Readers are advised to check the validity of this Certificate by either referring to the BBA’s website (www.bbacerts.co.uk) or contactingthe BBA direct (Telephone Hotline 01923 665400).

Klargester Environmental LtdCollege RoadAston ClintonAylesburyBucks HP22 5EWTel: 01296 633000 Fax: 01296 633001

AgrémentCertificate

No 86/1700Fourth issue*

Designated by Governmentto issue

European TechnicalApprovals

KLARGESTER EFFLUENT TREATMENT PRODUCTSSystèmes de traitement des aux résiduairesAbwasseraufbereitung

Product Regulations and Legislation — Detail Sheet 1

• THIS CERTIFICATE RELATESTO KLARGESTER EFFLUENTTREATMENT PRODUCTS.• Each product is for thetreatment or collection of eitherdomestic sewage or surfacewater.• The products are for use inconjunction with domesticdrains and public and privatesewers for the collection andtreatment of surface waterand/or domestic sewage as ispermitted to be discharged intopublic sewers by the WaterIndustry Act 1991, theSewerage (Scotland) Act 1968and the Water and SewageServices (Northern Ireland)Order 1973.• This Certificate does notcover the use of any of theproducts for untreated tradeeffluents.

This Front Sheet must be readin conjunction with theaccompanying Detail Sheets,which provide information tospecific products.

1 The Building Regulations 2000 (as amended) (England and Wales)The Secretary of State has agreed with the British Board of Agrémentthe aspects of performance to be used by the BBA in assessing thecompliance of effluent treatment systems with the Building Regulations.

In the opinion of the BBA, Klargester Effluent Treatment Products, if used inaccordance with the provisions of this Certificate, will meet or contribute tomeeting the relevant requirements.Requirement: H2 Wastewater treatment systems and cesspools

Comment: See the marked sections of the Design Data part of theaccompanying Detail Sheets.

Requirement: Regulation 7 Materials and workmanship

Comment: The products are acceptable.

2 The Building Standards (Scotland) Regulations 1990 (as amended)In the opinion of the BBA, the position of Klargester Effluent TreatmentProducts, if used in accordance with the provisions of this Certificate,will satisfy or contribute to satisfying the various Regulations and

related Technical Standards as listed below.Regulation: 10 Fitness of materials and workmanshipStandards: B2.1 and B2.2 Selection and use of materials, fittings, and components, and workmanship

Comment: The products are acceptable.Regulation: 24 DrainageStandard: M3.1 Private wastewater treatment systems — Private wastewater treatment plant or

septic tanks

The septic tanks and BioDisc can meet the relevant requirementsof this Technical Standard. See the marked sections of theDesign Data part of the accompanying Detail Sheets.Cesspools are not permitted under these Regulations.

3 The Building Regulations (Northern Ireland) 2000In the opinion of the BBA, Klargester Effluent Treatment Products, if usedin accordance with the provisions of this Certificate, will satisfy orcontribute to satisfying the various Building Regulations as listed below.

Regulation: B2 Fitness of materials and workmanship

Comment: The products are acceptable.Regulation: N6 Cesspools, septic tanks and similar structures

Comment: The products can meet the relevant requirements of thisRegulation. See the marked sections of the Design Data partof the accompanying Detail Sheets.

CI/SfB

(5.3)

4 The Health and Safety at Work etc Act 1974 and the Health and Safety atWork (Northern Ireland) Order 1978In buildings subject to this Act and Order, regular maintenance is arequirement for the Klargester BioDisc. See the section on Cleaning in therespective Detail Sheet.

5 Construction (Design and Management) Regulations 1994 (as amended) Construction (Design and Management) Regulations (Northern Ireland)1995 (as amended)

Information in this Certificate may assist the client, planning supervisor,designer and contractors to address their obligations under these Regulations.See sections: 2 Delivery and site handling (2.1), and Installation (General)

of the appropriate Detail Sheets.

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Conditions of Certification

6 Conditions6.1 This Certificate:(a) relates only to the product that is described,installed, used and maintained as set out in thisCertificate;(b) is granted only to the company, firm or personidentified on the front cover — no other company,firm or person may hold or claim any entitlement tothis Certificate;(c) has to be read, considered and used as awhole document — it may be misleading and willbe incomplete to be selective;(d) is copyright of the BBA.

6.2 References in this Certificate to any Act ofParliament, Regulation made thereunder, Directiveor Regulation of the European Union, StatutoryInstrument, Code of Practice, British Standard,manufacturers’ instructions or similar publication,shall be construed as references to such publicationin the form in which it was current at the date ofthis Certificate.

6.3 This Certificate will remain valid for anunlimited period provided that the product and themanufacture and/or fabricating process(es) thereof:(a) are maintained at or above the levels whichhave been assessed and found to be satisfactoryby the BBA;

(b) continue to be checked by the BBA or itsagents; and(c) are reviewed by the BBA as and when itconsiders appropriate.

6.4 In granting this Certificate, the BBA makes norepresentation as to:(a) the presence or absence of any patent orsimilar rights subsisting in the product or any otherproduct;(b) the right of the Certificate holder to market,supply, install or maintain the product; and(c) the nature of individual installations of theproduct, including methods and workmanship.

6.5 Any recommendations relating to the use orinstallation of this product which are contained orreferred to in this Certificate are the minimumstandards required to be met when the product isused. They do not purport in any way to restate therequirements of the Health & Safety at Work etcAct 1974, or of any other statutory, common lawor other duty which may exist at the date of thisCertificate or in the future; nor is conformity withsuch recommendations to be taken as satisfying therequirements of the 1974 Act or of any present orfuture statutory, common law or other duty of care.In granting this Certificate, the BBA does notaccept responsibility to any person or body for anyloss or damage, including personal injury, arisingas a direct or indirect result of the installation anduse of this product.

British Board of AgrémentP O Box No 195, Bucknalls LaneGarston, Watford, Herts WD25 9BAFax: 01923 665301

©2002For additional information about theCertificate, tel: 01923 665300.For information about AgrémentCertificate validity and scope,tel: Hotline 01923 665400, orcheck the BBA website.

e-mail: mail@bba.star.co.ukwebsite: www.bbacerts.co.uk

In the opinion of the British Board of Agrément, Klargester Effluent Treatment Products are fit fortheir intended use provided they are installed, used and maintained as set out in this Certificate.Certificate No 86/1700 is accordingly awarded to Klargester Environmental Ltd.

On behalf of the British Board of Agrément

Date of Fourth issue: 12th December 2002 Chief Executive

*Original Certificate issued on 4th August 1986. This amended version issued to include a change to the Certificateholder’s name, reference to the updated Building Regulations, the addition of CDM Regulations and new Conditions ofCertification.

Electronic Copy

Readers are advised to check the validity of this Detail Sheet by either referring to the BBA’s website (www.bbacerts.co.uk) or contactingthe BBA direct (Telephone Hotline 01923 665400).

• THIS DETAIL SHEET REPLACES DETAIL SHEET 5AND RELATES TO THE KLARGESTER BIODISC, ASELF-CONTAINED SEWAGE TREATMENT PLANTIN TWO SIZES SUITABLE FOR POPULATIONSBETWEEN 1 AND 12.• The product is manufactured and marketed byKlargester Environmental Ltd. It is also marketed byKlargester Ireland in Newry, Co Down.• The product is for use in sewage treatmentsystems designed in accordance with therecommendations of BS 6297 : 1983, for theretention of domestic sewage, separation andcollection of solids, biological treatment of settledsewage and settlement of humus solids insuspension prior to discharge of the treated effluent.

This Detail Sheet must be read in conjunction with theFront Sheet, which gives the product’s position regardingthe Building Regulations, and the Conditions ofCertification.

Technical Specification

1 Description1.1 The Klargester BioDisc (see Figure 1) has theform of a circular tank with tapering or verticalsidewalls blending into a cylindrical base. The unitsare constructed from glass-reinforced polyester(GRP) made of chopped strand glass fibreslaminated in a polyester resin system. The tank isinternally divided with a partition wall separatingthe primary and secondary settlement zones (seeFigure 1). Suspended above within the primarysettlement zone is a GRP Biozone, which includesa semi-cylindrical chamber in which the RotatingBiological Contactor (RBC) is housed and rotates.The RBC consists of a hollow rolled galvanizedsteel section shaft with welded stub ends. Agalvanized steel section framework is built onto theshaft and supports the polypropylene ‘media’ (seeFigure 1). The shaft and steelwork are zinc metal,

Certificate No 86/1700

DETAIL SHEET 6Second issue*

Klargester Environmental Ltd

KLARGESTER BIODISC

Product

CI/SfB

(90.51) Xn8

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sprayed or galvanized to protect against corrosion.The shaft is supported on self-aligning plasticbearings and rotated slowly by a motor andgearbox using reinforced rubber belt and pulleys.The Biozone is assembled and supported within themain GRP case. The RBC is divided using bafflesattached to the ‘media packs’ or fixed into theBiozone. The BioDisc and all internal mechanicaland electrical systems are protected by a GRPcover.

