ASTM_D_6250_-_98_2009.pdf

Designation:D625098(Reapproved 2009)Standard Practice forDerivation of Decision Point and Confidence Limit forStatistical Testing of Mean Concentration in WasteManagement Decisions1This standard is issued under the fixed designation D6250;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 covers a logical basis for the derivation ofa decision point and confidence limit when mean concentrationis used for making environmental waste management deci-sions.The determination of a decision point or confidence limitshould be made in the context of the defined problem.Themain focus of this practice is on the determination of a decisionpoint.1.2 In environmental management decisions,the derivationof a decision point allows a direct comparison of a samplemean against this decision point,where similar decisions canbe made by comparing a confidence limit against a concentra-tion limit(for example,a regulatory limit,which will be usedas a surrogate term for any concentration limit throughout thispractice).This practice focuses on making environmentaldecisions using this kind of statistical comparison.Otherfactors,such as any qualitative information that may beimportant to decision-making,are not considered here.1.3 A decision point is a concentration level statisticallyderived based on a specified decision error and is used in adecision rule for the purpose of choosing between alternativeactions.1.4 This practice derives the decision point and confidencelimit in the framework of a statistical test of hypothesis underthree different presumptions.The relationship between deci-sion point and confidence limit is also described.1.5 Determination of decision points and confidence limitsfor statistics other than mean concentration is not covered inthis practice.This practice also assumes that the data arenormally distributed.When this assumption does not apply,atransformation to normalize the data may be needed.If otherstatistical tests such as nonparametric methods are used in thedecision rule,this practice may not apply.When there are manydata points below the detection limit,the methods in thispractice may not apply.2.Referenced Documents2.1 ASTM Standards:2D5792 Practice for Generation of Environmental Data Re-lated to Waste Management Activities:Development ofData Quality ObjectivesD4790 Terminology of Aromatic Hydrocarbons and RelatedChemicalsE456 Terminology Relating to Quality and StatisticsE1138 Terminology for Technical Aspects of Products Li-ability Litigation(Withdrawn 1995)32.2 Other Documents:USEPA(1989a)Statistical Analysis of Ground-Water Moni-toring Data at RCRA Facilities.Interim Final Guidance.Office of Solid Waste Management Division,Washington,D.C.(PB89-15-1047)4USEPA(1989b)Methods for Evaluating the Attainment ofCleanup Standards.Vol.1:Soils and Solid Media.Statis-tical Policy Branch(PM-223)4USEPA(1992)Statistical Methods for Evaluating the attain-ment of Superfund Cleanup Standards.Vol.2:Groundwa-ter.DRAFT,Statistical Policy Branch,Washington,D.C4USEPA(1994)Guidance for the Data Quality ObjectivesProcess.EPA QA/G4,Quality Assurance ManagementStaff,USEPA,September,199443.Terminology3.1 Definitions:3.1.1 decision point,nthe numerical value which causesthe decision maker to choose one of the alternative actions(forexample,conclusion of compliance or noncompliance).1This practice is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.01.01 onPlanning for Sampling.Current edition approved Sept.1,2009.Published November 2009.Originallyapproved in 1998.Last previous edition approved in 2003 as D62501998(2003).DOI:10.1520/D6250-98R09.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from the Superintendent of Documents,U.S.Government PrintingOffice,Washington,DC 20402.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.1.1 DiscussionIn the context of this practice,thenumerical value is calculated in the planning stage and prior tothe collection of the sample data,using a specified hypothesis,decision error,an estimated standard deviation,and number ofsamples.In environmental decisions,a concentration limit suchas a regulatory limit usually serves as a standard for judgingattainment of cleanup,remediation,or compliance objectives.Because of uncertainty in the sample data and other factors,actual cleanup or remediation,for example,may have to go toa level