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Certification Guidelines for PlasticGeomembranes Used to Line Landfills and

Contaminated Sites

Editor: W. W. MüllerPublished by Laboratory IV.32, Landfill Engineering

English Translation of the Second Revised Edition, 09/99

Federal Institute forMaterials Researchand Testing

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Federal Institute for Materials Research and Testing (BAM)

Certification Guidelines for Plastic Geomembranes Used to Line Landfills andContaminated Sites

Editor: W. W. MüllerPublished byLaboratory IV.32Landfill EngineeringUnter den Eichen 87D-12205 BerlinTelephone (030) 8104-1432Telefax (030) 8104.1437

English translation of the Second Revised Edition, September 1999Translated by D. Etter

The complete text of the Certification Guidelines and the listing of certifiedgeomembranes and protective layers can be found in either of the following WWWaddresses: bam.de\deponietechnik.htm (WWW address of BAM) and deponie-stief.de(WWW address with extensive information on landfill technology). The address akgws.de(WWW address of the AK GWS industry association) provides information on certifiedgeomembrane manufacturers and installers.

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Introduction to Second Edition

The first Certification Guidelines for PlasticGeomembranes were published by the LandfillEngineering Laboratory of the Federal Institute forMaterials Research and Testing (German acronym:BAM) in 1992. The Guidelines contributed tooptimization of installation procedures andestablishment of high quality standards forcomposite liner systems. A great number ofsuccessful lining systems have been realised sincethat time. Today the preparation work, processtechnology and equipment, sequential installationplanning and quality management measuresrequired to ensure composite liner systems meetingthe most stringent requirements are known in detail.The resulting liner system is a technically matureand highly effective solution for base lining oflandfills. Plastic geomembranes are also well suitedfor use in cap liners due to their excellentperformance properties. In this sector they can beused in composite liner systems (TechnicalDirective Waste, Technical Directive MunicipalWaste, Landfill Class II) or, e.g. when used to linecontaminated land, can be used either alone or inconjunction with other components such as GCL'sor capillary barriers. The BAM certification proce-dure has contributed significantly to the success ofplastic geomembranes in this wide range ofapplication sectors.

Plastic geomembranes used in landfill liners mustbe carefully selected to ensure long-term functionlong beyond their operative and post-operativecontrol phases. For this reason German federal (TDMunicipal Waste, TD Waste) and state regulationscall for evaluation of suitability by certification of theplastic geomembranes and jointing technologyused. Using these waste disposal regulations as abasis, the BAM landfill engineering laboratory inconjunction with its Advisory Council has created acertification system which is subject to constantrefinement. In recent years changes and additionsto the certification system have been implementedin conjunction with the Advisory Council, includingrequirements for textured geomembranes, protec-tive layers, installation contractors and third-party

inspectors. This revised second edition of the BAMcertification guidelines includes these modifications.

The basic premise of the guidelines howeverremained unchanged: evaluation of suitability foruse in a landfill liner must not be limited to theplastic geomembrane as such. The evaluation mustalso take into account the functional interaction ofthis single component with the overall system.Along with resin and production processspecifications (which are required to withstand thecomplex stressing modes found in landfills andcontaminated sites), quality control measures mustalso be specified to ensure workmanlikeinstallation, effective quality assurance andworkmanlike placement of protective layers. BAMcertifications are now recognised and used by allGerman federal states as proof of suitability inaccordance with the state of the art. For applicantfirms this means that the cost and effort associatedwith geomembrane certification are compensatedby the benefit of commercial access to the entiresector of municipal and industrial waste landfillsand contaminated site lining.

This revised second edition of the Guidelines givesthe requirements for BAM certification as they haveevolved from certification practise to date and asdictated by the state of the art. The requirementshave been formulated as concisely as possible. Onthe other hand, conformance with existingstandards, guidelines and regulations was strivedfor when not in conflict with established qualitystandards. The requirements for protective layerswill be defined in separate certification guidelines.

The accepted state-of-the-art resins for plasticgeomembranes, certain grades of low-pressurepolymerized polyethylene with carbon black UVstabilization, have been established for many yearsand their utilization was presumed in thecertification requirements. However the require-ments can be applied in an analogous manner toother materials as well.

On occasion the use of geomembranes made fromrecycled resin materials has been called for in cap

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liner applications due to the reduced level ofchemical attack encountered here. While justifiedfrom the point of view of waste material utilization,this would conflict with the need for defined andpredictable performance as evaluated by long-termperformance testing, which is a crucial part of allcertification procedures. Accordingly, the recycledresin materials currently available are not suitablefor use.

The BAM certification requirements are by nomeans "irrevocable"; on the contrary they must berevised in accordance with progress in the state ofthe art. These revisions are carried out inconjunction with the Advisory Council, a workingcommittee which advises BAM in certificationmatters. The Advisory Council is chaired by arepresentative from the German FederalEnvironmental Ministry and is made up of membersfrom resin manufacturers, geomembrane manu-facturers, installation contractors, consultingengineers and testing institutes involved in designand third-party control, state authorities and BAM.The diverse nature of this forum is intended topromote acceptance of novel, economicallyattractive and technically secure solutions in thelandfill lining industry.

The following Advisory Council members andguests participated in the consultations: Dipl.-Ing.K.-H. Albers, Naue-ITB (Isolierungsgesellschaft fürTunnel und Bauwerke) GmbH, Ing. K. Bohaty,

AGRU Kunststofftechnik GmbH, Dipl.-Ing. W.Bräcker, Lower Saxon State Bureau for Ecology,Dr. B. Engelmann, Federal Environmental Ministry,B.S.Ch.Eng. D. Etter, GSE Lining TechnologyGmbH, Dipl.-Ing. L. Glück, South German PlasticsCenter (SKZ), Herr R. Hartmann, FUB Gesellschaftfür Folientechnik und Bautenschutz mbH, Dr. G.Heerten, Naue Fasertechnik GmbH & Co KG, Dipl.-Ing. G. Heimer, State Material Testing Institute ofDarmstadt, Dipl.-Ing. A. Hutten, DSM PolyolefineGmbH, Dipl.-Ing. W. Karczmarzyk, IngenieurbüroWersche GmbH, Dr. F. W. Knipschild, Ingenieur-büro und Prüflabor für Kunststofftechnik imBauwesen, Dr. G. Koch, formerly of Hoechst AG,Dipl.-Ing. B. Kopp, Naue-ITB (Isolierungsgesell-schaft für Tunnel und Bauwerke) GmbH, Dr. G.Lüders, BAM, Dr. W. Müller, BAM, Ms. Dipl.-Ing. V.Olischläger, Naue Fasertechnik GmbH & Co. KG,Dipl.-Ing. R. Preuschmann, BAM, Dipl.-Ing. W.Quack, Dow Deutschland Inc., Dr. F. Sänger,Ingenieurgesellschaft für Wasser und TiefbaumbH, Dipl.-Ing. R. Schicketanz, IngenieurbüroSchicketanz, Dr. S. Seeger, BAM, Dipl.-Ing. E.Spitz, Hermann Stumpp GmbH & Co KG.

The following employees of the Landfill TechnologyLaboratory were also involved in editing theGuidelines: B. Büttgenbach, I. Jakob and Dipl.-Ing.R. Tatzky-Gerth.The English translation was done by D. Etter.

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Table of contents

1. Legal Basis, Area of Validity and Regulations.................................................................................. 62. Objects Certified ............................................................................................................................... 7

2.1 General Information .................................................................................................................. 72.2 Resin ..................................................................................................................................... 72.3 Dimensions ............................................................................................................................... 82.4 Surface Texturing ..................................................................................................................... 82.5 Identification Markings and Protective Strips............................................................................ 82.6 Manufacturing Process and Site............................................................................................... 82.7 Jointing Technology.................................................................................................................. 9

3. Applicant and Certification Holder .................................................................................................... 94. Testing Procedures and Equipment ....................................................................................................... 9

4.1 General Physical Requirements ............................................................................................... 94.2 Mechanical Requirements ........................................................................................................ 94.3 Requirements for Physical Resistance and Long-Term Behaviour............................................... 104.4 Requirements for Textured Geomembranes............................................................................ 10

4.4.1 Texturing Resins ........................................................................................................... 104.4.2 Additional Requirements............................................................................................... 10

5. In House Quality Control and Third-Party Inspection....................................................................... 116. Installation Requirements ................................................................................................................. 12

6.1 General Information .................................................................................................................. 126.2 Requirements for Installation Contractors ................................................................................ 136.3 Self-Testing and Third-Party Inspection ................................................................................... 136.4 Information on Planning............................................................................................................ 136.5 Support Surface for Geomembranes........................................................................................ 14

6.5.1 Surface Requirements for Clay Liners.............................................................................. 146.5.2 Surface Requirements for Other Support Layers ............................................................. 14

6.6 Transport and Storage.............................................................................................................. 156.7 Installation................................................................................................................................. 156.8 Welding and Site Testing.......................................................................................................... 166.9 Protective Layers ...................................................................................................................... 17

7. Changes, Period of Validity and Notification of Deficiencies............................................................ 178. Requirement Tables ......................................................................................................................... 18

Table 1: General Physical Requirements......................................................................................... 18Table 2: Mechanical Requirements.................................................................................................. 20Table 3: Requirements for Physical Resistance and Long-Term Behaviour ................................... 21Table 4: Additional Requirements for Textured Geomembranes..................................................... 23Table 5: Test Procedures and Frequencies for Incoming Quality Control

of Resin and Carbon Black Batch ...................................................................................... 24Table 6: Test Procedures and Frequencies for In-House Quality Control

of Geomembranes by Manufacturer................................................................................... 25Table 7: Test Procedures and Frequencies for Third-Party Inspection

of Resin, Carbon Black Batch and Geomenbranes ........................................................... 279. Standards, Guidelines, Official Gazettes and Recommendations ................................................... 2810. Appendices to Certification Report, Numerical Codes for

Federal States and Test Institutes .................................................................................................... 30

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1 Legal Basis, Area of Validity andRegulations

The avoidance, utilization and disposal of wastematerials is governed by applicable federal laws.The Waste Act (Section 4 Par. 5 AbfG) of 27August 1986 and the Recycling and Waste Act of27 September 1994 (Section 6 Par. 2, Section 12Par.2 KrW-/AbfG), which now has come into effect,specify the enabling standards for the issuance ofstatutory orders and general administrativeregulations. Section 12 Par. 2 of the KrW-/AbfG(previously Section 4 Par. 5 AbfG) provides thelegal basis for the Second General AdministrativeRegulation for the Waste Act (TD Waste) and theThird General Administrative Regulation for theWaste Act (TD Municipal Waste). These twoadministrative regulations were issued primarily toregulate landfill construction uniformly throughoutGermany for industrial and municipal wastes.