Figure 1 Klargester BioDisc

1.2 The inlet and outlet sockets 110 mm are ofPVC-U and Kitemarked to BS EN 1401-1 : 1998.Each socket incorporates a captive rubber ring toBS EN 681-1 : 1996 Type WC. The sockets aredesigned to accept PVC-U pipe spigots butconnection to other systems (eg vitrified clayware toBS 65 : 1991 and BS EN 295-1 : 1991) can bemade by means of a short length of PVC-U pipe, toBS EN 1401-1 : 1998, and appropriateadaptors.

1.3 Crude sewage passes through the inlet intothe primary settlement zone, where the breakdownand storage of solids takes place. The heavierparticles sink and settle to form primary sludge andthe lighter particles remain in suspension or form ascum on the surface. Both the sludge and scum willbegin to break down under the action of bacteriaand other organisms. The partly clarified sewagepasses through a submerged baffle into the firstcompartment of the Biozone. The primary sludgeand scum are drawn off by a suction tanker atregular intervals (see Table 1).

1.4 The RBC ‘media’ support a biologically activefilm known as biomass, which is alternatelyexposed to sewage liquor and air by the rotationof the RBC, which is partially immersed in thesewage liquor. The liquor passes through theBiozone after passing through the primarysettlement zone. A managed flow system betweenthe first stage rotor and the second stage rotorcontrols and balances the forward feed (seeFigure 1). Excess biological growth falling off the‘media’ in the initial part of the Biozone can passthrough the slot at the bottom into the primarysettlement zone. In the remaining stages of theBiozone, the excess biological growth is kept insuspension by the turbulence created by therotation of the RBC. The sewage liquor passingthrough the Biozone is progressively biologicallyoxidised, reducing the organic material content.The resulting purified sewage passes into the finalsettlement zone, where the excess biological growth(humus solids) either settles or forms floating scum.Sludge from the secondary settlement zone is drawnoff at the same intervals as the primary sludge (seeTable 1). A facility to return the humus sludge to theprimary tank can be provided as an optional extrato the system. If this option is incorporated, sludgeremoval from the primary tank only will suffice.Scum removal from both primary and finalsettlement tanks will need to be carried out.

Table 1 BA and BB BioDisc — basic information

Unit size BA BB

Population equivalent 6 (single household) 12 (2 households)Media area (m2) 72.5 97.5Diameter (mm) 1995 1995

shallow standard deep shallow standard deepInlet invert depth 450 750 1250 450 750 1250(mm)

Outlet invert depth 520 820 1320 520 820 1320(mm)

Height to rim ofcover (mm) 1945 2245 2745 1945 2245 2745

Overall height 2160 2460 2960 2160 2460 2960(mm)

Empty weight 0.31 0.325 0.38 0.335 0.35 0.405(tonnes)

Desludge period(approx) 12 months 6 months

Desludge volume (m3) 2.65 2.65Drive rating 1 phase/3 phase (kW) 0.06 0.06

Approx daily power consumption (kWh/day) 1.6 1.9

1.5 The main tank is manufactured by sprayingfrom cold-setting polyester resin reinforced withglass fibres. The cover, Biozone and the baffles aremade in a similar way. The RBC ‘media’ is vacuumformed from polypropylene copolymer sheets.

primarysettlementtank

second stagerotor

first stagerotor

finalsettlementtank

outletinlet

biozone

managedflow

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1.6 The motor, gearbox, sprockets and bearingsare fixed to the steel framework by stainless,galvanized or sherardized steel bolts.

1.7 Quality control includes laminate thicknesschecks on the GRP components, plating thicknessof zinc on galvanized components and thechecking of bought-in components againstspecification. Each completed unit is checked andtest-run to ensure it is mechanically sound.

2 Delivery and site handling2.1 BA and BB BioDiscs must be lifted usingwebbing slings of a suitable specification whichmust be attached to the designated lifting points.Lifting equipment should be selected by taking intoaccount the unit weight, dimensions and thedistance of lift required on site.

2.2 The product bears the marketing company’sname, labels denoting the inlet and outlet, a list ofall the items supplied, installation guidance, theproduct specification code, serial numbers andinspection date.

Design Data

3 General

3.1 The Klargester BioDisc models BA andBB are suitable for the collection andtreatment of domestic sewage from one or

two households, respectively, where the maximumnumber of persons resident does not exceed six(BA) and twelve (BB), provided the sewage outputper person does not exceed 200 litres and60 grammes of Biochemical Oxygen Demandper day. The units are not suitable for nitrification.

3.2 Units are available with differing inlet invertdepths to accommodate site drain levels (seeTable 1).

3.3 The general design of the installation must bein accordance with BS 6297 : 1983.

3.4 The BA and BB BioDiscs should be sited asfar as possible from domestic dwellings, inaccordance with the relevant Building Regulations.

3.5 Groundwater and flood levels should alwaysbe below plant outlet level, unless specificarrangements have been made to overcome thisproblem.

3.6 Where discharge is required to be at a higherlevel, an internal pumped outlet option is available.This item has not been covered by the scope of thisassessment.

3.7 The discharge from the unit must be to asuitable sub-soil irrigation system or watercourse inaccordance with the requirements of theEnvironment Agency, the Scottish EnvironmentProtection Agency or the Environment and HeritageService, Belfast.

3.8 The treated effluent discharging from theBioDisc will normally be within Band 1 of Table 10of BS 7781 : 1994 [ie suspended solids (SS)content <30 mg per litre and Biochemical OxygenDemand (BOD5) <20 mg per litre], provided thehydraulic and BOD loadings are within themanufacturer’s specifications (see section 3.1).Under certain conditions the effluent may not bewithin these Standards. This is normal for anybiological sewage treatment process and can becaused by unusual hydraulic or BOD loading,weather conditions, contamination by grease,excessive amounts and/or strength of laundrywastewater, or poisoning of the microbiologicalfauna and flora by chemicals or antibiotics.

3.9 Pre-fabricated sample chambers (as shown onthe front page of this Detail Sheet) are available tocomply with the discharge consent requirements ofthe Environment Agency. These items are outsidethe scope of this assessment.

3.10 The dimensions and other particulars of theBA and BB are as shown in Table 1.

3.11 The units can be fitted with a warningdevice which will activate an alarm if the RBC stoprotating for any reason, other than a mains supplyfailure.

3.12 Klargester Environmental Ltd offer theirBioDisc clients a maintenance service contract forregular inspection and necessary maintenance ofBioDisc units. They also undertake repair work.

3.13 The specification and power requirements ofthe BioDisc range are listed in Table 1.

3.14 The BioDisc can be used to providetemporary sewage treatment facilities. A shortperiod of acclimatisation must be allowed aftercommissioning of the unit before a full degree oftreatment can be expected. This period is generallya few weeks and is normal for any biologicaltreatment plant.

4 Strength4.1 The manufacturer’s design has been assessedas satisfactory. BA and BB BioDiscs have adequatestrength to resist damage from minor impacts duringhandling. They must be slung at the lifting pointsprovided (see section 2.1).

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4.2 BA and BB BioDiscs must be installed inaccordance with the Installation Guidelinesprovided with the units (see section 10 forinstallation summary). Particular attention should begiven to the provision of concrete backfill to resistflotation due to groundwater.

5 Resistance to chemicalsThe BioDisc is resistant to the small quantities ofacid, alkali or other substances likely to be found innormal domestic sewage or the surroundingbackfill.

6 Watertightness

The BioDisc, when correctly installed, will notallow seepage either into or from thesurrounding soil. The pipe joints, when

correctly made, will be watertight.

7 Cleaning and maintenance7.1 Cleaning and maintenance should be carriedout in accordance with the Owner’s Handbooksupplied with each unit. A copy of the DesludgeInstructions is also fastened to the inside of eachunit. When carrying out any work on a BioDisc it isimportant to observe all the Health and Safetywarnings in the Owner’s Handbook.

