Water Supply Reticulation Design and Construction
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Chapter 13 - Water Supply Reticulation - Design and Construction Table of Contents
Chapter 13:
WATER SUPPLY RETICULATION DESIGN AND CONSTRUCTION
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Chapter 13 - Water Supply Reticulation - Design and Construction Table of Contents
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WATER SUPPLY RETICULATION DESIGN AND CONSTRUCTION Table of Contents
Clause
Subject
13.1
GENERAL................................................................................................................. 13-1
13.1.1 13.1.2 13.1.3 13.1.4 13.1.5 13.1.6 13.1.7
General ..................................................................................................................... 13-1 Definitions ................................................................................................................. 13-1 Works Carried Out by Council .................................................................................. 13-1 Non Complying Works .............................................................................................. 13-2 Works Affected by Other Authorities......................................................................... 13-2 Site Safety................................................................................................................. 13-2 Works on Private Property........................................................................................ 13-2
13.2
MINES SUBSIDENCE .............................................................................................. 13-2
13.3
DRAWINGS GENERALLY ....................................................................................... 13-3
13.3.1 13.3.2
Plan Requirements ................................................................................................... 13-3 Work as Executed Drawings..................................................................................... 13-3
13.4
WATER DESIGN ...................................................................................................... 13-4
13.4.1 13.4.2 13.4.3 13.4.4 13.4.5 13.4.6 13.4.7 13.4.8 13.4.9 13.4.10 13.4.11 13.4.12 13.4.13 13.4.14 13.4.15 13.4.16 13.4.17 13.4.18 13.4.19 13.4.20 13.4.21 13.4.22 13.4.23 13.4.24
Locations................................................................................................................... 13-4 Datum ....................................................................................................................... 13-4 Reticulation mains..................................................................................................... 13-4 Service Mains ........................................................................................................... 13-5 Lot Servicing ............................................................................................................. 13-6 Cover Requirements - Reticulation Mains and Water Services ............................... 13-6 Fire Hydrant Spacings .............................................................................................. 13-6 Stop Valve Spacing................................................................................................... 13-7 Existing Mains........................................................................................................... 13-7 Steep Pipelines ......................................................................................................... 13-7 Trench Stops............................................................................................................. 13-7 Concrete Bulkheads.................................................................................................. 13-8 Thrust and Anchor Blocks......................................................................................... 13-8 Protection of Pipelines .............................................................................................. 13-8 Boring Under Existing Council Roads....................................................................... 13-9 Pipe Crossings - RTA or SRA Property .................................................................. 13-10 Encasing Under Trees ............................................................................................ 13-10 Main Marking .......................................................................................................... 13-10 Water Services........................................................................................................ 13-11 Alternative Materials ............................................................................................... 13-13 Water Service Testing ............................................................................................ 13-13 Service Marks ......................................................................................................... 13-13 Main Cocks Under Concrete Footpaths and Driveways......................................... 13-13 Landscape Irrigation ............................................................................................... 13-13
13.5
SUPPLY OF PIPES AND FITTINGS ...................................................................... 13-14
13.5.1 13.5.2 13.5.3 13.5.4
General ................................................................................................................... 13-14 Quality Assurance................................................................................................... 13-14 Certificate of Compliance........................................................................................ 13-14 Pipe Material ........................................................................................................... 13-15
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WATER SUPPLY RETICULATION DESIGN AND CONSTRUCTION Table of Contents (Continued)
Clause
Subject
13.5.5 13.5.6 13.5.7 13.5.8 13.5.9 13.5.10 13.5.11 13.5.12
Pipe Fittings: General ............................................................................................ 13-15 Alternative Pipe Material and Fittings ..................................................................... 13-15 Pipe Jointing Systems ............................................................................................ 13-16 Witness Marks ........................................................................................................ 13-16 Mine Subsidence Joints.......................................................................................... 13-17 Fasteners ................................................................................................................ 13-18 Fittings .................................................................................................................... 13-18 Handling and Storage ............................................................................................. 13-19
13.6
EARTHWORKS ...................................................................................................... 13-19
13.6.1 13.6.2 13.6.3 13.6.4 13.6.5 13.6.6
General ................................................................................................................... 13-19 Trench Width for All UPVC Pressure Pipelines ...................................................... 13-19 Excavation Depth.................................................................................................... 13-20 Extra Depth Excavation .......................................................................................... 13-20 Dewatering.............................................................................................................. 13-20 Support of Excavations ........................................................................................... 13-21
13.7
EROSION AND SEDIMENT CONTROL ................................................................ 13-21
13.8
PIPE BEDDING ...................................................................................................... 13-21
13.8.1 13.8.2 13.8.3
General ................................................................................................................... 13-21 Sand Bedding ......................................................................................................... 13-21 Granular Bedding.................................................................................................... 13-22
13.9
LAY AND JOINTING............................................................................................... 13-22
13.9.1 13.9.2 13.9.3 13.9.4 13.9.5 13.9.6 13.9.7 13.9.8
Installation Details - General................................................................................... 13-22 Pipe Grading and Alignment................................................................................... 13-23 Tolerances .............................................................................................................. 13-23 Reinstating Witness Marks ..................................................................................... 13-24 Cutting of Pipes....................................................................................................... 13-24 Pressure Pipeline Fittings ....................................................................................... 13-24 Polyethylene Wrapping of Pipelines and Fittings Ductile Iron ................................ 13-25 Main Damage.......................................................................................................... 13-25
13.10
BACKFILLING AND COMPACTION ...................................................................... 13-25
13.10.1 13.10.2 13.10.3
General ................................................................................................................... 13-25 Restoration.............................................................................................................. 13-26 Maintenance ........................................................................................................... 13-27
13.11
TESTING OF WATER MAINS AND SERVICES.................................................... 13-27
13.11.1 13.11.2 13.11.3 13.11.4 13.11.5
General ................................................................................................................... 13-27 Method of Carrying Out Test .................................................................................. 13-27 Allowable Leakage Tolerances............................................................................... 13-28 Repair of Leaks....................................................................................................... 13-28 Council Acceptance ................................................................................................ 13-29
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WATER SUPPLY RETICULATION - DESIGN AND CONSTRUCTION
13.1 13.1.1
GENERAL General This specification outlines the minimum requirements for the supply, delivery and the design and construction of water reticulation pipes, fittings and water services. This specification is intended to: 1
Outline all requirements for general development work; and
2
Form a Schedule to Specification (detailing technical requirements) to accompany specifications for Contractor constructed works.
All works are to be carried out in accordance with this specification, the regulations of the relevant statutory authorities and manufacturers recommended procedures where appropriate. 13.1.2
Definitions The term "The Engineer" shall refer to the Director of Engineering Services or the appointed representative. Refer Clause 2.3 for additional definitions.
13.1.3
Works Carried Out by Council Connections to Council's existing water reticulation system is to be carried out by Council where the execution of such work may result in the disruption or the reduction in the quality of the water supply or additional work to Council during the construction period. Where Council undertakes the connection, Council will generally provide and install a tee connection complete with a stop valve of the size and at the location nominated in the approved connection design. It will be the responsibility of the Developer to connect the main to this connection point following acceptance of the works in accordance with Clause 13.11.5 A design detailing all bends, fittings, valves etc. for connection/s and main adjustment works shall be prepared by the Developer. The design shall be submitted to the Engineer for approval a minimum of four (4) weeks prior to the works being required. At the Developers written request the Engineer shall provide estimated costs for work to be carried out by Council. No Developer supplied materials will be accepted by Council for use in the works. The payment is based upon an estimate only, actual costs will be charged to the Developer on completion of the works. Prepayment of the estimated amount will be required prior to Council ordering materials and programming works. The work will be commenced within twenty (20) working days from the date of receipt of payment, of delivery of material or upon written notification by the Developer to commence work whichever is later.
