1、Designation: D 6030 96 (Reapproved 2008)Standard Guide forSelection of Methods for Assessing Ground Water orAquifer Sensitivity and Vulnerability1This standard is issued under the fixed designation D 6030; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 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 guide covers information needed to select one ormore methods for assessing the
3、 sensitivity of ground water oraquifers and the vulnerability of ground water or aquifers towater-quality degradation by specific contaminants.1.2 This guide may not be all-inclusive; it offers a series ofoptions and does not specify a course of action. It should not beused as the sole criterion or
4、basis of comparison, and does notreplace professional judgment.1.3 This guide is to be used for evaluating sensitivity andvulnerability methods for purposes of land-use management,water-use management, ground-water protection, governmentregulation, and education. This guide incorporates descriptions
5、of general classes of methods and selected examples withinthese classes but does not advocate any particular method.1.4 LimitationsThe utility and reliability of the methodsdescribed in this guide depend on the availability, nature, andquality of the data used for the assessment; the skill, knowl-ed
6、ge, and judgment of the individuals selecting the method; thesize of the site or region under investigation; and the intendedscale of resulting map products. Because these methods arebeing continually developed and modified, the results shouldbe used with caution. These techniques, whether or not th
7、eyprovide a specific numeric value, provide a relative rankingand assessment of sensitivity or vulnerability. However, arelatively low sensitivity or vulnerability for an area does notpreclude the possibility of contamination, nor does a highsensitivity or vulnerability necessarily mean that ground
8、wateror an aquifer is contaminated.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user
9、 of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action. This document cannot r
10、eplace education orexperience and should be used in conjunction with professionaljudgment. Not all aspects of this guide may be applicable in allcircumstances. This ASTM standard is not intended to repre-sent or replace the standard of care by which the adequacy ofa given professional service must b
11、e judged, nor should thisdocument be applied without consideration of a projects manyunique aspects. The word “Standard” in the title of thisdocument means only that the document has been approvedthrough the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relating
12、 to Soil, Rock, and ContainedFluidsD 5447 Guide for Application of a Ground-Water FlowModel to a Site-Specific ProblemD 5490 Guide for Comparing Ground-Water Flow ModelSimulations to Site-Specific InformationD 5549 Guide for The Contents of Geostatistical Site Inves-tigation Report3D 5717 Guide for
13、Design of Ground-Water MonitoringSystems in Karst and Fractured-Rock Aquifers3D 5880 Guide for Subsurface Flow and Transport Modeling3. Terminology3.1 DefinitionsMany of the terms discussed in this guideare contained in Terminology D 653. The reader should refer tothis guide for definitions of selec
14、ted terms.3.2 Definitions:1This guide is under the jurisdiction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.21 on Ground Water andVadose Zone Investigations.Current edition approved Sept. 15, 2008. Published November 2008. Originallyapproved in 1996. Las
15、t previous edition approved in 2002 as D 603096(2002).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.3Withdr
16、awn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1 ground-water region, nan extensive area whererelatively uniform geology and hydrology contr
17、ols groundwater movement.3.2.2 hydrogeologic setting, na composite description ofall the major geologic and hydrologic features which affect andcontrol ground-water movement into, through, and out of anarea (1).43.2.3 sensitivity, nin ground water, the potential forground water or an aquifer to beco
18、me contaminated based onintrinsic hydrogeologic characteristics. Sensitivity is not de-pendent on land-use practices or contaminant characteristics.Sensitivity is equivalent to the term “intrinsic ground-watervulnerability” (2).3.2.3.1 DiscussionHydrogeologic characteristics includethe natural prope
19、rties of the soil zone, unsaturated zone, andsaturated zone.3.2.4 vulnerability, nin ground water, the relative easewith which a contaminant can migrate to ground water or anaquifer of interest under a given set of land-use practices,contaminant characteristics, and sensitivity conditions. Vulner-ab