Summary of main desludging instructions

7.2 Isolate power to the unit and remove thecover to allow access for desludging.

7.3 Desludging is effected by a suction tanker,taking care to avoid damage by the hose nozzle.Both the primary and secondary settlement tanksmust be desludged as detailed in the Owner’sHandbook and Desludge Instructions. All coversand guards must be replaced before reconnectionof the power supply. The control panel should beleft locked shut.

7.4 Monthly inspection by the user isrecommended, involving a visual inspection andremoval of any debris.

7.5 Local damage to GRP components can berepaired by the manufacturer or a suitablyexperienced person using standard GRP repairtechniques. Repairs must be carried out in dryconditions and the GRP laminate to be repairedmust be thoroughly cleaned, dried, lightly abradedand prepared with a suitable bonding agent.

7.6 Rust spots on steelwork should be wirebrushed and coated with a zinc-based paint.

Flooding7.7 Repair or replacement may be requiredshould the mechanical and electrical componentsbe subject to damage in the event of flooding.

Frequency of inspection7.8 Where the system is installed and used insituations subject to The Health and Safety at Worketc Act 1974 and The Health and Safety at Work(Northern Ireland) Order 1978, an inspection ofthe system must be carried out every six months.

8 DurabilityThe structural properties of the GRP from which thetank is constructed, in common with all similarmaterials, will deteriorate with time. Thedeterioration is accelerated by contact withgroundwater, sewage and dissolved or suspendedorganic or inorganic compounds (the resulting lossof strength and stiffness has been taken intoaccount in the manufacturer’s design code). TheGRP components should remain serviceable for atleast 20 years. Protected steel components mayrequire further protection by painting. Themechanical and electrical components are liable towear during operation, but the design layout issuch that they can be replaced as required.

Installation

9 General9.1 Klargester Environmental Ltd can advise clientsof the installation requirements. A national networkof certified installers exists, who can offer a fullinstallation service.

9.2 Electrical connections to the BioDisc unit fromthe control box must be carried out by a competentperson using material suitable for the purpose.

9.3 Electrical connections must be in strictaccordance with the manufacturer’s instructions andmust comply with the local electricity distributionauthority’s regulations. Cables must be protectedfrom accidental damage by a suitable conduit orother means of protection. The electrical controlpanel and housing must be sited adjacent to theunit, but not so close that the panel and the BioDiscunit can be touched simultaneously. The panel mustalso be sited to protect it from accidental damageby vehicles or weather conditions.

9.4 The BioDisc must not be installed in areasliable to localised flooding without adequateprotection as specified by the marketing company.

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9.5 It is essential to take precautions to preventdamage by site traffic. Superimposed loads fromvehicles, etc should not be permitted within adistance equal to the depth of excavation, unlesssuitable structural protection is provided. A fencemay be required to prevent vehicles fromapproaching too close to the unit.

Siting9.6 BioDisc units should be sited so that:• they are not prejudicial to the health of any

person

• there is an adequate means of access foremptying, ie within 30 m of a vehicle access,without the contents being taken through adwelling or place of work.

10 Procedure10.1 BioDisc units are installed buried so that therim of the cover is approximately 95 mm aboveground level. The excavation must be large enoughfor easy placement of the unit, to permit subsequentbackfilling and to allow timbering and sheeting asrequired to meet Regulation 8(1) of theConstruction (General Provision) Regulations 1961(see Figure 2)

10.2 The units are bedded onto concrete which ishaunched up around the base of the unit. Theconcrete must be of sufficient thickness (minimum150 mm) to ensure that the unit is adequatelysupported with due regard to sub-soil conditionsand the loads imposed by the BioDisc when full.Care must be taken to eliminate all voids. The topflange must be level to within ± 5 mm.

10.3 In dry, freely draining ground the unit can bebackfilled with gravel. In all other circumstances theunit should be backfilled with a minimum thicknessof 150 mm of concrete.

10.4 The backfill should be carefully consolidatedaround the unit, to ensure even transfer of loadsand prevent localised stress concentrations. The unitshould be ballasted with water, keeping the waterlevel just above the backfill level as workprogresses.

10.5 The tank is connected to 110 mm PVC-Usockets at the inlet and outlet. For other types ofpipe, such as vitrified clayware, etc, suitableadaptors are used with short lengths of PVC-U pipeas necessary. A short length of pipe with flexiblejoints at both ends should be used adjacent to theBioDisc to allow for differential movement betweenthe BioDisc unit and adjacent pipe runs.

10.6 The control panel is erected by setting thegalvanized sheet leg in a concrete base. Seesections 9.2 and 9.3, regarding electricalconnections.

Figure 2 Installation of BioDisc

SPECIALISTS

O

IN LWATE PR OL UTI N CONTR OLSPECIALISTS

O

IN LWATE PR OL UTI N CONTR OL

Klargester

SPECI

N

ALISTS IN W

O

A

P

TER

LLUTION CO TROL

SPECI

N

ALISTS IN W

O

A

P

TER

LLUTION CO TROL

Klargester

shallow unit shown

GL

concrete orgranular fill(eg pea shingle)

concrete150 mm thick

concrete 150 mm thick andhaunched up 150 mm all round

dry site wet site

granularbackfill(eg pea shingle)

control panel

outlet

inlet

power supplyfrom house

inlet cable to control panel

5

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Technical Investigations

The following is a summary of the technicalinvestigations carried out on the Klargester BioDisc.

11 Tests11.1 Tests were carried out in accordance withMOAT No 9 : 1973 to determine:resin/glass ratio, based on BS 2782-10 :

Method 1002 : 1977barcol hardness, based on BS 4549-1 : 1970cross-breaking strength by water boil, based on

methods in BS 3532 : 1990, Appendix C andBS 2782-3 : Method 335A 1978

degree of cure, by the Coggeshall testwater soak test, based on ISO 62 : 1980.

11.2 The durability of the GRP on prolongedexposure to water was assessed by exposingsamples to boiling water for 1000 hours andmeasuring the loss of cross-breaking strength,bending stiffness and ductility.

12 Investigations12.1 An assessment was made of the structuralcalculations and assumptions made in the design ofthe BioDisc components manufactured by theCertificate holder.

12.2 An examination was made of the results ofsample analyses of effluent from BioDisc units,carried out to measure BOD and suspended solidscontent.

12.3 Components were assessed for:GRP propertieswatertightnessdegradation of properties from exposure to

sewage, ground water, dissolved salts and diluteacids or alkalis

long-term loading conditionsstructural steel components specification and

durability of the corrosion protection process.suitability for use of bought-in items.

12.4 The manufacturing process was examined,including the methods adopted for quality control,and details were obtained of the quality andcomposition of the materials used.

12.5 Visits were made to sites to assess thepracticability and ease of installation.

12.6 A survey was undertaken of existing sites,where the product had been installed, to assess itsperformance in use.

6

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7

On behalf of the British Board of Agrément

Date of Second issue: 12th December 2002 Chief Executive

*Original Certificate issued on 17th June 1998. This amended version issued to include a change to the Certificateholder’s name, updated British Standards and a revised Bibliography.

Bibliography

BS 65 : 1988 Specification for vitrified clay pipes,fittings, joints and ducts

BS 2782-3 : Method 335A : 1978 Methods oftesting plastics — Mechanical properties —Determination of flexural properties of rigid plasticsBS 2782-10 : Method 1002 : 1977 Methods oftesting plastics — Glass reinforced plastics —Determination of loss on ignition

BS 3532 : 1990 Method for specifyingunsaturated polyester resin systems

BS 4549-1 : 1970 Guide to quality controlrequirements for reinforced plastics mouldings —Polyester resin mouldings reinforced with choppedstrand mat or randomly deposited glass fibres

BS 6297 : 1983 Code of practice for design andinstallation of small sewage treatment works andcesspools

BS 7781 : 1994 Procedure for type testing ofsmall biological domestic wastewater treatmentplants

BS EN 295-1 : 1991 Vitrified clay pipes andfittings and pipe joints for drains and sewers —Requirements

BS EN 681-1 : 1996 Elastomeric seals —Material requirements for pipe joint seals used inwater and drainage applications — Vulcanizedrubber

BS EN 1401-1 : 1998 Plastics piping systems fornon-pressure underground drainage and sewerage.Unplasticized poly(vinylchloride) (PVC-U) —Specifications for pipes, fittings and the system

ISO 62 : 1980 Plastics — Determination of waterabsorption

MOAT No 9 : 1973 Directive for the Assessmentof Products in Glass-Reinforced Polyester for use inBuilding

Electronic Copy

British Board of AgrémentP O Box No 195, Bucknalls LaneGarston, Watford, Herts WD25 9BAFax: 01923 665301

©2002For additional information about theCertificate, tel: 01923 665300.For information about AgrémentCertificate validity and scope,tel: Hotline 01923 665400, orcheck the BBA website.

e-mail: mail@bba.star.co.ukwebsite: www.bbacerts.co.uk

Electronic Copy

Readers are advised to check the validity of this Detail Sheet by either referring to the BBA’s website (www.bbacerts.co.uk) or contactingthe BBA direct (Telephone Hotline 01923 665400).

