service Diagram:

1. Lot number, street name, and suburb.

2. Property Owners and Tenants (if applicable).

3. Property access issues such as fencing, gates, and animals.

4. Building outlines –Based on aerial photography, or survey data.

5. List of building plumbing facilities for buildings other than residential.


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6. Any excessive discharge fixtures, such as pools or spas.

7. Driveways, concrete footpaths, patios, decks, landscaping, fencing, and any other significant potential obstructions to the location or alignment of the Pressure Sewer System components, or the new House Drain.

8. Layout of all House Drains (including grey and black water lines).

9. Depth, and material, of each House Drain at building perimeter and at septic tank (if known).

10. The location of any storm water conveyance systems or drains / sub-surface drains including their point of discharge.

11. Septic tank(s) location, dimensioned from two known fixed points.

12. Electrical Distribution Box, shown in its actual location.

13. Any restoration considerations on the property as discussed with the property owner.

14. Underground services (if known).

15. Geological formations, such as rock, at less than 1 metre depth (if known).

16. Steep, difficult grade or particularly rugged terrain.

17. Significant vegetation.

2.5 DESIGN AND LAYOUT OF NEW ON-PROPERTY COMPONENTS

2.5.1 General

(a) The following factors shall be considered prior to locating any on-property Pressure Sewer System components, listed in descending order of priority:

1. Avoid impact on structure foundations and other property assets.

2. Allow for access of ongoing Operation and Maintenance of equipment being installed. Generally, access to the pressure sewer pumping unit by a 900 mm wide trolley, or safe and adequate walking access to that and all other on-property components.

3. Minimise encroachment of equipment on property.

4. Equipment shall be located to minimise the extent, and associated cost, of new infrastructure.

5. Minimise the length of property sewer pipe to be installed to minimise potential for infiltration and to minimise the property owner’s connection expense.

6. Any preferential locations requested by the property owner, which result in additional infrastructure, must be submitted to Council Plumbing Section for approval.

7. Where there is no viable alternative, consideration will be given to location of the holding tank and pump installation within the existing


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septic tank or in the location occupied by that septic tank. Costs such as tank clean out, decommissioning and sludge disposal will be the owners’ responsibility.

(b) The design of the LP sewer system including pressure mains and associated components shall be undertaken by a Registered Professional Engineer of Queensland (RPEQ) with a minimum of 3 years continuous experience with the design and installation of Low Pressure sewer systems.

The Engineer shall certify that the works have been designed and installed in accordance with approved plans and manufacture’s specifications to ensure that the system will perform satisfactorily.

2.5.2 Pressure Sewer Pumping Unit

(a) The Grinder Pump(s) shall have a capacity sufficient to accommodate the design peak flow for the property being served. QUU has standardised that an approved pump shall operate over the range set out on the pump curve shown below.

(b) The Pressure Sewer Collection Tank shall be designed to provide a minimum of 24 hours of emergency storage at the Average Dry Weather Flow for the property being served.

Pump Curve - Acceptable Range

0

5

10

15

20

25

30

35

40

45

50

0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8

Flow (l/s)

Head

(m

etr

e)


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(c) The pump shall preferably be located within 3 metres of the panel for operational issues.

(d) Special design consideration shall be given to properties with non-typical flow patterns, such as residences with additional or special features, commercial properties, schools, hospitals, etc:

1. Flow, backwash or other discharges from a pool or spa shall not be discharged to the Pressure Sewer Collection Tank nor the sewer network.

2. Where it may be necessary to install multiple units and/or greater storage capacity, the installation shall be specifically designed to take into account property water consumption, number of fixture units and the likely peak discharge rate.

3. Any opening on the Pressure Sewer Collection Tank shall be a minimum of 300mm above the 1-in-100 year flood level.

4. The Pressure Sewer Pumping Unit shall be installed in a location and at a depth that facilitates the collection of every House Drain serving the building(s) on the site. Where possible gully traps shall be at a level slightly lower than the Collection tank lid to provide a dedicated point of relief.

5. The Pressure Sewer Pumping Unit shall be installed with a minimum separation of:

a. 2 metres from building walls or other structures (including retaining walls) to clear the “45 degree zone of influence” on the foundation (for a 2000 mm pressure sewer collection tank depth).

b. 1.5 metres from opening windows.

c. 1.5 metres from the side boundary of the property.

d. Both present and proposed building lines (where plans have been submitted to Council for approval) shall be considered.

6. For deeper, non-standard, Pressure Sewer Pumping Unit installations separation from buildings and other structures will be required to clear the “45 degree zone of influence” on the foundation.

7. The Pressure Sewer Pumping Unit cover shall have a maintenance area with a minimum 1 metre clearance all around the outer circumference of the collection tank for at least 270 degrees on plan, with a 2.5 metres clear head height.

8. Above ground installations of Pressure Sewer Pumping Units are subject to approval from the Council Plumbing Section. Such installations i.e. under decking or a pole foundation shall consider a winching point with a load capacity for grinder pump removal. A maintenance area around and above the units shall also considered.

9. The Pressure Sewer Pumping Unit shall be located in an aesthetically


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pleasing location, clear of trafficable areas (pedestrian and vehicle) to avoid trip hazards and damage to the collection tank lid and walls. It shall also be located clear of areas where it is obvious that future building extensions could be made, or where the property owner signifies an intention to make additions to the residence.

10. The Pressure Sewer Pumping Unit shall be installed clear of local ground depressions and areas which tend to flood during inclement weather. If such installation cannot be avoided, the supplied tank vent shall be sealed and a new vent point shall be positioned near the top of the tank sidewall with a vent pipe routed to the building wall and up to a vent point above the existing roofline, in accordance with AS 3500.