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In selected situations as determined by the Engineer work carried out by Council may be undertaken on a "do and charge" sundry debt basis. These situations will be restricted to minor works using stock material and requiring no design. These works will be completed within one (1) week upon notification of the Developer to commence work. The Developer is advised that several weeks lead time after payment may be required for the supply of non-stock materials. Council will not accept responsibility for any delays incurred by the Developer or their agents through their failure to obtain a timely quotation, make payment or make written notification for the connection works. 13.1.4
Non Complying Works Where work as executed levels, grades and alignments do not comply with the construction tolerances of Clause 13.9.3 the requirements of Clause 2.33 shall apply. Refer Clause 13.3.2 for Works as Executed requirements.
13.1.5
Works Affected by Other Authorities Where a pipeline or structure crosses, or is located within a main road, creek, or construction of the work affects plant, assets or property under the control of any other Authority, the work shall be carried out in accordance with the requirements of that Authority for such work. The Developer will obtain all necessary approvals and pay any associated fees and charges for the work from the Authority concerned. It will be the Developer's responsibility to notify the Authority of their intention to construct and to complete any written notification so required.
13.1.6
Site Safety The Developer shall comply with all relevant Occupational Health and Safety Regulations and exercise all necessary precautions for the safety of site personnel.
13.1.7
Works on Private Property The Developer shall arrange all necessary permits and agreements to facilitate works on private property.
13.2
MINES SUBSIDENCE The Developer is advised that parts of Wyong Shire fall within proclaimed Mine Subsidence areas. All pipe jointing systems for water reticulation works must be capable of accommodating movement associated with the mine subsidence design ground strain as advised by the Mine Subsidence Board for the nominated development area. It is the responsibility of the Developer to check if the proposed work lies within a proclaimed Mines Subsidence area and (if applicable) obtain the design ground strain for the associated development site from the Mine Subsidence Board for design of the works. The design ground strain is to be clearly detailed on the design drawings. In addition the relevant calculations (refer Clause 13.5.9), specific pipe type and length, joint type and socket
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Chapter 13 - Water Supply Reticulation - Design and Construction
depth, fitting type and socket depth shall be certified as complying by the manufacture. It will be the Developer's responsibility to ensure that any pipe jointing system supplied and incorporated with the works comply with the requirements of Clause 13.5.7 for the nominated design ground strain. Failure to comply with Mines Subsidence requirements shall result in a direction by the Engineer to remove all non-complying material. All costs associated with removal of the faulty work and supply of new pipe materials shall be borne by the Developer. For information regarding ground strains for Wyong Shire the Developer should contact the District Inspector, Mines Subsidence Board, Wyong. 13.3
DRAWINGS
13.3.1
Plan Requirements Drawings that are submitted for approval to the Engineer shall be prepared to the following scales: a
Detail Plans Scale
- 1:500 (or 1:1000 if previously approved by the Engineer)
b
Long Section Scale (where applicable)
- Vertical - 1:200 - Horizontal - 1:1000
All existing services, features and proposed works including water mains, sewers, electricity supplies, property of Telstra, stormwater pipes, kerb and gutter and any other services are to be shown on the plans. Longitudinal sections will generally be required for carrier and trunk mains, showing depth of cover, type and class of pipe, fittings, details of thrust blocks, trench stops or bulkheads and special bedding, and any vertical deviation from standard cover. All easements for water mains are to be arranged and finalised by the Developer. The details of relevant easements are to be shown on the design drawings. All tie dimensions to air valves and scours are to be shown in metres and parts thereof and are to be taken from corners of lots or other similar permanent marks. Ties to fence posts, trees and other impermanent or temporary structures are not permitted. 13.3.2
Work as Executed Drawings Work as executed drawings are required to be submitted to the Engineer by the Developer after completion of the works. The work as executed drawings will show, but not be limited to, the location and alignment of mains and fittings including the following details:
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a
Minimum of two ties to air valves in relation to lot boundaries or other permanent marks;
b
Minimum of two ties to scours in relation to lot boundaries or other permanent marks;
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c
The locations of hydrants, main cocks, stop valves, tees, tapers, dead ends, air and scour valves and water services and all lot boundaries and kerb lines.
d
The pipe sizes, class and type of material used, and the work as executed pipe grade and levels (where applicable).
e
Extent of concrete encasing or pipeline protection.
f
The pipe length between fittings and the straight line dimensions between hydrant and valves.
g
The distance of all mains from the adjacent boundaries.
Refer Drawing SD70 for an example of Works as Executed requirements. All "Work As Executed" drawings are to be certified by a Registered Surveyor and be submitted on copies of the originals for Council approval prior to the release of the linen plan. 13.4
WATER DESIGN
13.4.1
Locations Water mains are to be constructed and laid in the locations shown on the approved engineering plans. Water mains are to be laid within the allocations shown in all instances on Drawing SD 26A or, SD 25A where the Developer nominates shared trenching or shared trenching is a condition of Development Approval. Where significant vegetation is to be retained adjacent to the above alignments variations may be required subject to the Engineer's approval and the vegetation protection treatments of Chapter 3 shall apply.
13.4.2
Datum All levels shown on the drawings are to be to Australian Height Datum. The locations and reduced levels of the benchmarks used and origin of levels for the design are to be detailed on the drawings. Permanent, substantial and easily accessible bench marks are to be provided by the Developer and their location and level are to be clearly shown on the drawings.
13.4.3
Reticulation Mains a
All water supply reticulation mains are to be designed in accordance with the current Public Works Department of NSW, Water Supply Investigation Manual 1986 unless otherwise amended in this specification.
b
The minimum size for water mains shall be 100mm diameter in residential and rural developments. For industrial and commercial areas, a minimum 150mm diameter main is to be provided.
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c
The Developers attention is directed to Clause 13.4.1 regarding location of mains. Pipes laid adjacent to curved boundaries will not be permitted to be curved or bent along the axis of the pipeline between any flexible joints or connections unless the pipes are manufactured in curves and satisfy the requirements herein. Changes in direction are to be obtained using suitable bends or joint deflections in accordance with Clause 13.9.2. When approved by the Engineer the Developer may use continuous flexible medium density polyethylene pipe (MDPE) systems of equivalent classes. When other alternatives are proposed, full details are to be submitted to the Engineer for assessment. Refer Clause 13.5.6.
13.4.4
d
Looping of mains will be required to eliminate dead end lines. Looping of mains in cul-de-sacs is to be provided in accordance with Drawing SD16A.
e
The Developer's attention is drawn to Drawing SD 43A of this specification. Where at least one main is smaller than 200mm nominal size the location of tee junctions under roadways is to be avoided unless otherwise approved by the Engineer. Where both mains are 200mm nominal size and greater, tee junctions will be permitted in the roadway where necessary.
Service Mains All internal service mains are to be designed in accordance with the relevant Australian Standard referred to in the Building Code of Australia with adequate provision for the fire fighting services to the proposed development. The following table details the fire flows required under the Building Code of Australia. Class of Building
Fire Flow Required (L/S) 4.5
1
Single Dwelling - Houses
2
Office buildings, common residential buildings, including flats and boarding houses with buildings NOT EXCEEDING 25m in height.