Subsection 10.4.1.1, Paragraph 4 of TD MunicipalWaste specifies use of certified plastic geo-membranes only. Appendix E of TD Waste, whichis also referenced in TD Municipal Waste, statesthat the proof of suitability of the plasticgeomembranes must be furnished by means of acertification document. Both TD Waste and TDMunicipal Waste specify BAM as a suitablecertification authority for plastic geomembranes.In accordance with this legal basis and thetechnical basis specified in the following text, BAMtests the suitability of plastic geomembranes and ifapplicable the jointing technology as applied for bythe manufacturer and documents the suitability in acertification document.

Landfill liner systems must be constructed inaccordance with the state of the art. TheseCertification Guidelines describe the requirementsthat must be fulfilled in installation of certified plasticgeomembranes to provide a state-of-the-art linersystem. These requirements are also referred toexpressly in the certification document. Theapproving authorities of the states must see to itthat these references are included in the landfillpermit, therefore making them legally binding. Thisis a prerequisite for use of BAM certification as

proof of suitability of the geomembrane-based linersystem.

BAM when issuing certifications expressly reservesthe right of revocation. Grounds for revocation aregiven if the manufacturer deviates from theprocedures specified in the test reports andappendices of the certification document, the rawmaterials as used in the sample tested or otherrequirements specified in the certificationdocument. Should that be the case, furtherproduction of these geomembranes identified withthe BAM certification number is prohibited.

Changes in either the raw material or productionprocess of the plastic geomembrane or dispositionsfor in-house quality control and third-partyinspection of production require new certification. Ifinstallation and welding equipment used by themanufacturer and installation contractor provessubstandard as shown by new technical findings,i.e. if the technical situation (state of the art) and thelegal situation have changed such that issuance ofcertification would no longer be possible, this aswell is grounds for revocation.

In the event of revocation the manufacturer isobligated to immediately return the certificationdocument to BAM.

BAM certifications are based on the following laws,regulations and guidelines in their currently validversions:

1. The Act for Avoidance, Utilization and Disposalof Waste Materials (Recycling and Waste Act -KrW/AbfG) of 27 September 1994,Bundesgesetzblatt I, p. 2705, 1994

2. The Third General Administrative Regulation forthe Waste Act (TD Municipal Waste), TechnicalDirective for Utilization, Treatment and OtherDisposal of Municipal Waste of 14 May 1993,Bundesanzeiger No. 99a, 1993.

Information for the implementation of TD MunicipalWaste is given in:

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2.1 Requirements for Municipal Waste Landfills inLower Saxony, Landfill Manual, published by theLower Saxon State Bureau for Ecology,Hildesheim, 1994.

2.2 Notice Concerning the Application of TD Wasteto Landfills, Notice No. 12, published by the StateEnvironmental Ministry of North Rhine-Westphalia,1998.

3. The Second General Administrative Regulationfor the Waste Act (TD Waste, Part 1), TechnicalDirective Concerning Storage, Chemical/Physicaland Biological Treatment, Incineration andDisposal of Waste Materials Requiring SpecialControl of 12 March 1991, Joint Ministerial GazetteNo. 8, p. 139, 1991.

4. Administrative Regulations of the ThuringianMinistry for Environment and State Planning -Controlled Waste Disposal – of 11.09.1992,Thuringian State Gazette No. 40, p. 1344, 1992.

5. Certification Guidelines for PlasticGeomembranes Used to Line Landfills andContaminated Sites, Federal Institute for MaterialsResearch and Testing (BAM), September 1999.

6. Requirements for Protective Layers OverGeomembranes in Composite Liner Systems,Certification Guidelines for Protective Layers,Federal Institute for Materials Research andTesting (BAM), August 1995.

7. Third-Party Inspection of Installation of PlasticComponents in Landfill Lining Systems, Guidelinesof the Federal Institute for Materials Research andTesting (BAM) Concerning Requirements forQualification and Activities of Third-PartyInspectors, August 1998.

For further information and updates on the abovedocuments as well as for a list of BAM-certifiedgeomembranes and third party inspectors, see ourhome page: www. bam.de\deponietechnik.htm.

2 Objects Certified

2.1 General InformationThe objects certified are plastic geomembranesused in base and cap liners of landfills and forcontainment of contaminated sites.1

The geomembranes are described by explicitspecifications in the certification document coveringthe resin used in production, dimensions, surfacetexturing and the production process. Thegeomembranes must carry identification markingsand incorporate protective strips on their edges.The geomembranes must fulfil the requirementsgiven in these guidelines and their production mustbe subject to in-house quality control and third-partyinspection within the framework of a qualitymanagement system.BAM must be notified of and approve of anychanges in the above. Should the manufacturer notnotify BAM of such changes, the certificationbecomes invalid.

2.2 ResinThe manufacturer is obligated to explicitly identify inwriting the resin used in geomembrane production.

Both pre-compounded resins and resins requiringaddition of masterbatch in geomembrane manu-facturing can be used. The masterbatch employedmust be approved by the manufacturer of the basepolymer. The manufacturers of the base polymerand the carbon black batch must contractuallycommit to notify BAM in due time of any change inthe formulation of products supplied.

The batch shall incorporate a tracer additivedefined in conjunction with BAM to ensure clearidentification in the geomembrane.

When applying for certification of the geo-membrane, the manufacturer must submit datasheets on the resins and additives employedcontaining at least the following information:

1 referred to hereinafter as geomembranes

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1. Resin type, in the case of HDPE in accordancewith DIN 16776-1, and exact description and weightpercentage of the additives2. Molecular weight distribution3. Specification of properties given in Table 5

This data will be confirmed by BAM by directcontact with the resin and batch manufacturers.The descriptions and weight percentages of theadditives, molecular weight distributions and allother special data concerning resins and batches,i.e. the complete formulation, will be treatedconfidentially by BAM.

The content of recycled material from theproduction process (e.g. from edge trimming) maynot exceed 5 wt %. The maximum permissiblecontent will be specified in the certificationdocument.

Use of regenerated resins, e.g. post-consumerscrap, is not permitted.

2.3 DimensionsThe maximum length per geomembrane roll andthe width and thickness will be given in thecertification document. The specifications fornominal, average and individual thickness valuesare given in Table 1. A basic requirement is that theminimum thickness must be at least 2.50 mmregardless of whether the geomembrane is smoothor textured. The minimum permissible width of thegeomembrane is 4.5 m.

2.4 Surface TexturingGeomembranes may incorporate texturing on oneor both sides. Texturing may be formed byembossing during production or by other processeswhich do not impair the material quality or appliedas particles subsequent to production. Specialrequirements for textured geomembranes are givenin Section 4.4.

2.5 Identification Markings and Pro-tective StripsThe geomembranes must have clearly visiblepermanent identification markings approximatelyevery 2 m2. The identification markings must

contain the following information which may beencoded if necessary:

XX/BAMOU/YY/ZZ/Manufacturer'sLogo/Thickness/Width/Resin/Type of Surface/Weekof Manufacture/Year of Manufacture

OU is the organizational unit of BAM issuing thecertification, XX is the federal state code and ZZ isthe year of issuance of the certification.

The geomembranes must incorporate a 15 cmprotective strip in the smooth land area to protectagainst surface contamination. The protective stripis applied in production. Adhesion must besufficient to prevent separation during transport andsite handling but must not leave residues on thesurface of the geomembrane when removed.

2.6 Manufacturing Process and SiteThe manufacturing site and a detailed description ofthe manufacturing process are fixed as described inthe certification document. If requested by theapplicant firm, any details concerning theirmanufacturing process will be treated confidentiallyby BAM.

Prior to issuing certification, BAM will visit themanufacturing site to verify the information providedon the manufacturing process and machines. BAMalso checks that qualified personnel, machines,buildings, equipment for resin (base polymer andbatch) storage and handling, testing machines andother equipment are such as to ensure satisfactoryproduction and in-house QC in accordance with therequirements of Tables 5 and 6.

