AS/NZS 1546.1:1998

Australian/New Zealand Standard®________________________________________________________

On-site domestic wastewatertreatment units

Part 1: Septic tanks________________________________________________________

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This Joint Australian/New Zealand Standard was prepared by Joint Technical Committee WS/13 On-siteDomestic Wastewater Management. It was approved on behalf of the Council of Standards Australia on13 February 1998 and on behalf of the Council of Standards New Zealand on 9 January 1998. It waspublished on 5 April 1998.

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The following interests are represented on the committee responsible for this draft Australian/ New ZealandStandard:

Association of Certification Bodies (Australia)Australian Society of Soil Science Inc.Australian Water and Wastewater AssociationBureau of Steel Manufacturers of AustraliaComposites Institute of Australia Inc.Department of Health New South WalesDepartment of Health TasmaniaDepartment of Human Services VictoriaDepartment of Natural Resources QueenslandEnvironment Protection Authority of VictoriaEnvironment Management Industry Association of AustraliaHealth Department of Western AustraliaInstitution of Engineers AustraliaMaster Plumbers AustraliaNational Precast Concrete Association of AustraliaPlastics and Chemical Industries Association IncorporatedPublic Works Department New South WalesQueensland Confederation of IndustryQueensland Department of Housing Local Government and PlanningSouth Australian Health CommissionVictorian Precast Septic Tank Manufacturers Association Inc.

Association of Rotational Moulders (Australasia)

Composite Association of New ZealandInstitute of New Zealand Plumbing and Drainage InspectorsInstitution of Professional Engineers New ZealandLocal Government New ZealandMinistry of Health New ZealandNew Zealand Institute of Environmental Health IncorporatedNew Zealand Manufacturers FederationNew Zealand Society of Master Plumbers & GasfittersNew Zealand Water and Wastes AssociationThe University of Auckland Department of Civil and Resource Engineering

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Review of Standards. To keep abreast of progress in industry, Joint Australian/New Zealand Standards aresubject to periodic review and are kept up to date by the issue of amendments or new editions as necessary.It is important therefore that Standards users ensure that they are in possession of the latest edition, and anyamendments thereto.Full details of all Joint Standards and related publications will be found in the Standards Australia andStandards New Zealand Catalogue of Publications; this information is supplemented by the magazines 'TheAustralian Standard' and 'Standards New Zealand', which subscribing members receive, and which givedetails of new publications, new editions and amendments, and of withdrawn Standards.Suggestions for improvements to Joint Standards, addressed to the head office of either Standards Australiaor Standards New Zealand, are welcomed. Notification of any inaccuracy or ambiguity found in a JointAustralian/New Zealand Standard should be made without delay in order that the matter may beinvestigated and appropriate action taken.

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This Standard was issued in draft form for comment as DR 96033.

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AS/NZS 1546.1:1998

Australian/New Zealand Standard®________________________________________________________

On-site domestic wastewatertreatment units

Part 1: Septic tanks________________________________________________________

Originated in Australia as AS A178-1968.

Final Australian edition AS 1546-1990.

Originated in New Zealand in part as NZCP 44:1961.

Final New Zealand edition NZS 4610:1982.

AS 1546-1990 and NZS 4610:1982 jointly revised, amalgamated and

redesignated AS/NZS 1546.1:1998.

PUBLISHED JOINTLY BY:

STANDARDS AUSTRALIA1 The Crescent,Homebush NSW 2140 Australia

STANDARDS NEW ZEALAND155 The Terrace,Wellington 6001 New Zealand

ISBN 0 7337 1882 5

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PREFACE

This Standard is one of a series being prepared by the Joint Standards Australia/Standards New ZealandCommittee WS/13 on On-site Domestic Wastewater Management. It will supersede AS 1546-1990, Smallseptic tanks, and NZS 4610:1982 (in part), Household septic tank systems. Other Standards coveringaerated wastewater treatment systems and waterless composting toilets are in the course of preparation.

There is a twofold objective in this Standard. The first is to provide a set of performance statements whichdefine the requirements of a septic tank and which provide a base against which any septic tank,conventional or innovative may be assessed. The second is to provide manufacturers of conventional septictanks and associated fittings systems made of various materials with basic manufacturing and testspecifications. These will enable certification bodies to check that a product conforms to the Standard.

The illustrations used in this Standard are diagrammatic only and are chosen to illustrate principles ofdesign or operation.

The terms ‘normative’ and ‘informative’ have been used in this Standard to define the application of theappendix to which they apply. A ‘normative’ appendix is an integral part of a Standard, whereas an‘informative’ appendix is only for information and guidance.

Clauses prefixed by “C” and printed in italic type are comments, explanations, summaries of technicalbackground, recommended practice or suggest approaches which satisfy the intent of the Standard.Corresponding mandatory clauses are not always present.

Copyright – STANDARDS AUSTRALIA/STANDARDS NEW ZEALAND

Users of Standards are reminded that copyright subsists in all Standards Australia and Standards New Zealand publications and software. Exceptwhere the Copyright Act allows and except where provided for below no publications or software produced by Standards Australia or StandardsNew Zealand may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing fromStandards Australia or Standards New Zealand. Permission may be conditional on an appropriate royalty payment. Australian requests for permissionand information on commercial software royalties should be directed to the head office of Standards Australia. New Zealand requests should bedirected to Standards New Zealand.

Up to 10 percent of the technical content pages of a Standard may be copied for use exclusively in-house by purchasers of the Standard withoutpayment of a royalty or advice to Standards Australia or Standards New Zealand.

Inclusion of copyright material in computer software programs is also permitted without royalty payment provided such programs are usedexclusively in-house by the creators of the programs.

Care should be taken to ensure that material used is from the current edition of the Standard and that it is updated whenever the Standard is amendedor revised. The number and date of the Standard should therefore be clearly identified.

The use of material in print form or in computer software programs to be used commercially, with or without payment, or in commercial contracts issubject to the payment of a royalty. This policy may be varied by Standards Australia or Standards New Zealand at any time.

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CONTENTSPage

Preface ........................................................................................................................................... 2Referenced documents .............................................................................................................................. 7

SECTION

1 GENERAL1.1 Objective............................................................................................................................. 61.2 Scope .................................................................................................................................. 61.3 Application ......................................................................................................................... 61.4 Legislation .......................................................................................................................... 71.5 Referenced documents ........................................................................................................ 71.6 Definitions ........................................................................................................................ 7

PERFORMANCE

2 PERFORMANCE REQUIREMENTS AND PERFORMANCE CRITERIA2.1 Scope ................................................................................................................................ 102.2 Function and context of use ............................................................................................. 102.3 Performance requirements ............................................................................................... 102.4 Performance criteria ........................................................................................................ 11

MEANS OF COMPLIANCE

3 GENERAL REQUIREMENTS OF CONVENTIONAL SEPTIC TANKS3.1 Scope ................................................................................................................................ 163.2 Septic tank capacities ........................................................................................................ 163.3 Materials durability........................................................................................................... 163.4 Design .............................................................................................................................. 163.5 Inlet fittings and outlet fittings ..........................................................................................163.6 Position of inlet and outlet fittings in tank......................................................................... 183.7 Gas baffles ........................................................................................................................ 183.8 Partitions .......................................................................................................................... 183.9 Vents ................................................................................................................................ 193.10 Access openings and covers............................................................................................... 193.11 Extensions ........................................................................................................................ 193.12 Marking............................................................................................................................ 193.13 Installation........................................................................................................................ 19

4 MARKING OF SEPTIC TANKS4.1 Scope ................................................................................................................................ 244.2 General ............................................................................................................................ 244.3 Requirements .................................................................................................................... 24

5 TESTING REQUIREMENTS OF SEPTIC TANKS5.1 Scope ................................................................................................................................ 255.2 Type testing ...................................................................................................................... 255.3 Routine quality testing ...................................................................................................... 255.4 Quality certification .......................................................................................................... 25

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Page6 PRECAST CONCRETE STEEL REINFORCED SEPTIC TANKS AND

PRECAST CONCRETE STEEL FIBRE REINFORCED SEPTIC TANKS6.1 Scope ................................................................................................................................ 266.2 Materials........................................................................................................................... 266.3 Concrete............................................................................................................................ 266.4 Testing.............................................................................................................................. 276.5 Manufacture...................................................................................................................... 276.6 Thickness of tank components........................................................................................... 296.7 Reinforcement................................................................................................................... 306.8 Provision of fittings, partitions and their assembly ............................................................ 31

7 CAST-IN-SITU CONCRETE SEPTIC TANKS7.1 Scope ............................................................................................................................... 327.2 Performance...................................................................................................................... 327.3 Materials........................................................................................................................... 327.4 Design .............................................................................................................................. 327.5 Marking............................................................................................................................ 32

8 REINFORCED CEMENT MORTAR SEPTIC TANKS8.1 Scope and general ............................................................................................................. 338.2 Performance...................................................................................................................... 338.3 Manufacture...................................................................................................................... 33

9 GLASS FIBRE-REINFORCED PLASTIC SEPTIC TANKS9.1 Scope ................................................................................................................................ 349.2 Performance requirements................................................................................................. 349.3 Design .............................................................................................................................. 349.4 Manufacture...................................................................................................................... 359.5 Testing.............................................................................................................................. 38

10 PLASTIC (POLYOLEFIN) SEPTIC TANKS10.1 Scope ............................................................................................................................... 4010.2 Performance requirements................................................................................................. 4010.3 Design .............................................................................................................................. 4010.4 Manufacture...................................................................................................................... 4110.5 Testing.............................................................................................................................. 42

APPENDICES

A Referenced documents ................................................................................................................. 44B Septic tank capacities................................................................................................................... 47C Test of the manufacturer’s instructions for the installation

of fittings in a sound and watertight manner ................................................................................ 48D Determination of the resistance of a partition to a hydrostatic head (pumpout test)....................... 49E Determination of watertightness................................................................................................... 50F Determination of resistance to lateral load - hydraulic test method............................................... 53G Determination of resistance to lateral load - point load test method.............................................. 55H Determination of resistance to top loading .................................................................................. 58I Installation of septic tanks............................................................................................................ 61J Determination of the hardness of glass fibre-reinforced plastic composites................................... 63K Determination of the impact resistance of moulded polyolefin septic tanks................................... 64

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PageTABLES

6.1 Concrete characteristics ............................................................................................................... 276.2 Methods for manufacture ............................................................................................................. 286.3 Minimum concrete thickness ....................................................................................................... 296.4 Minimum concrete cover ............................................................................................................. 306.5 Minimum quantity of steel reinforcement measured as cross-sectional area.................................. 31B1 Conventional septic tank capacities in litres................................................................................. 47

FIGURES

3.1 Typical arrangement of a septic tank............................................................................................ 203.2 Typical UPVC fittings ................................................................................................................. 213.3 Typical alternative arrangement for precast concrete tanks

with a ‘U’-section scum baffle (outlet only).................................................................................. 213.4 Typical installation arrangement of inlet and outlet fittings.......................................................... 223.5 Typical gas baffle designs ............................................................................................................ 23E1 Watertightness test arrangement for horizontal and vertical tank ................................................. 52H1 Typical load testing set-up ........................................................................................................... 60

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STANDARDS AUSTRALIA/STANDARDS NEW ZEALAND

Australian/New Zealand Standard

On-site domestic wastewater treatment unitsPart 1: Septic tanks

1 GENERAL

1.1 ObjectiveThe objective of this Standard is to identify performance requirements and performance criteria for septictanks, to specify technical means of compliance and to provide test specifications that will enable septictanks to be manufactured to comply with the performance requirements and criteria.

C1.1Performance requirements and criteria for septic tanks are found in Section 2. Sections 3 onwards cover‘means of compliance’ and testing for materials currently used to manufacture septic tanks.

1.2 ScopeThis Standard covers the manufacture of conventional septic tanks and their associated fittings for thetreatment of domestic wastewater only. This range of tanks typically is designed to cater for:

All-waste (Blackwater + Greywater)Blackwater onlyGreywater (with or without kitchen waste included) only

and asHolding tanks (collection wells).

Septic tanks covered by this Standard are suitable for a flow of domestic wastewater of up to 14,000 litresper week.

C1.2This flow limit represents an average daily flow of 2000 litres, being from up to 10 persons in a singleresidence, or an institutional or commercial facility which may have a varying 7 day or 5 day operationaveraged out over a full week.

1.3 ApplicationThis Standard is intended for use by consultants, designers, manufacturers, certifying bodies, installers andregulators.

1.3.1 GeneralThis Standard covers only the purpose and requirements of septic tanks and associated fittings. It does notcover the drainage systems leading to the tank, (refer to AS/NZS 3500.2), nor the effluent disposal systemsassociated with septic tanks, (refer to AS/NZS 1547, (in course of preparation).)