11
3
As for 2 with buildings EXCEEDING 25m in height
22
4
Shops, restaurants, hotels, motels, markets, laundries, service stations, public garages, warehouses, factories, laboratories and institutions with buildings of: - 1 or 2 storeys; or - 3 or 4 storeys and total floor area NOT EXCEEDING 2,000m2
15
5
As for 4 with buildings of: - 3 or 4 storeys and total floor area EXCEEDING 2,000m2; or - 5 or more storeys
22
Flow rates are in accordance with the relevant Australian Standard as specified in the Building Code of Australia, and are as recommended in NSW Public Works Department Water Supply Investigation Manual, 1986.
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13.4.5
Lot Servicing Refer Clause 13.4.19 for detail requirements.
13.4.6
a
Every lot within the development shall be provided with an individual water service, servicing only that lot. Water services servicing more than one (1) lot (dual services) will not be permitted.
b
Water services shall only be connected into mains of a size equal to or greater than 100mm nominal size.
c
Refer to Drawing SD13 for water service location to battleaxe and multiple lots serviced via right of carriageway handles.
Cover Requirements - Reticulation Mains and Water Services a
Pipelines The minimum depth of cover to be provided for UPVC pressure pipelines as measured from the final design ground level to the top of the pipe barrel shall be as follows: Location of Pipe
UPVC
1 Areas not subject to vehicular loading 2 Areas potentially subject to vehicular loading*
500 750
*This includes construction traffic loading.
Lesser covers may be permitted subject to the approval of the Engineer where the pipes are laid in ductile iron or where special protection of the pipelines such as concrete encasing has been specified or directed by the Engineer. The Developer's attention is drawn to the fact that pipe cover adjacent to valves or other fittings may vary with varying pipe sizes. It is the Developer's responsibility to ensure that the correct depth for the pipeline is maintained at any fitting. b
Water Services Services are to be located a minimum depth of 150mm below the subgrade level or have a minimum 400mm cover below the crown of road whichever is the greater and a minimum of 300mm cover in footpaths. A maximum depth of up to 1.0m will generally apply.
13.4.7
Fire Hydrant Spacings Maximum hydrant spacing is to be 60 metres in residential areas. Spacing of up to 120 metres in rural areas will be permitted as long as all dwellings are adequately serviced. Notwithstanding the above, hydrants are required to be installed on the end of all dead end lines, either temporary or permanent, and at the high and low points of the main. All dead end hydrants are to be secured with an adequate thrust block located off line from the main to permit future extension if required.
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13.4.8
Stop Valve Spacing Stop valves within subdivisions shall be located at spacings such that no more than a total of fifty (50) residential allotments exist between any two (2) stop valves located on the same distribution main. Notwithstanding the above, stop valves wherever possible shall be located at street corners or immediately downstream of off-take line interconnections within the footpath area in accordance within drawing SD 43.
13.4.9
Existing Mains If hydrants or stop valves on existing lines are of inadequate spacing, additional hydrants or stop valves will be required to be installed to satisfy the requirements of Clauses 13.4.7 and 13.4.8 at the Developer's expense.
13.4.10 Steep Pipelines a
Where pipelines are laid on grades of 25 percent or greater the provision of concrete bedding in accordance with Drawing SD 37C will be required to ensure that movement of the pipeline during construction does not occur.
b
Concrete bulkheads or trench stops shall be provided in accordance with Clauses 13.4.11, 13.4.12 and Drawing SD 37C.
c
All pipelines laid on grades steeper than 50 percent are to be encased in concrete as detailed on Drawing SD 37C.
13.4.11 Trench Stops a
Where a pipeline is laid on bedding in accordance with Clause 13.8.2 at a grade ten percent or steeper, trench stops are to be located as follows and provided in accordance with Drawing SD 37C. i
At the socket side of the joint nearest to the position of a trench stop required in accordance with the formula hereinafter.
ii
The bags are to be placed to give close contact with the pipe and to fill the entire space between the excavated recess and the pipe. Bags will not be placed onto sand bedding.
The distance between trench stops will be determined by the following formula: D = 60 , whereby G D = Distance between stops in metres, G = Grade of pipe expressed in percentum. b
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Where pipelines are laid on bedding in accordance with Clause 13.8.3 the installation of trench stops shall not be required.
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13.4.12 Concrete Bulkheads Where a pipeline is installed at a grade of 20 percent or steeper concrete bulkheads of Grade 20 concrete 150mm minimum thickness will be constructed as follows and as indicated on Drawing SD 37C. Where concrete bedding to a pipeline is required as specified in Clause 13.4.10, the 150mm thick bulkhead will be cast integral with the concrete bedding. The bulkhead is to extend to 300mm below finished surface level. Refer Drawing SD37C. The distance between concrete bulkheads will be determined by the following formula: D = 600, whereby G D = Distance between bulkheads in metres, G = Grade of pipe expressed in percentum. 13.4.13 Thrust and Anchor Blocks Thrust and anchor blocks are to be constructed at valves, flexible jointed bends (both vertical and horizontal), tees, enlargers and reducers or any other point where unbalanced forces resulting from internal pressures will occur. The Developer is to provide permanent thrust blocks of minimum Grade 20 MPa concrete such that the thrust blocks bear against sound undisturbed material normal to the direction of thrust resulting from internal pressures over the calculated bearing area. Should the material be unsound against the proposed thrust block it shall be removed and replaced with approved compacted material. The Developer is to provide permanent anchor blocks complete with all necessary straps or reinforcement to a minimum Grade 20 concrete of a volume not less than that specified on the approved engineering plans or to the manufacturers specifications. All thrust and anchor blocks are to be designed by the Developer's Consultant and submitted to the Engineer for approval. 13.4.14 Protection of Pipelines a
Concrete Encasement (Non Reinforced) Where mains (excluding those in ductile iron) have less cover than that specified in Clause 13.4.6 and in situations where approved, the pipe shall be encased in concrete. Such concrete shall conform with the requirements of drawing SD 37C and shall have the following minimum dimensions:
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i
For trenches in other than rock: 150mm under, on both sides and on top of the pipe barrel.
ii
For trenches in rock: 100mm under the pipe barrel, 150mm on top of the pipe barrel and for the full width of trench excavated.
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Chapter 13 - Water Supply Reticulation - Design and Construction
b
Concrete Encasement (Reinforced) Reinforced concrete (or the alternative steel fibre reinforced concrete "Fibrecrete") encasement of a pipeline shall be provided where required as nominated in Clause 13.4.14 above. Concrete encasement shall be carried out in accordance with Drawing SD 37C.
c
Alternatives Notwithstanding Clauses 13.4.14(a) and 13.4.14(b) the Engineer may direct alternative pipe protection by specifying ductile iron.
13.4.15 Boring Under Existing Council Roads All Council roads shall be under bored except when otherwise approved. Where the provision of water mains requires the crossing of existing Council roads by under boring, the following requirements shall be met:.
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a
Construction will be by means of thrust boring or pipe jacking or another nonsurface disruptive construction.
b
The Developer is to supply all materials and plant for the work.
c
The encasing pipe is to be steel or reinforced concrete complying with the respective requirements of (i) and (ii) below. i
Steel encasing pipe is to be fabricated from steel having a specified minimum yield strength of 230 MPa and will have a minimum wall thickness of 8mm for inside diameter less than 450mm or 12mm for encasing pipes of larger inside diameter up to 800mm;
ii
Reinforced concrete encasing pipes are to be rebate jointed complying with AS 4058. The minimum class of pipe will be Class 4;
d
The inside diameter of the encasing pipe is to be at least 100mm greater than the largest outside diameter of the carrier pipe as measured at the joint or coupling to allow installation of the line to its design grade and line within the specified tolerances;
e
Subject to compliance with tolerance for line, grade and level, as outlined in Clause 13.9.3 the carrier pipe may be located anywhere within the encasing pipe. These requirements may be varied to allow the tolerance for line and level to be ±100mm;
f
After installation the Developer will fill the annular space between the main and encasing pipe completely with a grout mix complying with Clause 13.4.15(g). All precautions are to be taken to ensure that there is no movement of the carrier pipe from its line and grade during grouting. The water main will be filled with water prior to grouting;
g
Grout to be used for the sealing of the annular space is to be a mixture of cement, sand (1:12) and water, plus an admixture if specified.
