8224

• UCREFRP Catalog Number: 8224
• Author: Lapham, W. W., F. D. Wilde and M. T. Koterba.
• Title: Ground-Water Data-Collection Protocols and Procedures for hte National Water-Quality Assessment Progra
• USFW Year: 1995.
• USFW - Doc Type: Selection, Installation, and Documentation of Wells, and collection of Related Data.
• Copyright Material: NO

time, such as turbidity, or at a minimum, the visual appearance of the discharge water; and (5)
information about well characteristics, such as the total depth of the well, the well diameter, the
depth(s) to the screened or open intervals, and the water level in the well.
Information collected during development can be used to evaluate requirements for sam-
pling. Estimates of the recovery rate and recovery time of the water level in the well after pump-
ing can be used to estimate the time required for purging the well prior to sampling. If the
recovery rate of the water level in the well is slow even after development, it might be necessary
to plan purging of the well on one day and sampling the well on the following day. The recovery
time can be used to determine the pumping rates to purge and sample the well and to determine
if an alternative method of pumping the well is required.
Factors that affect the well development and the effort required depend on aquifer charac-
teristics, the drilling method used to install the well, and well characteristics. Traditionally,
methods of well development are selected to optimize on the capacity of a well. Because a pri-
mary objective for wells used in the NAWQA Program is water-quality sampling, methods for
developing wells must be evaluated and selected on the basis of the probable effect on ground-
water chemistry. The best development techniques to restore the chemical quality of aquifer
pore water to its predrilled condition are those that avoid the introduction of air, foreign water,
and other foreign fluids into the aquifer during the development process. This reduces well-
development options, but is critical to ensuring that the effect of development on ground-water
chemistry is minimized. The following methods for well development in the NAWQA Program,
in the order of recommended use, are: bailing; mechanical surging; pumping or overpumping,
and backwashing; indirect eduction jetting; backwashing; and jetting and surging with water or
air (W. Lapham, U.S. Geological Survey, written commun., 1995--see footnote 1; U.S. Bureau
of Reclamation, 1977; Anderson, 1984; Driscoll, 1986; Aller and others, 1989; and Shuter and
Teasdale, 1989).
Documentation
The criteria for well selection and information about wells selected for sampling are to be
documented in permanent files. Careful and complete documentation aids in interpretation of
ground-water data and provides historical reference for future use of the well. In addition, doc-
umentation of network-design information for each Study-Unit Survey, Land-Use Study, and
Flowpath Study is required. Types of network-design information include network identifica-
tion, personnel involved, well selection and installation information, and field activities. An
example form is provided in an internal document entitled "gw.network.documentation"
(P. Leahy, U.S. Geological Survey, written commun., February 4, 1994).
A paper or electronic well site file should be maintained for each well sampled by NAWQA
Study Units. Information in this file begins with a well-information check list (fig. 7). As infor-
mation about the well site is collected, it is added to the site file.
It is USGS policy,,that all of the routine ground-water data collected must be stored in the
computer files of the National Water Information System. The USGS, Office of Ground Water,
interprets "routine" data collection of the USGS to include "all ground-water data collected by
WRD basic-data programs and district projects" (Office of Ground Water Technical Memoran-
dum No. 93-03, written commun., 1993).
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