The manufacturer must demonstrate how hismanufacturing process prevents defective pro-duction (e.g. due to moisture in resin2, thickness

2 Batches containing carbon black are particularlyhygroscopic. Storage of such materials in dry areasor in closed bags is not sufficient to preventmoisture absorption. Therefore predrying forexample by a continuous-operation dry air dryer isrequired or e.g. a degasification zone must bepresent on the extruder.

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variations, surface damage3) by manufacturingprocedures and quality management.

2.7 Jointing TechnologyJointing of the geomembranes at the site must bedone exclusively by welding. They must be placedwith sufficient overlap and joined by hot-wedgewelding with a test channel (standard weld seams)or by hot air extrusion fillet welding. Other weldingprocesses may be used only if their suitability hasbeen documented and expressly approved by BAM.

3 Applicant and CertificationHolder

The applicant and certification holder is themanufacturer of the geomembrane certified. Thecertified geomembrane must be sold by themanufacturer or a sales representative designatedin the certification document. Geomembranemanufacturers which themselves do not sellgeomembranes must designate at least one salesrepresentative. The sales representative mustprovide documentation of their capability andexperience (e.g. training and experience ofpersonnel, references) in the plastics and landfillsectors.

4 Testing Procedures andEquipment

Testing is carried out by BAM in Laboratory IV.32,Landfill Engineering and in BAM-approved testinstitutions (see Section 10). The LandfillEngineering Laboratory provides supplementaryinformation on tests which are not defined orinsufficiently defined by test standards.4

3 Damage of this type can occur for instance inapplication of texturing particles.4 "Supplementary Information on Tests forCertification of Plastic Geomembranes for LandfillLiners" is available from the Landfill EngineeringLaboratory, IV.32, BAM, D-12200 Berlin/Germany.

The minimum values given in the specificationtables refer to the average value minus thestandard deviation unless otherwise specified.

The test procedures and requirements given in therequirement tables refer normally togeomembranes made from medium to high densitypolyethylene resins in accordance with DIN 16776-1, EACL 35 - 40, T 006 to 022 (HDPE geomem-branes), i.e. with a density (without carbon black)between 0.932 and 0.942 g/cm3 and MFR values(190 °C/5 kg) between 0.4 and 3 g/10 min. Testingof geomembranes made from other resins will bebased on the specifications of the requirementtables. For geomembranes made from HDPE, BAMmay waive the need for the following tests incertification: Table 1, 1.10, Table 2, 2.6, Table 3,3.6, 3.7 and 3.8.

The property values determined in the suitabilitytesting of the geomembranes and tested in in-house QC and third-party inspection are given inAppendix 1 of the certification report.

In substantiated individual cases BAM may makespecial regulations which supplement or vary fromthe technical requirements defined in theseguidelines. These special technical requirementswill be drawn up following consultation anddiscussion with the Advisory Council.

4.1 General Physical RequirementsTable 1, General Physical Requirements, lists theproperties, tests and requirements for the individualtest attributes which characterize the general natureof geomembranes. The following properties aredetermined: surface appearance, material homo-geneity, carbon black content and distribution, skewand waviness, thickness (individual values andaverage), change in melt flow rate due toprocessing, dimensional stability, permeability tohydrocarbons and oxidative stability.

4.2 Mechanical RequirementsTable 2, Mechanical Requirements, lists theproperties, tests and requirements for the individualtest attributes which characterize the mechanicalstress limits of geomembranes. The following

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properties are determined: behaviour under uniaxialand multiaxial deformation, tear resistance, staticpuncture resistance, dynamic puncture resistance(falling dart test), low-temperature behaviour(cryogenic flex), relaxation behaviour and weldseam quality as determined in short-term testing atinstallation sites.

4.3 Requirements for Physical Resis-tance and Long-Term BehaviourTable 3, Requirements for Physical Resistance andLong-Term Behaviour, lists the properties, tests andrequirements for the individual test attributes whichcharacterize geomembranes' resistance to chemi-cals, stress cracking, thermooxidative degradation,weathering, microbe attack, root penetration andlong-term combined stressing. These factorscomprise all significant attack processes to poly-olefinic materials. Prediction of expected service lifeis done on the basis of time-to-failure curves fromlong-term burst tests conducted on pipe specimensextruded or otherwise fabricated from the resinused to make the geomembranes. However,alternative test procedures and requirements tolong-term pipe burst testing are being developed toallow quicker evaluation of resins for which long-term pipe burst test data is not available. The testprocedures under consideration in this regard arestress cracking of notched specimens underconstant tensile loading and oxidative stabilityunder immersion in hot water. The performancerequirements in these tests will be based on theperformance of geomembrane resins which haveproven suitable in long-term pipe burst testing.

In addition a new test procedure has beenintroduced for characterization of the welding pro-perties of various resins.

4.4 Requirements for Textured Geo-membranesRequirements for textured geomembranes and forthe resin making up the texturing depend on thetype of texturing and the fabrication procedureemployed. A test procedure (long-term shear test)is currently being analyzed for evaluation of long-term properties of texturing particles and thereforetheir ability to bear long-term shear force. When

these trials are completed, the requirements inSection 4.4.1 below for texturing resins will beredefined.

4.4.1 Texturing ResinsTexturing material or laminates applied subsequentto production must be made of the resin used tofabricate the base geomembrane or of anotherresin which has been used in certified geo-membranes. Processing of the resin in the textureapplication process must not cause any alterationswhich impair long-term properties, in particular withregard to molecular structure (melt flow rate) oroxidative stabilty (OIT time). Equally, auxiliarysubstances used in the process (e.g. blowingagents, gases etc.) must demonstrably have nodetrimental effects on the materials.

4.4.2 Additional RequirementsThe additional requirements for texturedgeomembranes are given in Table 4.

Bonding between texturing particles and the basegeomembrane must be not be superficial (in whichcase texturing can be removed by simplescratching with a fingernail); the bonding must havecome about from fused interfaces. Auxiliary materi-als, e.g. adhesives, are not permitted.

In general the properties of texturedgeomembranes may not change detrimentally ascompared to those of smooth geomembranes (seeTables 1, 2 and 3) apart from two exceptions asgiven in Table 4: elongation at break in the texturedareas and dimensional stability of embossedtextured geomembranes. In particular the yieldstrength and elongation at yield in uniaxial tensiletesting and the bulge elongation in multiaxial tensiletesting of specimens taken from the textured areasmust fulfil the requirements of Table 2. Thetexturing process must normally leave smooth landareas on the geomembrane for welding. Theproperties characterizing processing, i.e. elongationat break, yield strength and elongation at yield inthe untextured land areas must correspond to thoseof the smooth geomembrane.The test procedures given in Table 3 are normallynot required for textured geomembranes if a certi-

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fied smooth geomembrane is made on the sameproduction line from the resin used to make thetextured geomembrane.

5. In-House Quality Control5 andThird-Party Inspection

QC of incoming raw materials along with regular in-house production QC and third-party inspectionmust be provided for to ensure consistent quality ingeomembrane manufacturing. These activities mustbe conducted in accordance with DIN EN ISO 9002to ensure a quality management system forgeomembrane manufacturing as described in e.g.the DIN standard series DIN EN ISO 9000-1through DIN EN ISO 9004-1. The manufacturer'squality management manual must be submitted toBAM as part of the documentation required forcertification.

The specifications for the resin or base polymer andcarbon black batch are agreed on jointly by themanufacturers of the resin or base polymer andbatch and the geomembrane manufacturer. Thespecifications for density, melt flow rate and carbonblack content of the resin or carbon black batch areentered as such in the certification document. Thisagreement must also provide for acceptance testcertificates on the basis of DIN EN 10204, Section3.1B. The incoming QC of the resin deliveries mustinclude random-sample testing and documentationby the geomembrane manufacturer of processing-relevant properties such as melt flow rate, density,carbon black content of batch and moisture content.The test procedures required and their frequenciesare given in Table 5.

The test attributes given in Table 6 must be testedin in-house manufacturing QC using the proceduresand frequencies given in the table. The test datagenerated both in in-house QC and in the third-party inspection described below must fulfil therequirements and tolerances of the requirement

5 In-house quality control is now referred to in theconstruction sector as "supplier's fabricationcontrol" (as per draft of new DIN 18200 standard).

tables and Appendix 1 of the certification document.The test data must be archived for 20 years fromthe date of testing such as to provide traceability ofthe test results for any given geomembrane roll.This test data must be made available to BAM uponrequest. Each geomembrane roll must be identifiedby a printed identification code as defined in thecertification document applied prior to shipment in aclearly visible location.

An acceptance test certificate must be issued foreach roll shipment on the basis of DIN EN 10204,Section 3.1B. The acceptance test certificate mustclearly identify the specific rolls of those shipped onwhich the test data given was actually determinedand which data apply for other rolls in the pro-duction sequence due to low test frequency (seeTable 6). QC data given in this manner must beprovided for all rolls identified and supplied asBAM-certified geomembranes.

Manufacturing of the geomembranes must besubject to inspection by a third-party instituteapproved by BAM. This institute must havesufficiently qualified personnel, the necessary testequipment, fulfil the requirements of the DIN ENISO 17025 standard and be approved by BAM as athird-party inspector. A prerequisite for this approvalis accreditation for the standard tests conducted inthird-party inspection. The inspection contractbetween the third-party inspector and the geo-membrane manufacturer must be submitted to BAMas part of the documentation required for certi-fication. The inspection comprises testing of thegeomembranes, inspection of their manufacturingand their in-house QC. DIN 18200 applies to theinspection along with any additional requirementsstipulated in the inspection contract between thethird-party inspection and the geomembranemanufacturer. The inspection contract must meetthe following requirements:

1. When sampling the initial production of certifiedgeomembranes, the third-party inspector mustcheck that prerequisites are fulfilled for propermanufacturing and in-house QC.2. In third-party inspection all tests given in Table 7must be carried out on the precompounded resin

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(or base polymer and batch) and the geo-membranes. Inspections of the laboratory andproduction must be included as well along with acheck on in-house QC records to monitor the QCsystem and its extent.