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These materials are to be mixed to a consistency which satisfies the Engineer, so as to completely fill all voids within the annular space between the main and the encasing pipe. h 13.4.16
Testing of the line is to be in accordance with Clause 13.11. Pipe Crossings - RTA or SRA Property Notwithstanding the above, where the provision of water mains requires non surface disruptive crossings of RTA or SRA property the requirements of those authorities shall be sought by the Developer and complied with.
13.4.17
Encasing Under Trees Refer Drawing SD64 for details of service encasing under trees.
13.4.18
Main Marking a
Marker Posts and Plates The Developer shall provide location markers as specified below at each stop valve, air valve, scour, hydrant, change of direction and at no more than 200 metre intervals along straight sections. Reflectorised 250mm x 80mm aluminium notice plates are to be provided with red reflectorised lettering as detailed below with the size of the main and the distance from the fitting to an accuracy of 0.1m clearly stencilled on the plate with blue exterior enamel with numbers 25mm high. Marker Plate Identification
Water Main
Stop valve Air valve Scour with valve Change of direction Straight section
SV AV SCOUR WM BEND* WM
* Alternatively, provide blue topped post.
Notice plates may be attached to walls, fence posts or the like, where such a facility is no more than 6m from the indicated hydrant or valve. Where no existing permanent feature is available, a marker plate is to be attached to a marker post, conforming to Drawing SD40A. Posts are to be placed adjacent to property boundaries. Notice plates are to be cast into the posts. Where soft ground is encountered, the post is to be driven into the ground to a minimum depth of 600mm. b
Kerb Marking Main location marks shall be provided to accurately indicate the location of the water main crossing under the kerb and gutter using a 75mm high, 6mm thick impression in the face of the kerb. Refer Clause 10.16.
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13.4.19 Water Services a
General This section of the specification covers the construction of copper water services. The Contractor may supply alternative water services constructed in part from medium density polyethylene (MDPE) and install these to the requirements of AS3500.1 with materials approved by Sydney Water and the Hunter Water Corporation. Alternative water service systems are not to be used without the prior written approval of the Engineer.
b
Installation All water services are to be installed in accordance with the NSW Code of Practice - Water Supply. In urban residential developments for both long and short services (unless otherwise specified below) a 20mm single water service only is to be provided to 300mm inside each property. The service riser is to be vertical and terminate uniformly 250mm (+/- 25mm) above ground level with a capped No 13 Capillary Fitting which faces parallel to the front boundary. Every property is to have an individual service tapped from the main and serving only one property. The installation of dual services will not be permitted. Single water services over 30 metres in length, but less than 74 metres are to be 25mm up to, but excluding, the No 13 Capillary Fitting which shall be 25mm x 20mm in size. Service risers are to be supported by a hardwood stake painted white (minimum dimension 75mm x 50mm), driven firmly into the ground and fastened to the stake by a suitable pipe saddle. The stake is to have a finished height equal to the top of the water service. In rural areas it is the responsibility of the future lot owner to arrange for the provision of their water service from the main to meet their requirements in accordance with Council's standards. For commercial or industrial developments, services of appropriate size are to be provided. In many cases, sizes cannot be determined until individual developments are proposed. Separate mains on each side of the road may be required. Refer to Clause 13.4.4 for requirements of the Building Code of Australia for fire fighting services.
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c
Location Water services for all lots other than corner or battle axe lots are to extend at right angles from the main to the property serviced and are to be located in the centre of each front boundary of the property serviced. Variations to the previous requirement will be permitted where conflict between accesses and main cocks may occur. For corner lots, the service is to be located 3 metres away from the splay corner. For lots located opposite cross streets and lots with frontages less than 12 metres the service riser shall be located 400mm from the side boundary and short services are to be laid diagonally from the main to avoid the main cock being located under the concrete access crossing. Variations to the above may be permitted after approval from the Engineer in "Integrated Housing Estates" where the future dwelling location has been determined. Refer to Drawing SD 13 for water service location to battleaxe and multiple lots serviced via right of carriageway handles.
d
Licence Requirements A water service is deemed to be the pipes and fittings used or intended to be used in connection with the supply of water from the main to the property. Water services may only be installed by persons currently licenced under the New South Wales Plumber's Gasfitters and Drainers Act of 1979 as follows:
e
a
be the holder of a plumber's or water plumber's licence;
b
be the holder of a journeyman plumber's or journeyman water plumber's certificate of registration under the general control of a licensee referred to in (a);
c
be a person under the immediate supervision of a licensee referred to in (a).
Construction Depth Construction depths shall comply with Clause 13.4.6(b).
f
Materials - General A copper water service is to consist of the following components. All components shall be of a size equivalent to the size of the water service connected: i
Tapping Bands and Bolts Tapping bands are to be approved Gunmetal or Ductile Iron coated in accordance with Clause 13.5 incorporating an integral insulating bush which is assembled on the water main as shown on Drawing SD 35A. Gunmetal tapping bands will require an additional insulating bush between the main cock and the No. 64 fitting. The main is to have an 18mm minimum drilling for 20mm tapping bands and 22mm minimum drilling for 25mm tapping bands. Direct tapping of the water mains without the use of a tapping band is not permitted.
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ii
Main Cocks All main cocks are to be an approved right angled brass or gunmetal type with brass jumper valves.
iii
Copper Pipe Copper pipe is to be Type A and must comply to Australian Standard 1432 - 1983.
iv
Capilliary Fittings Capillary fittings are to be deep socketed and must comply to Australian Standard AS 3688 - 1990. All fittings must be copper coded "CU" or brass - gunmetal, coded "DR".
13.4.20 Alternative Materials Clause 13.5.6 details the requirements for any alternative water services offered by the Developer. 13.4.21 Water Service Testing Water services shall be tested in conjunction with the water main in accordance with Clause 13.11. 13.4.22 Service Marks Service marks shall be provided on the face of the kerb and gutter to accurately indicate the location of the water service crossing, using a 75mm high 6mm thick "W" impression in the green concrete. Refer Clause 10.16. 13.4.23 Main Cocks Under Concrete Footpaths and Driveways Wherever possible main cocks are not to be located under concrete driveways (refer Clause 13.4.19(c)). Approved cast iron path cock covers are to be placed over all main cocks under concrete footpaths and driveways where applicable. The path cock covers are to be removable lid type as manufactured by Farnell and Thomas or approved equivalent. Hinged path cock covers are not permitted. The covers are to be fixed plumb and square to the centreline of each main and 100mm NS UPVC minimum Class 9 pressure pipe is to be used as a protective sleeve between the cover and main cock as shown in Drawing SD 41C. 13.4.24 Landscape Irrigation Irrigation of landscape areas shall be designed and installed in accordance with the requirements of AS 3500.1 and approved by the Engineer. The installation of backflow prevention devices in this instance is mandatory.