1.3.2 Conventional designs and materialsTraditionally certain materials, designs and techniques have been used and have become established. Thematerials and associated designs shown in Sections 6 to 10 of this Standard have been proven through useand are presented as examples of solutions that are a means of compliance with the provisions of thisStandard.

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1.3.3 Non-standard materials, installations or designsThis Standard does not preclude the manufacture of septic tanks from any material, or in any unusualdesign, or installation in any non-standard fashion, provided that the completed product and itsinstallation meets the performance requirements and performance criteria given in Section 2 of thisStandard.

C1.3.3It may be necessary to obtain and supply evidence of third party certification or opinion from people ororganisations recognised as having the authority to do so before a regulatory authority will accept a newmaterial or design.

1.3.4 Operation and maintenanceSeptic tank systems need maintenance and regular desludging. Operation and maintenance requirementsare covered in AS/NZS 1547 (in course of preparation).

1.4 Legislation

1.4.1 This Standard shall be read in conjunction with the by-laws and regulations of the regulatoryauthorities in Australia, and of the New Zealand Building Code in New Zealand.

1.4.2 AustraliaThe collection and treatment of domestic wastewater is the responsibility of the regulatory authority.

1.4.3 New Zealand Septic tank systems and associated land application areas come within the description of a building inSection 3 of the Building Act 1991. The performance requirements of systems that store and treat liquidwaste are given in New Zealand Building Code contained in the First Schedule of the BuildingRegulations 1992.

Septic tanks constructed to this Standard meet the requirements of the New Zealand Building Code inrespect of:

Clause B1 StructureClause B2 DurabilityClause G14 Industrial Liquid Waste

Through the Resource Management Act, Regional Councils will have established a regional plan whichwill control the nature of effluent released to the environment. Territorial authorities will either giveconsent to install a system or will advise if a special resource consent is required.

1.5 Referenced documentsA listing of referenced documents is to be found in Appendix A.

1.6 DefinitionsFor the purpose of this Standard, the definitions below apply:

ACCESS OPENING means an opening in the top surface of the tank fitted with a cover which isremovable to allow access for desludging and for visual inspection of the interior of the tank and contents.Access openings are not intended to allow people to enter a tank.

ANCHORAGE means a device/technique for holding the tank in the ground against hydrostatic upliftpressures.

BLACKWATER means wastes discharged from the human body either direct to a vault toilet or through awater closet (flush toilet) and/or urinal.

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CAPACITY means the volume of the tank below the invert of the outlet.

COLLECTION WELL (see HOLDING TANK)

CURE means the chemical reaction resulting in the final product. It may be effected at ambienttemperature or at an elevated temperature.

DAILY FLOW means the daily flow to the septic tank.

DESLUDGING means removal of the accumulated sludge and scum from a septic tank.

EFFLUENT means the liquid discharged from a wastewater treatment process.

EXTENSION means a structure used to bring the access or inspection cover to ground level.

FOUL WATER (see WASTEWATER)

GAS BAFFLE means a device, usually a simple deflecting plate, installed internally on the outlet of aseptic tank, or the outlet of a second chamber, to prevent gas borne solids passing from the tank into theeffluent land application system.

GEL-COAT means, for glass fibremanufacture, the thin layer of unreinforced resin on the surface of alaminate. The gel-coat covers the fibre of the reinforcement, protects the bond between resin andreinforcement, and provides special surface properties. It may be pigmented.

GREYWATER means the domestic wastes from baths, showers, basins, laundries and kitchens specificallyexcluding water closet and urinal wastes. Greywater does not normally contain human wastes unlesslaundry tubs, or basins are used to rinse soiled clothing or baby's napkins.

HOLDING TANK means a tank used for holding domestic wastewater prior to pumping out (sometimescalled COLLECTION WELL).

HYDROSTATIC FLANGE means a horizontal projection on the wall of the septic tank designed toprevent the tank being forced out of the ground by hydrostatic pressure in areas having a high water table.Sometimes called an anchor collar, or ground retention lip.

INLET FITTING means a device that allows a connection to be made between the drainage systemcarrying the wastewater and the septic tank.

INSPECTION OPENING means opening in the top surface of the tank which allows for inspection ofthe inlet or outlet fitting.

INVERT means the lowest point of the internal surface of a pipe.

LAMINATE means, for glass fibremanufacture, the set layer or layers of reinforcement impregnated withpolyester or other resin forming a thick structural membrane. The laminate does not include the gel-coat.

LAND APPLICATION means the application of effluent to areas of land for further treatment.

LATERAL LOAD means the load applied sideways onto a buried tank due to the combined effects of soil,water and traffic.

LAYING-UP means, for glass fibre manufacture, a process of applying or producing laminates in positionon a mould prior to cure.

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OUTLET FITTING means a device that allows a connection to be made between the outlet of the tank andthe drainage system that conducts the effluent away for further treatment.

PARTITION means an internal wall which may or may not permit the passage of liquid and solid wastebetween compartments within the septic tank.

PERFORMANCE REQUIREMENTS means the functions that a system has to perform in order to operateas defined

PERFORMANCE CRITERIA means the qualitative or quantitative description of the performancerequirements.

PRETREATMENT SYSTEM means a system in which wastewater is partially treated before dischargeinto the septic tank.

REGULATORY AUTHORITY means the authority which is empowered by statute to be responsible formanaging/controlling domestic on-site wastewater.

SCUM means the floating mass of wastewater solids buoyed up by entrained gas, grease or othersubstances which form an accumulating layer on the liquid surface inside the septic tank.

SEPTIC TANK means a single or multiple chambered tank through which wastewater is allowed to flowslowly to permit suspended matter to settle and be retained, so that organic matter contained therein can bedecomposed (digested), by anaerobic bacterial action in the liquid. The term covers tanks used to treatwastewater, greywater and blackwater.

SERVICEABLE LIFE means the period of time in which with only normal and routine maintenance, theseptic tank and associated fittings perform satisfactorily without failure.

SEWAGE means any wastewater, including all faecal matter, urine, household and commercialwastewater that contains human waste.

SLUDGE means the semi-liquid solids settled from wastewater in septic tanks.

SOLIDS means material in the solid state.

VENT means a device, usually a pipe, which allows odours to be removed from the tank.

WASTEWATER means the spent or used water of domestic or commercial origin which containsdissolved and suspended matter. (NOTE: Wastewater is defined as FOUL WATER in the New ZealandBuilding Code.)

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PERFORMANCE

2 PERFORMANCE REQUIREMENTS AND PERFORMANCE CRITERIA

2.1 ScopeThis section of the Standard specifies the performance requirements and performance criteria for septictanks and associated fittings.

2.2 Function and context of use

2.2.1 Function The function of a septic tank is to provide a relatively still zone of adequate size for the treatment of alldomestic wastewater at all flow rates from a household, or institutional or commercial facility. Scum, andsolids capable of settling, are separated from the wastewater flow. The solids are retained, digested andconsolidated between maintenance operations. The tank design allows for the liquid above the settledsolids (sludge) and below the scum layer to be either discharged to a land application system or to beremoved for disposal in some other manner, and for essential regular desludging to be carried out so thatthe volume for storage and treatment of wastewater is maintained.

2.2.2 Context of use

2.2.2.1 Septic tanks are either installed in the ground or freestanding in the open air. In these situations,they are exposed to the effects of the weather, internal loads/pressures, external loads/pressures, and anyground movement. In addition corrosion of the tank material is possible internally from the wastewater,and externally from the surrounding environment.

2.2.2.2 When installed in the ground, the top surface of the tank is either placed at or just above theground surface; (so that inspection and access covers are readily accessed and ingress of surface water isprevented), or the tank is installed deeper. When the tank is installed deeper, provision is made for awatertight vertical extension to be installed above the access and inspection openings to hold the accessand inspection covers at or just above finished ground level.

2.3 Performance requirements

2.3.1 GeneralThe tank and associated fittings and extensions shall be constructed of durable materials. The tank shall bewatertight, be capable of withstanding loads imposed on its roof and walls, and shall be constructed andinstalled so that flotation will not occur in areas of high water-table level or when the tank is emptied.

2.3.2 Septic tanksSeptic tanks shall be constructed:

(a) With capacity for the settlement of solids from the design wastewater flow;

(b) To allow for scum and sludge retention between desludging operations;

(c) To allow entry of waste with the minimum of disturbance to surface layers under normal operatingconditions;

(d) To prevent the direct flow of wastewater between inlet and outlet;

(e) To avoid the likelihood of blockage;

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(f) So that the entire structure of the tank and its associated inspection and access covers and/orextensions, is integrally sound and penetration by roots; entry of ground water; or entry of insects isavoided;

(g) To avoid contamination of soils, groundwater and waterways;

(h) From materials which are resistant or impervious both to the waste contained in the tank and togroundwaters for the serviceable life of the tank;

(i) To avoid the likelihood of foul air and gases creating an odour nuisance and entering buildings;

(j) With access for removal of tank contents;

(k) To reduce the likelihood of unauthorised access by people;

(l) To remain integral for their serviceable life;

(m) To prevent the likelihood of damage from superimposed loads or normal ground movement;

(n) To be able to resist hydrostatic uplift pressures;

(o) To be able to perform adequately with only normal maintenance over their serviceable life.

2.3.3 Serviceable LifeThe serviceable life of a septic tank and associated fittings shall be a minimum of 15 years provided thetank is used and installed in accordance with the manufacturer’s recommendations as defined in thisStandard.

C2.3.3The New Zealand Building Code requires a durability of 15 years for tank envelopes, non-hidden fittings,and other tanks elements having moderate ease of access but which are difficult to replace.

2.4 Performance criteriaAlternative designs or developments must meet the performance requirements of Section 2.3 and theassociated performance criteria in this section.

2.4.1 CapacitiesRecommended minimum capacities for conventional wastewater treatment units are given in Appendix B.

2.4.1.1 All-waste tanksThe capacity of all-waste tanks shall be calculated to provide for at least 24 hours retention for the dailyflow of waste from the premises plus an allowance of 80 litres/person/year of capacity for scum and sludgeaccumulation. It shall be assumed that the tank will be desludged at regular intervals of 3 - 5 years.

C2.4.1.1The allowance for scum and sludge accumulation in the conventional all-waste tank does not allow forextra solids from garbage grinders. The disposal of garbage grinder solids into conventional all-wastetanks is not recommended, see AS/NZS 1547 (in course of preparation).

2.4.1.2 Greywater tanksThe capacity of greywater tanks shall be calculated to provide at least 32 hours combined retention andhydraulic buffering for daily greywater flows, with up to 40 litres/person/year of capacity allowed for scumand sludge accumulation. It is assumed that the tank will require pumpout/desludging at intervals of notgreater than 5 years.

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C2.4.1.2The allowance for scum and sludge accumulation in the conventional greywater tank does not allow forextra solids from garbage grinders. The disposal of garbage grinder solids into conventional greywatertanks is not recommended, see AS/NZS 1547 (in course of preparation).

2.4.1.3 Blackwater tanksThe capacity of blackwater tanks shall be calculated to provide for at least 24 hours retention for dailywater-closet flows, with 50 litres/person/year of capacity allowed for scum and sludge accumulation over a3 - 5 year period when the tank will require pumpout/desludging .

2.4.1.4 Design capacityThe wastewater treatment unit shall be designed to cater for the number of people for which the dwellingis designed.

2.4.2 Flow pathThe flow path of wastewater, measured from the inlet to the outlet, shall be a minimum length of1200 mm.

2.4.3 Inlet fittings and outlet fittingsInlet and outlet fittings shall have a cross-sectional area sufficiently large to allow the passage of solids ofa size expected in the system.

2.4.4 JointsThe joints between a fitting and the wall of a septic tank and between tank components eg. wall and lid,shall have a durable seal, be watertight, and have sufficient integral strength and/or flexibility to maintaina sound structure. The verification test for joints around fittings is given in Appendix C.

2.4.5 PartitionsWhen a septic tank is divided into chambers:

(a) The partition(s) shall be structurally sound and fixed without diminishing the integrity of the tank;

(b) The tank shall be able to be pumped out without the partition collapsing, or permanently deforming.A verification test is given in Appendix D.

2.4.6 Access openings and coversAccess openings are not intended to allow people to enter the tank. Where it is envisaged that a personmust be able to enter the tank, e.g. for the purposes of repairs and maintenance, the access opening sizeshall comply with the appropriate regulations.