3. The third-party inspection must be carried out 2times per year. If the manufacturer produces bothcertified smooth geomembranes and certified oneor two-sided textured geomembrane, third-partyinspection will be carried out 2 times per year oneach, i.e. on the product group "smooth geo-membranes" as well as on the product group"textured geomembranes". The material samplesfor the tests must be taken by the third-partyinspector directly from production.

The inspection visits must normally beunannounced. They must coincide with productionof geomembranes which are intended for use ascertified geomembranes and carry the printed I.D.code given in the BAM certification. The geo-membrane manufacturer must therefore provide thethird-party inspector production plans for all BAM-certified geomembrane in due time to permit properscheduling of inspection visits. Proof of completedthird-party inspection will be furnished by inspectionreports which the inspection institute will provideregularly and of their own accord to BAM. This mustbe stipulated in the inspection contract. In the eventdeficiencies are discovered, the inspection institutewill decide on the necessary measures to be taken.Should repeated or serious deficiencies bediscovered, the inspection institute must informBAM accordingly.

6 Installation Requirements

6.1 General InformationLandfill liner systems must be fabricated inaccordance with the state of the art. Thegeomembranes used must be certified for thisapplication sector. Geomembranes are installed inaccordance with the state of the art only if thefollowing requirements6 are met and stipulated in

6 See in addition Appendix E of TD Waste and TDMunicipal Waste.

the landfill permit. This is a prerequisite for the useof BAM certification as proof of suitability and utility.This section of the guidelines is therefore of parti-cular interest to approval authorities.

Fulfilment of the requirements must be verified byself-inspection7 on the part of the installationcontractor, by third-party inspection - e.g. by anindependent outside engineering consultant or testinstitute, as directed by the approval authority - andby inspection (normally without need for furthertesting) on the part of the approval authority.

In order to ensure definition of qualitycharacteristics in accordance with the materialsemployed and the state of the art, the requirementsmust be taken into account in planning as well as incompilation of the bidding specifications and thequality assurance plan. Participation of the third-party inspection institute is therefore requiredstarting with the planning stage.

The requirements apply in general to installation ofgeomembranes. When used in base liner systems,the geomembranes are usually employed as part ofa composite liner system, i.e. over a clay liner.When used in cap liner systems, geomembranesare employed as part of a composite liner system, amodified composite liner system in which the clayliner is replaced by a GCL, liner systems com-prising geomembranes installed in conjunction witha capillary barrier and lining systems comprisingonly geomembranes.

When geomembranes are installed as part of acomposite liner system, the goal in design is toutilize the weight of the components above - e.g.protective and drainage layers, waste material andlandscaped topsoil layers - to ensure full-surfacecontact between the geomembrane and the clayliner. This smooth configuration, also referred to asintimate contact, prevents spreading of leakagefrom possible holes or damage between the two 7 These terms are used as defined in TD MunicipalWaste, Section 10.4.1.2. The term self-inspection issometimes incorrectly interpreted as meaning self-inspection on the part of the owner by a designatedthird party.

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liners, therefore ensuring the redundancy which isstrived for in a composite liner system. In othercases, e.g. when the geomembranes are installedover a levelling layer or the capillary layer of acapillary barrier, the requirement for a smoothconfiguration of the geomembrane is derived fromthe need to prevent waviness or folds arising fromwaviness that would undergo excessive defor-mation due to the weight of the protective, drainageand topsoil layers. The limit for permissibleelongation of HDPE geomembranes under multi-axial loading at 40 °C is 3 %, while the limit undermultiaxial loading at 20 °C is 6 %.

6.2 Requirements for Installation Con-tractorsThe geomembranes must be installed by aspecialist firm using personnel with provenexperience and qualifications equipped with thenecessary machinery and other devices. The re-quirements for installation contractors are describedin BAM recommendations entitled "InstallationContractors for Installation of Plastic Componentsin Landfill Lining Systems". Proof of the requiredqualifications, equipment and experience can beestablished e.g. by inspection by a qualitysupervisory society of an industrial associationdemanding full compliance with the requirements ofthe BAM recommendations and inspection by anindependent test institute recognized for itsexpertise and experience.8

6.3 Self-Testing and Third-Party Inspec-tionFabrication of the liner system must be carried outaccording to a quality assurance plan defining theresponsibilities, equipment and actions required forverifiable attainment of the required qualitycharacteristics. The procedures used must ensure

8 The German industrial association ofgeomembrane manufacturers and installers,Arbeitskreis Grundwasserschutz e.V. (AK GWS),has established a quality supervision system of thistype based on the BAM recommendations. Thequality supervision is realised by auditing andinspection of installation contractors by BAM.Installation contractors maintain their AK-GWSapproved status only if they fulfil the requirementsof the recommendations.

satisfaction of the requirements described in theseguidelines for installation of the geomembranes andthe provisions of the certification document and itsappendices. The quality assurance plan mustprovide for coordinated action between the insta-llation contractor and all other parties at the siteinvolved in multisequential construction processes,e.g. fabrication of the composite liner system. Self-testing by the installation contractor and third-partyinspection in installation of the geomembranesmust be included in the quality assurance plan.

The installation contractor must have a foremanwho is experienced in installation and is responsiblefor self-testing present at the site at all times duringinstallation work.

Third-party inspection must be carried out by aqualified and experienced organization withadequate personnel and equipment. The re-quirements that must be fulflled with regard to thequalifications and responsibilities of the third-partyinspector are described in the BAM Guidelineentitled "Third-Party Inspection in Installation ofPlastic Components in Landfill Liner Systems". Thecommission for the third-party inspector is giveneither by the owner with the consent of the approvalauthorities or directly by the approval authorities.The approval authorities must be kept advised ofand be able to provide input to the third-partyinspection as it progresses.

6.4 Information on PlanningThe soil base must be sufficiently firm such thatcompression from weights bearing above will notcause damage to the lining system. Deformationresulting from such settlement must not exceed thepermissible deformation of the geomembrane.

Calculation of static stability of the liner systemduring construction, eventual intermediate statesand its final state should be conducted according toaccepted procedures, e.g. GDA recommendations9

E-2-7 "Shear Resistance of Lining Systems"10,

9 These recommendations are available from theGerman Geotechnical Society, Essen, Germany(www.dggt.de).10 Bautechnik 75, 1998, Volume 9.

14

E 2-21 "Calculation of Spreading Stability andEstimated Deformation on Landfill Bases" andE 3-8 "Frictional Behaviour of Geosynthetics"11.Dimensioning of any reinforcing elements requiredshould be done in accordance with the GDArecommendation E 7-1 "Static Stability Calculationsof Geosynthetic Reinforcing Components inLandfills"11. Geometric transitions such asembankment toes and heads must be executed inaccordance with the DVS R 2225-4 Guidelines12.

6.5 Support Surfaces for Geomem-branesGeomembranes may be installed only over suitablesupport layers. The support layer may also bedesigned to perform additional functions, i.e. that ofan secondary sealing layer, capillary layer, baselayer or gas collection layer. In composite linersystems the clay liner must meet special re-quirements as described in the following section.For all other support surfaces the requirementsgiven in Section 6.5.2 apply.

6.5.1 Surface Requirements for Clay LinersThe surface of the clay liner must be such that it willnot cause short-term or long-term mechanicaldamage to the geomembranes when joined in full-surface contact (intimate contact). Immediatelybefore installation of the geomembranes, thissurface must be subjected to acceptance inspectionby the site construction supervisor, the installationcontractor and the third-party inspector for plastics.The approval authorities may wish to participate inthis acceptance inspection and should be advisedaccordingly.

The surface is acceptable if it fulfils the followingcriteria:

Physical criteria: the surface must be stablebearing, homogeneous, finely grained and free ofholes; it may not include particles greater than 10mm in diameter or foreign matter; fine gravel

11 Bautechnik 74, 1997, Volume 9.12 The DVS Guidelines are available fromDeutscher Verband für Schweißen und VerwandteVerfahren e.V., Düsseldorf, Germany, (www.dvs-ev.de).

particles must be suspended, i.e. embedded on allsides by cohesive material. The surface must befree of coarse particles and foreign material.

Geometrical criteria: the surface must in general befree of abrupt changes in height. Individual steps(differences in compression) are permissible up to0.5 cm in height. Deviations from level under a 4 mlath (straight edge) may not exceed 2 cm.

Analysis of field trials may provide further project-relevant evaluation criteria.

