ASTM_D_5786_-_17.pdf

Designation:D578617Standard Practice for(Field Procedure)for Constant Drawdown Tests in FlowingWells for Determining Hydraulic Properties of AquiferSystems1This standard is issued under the fixed designation D5786;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.Scope*1.1 This practice covers the methods for controlling draw-down and measuring discharge rates and head to analyze thehydraulic properties of an aquifer or aquifers.1.2 This practice is used in conjunction with analyticalprocedures such as those of Jacob and Lohman(1)/(2),2andHantush(3).1.3 The appropriate field and analytical procedures fordetermining hydraulic properties of aquifer systems are se-lected as described in Guide D4043.1.4 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 limitations prior to use.1.5 This practice offers a set of instructions for performingone or more specific operations.This document cannot replaceeducation or experience and should be used in conjunctionwith professional judgment.Not all aspects of this practice maybe applicable in all circumstances.This ASTM standard is notintended to represent or replace the standard of care by whichthe adequacy of a given professional 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.2.Referenced Documents2.1 ASTM Standards:3D653 Terminology Relating to Soil,Rock,and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4043 Guide for Selection of Aquifer Test Method inDetermining Hydraulic Properties by Well Techniques3.Terminology3.1 DefinitionsFor common definitions of terms used inthis practice,refer to Terminology D653.4.Summary of Practice4.1 This practice describes the field procedures for conduct-ing an aquifer test on a well that is flowing,that is,the head inthe well remains above the top of the well casing.This methodinvolves inducing a constant drawdown and measuring thevarying discharge rate from the control well.5.Significance and Use5.1 Constant drawdown test procedures are used with ap-propriate analytical procedures to determine transmissivity,hydraulic conductivity,and storage coefficient of aquifers.NOTE1The quality of the result produced by this standard isdependent on the competence of the personnel performing it and thesuitability of the equipment and facilities used.Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc.Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results.Reliable results depend on many factors:Practice D3740provides a means of evaluating some of those factors.6.Apparatus6.1 Various types of equipment can be used to measure theflow rate of the well.The equipment shall be sized so that itdoes not constrict the flow rate from the well.6.2 An apparatus shall be placed on the control welldischarge line such that the well can be shut in to prevent flowprior to conducting this field procedure and so that theapparatus will not constrict flow from the well when it isallowed to flow.1This practice is 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 Jan.1,2017.Published January 2017.Originallyapproved in 1995.Last previous edition approved in 2012 as D5786 95(2012).DOI:10.1520/D5786-17.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For 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.*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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 6.3 Head measurements can be made using one