Technical Specification

1 Description1.1 The Klargester Press Moulded Septic Tank(see Figure 1) is made from a glass-fibre reinforcedpolyester (GRP) compound and is press moulded inthree parts. The tank is generally spherical in shapewith a flattened base and shoulders. The pressedstub neck is glued and bolted to the tank top. Asprayed laminated glass-fibre neck is glued to thestub neck and allows access for emptying. The tankis available in three capacities and with two inverts,ie suitable for installation at depths to a maximuminvert of 1.0 m and 1.5 m. The dimensions andweights of the units are given in Table 1.

Figure 1 Klargester Press Moulded Septic Tank

Table 1 Tank dimensions and weights

Capacity Diameter Internal Distance from Finished weightdiameter of invert level of includingaccess shaft inlet pipe to accessories

tank base (kg)(I) (mm) (mm) (mm) (1.0 m invert)

2800 1905 460 1565 105

3800 2070 460 1795 154

4600 2080 460 2035 169

1.2 Internally, the tank is divided into threecompartments using slotted, high-densitypolyethylene cones. Incoming sewage enters thefirst compartment from a sewer via a roddable dippipe; large solids settle within this compartment.Separated settled effluent rises into the second andthird stages in sequence via a dedicated flowroute. The breakdown of solids in suspension andpartial digestion of suspended organic materialoccurs at each stage. The physical separation ofthe compartments and the dedicated flow routeoptimizes solid liquid separation.

1.3 The 110 mm PVC-U inlet and outlet socketsare Kitemarked to BS EN 1401-1 : 1998. Eachsocket incorporates a captive rubber ring toBS EN 681-1 : 1996, Type WC. The sockets aredesigned to accept PVC-U pipe spigots. Connectionto other systems, such as clayware to BS 65 :1991 is by means of a short length of PVC-U pipeto BS EN 1401-1 : 1998 and appropriateadapters.

1.4 Pedestrian-duty pressed steel covers andmoulded frames are manufactured to suit theaccess shaft.

inlet

outlet

separationzones

settlementchamber

• THIS DETAIL SHEET RELATES TO THE KLARGESTER PRESS MOULDEDSEPTIC TANK, A COMPOSITE PRESS MOULDED GLASS-FIBREREINFORCED POLYESTER SEPTIC TANK, AVAILABLE IN THREE SIZESWITH TWO INVERTS AND WITH A PEDESTRIAN-DUTY COVER ANDFRAME, SUITABLE FOR POPULATIONS BETWEEN 1 AND 14.• The product is for use in sewage treatment systems designed inaccordance with the recommendations of BS 6297: 1983 for thecollection of domestic sewage and for separation and partial digestion ofsuspended matter.• The product is manufactured by Klargester Environmental Ltd. It is alsoassembled and marketed by Klargester Ireland in Newry, Co Down.This Detail Sheet must be read in conjunction with the Front Sheet and DetailSheet 1, which give the product's position regarding the Building Regulations andthe Conditions of Certification.

Certificate No 86/1700

DETAIL SHEET 7Second issue*

Klargester Environmental Ltd

KLARGESTER PRESS MOULDEDSEPTIC TANK

Product

CI/SfB

(52.3) Xn8

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1.5 Quality control tests includes visual andthickness checks. Components are weighed andtanks are tested to working pressure.

2 Delivery and site handling2.1 The tank is supplied with lifting shackles fittedto the stub neck. The tank should be lifted with ropeor webbing slings when handled by mechanicalmeans. Care is necessary to avoid damage orpenetration of the tank by sharp objects.

2.2 The tank is marked with the marketingcompany’s name, type, capacity, invert and theBBA identification mark incorporating the numberof this Certificate.

Design Data

3 General3.1 The Klargester Press Moulded Septic Tank issuitable for the collection and partial treatment ofdomestic sewage. The unit is designed and shouldbe installed in accordance with therecommendations of BS 6297 : 1983.

3.2 The tank must be installed at a minimumdistance of 7 m from habitable buildings.

3.3 Ventilation must be provided to ensure thatventilation of noxious and inflammable gases canoccur.

3.4 The maximum population that may be servedby each size of tank is given in Table 2.

Table 2 Tank size selection

Capacity No of No of persons if the whole of the(I) persons population served have waste disposal units(1)

2800 1–4 1–33800 5–9 4–74600 10–14 8–10

(1) If only part of the population uses waste disposal units, then acalculation should be carried out in accordance with BS 6297 : 1983.

3.5 Effluent from the tank requires further treatmentbefore final discharge if this is to a ditch orwatercourse. This further treatment should besufficient to ensure that the suspended solids contentis less than 30 mgl–1 and the Biochemical OxygenDemand (BOD) is less than 20 mgl–1 (ie Band 1 ofTable 10 of BS 7781 : 1994) or to suchstandards as are required by the EnvironmentAgency concerned.

3.6 Alternative methods of disposal, such assubsoil irrigation or disposal on land, may be used,but the local Environment Agency must beconsulted.

3.7 Unless suitably designed protection in the formof a reinforced concrete surround, including anappropriate cover, is provided, the tank should bemarked or fenced off to prevent superimposedloading by vehicles etc, in an area within thefollowing radii given in Table 3.

Table 3 Radius of fenced off area

Tank Radius of fenced off area to be Capacity not less than the invert depth plus

the following dimensions(I) (m)

2800 2.13800 2.44600 2.6

4 Strength4.1 The manufacturer’s design has been assessedas satisfactory. The tank has adequate resistance towithstand minor impacts during handling but caremust be taken to avoid dropping or striking the tankagainst hard, sharp objects.

4.2 The cover and frame assembly is suitable foruse where subject to foot traffic only.

5 Resistance to chemicals The tank is resistant to the small quantities of acid,alkali or other substances to which it may normallybe exposed through contact with domestic sewage.

6 WatertightnessThe tank, when correctly installed, will not allowseepage either into or from the surrounding soil. Thepipe joints, when correctly made, will be watertight.

7 Cleaning and maintenance7.1 The tank must be de-sludged at least once ayear.

7.2 The tank is easily de-sludged, in theconventional manner, by a suction tanker. Liquid isdrawn from the centre of the tank, which allowsaccess to all the compartments. All grease solidsshould be removed. Care must be taken to avoiddamage by the hose nozzle.

8 Safety A suitable cover should be used where there is arisk of the cover being removed by children orunauthorized persons, to reduce the risk of seriousor fatal accidents. The cover should be lockable; orprovide reduced diameter access.

9 Durability The structural properties of the composite GRP, fromwhich the tank is constructed, in common with allother similar materials, will deteriorate with time.This deterioration is accelerated by contact withgroundwater, sewage, and dissolved or suspendedorganic or inorganic compounds. The resulting lossof strength and stiffness has been taken intoaccount in the manufacturer's design code. In theopinion of the BBA, the product, when used in thecontext of this Certificate, will have a life in excessof 30 years, when installed in accordance with thisCertificate.

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Installation

10 General 10.1 Klargester Press Moulded Septic Tankinstallation must be strictly in accordance with themarketing company’s instructions, Klargester SepticTank Installation Procedure PD 213. The tank mustbe installed according to the ground conditions andthe appropriate method selected (see Figure 2).10.2 A wet site is one where the subsoil is of apoor draining nature, eg clay, and or wheregroundwater may lie above the base of the tank atany time.

11 Procedure11.1 The excavation must be of sufficient size topermit easy placing of the tank and subsequentbackfilling of the tank, and to allow timbering andsheeting as required. The excavation depth must beas specified by the manufacturer for the size of tankbeing installed.11.2 A bed of medium workability concretebetween 150 mm and 300 mm thick dependingon site conditions must cover the bottom of theexcavation. In wet sites, the bottom of theexcavation should be covered with 150 mm ofconsolidated hard core and the entire excavationlined with polythene sheeting prior to laying theconcrete bed.11.3 The tank must be placed truly vertical ontothe levelled foundation, the tank inlet connectionlined up with the incoming drain, and backfillingcompleted in stages up to invert depth.