20、ility is equivalent to “specific ground-water vulnerability.”4. Significance and Use4.1 Sensitivity and vulnerability methods can be applied toa variety of hydrogeologic settings, whether or not they containspecifically identified aquifers. However, some methods arebest suited to assess ground water
21、 within aquifers, while othersassess ground water above aquifers or ground water in areaswhere aquifers have not been identified.4.1.1 Intergranular media systems, including alluvium andterrace deposits, valley fill aquifers, glacial outwash, sand-stones, and unconsolidated coastal plain sediments a
22、re charac-terized by intergranular flow, and thus generally exhibit slowerand more predictable ground-water velocities and directionsthan in fractured media. Such settings are amenable to assess-ment by the methods described in this guide. Hydrologicsettings dominated by fracture flow or flow in sol
23、ution open-ings are generally not amenable to such assessments, andapplication of these techniques to such settings may providemisleading or totally erroneous results.4.2 The methods discussed in this guide provide users withinformation for making land- and water-use managementdecisions based on the
24、 relative sensitivity or vulnerability ofunderlying ground water or aquifers to contamination. Mostsensitivity and vulnerability assessment methods are designedto evaluate broad regional areas for purposes of assistingfederal, state, and local officials to identify and prioritize areaswhere more det
25、ailed assessments are warranted, to design andlocate monitoring systems, and to help develop optimumground-water management, use and protection policies. How-ever, some of these methods are independent of the size of thearea evaluated and, therefore, can be used to evaluate theaquifer sensitivity an
26、d vulnerability of any specific area.4.3 Many methods for assessing ground-water sensitivityand vulnerability require information on soils, and for sometypes of potential ground-water contaminants, soil is the mostimportant factor affecting contaminant movement and attenu-ation from the land surface
27、 to ground water. The relativelylarge surface area of the clay-size particles in most soils and thesoils content of organic matter provide sites for the retardationand degradation of contaminants. Unfortunately, there aresignificant differences in the definition of soil between thesciences of hydrog
28、eology, engineering, and agronomy. For thepurposes of this guide, soils are considered to be thoseunconsolidated organic materials and solid mineral particlesthat have been derived from weathering and are characterizedby significant biological activity. In the United States, thesetypically include u
29、nconsolidated materials that occur to a depthof2to3mormore.4.3.1 In many areas, significant thicknesses of unconsoli-dated materials may occur below the soil. Retardation, degra-dation, and other chemical attenuation processes are typicallyless than in the upper soil horizons. These underlying mater
30、ialsmay be the result of depositional processes or may have formedin place by long-term weathering processes with only limitedbiological activity. Therefore, when compiling the data re-quired for assessing ground-water sensitivity and vulnerability,it is important to distinguish between the soil zon
31、e and theunderlying sediments and to recognize that the two zones havesignificantly different hydraulic and attenuation properties.5. Description of Methods5.1 Hydrogeologic Settings and Scoring MethodsThisgroup of methods includes those that involve geologic map-ping, evaluation, and scoring of hyd
32、rogeologic characteristicsto produce a composite sensitivity map or composite vulner-ability map, or both. The methods range from purely descrip-tive of hydrogeologic settings to methods incorporating nu-merical scoring. They can include descriptive information orquantitative information, or both, a
33、nd the maps can be appliedas a “filter” to exclude specific hydrogeologic units fromfurther consideration or select sensitive areas for further study.5.1.1 The concept of assessing ground-water sensitivity andvulnerability is relatively recent and still developing. Thus, themethods presented differ
34、because they have been developed fordifferent purposes by different researchers using various typesof data bases in several hydrogeologic settings. These methodshave been divided into three groups: assessments using hydro-geologic settings without scoring or rankings, assessments inwhich hydrogeolog