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13.5
SUPPLY OF PIPES AND FITTINGS
13.5.1
General The Developer is to supply and deliver all pipes, fittings and other materials (with the exception of material supplied by Council under Clause 13.1.3) required to construct the work as detailed on the approved engineering plans, and in accordance with the following:
13.5.2
13.5.3
Quality Assurance a
In regard to the manufacture of products detailed in Clause 13.5 the Manufacturer will have implemented a Quality Control/Assurance System to ensure that all testing and manufacturing equipment, manufacturing processes, hardware, materials and workmanship meet the requirements of the specification or relevant Australian standard.
b
Except where otherwise specified, the Quality Control/Assurance System is to meet the minimum requirements of AS/NZS ISO 9002-1994 (Quality Systems for Production and Installation).
c
Prior to the use of any product on site, the Developer is to provide the Engineer with a Certificate of Compliance in accordance with Clause 13.5.3 from the manufacturer stating that all products supplied and which are listed in Clause 13.5 have been manufactured in accordance with AS/NZS ISO 90021994 (or the applicable Quality Standard) and comply with all specification requirements and relevant standards.
d
Where the Manufacturer of any of the products listed involves a number of Manufacturers, a certificate from the Head Manufacturer or Supplier will be accepted subject to the Head Manufacturer establishing Quality Procedures for the product supplied from other Manufacturers and verifying such quality in accordance with the required standard.
Certificate of Compliance As a prerequisite to acceptance of any pipe, fitting, or valve delivered to site, the Developer is to obtain, and provide to the Engineer, upon delivery, a certificate in accordance with Clause 13.5.2(c). The certificate is to include but not be limited to the following: a b c d
the Developers name or reference number; the name of the Manufacturer; the plant where the items were fabricated; the signature of the Manufacturer's Quality Assurance Officer at the plant and the signature of the Developer's representative on site, confirming compliance of items with the contract conditions.
Any items which are delivered without a certificate are liable to rejection.
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The acceptance by the Engineer of items or goods supplied by the Developer based upon the Certificate of Compliance shall not constitute approval of any items or other matters nor shall it prejudice any right or claims by the Engineer to later reject items or materials found not to comply with this requirement of the specification. 13.5.4
Pipe Material Unless otherwise approved all water mains are to be constructed using minimum Class 12 rubber ring jointed UPVC pipe, complying with the requirements of AS/NZS 1477 - 1996 - PVC Pipes and Fittings for Pressure Applications - Series 2 pipes with sizes compatible with cast iron pipes and fittings and this specification. For pipe sizes where UPVC is not available, alternate pipe material is to be used in accordance with Clause 13.5.6.
13.5.5
Pipe Fittings: General Pipe fittings are to be manufactured from ductile iron or cast iron in accordance with AS 2280 or AS 2544 respectively and further as specified in Clause 13.5.7. All fittings up to and including 200mm nominal size are to be socket ended and either coated internally and externally with a thermoplastic polyamide (Rilsan Nylon 11) or a thermosetting epoxy powder (NAP-GARD 7-2501) applied using the fluidised bed process in accordance with Australian standards interim specification No 101 Revision 2, dated September 1991 (attached as Appendix "C"). All spring hydrants and stop valves (up to and including 200mm nominal size) are to be coated internally and externally with a thermoplastic polyamide (Rilsan nylon 11) or thermosetting epoxy powder (NAP-GARD 7-2501) in accordance with this clause and be supplied complete with stainless steel bolts, nuts and washers. Stop valves over 200mm nominal size may be bitumen coated cement lined and wrapped with an approved multi-purpose petrolatum based long life corrosion protection system such as Denso or Corrocote. Full details of alternative coating systems are to be submitted prior to their use for the Engineer's approval. Where fittings cannot be supplied that meet the nylon coating requirement because of size or some other limitation, they may be bitumen coated cement lined and wrapped in polyethylene sleeving in accordance with the manufacturer’s specifications typically Century Plus. Refer Clause 13.9.7.
13.5.6
Alternate Pipe Material and Fittings Where the approved drawings indicate pipeline or fittings constructed of other materials, these items are to have performance ratings equivalent to or better than that specified in Clauses 13.5.4 and 13.5.5 and are to comply with all other aspects of this specification. Where other pipe materials and fittings are offered full technical details are to be submitted to the Engineer for consideration and shall include:a b
April 1999
Technical specification. Statement of Warranty from the manufacturer disclosing suitability of pipe material and/or fittings for intended use.
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c d e
Details of previous usage in similar situations. Copies of approvals/authorisation of use and any specific requirements of other water supply authorities. The current and projected availability of materials and fittings required for maintenance or connection works and their cost comparisons to currently used materials.
Alternative pipeline and fittings materials are not be used without the prior written approval of the Engineer. 13.5.7
Pipe Jointing Systems Notwithstanding the requirements of this clause all flexible joints for pipes and fittings are to be manufactured in accordance with the requirement of this specification to produce a watertight joint with rubber rings or other means having a similar degree of flexibility. Rubber rings are to conform to the requirements of AS 1646 - 1987. All fittings for UPVC pipelines are to be socket ended unless otherwise specified and approved. All rubber seals and sockets are to be fully compatible with Class 12 UPVC pipe. The socket profile of the fittings is to be of a design incorporating dimensions which provide sufficient depth to allow an effective sealing length along the pipe spigot and is to be sufficient to allow for the following movement without affecting its water tightness:a
longitudinal movement due to ground strains, mine subsidence and temperature change;
b
angular deviation resulting from ground strains and construction.
c
provide a maximum deflection of 3o.
For development within proclaimed mine subsidence areas, (refer Clause 13.2) jointing systems are to be capable of accommodating movement in accordance with Clause 13.5.9. For development not within proclaimed mine subsidence areas standard proprietary jointing systems may be used. In accordance with Clause 13.5.3 the manufacturer is to state on the Certificate of Compliance that the pipe jointing system supplied will meet all mine subsidence requirements detailed in Clause 13.5.9. Where other types of flexible joints, pipelines etc are offered the requirements of Clause 13.5.6 shall apply. Any pipes, fittings and accessories used in the work incorporating a non-approved jointing system shall be rejected. 13.5.8
Witness Marks A full circle witness mark is to be provided on each spigot of all pipes supplied by the pipe manufacturer. The position of the witness mark is to take into account allowances required for mine subsidence in accordance with Clause 13.5.9. The Developer is to lay the pipes such that the centreline of the witness mark or groove,
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or at least one point thereof, is in the plane of the face of the socket and such that no portion of the centreline is inside the socket. The permissible deflection as recommended by the Manufacturer is not to be exceeded, provided that the requirements of the specification shall take precedence. Any pipes cut to length are to have their witness mark reinstated at the position recommended by the Manufacturer prior to jointing. 13.5.9
Mine Subsidence Joints Where pipelines are subject to ground movements due to mine subsidence, flexible joints must comply with the following. When a joint is assembled so that adjacent pipes are co-axial and the end of the spigot is located at the bottom of the socket, or at the centre of the coupling, or collar the spigot should be capable of being withdrawn without impairing the water tightness of the joint a minimum distance M as follows: a
For spigot and socket pipes of steel, ductile iron, cast iron, vitrified clay and concrete: M min
b
=
3SL + θD
For spigot and socket pipes of UPVC: M min
=
3SL + θD + [1.5 α t T] L
-5 o o o (Note: For α t = 8.1 x 10 / C and T = 22 C (ie +/- 11 C), the value of 1.5 α t T is 0.0027) c
For pipes with couplings: M min
=
1.5 SL + 0.5 θD
Where: S = design ground strain given as +/- mm/m * L = length of pipe in mm. θ = permitted angular deflection at joint in radians. D = inside diameter of socket or coupling in mm. *
Actual design ground strain should be obtained from the Mines Subsidence Board for the work area. (Refer Clause 13.2)
When determining the effective depth of a socket, or the length of a coupling or collar, required to accommodate the relevant movement M, any chamfer at the spigot end is to be taken into consideration. A full circle witness mark or groove is to be provided on each spigot. The centre line of such mark or groove is to be at a distance W from the spigot end as follows: a
For spigot and socket pipes of steel, ductile iron, cast iron, vitrified clay and concrete: W
b
April 1999
= depth of socket - SL
For spigot and socket pipes of UPVC:
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W
= depth of socket - (SL + [0.5 α t T] L)
-5 o o o (Note: For α t = 8.1 X 10 / C and T = 22 C (ie +/- 11 C) the value 0.5 t T is 0.0009) c
For pipes with couplings: W
= 0.5 (length of coupling - SL)
13.5.10 Fasteners All bolts and washers for flanged coated fittings that are to be buried in the ground are to be stainless steel grade 316 to AS 1444. All nuts are to be stainless steel Grade 304. All other bolts, washers and nuts that are not buried in the ground may be hot dipped galvanised in accordance with AS 1650. Before and during assembly all stainless steel components are to be thoroughly coated with a copper impregnated grease such as Ampol "Koper-Cote" or approved equivalent. All exposed boltheads and nuts are to be hexagonal and the length of all bolts is to be such that when fitted with a nut and tightened down the threaded portion will fill the nut and not protrude from the face thereof by more than half a diameter. 13.5.11 Fittings a
Hydrants All hydrants are to be of the spring hydrant type complying with AS 3952 1991 and shall be coated with a fluidised bed system in accordance with Clause 13.5.5.