11.4 In dry ground the backfill material must begraded shingle or selected non-cohesive material,free from large stones, bricks or sharp objects.Where there is a possibility of a high water tableor where the tank is installed in non-free draining orheavy clay soils (ie wet site conditions), the tankshould be surrounded with concrete not less than150 mm thick.11.5 The backfill must be carefully consolidatedaround the tank, to ensure even transfer of soil loadto the tank shell and to prevent localized stressconcentrations. Concrete surround must be carefullyplaced and compacted around the tank and thetank simultaneously filled with water to the risinglevel of the concrete. The surround should bebrought up to a level 50 mm below the outlet pipe.11.6 Connections are made to the tank using110 mm diameter PVC-U pipes or to othersuitable pipes, using a short length of 110 mmdiameter PVC-U pipe and adapters as necessary.A short length of pipe with flexible joints must beused adjacent to the tank to allow for differentialmovement. A ventilating pipe should be fitted tothe tank neck as shown in Figure 1.11.7 Backfilling can then be continued to groundlevel and the neck cut off with a fine-toothed sawto a suitable height to enable an appropriate coverand frame to be installed.11.8 The cover frame must be bedded on concrete.11.9 The tank must not be installed at a depthgreater than the invert provided with the tank.11.10 It is essential to take precautions to preventdamage by site traffic.

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Figure 2 Installation instructions

backfill to suit dry soilconditions (pea shingle)

shingle under pipe

rodding and vent access

frame to be beddedon concrete and benchedover flange as shown

concrete bed haunchup around base

backfill to suit wet soilconditions (concrete)

ensure septic tank outletheight is set 25 mmbelow inlet

shingle under pipe

blank off tee if not fittinga vertical riser

suitable fill/soil

concrete backfill aroundneck (wet soil conditions)

Dry well drained site Wet poorly drained site

inletoutlet

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Technical Investigations

The following is a summary of the technicalinvestigations carried out on the Klargester PressMoulded Septic Tank.

12 Tests12.1 The tests listed below were carried out todetermine:resin/glass ratio, based on ISO 1172 : 1975barcol hardness, based on BS 4549-1 : 1970cross breaking strength by water boil, based on

methods in BS 3532: 1990Appendix C and BS 2782-3 : Method 335A : 1993degree of cure, by the Coggeshall testwater soak test, based on ISO 62 : 1980watertightness.

12.2 The durability of the GRP on prolongedexposure to water was assessed by exposingsamples to boiling water for 1000 hours and thenmeasuring any loss in cross-breaking strength,bending stiffness or ductility.12.3 Vacuum testing of complete tanks was carriedout to check the validity of the manufacturer'sdesign, with respect to buckling and fracture of thetank, when subjected to external pressure.

13 Investigations13.1 A re-examination was made of the data onwhich the previous Certificates were based. Theconclusions drawn from the original data remainvalid.13.2 An assessment was made of the structuralcalculations and assumptions made in the designof the tank.13.3 Assessments were made of the tank inrelation to:water tightnessdegradation of mechanical properties owing to

exposure to sewage, groundwater, dissolvedsalts and dilute acids or alkalis

long-term loading conditions.

13.4 The manufacturing process was examined,including the methods adopted for quality controland details were obtained of the quality andcomposition of the materials used.

Bibliography

BS 65 : 1991 Specification for vitrified clay pipes,fittings and ducts, also flexible mechanical joints foruse solely with surface water pipes and fittingsBS 2782-3 : Method 335A : 1993 Methods oftesting plastics — Mechanical properties — Plastics— Determination of flexural propertiesBS 3532 : 1990 Method for specifyingunsaturated polyester resin systemsBS 4549-1 : 1970 Guide to quality controlrequirements for reinforced plastics mouldings —Polyester resin mouldings reinforced with choppedstrand mat or randomly deposited glass fibresBS 6297 : 1983 Code of practice for design andinstallation of small sewage treatment works andcesspoolsBS 7781 : 1994 Procedure for type testing of smallbiological domestic wastewater treatment plantsBS EN 681-1 : 1996 Elastomeric seals — Materialrequirements for pipe joint seals used in water anddrainage applications — Vulcanized rubberBS EN 1401-1 : 1998 Plastics piping systems fornon-pressure underground drainage and sewerage.Unplasticized poly(vinylchloride) (PVC-U) —Specifications for pipes, fittings and the systemISO 62 : 1980 Plastics — Determination of waterabsorptionISO 1172 : 1975 Textile glass reinforced plastics— Determination of loss on ignition

British Board of AgrémentP O Box No 195, Bucknalls LaneGarston, Watford, Herts WD25 9BAFax: 01923 665301

©2002For additional information about theCertificate, tel: 01923 665300.For information about AgrémentCertificate validity and scope,tel: Hotline 01923 665400, orcheck the BBA website.

e-mail: mail@bba.star.co.ukwebsite: www.bbacerts.co.uk

On behalf of the British Board of Agrément

Date of Second issue: 12th December 2002 Chief Executive

*Original Detail Sheet issued on 26th June 2000. This amended version issued to include a change to the Certificateholder’s name and revised Bibliography.

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Readers are advised to check the validity of this Detail Sheet by either referring to the BBA’s website (www.bbacerts.co.uk) or contactingthe BBA direct (Telephone Hotline 01923 665400).

Technical Specification

1 Description1.1 The Klargester Septic Tank (Figure 1) is madefrom glass-fibre reinforced polyester laminate and isof spherical shape with a flattened base and acylindrical access shaft. The tank is available in threecapacities and two grades (see Tables 1 and 2).

Table 1 Grade selection (all capacities)

Maximum invert depth of inlet pipe (m) Grade

1.0 standard1.5 heavy

1.2 Internally, the tank is divided into threecompartments by glass-fibre reinforced polyesterlaminate (other sizes). Incoming sewage enters

• THIS DETAIL SHEET REPLACES DETAIL SHEET 2 AND RELATES TO THEKLARGESTER SEPTIC TANK, A GLASS-FIBRE REINFORCED POLYESTERSEPTIC TANK, AVAILABLE IN THREE SIZES AND TWO GRADES ANDWITH A LOCKABLE PEDESTRIAN-DUTY PRESSED STEEL COVER ANDFRAME.• The products are for use, in sewage treatment systems designed inaccordance with the recommendations of BS 6297 : 1983, for thecollection of domestic sewage and for separation and partial digestion ofsuspended matter.• The tanks are for use in locations where the number of people served isas indicated in Table 3.• The products are manufactured by Klargester Environmental Ltd. They arealso marketed by Klargester Ireland in Newry, Co Down.

This Detail Sheet must be read in conjunction with the Front Sheet and DetailSheet 1, which give Conditions of Certification and the product’s positionregarding the Building Regulations, respectively.

Certificate No 86/1700

DETAIL SHEET 8Klargester Environmental Ltd

KLARGESTER SEPTIC TANK

Product

CI/SfB

(52.3)

Figure 1 The Klargester Septic Tank

‘A’

overall diameter

‘B’ 15 mm�

invert(to suit)

600

ground level

inlet inverter + 25 mm(outlet inverter)

100 mm PVC-U outlet (swivelling)

ball shown in seating

Klargester pedestrian dutycover and framefresh air inlet (customer supply)

100 mm PVC-Uinlet (swivelling)

backfill to suit dry soil conditions(pea-shingle or other suitablefree-flowing material) backfill to suit wet soil

conditions (concrete)

concrete bed

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the first compartment from a sewer via a roddabledip pipe. It then passes through submerged slotsinto the second and third stages, with breakdownof gross solids, separation and partial digestionof suspended organic material occurring at eachstage.

1.3 The 110 mm PVC-U inlet and outlet socketsare Kitemarked to BS EN 1401-1 : 1998. Eachsocket incorporates a captive rubber ring toBS EN 681-1 : 1996, Type WC. The socketsare designed to accept PVC-U pipe spigots.Connection to other systems, such as clayware toBS 65 : 1991 and BS EN 295-1 : 1991, is bymeans of a short length of PVC-U pipe, toBS EN 1401-1 : 1998, and appropriate adaptors.

1.4 Lockable pedestrian-duty covers and framesare available to suit the 600 mm diameter accessshaft.

1.5 The product is manufactured to thedimensions and weights given in Table 2. Thetank (which is constructed in upper and lowerhalves) is manufactured by spray/hand lay-upfrom cold-setting polyester resin and choppedglass-fibre rovings and woven rovings.