6.5.2 Surface Requirements for Other SupportLayersThe support layer may be made of noncohesive orweakly cohesive soil materials with a grain sizerange of 0 - 32 mm or of recycled materials such asbuilding rubble, crushed glass or slag in the samegrain size range. The geometric form, grain sizeand grain size distribution of support layer materialsmust be such as to exclude non-permissiblemechanical stressing of the geomembrane. Thismust be verified for the project at hand by amodified plate bearing test13 and selected stressingmodes in the field test plot. The permissiblemechanical stresses for geomembranes and thetest procedures for the modified plate bearing testare given in the BAM Certification Guidelinesentitled "Certification Guidelines for ProtectiveLayers; Requirements for Protective Layers OverGeomembranes in Composite Liners". In modifiedcomposite systems incorporating GCL's in place ofclay liners, the GCL provides mechanical protectionunder the low surface weights bearing on cap linersystems. This effect can be taken into account in

13 Seeger, S. and Müller, W.: Limits of Stress andStrain: Design Criteria for Protective Layers forGeomembranes in Landfill GeomembraneSystems. In: Geosynthetics: Applications, Designand Construction, Proceedings of the FirstInternational European Geosynthetics Conference(Eurogeo 1). DeGroot, M.B., DenHoedt, G., undTermaat, R.J. (Hrsg.). Rotterdam: A. A. Balkema1996 andSeeger, S. and Müller, W.: Requirements andTesting of Protective Layer Systems forGeomembranes. Geotextiles and Geomembranes,14(1996), H. 7-8, S. 365.

15

selection of support layer materials with regard tograin geometry, grain size and grain distribution.

The slopes and radii of curvature of the supportlayer must conform to those given in the QA plan.The measured height at any point may not deviatefrom specified height by more than 3 cm. Steps,compression marks and ridges may not be largerthan 2 cm. Certain support layer materials (e.g.very rigid materials) may require case-by-caseevaluation with regard to the need for stricterdimensional tolerances to avoid non-permissiblestresses. In modified liner systems incorporatingGCL's in place of clay liners, the requirements forthe support layer under the GCL must be met asgiven in the relevant guidelines, recommendationsand construction-sector certifications.

6.6 Transport and StorageThe transport and storage instructions forgeomembrane rolls are given in the appendix to themanufacturer's certification document. The qualityassurance measures defined for the site mustensure that these instructions are followed.

Transport of geomembrane rolls to the site and onthe site must be done only by the installationcontractor or personnel trained by the installationcontractor using suitable transport equipment (e.g.lifting traverse) in accordance with the transportinstructions of the geomembrane manufacturer.

A acceptance certificate based on DIN EN 10204-3.1 (as described in Section 5) must be provided tothe third-party inspector for each shipment alongwith the shipping documents.

Storage of the geomembrane rolls must be such asto prevent denting from stones, foreign material,support boards etc. as well as non-permissibledeformation of the stacked rolls. A suitable storagearea must be prepared at the site prior to delivery ofthe geomembrane rolls.

6.7 InstallationBefore installation of the geomembrane rolls, theinstallation contractor and the third-party inspectormust check that they fulfil the requirements of its

certification document and the project specificationsand that the geomembrane rolls are not damaged.During installation of the geomembrane rolls, acomplete copy of the certification document mustbe available at the site.

Installation must be carried out according to aninstallation plan approved in advance by the third-party inspector and the approval authority. Wheninstallation is complete, the plan is modified asnecessary, providing the final diagram of theinstalled liner system. Important principles to befollowed in installation and connection to structuralcomponents are illustrated in the DVS R 2225-4Guidelines. Normally the geomembrane must beincluded in the field test plot made for the clay linerin order to optimize installation with regard to theother liner system components. Handling of therolls in installation must be done only by theinstallation contractor or personnel trained by theinstallation contractor using suitable transportequipment (e.g. lifting traverse) in accordance withthe transport instructions of the geomembranemanufacturer. Devices to control unrolling may berequired on long or steep embankment slopes.

The geomembranes must be installed with minimalwaviness to ensure a smooth configuration over thesupport layer after placement of the protectivedrainage layer. This requires correct timing of theinstallation work, i.e. utilization of daily temperaturecycling (the coefficient of linear thermal expansionof HDPE geomembrane is 1.5 - 2.5 ⋅104 K-1 over atemperature range of 20 °C to 70 °C).

Experience has shown that waves up to severalcentimeters in height can be eliminated by waitingfor ambient temperature to cool off later in the day.

Waves in HDPE can not be smoothed out by simplyloading from above. Even heavy loading isineffective since HDPE is practically incompressible(Poisson ratio: 0.49). Weighing down long, highwaves transforms them to small but very steepwaves, causing high flexural strain in thegeomembrane14. The timing and application 14 The magnitude of the strain is described inSoong, T.-Y. and Koerner, R., Behavior of Waves in

16

sequence in placement of the protective layer andthe drainage layer are particularly important in thisregard. This therefore must be done in thepresence of the third-party inspector.

Care must be taken that flow or accumulation ofcondensate under the geomembrane does notdamage the clay liner, i.e. impair full-surfacecontact.

A special installation procedure known as “securedmodular installation ”has proven beneficial in thisregard while still permitting fast installation rates, asdescribed in15.

Installation normally may not take place duringprecipitation of any kind or over areas with standingwater. Welding is not permissible at ambienttemperatures below the dew point. Large-areainstallation of geomembranes is normally onlypossible from April to October. Installation in othermonths is possible only under unseasonablyfavourable weather conditions. Protection againstinclement weather (e.g. a tent or heated tent) isnormally required. Installation outside of the periodApril to October may be done only with the consentof the approval authority and the third-partyinspector.

High Density Polyethylene Geomembranes: aLaboratory Study. Geotextiles and Geomembranes178 (1999) pp. 81-104.15 Averesch, U.B. and Schicketanz, R., InstallationProcedure and Welding of Geomembranes in theConstruction of Composite Landfill GeomembraneSystems – Focus on “Riegelbauweise”. FromProceedings of the 6th International Conference onGeosynthetics, Atlanta, 1998, published by Rowe,R.K., Industrial Fabrics Association, Rosewill, USA,1998;Corbet, S.P. und Peters, M.: First Germany/USAGeomembrane Workshop. Geotextiles andGeomembrane, 14(1996), H. 12, S. 647-726;Dornbusch, J., Averesch, U. and El Khafif, M.,Construction Procedures and Quality Managementin Fabrication of Composite Liners for Landfills.Forschungsvereinigung Baumaschinen undBaubetrieb e.V., Aachen/Germany, 1996. Thisstudy was conducted as part of the BMBFResearch Project entitled “Continuing Developmentof Landfill Liner Systems”.

Each geomembrane when installed is given anidentification number in the final diagram of theinstalled liner system. These identification numbers,the identification markings and the manufacturer’sroll numbers given in the shipping documents mustprovide full traceability of all geomembranes. Anydamage to geomembranes which impairs sealingintegrity or mechanical strength must be repaired.Repairs must be made following consultation withthe third-party inspector. The type and location ofall repairs must be documented in the final diagramand their welding process and test log sheets kepton record. The third-party inspector must checkeach repair and verify that it is fully satisfactory.

6.8 Welding and Site TestingWelding and site testing must be done inaccordance with the DVS R 2225-4 Guidelines. Awelding trial using the welding machines andequipment, sensors and testing equipment intendedfor subsequent use must be conducted in thepresence of the third-party inspector before weldingwork begins or during construction of the field trialplot. Use of procedures, machines or equipmentother than those used in the trial is allowed onlywith the prior consent of the third-party inspector.

Normally only geomembranes made from the sameresin may be welded together. Should welding ofgeomembranes made from two different resins beunavoidable, the two resins must either be in thesame MFR group as defined in DIN 16776-1 or inthe MFR groups 006 and 012.

In addition to site testing, laboratory testing of short-term mechanical properties must be carried out bythe third-party inspector on at least 25 % of theseam samples made before welding or taken fromeither end of seams. The test procedures usedmust be in accordance with the DVS R 2226-3Guidelines; the results must be evaluated inaccordance with the DVS R 2226-1 Guidelines.

Only resins used in manufacturing of certifiedgeomembranes are permissible for use asextrudates. An acceptance test certificate based onDIN EN 10 204-2.3 is required for each shipment ofextrudate resin to the site. It must provide the QC

17

test results given in DVS M2211 determined by theextrudate manufacturer on this shipment. The testcertificate must be provided to the third-partyinspector along with the shipping papers.

6.9 Protective LayersA protective layer is required between thegeomembrane and the drainage layer (e.g. 16 –32 mm gravel). Its purpose is to protect thegeomembrane from puncture of any type duringconstruction and subsequent operation of thelandfill. The protective layer must be dimensionedto withstand the maximum load and temperatureexpected in operation. In addition, materials anddesign must be such that shear strength asrequired for static stability on slopes is not impairedby this loading.

Proof of suitability of protective layers withgeotextile components must be furnished by meansof a certification document in accordance with theBAM Guidelines entitled “Requirements forProtective Layers Over Geomembranes inComposite Liner Systems”. Geotextiles with lowerarea weights than those specified in Section 9 ofthese Certification Guidelines may be used in capliner systems providing their protection efficiencysatisfies the requirements of Section 5.3 of thecertification guidelines for protective layers.The installation contractor must normally place theprotective layer each day following completion ofthe liner surface which was fabricated andsmoothed out that day. The third-party inspectormust verify that the installation and anchoring

procedures for the protective and drainage layerswill cause no damage to the geomembrane below.Further requirements regarding protective layerinstallation are given in Section 10 of thecertification guidelines for protective layers.

7. Changes, Period of Validity andNotification of Deficiencies

Should any changes occur in the objects certified,i.e. the resin, geomembrane dimensions, surfacetexturing, identification markings, place ofmanufacture, installation processes and jointingtechnology used by installation contractors or theintended application field, a new or revisedcertification document is required.