b
Stop Valves All stop valves are to be a minimum Class 14, socketed cast iron, anti-clockwise closing and are to conform to AS 2638 as amended. Flanged valves with flange to socket valve connectors will be acceptable. All stop valves up to and including 200 mm nominal size are to be resilient seated in accordance with AS 2638 and are to be coated internally and externally with a fluidised bed coating system as specified in Clause 13.5.5. All stop valves above 200 mm nominal size are to be resilient seated or metal seated in accordance with AS 2638, and are to be coated in accordance with Clause 13.5.5. Stop valves are to be provided as detailed in Clause 13.9.6 and are to be suitable for the type and class of pipe used.
c
Gibault Joints All gibault joints used are to be of the long sleeve type and are to be suitable for the type and class of pipes being used.
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All gibault joints are to be coated internally and externally with a fluidised bed coating system as specified in Clause 13.5.5. Gibault joints are only to be used as directed by the Engineer. A 6mm spacing is to be maintained between the two lengths of pipe joined, and, if directed a spacer shall is to be used to reduce this gap. The gibault joint is to be assembled to the Manufacturer's specification. Stainless steel fasteners conforming to Clause 13.5.10, are to be used on all gibault joints buried in the ground. 13.5.12 Handling and Storage a
The method of loading and storage of pipes and fittings is to be in accordance with the Manufacturer's recommendations and further as follows:
b
When handling UPVC pipes and fittings the Developer is to comply with the following particular requirements: i
Pipes and fittings are not to be dropped and impact with other objects is to be avoided, especially in cold weather.
ii
Any pipes which are to be stored for more than five weeks are to be protected from sunlight, if necessary by covering with building paper or other approved material.
iii
When pipes and fittings are to be jointed, the spigots are to be pushed into the sockets by hand or the joint may be effected using approved implements such as pullers having jaws lined with rubber or similar material in order to avoid scoring the pipe. The use of lever bars will only be permitted if adequate and suitable protection from damage is applied to the end of the pipe being levered.
13.6
EARTHWORKS
13.6.1
General All excavation will be to the lines and grades (where applicable) shown on the approved engineering drawings within the specified tolerances. Where earthworks requirements outlined in this Clause conflict with the pipe manufacturers recommendation the requirements of the manufacturer shall apply.
13.6.2
Trench Width For All UPVC Pressure Pipelines a
Minimum Width The minimum clear width of trench (inside internal faces of timbering or travelling box, if used) to a height of 150mm above the top of the pipe is to be the nominal size of the pipe plus 250mm
b
Maximum Width The maximum width of trench from the trench base to a height of 150mm above the top of the pipe is to be the nominal size of the pipe plus 400mm. However, in timbered or travelling box excavated trenches, the width of
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Chapter 13 - Water Supply Reticulation - Design and Construction
trench when measured to the outside of the support used may be increased to a maximum of 580mm plus the nominal size of the pipe. c
Extra Width Excavation Where the width of trench below a level of 150mm above the top of the pipe is greater than the maximum specified above, from any cause whatsoever before or after laying of the pipe, the Developer is to remove all disturbed material from the trench. The Engineer may then direct one or more of the following: i
Bedding and laying, as specified further in Clauses 13.8 and 13.9 of this specification for the same pipe;
ii
Installation of a heavier class of pipe;
iii
Filling the space between the pipe and the undisturbed ground on both sides of the pipe and to a height of 300mm above the top of the pipe with sand or granular material of the type approved for pipe bedding as specified in Clause 13.8. Such sand or granular material is to be compacted in layers not greater than 150mm thick in accordance with Clause 13.10.1.
iv
Bedding of the pipe on a concrete cradle extending a minimum of 100mm on each side of the outside diameter of the pipe, a minimum of 100mm under the barrel and to a level above the bottom of the pipe of one quarter of the external diameter of the pipe.
Backfilling and compaction for the remainder of the trench is to be in accordance with Clause 13.10.1. 13.6.3
Excavation Depth Excavation is to be carried out to a depth of not less than 75mm below the underside of the pipe barrel and socket or coupling in the case of earth foundations and 100mm below the underside of the pipe barrel and socket or coupling in the case of rock foundations.
13.6.4
Extra Depth Excavation In the case of poor ground conditions extra depth is to be excavated in order to obtain a firm trench bottom. The additional excavation is to be re-filled to the level required for bedding of the pipe with an approved fine non-cohesive material such as sand or fine crushed rock, placed in layers 150mm thick and compacted by approved means. Notwithstanding the above, where excavation in a trench has been carried out to a level deeper than the level required and can not be soundly justified, the Developer is to remove all disturbed material from the bottom of the trench and refill the overexcavated portion to the required level with approved compacted material.
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13.6.5
Dewatering Trenches will be kept free of water after excavation and during construction of the pipeline by means of internal or external dewatering or other approved ground stabilising techniques. Dewatering shall be carried out in accordance with Clause A.10.1. Any auxiliary excavation carried out in or adjacent to the trench excavation for that purpose will be backfilled by the Developer in accordance with this specification as applicable. Where sub-drains have been used, this may include backfilling with grout consisting of not less than one part of cement to ten parts of sand when batched by volume.
13.6.6
Support of Excavations Where required, the Developer will adequately support all trenches and excavations as the works proceed. All trench support systems will conform to the requirements of the current Construction Safety Act and Occupational Health and Safety Act. When withdrawing any supports, the Developer is to ensure against slips or falls by means of intermediate shoring, planking or props. Backfilling and compaction is to be performed simultaneously with the withdrawal of supports. Timber shoring may be required to be left in place where its removal may endanger structures or other property in the vicinity of the excavation.
13.7
EROSION AND SEDIMENT CONTROL In the event of any trenching being left open for periods exceeding seven days the Developer shall provide erosion control measures to ensure minimal soil disturbance and material loss off the site. These measures are to be provided as outlined in Appendix A - Control of Erosion and Sedimentation. Additional control measures may be necessary as detailed below. Such measures shall be as directed. a
provision of trench stops every 30 metres within the trench with provision for overtopping to be directed to the kerb.
b
Placement and maintenance of blue metal bags along kerb and gutter at maximum 30 metre spacings.
c
Placement and maintenance of blue metal bags around downstream drainage pits.
d
Construction of diversion banks to divert the uphill catchment water from entering the trench.