(a) Access openings shall be located to allow access for desludging of the chamber(s);

(b) Access openings shall be of sufficient size to allow the desludging mechanism to reach all parts ofthe chamber(s);

(c) Access openings shall either be at or above ground level, or be able to be extended to the finishedground level if installed underground;

(d) Access openings and covers shall provide an effective, durable and watertight seal. They shall be ableto be resealed each time the cover is removed;

(e) Access covers shall be durable and able to withstand superimposed loads;

(f) Access covers shall be secure and shall be designed to prevent removal by children.

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2.4.7 Inspection openings and covers(a) Inspection openings shall be located to give access to the inlet and outlet fittings;

(b) Inspection openings shall have a cross-sectional area of not less than 7,500 mm2;

(c) Inspection openings shall either be at or above ground level, or be able to be extended to the finishedground level if installed underground;

(d) Inspection openings and covers shall provide an effective, durable and watertight seal. They shall beable to be resealed each time the cover is removed;

(e) Inspection covers shall be durable, and able to withstand superimposed loads;

(f) Inspection covers shall be able to be easily removed and replaced.

2.4.8 Extensions(a) Extensions to access and inspection openings shall be fitted so that a watertight seal is achieved;

C2.4.8Requirements for covers to extensions are given in Clauses 2.4.6 and 2.4.7.

(b) Extensions shall be fitted into tank openings so that the extension and the joint are able to withstandexternal loads and pressures.

2.4.9 Watertightness(a) When assembled ready for use the septic tank, fittings and covers shall be watertight;

(b) Test for leakageWhen tested in accordance with Appendix E:

(i) Concrete septic tanks shall not show a leakage rate greater than 4 drops/min from any singlepoint of leakage;

(ii) Plastic or fibreglass tanks shall show no leakage or damp patches.

2.4.10 Integrity

2.4.10.1 The integrity of the tank shall be such that no crack shall develop a width greater than 0.1 mm(approximately) during any stage of production. Further widening or lengthening of any crack shall notoccur during subsequent handling, installation, or use.

C2.4.10.1It is known from experience that cracks of less than 0.1 mm will self-seal with time due to solids build-upfrom the inside of the tank. See Clause 2.4.9.

2.4.10.2Fibre reinforced concrete tanksFor tanks made of concrete reinforced with fibres, the verification test for integrity is ASTM C 1018.

C2.4.10.1Further details of the test and criteria for integrity are given in Clause 6.3.3.

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2.4.11 Loads on tanks

2.4.11.1GeneralTanks shall be designed and constructed to resist loads incurred during transport and installation. If buriedin the ground, tanks shall resist lateral and top loads, uplift loads from groundwater, and where applicablesuperimposed loads from vehicular traffic. Freestanding tanks shall resist snow loads and shall beanchored against ground movement or seismic loads if such requirement is applicable.

2.4.11.2Integrity during handling or installationThere shall be no structural failure when the tank is lifted, or is moved during installation.

Any cracking shall be limited to that defined in Clauses 2.4.9 and 2.4.10.

Verification test:A tank shall be selected that matches the manufacturer’s nominated delivery age. The tank shall be liftedusing the manufacturer’s nominated lifting method and shall show no structural failure or substanialvisible cracking (see above) after being so lifted for 5 minutes.

2.4.11.3Hydrostatic upliftAn installed septic tank shall not move when subjected to uplift forces generated by surrounding groundwater.

2.4.11.4Lateral loadsSeptic tanks shall be designed so that there shall be no structural failure or undue distortion due to externalhydrostatic ground water and soil loading of 6.6 kPa/m depth.

Account shall be taken of any loads imposed on the tank structure as a result of the technique used toanchor the tank in the ground.

Verification test methods are given in Appendix F and in Appendix G. Either test may be used.

2.4.11.5Top LoadsSeptic tanks shall be designed to withstand a top load of 5kN. The verification test is Appendix H.

In addition, there shall be:

(i) no cracking in excess of that permitted by Clauses 2.4.9 and 2.4.10,

(ii) no other failure.

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MEANS OF COMPLIANCE

SECTIONS 3 TO 10 OF THIS STANDARD PROVIDE GENERAL REQUIREMENTSAND ALTERNATIVE MEANS OF COMPLIANCE WITH THE PERFORMANCEREQUIREMENTS OF SECTION 2

Sections 3 to 10 cover the manufacture of conventional septic tanks in various materials.

Sections 3, 4, and 5 cover general requirements common to all tanks.

Sections 6 to 10 cover material-specific manufacture of tanks, and are intended to be used for third partyaudit/certification purposes.

NOTE: These means of compliance sections are only a way of achieving the objectives of the Standard.Non-standard materials, installations and designs shall meet the performance requirements andperformance critieria of Section 2.

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3 GENERAL REQUIREMENTS OF CONVENTIONAL SEPTIC TANKS

3.1 ScopeThis section of the Standard specifies general requirements of conventional septic tanks, fittings,access/inspection provisions, partitions and extensions that will be a means of compliance to theperformance requirements of Section 2 of this Standard. It contains some performance requirements whichallow for new materials, forms of construction etc.

3.2 Septic tank capacitiesThis standard does not specify minimum capacities for septic tanks. Recommended minimum capacitiesfor conventional systems are given in an informative appendix, Appendix B.

3.3 Materials durabilityAll materials used to manufacture septic tanks and their fittings shall have a serviceable life of at least15 years.

C3.3The ultimate durability of some materials is unknown. Accelerated test results are difficult to relate toactual in-service conditions. The use of new materials or formulations is usually justified on the basis oflong term testing, experience, and assessment against existing similar materials. This type of evidence fordurability should be available to and retained by the manufacturer.

3.4 DesignThe completed design shall meet the performance requirements of Section 2.

3.4.1 Tank Figure 3.1 shows two typical arrangements of the parts of a septic tank.

3.4.2 Tank chambersThe tanks may be of single or multi-chamber configuration.

C3.4.2For twin chamber septic tanks, the ratio of the volume of upstream chamber to the downstream chamber isrecommended to be 2:1.

3.4.3 Handling and transportSeptic tanks shall be able to be handled, transported and installed in accordance with the manufacturer’sinstructions without damage occuring. See Clause 2.4.11.2.

3.4.4 AnchorageIn situations when flotation due to hydrostatic uplift from a high water-table is possible, the septic tankshall be provided with a means of being anchored. This may be by use of ‘extensions’ attached to the tankor by other proven means of holding the tank down, details of which shall be provided by the tankmanufacturer with the installation instructions.

3.4.5 Vehicular loadsTanks that will be subjected to top loading from vehicular traffic (e.g. tanks installed underground) shallbe designed to carry the expected loads. The tank lid shall be subject to engineering design and acertificate verifying the load-carrying capacity shall be provided with the tank lid.

3.5 Inlet fittings and outlet fittings

3.5.1 Performance Performance requirements covering inlet and outlet fittings are given in Section 2.

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3.5.2 DesignThe designs requirements of the inlet and outlet fittings are:

(a) To reduce short-circuiting of liquid between inlet and oulet;

(b) To allow clearance of any internal blockage;

(c) To ensure that solids that form the scum layer do not flow through the outlet.

3.5.2.1 ConfigurationTwo types of fittings are shown in Figures 3.2, and 3.3. These are based on:

(a) A fitting formed using a ‘T’ shaped pipe junction, (Figure 3.2) and

(b) A manufactured baffle that is sealed on to the tank wall (Figure 3.3).

3.5.2.2 Size Typical minimum dimensions for fittings are shown in Figures 3.2 and 3.3.

3.5.2.2.1 Internal dimensions(a) The inlet and outlet fittings of conventional septic tanks shall be capable of passing a 90 mm

diameter sphere.

C3.5.2.2.1(a)The inlet pipe nominal size is, typically, 100 mm diameter. Pipe sizes smaller than 100 mm maybe used but only if there is a pretreatment system that changes the nature or size of the solids.

The outlet pipe nominal size is also, typically, 100 mm diameter.

(b) Any reduction in size of the outlet pipe shall be achieved in the pipework external to the tank.

C3.5.2.2.1(b)Reduction of this size is possible and could be achieved by improving the quality of the outgoingeffluent e.g. by use of filters.

3.5.2.2.2 External dimensionsFor effective performance several minimum dimensions are identified:

(a) The inlet and outlet fittings shall extend to not less than 170 mm above the invert of the outlet(the tank liquid level). See Clause 3.6.2.2.

C3.5.2.2.2(a)This is to prevent scum spilling into the inlet or outlet.

(b) i) The fittings shall extend downwards to be not less than 75 mm below the expected depth of scum after 3 years use.

ii) The outlet fitting shall extend downwards for a suffient depth to minimize the flow of any grease, fat or scum through the outlet pipe.

C3.5.2.2.2(b)The conventional length of fitting is a depth of 205 mm below the invert of the inlet, and 330 mmbelow the invert of the outlet.

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3.6 Position of inlet and outlet fittings in tank

3.6.1 Inlet pipeThe position of the inlet fitting inlet pipe below the tank rim or tank top shall be governed by the depth ofcover that is intended to be used when installing the tank. This depth of cover is specified in AS/NZS3500.2.2, and takes into account the location of the pipe in terms of vehicular traffic above it.

C3.6.1For installation in areas not subject to vehicular traffic AS/NZS 3500.2.2 currently requires a 300 mmdepth of cover for pipes (not made of iron) measured from the finished surface to the top of the pipesocket. This depth may only be reduced by the use of concrete, brick or paving in conjunction with 50 mmof overlay according to AS/NZS 3500.2.2.

3.6.2 Inlet and outlet fittings

3.6.2.1 Inlet and outlet fittings shall be installed so that:

(a) There is a fall between the invert of the inlet and the invert of the outlet of not less than 50 mm;

(b) The top of the fitting (or baffle) is not less than 50 mm below the tank rim or roof, whichever is thelower.

These requirements are shown in Figure 3.4.

3.6.2.2 The requirements of Clauses 3.5.2.2.2(a) and 3.6.2.1 lead, as minimum dimension, to the invertof the inlet being not less than 170 mm and the invert of the outlet being not less than 220 mm below theunderside of the lid, roof or tank rim of the septic tank (whichever is the lowest point), at a point directlyabove the intlet or outlet.

3.7 Gas bafflesA gas baffle is a device designed to prevent the carry-over of gas-borne solids through the outlet. Its use isrecommended. Typical designs are shown in Figure 3.5.

3.8 Partitions

C3.8Partitions are optional. They have the potential to improve the quality of effluent by preventing carry-over of solids by providing control of short-circuiting of the flow of waste. Partitions allow the tank to bedivided to provide a desired chamber size ratio and they assist with hydaulic buffering. Partitions may bemanufactured separately, or be integral with the tank, and so may improve long-term structural andhydraulic integrity.

When installed:

(a) A partition is normally positioned at 900 to the liquid flow;

(b) The partition shall have a means of allowing fluid to transfer across it which reduces/prevents thetransfer of any solid matter. See Figure 3.1;

C3.8(b)Any opening in the partition for this purpose has traditionally been a rectangular area of 15000 m2

located at half the operating depth.. However, the alternate H shaped pipe system operates with apipe diameter of 100 mm and an area of 7,850 mm2.

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(c) The partition shall be able to withstand pump-out. See Clause 2.4.5(b) and Appendix D;

C3.8(c)Over time loosely fitting partitions will become 'sealed' into position. During pump-out/desludgingthis 'seal' may hold or may break releasing fluid into the chamber being pumped out and thusrelieving the hydrostatic head against the partition. However, this effect cannot be assumed to takeplace in all cases, and partitions must be able to show that they can withstand any effects from thepump-out operation as specified in Clause 2.4.5.

3.9 VentsVenting of septic tank systems shall be in accordance with AS/NZS 3500.2.

3.10 Access openings and covers

3.10.1 Access openings are typically 500 mm x 450 mm rectangular or 500 mm diameter circular, locatedover the tank partition.

C3.10.1The size and siting of one or more access openings are governed by the size of the desludging equipmentand the need to be able to desludge all chambers in a tank.

3.10.2 Access covers shall be designed to prevent removal by children.

3.10.3 A corrosion-resistant means of lifting the covers shall be provided.

3.11 Extensions

C3.11The burial of septic tanks so that the access and inspection covers become situated below ground level isforbidden by some Regulatory Authorities. Other Authorities allow burial but usually with the expectationthat this would be 300 - 500 mm below ground level at the most and that extensions are used to bring theaccess and inspection covers up to ground level. In the latter case, the extensions are typically short andin one piece. The following requirements apply to these types of extension.