Table 2 Tank dimensions and weights

Capacity Diameter Internal Distance from Finished weight‘A’ diameter invert level including

of access of inlet pipe accessoriesshaft to tank base

(litres) (mm) (mm) ‘B’ (mm) (kg)

Standard Heavy6000 2300 600 2400 235 2607500 2385 600 2585 285 3109000 2660 600 2660 330 365

1.6 Quality control includes visual and thicknesschecks and weighing the vessel; all tanks arevacuum tested to working pressure.

2 Delivery and site handling2.1 The tanks must be handled with rope orwebbing slings when lifted by mechanical means.Care is necessary to avoid damage orpenetration of the tank by sharp objects.

2.2 The tanks are marked with the marketingcompany’s name, grade, inlet and outletconnections and the BBA identification markincorporating the number of this Certificate.

Design Data

3 General3.1 Klargester Septic Tanks are suitable forthe collection and partial treatment ofdomestic sewage.

3.2 Usage requirement is to BS 6297 : 1983.Attention should be paid in locating the site to:

avoid superimposed loads from vehicles, etcwhere the septic tank is not adequatelyprotected (see section 3.6)

provide adequate venting arrangementsensure the site is not prejudicial to the health of

any personensure there will be no contamination to any

underground water or water supplyensure adequate means of access for emptying,

ie within 30 m of a hard standing suitable for adesludge vehicle

access without the contents being taken through adwelling or place of work.

3.3 Ventilation must be provided to ensureventing of noxious and inflammable gases.

3.4 The maximum population that may be servedby each size of tank is given in Table 3.

3.5 Effluent from any of the tanks requires furthertreatment before final discharge if this is to a ditchor watercourse. Alternative methods of disposalsuch as subsoil irrigation or disposal on land maybe used, but in every case the EnvironmentAgency must be consulted.

3.6 Unless suitably designed protection in theform of a reinforced concrete surround, includingan appropriate cover, is provided, the tank usedshould be marked or fenced off to preventsuperimposed loading by vehicles, etc in an areawithin the radii given in Table 4. This requirementdoes not apply in situations where the installationis inaccessible to motor vehicles.

Table 3 Tank size selection

Capacity No of persons No of personsif the total population

(litres) served have waste disposal units(1)

6000 15–22 11–167500 23–29 17–229000 30–39 23–28

(1) If part only of the population uses waste disposal units, a calculation shouldbe carried out in accordance with BS 6297 : 1983.

Table 4 Protection area

Tank capacity Radius of fenced-off area to benot less than the invert depthplus the following dimensions

(litres) (m)6000 2.87500 3.09000 3.2

4 Strength4.1 The manufacturer’s design has beenassessed and found to be satisfactory.

4.2 The tanks have adequate resistance towithstand minor impacts during handling but caremust be taken to avoid dropping or striking thetanks against hard, sharp objects.

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5 Resistance to chemicalsThe tanks are resistant to the small quantities ofacid, alkali or other substances to which they maynormally be exposed through contact withdomestic sewage.

6 WatertightnessThe tanks, when correctly installed, will notallow seepage either into or from thesurrounding soil. The pipe joints, when

correctly made, will be watertight.

7 Cleaning and maintenance7.1 The tanks must be desludged at leastonce a year.

7.2 The tanks are desludged easily by a suctiontanker. Care must be taken to prevent damage bythe hose nozzle.

7.3 Local damage to a tank may be repairable,depending on severity and position on the tank.The Certificate holder should be consulted beforeany action is taken.

8 SafetyAccess covers and frames provided for thetanks are not covered by the scope of thisCertificate. They must be of durable quality,

provide protection against entry, and have thenecessary strength for use in the location in whichthe tank is situated.

9 DurabilityThe structural properties of the GRP from whichthe tanks are constructed, in common withall other similar materials, will deteriorate

with time. The deterioration is accelerated bycontact with groundwater, sewage, anddissolved or suspended organic or inorganiccompounds. The resulting loss of strength andstiffness has been taken into account in themanufacturer’s design code. In the opinion of theBBA, the products, when used in the context of,and installed in accordance with, this Certificate,will have a life in excess of 30 years.

Installation

10 General10.1 Installation must be strictly in accordancewith the marketing company’s instructionsKlargester Septic Tank Installation Procedure.

10.2 The tanks must be positioned using liftinggear and suitably-rated webbing strips attachedto lifting eyes.

11 MethodDry ground conditions — installation11.1 A dry site is defined as one where thewater table is always below the bottom of thetank and the subsoil is well drained.

11.2 An excavation is made a minimum300 mm wider and 150 mm deeper than thetank. Additional allowance is made for anyshuttering required.

11.3 A bed of concrete a minimum 150 mmthick is laid.

11.4 The tank is lowered onto the concrete bed(see section 10.2) and the inlet and outlet pipeconnections are aligned to the incoming andoutlet drains.

11.5 When the tank is upright it is ballasted withwater to a depth of 500 mm, filling through theinlet pipe connection only. The concrete bed ishaunched up around the base to a depth of atleast 450 mm, it must be ensured that all voids inthe concrete are eliminated and that a minimum150 mm of concrete remains below the tankbase.

11.6 The excavation is backfilled evenly aroundthe tank to invert depth with pea-shingle or similarnon-cohesive and non-compressible free flowingmaterial; large or sharp stones, clay or materialswhich may form voids should be avoided. Sandmust not be used. The water level inside the tankmust be maintained to no more than 250 mm to500 mm above the backfill level.

11.7 All pipework is aligned and connectedensuring that the outlet pipe is a minimum 25 mmbelow the inlet pipe.

11.8 Care must be taken to avoid distortion ofthe tank neck when backfilling this area. Atemporary support brace can be used inside theneck or a Klargester frame is available (KlargesterCover and Frame assemblies are available forseparate purchase).

11.9 The tank neck is trimmed to ground levelusing a fine-toothed saw. For frost protection ofpipes, 450 mm is the minimum invert depth toground level. The tank neck should not betrimmed to a height lower than 350 mm abovethe inlet invert height.

11.10 The cover frame is bedded in concreteand the cover fitted. If the area is subject to trafficloads, section 3.6 should be referred to.

11.11 The tank should be left filled with water,this will be displaced as sewage enters.

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Wet ground conditions — installation11.12 A wet site is defined as one wheregroundwater lies above the base of the tank atany time or where there are slow draining claysoils.

11.13 An excavation is made to an appropriatedepth allowing 300 mm for a concrete and hardcore base. A minimum 400 mm must be allowedin excess of the tank width and any additionalallowance made for shuttering required. Watershould be pumped out of the excavation usingsuitable equipment and must not be discharged tosaturate the ground in the immediate vicinity.

11.14 A minimum 150 mm of hard core is laidover the base of the hole and the excavationlined with polythene sheeting.

11.15 A bed of concrete a minimum 150 mmthick is laid on top of the polythene.

11.16 The tank is lowered onto the concretebed (see section 10.2) and the inlet and outletpipe connections are aligned to the incoming andoutlet drains.

11.17 When the tank is upright it is ballastedwith water to a depth of 500 mm, filling throughthe inlet pipe connections only. The concrete bedis haunched up around the base to a depth of atleast 450 mm, it must be ensured that all voids inthe concrete are eliminated and that a minimumof 150 mm of concrete remains below the tankbase.

11.18 The excavation is backfilled evenlyaround the tank with concrete to invert depth,consolidating in layers. Backfilling should startbefore the base has hardened and be acontinuous operation encasing the tank in a singlejacket without joins. The water level inside thetank must be maintained to no more than250 mm to 300 mm above the concrete backfilllevel.

11.19 The concrete must not be dischargeddirectly on to the tank and vibrating pokers mustnot be used to consolidate the concrete.

11.20 All pipework is aligned and connectedensuring that the outlet pipe is a minimum 25 mmbelow the inlet pipe.

11.21 Care must be taken to avoid distortion ofthe tank neck when concreting this area. Atemporary support brace can be used inside theneck or a Klargester frame is available (KlargesterCover and Frame assemblies are available forseparate purchase).

11.22 A shell of concrete, 150 mm to 200 mmthick, must be built up around the neck of the tankbefore the backfill is completed using suitablematerial, eg pea-shingle or similar non-cohesiveand non-compressible free-flowing material.

