- 标准号：ASTM D6030-1996(2008)
- 发布日期：1996
- 英文题名：Standard Guide for Selection of Methods for Assessing Groundwater or Aquifer Sensitivity and Vulnerability
- 英文主题词：aquifers ; contamination ; ground water flow ; pollution ; Aquifers ; Contamination--soil ; Ground water ; Pollution ; Water quality degradation
- 标准状态：现行
- 发布单位：US-ASTM
- 国际标准分类号：13.060.10
- 载体形态：9P.;A4
- 中国标准分类号：P12
- 国别：美国材料与试验协会
Sensitivity and vulnerability methods can be applied to a variety of hydrogeologic settings, whether or not they contain specifically identified aquifers. However, some methods are best suited to assess ground water within aquifers, while others assess ground water above aquifers or ground water in areas where aquifers have not been identified.
Intergranular media systems, including alluvium and terrace deposits, valley fill aquifers, glacial outwash, sandstones, and unconsolidated coastal plain sediments are characterized by intergranular flow, and thus generally exhibit slower and more predictable ground-water velocities and directions than in fractured media. Such settings are amenable to assessment by the methods described in this guide. Hydrologic settings dominated by fracture flow or flow in solution openings are generally not amenable to such assessments, and application of these techniques to such settings may provide misleading or totally erroneous results.
The methods discussed in this guide provide users with information for making land- and water-use management decisions based on the relative sensitivity or vulnerability of underlying ground water or aquifers to contamination. Most sensitivity and vulnerability assessment methods are designed to evaluate broad regional areas for purposes of assisting federal, state, and local officials to identify and prioritize areas where more detailed assessments are warranted, to design and locate monitoring systems, and to help develop optimum ground-water management, use and protection policies. However, some of these methods are independent of the size of the area evaluated and, therefore, can be used to evaluate the aquifer sensitivity and vulnerability of any specific area.
Many methods for assessing ground-water sensitivity and vulnerability require information on soils, and for some types of potential ground-water contaminants, soil is the most important factor affecting contaminant movement and attenuation from the land surface to ground water. The relatively large surface area of the clay-size particles in most soils and the soils'' content of organic matter provide sites for the retardation and degradation of contaminants. Unfortunately, there are significant differences in the definition of soil between the sciences of hydrogeology, engineering, and agronomy. For the purposes of this guide, soils are considered to be those unconsolidated organic materials and solid mineral particles that have been derived from weathering and are characterized by significant biological activity. In the United States, these typically include unconsolidated materials that occur to a depth of 2 to 3 m or more.
In many areas, significant thicknesses of unconsolidated materials may occur below the soil. Retardation, degradation, and other chemical attenuation processes are typically less than in the upper soil horizons. These underlying materials may be the result of depositional processes or may have formed in place by long-term weathering processes with only limited biological activity. Therefore, when compiling the data required for assessing ground-water sensitivity and vulnerability, it is important to distinguish between the soil zone and the underlying sediments and to recognize that the two zones have significantly different hydraulic and attenuation properties.
1.1 This guide covers information needed to select one or more methods for assessing the sensitivity of ground water or aquifers and the vulnerability of ground water or aquifers to water-quality degradation by specific contaminants.
1.2 This guide may not be all-inclusive; it offers a series of options and does not specify a course of action. It should not be used as the sole criterion or basis of comparison, and does not replace professional judgment.
1.3 This guide is to be used for evaluating sensitivity and vulnerability......