11. The Pressure Sewer Pumping Unit shall not be located within buildings or other enclosed areas.

12. An educt vent shall be attached to the Pressure Sewer Collection Tank.

(e) For existing houses with septic tanks, wherever possible, the Pressure Sewer Pumping Unit shall be installed:

(i). to align with a side boundary between the building being served and the septic tank, and

(ii). as near as possible to the existing house drain.

Refer Clause 6 of Part A Typical On-Property Layout for a plan detail.

2.5.3 House Drain

Design and installation of the House Drain shall be in accordance with AS 3500.

2.5.4 Property Discharge and Service Line

(a) The Property Discharge and Service Lines shall be sized to provide a minimum velocity of 1 m/s to ensure sufficient scouring during a pumping cycle, and also consider minimising the friction losses through the pipe to conserve available pump head.

(b) For single Pressure Sewer Pumping Units, the property discharge and service line sizes shall be ≥ DN40 (OD of PE100 pipes).

(c) For duplex Pressure Sewer Pumping Units, the property discharge and service line sizes shall be ≥ DN50 (OD of PE100 pipes).

(d) For all other, non-standard Pressure Sewer Pumping Units, the line sizing shall be evaluated on a case-by-case basis and shall accomplish minimum scour velocity of 1 metres/sec while minimising friction losses.

(e) Only Polyethylene piping with minimum class of PE100 PN16 shall be used for the Property Discharge Line, Property Service Line, and all pipes within the Pressure Sewer Network. The PE pipe colour shall be:

• Internal: Optional—preferred white or light.

• External: Cream—solid or striped is acceptable.


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(f) All piping, fittings, and appurtenances shall be supplied, joined, and installed in accordance with the manufacturer’s recommendations by accredited installers and to Council Plumbing Section’s requirements.

(g) Sections of the piping with cuts or gouges exceeding 10 percent of the pipe wall thickness, or kinked sections, shall be removed and the ends rejoined.

(h) PE piping installed by trenching methods shall be joined using electro-fusion fittings. PE piping installed by horizontal directional drilling methods shall refer manufacture’s requirements otherwise shall not be joined.

(i) The use of 90-degree bends is permitted unless the fitting is a long radius bend with a minimum radius of 25 times pipe OD. All other 90-degree bends shall be accomplished by installing two 45-degree bends with a separation of 300 mm.

(j) The Property Discharge Line for a given property shall not cross onto any adjacent private property, or collect the discharge from any other property, unless all easement conditions are met and approved by Council. Exceptions may include special properties where the access drive for a given property serves as access to additional properties as well. Approval by QUU will also be required for these exceptions.

(k) The Property Discharge and Service Lines shall where possible be installed within a distance of 1.0 metre from the side boundary, beginning as near as possible to the installed location of the Pressure Sewer Pumping Unit and ending at the property boundary crossing, unless site conditions dictate a larger offset.

(l) The Property Discharge Line shall be offset from buildings at the required distance to clear the 45 degree zone of influence on the foundation.

(m) Minimum ground cover shall be in accordance with the attached “Minimum Pipe Cover” table. If circumstances are encountered that require installation at depths less than that specified in the referenced table, protective measures must be provided for, and approved by Council.

(n) The Property Service Line, between the Property Boundary Kit and the Pressure Sewer Network, shall be laid perpendicular to the Pressure Sewer Network.

2.5.5 Property Boundary Kit

(a) The Property Boundary Kit shall contain a pressure sewer specific SS/brass check valve, a SS/brass flushing tee, a solid SS/brass full bore shut-off ball valve (all minimum 32 mm ID) installed respectively in the direction of flow, in an access box, approved by Council Plumbing Section. All components of the Boundary Kit shall be suitable for use in sewage applications.

(b) The preferred Property Boundary Kit location is 1.0 metre inside the property line that parallels the Pressure Sewer Network, and 1.0 metre inside the nearest side property line, unless obstructions or other site conditions dictate another location. The intention of this location is to facilitate their use by service personnel, without undue search and entry into properties.

2.5.6 Control/Alarm Panel


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(a) All Control/Alarm Panels shall be complete with an Emergency generator connection point.

(b) The Control/Alarm Panel and Emergency generator connection point shall be mounted on the building being serviced by the Pressure Sewer System. An exception is where the pressure sewer pumping unit installation is required to be located more than 12 metres from the building being serviced and there is no other structure upon which to attach the panel. In this instance the panel must be mounted on a structurally sound post, meeting all regulation and code requirements.

(c) The Control/Alarm Panel shall be located in a safe area, within line of site of the Pressure Sewer Pumping Unit, and shall be positioned in a location such that visible and audible alarms will be noticed should an alarm condition occur.

(d) The Control/Alarm panel shall be mounted at a height of between 1200 and 1500 mm above ground level, and clear of the 1-in-100 year (average return interval) flood level.

2.6 THE WORK AS CONSTRUCTED PROPERTY SEWER SERVICE DIAGRAMS SHALL INCLUDE:

2.6.1 For existing properties the existing property data listed in Clause 2.4 of Part A.

2.6.2 Property Lines.

2.6.3 Roadways.

2.6.4 Easements.

2.6.5 North arrow and scale.

2.6.6 Pressure Sewer Pumping Unit location:

Dimensioned from at least two fixed points.

2.6.7 Pressure Sewer Pumping Unit manufacturer and model number.

2.6.8 Approximate locations of all connection points to existing House Drains.

2.6.9 Layout of new House Drain(s).

2.6.10 Layout of new Property Discharge Line and Property Service Line:

(a) Dimensioned from the nearest building and/or property line.