3.11.1 PerformancePerformance requirements of extensions are given in Section 2.

3.11.2 Installation(a) Extensions shall be fitted and made watertight against ingress of water in accordance with

instructions provided by the manufacturer;

(b) The installed extensions shall withstand any normally expected loads and pressures. In meeting theserequirements, the manufacturer shall base the choice of materials, the design and the installationinstructions for extensions, on a certificated report from a structural engineer.

3.12 MarkingTanks and components of tanks separately manufactured shall be marked as described in Section 4.

3.13 InstallationRecommendations for installation are given in Appendix I.

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FIGURE 3.1 TYPICAL ARRANGEMENTS OF A SEPTIC TANK(Diagrammatic only)

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NOTE – All dimensions are minimum and in millimetres

FIGURE 3.2 TYPICAL UPVC FITTINGS(Diagrammatic only)

NOTE: All dimensions are minimum and in millimetres

FIGURE 3.3 TYPICAL ALTERNATIVE ARRANGEMENT FOR PRECAST CONCRETE TANKSWITH A ‘U’-SECTION SCUM BAFFLE (OUTLET ONLY)

(Diagrammatic only)

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FIGURE 3.4 TYPICAL INSTALLATION ARRANGEMENT OF INLET AND OUTLETFITTINGS

(Diagrammatic only)

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FIGURE 3.5 TYPICAL GAS BAFFLE DESIGNS(Diagrammatic only)

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4 MARKING OF SEPTIC TANKS

4.1 ScopeThis section of the Standard defines the minimum marking requirements for septic tanks.

4.2 GeneralMarking is necessary to provide a traceable route to the manufacturer and to the date of manufacture.Marking is often a prerequisite for quality assessment.

4.3 Requirements

4.3.1 Minimum informationTank marking shall include, as a minimum, the following information:

(a) The manufacturer’s name or trademark;

(b) The date of manufacture;

(c) The capacity in litres;

(d) Identification of the inlet to the tank;

(e) Top load limitations;

(f) Weight of tank.

Information required by (a) (c) and (e) shall be the on the top external face of the tank adjacent to the inletfitting.

Other information shall be marked either on the top external face, or on the tank itself adjacent to the inletfitting.

4.3.2 Other componentsAny other component of the tank that may be separately manufactured and subsequently assembled withthe tank e.g. a lid, access cover or partitions shall be marked with the date of manufacture.

4.3.3 Permanence and visibilityAll marking shall be permanent, legible, and clearly visible when the tank is installed.

C4.3.3This might be achieved through the use of stencilling, or embossing by incorporation in the resin ormoulding.

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5 TESTING REQUIREMENTS OF SEPTIC TANKS

5.1 ScopeTwo forms of tests are identified in this Standard, type tests and routine manufacturing process qualitycontrol tests.

5.2 Type testing

5.2.1 Section 2.4 specifies a series of type tests which all septic tanks shall be capable of passing. The testsand the relevant Clauses and Appendices are set out below:

(a) Test for the installation of fittings in a sound and watertight manner. See Clause 2.4.4Appendix C;

(b) Pump-out tests for tanks with partitions. See Clause 2.4.5(b) Appendix D;

(c) Method of testing the watertightness of tanks. See Clause 2.4.9 and Appendix E;

(d) Integrity test for fibre reinforced concrete tanks when fibre load is less than 75 kg/m3. See Clause2.4.10.2 and 6.3.3;

(e) Resistance to handling and installation loads. See Clause 2.4.11.2;

(f) Resistance to lateral loads. See Clause 2.4.11.4 and Appendix F and G: either test may be used;

(g) Resistance to a top load. See Clause 2.4.11.5 and Appendix H.

In addition fibre-reinforced tanks shall meet the integrity test specified for concrete fibre-reinforced tanks.See Clause 2.4.10.2.

Type testing shall be carried out on initial production or whenever a change is made that may affect theperformance of the finished tank.

C5.2.1Typically this would be when there is a totally new design, a change of component design, a change ofmaterials, techniques of production, etc.

5.2.2 Systems developed to meet the Section 2 requirements for the watertightness of covers and the properinstallation of extensions may require further (specially developed) type testing.

5.3 Routine quality testingRoutine quality control testing shall be carried out to ensure that a consistent quality of product ismaintained. These tests are identified in the relevant material-based sections of this Standard.

C5.3Type tests in this standard may also be suitable for use as routine quality control tests.

5.4 Quality certificationIf it is intended to seek certification against this Standard the testing regime (i.e. type of test, number ofsamples, and frequency of testing) for both type testing and routine quality control testing shall beestablished in consultation with the quality audit organisation or certification body involved.

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6 PRECAST CONCRETE STEEL REINFORCED SEPTIC TANKS AND PRECAST CONCRETE STEEL FIBRE REINFORCED SEPTIC TANKS

6.1 ScopeThis section sets out the requirements for conventional septic tanks made from concrete reinforced withsteel or steel fibre.

6.1.1 GeneralPerformance requirements and performance criteria are given in Section 2 of this Standard. Section 3gives further information about septic tank fittings and accessories.

6.2 Materials

6.2.1 CementCement for use in concrete septic tanks shall comply with AS 3972 or NZS 3122.

6.2.2 AggregateAggregate for use in concrete shall comply with AS 2758.1 or NZS 3121. The maximum aggregate sizeshall be chosen that will permit flow of the concrete into thin wall sections and around close-spacedreinforcement.

6.2.3 AdmixturesAdmixtures shall conform to AS 1478 or NZS 3113. Calcium chloride shall not be used.

6.2.4 Steel reinforcement

6.2.4.1 Steel bars, fabric and wireSteel bars, fabric and wire shall be as specified in AS 1302, AS 1304 and AS 1303, or NZS 3402,NZS 3422 and NZS 3421 respectively.

6.2.4.2 Steel fibreSteel fibre shall have a minimum tensile strength of 600 MPa.

6.3 Concrete

6.3.1 GeneralConcrete, (including steel fibre reinforced concrete), shall be of adequate strength to allow stripping fromthe mould, handling, transporting to site and placing in position without incurring cracking which wouldimpair the effectiveness of the unit.

6.3.2 SpecificationThe characteristics of the concrete used in the manufacture of precast septic tanks shall be as given inTable 6.1.

6.3.3 Fibre reinforced concreteWhen tested according to ASTM C 1018 the fibre reinforced concrete shall achieve a minimum flexural(first crack) strength of 5.5 MPa at 28 days, and either:

(i) A minimum mean toughness index I5 value of 4.75, or

(ii) A minimum mean toughness index I30 value of 20.0 and

an I30 - I10 value of 12.0 minimum.

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TABLE 6.1 CONCRETE CHARACTERISTICS

Type of septic tankSteel

reinforcementCompressive strength

minimum

At 28 d Prior to delivery

Cylindrical or rectangular

Cylindrical

Bars, fabricor wire

Fibre

MPa

32#

35

MPa

25

30

# Most appropriate compressive strength specification in New Zealand is 35 MPa.

6.4 Testing(See Section 5: Testing requirements of septic tanks)

6.4.1 Type testing

6.4.1.1 Steel fibre concrete(a) Steel fibre reinforced concrete with a steel fibre content of less than 75 kg/m3 shall be type tested to

achieve the requirements of Clause 6.3.3.

(b) If the steel fibre specification changes in a mix that contains less than 75 kg/m3 of steel fibre, or thesteel content is changed to be less than 75 kg/m3, then the product shall be retested as required byClause 6.3.3.

6.4.1.2 Completed TankType testing of completed septic tanks shall be carried out as required by Section 2 of this Standard. Allseptic tanks shall be capable of complying with these type tests.

6.4.2 Routine quality control testingManufacturers shall establish tests on tank materials and finished tanks and a frequency of testing that willdemonstrate that a consistent quality of product is being produced.

For tanks made in accordance with the requirements of this Section of the Standard the routine qualitycontrol tests shall, as a minimum, be to determine the compressive strength of the concrete, and thewatertightness test.

6.4.2.1 Compressive strengthWhen tested in accordance with AS 1012.9 or NZS 3112 Part 2, the 28 day compressive strength of eachtest specimen shall be not less than that given in Table 6.1.

Test specimens shall be either made and cured (see AS 1012.8); or secured from hardened concrete(see AS 1012.14).

6.4.2.2 Watertightness Watertightness testing shall be undertaken in accordance with the procedures in Appendix E.

6.5 ManufactureThe manufacturing process shall be carried out in a controlled manner to produce a consistent productchecked by a quality assurance process.

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6.5.1 MethodsMethods currently used for the manufacture of components for precast, steel or steel fibre reinforcedconcrete septic tanks are given in Table 6.2.

The technique of manufacture shall comply with AS 3600 or NZS 3109.

TABLE 6.2 METHODS FOR MANUFACTURE

Type of septictank

Component

Wall(s) Base Lid End

Cylindrical withvertical axis Centrifugally cast

or cast andvibrated

Cast and vibratedseparately forlater structuralconnection to thewall with awatertight joint orcast integrallywith the wall andvibrated

Cast and vibratedseparately, in oneor two sections,for laterconnection toeach other andthe wall with awatertight joint

Not applicable

Cylindrical withhorizontal axis Centrifugally cast

or cast andvibrated

Not applicable Not applicable Cast and vibratedseparately forlater structuralconnection to thewall with awatertight joint

Rectangular: Cast integrally and vibrated As for cylindricalwith vertical axis

Not applicable

6.5.1.1 Cylindrical wallsThe walls of circular precast concrete tanks shall be reinforced with hard drawn steel bars, fabric or wire,or steel fibres that comply with Clause 6.7. The reinforcing shall be formed into a cage consisting of areinforcement fabric, or a circumferential helix held in shape with longitudinal wires.

6.5.1.2 Tank endsEnds of tanks (lids and bases) may be cast integrally with the walls or cast separately. If cast separately thetank end shall be securely jointed, keyed or mortared to the walls of the tank to provide a watertight unit.

6.5.1.3 Steel fibre reinforced tanks

6.5.1.3.1 Mixing of steel fibreThe concrete shall be batched and mixed according to the fibre supplier’s recommendations anddirections which will lead to a uniform distribution of the fibre throughout the mix.

C6.5.1.3.1The appearance of fibre balls in the mix is evidence of segregation or poor mixing.

6.5.1.3.2 Concrete finishAny fibres which are left protruding from the concrete surface after casting shall be removed flush withthe tank wall.

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6.5.1.3.3 Fibre contentIf the tank section thicknesses are greater than the minimum values shown in table 6.3, then the fibrecontent may be reduced in proportion to the increase in section thickness provided the original steel fibrereinforced concrete mix complied with Clause 6.4.

6.6 Thickness of tank componentsThe wall thickness of tank components shall be sufficient to produce a tank of adequate strength to resistdamage during handling, transporting, installation, and during service. A critical consideration is thatthere shall be a minimum cover of concrete over the reinforcement to assist in corrosion protection of thesteel. See Clause 6.7.

The minimum concrete thickness of components of precast concrete septic tanks shall be as given inTable 6.3.

TABLE 6.3 MINIMUM CONCRETE THICKNESS

Minimum concrete thickness

Type ofseptic tank

Steelreinforcement

Wall(s) Base Lid End

Centri-fugally

cast

Cast andvibrated

Cylindricalwith

vertical axis

Bars, fabric andwire

Helical cage+

Fibre

50

55

30

60

55

40

mm

65

65

40 or 65*

mm

65

65

65

mm

NA

NA

NA

Cylindricalwith

horizontalaxis

Bars, fabric andwire

Helical cage+

Fibre

50

55

30

60

55

40

NA

NA

NA

NA

NA

65

65

NA

40 or 65*

Rectangular Bars, fabric andwire

NA 75 75 65 NA

* The lower value applies when cast integrally with the wall(s), and the higher value, when cast andvibrated separately to be keyed, at the time of its manufacture, to the wall with a watertight joint.

+ Helical cage refers to a circumferential cage made from hard drawn steel wire.NA Not applicable

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6.7 Reinforcement 6.7.1 CoverThe minimum distance between the face of steel reinforcement and the nearest concrete surface of aprecast septic tank shall be as given in Table 6.4.

TABLE 6.4 MINIMUM CONCRETE COVER

Minimum cover

Type of septictank

Steel bars, fabric and wire Steel fibre

Wall(s)Base, lid All components

Centrifugally cast Cast and vibrated or end

Cylindrical

Rectangular

mm

15

Not applicable

mm

20

20

mm

20

20

No limitation

No limitation

6.7.2 Corrosion protectionWhen manufacturing septic tanks using ‘cast and vibrated’ methods, the ends of every non-corrosion-resistant reinforcement support (bar chairs or similar devices) shall be covered/coated with a corrosion-resistant material.

