ASTM D5920-14

Standard Test Method [Analytical Procedure] for Tests of Anisotropic Unconfined Aquifers by Neuman Method

STANDARD published on 1.6.2014

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The information about the standard:

Designation standards: ASTM D5920-14
Note: WITHDRAWN
Publication date standards: 1.6.2014
SKU: NS-33080
The number of pages: 9
Approximate weight : 27 g (0.06 lbs)
Country: American technical standard
Category: Technical standards ASTM

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Geology. Meteorology. Hydrology

Annotation of standard text ASTM D5920-14 :

Keywords:

anisotropic aquifers, aquifers, aquifer tests, control wells, groundwater, hydraulic properties, observation wells, transmissivity, unconfined aquifers, ICS Number Code 07.060 (Geology. Meteorology. Hydrology)

Additional information

Significance and Use

5.1 Assumptions:

5.1.1 The control well discharges at a constant rate, 5.1.2 The control well, observation wells, and piezometers are of infinitesimal diameter.

5.1.3 The unconfined aquifer is homogeneous and really extensive.

5.1.4 Discharge from the control well is derived initially from elastic storage in the aquifer, and later from gravity drainage from the water table.

5.1.5 The geometry of the aquifer, control well, observation wells, and piezometers is shown in Fig. 2. The geometry of the test wells should be adjusted depending on the parameters of interest.

5.2 Implications of Assumptions:

5.2.1 Use of the Neuman (1) method assumes the control well is of infinitesimal diameter. The storage in the control well may adversely affect drawdown measurements obtained in the early part of the test. See 5.2.2 of Test Method D4106 for assistance in determining the duration of the effects of well-bore storage on drawdown.

5.2.2 If drawdown is large compared with the initial saturated thickness of the aquifer, the late-time drawdown may need to be adjusted for the effect of the reduction in saturated thickness. Section 5.2.3 of Test Method D4106 provides guidance in correcting for the reduction in saturated thickness. According to Neuman 5.3 Practice D3740 provides evaluation factors for the activities in this guide.

Note 1: The quality of the result produced by this guide is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this guide are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

1. Scope

1.1 This test method covers an analytical procedure for determining the transmissivity, storage coefficient, specific yield, and horizontal-to-vertical hydraulic conductivity ratio of an unconfined aquifer. It is used to analyze the drawdown of water levels in piezometers and partially or fully penetrating observation wells during pumping from a control well at a constant rate.

1.2 The analytical procedure given in this test method is used in conjunction with Guide D4043 and Test Method D4050.

1.3 The valid use of the Neuman method is limited to determination of transmissivities for aquifers in hydrogeologic settings with reasonable correspondence to the assumptions of the theory.

1.4 The values stated in SI units are to be regarded as standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents

D4105-15	Standard Test Method for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined Aquifers by the Modified Theis Nonequilibrium Method
D653-22	Standard Terminology Relating to Soil, Rock, and Contained Fluids
D4106-20	Standard Practice for (Analytical Procedure) for Determining Transmissivity and Storage Coefficient of Nonleaky Confined Aquifers by the Theis Nonequilibrium Method
D6026-21	Standard Practice for Using Significant Digits and Data Records in Geotechnical Data
D3740-23	Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
D4043-17	Standard Guide for Selection of Aquifer Test Method in Determining Hydraulic Properties by Well Techniques
D4050-20	Standard Test Method for (Field Procedure) for Withdrawal and Injection Well Testing for Determining Hydraulic Properties of Aquifer Systems