(b) All fittings used to accomplish bends shall be located on the plans and dimensioned from at least two fixed points.

(c) Elevations that deviate from standard depth shall be noted.

2.6.11 Location of Property Boundary Kit.

(a) Dimensioned from the nearest two adjacent property lines.

(b) Elevations that deviate from standard depth shall be noted.


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2.6.12 Show location of Property Service Line, isolation valve which is the point of connection to Pressure Sewer Network Main.

2.6.13 Location of Control/Alarm Panel:

Dimensioned from at least one building corner.

2.6.14 Layout of Electrical Cable routed from the Electrical Distribution Box to the Control/Alarm Panel.

2.6.15 Layout of the Pump Control Cable from the Control/Alarm Panel to the Pressure Sewer Pumping Unit.

2.6.16 Property asset number for the Pressure Sewer Pumping Unit shall be recorded on the Property Sewer Service Diagram.


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3 CONSTRUCTION

3.1 PRESSURE SEWER PUMPING UNIT

3.1.1 The Pressure Sewer Pumping Unit shall be installed in accordance with the manufacturers recommended installation instructions and Council Plumbing Section’s requirements.

3.1.2 The Tank must be handled with care to insure that no damage occurs during the shipping, unloading, storing, or installation process.

3.1.3 The Tank shall be filled, up to the inlet pipe invert level, with water prior to pouring the concrete anchor to prevent the tank from “floating” before the concrete sets.

3.1.4 Final ground level shall slope gradually away from the Tank to prevent storm water from collecting around the Tank.

3.1.5 For existing houses:

(a). Access to each property for property owner shall be maintained at all times during construction.

(b). Existing House Drain shall be exposed prior to installing the Pressure Sewer Collection Tank. Levels of the existing house drain shall be confirmed to ensure that all drains are collected. The Pressure Sewer Collection Tank shall be located at a level that permits sufficient slope on the new House Drain.

3.2 ELECTRICAL AND CONTROL EQUIPMENT

3.2.1 Control/Alarm Panel

(a) Installation shall be in accordance with all applicable codes, regulations and manufacture’s requirements.

(b) Connection to the panel shall be through the bottom of the panel and shall be glanded, to ensure a waterproof panel, and prevent moisture access into the panel. The conduit shall not extend into the panel. The cable shall extend into the panel and have a compression gland installed inside the panel.

3.2.2 Electrical and Pump Control Cable

All exposed and buried electrical and pump control cable shall be routed through a protective conduit and installed in accordance with all applicable codes, regulations and manufacture’s requirements.

3.3 PIPING AND ASSOCIATED COMPONENTS

3.3.1 House Drain:

The new House Drain shall be installed in accordance with AS 3500.

3.3.2 Property Discharge Line and Property Service Line:

(a) The Property Discharge Line and Property Service Line shall be constructed by either open trench construction or horizontal directional drilling to the


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minimum cover requirements specified in Table 3.4 and Clause 3.7 of AS/NZS 3500.2.

(b) To accommodate differential settlement between the Pressure Sewer Pumping Unit and the Property Discharge Line, two 45 degree bends shall be installed in the discharge line near the unit. The first socketed joint shall be installed 300 mm from the pipe connection fitting on the Collection Tank. The second socketed joint shall be installed in the same horizontal plane, 300 mm from the first.

(c) Property Discharge and Service Lines installed by horizontal directional drilling methods shall be installed with 316 SS tracer wire, and shall be tracked at the entry point, at the exit point, and at a maximum of 10 metre intervals in-between. Horizontal location and elevation shall be documented at each point.

(d) Property Discharge and Service Lines installed by open trenching methods shall use detectable marking tape with a 316 stainless steel tracer wire. The tape will be placed in the trench on top of the embedment material. Bare wires from the tape are to be connected to a bolt and located in a surface box. The tape shall be coloured cream and include the warning message in 40mm high letters “Caution Pressure Sewer Line Below”

(e) Termination points for the tracer wire shall be located at the Pressure Sewer Pumping Unit, and in the Property Boundary Kit.

(f) Where underground obstructions are encountered that require the line to be installed at less than minimum depth, protective measures shall be utilized in order to prevent damage to the piping upon the completion of construction. The protective method shall be approved by and in consultation with Council Plumbing Section prior to installation. Methods such as installing rigid casing pipe or protective plastic stripping may be considered.

3.4 INSPECTION, COMMISSIONING, TESTING, AND ACCEPTANCE

3.4.1 General

All installations for new or existing houses shall be inspected and accepted (including final inspection and acceptance) by Council Plumbing Section.

3.4.2 Property Discharge Line:

The Property Discharge Line shall be hydrostatically pressure tested. The test shall be in accordance with WSA 01-2004, including Pre-Testing Procedure and Basic Pressure Test, except that the test pressure shall be 1,200 KPa. If the hydrostatic test fails, the line shall be repaired/reinstalled and retested.

3.4.3 Pressure Sewer Pumping Unit:

The manufacturers recommended start-up and commissioning procedure must be completed by personnel able to carry out such work (certified by the manufacturer) in accordance with manufacturers warranty conditions, for acceptance by Council Plumbing Section.

3.4.4 House Drain(s):


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Upon installation of a new House Drain, the entire line between the house and the Pressure Sewer Pumping Unit shall be hydrostatically tested (for infiltration potential) in accordance with Council Plumbing Section’s requirements. If the hydrostatic test fails, the line shall be repaired/reinstalled and retested.