13.8
PIPE BEDDING
13.8.1
General When excavation of a trench has been completed, the Developer is to provide bedding of the pipe in accordance with the following requirements: Where the manufacturers bedding requirements exceed those outlined below, the requirements of the manufacturer shall apply.
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13.8.2
Sand Bedding For all pipe materials the material to be used for pipe bedding (underlay a minimum of 75mm below the pipe barrel and socket for earth foundations and 100mm for rock foundations), side support and overlay to a minimum depth of 150mm above the top of the pipe (as specified in Figure 5.1 in AS 2032) is to be sand or other approved non-cohesive granular material, either crushed natural or blended, and its grading shall fall within the following limits: Sieve Size Aperture Width (AS 1152) 9.5mm 6.7mm 425um 150um
Equivalent B.S. Sieve Size (BS 410) 3/8 inch 1/4 inch No 36 No 100
Percentage Passing 100 90-100 40-90 0-10
The material is to be compacted under, around and to 150mm above the top of the pipe and is to extend for the full width of the trench. Refer Clause 13.10.1. Sand bedding shall be used in all cases, except where the provisions of Clause 13.8.3 prevail. 13.8.3
Granular Bedding Non-cohesive granular bedding and surround shall be used in saturated ground. The material used for pipe bedding, side support and overlay (to a depth of 150mm over the top of the pipe) shall be graded aggregate, either crushed rock or gravel with no sharp edges, with grading to fall within the following limits: Sieve Size Aperture Width (AS 1152) 19.0mm 16.0mm 13.2mm 8.0mm 4.75mm
Equivalent B.S. Sieve Size (BS 410) 3/4 inch 5/8 inch 1/2 inch 5/16 inch No. 4
Percentage Passing 100 50 - 80 30 - 65 15 - 50 0 - 10
Where such graded aggregate is being used, the installation of trench stops will not be required. 13.9
LAY AND JOINTING
13.9.1
Installation Details - General Pipes shall be laid and jointed in accordance with the Manufacturer's instructions and the provisions of this specification. Where the manufacturers pipe laying requirements exceed those outlined in this specification the requirements of the manufacturer shall apply. Before being, laid all pipes, fittings, valves, etc, are to be cleaned. The Developer is to suspend each or any pipe length in a sling to enable inspection by the Engineer if required. If directed, the Developer is to oil valves and repack valve glands.
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The Developer is to provide and use approved drag scrapers or "detectors" to ensure that the interior of the pipeline is clean and free from obstructions. Approved plugs are to be used to prevent foreign matter entering sections of the pipeline which are left uncompleted overnight or during the day. The Developer is to take all necessary precautions to prevent flotation of pipes during laying, backfilling and initial testing. Any temporary supports are to be removed prior to completion of backfilling. UPVC pipes and fittings are not to be installed above ground, unless adequate support and special protection against direct sunlight is provided to the manufacturers specifications. 13.9.2
Pipe Grading and Alignment All pipelines are to be laid on the grade and alignment as shown on the approved engineering plans within the specified tolerances; otherwise the requirements of Clause 2.33 shall apply. Pipelines with approved gradual changes in alignment or grade are to be laid with the joint being deflected after it has been made. The allowable maximum deflections for each joint specified below is to be complied with provided that no joint is deflected to such an extent as to impair its effectiveness. Manufactured curved pipes are permitted. Refer Clause 13.4.3.C. Deflections of pipe joints within mine subsidence areas are to be reduced or the sockets adjusted so the sum of the deflection and the effective socket depth based on the design ground strain does not exceed the tolerance detailed below.
13.9.3
Tolerances Water pressure pipelines shall be installed to meet the following criteria: a
Horizontal deviation from design alignment: ± 50mm
b
Vertical deviation from design invert level (where applicable). Fittings for 200mm dia mains and larger require additional cover. Where design inverts are nominated it is generally provided to ensure conflict with other services does not occur and the nominated tolerance is to be ±20mm.
c
Angular deviation at any flexible joint: Pipes laid in a non mine subsidence area: The Manufacturers recommended maximum deflection to be used however, the requirements of Clause 13.9.2 shall apply. Pipes laid in a mine subsidence area: Up to 50% of the Manufacturers recommended maximum deflection to be used however, the requirements of Clause 13.9.2 shall apply.
d
April 1999
All pipes in a length between design low and high points are to have a continuously rising grade towards the high point. Isolated high points entrapping air shall require the installation of a hydrant. Refer Clause 13.4.7.
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e
Locate hydrants clear of roadways and driveways unless otherwise approved. Install valves, scours, tees, bends and other fittings and structures within 300mm of design location along pipeline. Notwithstanding the above, cover requirements are to be in accordance with Clause 13.4.6.
13.9.4
Reinstating Witness Marks For UPVC pipes, only the lubricant specified by the Manufacturer is to be applied in making the joint. When the joint is made, the witness mark is at no point to be more than 1mm from the end of the socket. Where pipes are to be cut in the field, a witness mark is to be made on the pipe at the length from the end of the pipe specified by the Manufacturer as detailed in Clause 13.5.8. Scoring of UPVC pipes is not permitted. Pencil or similar is to be used to make the witness mark. Where spigots and sockets are not made by the same Manufacturer, reference are to be made to the socket Manufacturer for the correct marking depth and suitability of the spigot dimensions and the socket manufacturers gasket requirement.
13.9.5
Cutting of Pipes Pipes may be cut as required to the manufacturers specification to suit closing lengths, to remove damaged parts or to remove sockets if necessary when jointing a socketed fitting. For field cuts, only an approved mechanical pipe cutter is to be used, except that UPVC pipes may be cut using a power saw or a fine toothed hand saw and mitre box.
13.9.6
Pressure Pipeline Fittings a
Stop valves and hydrants and other fittings are to be inserted where shown on the approved engineering plans or as directed. Stop valves and hydrants are to be fixed plumb and square to the centre line and at a depth to provide clearance of between 150mm (minimum) to 300mm (maximum) from the top of the valve spindle or hydrant to the top of the surface box lid as shown on Drawing No SD 41C. All valve and hydrant boxes are to be "proud" of the general footpath finished level by 25mm. A minimum 300mm width strip of couch turf is to surround the finished box construction unless otherwise approved. The Developer's attention is directed to the minimum pipeline cover requirements detailed in Clause 13.4.6.
b
All stop valves and hydrants will be provided with a cast-iron cover box and a concrete surface box all conforming to the requirements of this clause and Drawing SD 41C. Surface blocks are to be constructed of reinforced Grade 20 concrete with 20mm coarse aggregate and is to be a maximum of 570mm in diameter or 570mm square as detailed on Drawing SD 41C.
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Hydrant box and concrete surrounds are to be supplied as a two-part non-bonded assembly and must be compatible with each other to ensure flush finish. Hydrant boxes cast into concrete surrounds will not be acceptable. The surface finish of the concrete blocks is to be smooth and dense. Blocks are to be properly cured prior to placement. c
Protective boxes for stop valves and hydrants are to be constructed around the fitting stems and are to consist of interlocking concrete blocks conforming to Drawing SD 41C. The walls are to provide firm and even support for the concrete surface block. Stop valves shall be provided with a minimum diameter 150mm UPVC pipe installed vertically over the valve spindle. Notwithstanding this the pipe shall be of a sufficient diameter to enable the insertion and operation of a valve key of a size commensurate with the size and class of the valve installed. The pipe sleeve shall be installed in accordance with Drawing SD 41C. The pipe shall be installed vertically in such a manner as to prevent the ingress and filling of the pipe with backfill material.