Certifications are normally issued for an indefiniteperiod of time. BAM reserves the express right ofrevocation as described in Section 1.

Should manufacturing violate the requirements ofthe certification document or should transportand/or installation procedures not conform to theinstructions given on the state of the art, thecertification document is no longer valid. It thenmay not be used as proof of suitability of thegeomembranes in question. The third-partyinspector and/or approval authorities must report toBAM any repeated or serious deficiencies dis-covered in manufacture and installation of geo-membranes and any geomembrane-relatedfailures.

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8. Requirement Tables

Table 1, Part 1: General Physical Requirements

Properties Test Attributes Requirements Tests/Test Conditions1.1 Surface condition Appearance Smooth surface, free of

fissures, craters andpores, no damage

1.2 Homogeneity Appearance of crosssection

Free of pores, voids,foreign inclusions

Visual inspection inaccordance with DIN16726, Section 5.1

1.3 Carbon blackcontent

Weight percentage Range for nominal valuespecified in certificationreport: 1.8 – 2.6 wt %,individual valuesdetermined may not varyfrom nominal by more than±10 %

Thermogravimetricanalysis based on DIN ENISO 11358, Section B1 inSupplemental Informationon Tests1, or determinationin accordance with ASTM1603-94

1.4 Carbon blackdistribution

SupplementalInformation onTests1

Supplemental Informationon Tests1

ASTM D5596-94, SectionB2 in SupplementalInformation on Tests1

1.5 Skew Maximum distancebetween edge ofgeomembrane andstraight line over alength of 10 m whenrolled out over alength of 12 m

All individualmeasurements must be≤ 50 mm

1.6 Waviness Greatest clearancebetweengeomembrane andlevel supportingsurface over a lengthof 10 m when rolledout over a length of12 m

All individualmeasurements must be≤ 50 mm

Determination of skew andwaviness in accordancewith DIN 16726, Section5.2

Nominal thicknessand average thick-ness

Arithmetic average ofthickness measurementsmust be ≥ nominalthickness

1.7 Thickness

Individual thicknessmeasurements

The minimum permissiblethickness is 2.50 mm.Therefore, for geomem-branes with a nominalthickness of 2.50 mm allindividual measurementsmust be ≥ 2.50 mm andthe maximum permissibledeviation of any individualvalue from average is± 0.15 mm. For othernominal thicknesses,maximum permissibledeviation of any individualvalue from average is± 0.20 mm

As called for in DIN 16726Section 5.3, measurethickness in accordancewith DIN 53370 every0.2 m over the entire widthof the geomembrane.

1) The pamphlet entitled “Supplemental Information on Tests for Certification of Plastic Geomembranes forLandfill Liners“ is available from Laboratory IV.32, Landfill Engineering, BAM/Berlin.

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Table 1, Part 2 General Physical Requirements

Properties Test Attributes Requirements Tests/Test Conditions1.8 Melt flow rate MFR of resin,

MFR ofgeomembrane

MFR ≤ 15 %, MFR : absolute value ofdifference in MFR betweenresin and geomembrane

DIN ISO 1133

1.9 Dimensionalstability

Absolute value ofshrinkage δL ofsides of squaresample

δL ≤ 1.0 % for allindividual values

Oven curing and shrinkagedetermination based onDIN 16726, Section 5.13.1,DIN 53377 and draft DINEN 495-1, Oven cure at(120±2)° C for 1 hour,shrinkage determination1)

on 10 cm squarespecimens taken every1.0 m over the width of thegeomembrane. Measuringaccuracy of themechanical measuringgauge: at least 0.01 mm.Round off shrinkage valueto nearest 0.1 %.

Permeation rate oftrichloroethylene at23 °C

< 80 g/m²d, determinedfrom the steady-state line

1.10 Permeabilty tohydrocarbons

Permeation rate ofacetone at 23 °C

< 0.5 g/m²d, determinedfrom the steady-state line

Steady-state determinationat 23° C on specimenswith 80 mm effectivediameter and 2.5 mmthickness based on DIN53532, Section B4 ofSupplemental Informationon Tests1

1.11 Oxidative stability2 Oxidation InductionTime (OIT)

At 210 °C 20 min Determination based onDIN EN 728, Section B5 ofSupplemental Informationon Tests1


2) The efficiency of antioxidants depends on temperature. An antioxidant which is highly effective at normalambient temperatures may not be effective at the high temperatures used in the OIT procedure. This hasbeen taken into account in the requirements given under points 1.11 and 3.3. Depending on thestabilization formulation used as disclosed to BAM, in certain cases other analytic procedures arerequired to determine the change in stabilization caused by immersion testing.

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Table 2: Mechanical Requirements

Properties Test Attributes Requirements Tests/Test Conditions2.1 Behaviour under

multiaxialdeformation

Bulge elongation b inmultiaxial tensile test

b ≥ 15 %, without yielding Based on DIN 53861-1and ASTM D5617, seeSection B6 ofSupplemental Informationon Tests1

2.2 Tensile properties Yield strength YElongation at yield YElongation at breakB, in both extrusionand transversedirections

Y ≥ 15 N/mm2

Y ≥ 10 %,B ≥ 400 %,

Tensile test in accordancewith DIN EN ISO 527-3,test specimen type 5,(Specimen thickness neednot be in conformance withthis standard), 23° C /50% R.H., crossheadspeed 50 mm/min up to20% elongation, thereafter200 mm/min, 5 testspecimens for eachdirection (extrusion andtransverse) taken over theentire width of the geo-membrane

2.3 Tear resistance Tear force Tear force ≥ 500 N,

Tear force ≥ 300 N

Tear test in accordancewith DIN 53356-A,Tear test (Graves-typecrescent specimen) DIN53515, on specimenstaken in extrusion andtransverse directions

2.4 Resistance tostatic puncture

Puncture force ≥ 6000 N Static puncture test DINEN ISO 12236, crossheadspeed 50 mm/min

2.5 Resistance todynamic puncture

Water tightness atspot of puncture

No loss of water tightness Test in accordance withDIN 16726, Section 5.12,drop height 2000 mm

2.6 Cold temperaturebrittleness(flexural)

Visual appearance offlex edge

No cracks Flexural testing inaccordance with DIN EN1876-1, flex edge inextrusion and transversedirections

2.7 Relaxationbehaviour

Stress as a function oftime at constant strain(stress vs. time curve)

Stress at 1000 hours mustbe ≤ 50 % of stress at 1minute

Stress relaxation test inaccordance with DIN53441, 3 % strain, 23 °C,50 % R.H., specimenstaken in extrusion andtransverse directions

Deformation andfailure behaviourunder shear stress

No shear failure of seam,pronounced necking inparent material

Shear test according toDVS R 2226-2, crossheadspeed 50 mm/min

2.8 Seam quality

Deformation andfailure behaviourunder peel stress

No peeling of seam,pronounced necking inparent material

Peel test according to DVSR 2226-2, crossheadspeed 50 mm/min


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Table 3, Part 1: Requirements for Physical Resistance and Long-Term Behaviour

Nr. Properties Test Attributes Requirements Tests/Test Conditions3.1 Resistance to

chemicals(concentratedliquid solutions)1

Change in weight,change in yieldstrength andelongation at yield

Change in weight afterredrying ≤ 10 %Change in yield strengthand elongation at yield≤ 10 %

Immersion testing on thebasis of DIN ISO 175, seeSection B9 of Supple-mental Information onTests1. Immersiontemperature: 23 °C.Immersion must be over aperiod of 90 days or toattainment of steady-stateweight, whichever occursfirst. Tensile tests to beconducted on redriedspecimens.

3.2 Resistance tostress cracking

Time to failure instress crack test

≥ 200 h at test stress equalto 30 % of the yieldstrength determined at23 °C / 50 % R.H.

Notched constant tensileload test in accordancewith ASTM D 5397, seeSection B7 of Supple-mental Information onTests2

3.3 Resistance tothermal oxidativedegradation in air

Change in appear-ance, relative changein elongation at breakB, OIT time after 1/2year exposure:OIT(0.5 y)Relative change inOIT time:(OIT(0.5y)–OIT(1y))/OIT(0.5y)

No change, see Table 1.1

No change beyondexperimental uncertainty

Average time ≥ 10 min≤ 0.3 calculated fromaverage values

Oven curing in forced-convection oven at 80 °Cfor 1 year,

OIT determination basedon DIN EN 728 and ASTMD 3895 at 210 °C inaluminium pan

3.4 Long-termbehaviour undercombinedstressing3

Graph of time tofailure vs. test stress inlong-term pipe bursttesting

Extrapolation (in accor-dance with theextrapolation timelimitations given in DIN16887) of time to failure vs.stress curves generated athigh temperatures (e.g.80 °C, 60 °C) must predictno failure after 50 years ata stress of 4 N/mm2 and atemperature of 40 °C.

Long-term burst testing inaccordance with DIN 16887on pipe specimensextruded or otherwise fabri-cated from the resin usedto make the geomembrane

1) Substances 2, 3, 6, 7, 10 and 11 need not be tested for HDPE geomembranes, see “SupplementalInformation on Tests for Certification of Plastic Geomembranes for Landfill Liners“, which is available fromLaboratory IV.32, Landfill Engineering, BAM/Berlin.


