ASTM_D_7953_-_14.pdf

Designation:D795314Standard Practice forElectrical Leak Location on Exposed Geomembranes Usingthe Arc Testing Method1This standard is issued under the fixed designation D7953;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice is a performance-based standard for anelectrical method for locating leaks in exposed geomembranes.For clarity,this practice uses the term“leak”to mean holes,punctures,tears,knife cuts,seam defects,cracks,and similarbreaches in an installed geomembrane(as defined in 3.2.4).1.2 This practice can be used for geomembranes installed inbasins,ponds,tanks,ore and waste pads,landfill cells,landfillcaps,canals,and other containment facilities.It is applicablefor geomembranes made of materials such as polyethylene,polypropylene,polyvinylchloride,chlorosulfonatedpolyethylene,bituminous geomembrane,and any other electri-cally insulating materials.This practice is best applicable forlocating geomembrane leaks where the proper preparationshave been made during the construction of the facility.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D4439 Terminology for GeosyntheticsD6747 Guide for Selection of Techniques for ElectricalDetection of Leaks in GeomembranesD7002 Practice for Leak Location on Exposed Geomem-branes Using the Water Puddle SystemD7703 Practice for Electrical Leak Location on ExposedGeomembranes Using the Water Lance System3.Terminology3.1 Definitions:3.1.1 For general definitions used in this practice,refer toTerminology D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 conductive-backed geomembrane,na specialtygeomembrane manufactured using coextrusion technology fea-turing an insulating layer in intimate contact with a conductivelayer.3.2.2 current,nthe flow of electricity or the flow ofelectric charge.3.2.3 electrical leak location,na method which useselectrical current or electrical potential to locate leaks in ageomembrane.3.2.4 leak,nfor the purposes of this document,a leak isany unintended opening,perforation,breach,slit,tear,puncture,crack,or seam breach.Significant amounts of liquidsor solids may or may not flow through a leak.Scratches,gouges,dents,or other aberrations that do not completelypenetrate the geomembrane are not considered to be leaks.Types of leaks detected during surveys include but are notlimited to;burns,circular holes,linear cuts,seam defects,tears,punctures and material defects.3.2.5 leak detection sensitivity,nthe smallest leak that theleak location equipment and survey methodology are capableof detecting under a given set of conditions.The leak detectionsensitivity specification is usually stated as a diameter of thesmallest leak that can likely be detected.3.2.6 poor contact condition,nfor the purposes of thisdocument,a poor contact condition means that a leak is not inintimate contact with the conductive layer above or underneaththe geomembrane to be tested.This occurs on a wrinkle orwave,under the overlap flap of a fusion weld,in an area ofliner bridging and in an area where there is a subgradedepression or rut.3.2.7 probe,nfor the purposes of this document,anyconductive rod or conductive brush that is attached to a powersource to initiate the arc test.1This practice is under the jurisdiction of ASTM Committee D35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.10 on Geomembranes.Current edition approved July 1,2014.Published July 2014.DOI:10.1520/D795314.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Significance and Use4.1 Geomembranes are used as barriers to prevent liquidsfrom leaking from landfills,ponds,and other containments.Forthis purpose,it is desirable that the geomembrane have as littleleakage as practical.4.2 The liquids may contain contaminants that if releasedcan cause damage to the environment.Leaking liquids canerode the subgrade,causing further damage.Leakage can resultin product loss or otherwise prevent the installation fromperforming its intended containment purpose.4.3 Geomembranes are often assembled in the field,eitherby unrolling and welding p