3.4.5 Requirements for installation on existing houses:

(a) Inspect existing Electrical Distribution Box. If existing Electrical Distribution Box does not meet relevant Australian Standards and Electrical Authority requirements, it shall be upgraded or replaced, as required, by the property owner prior to proceeding with any further electrical installation work on-site.

(b) Connect to existing Electrical Distribution Box with a separate electrical circuit and breaker.

(c) Existing House Drain shall be inspected and tested for potential storm water and sub-surface drain connections (wet weather inflow potential) prior to connecting to new House drain. Any such connections shall be disconnected and re-routed in accordance with AS/NZS3500.

(d) All existing gully traps shall be inspected and, if not comply with AS/NZS3500, relocated in accordance with the standard.

(e) Connect to existing House Drain in accordance with AS/NZS3500 and Council Plumbing Section’s requirements.

3.5 ASSET TRACKING AND MANAGEMENT DOCUMENTATION

3.5.1 Define format for tracking of equipment installed under construction contract.

3.5.2 Define information to be documented, such as:

(a) Property identification number.

(b) Property owner and tenant contact information.

(c) Special property condition per section 2.5.2 (d).

(d) Pressure Sewer Pumping Unit manufacturer and model number.

(e) Grinder Pump serial number.

(f) Pressure Sewer Collection Tank installation date.

(g) Grinder pump installation date.

(h) Pressure Sewer Pumping Unit commission date.

(i) Projected date of manufacturer’s warranty termination.

(j) Date of Homeowner Manual issue.

3.5.3 Asset Tracking and Management documents shall be submitted to Council upon the completion of construction.


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4 OPERATION AND MAINTENANCE

4.1 OPERATION

The on-property component of the low pressure sewer system consists of the House Drain, the pumping unit (collection tank, grinder pump, control panel and other pump control associated components), the property discharge line and the boundary kit up to but not including the property isolation valve. All the on-property components are owned, operated and maintained by the property owner.

The sewage from a property gravitates via House Drain to the collection tank supplied as part of the Pressure Sewer Pumping Unit that is installed on the individual property being served by the pressure sewer system. The tank collects the sewage discharged from the buildings being served and stored until the control system activates the grinder pump and the sewage is discharged from the tank via the property discharge line.

The boundary kit serves as a means of shutting-off the on-property components of the Pressure Sewer System from the utility components. It consists of a non-return valve, flushing tee, and ball shut-off valve. It is generally located inside the boundary of the property being served and is located in the Property Discharge Line.

The property isolation valve located immediately outside property line provides a means of isolation for Queensland Urban Utilities. The interface between utility’s sewer and the property owner’s sewer is located at the connection between the property isolation valve and the boundary kit. Refer to Drawing 486/5/25-S201.

4.2 MAINTENANCE

Pump system suppliers shall provide pre-assembled packages of low pressure sewer on-property components, including pump, collection tank, associated piping and valves, liquid level sensors, electrical control panel, electrical distribution box, and all other associated components.

A pre-assembled package has distinct advantage that the assembly has been refined, as dictated by previous experience. The pre-assembled package also provides a single source of responsibility in the event of malfunction and for components replacement.

Upon the completion of on property components installation:

(a) The pump system supplier shall provide develop/property owner with a service/maintenance plan covering both mechanical and electrical components.

(b) The pump system supplier shall provide developer/property owner with copies of electrical design/installation plans.

These plans may be provided as a part of the property owner’s manual.

5 STANDARD DOCUMENTS

WSA – 01 Polyethylene Pipeline Code WSA – 02 Sewerage Code of Australia

WSA – 03 Water Supply Code of Australia WSA – 07 Pressure Sewerage Code


Part A




6 TYPICAL PLAN OF ON-PROPERTY COMPONENTS

Figure 1 – New Development

E lectrica l cable

P roperty boundary kit

House dra in

E lectrica l d istribution box

P um p control c ab le

Collec tion tank / Pumping unit)

Control /a larm panel

Pressure sewer network

Property d isc harge l ine

Front lo t boundary

Connection to pres sure sewer network

Property servic e l ine

P ress ure s ewer

s ystem

Road reserve

P roperty isolation valve

x

Figure 2 – Existing House with Septic Tank

Existing septic tank

Electr ica l cable

Property boundary ki t

Existing house drain

Electr ica l distribution box

New customer house drain

Pump control c able

Press ure sewer collection tank

(conta ins the Grinder Pump)

Contro l/alar m panel

Press ure S ewer Networ k

Property discharge li ne

Front lo t boundary

Connection to press ure mainProperty servic e line

Press ure sewer pumping uni t

Existing grey water l ine

Pressure sewer

system

Road reserve

Property is ola tion valve

x


Part A




7 PIPE COVER REQUIREMENTS

Minimum Cover for Buried Low Pressure PE Pipelines inside the property

Location Minimum depth of cover, mm

Where subject to heavy vehicular traffic 500

Where subject to light vehicular traffic 450

Where not subject to vehicular loads 300

Refer Clause 3.7 of AS/NZS3500.2 for details.


Part B




PART B - NETWORK COMPONENTS – LOW PRESSURE SEWERS

Glossary: System Components

Property

Isolation Valve

The Property Isolation valve is located on public property immediately outside the private property being serviced. It serves to connect the property discharge line to the property service line and isolates the private property sewer components from the QUU network.

Pressure Sewer Network

The principal collection network in a Pressure Sewer System, consisting of small diameter pipelines and ancillary works, excluding the last upstream section located on the individual properties served by the system. The Pressure Sewer Network is owned and operated by QUU, for the collection of wastewater from individual properties and conveyance through a pressurised system to a treatment facility or other point of discharge.

