1、Designation: D7648 12D7648/D7648M 18Standard Practice forActive Soil Gas Sampling for Direct Push or Manual-DrivenHand-Sampling Equipment1This standard is issued under the fixed designation D7648;D7648/D7648M; the number immediately following the designation indicatesthe year of original adoption or
2、, in the case of revision, 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 Scope*1.1 This practice details the collection of active soil gas samples using a
3、variety of sample collection techniques with toolingassociated with direct push drilling technology (DPT) (DP) or manual-driven hand-sampling equipment, for the express purposeof conducting soil gas surveys.1.2 This practice proceeds on the premise that soil gas surveys are primarily used for two (2
4、) purposes,purposes: 1)1) as apreliminary site investigative tool and 2)2) for the monitoring of ongoing remediation activities.activities (D7663).1.3 The practicality of field use demands that soil gas surveys are relatively accurate, as well as being simple, quick, andinexpensive. This guide sugge
5、sts that the objective of soil gas surveys is linked to three factors:1.3.1 VOC detection and quantitation, including determination of depth of VOC contamination.1.3.2 Sample retrieval ease and time.1.3.3 Cost.1.4 This practice will likely may increase the awareness of a fundamental difference betwe
6、en soil gas sampling for the purposeof soil gas surveys versus sub-slab or vapor intrusion investigations or both. Specifically, the purpose of a soil gas survey is toprovide quick and inexpensive data to the investigator that will allow the investigator to 1) develop a site investigation plan thati
7、s strategic in its efforts, 2) determine success or progress of on-going remedial activities, or 3) select the most suitable subsequentinvestigation equipment, or combinations thereof. On the other hand, the objective of soil gas sampling for sub-slab and vaporintrusion investigations (1,2,3, etc.)
8、is not preliminary, but rather the end result of the site investigation or long-term precisemonitoring. As such, stringent sampling methods and protocol are necessary for precise samples and data collection.1.5 Details included in this practice include a broad spectrum of practices and applications
9、of soil gas surveys, including:1.5.1 Sample recovery and handling,1.5.2 Sample analysis,1.5.3 Data interpretation, and1.5.4 Data reporting.1.6 UnitsThe values stated in either SI units or Inch-pound units given in brackets are to be regarded separately as standard.The values stated in each system ma
10、y not be exact equivalents; therefore, each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard.1.7 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in
11、PracticeD6026.1.7.1 The procedures used to specify how data are collected/recorded and calculated in the standard are regarded as the industrystandard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do notconsider material variat
12、ion, purpose for obtaining the data, special purpose studies, or any consideration for the users objectives;and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations.It is beyond the scope of this standard to consider significant
13、 digits used in analysis methods for engineering data.1.8 This practice suggestsoffers a variety of approaches useful to conducting successful soil gas surveys but set of instructionsfor performing one or more specific operations. This standard cannot replace education or experience and should be us
14、ed inconjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This ASTM1 This practice is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and VadoseZone Invest
15、igations.Current edition approved March 1, 2012Dec. 1, 2018. Published April 2012December 2018. Originally approved in 2012. Last previous edition approved in 2012 asD7648 12. DOI: 10.1520/D7648-12.10.1520/D7648_D7648M-18.This document is not an ASTM standard and is intended only to provide the user
16、 of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as
17、published by ASTM is to be considered the official document.*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 States1standard is not intended to represent or replace the standard
18、 of care by which the adequacy of a given professional service mustbe judged, nor should this document be applied without consideration of a projectsprojects many unique aspects. The word“Standard” in the title of this document means only that the document has been approved through the ASTM consensu
19、s process.1.7 This practice offers an organized collection of information or a series of options and does not recommend a specific courseof action. The success of any one soil gas survey methodology is strongly dependent upon the environment in which it is applied.1.9 This practice is not to be used
20、 for long term monitoring of contaminated sites or for site closure conformation.confirmation.1.10 This practice is not to be used for passive determination of flow patterns at contaminated sites.1.11 This practicestandard does not purport to address all of the safety concerns, if any, associated wi
21、th its use. It is theresponsibility of the user of this practicestandard to establish appropriate safety safety, health, and healthenvironmental practicesand determine the applicability of regulatory limitations prior to use.1.12 This practice does not purport to set standard levels of acceptable ri
22、sk. Use of this practice for purposes of risk assessmentis wholly the responsibility of the user.1.13 Concerns of practitioner liability or protection from or release from such liability, or both, are not addressed by thispractice.1.14 This international standard was developed in accordance with int
23、ernationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D653
24、Terminology Relating to Soil, Rock, and Contained FluidsD1356 Terminology Relating to Sampling and Analysis of AtmospheresD1357 Practice for Planning the Sampling of the Ambient AtmosphereD1452 Practice for Soil Exploration and Sampling by Auger BoringsD3249 Practice for General Ambient Air Analyzer
25、 ProceduresD3614 Guide for Laboratories Engaged in Sampling and Analysis of Atmospheres and EmissionsD3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD5314 Guide for Soil Gas Monitoring in the Vado
26、se Zone (Withdrawn 2015)3D6026 Practice for Using Significant Digits in Geotechnical DataD6196 Practice for Choosing Sorbents, Sampling Parameters and Thermal Desorption Analytical Conditions for MonitoringVolatile Organic Chemicals in AirD7663 Practice for Active Soil Gas Sampling in the Vadose Zon
27、e for Vapor Intrusion Evaluations2.2 EPA Standards:5EPA Method TO-15 Determination Of Volatile Organic Compounds (VOCs) In Air Collected In Specially-Prepared CanistersAnd Analyzed By Gas Chromatography/ Mass Spectrometry (GC/MS)EPAMethod TO-17 Determination of Volatile Organic Compounds inAmbientAi