11.23 The tank neck is trimmed to ground levelusing a fine-toothed saw. For frost protection ofpipes, 450 mm is the minimum invert depth toground level. The tank neck should not betrimmed to a height lower than 350 mm abovethe inlet invert height.

11.24 The cover frame is bedded in concreteand the cover fitted. If the area is subject to trafficloads, section 3.6 should be referred to.

11.25 The tank should be left filled with water,this will be displaced as sewage enters.

Material specification11.26 All references to concrete are for20 Nmm2 20 mm aggregate of 25 mm slumpmix in accordance with BS EN 206-1 : 2000.

11.27 Pea-shingle size 6 mm to 10 mm offeringlow point loading characteristics has been foundmost suitable for backfilling GRP tanks.

11.28 Polythene Sheet Building Quality500 gauge is recommended.

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Technical Investigations

The following is a summary of the technicalinvestigations carried out on the Klargester SepticTank.

12 Tests12.1 The tests listed below were carried out todetermine:(1) Resin/glass ratio, based on ISO 1172 :1975.(2) Barcol hardness, based on BS 4549-1 :1970.

(3) Cross-breaking strength by water boil, basedon methods in BS 3532 : 1990, Appendix Cand BS 2782 : Method 304B : 1970.

(4) Degree of cure, by the Coggeshall test.

(5) Water soak test, based on ISO 62 : 1980.

(6) The durability of the GRP on prolongedexposure to water was assessed by exposingsamples to boiling water for 1000 hours and thenmeasuring any loss in cross-breaking strength,bending stiffness or ductility.

(7) Watertightness.

(8) Strength of cover and frame assemblies.

12.2 Vacuum testing of complete tanks wascarried out to check the validity of themanufacturer’s design, with respect to bucklingand fracture of the tank, when subjected toexternal pressure.

12.3 Particle separation tests were carried out tocheck the performance of the baffle arrangements.

13 Investigations13.1 A re-examination was made of the data onwhich the previous Certificates were based. Theconclusions drawn from the original data remainvalid.

13.2 An assessment was made of the structuralcalculations and assumptions made in the designof the tank.

13.3 An examination was made of the results ofsample analyses of settled sewage from septictanks to measure suspended solids content andBiochemical Oxygen Demand.

13.4 A reassessment was made of the tank inrelation to:watertightnessdegradation of mechanical properties owing to

exposure to sewage, groundwater, dissolvedsalts and dilute acids or alkalis

long-term loading conditions.

13.5 Regular factory inspections have beencarried out to ensure that quality is beingmaintained.

13.6 A user survey and visits to established siteswere conducted to evaluate performance in use.

13.7 No failures of the product in use havebeen reported to the BBA.

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Bibliography

BS 65 : 1991 Specification for vitrified claypipes, fittings and ducts, also flexible mechanicaljoints for use solely with surface water pipes andfittings

BS 2782-3 : Method 304B : 1970 Methods oftesting plastics — Determination of flexuralproperties of rigid plastics

BS 3532 : 1990 Method for specifyingunsaturated polyester resin systems

BS 4549-1 : 1970 Guide to quality controlrequirements for reinforced plastics mouldings —Polyester resin mouldings reinforced with choppedstrand mat or randomly deposited glass fibres

BS 6297 : 1983 Code of practice for the designand installation of small sewage treatment worksand cesspools

BS EN 206-1 : 2000 Concrete — Part 1 :Specification, performance, production andconformity

BS EN 295-1 : 1991 Vitrified clay pipes andfittings and pipe joints for drains and sewers —Requirements

BS EN 681-1 : 1996 Vulcanized rubber

BS EN 1401-1 : 1998 Plastics piping systems fornon-pressure underground drainage and sewerage.Unplasticized poly(vinylchloride) (PVC-U) —Specifications for pipes, fittings and the system

ISO 62 : 1980 Plastics — Determination ofwater absorption

ISO 1172 : 1975 Textile glass reinforcedplastics — Determination of loss on ignition

6

On behalf of the British Board of Agrément

Date of issue: 12th December 2002 Chief Executive

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7

BLANK PAGE

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British Board of AgrémentP O Box No 195, Bucknalls LaneGarston, Watford, Herts WD25 9BAFax: 01923 665301

©2002For additional information about theCertificate, tel: 01923 665300.For information about AgrémentCertificate validity and scope,tel: Hotline 01923 665400, orcheck the BBA website.

e-mail: mail@bba.star.co.ukwebsite: www.bbacerts.co.uk

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Readers are advised to check the validity of this Detail Sheet by either referring to the BBA’s website (www.bbacerts.co.uk) or contactingthe BBA direct (Telephone Hotline 01923 665400).

Technical Specification

1 Description1.1 Klargester Cesspools are GRP, rib-stiffenedcylinders with hemispherical ends (see Figure 1), andare available in two grades and a range of basiccapacities (see Tables 1 and 2). Other tanks betweenthe basic capacities are available to order.

Table 1 Grade selection (all capacities)

Maximum invert depth of inlet pipe Grade(mm)

1.0 standard

1.5 heavy

1.2 The centrifugally cast cesspools are manufacturedin sections from filled, cold-setting polyester resin andglass-fibre rovings which are sprayed onto the surface ofa rotating mould. The sections are joined by a gluedsocket and spigot type joint.

1.3 Each cesspool is provided with one or two 610 mmdiameter flanges to accept the access shaft(s). Accessshaft assembly kits are supplied with each tank. Theseconsist of a cylindrical shaft of 600 mm internal diameterwith two 110 mm diameter PVC-U sockets toBS EN 1401-1 : 1998 for fitting the inlet and ventilationpipework, and mastic sealant for sealing the shaft intothe flange.

Figure 1 Klargester 18180 litre cesspool

Klargester pedestrian-duty castiron cover and frame

third pourof concrete

second pourof concrete

first pour ofconcrete

as-dugbackfill

minimum 225 mmconcrete bed

• THIS DETAIL SHEET REPLACES DETAIL SHEET 3 AND RELATES TOKLARGESTER CESSPOOLS AND 600 mm DIAMETER LOCKABLEPEDESTRIAN-DUTY COVER AND FRAME.• The cesspools are of glass-reinforced polyester (GRP) and are availablein standard and heavy duty grades and capacities 4000 to 12000gallons (18180 to 54540 litres).• They are suitable for the collection of wastewater and sewage fromdomestic buildings.• The product is manufactured by Klargester Environmental Ltd. It is alsomarketed by Klargester Ireland in Newry, Co Down.

This Detail Sheet must be read in conjunction with the Front Sheet and DetailSheet 1, which give Conditions of Certification and the product’s positionregarding the Building Regulations, respectively.

Certificate No 86/1700

DETAIL SHEET 9Klargester Environmental Ltd

KLARGESTER CESSPOOLS

Product

CI/SfB

(52.3)

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1.4 Access to the cesspool is provided by a lockablepedestrian-duty cover and frame to suit the 600 mmdiameter access shaft.

1.5 Quality controls carried out on every tank includevisual checks, water leakage and vacuum tests,thickness tests and weighing the vessel.

2 Delivery and site handling2.1 The cesspools must be handled with rope orwebbing strings and care must be taken to preventdamage or penetration of the vessel by sharp objects.

2.2 The tanks are marked with the marketingcompany’s name, grade, identification code numberand the BBA identification mark incorporating thenumber of this Certificate.

Design Data

3 General3.1 Klargester Cesspools are suitable for thecollection of waste water and sewage fromdomestic buildings.

3.2 Usage requirement is to BS 6297 : 1983.Attention should be paid to site location to:avoid superimposed loads from vehicles, etc where thecesspool is not adequately protected (see section 3.3)provide adequate venting arrangementsensure the site is not prejudicial to the health of anypersonensure there will be no contamination to anyunderground water or water supplyensure adequate means of access for emptying, iewithin 30 m of a vehicle access without the contentsbeing taken through a dwelling or place of work.

3.3 Unless suitably designed protection in the form of areinforced concrete surround, including an appropriate

cover, is provided, precaution should be taken toprevent the tank being subjected to superimposed loadsby vehicles.

3.4 The use of cesspools is not permitted inScotland.

4 Strength4.1 The manufacturer’s design code has been assessedand found to be satisfactory.

4.2 The tank has adequate impact resistance to avoiddamage under normal site handling conditions.

4.3 The cover and frame assembly is suitable for usewhere subject to foot traffic only.

5 Resistance to chemicalsThe cesspools are resistant to the small quantities ofacid, alkali or other substances to which they maynormally be exposed through contact with domesticsewage.