Pressure Sewer Collection Tank

The collection tank supplied as part of the Pressure Sewer Pumping Unit that is installed on the individual property being served by the Pressure Sewer System

Pressure Sewer Pumping Unit

The entire pumping system including the Pressure Sewer Collection Tank, Grinder Pump, Control/Alarm Panel, and all other pump control, operation, and protective devices.

Pressure Sewer System

Covers the “on-property” installation and pressure sewer network.

Property Sewer Service Diagram

A Plan drawing required for the data collection, design, construction, and recording of the pressure sewer system components located on private property. The diagram indicates the location of existing sewer system components as well as all new pressure sewer system components.

Property Boundary Kit

The boundary kit consists of a check valve, flushing tee, and ball valve. It is generally located at the boundary of the property being serviced and is located in the Property Discharge Line The boundary kit is owned by the property owner.

Property Service Line

A pressure sewer line, generally located on public property that is owned and operated by QUU. It connects the Pressure Sewer Network, located on public property, to the property isolation valve located immediately outside the property being serviced.

Roadway Isolation Valve

The Roadway isolation valve serves to isolate the section of the property service line across the road from the remainder of QUU’s sewer network.

WSAA Codes The Codes produced by the Water Services Association of Australia. For the purpose of this document any reference to the Codes needs to refer to relevant QUU Supplementary Manual.


Part B




1. LOCATION OF NETWORK PIPES AND FITTINGS

This document is to be read in conjunction with Part A “On Property Components” and provides guidelines for locating the system components outside the property. It is to be used as an aid in the design, layout, and construction procedures associated with the implementation of a Pressure Sewer System network.

1.1 NETWORK MAINS

The network mains shall be placed in QUU’s footpath services allocation at an alignment as indicated on “City Assets” standard drawings No’s. UMS 121 to 124 for Brisbane, or equivalent elsewhere.

The designer should consider the following when determining the most appropriate location for the main:-

• Avoid locating the main on the same side as water mains or other significant buried infrastructure.

• Avoid slip and unstable areas.

• Distances from other services shall be in accordance with Table 3.1 of the Pressure Sewerage Code of Australia 07-2007.

• Services shall cross at 90 degrees if practical, but not less than 45 degrees.

Network Mains will achieve any bend greater than 45 degrees by use of multiple bends or a long radius bend as permitted by the Polyethylene Pipeline Code WSA 01-2004, where the minimum radius for cold bending is 25 times pipe OD. Bends are not to be achieved by utilising multiple butt welds.

1.2 ISOLATION VALVES

Isolation valves greater than or equal to DN 80 shall be line sized resilient seated gate valves or smaller than that shall be resilient seated ball valves per section 4.3.

Isolation valves shall be located:

• Where the property service line crosses the roadway, to isolate the section of property service line across the road from the QUU’s network.

• At the end of the property discharge line, immediately outside the property being served. This serves as the connection between the property discharge line and the property service line. Refer drawing 486/5/25-S201.

• At the incoming reticulation pressure main, i.e. at Tee’s.

• At intervals of not greater than 500 m or 30 service connections, whichever is the lesser.

• At both ends of bridge crossing.

• At both sides of areas of unstable ground.

• Immediately upstream of the discharge MH at the connection to the gravity sewer.


Part B




• At other positions on the network mains to provide operational flexibility for system operation, repair, line flushing and the like.

These requirements will necessitate the installation of two isolation valves where a property service line that crosses a roadway.

1.3 VACANT LOTS

Vacant lots shall be provided with Property Service Lines at the time of construction of the reticulation system. Property Service Lines shall be terminated at the end of the Property Isolation Valves and finished with a threaded or fusion bonded cap. Property Isolation Valves shall be located immediately outside the front property boundary line.

The location of Property Isolation Valves shall be identified with detectable marking tape secured to the last fitting and terminated above ground.

For large vacant lots or lots likely to be further subdivided or zoned for multi-housing or multi-unit or commercial or industrial development, Property Service Lines shall not be installed.

1.4 FLUSHING POINTS AND SCOURS

All dead end mains are to have an End Flushing facility provided.

Consideration shall be given to the installation of In Line Flushing facilities:

• Downstream of isolating valves except where there is a downstream flushing point within 100 m.

• Where there is more than one upstream connecting line.

• At intervals not exceeding 500 metres.

Flushing facilities will be designed to allow for scouring/flushing with flow initiation from the end flushing facilities and progressively downstream via in line flushing points to the discharge end of the network. Sizing of flushing points will be to suit the pressure and volume of water required to be injected at the flushing point to generate the required scouring flow velocity in the main.

Consideration should be given to locating flushing points:-

• Upstream of features such as major road, rail or creek crossings,

• At low points in the system where line drainage might be possible,

• Where flow/pressure measurement may be required,

• Where sampling may be required.

Flushing points shall be located in pits with appropriate covers as shown in QUU Drg. No. 486/5/25-SB005. The size of the pit shall allow for adequate clearance around any part of the fitting (including sampling points) to the nearest part of the pit, to permit operation of the valve.


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1.5 SAMPLING POINTS

Sampling points shall be located:

• With inline flushing points.

• Upstream and downstream of odour/chemical dosing point.

• Where the pressure network discharges to a receiving gravity collection system.

1.6 AIR RELEASE/ANTI VACUUM VALVES (AIR VALVE)

Manual or automatic air release/anti vacuum valves shall be located at parts of the main where the designer considers air may accumulate over time. However, the design shall ensure that where possible the pressure sewer is designed to avoid the use of air valves.

