1、Designation:D7648/D7648M18Standard Practice forActive Soil Gas Sampling for Direct Push or Manual-DrivenHand-Sampling Equipment1This standard is issued under the fixed designation D7648/D7648M;the number immediately following the designation indicates theyear of original adoption or,in the case of r
2、evision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice details the collection of active soil gassamples using a variety of sample collection te
3、chniques withtooling associated with direct push drilling(DP)or manual-driven hand-sampling equipment,for the express purpose ofconducting soil gas surveys.1.2 This practice proceeds on the premise that soil gassurveys are primarily used for two(2)purposes:1)as apreliminary site investigative tool a
4、nd 2)for the monitoring ofongoing remediation activities(D7663).1.3 The practicality of field use demands that soil gassurveys are relatively accurate,as well as being simple,quick,and inexpensive.This guide suggests that the objective of soilgas surveys is linked to three factors:1.3.1 VOC detectio
5、n and quantitation,including determina-tion of depth of VOC contamination.1.3.2 Sample retrieval ease and time.1.3.3 Cost.1.4 This practice may increase the awareness of a funda-mental difference between soil gas sampling for the purpose ofsoil gas surveys versus sub-slab or vapor intrusion investig
6、a-tions or both.Specifically,the purpose of a soil gas survey is toprovide quick and inexpensive data to the investigator that willallow the investigator to 1)develop a site investigation planthat is strategic in its efforts,2)determine success or progressof on-going remedial activities,or 3)select
7、the most suitablesubsequent investigation equipment,or combinations thereof.On the other hand,the objective of soil gas sampling forsub-slab and vapor intrusion investigations is not preliminary,but rather the end result of the site investigation or long-termprecise monitoring.As such,stringent samp
8、ling methods andprotocol are necessary for precise samples and data collection.1.5 Details included in this practice include a broad spec-trum of practices and applications of soil gas surveys,includ-ing:1.5.1 Sample recovery and handling,1.5.2 Sample analysis,1.5.3 Data interpretation,and1.5.4 Data
9、 reporting.1.6 UnitsThe values stated in either SI units or Inch-pound units given in brackets are to be regarded separately asstandard.The values stated in each system may not be exactequivalents;therefore,each system shall be used independentlyof the other.Combining values from the two systems may
10、result in non-conformance with the standard.1.7 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.7.1 The procedures used to specify how data are collected/recorded and calculated in the standard are regarded as thein
11、dustry standard.In addition,they are representative of thesignificant digits that generally should be retained.The proce-dures used do not consider material variation,purpose forobtaining the data,special purpose studies,or any consider-ation for the users objectives;and it is common practice toincr
12、ease or reduce significant digits of reported data to becommensurate with these considerations.It is beyond the scopeof this standard to consider significant digits used in analysismethods for engineering data.1.8 This practice offers a set of instructions for performingone or more specific operatio
13、ns.This standard cannot replaceeducation or experience and should be used in conjunction withprofessional judgment.Not all aspects of this practice may beapplicable in all circumstances.This ASTM standard is notintended to represent or replace the standard of care by whichthe adequacy of a given pro
14、fessional service must be judged,nor should this document be applied without consideration ofa projects many unique aspects.The word“Standard”in thetitle of this document means only that the document has beenapproved through the ASTM consensus process.1.9 This practice is not to be used for long ter
15、m monitoringof contaminated sites or for site closure confirmation.1.10 This practice is not to be used for passive determina-tion of flow patterns at contaminated sites.1.11 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the1This practice is
16、 under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.21 on Groundwater andVadose Zone Investigations.Current edition approved Dec.1,2018.Published December 2018.Originallyapproved in 2012.Last previous edition approved in 2012 as D7648 12.DOI:10.1520/D7648_D7648M-18.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United Stat