6 WatertightnessThe construction of the cesspools will not allowseepage either into or from the surrounding soil.

7 EmptyingKlargester Cesspools are emptied easily byremoving the manhole cover and lowering ahose from a suction emptier. Care must be taken

to prevent damage by the hose nozzle.

8 SafetyAccess covers and frames provided for the tanks are notcovered by the scope of this Certificate. They must be ofdurable quality, provide protection against entry andhave the necessary strength for use in the location inwhich the tank is situated.

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Table 2 Dimensions

Centrifugally cast tanksCapacity Overall Outside Ribs Weight (kg) No of

length diameter accessexcluding shafts

ribs number spacing standard heavy(litres) (gals) (mm) (mm) (mm)

18180 4000 4320 2620 3 770 684 747 15305 2330 8 425 505 540 1

22500 5000 5090 2620 4 770 876 959 16185 2330 9 425 642 675 1

27280 6000 6190 2620 6 770 1152 1262 17435 2330 13 425 750 790 1

36370 8000 7740 2620 9 770 1488 1632 19555 2330 18 425 1005 1035 1

45460 10000 9460 2620 12 770 2010 2206 111255 2330 22 425 1150 1230 1

54550 12000 11180 2620 15 770 2210 2426 114230 2330 29 425 1500 1600 1

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9 DurabilityThe structural properties of the GRP from whichthe tank is constructed, in common with all othersimilar materials, will deteriorate with time. This

deterioration is accelerated by contact withgroundwater, sewage and dissolved or suspendedorganic or inorganic compounds. The resulting loss ofstrength and stiffness has been taken into account in themanufacturer’s design code. In the opinion of the BBA,the product, when used in the context of, and installed inaccordance with, this Certificate, will have a life inexcess of 30 years.

Installation

10 General10.1 The manufacturer provides a service whichincludes site investigation, design, installation, sitesupervision, etc. Installation must be strictly inaccordance with the Certificate holder’s instructionsKlargester Cess Pools Installation Procedures.

10.2 The tank must not be installed at a depth greaterthan that specified in Table 1.

10.3 It is essential to take precautions to preventdamage by site traffic.

11 Method11.1 The excavation must be of sufficient size to permiteasy placing of the tank and subsequent backfilling ofthe tank, and for timbering and sheeting. The excavationdepth must be as specified by the manufacturer for thesize of tank being installed. Where groundwater ispresent a well point should be provided to remove wateruntil the concrete bed and the backfill have set. Thepump outlet must be well away from the excavation ordownhill from the site. Pumping should take placecontinuously during the installation procedure.

11.2 A bed of medium workability concrete (sulphateresisting if required) is laid, a minimum 225 mmthickness, level to the correct depth below the draininvert. In saturated ground, the bottom of the excavationshould be covered with a 150 mm layer of consolidatedhard core and the entire excavation lined with polythenesheeting prior to laying the concrete bed.

11.3 The tank is positioned using lifting gear andsuitably-rated webbing strips (see Table 2 for weight oftank supplied). The tank is lowered into the excavationand bedded on the wet concrete.

11.4 The incoming drain is lined up with the inlet pipeconnection. The tank must be upright and truly vertical.Strut firmly with timbers if required. The concrete isallowed to set.

11.5 The excavation is backfilled to invert depth withstructural concrete in 200 mm thick layers, the concreteis tamped down between the layers. Water is run intothe tank to keep pace with, and be slightly ahead of,the tank backfill. Poker vibrators must not be used, theycan damage the tank walls and create flotation in theconcrete.

11.6 The sheeting and strutting is removed carefullybefore concrete set prevents it, the tank must not moveposition during the operation. If necessary (ie in running

sand) the sheeting is raised as the concrete level israised.

11.7 Inlet pipework is aligned and connected using110 mm diameter PVC-U pipe or other suitable pipewith a short length of 110 mm diameter PVC-U pipeand adaptors as required. A short length of pipe withflexible joints must be used adjacent to the tank to allowfor any minor differential movement.

11.8 When extension shafts are supplied separately tofacilitate transportation of the cesspool, the extensionshaft(1) to the access shaft is fitted by placing mastic stripbetween the flanges and tightening the bolts uniformlyand sufficiently to ensure a continuous bead of mastic isvisible inside the shaft.

(1) Additional extensions to the supplied tank access shaft(s)are not permitted under any circumstances as the tank must notbe installed at a deeper invert than specified for the tanksupplied.

11.9 The access shaft is trimmed to a suitable height,using a fine-tooth saw, to enable a cover and frame tobe installed.

11.10 Structural concrete is poured around the accessshaft to a minimum 150 mm thickness, to the undersideof the cast iron frame and allowed to set. The remainderof the excavation is backfilled with pea-shingle or as-dugmaterial, if suitable.

11.11 The manhole cover is fitted into the frame.

11.12 When installed in areas subject to superimposedloads, eg traffic loads, within an area 3 m from themaximum plant perimeter, a reinforced concrete slab ofsuitable design should be provided to ensuresuperimposed loads are not transmitted to the top orside walls of the unit.

11.13 Pumping from the excavation should continue,when necessary, until the concrete surround has fully set,or the tank is full of water.

11.14 The tank must not be emptied for use until theconcrete has cured sufficiently. More time must beallowed for concrete to cure during cold weather, and itmust be protected from frost, after installation duringwinter months, by covering the top of the silage tank.

Backfill specifications11.15 Concrete should be in accordance withBS EN 206-1 : 2000.

11.16 Polythene sheet, building quality 500 gauge, isrecommended.

Technical Investigations

The following is a summary of the technicalinvestigations carried out on the Klargester Cesspools.

12 Tests12.1 The following tests were carried out inaccordance with MOAT No 9 : 1973:(1) Resin/glass ratio, based on ISO 1172 : 1975.(2) Barcol hardness, based on BS 4549-1 : 1970.(3) Cross-breaking strength by water boil, based onmethods in BS 3532 : 1990, Appendix C andBS 2782-3 : Method 304B : 1970.

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On behalf of the British Board of Agrément

Date of issue: 12th December 2002 Chief Executive

(4) Degree of cure, by the Coggeshall test.(5) Water soak test, based on ISO 62 : 1980.(6) The durability of the GRP on prolonged exposure towater was assessed by exposing samples to boilingwater for 1000 hours and then measuring any loss incross-breaking strength, bending stiffness or ductility.(7) Watertightness.(8) Strength of cover and frame assemblies.

12.2 Vacuum testing of complete tanks was carried outto check the validity of the manufacturer’s design, withrespect to buckling and fracture of the tank, whensubjected to external pressure.

13 Investigations13.1 Assessments were made of:(1) the structural calculations and assumptions made inthe design of the cesspool, and(2) the durability of the cesspool in relation to chemicalattack by effluents and groundwater, and in relation tolong-term loading.

13.2 The manufacturing process was examined,including the methods adopted for quality control, anddetails obtained of the quality and composition of thematerials used.

13.3 Visits were made to sites to assess thepracticability and ease of installation.

13.4 A survey was undertaken of existing sites toassess the performance of the product in use.

Bibliography

BS 2782-3 : Method 304B : 1970 Methods of testingplastics — Determination of flexural properties of rigidplasticsBS 3532 : 1990 Method for specifying unsaturatedpolyester resin systemsBS 4549-1 : 1970 Guide to quality controlrequirements for reinforced plastics mouldings —Polyester resin mouldings reinforced with chopped strandmat or randomly deposited glass fibresBS 6297 : 1983 Code of practice for the design andinstallation of small sewage treatment works andcesspoolsBS EN 206-1 : 2000 Concrete — Part 1 :Specification, performance, production and conformityBS EN 1401-1 : 1998 Plastics piping systems for non-pressure underground drainage and sewerage.Unplasticized poly(vinylchloride) (PVC-U) —Specifications for pipes, fittings and the systemISO 62 : 1980 Plastics — Determination of waterabsorptionISO 1172 : 1975 Textile glass reinforced plastics —Determination of loss on ignitionMOAT No 9 : 1973 Directive for the Assessment ofGlass-Reinforced Polyester for Use in Building

British Board of AgrémentP O Box No 195, Bucknalls LaneGarston, Watford, Herts WD25 9BAFax: 01923 665301

©2002For additional information about theCertificate, tel: 01923 665300.For information about AgrémentCertificate validity and scope,tel: Hotline 01923 665400, orcheck the BBA website.

e-mail: mail@bba.star.co.ukwebsite: www.bbacerts.co.uk

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