3) Service life prediction of HDPE geomembranes is based on extrapolation of long-term pipe burst testcurves in accordance with DIN 16887 or ISO DIS 9080. The validity of this procedure is backed up byscientific studies and decades of experience. Pipe burst test curves are not required for resins forgeomembranes if their stress-crack resistance has been shown to fulfil the requirements of point 3.2above and their oxidative stability has been shown to fulfil the requirements of point 3.3 above in a testanalogous to DIN 16887 pipe burst testing – i.e. involving immersion of geomembrane specimens inwater at 80 °C for a period of at least 104 h (e.g. long-term tensile test).

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Table 3, Part 2: Requirements for Physical Resistance and Long-Term Behaviour

Properties Test Attributes Requirements Tests/Test Conditions3.6 Weathering

resistanceChange in mechanicalproperties

Section B10 ofSupplemental Informationon Tests1

Section B10 ofSupplemental Informationon Tests1

3.7 Microbe resistance Visual inspection,change in weight,change in mechanicalproperties

No substantial change inaverage values i.e.,w ≤ 5 %, , ≤ 10 %

DIN EN ISO 846,Procedure D, soil burialtesting in microbe-activesoil for 1 year,tensile testing in accor-dance with DIN ISO 527,see Table 2, 2.2

3.8 Root penetrationresistance

Visual inspection No penetration FLL root penetrationresistance procedure2,from FLL Guidelines forLandscaped Roofs, testson material with andwithout welding seams

3.9 Welding propertiesof resins3

Time to failure in long-term peel test

Geometric mean≥ 35 h

Long-term peel testingbased on DVS R 2203-4and DVS R 2226-3 ofoverlap welds with testchannels made with hot-wedge welding machineusing welding parametersin optimum field, seeSection B11 of Supple-mental Information onTests1


2) FLL: Landscaping Research Society, Bonn/Germany. The FLL test procedure is currently being revisedby CEN Technical Committee TC 254.

3) This time-to-failure requirement characterizes the welding properties of different resins. It is not suitablefor evaluation of the quality of a welding seam per se. Welding seams not fabricated in the optimumparameter field which do not show times to failure typical of that resin are substandard even if their timesto failure exceed 35 h.

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Table 4: Additional Requirements for Textured Geomembranes

Properties Test Attributes Requirements Tests/Test Conditions4.1 Thickness in

textured areasThickness The thinnest point in

the texturedgeomembrane must notbe below the specifiedminimum (2.50 mm, orfor thickergeomembranes,nominal minus 0.20mm)

Measurement e.g. inaccordance with ASTM D5994-96, see Section B3 ofSupplemental Information onTests1


Absolute value ofshrinkage δL ofsides of squaresample

δL ≤ 1.50 % forindividual values ofembossed texturing δL ≤ 1.00 % forindividual values ofapplied texturing

Table 1, 1.9

4.3 Mechanicalproperties oftextured areas

Elongation at break εB Requirement set foreach case individually

Table 2, 2.2

Nominal amount andvariation of texturingarea weight

Requirement set foreach case individually

Determination on a specificspecimen area (typically100 cm²)

Variation in frictionparameters

No substantial addit-ional variation in frictionparameters beyond testrepeatability

Shear-box testing of 30 cm x30 cm specimens inaccordance with GDA E 3-8

4.4 Texturinghomogeneity ofapplied texturing

Homogeneity oftexturing appearance

Comparison withreference samplesprovided to BAM

Visual inspection

Behaviour in shear-box test

No peel-off or removalof texturing

Shear-box testing undercompressive loads typical oflandfills in accordance withGDA E 3-8

Scrape strength Requirement set foreach case individually

Test procedure of MPADarmstadt, Section B13 ofSupplemental Information onTests1.

4.5 Texturing adhesionfor appliedtexturing

Time to failure in long-term shear test

Evaluation of time tofailure based on DIN16887

Long-term shear test, seeSupplemental Information onTests1

4.6 Chemicalresistance ofbonding oftexturing appliedafter production

Change in scrapestrength

Change in averagevalue ≤ 10 %

Immersion in substances 5and 9, see Table 3, 3.1. Forscrape test procedure, seeSection B12 of Supple-mental Information on Tests1

4.7 Stress-crackresistance (long-term tensile test)

Time to failure Geometric mean oftimes to failure 700 h

Long-term tensile test basedon DVS R2203-4 on at least 5test specimens at 80 °C und4 N/mm² tensile stress in a2 % surfactant solution, seeSection B8 of SupplementalInformation on Tests1


24

Table 5: Test Procedures and Frequencies for Incoming Quality Control of Resin and Carbon Black Batch

Test Attributes Tests / Test Specimens Frequency Requirements andTolerances

5.1 Density DIN 53479, Procedure A /extrudate from MFRdetermination of resin orbase polymer pellets

Random samplesfrom every shipment

Requirement defined incertification report

5.2 Melt index MFR190/5 or MFR190/21.6

DIN ISO 1133 / resin orbase polymer pellets



5.3 Weight percentcarbon black

Thermogravimetric analysisbased on DIN EN ISO11358 (see SupplementalInformation) ordetermination by ASTM1603-76 / batch pellets



< 0.10 wt %in precompounded resinor base polymer

5.4 Weight percentvolatiles, moisture

Weight loss in oven (DINEN 12099 and R 14.3.1 TW)or in infrared oven / resinpellets or base polymerpellets and batch pellets

Random samplesfrom every shipmentand before everyproduction start-up, orat least once perproduction week

< 0.25 wt % in batch

5.5 Bulk density1 DIN EN ISO 60 and DIN53466/ base polymer pelletsand batch pellets

Random samplesfrom every shipmentand before everyproduction start-up, orat least once perproduction week

Metering procedure andprocess set in qualitymanagement manual

1) Required only in the event volumetric batch metering is used.

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Table 6, Part 1: Test Procedures and Frequencies for In-House Quality Control of Geomembranes byManufacturer

Test Attribute Tests / TestSpecimens

Frequency Requirements andTolerances

6.1 Thickness Table 1, 1.7 /measured at aminimum of 10different pointsacross the width ofthe geomembrane

Continuous automaticmonitoring1 with mechanicalcontrol measurement every300 m

Requirement defined incertification report; rollcertificate must show atleast the minimum undmaximum values of controlmeasurement

6.2 Visual appearance Table 1, 1.1 Continuous Table 1, 1.1; roll certificatemust confirm satisfactoryappearance

6.3 Skew andwaviness

Table 1, 1.5 and 1.6 Per production start-up2 Table 1, 1.5 and 1.6; rollcertificate must confirm in-spec skew and waviness

6.4 Weight percentcarbon black5

Table 1, 1.3 Per production start-up andchange in batch lot3 and atleast every 900 m

Requirement defined incertification report; rollcertificate must give testprocedure and individualvalues obtained

6.5 Homogeneity ofcarbon blackdistribution5

Table 1, 1.4 Per production start-up andchange in batch lot3 and atleast every 900 m

Table 1, 1.4; roll certificatemust confirmhomogeneous distribution

6.6 Yield strength,Elongation at yield,Elongation atbreak

Table 2, 2.2;Crosshead speed:50 mm/min up to20% elongation,thereafter200 mm/min / Onetest specimen eachin extrusion andtransverse direc-tions from the edgeand the middle ofsmooth geomem-branes or from theland area of texturedgeomembranes4

Per production start-up andat least every 300 m

Requirement defined incertification report; rollcertificate must show theminimum und maximumvalues determined inextrusion and transversedirections

1) In production lines without continuous automatic thickness monitoring, thickness must be measured overthe entire production width every 10 m using an ultrasonic gauge.

2) Definition of production start-up: restart after machine stoppage or change of resin or thickness.3) A higher test frequency may be specified in individual cases after a production start-up or change of

batch lot.4) The certification report will specify the sampling procedure for test specimens from textured areas and

the criteria to be used in their evaluation.5) Only required when carbon black (batch) is added by the geomembrane manufacturer.

26

Table 6, Part 2: Test Procedures and Frequencies for In-House Quality Control of Geomembranes byManufacturer

Test Attributes Tests / TestSpecimens

Frequency Requirements andTolerances

6.7 Melt index andchange in meltindex

Table 1, 1.8 /samples from thegeomembrane andthe texturingmaterial


Requirement defined incertification report; rollcertificate must show theMFR determined in 5.2 ofTable 5 and difference toMFR of the resin


Table 1, 1.9 /specimens takenfrom the edges, themiddle of thegeomembrane andfrom other criticallocations (e.g.transition betweensmooth and texturedareas)


Table 1, 1.9; roll certificatemust show the individualvalues determined andtheir respective samplingpoints

6.9 Area weight oftexturing forapplied texturing

In-house procedure Per production start-up andat least every 300 m

Requirement set defined incertification report; rollcertificate must show theminimum und maximumvalues determined

6.10 Texturing adhesionfor appliedtexturing

In-house procedure Per production start-up andat least every 300 m

Requirement defined incertification report; rollcertificate must confirmsatisfactory adhesion

27

Table 7: Test Procedures and Frequencies for Third-Party Inspection of Resin, Carbon Black Batch andGeomembranes

Test Attributes Tests / Test Specimens Requirements andTolerances1

7.1 Density Table 5, 5.1 Set in certification report7.2 Melt index MFR 190/5

or MFR 190/21.6Table 5, 5.1 Set in certification report

7.3 Change in melt index Table 6, 6.7 Set in certification report

7.4 Thickness Table 6, 6.1 Set in certification report7.5 Visual appearance of

surface and cross-section

Table 1, 1.1 and 1.2 Table 1, 1.1 and 1.2

7.6 Visual appearance ofidentification markings

Visual inspection Section 2.5 and set in certification report

7.7 Weight percent carbonblack

Table 1, 1.3 / geomembrane Set in certification report

7.8 Homogeneity of carbonblack distribution

Table 1, 1.4 / geomembrane Table 1,1.4

7.9 Dimensional stability Table 6, 6.8 Table 1, 1.9 and Table 4, 4.27.10 Multiaxial bulge

elongationTable 2, 2.1 Table 2, 2.1

7.11 Yield strengthElongation at yieldElongation at break

Table 6, 6.6 Set in certification report

7.12 Static punctureresistance

Table 2, 2.4 Table 2, 2.4

7.13 Area weight of texturing(applied texturing only)

Table 6, 6.9 Table 6, 6.9

7.14 Adhesion of texturing(applied texturing only)

Table 4, 4.5 and Table 6, 6.10 Table 4, 4.5 and Table 6, 6.10

7.15 Oxidation inductiontime (OIT)

Based on DIN EN ISO 728, seeSupplementary Instructions

Table 1, 1.11; statistically significantcorrelation2 with specification for resin

7.16 Type and content oftracer

Set on case-by-case basis, testcarried out by BAM /geomembrane

Confidential, disclosed to BAM

1) In general, the requirements specified in the requirement tables must be fulfilled. Additional requirementsand tolerances characterizing the particular properties of the specific geomembrane certified are given inAppendix 1 of the certification document.