6.7.3 Quantity of reinforcement

6.7.3.1 Steel reinforcementThe quantity and placement of steel reinforcement in the shape of bars, fabric and wire shall comply withAS 3600 or NZS 3109 but in no case be less than given in Table 6.5.

6.7.3.2 Steel fibreSufficient steel fibre shall be incorporated so that either:

(a) The steel fibre content shall be a minimum of 75 kg/m3 of concrete, or

(b) The final mix meets the requirements of Clause 6.4;

C6.7.3.2The amount/quantity of reinforcement incorporated into the tank structure is designed to limit theformation of any cracks to a width of approximately 0.1 mm maximum. It is known from experience thatcracks up to this size will self-seal with time.

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TABLE 6.5 MINIMUM QUANTITY OF STEEL REINFORCEMENT

measured as cross-sectional area in mm2/m*

Type of septic tank

Type of steelreinforcement

Cylindrical,Internal diameter

< 1800 mm#Rectangular

Wall Base, Top andend slabs

Walls andBase

Lid

Fabric

Wire(a) helical

(b) longitudinal

mm2/m

126

126

40

mm2/m

126

Not applicable

Not applicable

mm2/m

188

Not applicable

Not applicable

mm2/m

188

Not applicable

Not applicable

* The values given are for NOMINAL mesh wire sizes and are subject to tolerances specified by theappropriate Standard.

# Cylindrical tanks with internal diameter > 1800 mm to be as specified by a structural engineer.

6.7.4 Lapping of reinforcement

6.7.4.1 Tank endsIf the tank end is cast integrally with the walls the longitudinal reinforcement shall be bent 900 and placedradially into the base or end slab to provide a minimum lap of 150 mm with the base reinforcement.

6.7.4.2 FabricAll fabric lap splices shall be achieved by an overlap of not less than two crosswires.

6.8 Provision of fittings, partitions and their assembly

6.8.1 Inlet and outlet fittings(a) Inlet and outlet fittings may be installed either by the manufacturer prior to delivery of the septic

tank or by the licensed plumber/drainlayer at the time of installation of the septic tank.

(b) When inlet and outlet fittings, access and inspection covers, partition, anchorage device, and anynecessary fasteners are provided separate to the tank for installation on-site then detailed installationinstructions shall be provided by the manufacturer with each tank at the time of despatch.

6.8.2 PartitionsThe permanent fixing of a partition into the septic tank shall be in accordance with the manufacturer’sinstructions and may be carried out on-site at the time of installation of the tank.

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7 CAST-IN-SITU CONCRETE SEPTIC TANKS

7.1 ScopeThis section of the Standard covers the basic requirements of septic tanks made on site (cast-in-situ).

7.2 PerformanceThe performance requirements of Section 2 of this Standard apply.

7.3 Materials

7.3.1 GeneralThe materials used in the construction of concrete cast-in-situ septic tanks shall comply with AS 3600 orNZS 3109. Ready-mixed concrete shall comply with AS 1379 or NZS 3104.

7.3.2 Cast-in-situ concrete tanks shall be structurally sound, internally smooth, and watertight.

7.3.3 Walls and floors shall be rendered using a 1:3 cement:sand mortar to a minimum thicknessof 12 mm.

7.4 Design

7.4.1 Thickness, reinforcement and strength of concrete

7.4.1.1 Floor and wallsThe thickness of concrete floors and walls in a rectangular cast-in-situ concrete septic tank shall be:

(a) Not less than 150 mm of unreinforced concrete having minimum strength of 25 MPa.

(b) Not less than 100 mm of reinforced concrete having a minimum strength of 25 MPa and usingreinforcement as specified by Table 6.5.

7.4.1.2 RoofThe roof of a cast-in-situ concrete septic tank shall be a slab of reinforced concrete, and shall be designedto comply with the requirements of Section 6.

7.4.1.3 Cover to reinforcementThe cover to the reinforcement in a cast-in-situ concrete septic tank for roof slabs, floors, walls, and coversto access and inspection openings, shall be not less than 40 mm.

7.5 Marking

Cast-in-situ septic tanks shall be marked as required by Section 4.

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8 REINFORCED CEMENT MORTAR SEPTIC TANKS

C8.1.2Tolerances in construction must be closely controlled. The manufacture and application of mortar is askilled operation and it is important that high standards of construction are maintained. It is for thesereasons that NZS 3106 requires that construction is only carried out by those able to demonstrate thenecessary skills, usually in a factory environment.

8.1 Scope and general

8.1.1 Scope This section of the Standard is for a reinforced composite system that allows for thedevelopment of high stresses in the composite and less cover over the reinforcement.

8.1.2 General(a) Cement mortar elements of tanks shall be constructed by specialist firms able to demonstrate

satisfactory experience;

(b) Continuous supervision shall be provided as specified in NZS 3106.

8.2 Performance The performance requirements of Section 2 of this Standard apply.

8.3 Manufacture For guidance with design, selection of materials, mortar application and thickness,and testing refer to NZS 3106.

C8Tanks of reinforced cement mortar have been in service in New Zealand for many years. Typically theyare reinforced with layers of very small diameter reinforcing separated by separately applied layers ofhigh strength mortar. Their construction is covered in NZS 3106.

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9 GLASS FIBRE-REINFORCED PLASTIC SEPTIC TANKS

9.1 ScopeThis section of the Standard covers the construction of septic tanks using glass fibre-reinforced resin. Theuse of other fibres or other resins is not excluded provided that the provisions of this section of theStandard are met.

9.2 Performance requirements

9.2.1 GeneralPerformance requirements and performance criteria are given in Section 2 of this Standard. Section 3gives further information about septic tank fittings and accessories.

9.2.2 Performance aspects of the Section 2 requirements that have a greater relevance to glass fibre-reinforced plastic materials are:

(a) The resistance of the septic tank, lid, access opening cover, and the inspection opening cover toultraviolet light degradation;

(b) The design and construction of the tank, lid and access cover to resist installation and inserviceloads;

(c) The provision of the septic tank with a means of anchorage (antifloatation measure) to prevent thetank from moving from its installed position.

9.2.3 Other requirements(a) The surfaces of a septic tank, lid, access opening cover and other components shall be smooth and

impervious to liquids;

(b) All fasteners shall be of durable material, resistant to the corrosive environment, and if inaccessibleshall be effective for the serviceable life of the septic tank. See Clause 9.4.1.4.

9.3 Design

9.3.1 GeneralThe design of a glass fibre-reinforced plastic septic tank shall be such as to prevent deformation andflexing and to take account of:

(a) Internal and external pressures;

(b) Mass of tank and contents;

(c) Localized loads acting at the supports, lugs and other attachments;

(d) Normal loads applied during transport and installation;

(e) Material fatigue;

(f) Soil conditions and expected loading.

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9.3.2 Design basisThe design of glass fibre-reinforced plastic tanks shall be based on the following:

(a) Tank seams and openings shall be designed in accordance with either BS 4994, or PS 15:69;

(b) Tops of tanks and access covers shall be designed in accordance with Clause 9.2.2(b).

9.3.3 AnchorageAll glass fibre-reinforced plastic septic tanks shall be provided with a means of anchorage.

C9.3.3Two typical examples are given below:

(a) Hydrostatic flangeAn L-shaped section constructed not less than 65 mm wide and not less than 4 mm thick which isbonded to the outside circumference of the tank. The flange may be continuous around thecircumference or may be in at least two sections each of not less than 600 mm long and bonded toopposite sides of the tank.

For a vertical cylindrical tank the flange is bonded not more than 300 mm from the base, and for ahorizontal cylindrical tank the flange is situated along the line of the greatest horizontal perimeter.

(Hydrostatic flanges are usually bonded to the tanks under controlled conditions near the site ofinstallation.)

(b) Loops to be affixed at the time of installation.

Each ‘side’ of the tank is held into the ground by a piece of pipe, typically 100 mm PVC sewer gradepipe, attached to the tank by two durable plastic ropes. These ropes are anchored in the rim of thetank and have a loop in the other end at excavation ground level. Both pipes have a length of notless than the diameter of the tank and each is passed through two loops. Backfilling then covers thepipes.

9.4 Manufacture

9.4.1 MaterialsThe materials used in the manufacture and construction of septic tanks shall comply with the following:

9.4.1.1 ResinThe resin shall be polyester resin or equivalent resin that:

(a) Has a minimum heat distortion temperature of 65oC when tested in accordance with ISO 75-3 and iscapable of being used in the manufacture of a laminate that complies with Clause 9.4.2;

(b) Will cure at ambient or higher temperature with the addition of a catalyst and, if necessary,promoters or accelerators used in accordance with the manufacturer’s or supplier’srecommendations, and;

(c) Contains:

(i) Not less than 50% w/w of non-volatile materials;

(ii) No pigment or fillers; and

(iii) Not more than 2% w/w of thixotropic agents.

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9.4.1.2 Reinforcement(a) Glass-fibre

The reinforcing material shall be a suitable grade of glass fibre having a glass finish compatible withthe resin used and complying with BS 3396 Part 3, BS 3496, BS 3691, or BS 3749, as appropriate.

(b) Other reinforcementThe use of non-glass reinforcement is possible provided the finished product meets the testrequirements of Clause 9.5, (excluding Clause 9.5.6.).

9.4.1.3 Gelcoats(a) Polyester

A polyester gelcoat shall be a suitable chemical resistant resin with a minimum heat distortiontemperature of 65oC when tested in accordance with ISO 75-3.

Polyester gelcoats shall comply with the following requirements, as appropriate:

(i) Internal gelcoat:Internal gelcoats shall cure with the addition of a catalyst and if necessary, promoters oraccelerators used in accordance with the manufacturer’s or supplier’s recommendations.

The gelcoat shall be free of any pigment or filler.

Thixotropic agents of up to 3% w/w are permitted.

The gelcoat shall be a minimum of 0.4 mm thick.

(ii) External gelcoat:External gelcoats shall cure with the addition of a catalyst and, if necessary, promoters oraccelerators used in accordance with the manufacturer’s or supplier’s recommendations.

The gelcoat for the tank and cover may contain up to 10% w/w pigment paste.

The cured gelcoat shall be free from cracks, pinholes and surface defects and shall not be lessthan 0.4 mm thick.

(b) Other gelcoatsOther materials used as gelcoats shall meet the test requirements of Clause 9.5.

These gelcoats shall be prepared and applied in accordance with the manufacturer’s or supplier’sinstructions.

9.4.1.4 Fasteners All fasteners shall be of durable material, resistant to the corrosive environment, and be either:

(a) Stainless steel, grade 316 (see AS 1449 or NZS/BS 1449); or

(b) Copper alloy, grade 443 (see AS 2738.2 or NZS/BS 1400); or

(c) a suitable equivalent.

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9.4.2 Manufacturing Process

9.4.2.1 GeneralThe manufacturing process shall be carried out in a controlled manner to produce a consistent productchecked by a quality assurance process.

The method for the manufacture of components for glass fibre-reinforced plastic septic tanks shall be by:

(a) The even application of resin and glass to the mould;

(b) Rolling the lay-up to achieve:

(i) Complete wetting of the fibres;

(ii) Removal of air bubbles from the surface;

(iii) Reduction of air bubbles to diameters not greater than 1.5 mm and to less than 10per 625 mm2; and

(c) Rounding of all internal corners with a radius of not less than 6 mm;

The mass of glass rovings shall be determined continuously as the material is applied.

9.4.2.2 Laminate and thicknessThe composition and thickness of the laminate shall be as follows:

(a) TankThe laminate shall contain not less than 30% glass strands. No fillers or pigments shall be includedin the laminate;

The thickness of the laminate shall be not less than 4 mm. The thickness shall be increased to be notless than 6 mm for a distance of not less than 40 mm from all edges of openings and the edges ofupstands for access and inspection covers. Changes in thickness shall be by smooth transitions.

The external surface of the tanks shall be coated with either a clear layer of catalysed resin or anexternal gelcoat as defined in Clause 9.4.1.3, Section (b), of not less than 0.4 mm thick.

(b) Access opening cover and top of vertical tanksAccess, inspection covers and tops of tanks shall contain not less than 30% chopped glass strands.

The thickness of the laminate shall be not less than 4 mm. This shall be increased to 6 mm within40 mm of any edge.

9.4.2.3 Surface finishThe internal and external surface of the septic tank shall be smooth, unbroken and impervious.

9.4.2.4 Inlet and outlet holesThe inlet and outlet holes shall be cut or formed in the tank wall prior to the septic tank leaving themanufacturer’s premises.

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9.4.3 Provision of fitting, partitions and their assembly

9.4.3.1 Inlet and outlet fittings(a) Inlet and outlet fittings may either be installed by the manufacturer prior to delivery of the septic

tank, or be installed by the licensed plumber/drainlayer at the time of installation of the septic tank.

