ASTM_D_6747_-_15.pdf

Designation:D674715Standard Guide forSelection of Techniques for Electrical Leak Location ofLeaks in Geomembranes1This standard is issued under the fixed designation D6747;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 guide is intended to assist individuals or groups inassessing different options available for locating leaks ininstalled geomembranes using electrical methods.For clarity,this guide uses the term“leak”to mean holes,punctures,tears,knife cuts,seam defects,cracks,and similar breaches in aninstalled geomembrane(as defined in 3.2.3).1.2 This guide does not cover systems that are restricted toseam testing only,nor does it cover systems that may detectleaks non-electrically.It does not cover systems that onlydetect the presence,but not the location of leaks.1.3(WarningThe electrical methods used for geomem-brane leak location could use high voltages,resulting in thepotential for electrical shock or electrocution.This hazardmight be increased because operations might be conducted inor near water.In particular,a high voltage could exist betweenthe water or earth material and earth ground,or any groundedconductor.These procedures are potentially very dangerous,and can result in personal injury or death.The electricalmethods used for geomembrane leak location should beattempted only by qualified and experienced personnel.Appro-priate safety measures must be taken to protect the leaklocation operators as well as other people at the site.)1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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 requirements prior to use.2.Referenced Documents2.1 ASTM Standards:2D4439 Terminology for GeosyntheticsD7002 Practice for Electrical Leak Location on ExposedGeomembranes Using the Water Puddle MethodD7007 Practices for Electrical Methods for Locating Leaksin Geomembranes Covered with Water or Earthen Mate-rialsD7240 Practice for Leak Location using Geomembraneswith an Insulating Layer in Intimate Contact with aConductive Layer via Electrical Capacitance Technique(Conductive Geomembrane Spark Test)D7703 Practice for Electrical Leak Location on ExposedGeomembranes Using the Water Lance MethodD7953 Practice for Electrical Leak Location on ExposedGeomembranes Using the Arc Testing Method3.Terminology3.1 For general definitions used in this guide,refer toTerminology D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 conductive-backed geomembrane,na specialtygeomembrane manufactured using the coextrusion processwith an insulating layer in intimate contact with a conductivelayer.3.2.2 electrical leak location,na method which useselectrical current or electrical potential to locate leaks in ageomembrane.3.2.3 leak,nfor the purposes of this guide,a leak is anyunintended opening,perforation,breach,slit,tear,puncture,crack,or seam breach.Significant amounts of liquids or solidsmay or may not flow through a leak.Scratches,gouges,dents,or other aberrations that do not completely penetrate thegeomembrane are not considered to be leaks.Types of leaks1This guide is under the jurisdiction ofASTM Committee D35 on Geosyntheticsand is the direct responsibility of Subcommittee D35.10 on Geomembranes.Current edition approved Jan.1,2015.Published January 2015.Originallyapproved in 2002.Last previous edition approved in 2012 as D674712.DOI:10.1520/D6747-15.2For 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 detected during surveys include,but are not limited to:burns,circular holes,linear cuts,seam defects,tears,punctures,andmaterial defects.3.2.4 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 be likely detected.3.2.5 poor contact condition,nfor the purposes of thisguide,a poor contact condition means that a leak is not inintimate contact with the sufficiently conductive layer above orunderneath the geomembrane to be tested.This occurs on awrinkle or wave,under the overlap flap of a fusion weld,in anarea of liner bridging and in an area where there is a s