In circumstances where air accumulation will cause significant impact on the system hydraulics an automatic air valve is to be installed. The designer is to determine where this situation occurs and take into account the additional depth of cover required to install an air valve.

Air Valves will be required where the system hydraulics indicates the potential for negative pressures of 1 atmosphere. However, where vacuum break valves are provided as part of the on property collection /pumping unit, the designer shall determine if additional anti vacuum valves are required on the network pipework and specify appropriate locations on the design drawings.

Air release valves used for water systems are not suitable for pressure sewers as they may block and malfunction.

1.7 PROVISIONS FOR FLOW METERS

Provision shall be made to measure flow in the main as a minimum after the last branch connection, just prior to discharge into the downstream receiving gravity collection system. Other locations for flow meter installation shall be by arrangement between QUU and the Designers at the time of design, to suit proposed programs of system performance data collection.

The flowmeter located to measure total system flow shall be of electromagnetic type, located in a concrete chamber with full line size between flanges and replacement spool piece. The non permanent strategically located branch flow meter/s shall be of Transit Time type, located in temporary or permanent pits where the unit can be clamped to the exterior of the main.

The position of any flowmeter shall take into account the required straight length of pipe upstream (minimum 10 diameters) and downstream (minimum 5 diameters) of the meter position, graded to ensure there is no air entrapment.

Other considerations shall be the source of power supply, method of data capture and downloading, and any need for telemetry.


Part B




2. DEPTH OF MAINS

The required cover for pressure sewer mains shall be:

DN63 – 180 600mm

>DN250 1000mm

The maximum depth shall not exceed 1.5m. Refer Clause 5.4.2 of QUU Water Supply Standards for details.

3. DISCHARGE MH’S

The pressure sewer main shall discharge to the gravity sewer through a discharge MH in accordance with the details on Drg. No.486/5/25 – SC006. Where the pressure mains discharge directly to a deep or a trunk sewer, the discharge MH may be required to comply with the details on Drg. No. 486/5/25 – SC005.

Discharge MH’s shall not be located on private property.

Discharge MH may not be required for a small pressure sewer system. Where pressure sewers directly discharge into gravity sewers, designer shall ensure the turbulence and sulphide generation potential to downstream gravity sewers meet the odour management strategy as described below.

3.1 DISCHARGE MH’S - ODOUR MANAGEMENT STRATEGY

The design of the pressure sewer system shall include an analysis of the odour generation potential. This analysis shall take into consideration the sewage detention times both within collection chamber and the pressure pipe lines.

Such analysis including calculations shall be submitted to QUU for review. The designer shall ensure that the sulphide generation potential in pressure sewer system that discharge to downstream gravity sewers is kept to a level that is unlikely to cause nuisance odour.

Where odour generation exceeding 5 ppm of H2S may occur, an odour management strategy shall be implemented. Such strategies shall be produced by the designer and may include the installation of an electrically operated absorption and oxidation unit. The proposed odour control facility shall be adequate to reduce the H2S levels to below 5ppm and be to the approval of QUU.

4. MATERIAL REQUIREMENTS

All materials used shall be QUU approved.

All materials are to be transported, handled and stored in accordance with the manufacturer's recommendations and in a manner that prevents damage or deterioration.

All products and materials are to be inspected at the time of delivery for damage and/or excessive distortion.

4.1 PIPE MATERIAL

The pipe material to be used for Network Pipework shall be PE100, PN16 (SDR11)


Part B




as a minimum. All fittings shall be fully moulded.

The PE pipe colour shall be:

• Internal: Optional—preferred white or light.

• External: Cream—solid or striped is acceptable.

The designer shall investigate availability of pipe and fitting sizes to ensure that future supplies are readily available in Australia.

Acceptable sizes of PN16 PE100 pipe and compatible electro-fusion fittings include: DN 40, 50, 63, 90, 125, 180, 250, 315, 355, 450, 630 and 800.

4.1.1 Pipe Materials for Horizontal Directional Drilling (HDD)

4.1.1.1 Pre-Construction Surveys (Dilapidation Survey)

Where bores traverse under or near structures, including roadways a pre construction survey is to be performed for this structure.

4.1.1.2 Selection of Pipe Class

Where HDD is the method of installation, the designer shall consider the following:-

• Pre-installation loads (e.g. hydrostatic test loads)

• Installation loads (e.g. maximum installation force on the product)

Where HDD is the method chosen for pipelaying and installation, the designer shall take into account the potential for pipe striations or notches to occur longitudinally in the exterior pipe wall as the pipe is pulled into the bored hole.

HDD installation shall only be used where specified by the designer and the designer is responsible for ensuring that the main is capable of being installed to the design drawings and within the specified tolerances.

The designer shall calculate the maximum tensile load permissible to be applied to the pipe during installation and provide these requirements to the Contractor. The pipe shall not be overstressed during installation.

4.1.1.3 Waterway Crossings

Waterway Crossings shall be in accordance with WAT-1211 of the Water Supply Code of Australia 2002.

4.2 JOINTING AND CLEANING

Acceptable joint types are electro-fusion, butt welding or restraint coupling. For pipe sizes less than DN63, compression type jointing may be used, though welding joints are preferred. All PE joints shall comply with AS/NZS 4129 and be rated PN16 as a minimum.

Transition between sizes shall be made using a tapered connection.

All welding shall be undertaken by trained and certified welders in accordance with WSA 01-2004 and the manufacturer’s welding requirements/recommendations.


Part B




Training courses shall be Plastic Industry Pipe Association (PIPA) approved.