(b) When inlet and outlet fittings, access and inspection covers, partition, anchorage device, and anynecessary fasteners are provided separate to the tank for installation on-site detailed installationinstructions shall be provided by the manufacturer with each tank at the time of despatch.

9.4.3.2 PartitionsThe permanent fixing of a partition into the septic tank shall be in accordance with the manufacturer’sinstructions and may be carried out on-site at the time of installation of the tank.

9.5 TestingRefer Section 5: Testing requirements of septic tanks.

9.5.1 Type testing

9.5.1.1 Completed tanksType testing of completed septic tanks shall be carried out as required by Section 2 of this Standard againstrelevant appendices, (listed in Section 5, Clause 5.2.1). All septic tanks shall be capable of complying withthese type tests.

9.5.1.2 In addition the following type testing shall be carried out when changes to design, raw materialsor manufacturing process are made.

9.5.1.2.1 Test specimensAll test specimens shall be prepared in accordance with ISO 1268.

9.5.1.2.2 Flexural strength and modulus of elasticityWhen tested in accordance with ISO 178, the flexural strength and modulus of elasticity of each testspecimen shall be not less than 110 MPa and 4830 MPa, respectively.

9.5.1.2.3 Impact resistanceWhen tested in accordance with ISO 179-2, the test specimen shall have no surface cracks visible tonormal or corrected normal vision.

9.5.1.2.4 HardnessWhen tested in accordance with Appendix J, the Barcol hardness number of each test specimen and anypart of each test septic tank shall be not less than 35.

9.5.1.2.5 Water absorptionWhen tested in accordance with ISO 62, the amount of water absorption of each test specimen shall be notgreater than 0.75%.

9.5.1.2.6 Glass fibre contentWhen tested in accordance with ISO 1172, the glass content of each test specimen shall be not less than30% w/w.

9.5.1.2.7 Tensile strengthWhen tested in accordance with ISO R527, the tensile strength shall not be less than 63 MPA.

9.5.1.2.8 Tensile ElongationWhen tested in accordance with ISO R527, the tensile elongation shall not be less than 1.5% minimum.

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9.5.1.2.9 UV light degradationTesting of glass fibre-reinforced plastics for the resistance to U.V. light degradation is usually theresponsibility of the resin/gel-coat manufacturer prior to recommending products and mixes as suitable foroutdoor exposure. See Clause 3.3.

9.5.2 Routine quality control testing

9.5.2.1 GeneralManufacturers shall establish tests on tank materials and/or finished tanks, and a frequency of testing thatwill demonstrate that a consistent quality of product is being produced.

9.5.2.2 Test SpecimenQuality control testing shall be carried out on specimens prepared according to ISO 1268.

9.5.2.3 TestsIt is recommended that the following tests are considered for quality assurance of manufacture:

Laminate thickness measurement

Thickness of gelcoat at time of application

Hardness

Reinforcing fibre content

9.5.2.4 Frequency(a) The frequency of testing will be governed by the needs of any internal quality assurance programme,

or external quality assessment programme.

9.5.2.5 Pass/FailThe test results should meet the criteria set for the tests in this section of the Standard.

9.5.2.6 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of persons/organisation carrying out test;

(b) Identification of the sample tested;

(c) Date of test;

(d) The test results;

(e) Reference to the test method.

Test records shall be kept as required by the quality assurance programme.

(A minimum of ten years is recommended.)

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10 PLASTIC (POLYOLEFIN) SEPTIC TANKS

10.1 ScopeThis section of the Standard covers the construction of septic tanks using polyolefin thermoplastics.

C10.1The two most commonly used polyolefins are polyethylene which is usually rotationally moulded, orpolypropylene which is usually injection moulded.

10.2 Performance requirements

10.2.1 GeneralPerformance requirements and performance criteria are given in Section 2 of this Standard. Section 3gives further information about septic tank fittings and accessories.

10.2.2 Aspects of the Section 2 requirements that have a greater relevance to polyefin plastic materialsare:

(a) The resistance of the septic tank, lid, access opening cover and the inspection opening cover toultraviolet light degradation;

(b) The design and construction of the tank, lid and access cover to resist installation and inserviceloads;

(c) The provision of the septic tank with a means of anchorage (antifloatation measures) to prevent thetank from moving from its installed position.

10.2.3 Other requirements

(a) The surfaces of a septic tank, lid, access opening cover and other components shall be smooth andimpervious to liquids;

(b) Fasteners used in plastic septic tanks shall be manufactured from materials which are durable andresistant to the corrosive environment and if inaccessible shall be effective for the serviceable life ofthe tank. See Clause 10.4.1.2.

10.3 Design

10.3.1 GeneralThe design of a plastic (polyolefin) tank shall be such as to prevent deformation and flexing and to takeinto account:

(a) Internal and external pressures;

(b) Mass of tank contents;

(c) Localized loads acting at the supports, lugs and other attachments;

(d) Normal loads applied during transport and installation;

(e) Material fatigue;

(f) Soil conditions and expected loadings.

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10.3.2 ThicknessThe thickness of the tank walls, base, access opening covers and lids shall be not less than 6 mm.

Polyolefin materials that allow a thinner component to be made shall meet the performance requirementsand tests of this Standard.

10.3.3 AnchorageAll plastic (polyolefin) septic tanks shall be provided with a means of anchorage.

C10.3.3Typical examples are:

(a) Hydrostatic flangeAn integrally moulded flange of similar size to the anchor collar in 10.3.3 (b).

(b) Anchor collar to be affixed at the time of installation:An L-shaped anchor collar section constructed not less than 65 mm wide and not less than 6 mmthick to be fixed to the outside circumference of the tank with durable material protected from thecorrosive environment. The collar may be continuous around the circumference or may be in at leasttwo sections each not less than 600 mm long and fixed to opposite sides of the tank.

For a vertical cylindrical tank the flange is fixed not more than 300 mm from the base, and for ahorizontal cylindrical tank the flange is situated along the line of the great horizontal perimeter.

(c) Loops to be affixed at the time of installationEach ‘side’ of the tank is held into the ground by a piece of pipe, typically 100 mm PVC sewer gradepipe, attached to the tank by two durable plastic ropes. These ropes are anchored in the rim of thetank and have a loop in the other end at excavation ground level. Both pipes have a length of notless than the diameter of the tank and each is passed through two loops. Backfilling then covers thepipes.

10.4 Manufacture

10.4.1 Materials

10.4.1.1PolymerThe polymer utilised by the manufacturer shall be suitable so that the finished product meets theperformance requirements as set out in this Standard.

10.4.1.2FastenersAll fasteners shall be of durable material, resistant to the corrosive environment, and be either:

(a) Stainless steel, grade 316 (see AS 1449 or NZS/BS 1449); or

(b) Copper alloy, grade 443 (see AS 2738.2 or NZS/BS 1400); or

(c) a suitable equivalent

10.4.2 Manufacturing process

10.4.2.1GeneralThe manufacturing process shall be carried out in a controlled manner to produce a consistent productchecked by a quality assurance process.

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10.4.2.2JointsThe lid and the access opening cover shall be bedded on a bead of flexible mastic sealant in accordancewith the manufacturer’s instructions and then secured in a position with fasteners to provide a permanentwater-tight seal.

10.4.2.3FastenersFasteners shall be provided where required in the tank design to ensure joint seals are secure.

10.4.2.4Provision of fittings and their assembly

10.4.2.5Inlet and outlet fittings(a) Inlet and outlet fittings may either be installed by the manufacturer prior to delivery of the septic

tank, or be installed by the licensed plumber /drainlayer at the time of installation of the septic tank.

(b) When inlet and outlet fittings, access and inspection covers, partition, anchorage device, and anynecessary fasteners are provided separate to the tank for installation on-site detailed installationinstructions shall be provided by the manufacturer with each tank at the time of despatch.

10.4.2.6PartitionsThe permanent fixing of a partition into the septic tank shall be in accordance with the manufacturer’sinstructions and may be carried out on-site at the time of installation of the tank.

10.5 Testing Refer Section 5: Testing requirements of septic tanks.

10.5.1 Type testingType testing of completed septic tanks shall be carried out as required by Section 2 of this Standard againstrelevant appendices, (listed in Section 5, Clause 5.2.1). All septic tanks shall be capable of complying withthese type tests.

10.5.2 Routine quality control testing

10.5.2.1GeneralManufacturers shall establish tests on tank materials and/or finished tanks, and a frequency of testing thatwill demonstrate that a consistent quality of product is being produced.

The testing of the properties of the polyolefin tank material during/after manufacture is essentially aninternal quality function because the nature and thickness of materials used will vary from onemanufacturer to another.

10.5.2.2Test specimen(a) The test specimen shall reflect the manufacturing process;

(b) The test specimen shall reflect a typical cross section of the septic tank;

(c) The specimen shall be manufactured at the same time as the septic tank;

(d) The specimen may be cut from a vertical section of the tank wall using a low speed cutting tool toprevent heat damage or other damage to the specimen;

(e) The dimensions of the test specimen shall be appropriate for the required tests.

10.5.2.3TestsManufacturers shall set up tests to determine flexural modulus, and to determine resistance to impact, as aminimum.

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C10.5.2.3A modified ASTM impact test that has been found to be satisfactory with polyolefin samples taken from, ormade to represent, a septic tank wall is to be found in Appendix K.

10.5.2.4Frequency(a) The frequency of testing will be governed by the needs of any internal quality assurance programme,

or external quality assessment programme;

10.5.2.5Pass/failThe test results should meet the criteria set for the tests in this section of the Standard.

10.5.2.6Test recordsThe report shall include the following information for each test specimen:

(a) Identification of persons/organisation carrying out test;

(b) Identification of the sample tested;

(c) Date of test;

(d) The test results;

(e) Reference to the test method.

Test records shall be kept as required by the quality assurance programme.

(A minimum of ten years is recommended.)

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APPENDIX AREFERENCED DOCUMENTS(Normative)

STANDARDS

AUSTRALIA NEW ZEALAND

AS 1012 Methods of testing concreteAS 1012.8 Part 8: Method for making and curing concrete

compression, indirect tensile and flexure test specimens,in the laboratory or in the field

AS 1012.9 Part 9: Method for the determination of the compressivestrength of concrete specimens

AS 1012.14 Part 14: Method for securing and testing cores fromhardened concrete for compressive strength

NZS 3112:1986 Methods of test for concreteNZS 3112:Part 2 Tests relating to the determination of strength of concrete

AS 1302 Steel reinforcing bars for concreteNZS 3402:1989 Steel bars for the reinforcement of concrete

AS 1303 Steel reinforcing wire for concreteNZS 3421:1975 Specification for hard drawn mild steel wire for concrete

reinforcement

AS 1304 Welded wire reinforcing fabric for concreteNZS 3422:1975 Specification for welded fabric of drawn steel wire for

concrete reinforcement

AS 1379 The specification and manufacture of concreteNZS 3104:1991 Specification for concrete production - High grade and

special grade

AS 1449 Wrought alloy steels - Stainless and heat-resisting steelplate, sheet and strip

NZS/BS 1449 Steel plate,sheet and strip.NZS/BS 1449.2:1983 Part 2: Specification for stainless and/heat resisting steel

plate, sheet and strip

AS 1478 Chemical admixtures for concreteNZS 3113:1979 Specification for chemical admixtures for concrete

AS 1546 Small septic tanksNZS 4610:1982 Specification for household septic tank systems

AS 1597 Precast reinforced concrete box culvertsAS 1597.1 Small culverts (not exceeding 1200 mm width and

900 mm depth).

