ASTM D6000-96e1

e1
Designation: D 6000 – 96
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Guide for
Presentation of Water-Level Information From Ground-Water
1
Sites
This standard is issued under the fixed designation D 6000; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1
e NOTE—Paragraph 1.10 was added editorially October 1998.
coordinated measurement). The judgment of what is a critical time period
1. Scope
must be made by a project investigator who is familiar with the hydrology
1.1 This guide covers a series of options, but does not
of the area.
specify a course of action. It should not be used as the sole
1.5 Where hydraulic heads are measured in a short period of
criterion or basis of comparison, and does not replace or relieve
time, for example, a day, from each of several horizontal
professional judgment.
locations within a specified depth range, or hydrogeologic unit,
1.2 This guide summarizes methods for the presentation of
or identified aquifer, a potentiometric surface can be drawn for
water-level data from ground-water sites.
that depth range, or unit, or aquifer. Water levels from different
NOTE 1—As used in this guide, a site is meant to be a single point, not
vertical sites at a single horizontal location may be averaged to
a geographic area or property, located by an X, Y, and Z coordinate
a single value for the potentiometric surface when the vertical
position with respect to land surface or a fixed datum. A ground-water site
gradients are small compared to the horizontal gradients.
is defined as any source, location, or sampling station capable of
producing water or hydrologic data from a natural stratum from below the
NOTE 4—The potentiometric surface assists in interpreting the gradient
surface of the earth. A source or facility can include a well, spring or seep,
and horizontal direction of movement of water through the aquifer.
and drain or tunnel (nearly horizontal in orientation). Other sources, such
Phenomena such as depressions or sinks caused by withdrawal of water
as excavations, driven devices, bore holes, ponds, lakes, and sinkholes,
from production areas and mounds caused by natural or artificial recharge
which can be shown to be hydraulically connected to the ground water, are
are illustrated by these potentiometric maps.
appropriate for the use intended.
1.6 Essentially all water levels, whether in confined or
1.3 The study of the water table in aquifers helps in the
unconfined aquifers, fluctuate over time in response to natural-
interpretation of the amount of water available for withdrawal,
and human-induced forces.
aquifer tests, movement of water through the aquifers, and the
NOTE 5—The fluctuation of the water table at a ground-water site is
effects of natural and human-induced forces on the aquifers.
caused by several phenomena. An example is recharge to the aquifer from
1.4 A single water level measured at a ground-water site
precipitation. Changes in barometric pressure cause the water table to
gives the height of water at one vertical position in a well or
fluctuate because of the variation of air pressure on the ground-water
borehole at a finite instant in time. This is information that can
surface, open bore hole, or confining sediment. Withdrawal of water from
be used for preliminary planning in the construction of a well
or artificial recharge to the aquifer should cause the water table to fluctuate
or other facilities, such as disposal pits. in response. Events such as rising or falling levels of surface water bodies
(nearby streams and lakes), evapotranspiration induced by phreatophytic
NOTE 2—Hydraulic head measured within a short time from a series of
consumption, ocean tides, moon tides, earthquakes, and explosions cause
sites at a common (single) horizontal location, for example, a specially
fluctuation. Heavy physical objects that compress the surrounding sedi-
constructed multi-level test well, indicate whether the vertical hydraulic
ments, for example, a passing train or car or even the sudden load effect
gradient may be upward or downward within or between the aquifer (see
of the starting of a nearby pump, can cause a fluctuation of the water table
7.2.1).
2
(1).
NOTE 3—The phrases “short time period” and “finite instant in time”
1.7 This guide covers several techniques developed to assist
are used throughout this guide to describe the interval for measuring
several project-related ground-water levels. Often the water levels of in interpreting the water table within aquifers. Tables and
ground-water sites in an area of study do not change significantly in a
graphs are included.
short time, for example, a day or e
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