13.9.7
Polyethylene Wrapping Of Pipelines and Fittings Ductile Iron a
All ductile iron pipes and fittings not nylon-coated shall be wrapped in polyethylene sleeving in accordance with the manufacturers specifications typically "Century Plus". Any damage done to the polyethylene tubing before, during or after backfilling of the trench or to existing service wrappings will be made good by the Developer at no cost to Council.
b
When polyethylene sleeving has been provided in accordance with the specifications, pipe bedding, side support and overlay for the pipeline shall be sand or other approved non-cohesive granular material conforming to Clause 13.8.2. Aggregate, crushed rock or gravel bedding with sharp edges shall not be used for the bedding or backfill around polyethylene sleeved pipelines.
13.9.8
Main Damage Particular care is to be taken to avoid scratching or otherwise damaging the UPVC pipes and fittings whenever the backfill is compacted by tamping. Tampers and method(s) of compaction are subject to approval.
13.10
BACKFILLING AND COMPACTION
13.10.1 General a
April 1999
When laying and jointing of a pipeline has been completed and before backfilling has commenced, the Developer is to request the Engineer for an inspection and approval to proceed with the works. At this stage the Developer is encouraged to satisfy himself that the pipe line is correctly laid in relation to line and level.
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b
Backfill down to within 150mm of the pipe surround material is to be free of large stones, rocks or hard nodules and if suitable may be taken from the excavated material. Such material is to be compacted as specified below. Where insufficient approved excavated material is available the Developer shall import approved select backfill material. Surplus material not suitable for backfilling shall be removed and disposed of in an approved manner.
c
Trenches subject to vehicular traffic shall have all backfill material fully compacted in layers not more than 150mm thick to 100% of standard maximum dry density ratio in accordance with AS 1289 for cohesive materials and 65% density index determined in accordance with AS 1289 for non-cohesive material to the subgrade level of the road or the finished surface level as directed. Backfill from the subgrade level to the road surface level is to be an approved road base material to a minimum depth of 300mm or the approved design pavement thickness. Compaction of the backfill material will be by mechanical means unless the backfill material is suitable for compaction by flooding with compactive effort. Flooding of cohesive materials will not be permitted. Prior to backfilling and compaction of trenches subject to vehicular traffic, trenchstops conforming with Drawing SD 37C are to be provided across the full width of the excavated trench directly behind the kerb, or where no kerb exists, behind the road shoulder to contain the compacted material.
d
Within lots in integrated housing developments or in areas other than under roadways, the backfill is to be compacted as specified above to 95% of the standard maximum dry density ratio in accordance with AS1289.
e
Where compaction is ordered and the trench has been externally dewatered, the dewatering equipment is to be kept operating until the compaction of the trench has been completed. Water discharge from external dewatering equipment may be used for compaction by flooding with compactive effort where such backfill is of a non-cohesive free draining nature.
f
Backfilling and compaction is to be carried out without damaging the pipe or its external coating or producing any movement of the pipe. Any subsidence or scouring of the trench backfill during the specified maintenance period will be rectified by the Developer at no cost to Council.
g
Testing will generally be in accordance with the requirements of Clause 8.5.5 for road crossings (trafficable areas) and where considered necessary elsewhere.
13.10.2 Restoration All restoration works shall be carried out in accordance with the requirements of Clause 6.19 and 10.6.4 in the case of concrete footpath crossing restoration works.
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13.10.3 Maintenance All restored surfaces are to be maintained in the condition to which they are restored until the expiry of the Maintenance Period (refer to Clause 2.34) applicable to those surfaces. The additional requirements of Clause 2.35 shall also apply. 13.11
TESTING OF WATER MAINS AND SERVICES
13.11.1 General All pressure pipelines and associated services are to be pressure tested in accordance with this sub-clause prior to the acceptance of the works by the Engineer and to the connection onto Council's mains, in order to detect excessive leakage and defects in the pipeline including joints, thrust and anchor blocks. 13.11.2 Method of Carrying Out Test a
Pipelines Pipelines are to be tested in approved sections as soon as practicable after each section has been laid, jointed and backfilled and water services connected, provided that: i
if so specified, or if the Developer so desires, or if required by the pipe manufacturer, some or all of the pipe joints may be left uncovered until the whole of the section has been successfully pressure tested; and
ii
the pressure testing is not to commence earlier than seven days after the last concrete thrust or anchor block in the section has been cast.
For the purpose of this sub-clause, a section is defined as a length of pipeline which can be effectively isolated for testing, ie by means of main stop valves or other approved means. Unless otherwise approved, pressure testing is not to be carried out during wet weather. During the pressure testing of a pipeline each stop valve is to sustain at least once, the full test pressure on one side of the valve in closed position with no pressure on the other side for at least 15 minutes. Before testing a pipeline section it is to be adequately cleaned and filled slowly with clean water, taking care that all air is expelled. Purging of air from pipelines is to be promoted by opening air valves or hydrants as applicable. In order to achieve conditions as stable as possible for testing the section is to be pressurised to 75% of the specified test pressure and held for a period of not less than 12 hours prior to the commencement of the pressure testing. The hydrostatic test pressure which is to be applied to each section of the pipeline is to be 1000 kPa, as measured at the lowest point in the main or such pressure as advised by the Engineer, whichever is greater.
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Chapter 13 - Water Supply Reticulation - Design and Construction
Raise and maintain the pressure to the specified test pressure as long as required for examination of the whole of the section, and in any case not less than 4 hours. For the purpose of determining the actual leakage losses, the quantity of water added in order to maintain the pressure during the period of testing is to be carefully measured and recorded. b
Water Services The Developer is to arrange hydro-static testing of water services in conjunction with charging and testing of the reticulation mains (refer Clause 13.11.1). Air is to be purged from each service and the No 13 Capillary Fittings are to be capped with a BSP galvanised cap, the main cocks are to be left open. Water usage from any water service is not authorised until Council has received a water service application and a meter installed. Refer to Clause 13.11.5.
13.11.3 Allowable Leakage Tolerances The pressure testing of a section will be considered to be satisfactory if: a
there is no failure of any thrust block, anchor block, pipe, fitting, valve, joint or any other pipeline component including water services; and
b
there is no visible leakage; and
c
the average measured leakage rate during the last 4 hours of the pressure testing does not exceed the following maximum loss rate: Allowable lose rate (L/hr) = where:
1.4 x 10-7 x D x L x H D L H
= = =
pipe diameter (mm) pipeline length (m) average test head (m) on section under test
13.11.4 Repair of Leaks Any failure, defect, visible leakage and/or excessive leakage rate, which is detected during the pressure testing of the pipeline is to be made good by the Developer at his expense and the pipeline retested. The Developer shall remove and replace all such defects or failures from the main under test by the use of gibault joints conforming to the requirements of this specification or other approved proprietary repair system that provides equivalent joint movement and deflection as the original installed pipeline joint system. In making good the pipeline no more than two (2) gibault joints or alternative repair fittings shall be permitted in any 250 metre section of pipeline under test.
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Chapter 13 - Water Supply Reticulation - Design and Construction
13.11.5 Council Acceptance Following successful completion of all testing and repair work on the main and services and the acceptance of the work, the works may be connected to Council's main (refer Clause 13.1.3). Following this connection the work is to remain charged at all times. The Developer or the Contractor is not to operate, adjust, interfere or take water from the main without the prior approval of the Engineer. Non-compliance of this requirement will be deemed to be an offence under the Water Authority Act 1987 as amended and accordingly penalties as prescribed under the Act may be applied.
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