AS 2738 Copper and copper alloys - Compositions anddesignations

AS 2738.2 Part 2: Wrought products

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NZS/BS 1400:1985 Specification for copper alloy ingots and copper alloy andhigh conductivity copper castings

AS 2758 Aggregates and rock for engineering purposesAS 2758.1 Part 1: Concrete aggregates

NZS 3121:1986 Specification for water and aggregate for concrete

AS 3600 Concrete structuresNZS 3109:1987 Specification for concrete construction

AS 3972 Portland and blended cementsNZS 3122:1995 Specification for Portland and blended cements (General

and special purpose)

NZS 3106:1986 Code of practice for concrete structures for the storage ofliquids

JOINT AUSTRALIA/NEW ZEALAND

AS/NZS 1547 On-site domestic wastewater management (inpreparation)

AS/NZS 3500.2 Sanitary plumbing and drainageAS/NZS 3500.2.2 Part 2.2 Acceptable solutions

AMERICAN

ASTM C 1018:1994 Test method for flexural toughness and first-crackstrength of fiber-reinforced concrete (using beam withthird-point loading)

ASTM D 3029:1990 Test methods for impact resistance of flat, rigid plasticspecimens by means of a tup (falling weight)

PS 15:69 Custom contact-moulded reinforced-polyester chemicalresistant process equipment (U.S. Department ofCommerce)

BRITISH

BS 3396:1987 Woven glass fibre fabrics for plastics reinforcement

BS 3496:1989 Specification for E glass fibre chopped strand mat forreinforcement of polyester and other liquid laminatingsystems

BS 3691:1990 Specification for E glass fibre rovings for reinforcementof polyester and epoxy resin systems

BS 3749:1991 Specification for E glass fibre woven roving fabrics forthe reinforcement of polyester and epoxy resin systems

BS 4994:1987 Specification for design and construction of vessels andtanks in reinforced plastics

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INTERNATIONAL (ISO)

ISO 62: 1980 Plastics - Determination of water absorption

ISO 75-3: 1974 Plastics - Determination of temperature of deflectionunder load.Part 3 High strength thermosetting laminates and long-fibre- reinforced plastics

ISO 178:1993 Plastics - Determination of flexural properties

ISO 179:1993 Plastics - Determination of Charpy impact strength.

ISO 527:1993 Plastics - Determination of tensile propertiesPart 1: General principlesPart 2: Test conditions for moulding and extrusionplastics

ISO 1172:1996 Textile-glass-reinforced plastics - Prepregs, mouldingcompounds and laminates - Determination of the textileglass and mineral-filler content - Calcination methods

ISO 1268:1974 Plastics - Preparation of glass fibre reinforced, resinbonded, low-pressure laminated plates or panels for testpurposes

NOTE: AS/NZS denotes a jointly developed and published Australian/ New Zealand Standard.NZS/AS or NZS/BS denotes an Australian or British Standard approved and adopted for use inNew Zealand without technical change.

NEW ZEALAND LEGISLATION

Building Act 1991Building Regulations 1992Resource Management Act 1991New Zealand Building Code 1991

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APPENDIX BSEPTIC TANK CAPACITIES(Informative)

B1 ScopeThis appendix gives recommended minimum capacities for conventional septic tanks.

B2 Application and context of use

B2.1 ApplicationThe capacities are sufficient for normal domestic premises that are not fitted with water-conservingdevices or a garbage grinder. (Refer also Clause 2.4.1.)

B2.2 Context of useSeptic tanks of these capacities are already in use in parts of Australia and New Zealand but have not beenadopted as minimum sizes throughout. They are presented as a guide for authorities and manufacturers towork towards.

The capacities have been calculated using relevant flow data and other considerations in AS/NZS 1547 (incourse of preparation).

CB2.2AS/NZS 1547 (in course of preparation) should be consulted for the derivation of tank sizes for the non-standard situations not covered in Table B1.

B3 Conventional septic tanksThe minimum capacity of conventional septic tanks for treatment of domestic wastewater flow isrecommended to be as shown in Table B1:

TABLE B1 CONVENTIONAL SEPTIC TANK CAPACITIES (LITRES)

Type of wastewater Persons Bedrooms

1 to 5 6 to 10 1 to 3 4 to 6

All-waste

Greywater only

Blackwater only

L

3000

1800

1500

L

4500

2700

2500

L

3000

1800

1500

L

4500

2700

2500

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APPENDIX CTEST OF THE MANUFACTURER’S INSTRUCTIONS FOR THE INSTALLATION OFFITTINGS IN A SOUND AND WATERTIGHT MANNER(Normative)

C1 ScopeThis Appendix sets out a method for the type testing of the manufacturer’s instructions for the installationof fittings in a sound and watertight manner, whether the fittings are installed in the factory or on site.

C2 PrincipleThe fittings in a tank are subjected to a low hydrostatic pressure from inside the tank.

(It is assumed that a fitting installation that is watertight in this situation will also be watertight in respectof water ingress to the tank through the fittings.)

C3 Testing(a) A tank is set up for the watertightness test as required by Appendix E, Clause E4.1;

(b) Fittings are installed in accordance with the manufacturer’s instructions;

(c) Openings in the fittings are sealed to allow water to build up behind the fitting during the test;

(d) The tank shall be filled with water to the rim.

C4 Pass/FailThere shall be no leakage of water through the join of the fitting and tank, or through any joins in thefittings themselves.

C5 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Identification of the fitting systems(s) tested;

(c) Date of test;

(d) The results of the test;

(e) Reference to this test method, i.e. AS/NZS 1546, Appendix C.

Test records shall be kept as required by the quality assurance programme.

CC5A minimum of 10 years is recommended.

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APPENDIX DDETERMINATION OF THE RESISTANCE OF A PARTITION TO A HYDROSTATIC HEAD(PUMPOUT TEST)(Normative)

D1 ScopeThis Appendix sets out a method for type testing the resistance of a tank partition to the effects of pumpingout fluid from one side of the partition.

D2 PrincipleWith the removal of fluid from one side of a partitioned tank during pump-out, the partition may besubjected to a hydrostatic pressure head. This test reproduces those conditions and then checks for anysigns of weakness or failure of the partition.

D3 TestingThis test may be carried out in conjunction with the watertightness test, see Appendix E.

(a) A tank is set up for the watertightness test as required by Appendix E, Clause E4.1 (a) to (c);

(b) The tank is either filled with water as required by Appendix E, Clause E4.1(d), or to the top of thepartition or to the level of any hole through it;

(c) Water is pumped out from one side of the partition. If the partition is situated so that there is agreater quantity/head of water on one side as compared to the other then the water shall be pumpedout from the side that has the least quantity/head;

(d) Observe the reaction of the partition to the effects of the pumpout process, and if necessary over aperiod of at least 5 minutes.

D4 Pass/FailThe tank shall be able to be pumped out without the partition collapsing or permanently deforming.

D5 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Identification of the tank tested;

(c) Date of test;

(d) The results of the test;

(e) Reference to this test method, i.e. AS/NZS 1546, Appendix D.

Test records shall be kept as required by the quality assurance programme

CD5A minimum of 10 years is recommended.

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APPENDIX EDETERMINATION OF WATERTIGHTNESS(Normative)

E1 ScopeThis Appendix sets out a method of testing of the watertightness of septic tanks. The test is used as a typetest and as a quality control test when required

E2 PrincipleThe tank is subjected to a hydrostatic pressure head and is then examined for signs of water leakage.

E3 ApparatusAt least three bearing blocks are required: 500 mm (minimum) length x 100 mm wide x 100 mm deep;

E4 Testing

E4.1 ProcedureThe procedure shall be as follows:

(a) Tanks that can be stood in position without the need of support shall be placed on the bearer blocks,(see Figure E1(a));

(b) Tanks that need support in order to remain in position e.g. horizontal cylinders shall be placed ontimber bearers and held in place with chocks, (see Figure E1(b)). Horizontal cylindrical tanks shallbe supported sufficiently so as to counter any bending and induced tension;

(c) Tanks shall be levelled on the supports;

(d) The tank shall be filled with water to a depth of 900 mm or to the invert of the outlet pipe, whicheveris the greater depth;

(e) Allow to stand for a minimum of 4 hours;

(f) Top up with water and start test observations;

(g) Observe for any leakage and count the drops per minute from any single point.

CE4.1(g)Damp patches in concrete tanks are not considered leakage.

E4.2 Test criteria(i) Concrete septic tanks shall not show a leakage rate greater than 4 drops/min;

(ii) Glass fibre-reinforced or plastic tanks shall have no leakage, and no damp patches;

E4.3 FrequencyThe frequency of testing will be governed by the needs of any internal quality assurance programme, orexternal quality assessment programme.

CE4.3When used as a quality control test it is recommended that at least one septic tank per week be tested.This should be representative of the capacity and design of tank made in that week. When a number ofdifferent capacity or design tanks are made in a manufacturing period then each capacity or designshould be tested on a rotation basis of a minimum rate of one per week.

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E5 Pass/failShould the leakage rate be exceeded or there is visible cracking, the septic tank shall be rejected.

E6 RepairIsolated minor leakages in concrete tanks may be repaired so as to effectively and permanently seal theleak. After repair, the tank must be retested.

E7 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Identification of the tank tested;

(c) Date of test;

(d) The leakage rate, in drops per minute;

(e) Reference to this test method, i.e. AS/NZS 1546, Appendix E.

Test records shall be kept as required by the quality assurance programme.

CE7A minimum of ten years is recommended.

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Dimensions in millimetres

FIGURE E1 WATERTIGHTNESS TEST ARRANGEMENT FOR HORIZONTAL ANDVERTICAL TANK(Diagrammatic only)

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APPENDIX FDETERMINATION OF RESISTANCE TO LATERAL LOAD - HYDRAULIC TEST METHOD(Normative)

F1 ScopeThis appendix sets out a method for testing the resistance of a septic tank to an applied lateral load. Analternative test (based on point load testing) is given in Appendix G.

F2 PrincipleThe lateral (side loading) forces on a septic tank due to soil in a fully or partially saturated state, togetherwith any accidental (incidental) additional loading due to the presence of earth moving equipmentadjacent to the tank wall may be represented by a circumferential load applied to the wall of the septictank.

These forces equate approximately to the forces applied to an empty tank held submerged in water.

The test method requires that compression forces due to any anchorage technique normally used with theseptic tank are simulated during the test.

F3 Apparatus This test is carried out using:

(a) A container large enough to allow the test tank to fit within and for the tank to be submerged inwater;

(b) Weights or hydraulic ram assembly used to reproduce any compression induced in a tank by themechanism of anchorage, if any;

(c) The test tank complete with lid.

F4 Procedure(a) The container base shall be levelled;

CF4(a)This may be achieved on a sand bed of sufficient area. The top and bottom surfaces of the sand bedshould be level and the sand should be not less than 100 mm deep.

(b) The empty test tank shall be installed and restrained as necessary in the container. If it is necessaryto reproduce anchorage compression, weights shall be placed on the upper rim of the tank cylinder;

The holding down of the tank shall be such as to not provide any lateral stability to the tank in excessof that of that provided by the lid, when installed.

(c) The outer container shall be filled with water up to the outlet level of the test tank. The watertemperature shall not exceed 230C.

F5 AssessmentInspection shall show that there have been no leaks and that the integrity of the tank has not sufferedpermanent damage. See Clause 2.4.10.

F6 Frequency The testing shall be carried out as per the requirement of any internal quality assurance programme orexternal quality assessment programme.

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F7 RetestingShould a tank fail the lateral load test a further two tanks shall be selected from the same batch as thetank that failed. These tanks shall be tested as above. If the two additional tanks meet the loadrequirements the batch shall be deemed to meet the test requirements. If one of the additional tanks failsthe batch shall be rejected or every tank subjected to the lateral load test.

CF7Should a prototype tank fail, a new design and testing programme will be required.

F8 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Identification of the tank tested;

(c) Date of test;

(d) The presence and size of any cracking, and any other defects noted;

(e) Reference to this test method, i.e. AS/NZS 1546, Appendix F.

Test records shall be kept as required by the quality assurance programme.

CF8A minimum of ten years is recommended.

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APPENDIX GDETERMINATION OF RESISTANCE TO LATERAL LOAD - POINT LOAD TEST METHOD(Normative)

G1 ScopeThis appendix sets out two methods for testing the resistance of a septic tank to an applied lateral pointload. An alternative test is given in Appendix F.

G2 PrincipleThe lateral (side loading) forces on a septic tank due to soil in a fully or partially saturated state, togetherwith any accidental (incidental) additional loading due to the presence of earth moving equipmentadjacent to the tank wall may be represented by a point load applied to the wall of the septic tank.

The lateral load is applied to the tank by the application of thrust on the side wall of the tank through abearing block using a controlled and measured force. Different loads are applied depending on whether theseptic tank is tested empty or full of water.

The test method requires that compression forces due to any anchorage technique normally used with theseptic tank are present during the test.

G3 ApparatusThis test is carried out by using:

(a) A bearing block 250 x 250 x 100 mm shaped to match the external shape of the tank to be tested;

(b) A rubber pad, 13 mm thick to fit the bearing block, of Shore durometer hardness 45-55;

(c) A hydraulic ram to which the bearing block is fixed;

(d) A pressure gauge from which the pressure recorded can be used to calculate the total force applied;

(e) A frame to hold the hydraulic ram, gauge and pad assembly at the required position depending onthe geometry of the tank;

CG3(e)Such a frame is described in AS 1597.1 (Appendix B, figure B1). This frame is also used for the topload test described in Appendix H of this Standard.