Electro-fusion welding will not be permitted on lengths of PE pipe pulled through a HDD bore unless appropriate design for the coupling’s oversize & stress has been carried out.

4.3 ISOLATING VALVES

Isolating Valves greater than or equal to DN 80 shall be resilient seated gate valves, suitable for use in sewer environments and pressure rating of PN16 as a minimum complying with WSA PS-260. The end connection shall be flange, elector-fusion or restraint.

Isolating Valves less than DN 80 shall be resilient seated ball valves suitable for use in sewer environments and complying with WSA PS274. The specifier is to submit the recommended valve to QUU for acceptance prior to use.

Flanges for PE pipes shall be full face and be supplied by the pipe manufacturer to suit the pipe class of PN16 as a minimum. Flanges shall be attached to pipes by welding and have grade 316 stainless steel backing plates which comply with AS 2129 and grade 316 stainless steel bolts. The threads on all bolts and nuts shall be coated with anti-friction lubricant upon installation. Bolt tensioning shall be a two stage process with final tightening occurring prior to pressure testing of lines and a minimum of 12 hours after initial tightening.

Flange gaskets shall be 3mm thickness full face NBR or EPDM rubber with a Durometer hardness of 55 to 57 complying with WSA-109.

Isolating valves shall be buried, with surface fittings in accordance with QUU Drg No. 48/5/25–SB008. The exception being ball valves, which have spindles that only turn through 90 degrees, that shall have surface fittings which are either distinctively different, or are marked to indicate that spindle rotation is limited to 90 degree between the fully open and fully closed positions.

4.4 AIR VALVES

4.4.1 Manual Air Valves

Manual Air Valves will include use of a fusion coupling tee offtake from the main, similar to that used for Property Service Lines (Section 4.2). The manual air valve shall be located in a pit similar to those used for Flushing points. Adequate clearance around any part of the valve to the nearest point of the pit shall be provided to permit operation of the valve. The manual air valve will be no greater than DN25 and will have a discharge pipe facing the bottom of the pit. Refer to QUU drawing 486/5/25-SB006.

4.4.2 Automatic Air Release/Anti Vacuum Valves (Air Valves)

Automatic air valves shall be located in concrete chambers that provide adequate safe room for servicing/replacement of the air valve.

The chamber shall be vented appropriately so that any odour issues are minimised in the design. The chamber shall be adequately drained or sealed against infiltration.


Part B




5 CONSTRUCTION

5.1 PROTECTION OF SERVICES

The Designer is to ensure that all services within the area of work are shown on the Design Plans and the Contractor is to protect services in accordance with Clause 13.5.2 of WSA 07-2007.

5.2 CONNECTION TO SEWER NETWORK

Connection of Property Service Lines to network mains shall be achieved by the use of electro-fusion tees or saddles with reducer and coupler or similar arrangement, to make a 90 degree tee connection with the network main.

The designer should consider the use of slope connections where the hydraulic performance requires.

All connection fittings for air valves, scours and sampling points will be made using electro-fusion saddles or tees and reducers where required.

5.3 TYPE OF PITS AND COVERS

Pits and covers will be required for network mains to accommodate End or In-line flushing point, air valve, and flow meter installations similar to drawing 486/5/25-SB006.

5.4 PIPE EMBEDMENT MATERIAL

Pipe embedment shall be 5 to 7 mm single sized aggregates to WSA PS-351 or 14mm single sized recycled concrete complying with the WSA PS-366 and shall be compacted in accordance with WSA 03-2002.

5.5 TRENCH FILL

Trench fill materials and compaction shall comply with WSA 03-2002.

5.6 TOLERANCES

Tolerances for pipe placement shall comply with WSA 03-2002.

5.7 PRESSURE TESTING

Pressure testing shall be performed as follows:-

(a) All lines shall be hydrostatically pressure tested. The test shall be in accordance with WSA 01-2004 Polyethylene Pipeline Code including “pre-test procedures” and "Basic Pressure Test" per clause 2.13, with the exception that the test pressure shall be to a maximum of 120 metres head. The pressure shall be held over a minimum duration of 15 minutes duration to ensure adequate time to visually check for leakage at all joints and fittings. If the hydrostatic test fails, the line shall be repaired/reinstalled and retested. Alternatively the "General Pressure Test" may be used.

(b) Where Horizontal Directional Drilling techniques have been used, the pressure testing shall be in accordance with WSA 01-2004 “Polyethylene Pipe Code” "General Pressure Test" per clause 2.13.5 and to a maximum of


Part B




120 metres head.

5.8 MECHANICAL PROTECTION OF PIPELINE

Any mechanical method of protection will need QUU approval.

A pipeline constructed above ground, or under or near structures and major roadways, will required mechanical protection to minimise the need for future maintenance.

Acceptable methods of mechanical protection include:-

(a) Concrete encasement in accordance with WSA 03 2002, WAT-1204

(b) Grouting the pipeline within an encasing pipe in accordance with WSA 03 2002, WAT-1212 and WAT-1213.

For these methods are, where the concrete encasement finishes, there is to be a compressible membrane as detailed in AS 2566.2 Figure 5.6.

Mechanical protection is required for non standard shallow depth of pipelines.

5.9 PIPELINE TRACER WIRES AND TAPE

Property Service Lines and Network Mains installed by horizontal directional drilling methods (HDD) shall be installed with 316 SS braided tracer wire wrapped around the pipe, and shall be tracked at the entry point, at the exit point, and at a maximum of 10 metre intervals in between. Horizontal location and elevation shall be documented at each point.