35、ic setting information is combined withranking or scoring of hydrologic factors, and assessments usingscoring methods applied without reference to the hydrogeo-logic setting. The groups are not exclusive but overlap. Each ofthese methods produces relative, not absolute, results whetheror not it prod
36、uces a numerical score. Sensitivity analyses canbe used as the basis for a vulnerability assessment by addingthe information on potential point and non-point contaminantsources.5.1.2 Hydrogeologic Settings, No Scoring or RankingHydrogeologic mapping has been widely used to provideaquifer sensitivity
37、 information. This subgroup of methodsincludes those that generally present information as compositehydrogeologic maps that can be used for multiple purposes.The maps can be used individually to make a variety of4The boldface numbers in parentheses refer to a list of references at the end ofthis sta
38、ndard.D 6030 96 (2008)2land-use decisions or used as a basis for ground-water andaquifer sensitivity evaluations. Although derivative ground-water and aquifer sensitivity maps can be prepared, anygeologic or hydrogeologic map could potentially be used toassess sensitivity. In settings where quantita
39、tive data arelacking, hydrogeologic maps can allow the same conclusions,with the same level of confidence, as scoring methods. Hydro-geologic settings were mapped in detail without scoring orranking in the Denver Colorado, United States area by Hearneand others (3).5.1.2.1 Sensitivity assessments ba
40、sed on hydrogeologic set-tings with no scoring or ranking can be used to assessground-water or aquifer vulnerability by overlaying informa-tion on potential point or non-point contamination sources. Forexample, the sensitivity map included in Ref (3) has been usedin combination with a series of maps
41、 entitled “Land UsesWhich Affect Ground-Water Management” (4) to conductvulnerability assessments at specific sites within the greaterDenver area.5.1.3 Hydrogeologic Settings with Ranking or Scoring, orBothThis group of methods includes those which assessground-water or aquifer sensitivity within or
42、 among varioushydrogeologic settings using specific criteria to rank or scoreareas beneath which the ground water or aquifers have differentpotentials for becoming contaminated. The assessment isusually based on two or more hydrogeologic criteria. Forexample, material texture and depth to aquifer ar
43、e parametersthat are commonly used to establish criteria (5-10). Criteria,once defined, can then be ranked or scored, or both.5.1.3.1 Assessing vulnerability from point and non-pointsources of potential contamination (for example, leaking tanks,waste generators, landfills, and abandoned hazardous wa
44、stesites) is accomplished by mapping their location on a sensitiv-ity map (for example, numerous waste-generation sites in anarea of low sensitivity would result in a relatively lowvulnerability rank, all other factors being equal). This mappingmethod is particularly useful for evaluating the vulner
45、ability ofa large region. However, it can also be used to target smallerareas of particular concern where more detailed investigationsmay be needed. For example, Shafer (11) mapped regionalaquifer vulnerability based on sensitivity analysis. Bhagwatand Berg (12) defined aquifer sensitivity according
46、 to depth toaquifers and the characteristics of the geologic materials. Thesensitivity map was combined with information showing thedistribution of waste-source sites per zip code per square mile.Highly vulnerable areas have aquifers at or near the surface andcontain numerous point sources of potent
47、ial contaminationwith mobile contaminants. Areas of low vulnerability havedeep ground water or no aquifers and contain few potentialcontaminant sources or relatively immobile contaminants. Thisvulnerability information was then used to establish ground-water protection planning regions.5.1.4 Scoring
48、, Without Hydrogeologic SettingsThis cat-egory includes those methods that use qualitative ranking orquantitative scoring with hydrogeologic information, but with-out subdividing the area on the basis of hydrogeologic settings.Methods were developed to have universal application andwere intended to
49、be used consistently to provide uniformresults regardless of location. The methods are useful forapplications that require a consistent approach over large areas,however, these methods can be complex and may require muchunnecessary data preparation. Furthermore, because criteriaselection and ranking are subjective, the final scores may bemisleading.5.1.4.1 These methods classify a site or region based on aranking or a numerical score derived from hydrogeologicalinformation irrespective of the different hydrogeologic settingsthat may be present within the mapped area. Sco
