1、Designation:D698209Standard Practice forDetecting Hot Spots Using Point-Net(Grid)Search Patterns1This standard is issued under the fixed designation D6982;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A nu
2、mber 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 provides equations and nomographs,and areference to a computer program,for calculating probabilitiesof detecting hot spots(that
3、 is,localized areas of soil orgroundwater contamination)using point-net(that is,grid)search patterns.Hot spots,more generally referred to as targets,are presumed to be invisible on the ground surface.Hot spotsmay include former surface impoundments and waste disposalpits,as well as contaminant plume
4、s in ground water or thevadose zone.1.2 For purposes of calculating detection probabilities,hotspots or buried contaminants are presumed to be ellipticallyshaped when projected vertically to the ground surface,andsearch patterns are square,rectangular,or rhombic.Assump-tions about the size and shape
5、 of suspected hot spots are theprimary limitations of this practice,and must be judged byhistorical information.A further limitation is that hot spotboundaries are usually not clear and distinct.1.3 In general,this practice should not be used in lieu ofsurface geophysical methods for detecting burie
6、d objects,including underground utilities,where such buried objects canbe detected by these methods(see Guide D6429).1.4 Search sampling would normally be conducted duringpreliminary investigations of hazardous waste sites or hazard-ous waste management facilities(see Guide D5730).Samplingmay be con
7、ducted by drilling or by direct-push methods.Incontrast,guidance on sampling for the purpose of makingstatistical inferences about population characteristics(forexample,contaminant concentrations)can be found in GuideD6311.1.5 This standard does not purport to address all of thesafety concerns,if an
8、y,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:2D5730 Guide for Site Characterization for Environment
9、alPurposes With Emphasis on Soil,Rock,the Vadose Zoneand Groundwater(Withdrawn 2013)3D6051 Guide for Composite Sampling and Field Subsam-pling for Environmental Waste Management ActivitiesD6311 Guide for Generation of Environmental Data Relatedto Waste Management Activities:Selection and Optimiza-ti
10、on of Sampling DesignD6429 Guide for Selecting Surface Geophysical Methods3.Terminology3.1 Definitions:3.1.1 hot spota localized area of soil or groundwatercontamination.3.1.1.1 DiscussionA hot spot may be considered as adiscrete volume of buried waste or contaminated soil where theconcentration of
11、a contaminant of interest exceeds someprespecified threshold value.Although hot spots are morelikely to have variable sizes and shapes and not have clear anddistinct boundaries,ellipitically shaped hot spots or targetswith well defined edges are assumed for the purposes ofcalculating detection proba
12、bilities.The assumption that hotspots have elliptical shapes is not inconsistent with knownhistorical patterns of contaminant distribution.3.1.2 sampling densitythe number of soil borings(that is,sampling points)per unit area.3.1.3 semi-major axis,aone-half the length of the longaxis of an ellipse.F
13、or a circle,this distance is simply theradius.3.1.4 semi-minor axis,bone-half the length of the shortaxis of an ellipse.3.1.5 targetthe object or“hot spot”that is being searchedfor.1This practice is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of S
14、ubcommittee D34.01.01 onPlanning for Sampling.Current edition approved Nov.15,2009.Published December 2009.Originallyapproved in 2003.Last previous edition approved in 2003 as D698203.DOI:10.1520/D6982-09.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Serv
15、ice at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohoc
16、ken,PA 19428-2959.United States1 3.1.6 threshold concentrationthe concentration of a con-taminant above which a hot spot is considered to be detected.3.1.7 unit cellthe smallest area into which a grid can bedivided so that these areas have the same shape,size andorientation.For a triangular grid,the unit cell is a 60/120rhombus comprised of two equilateral triangles with a commonside.3.2 Symbols:a=length of the semi-major axis of an ellipseb=length of the semi-minor axis of an ellipseAT=area of