Property Service Lines and Network Mains installed by open trenching methods shall use detectable marking tape with a 316 stainless steel tracer wire in accordance with WSAA Purchase Specification WSA - PS 318. The tape will be placed in the trench on top of the embedment material. Bare wires from the tape are to be connected to the next available termination feature.

Termination points for the tracer wire shall be located at in line fittings and features such as isolation valves, line flushing points, air valves and boundary valve kits, etc.

The tape shall include the warning message in 40mm high letters “Caution Pressure Sewer Line Below”

5.10 CONSTRUCTION BY HDD TECHNIQUES

5.10.1 Pre-Construction Surveys (Dilapidation Survey)

Where bores traverse under or near structures, including roadways a pre construction survey is to be performed for this structure.

5.10.2 Pipe Condition

Where notch depth is found to exceed 10% of pipe wall thickness at any point in the circumference of the pipe exterior after installation, the pipe shall be replaced with a pipe that provides equivalent wall thickness of original pipe plus the greatest depth of notch after the pipes installation.


Part B




Inspections of the pipe's exterior "scored" condition shall be undertaken periodically at the commencement of HDD operations in a location at least 1 metre clear of the winching nose cone, and from time to time where ground conditions are noted to be more susceptible to cause scoring to occur.

HDD installation shall be used where specified or otherwise approved by the designer, and the designer shall provide the maximum tensile stress allowable for the installation. The Constructor shall not exceed the tensile capacity of the pipe during installation.

After installation by HDD methods, the pipe will contract in length and is to be left unrestrained for a period of 24 hours, or such period that is observed to coincide with practical cessation of contraction.

5.10.3 Waterway Crossings

Waterway Crossings shall be in accordance with WAT-1211 of the Water Supply Code of Australia WSA 03-2002.

5.10.4 Grouting Requirements

In rock strata, where the bore diameter exceeds the product pipe outside diameter by more than 50mm, then the product pipe shall be grouted within the hole at each end for a minimum distance of 2 metres. The grout shall be designed to ensure minimal shrinkage and provide effective stoppage of water ingress between the pipe and the bore. In all cases where ground water is encountered or expected to be encountered, grouting or bulkheads shall be used at each end of the pipeline and where appropriate as a minimum to prevent groundwater movement along the length of the bore.

Where grouting at each end or bulkheading is not expected to be effective in preventing groundwater movement along the length of the bore, the designer shall specify the extent of grouting.

Where grouting occurs the transition from encased to non encased pipe shall be in accordance with AS 2566.2 Figure 5.6.

5.10.5 Drainage

Where open trench construction interfaces with HDD construction the designer is to ensure that the trench construction has adequate drainage to avoid water rising from the trench and causing seepage issues.

5.10.6 Squeeze Off

Where squeeze off techniques are used to isolate sections of pipework during construction, it will be performed using methods and equipment approved by the pipe manufacturer. On release of the squeeze:

a) Inspect and re-round the pipe if necessary.

b) Cut-out and renew the pipe if there is any indication of damage (e.g. cracking or splitting).

c) Weld an electro-fusion repair saddle or split coupling over the squeezed-off section to avoid any subsequent squeezing operation.


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5.11 WORK AS CONSTRUCTED DETAILS

A survey check shall be carried out to ensure that the location of components of the newly constructed low pressure sewer system, including pressure sewer mains, maintenance holes, valves, flushing points, pressure sewer service lines, branches, and bends etc, have been constructed in accordance with this Standard and the Design Drawings.

For pressure sewer mains and service lines, the embedment materials shall not be placed over the pipe joints and fittings until the “As-Constructed” survey has been completed.

The “As-Constructed” drawings shall include:

(a) The Asset Register Table for all components.

(b) The total length of pressure sewer mains for each pipe diameter.

(c) The number and the total length of each size of pressure sewer services.

(d) Ties to identify the location where reticulation mains intersect.

(e) The location of connections between network mains and pressure services by showing chainage from the nearest downstream intersection of reticulation mains.

(f) Depth where the depth deviates by more than 200mm from the minimum cover requirement.

(g) Regular offset for the pressure sewer mains from property boundary.

(h) The location of isolation valves, air valves and flush points by showing chainage from the nearest downstream intersection of mains.

(i) Construction start and completion dates.

(j) Any variations to the fitting list.

(k) The funding details, as per Asset Funding Text Block shown below. Asset Funding Text Block

ASSET REGISTER (Tick appropriate box)

QUU FUNDED DEVELOPER FUNDED

( ) COUNCIL FUNDED* STATE GOV’T FUNDED

FEDERAL GOV’T FUNDED OTHER


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“AS-CONSTRUCTED” – SIGHTED FUNDING INFORMATION COMPLETED.

SIGNED (Utility/Rep.) DATE

NAME OF SIGNATORY (Print)

* Fill the name of Council in bracket if Council funded.

All “As-Constructed” drawings shall have a text block as shown below which shall be signed by an RPEQ to certify that they represent a true record of the works.

RPEQ Certification Block

“AS-CONSTRUCTED” DETAILS

I CERTIFY THAT THE “AS-CONSTRUCTED” DETAILS SHOWN ON THIS PLAN ARE A TRUE AND ACCURATE RECORD OF THE WORKS SIGNED DATE

RPEQ No NAME OF SIGNATORY (PRINT) NAME OF COMPANY

On each occasion that “As-Constructed” drawings are submitted to the Utility or Utility Representative, one drawing shall include the audit trail block as shown on the right hand side of Drg. No. 486/5/25 – SG002.

QUU Low Pressure Sewers – 2011

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