28、r UsingActive Sampling Onto Sorbent Tubes3. Terminology3.1 For definitions of common technical terms used in this standard, refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 active sampling, nin vadose zone, a means of collecting an airborne or emission substance tha
29、t employs a mechanicaldevice such as a pump or vacuum assisted critical orifice to draw air or emissions onto or through the sampling device.3.2.2 capillary fringe, nin vadose zone, the basal region of the vadose zone comprising sediments that are saturated, or nearlysaturated, near the water table,
30、 gradually decreasing in water content with increasing elevation above the water table. Also seeTerminology D653.3.1.3 contaminant, na material added by human or natural activities which may, in sufficient concentrations, render theatmosphere unacceptable.3.1.4 emplacement, nthe establishment of con
31、taminant residence in the vadose zone in a particular phase.3.1.5 free product, nliquid phase contaminants released into the environment.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume in
32、formation, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.D7648/D7648M 1823.2.3 free vapor phase, nin vadose zone, a condition of contaminant residence in which volatilized contaminants occur inpo
33、rosity that is effective to free and open gaseous flow and exchange, such porosity generally being macroporosity.3.2.4 hot spot, nin vadose zone, areas where contaminants exceed cleanup standards or the highest level at a contaminatedsite.3.1.8 liquid phase, ncontaminant residing as a liquid in vado
34、se zone pore space, often referred to as “free product.”3.2.5 partitioning, nin vadose zone, the act of movement of contaminants from one soil residence phase to another.3.1.10 semivolatile organic compound (SVOC), nan organic compound with a saturated vapor pressure between 10-2kPa and10-8 kPa at 2
35、6 C.3.2.6 soil gas, nin vadose zone, vadose zone atmosphere.3.1.12 solute phase, na condition of contaminant residence in which contaminants are dissolved in ground water in either thesaturated or the vadose zone.3.1.13 sorbed phase, na condition of contaminant residence in which contaminants are ad
36、sorbed onto the surface of soilparticles or absorbed by soil organic matter.3.1.14 sorbent, na solid or liquid medium in or upon which materials are collected by absorption, adsorption, orchemisorption.3.1.15 sorption, na process by which one material (the sorbent) takes up and retains another mater
37、ial (the sorbate) byprocesses of absorption, adsorption, or chemisorption.3.1.16 vadose zone, nthe hydrogeological region extending from the soil surface to the top of the principal water table.3.2.7 volatile organic compound (VOC), nan organic compound with a saturation vapor pressure greater than
38、10-2kPa at 26C.boiling points typically ranging from a lower limit between 50C and 100C, and an upper limit between 240C and 260C,where the upper limits represent mostly polar compounds.4. Summary of Guide4.1 Sampling of soil gases (volatile contaminantscompounds such as methane and carbon dioxide,
39、which are indicators ofincreased microbial activity resulting from organic contaminants) in the vadose zone is an industry-accepted method used todirectly measure characteristics of the soil atmosphere. Characteristics determined from soil gas sampling are frequently used asindirect indicators of pr
40、ocesses occurring in and below a sampling horizon, including the presence, composition, origin anddistribution of contaminants in and below the vadose zone.4.2 Previously,Originally, soil gas sampling was used more as a tool for laying the groundwork for further soil exploration. Theability to quick
41、ly, accurately, and inexpensively determine VOCs,VOCs presence, levels, and depths have allowed this method tobecome a standard practice for preliminary site investigation as well as for monitoring the success of on-going site remediationefforts. Currently soil gas sampling has been gaining acceptan
42、ce as a reasonable method for the determination of risk assessmentof contaminated sites, known as soil gas investigations. This new direction in soil Soil gas sampling is now playing a major rolein the development of new methodologies with a current trend towards more stringent soil gas sampling met
43、hods and protocols.4.3 However, the practicality of field use demands that there is a soil gas sampling method that is accurate as well as simple,quick, and inexpensive, for the purposes of preliminary site investigation and the monitoring of on-going remediation efforts. Thisguidepractice refers to
44、 this method as a soil gas survey.4.4 The objective of a soil gas survey is to determine, through relative data, the highest level of contamination at a site (hotspot). Data collected from soil gas surveys provides information useful for the development of strategic and cost effective siteinvestigat
45、ion plans.4.5 The leading principle behind this guide is that there is a difference between soil gas surveys and soil gas investigations(1,2,3).4.5 While the need for stringent methodology is strongly supported for soil gas investigations, (sub-slab and vapor intrusioninvestigations) those same stri
46、ngent methods and protocols, when used for the purpose of soil gas surveying, are not cost effectivenor time efficient.4.6 Soil gas surveys need to be more use quick, time efficient, and cost effective than soil gas investigation methods. Theeconomic limits coupled with the objective of a soil gas s
47、urvey must be the leading factor behind the development of soil gassurvey methodology and protocol. If it takes as much time or much moneycost to survey as to investigate, then investigators willnot utilize this tool/practice.4.7 Vadose zone sampling methods have a set of procedures, both general an
48、d specific, that must be consistently followed inorder to provide maximum data quality and usefulness. Soil gas surveys are no exception, with have the primary procedurescommon to allmost soil gas sampling techniques. The procedures include:(1) Planning and preparation,D7648/D7648M 183(2) The act of
49、 sampling soil gas in the field,(3) Handling and transporting the sample, and(4) This method does not recommend a sample analysis, interpretation of the results of analysis, nor specific format for thepreparation of a report of findings. Instead it indicates minimum information to be included in a report of findings.4.7.1 The planning and preparation step begins with the formulation of project objectives, including purpose of the survey,appropriate application of the data to be collected and data quality objectives.4.7.2 Actual field work consists of