.

28

9. Standards, Guidelines, Official Gazettes und RecommendationsDIN EN ISO 60(draft) 1999-01 Plastics – Determination of apparent density of material that can be

poured from a specified funnel

DIN ISO 175 1989-04 Plastics – Methods of test for the determination of the effects ofimmersion in liquid chemicals

DIN EN 495-1 (draft) 1991-12 Thermoplastic and elastomeric roofing and sealing sheets;Determination of high temperature dimensional stability

DIN EN ISO 527-1 1996-04 Plastics – Determination of tensile properties - Part 1: Generalprinciples

DIN EN ISO 527-3 1995-10 Plastics – Determination of tensile properties - Part 3: Test conditionsfor films and sheets

DIN EN 728 1997-03 Plastics piping and ducting systems - Polyolefin pipes and fittings –Determination of oxidation induction time

DIN EN ISO 846 1997-10 Plastics – Evaluation of the action of microorganisms

DIN ISO 1133 1993-02 Plastics – Determination of the melt mass-flow rate (MFR) and themelt volume-flow rate (MVR) of thermoplastics

DIN EN 1876-1 1998-01 Rubber or plastics coated fabrics - Low temperatures tests - Part 1:Bending test

DIN 4062 1978-09Cold processable plastic jointing materials for sewer drains; jointingmaterials for prefabricated parts of concrete; requirements, testing andprocessing

DIN EN ISO 9000 2000 Quality management systems - Fundamentals and vocabulary

DIN EN ISO 9001 1994-08 Quality systems - Model for quality assurance in design, development,production, installation and servicing

DIN EN ISO 9002 1994-08 Quality systems -- Model for quality assurance in production,installation and servicing

DIN EN ISO 9003 1994-08 Quality systems - Model for quality assurance in final inspection andtest

DIN EN ISO 9004-1 1994-08 Quality management and quality system elements -- Part 1:Guidelines

DIN EN 10204 1995-08 Metallic products - Types of inspection documents (includesAmendment A1:1995

DIN EN ISO 11358 1997-11 Plastics – Thermogravimetry (TG) of polymers -- General principles

DIN EN 12099 1997-08 Plastics piping systems - Polyethylene piping materials andcomponents - Determination of volatile content

DIN EN ISO 12236 1996-04 Geotextiles and geotextile-related products -- Static puncture test(CBR test)

DIN 16726 1986-12 Plastic roofing sheets and plastic sheets for waterproofing; testingDIN 16776-1 1984-12 Plastic moulding materials; polyethylene and ethylene copolymers

DIN 16887 1990-07 Determination of the long-term hydrostatic pressure resistance ofthermoplastics pipes

DIN 18200 1986-12 Control (Quality control) of construction materials, constructioncomponents and construction designs; general principles

DIN 18200(draft) 1998-12 Assessment of conformity for construction products - Certification of

construction products by certification body

DIN EN ISO 17025 1999-05 General requirements for the competence of testing and calibrationlaboratories

DIN 53370 1976-02 Testing of plastic films; determination of the thickness by mechanicalfeeling

DIN 53377 1969-05 Testing of Plastic Films; Determination of Dimensional StabilityDIN 53356 1982-08 Testing of artificial leather and similar sheet materials; tear growth testDIN 53441 1984-01 Testing of plastics; stress relaxation testDIN 53479 1976-07 Testing of Plastics and Elastomers; Determination of Density

29

Standards, Guidelines, Official Gazettes und Recommendations (Continued)

DIN 53532 1989-06 Testing of elastomers; Determination of permeability of elastomer-sheetings to liquids

DIN 53861-1 1992-11 Testing of textiles; vaulting test and bursting test, tabels for theevaluation of tests

DIN 55350-11 1995-08 Concepts in quality and statistics; basic concepts in qualitymanagement, quality control and quality assurance

ISO DIS 9080Thermoplastic pipes for the transport of fluids – Methods ofextrapolation of hydrostatic stress rupture data to determine the long-term hydrostatic strength of thermoplastics pipe materials

ASTM D1603-94 1994 Standard Test Method for Carbon Black In Olefin Plastics

ASTM D3895-97 Standard Test Method for Oxidative-Induction Time of Polyolefins byDifferential Scanning Calorimetry

ASTM D5397-95 1995 Standard Test Method for Evaluation of Stress Crack Resistance ofPolyolefin Geomembranes Using Notched Constant Tensile Load Test

ASTM D5617-94 1994 Standard Test Method for Multi-Axial Tension Test of Geosynthetics

ASTM D5596-94 1994 Standard Test Method for Microscopic Evaluation of the Dispersion ofCarbon Black in Polyolefin Geosynthetics

ASTM D5994-96 1996 Standard Test Method for Measuring Core Thickness of TexturedGeomembrane

DVS R 2203-4 7/1997 Testing of Welded Joints of Thermoplastics Plates and Tubes -Tensible Creep Test

DVS M 2211 11/1979 Welding Extrudates for Thermoplastics; Area of Validity,Nomenclature, Requirements, Testing

DVS R 2225-4 7/1997 Joining of Lining Membranes Made of Polyethylene in lining of landfilland contaminated sites

DVS R 2226-1preliminary version 8/1998 Testing of Fused Joints on Liners Made of Polymer Materials - Testing

Procedure, Requirements

DVS R 2226-2 7/1997 Testing of Fused Joints on Liners Made of Polymer Materials - LabShear Test

DVS R 2226-3 7/1997 Test of Fusion on PE Liners – Peeling TestGDA E 2-7 1998 Shear Resistance of Lining Systems

GDA E 2-21 1997 Calculation of Spreading Stability and Estimated Deformation onLandfill Bases

GDA E 3-8 1997 Frictional Behaviour of Geosynthetics

GDA E 7-1 1997 Static Stability Calculations of Geosynthetic Reinforcing Componentsin Landfills

SupplementalInformation on Tests 1999

Supplemental Information on Tests for Certification of PlasticGeomembranes for Landfill Liners, Laboratory IV.32, LandfillEngineering, BAM/Berlin.

FLL Guidelines forLandscaped Roofs 1995 Guidelines for planning, construction and maintenance of landscaped

roofs

R 14.3.1 TW 1998-01 PE 80 and PE 100 Pressure Pipe for Drinking Water Applications,Gütegemeinschaft Kunststoffrohre e.V., Bonn

30

10. Appendices to Certification Report, Numerical Codes for FederalStates and Test InstitutesAppendices to Certification Report

Appendix 1: Requirements and tolerances for in-house QC and third-party inspectionAppendix 2: Designation of manufacturer with production plants and installation contractorsAppendix 3: Description of manufacturing processAppendix 4: Materials declaration of manufacturer (type of resin, percent carbon black, use of recycle

material)Appendix 5: Description of identification markings and their configurationAppendix 6: Description of positions of identification markings on geomembranesAppendix 7: Description of quality assurance measures

a) in-house quality controlb) third-party inspection

Appendix 8: Manufacturer’s storage and transport instructionsAppendix 9: Description of roll identification labelsAppendix 10: Description of texturing type(s) of geomembranes

Numerical Codes for Federal States

(In accordance with Federal Worksheet 4/91, page 61):Baden-Württemberg 01 Lower Saxony 07Bavaria 02 North Rhine-Westphalia 08Berlin 03 Rheinland-Pfalz 09Brandenburg 12 Saarland 10Bremen 04 Saxony 14Hamburg 05 Saxony-Anhalt 15Hessen 06 Schleswig-Holstein 11Mecklenburg-Vorpommern 13 Thuringia 16

Institutes for Suitability Testing and Third-Party Inspection of Manufacturing:

Süddeutsches Kunststoff-Zentrum,Officially Approved Plastics Testing InstituteHerr GlückFrankfurter Straße 15-17 Tel: 0931 4104-0, Fax: 0931 4104-177,D-97082 Würzburg e-mail: [email protected]

State Materials Testing Institute of Darmstadt,Plastics DepartmentHerr HeimerGrafenstr.2 Tel: 06151 16-2042, Fax: 06151 16-5658,D-64283 Darmstadt e-mail: [email protected]

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