(f) Circumferential or line support shall be provided;

(i) Circumferential support. Circular/curved septic tanks shall be supported by a length notgreater than one quarter of the external perimeter centrally located opposite the applied lateralpoint load. The support shall be provided for the full height of vertical tanks or full length ofhorizontal tanks. For non-circular tanks the support shall be provided to the side opposite theapplied lateral load.

(ii) Line support shall be provided for the full height of vertical tanks or full length of horizontaltanks directly opposite the applied lateral point load.

(g) A sand bed positioned beneath the test frame of sufficient area to accommodate the test tank. The topand bottom surfaces of the sand bed shall be level and the sand shall be not less than 100 mm deep;

CG3(g)This sand bed is also used for the top load test described in Appendix H of this Standard.

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(h) Weights or hydraulic ram assembly used to reproduce any compression induced in a tank by themechanism of anchorage, if any;

(i) Crack measuring gauge;

(j) Test tank complete with lid.

G4 Procedure

G4.1 Testing of tank filled with waterTanks may be tested in a vertical or horizontal position.

(a) Assemble test tank on the bed of sand beneath the test frame complete with circumferential or linesupport and, if needed, anchorage compression;

(b) Apply a lateral point load one third of tank height from the base, or at the spring line for horizontalcircular tanks;

(c) Apply a lateral point load of

(i) 25 kN if circumferential support is provided, or

(ii) 12.5 kN if line support is provided;

d) The load shall be increased uniformly so that the specified value is reached in 5 minutes. The loadshall be applied via the bearing block and rubber pad.

G4.2 Testing of empty septic tankTesting shall be as described in Clause G4.1 with load applied to be 17 kN if circumferential support isprovided or 8.5 kN if line support is provided.

G5 AssessmentIf cracks occur they shall be checked by means of the test crack measuring gauge. The load shall than bereleased and the surface again examined to check whether all test cracks have closed.

The tank shall be free of fractures and cracks wider than 0.15 mm and residual cracks wider than 0.1 mm(approximately) and from other defects arising from faulty materials or faulty methods of manufacture.

The dimensions of the test cracks shall be determined in accordance with AS 1597 Part 1, Section 3Clause 3.2.1.

G6 FrequencyThe testing shall be carried out as per the requirement of any internal quality assurance programme orexternal quality assessment programme.

G7 RetestingShould a tank fail the load tests a further two tanks shall be selected from the same batch as the tank thatfailed. These tanks shall be tested as above. If the two additional tanks meet the load requirements thebatch shall be deemed to meet the test requirements. If one of the additional tanks fails the batch shall berejected or every tank subjected to the lateral load test.

CG7Should a prototype tank fail the load tests, a new design and retesting will be required.

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G8 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Identification of the tank tested;

(c) Date of test;

(d) The presence and size of any cracking, and any other defects noted;

(e) Reference to this test method, i.e. AS/NZS 1546, Appendix G.

Test records shall be kept as required by the quality assurance programme.

CG8A minimum of ten years is recommended.

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APPENDIX HDETERMINATION OF RESISTANCE TO TOP LOADING(Normative)

H1 ScopeThis appendix sets out a method for testing the resistance of a septic tank to an applied top load.

H2 PrincipleA vertical downward top load is applied to the tank lid and access opening cover. The test method is basedon that given in AS 1597.1, Section 3, and allows for both proof and ultimate load testing.

H3 Apparatus(a) A frame and winch assembly that straddles a sand bed, (see Figure H1), being an adaption of the test

rig in AS 1597.1;

(b) A bearing block - 250 x 250 x 100 mm;

(c) A rubber pad, 13 mm thick to fit bearing block, of Shore durometer hardness 45-55;

(d) A proof test load of 5 kN (approx. 510kg);

(e) Crack measuring gauges.

H4 Procedure

H4.1 GeneralThree vertical tanks or three horizontal tanks complete with lids and access opening covers, shall be testedin accordance with AS 1597.1, ‘Load test requirements’, with a proof load of not less than 5 kN as shownin Figure H1.

H4.2 Load applicationThe load shall be increased uniformly so that the specified value is reached in 5 minutes. The load shall beapplied via the bearing block and rubber pad.

H5 AssessmentIf cracks occur they shall be checked by means of the test crack measuring gauge. The load shall than bereleased and the surface again examined to check whether all test cracks have closed.

The tank, lid and access opening cover shall be free of fractures and cracks wider than 0.15 mm andresidual cracks wider than 0.1 mm (approximately) and from other defects arising from faulty materials orfaulty methods of manufacture.

The dimensions of the test cracks shall be determined in accordance with AS 1597 Part 1, Section 3Clause 3.2.1.

H6 FrequencyThe testing shall be carried out as per the requirement of any internal quality assurance programme orexternal quality assessment programme.

H7 RetestingShould a tank fail the load tests a further two tanks shall be selected from the same batch as the tank thatfailed. These tanks shall be tested as above. If the two additional tanks meet the load requirements thebatch shall be deemed to meet the test requirements. If one of the additional tanks fails the batch shall berejected or every tank subjected to the top load test.

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CH7Should a prototype tank fail the load tests, a new design and retesting will be required.

H8 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Identification of the tank tested;

(c) Date of test;

(d) The presence and size of any cracking, and any other defects noted;

(e) Reference to this test method, i.e. AS/NZS 1546, Appendix H.

Test records shall be kept as required by the quality assurance programme.

CH8A minimum of ten years is recommended.

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(a) Typical vertical septic tank with lid and access opening cover in place

(b) Typical horizontal septic tank with access opening cover in place

FIGURE H1 TYPICAL LOAD TESTING SET-UP(Diagrammatic only)

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APPENDIX IINSTALLATION OF SEPTIC TANKS(Informative)

I1 ScopeThis section gives guidance for the on-site installation of septic tanks.

I1.1 Siting of tanks

AustraliaThe siting of tanks is subject to regulatory authority approval and may require the submission of a certifiedengineering design to allow construction close to buildings and in trafficable areas.

New ZealandThe siting of tanks may be subject to regulatory authority approval and may require the submission of acertified engineering design to allow construction close to buildings and in trafficable areas.

GeneralIn general, tanks should be installed clear of any buildings so as not to affect any structural elements ofbuildings.

CI1.1As a guide tanks should be installed sufficiently clear of buildings to provide an angle of repose of at least45o between the bottom of the footing and the base of the tank.

NOTE: The possible escape of highly explosive gases from septic tanks must receive consideration inthe installation design.

I1.2 SoilTanks should be installed in stable soil conditions. Where there is doubt the installer should give fulldetails and specifications on how it is intended to provide a sound foundation for the tank.

I1.3 Surface WaterSurface waters should be diverted from the tank installation. Special measures need to be taken in case of ahigh ground water table or flood prone areas.

I1.4 Location on SiteThe location of septic tanks on sites is subject to approval by the regulatory authority. In any case, thereshall be compliance with building clearances and block/section boundaries as provided for in by-laws andRegulations.

I1.5 DrainageThe drainage system shall comply with AS/NZS 3500.2 or the NZ Building Code. All drainage levelsshould be considered to ensure appropriate gradients leading into the tank and to allow gravity dischargeof effluent to the top of the disposal area, (where appropriate).

I1.6 DesludgingThe tank(s) should be sited with due consideration for future de-sludging operations and the siting of theeffluent treatment system. Where access for desludging by vehicle is not available the application forapproval of the installation must state the manner in which it is intended to desludge the tank at thenecessary intervals without creating a health nuisance.

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I2 Installation instructions

I2.1 GeneralManufacturers should ensure that installation instructions are supplied that are relevant to the materialfrom which the tank is constructed.

I2.2 CouncilsIt is recommended that regulatory authorities require that installation instructions are provided with thebuilding permit/consent application.

I2.3 ManufacturerFor each installation the manufacturer should supply written instructions which are specific to theirproduct and the materials used. The instructions should allow installation in a safe and workmanlikemanner.

The instructions should cover, but be not necessarily restricted to, the following information:

(a) Special provisions concerning excavation relevant to the tank type or special provisions if theinstallation is freestanding;

(b) The preparation of the bottom of the excavation;

(c) The method of safe handling and lifting;

(d) Special instructions where the installation could be subject to ground water or floatation;

(e) Fitting of any components inlets, outlets, partitions, square junctions and gas baffles;

(f) Backfilling - recommendation of choice of material and the method of backfilling to beadopted;

(g) Need to fill tank with water during backfilling operations;

(h) Methods of sealing and re-sealing tank lids and access/inspection covers/openings andassociated extensions;

(i) Commissioning instructions.

I2.4 RepairsAny repairs should be done so that the tank meets the requirements of this Standard.

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APPENDIX JDETERMINATION OF THE HARDNESS OF GLASS FIBRE-REINFORCED PLASTICCOMPOSITES(Normative)

J1 ScopeThis Appendix sets out a method for determining the hardness of reinforced plastic laminates for septictanks.

J2 PrincipleThe Barcol hardness test gives a measure of the degree of cure of the glass fibre-reinforced composite.

J3 ApparatusA Barcol Impressor Model GYZJ-934-1* , or equivalent.

J4 Test specimensThe hardness test may be carried out directly on the tank or on test specimens prepared in accordance withISO 1268. The test specimens shall have been manufactured for not less than 48 hours, be substantiallyflat, have a smooth surface and be at least 2.5 mm thick.

J5 ProcedureThe Barcol Impressor shall be applied to the surface and pressed firmly, and the dial gauge readingsimultaneously noted. Not less than 20 readings shall be taken on the laminate of each tank or specimen inrandom fashion over the surface being tested.

The top three and bottom three readings shall discarded and the remaining 14 shall be averaged.

J6 FrequencyThe testing shall be carried out as per the requirement of any internal quality assurance programme orexternal quality assessment programme.

J7 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Identification of the tank tested;

(c) Date of test;

(d) The average Barcol hardness number;

(e) References to this test method, i.e. AS/NZS 1546, Appendix J.

Test records shall be kept as required by the quality assurance programme.

CJ7A minimum of ten years is recommended.

* Made by the Barber Colman Co., Rockford, Illinois, U.S.A.

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APPENDIX KDETERMINATION OF THE IMPACT RESISTANCE OF MOULDED POLYOLEFIN SEPTICTANKS(Informative)

K1 ScopeThis Appendix sets out a method of determining the impact resistance of polyolefin septic tanks. It appliesto tanks made in any manner using thermoplastic polyolefin resins

The test is essentially an internal quality control test that will ensure that a constant moulding is beingmade. Results are dependent on the thickness of the material being tested.

K2 PrincipleMethod F of ASTM D 3029: 1990 allows the mean energy to cause specimen failure to be calculated aftera dart-shaped weight is allowed to fall vertically on to the test specimen.

K3 ApparatusThe following apparatus is required. It should, unless otherwise detailed, conform with Method F ofASTM D3029:1990. It is comprised essentially of:

(a) A supporting frame mounted on a rigid base fitted with levelling screws, and capable of allowing asteel dart to fall freely and centrally from a height of 100 mm;

(b) A clamping frame to carry the test panel, mounted on the base of the supporting frame in such aposition that the steel dart will fall centrally into the clamping frame. The test panel supportclamping plate has a hole of 20 mm diameter placed centrally beneath the dart;

(c) A steel dart of configuration of Figure 3B of ASTM D 3029 and manufactured as per Standard;

(d) A steel dart support capable of supporting a 13.5 kg weight, complete with release mechanism;

(e) Weights, cylindrical, which will fit onto the shaft of the steel dart.

K4 Procedure(a) The test specimens shall be cut from a test panel prepared in accordance with Clause 10.4.1;

(b) The test specimen shall be clean;

(c) Visually examine the surface of the test specimen using the x 10 eyepiece for any sign of cracks;

(d) The test specimen shall be fitted and secured into a clamping frame;

(e) The steel dart is allowed to drop onto the test specimen from a height of 100 mm. The dart shall beloaded with weights to that amount which is expected to cause half the specimens to fail;

(f) Failure is defined as the presence of a crack or split created by the impact of the falling steel dart,that can be seen under normal laboratory lighting conditions.

K5 FrequencyThe testing shall be carried out as per the requirement of any internal quality assurance programme orexternal quality assessment programme.

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K6 Test recordsThe report shall include the following information for each test specimen:

(a) Identification of person/organisation carrying out test;

(b) Method of preparation of test specimens and as necessary the identification of any tank tested;

(c) Weights required to cause failure;

(d) Types of failure eg crack or cracks on one surface only, cracks that penetrate the thickness, brittleshatter, ductile failure, other observed deformation;

(e) Date of test;

(f) References to this test method, i.e. AS/NZS 1546, Appendix K.

Test records shall be kept as required by the quality assurance programme.

CK6A minimum of ten years is recommended.

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