GROUND-WATER DATA-COLLECTION PROTOCOLS AND PROCEDURES

FOR THE NATIONAL WATER-QUALITY ASSESSMENT PROGRAM:

SELECTION, INSTALLATION, AND DOCUMENTATION OF WELLS,

AND COLLECTION OF RELATED DATA

__________________________________________________________________________

__________________________________________________________________________

U.S. Geological Survey

Open-File Report 95-398

National Water-Quality Assessment Study Unit
GROUND-WATER DATA-COLLECTION PROTOCOLS AND PROCEDURES

FOR THE NATIONAL WATER-QUALITY ASSESSMENT PROGRAM:

SELECTION, INSTALLATION, AND DOCUMENTATION OF WELLS,

AND COLLECTION OF RELATED DATA

By Wayne W. Lapham, Franceska D. Wilde, and Michael T. Koterba

__________________________________________________________

U.S. Geological Survey

Open-File Report 95-398

Reston, Virginia

1995
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary Seal

U.S. GEOLOGICAL SURVEY

Gordon P. Eaton, Director

Any use of trade, product, or firm names is for descriptive purposes only

and does not imply endorsement by the U.S. Government.

_________________________________________________________________________

For additional information, write to: Copies of this report can be purchased from:

NAWQA - Mail Stop 413 U.S. Geological Survey

U.S. Geological Survey Earth Science Information Center

12201 Sunrise Valley Drive Open-File Reports Section

Reston, Virginia 22092 Box 25286, MS 517

Denver Federal Center

Denver, Colorado 80225
FOREWORD

The mission of the U.S. Geological Survey (USGS) is to assess the quantity and quality of the earth

resources of the Nation and to provide information that will assist resource managers and policymakers at

Federal, State, and local levels in making sound decisions. Assessment of water-quality conditions and

trends is an important part of this overall mission.

One of the greatest challenges faced by water-resources scientists is acquiring reliable information that

will guide the use and protection of the Nation's water resources. That challenge is being addressed by Federal, State, interstate, and local water-resource agencies and by many academic institutions. These organizations are collecting water-quality data for a host of purposes that include: compliance with permits and

water-supply standards; development of remediation plans for specific contamination problems; operational

decisions on industrial, wastewater, or water-supply facilities; and research on factors that affect water quality. An additional need for water-quality information is to provide a basis on which regional- and nationallevel policy decisions can be based. Wise decisions must be based on sound information. As a society we

need to know whether certain types of water-quality problems are isolated or ubiquitous, whether there are

significant differences in conditions among regions, whether the conditions are changing over time, and why

these conditions change from place to place and over time. The information can be used to help determine

the efficacy of existing water-quality policies and to help analysts determine the need for and likely consequences of new policies.

To address these needs, the U.S. Congress appropriated funds in 1986 for the USGS to begin a pilot program in seven project areas to develop and refine the National Water-Quality Assessment (NAWQA) Program.

In 1991, the USGS began full implementation of the program. The NAWQA Program builds upon an existing

base of water-quality studies of the USGS, as well as those of other Federal, State, and local agencies. The

objectives of the NAWQA Program are to:

- Describe current water-quality conditions for a large part of the Nation's freshwater streams, rivers, and

aquifers.

- Describe how water quality is changing over time.

- Improve understanding of the primary natural and human factors that affect water-quality

conditions.

This information will help support the development and evaluation of management, regulatory, and monitoring decisions by other Federal, State, and local agencies to protect, use, and enhance water resources.

The goals of the NAWQA Program are being achieved through ongoing and proposed investigations of

60 of the Nation's most important river basins and aquifer systems, which are referred to as study units.

These study units are distributed throughout the Nation and cover a diversity of hydrogeologic settings.

More than two-thirds of the Nation's freshwater use occurs within the 60 study units and more than twothirds of the people served by public water-supply systems live within their boundaries.

National synthesis of data analysis, based on aggregation of comparable information obtained from the

study units, is a major component of the program. This effort focuses on selected water-quality topics using

nationally consistent information. Comparative studies will explain differences and similarities in observed

water-quality conditions among study areas and will identify changes and trends and their causes. The first

topics addressed by the national synthesis are pesticides, nutrients, volatile organic compounds, and aquatic

biology. Discussions on these and other water-quality topics will be published in periodic summaries of the

quality of the Nation's ground and surface water as the information becomes available.

This report is an element of the comprehensive body of information developed as part of the NAWQA

Program. The program depends heavily on the advice, cooperation, and information from many Federal,

State, interstate, Tribal, and local agencies and the public. The assistance and suggestions of all are greatly

appreciated.

Robert M. Hirsch

Chief Hydrologist

(signed)
CONTENTS

Page

Abstract ...................................................................................................................... 1

Introduction ................................................................................................................ 1

Overview of National Water-Quality Assessment Program............................... 2

Purpose and scope.............................................................................................. 5

Acknowledgments ............................................................................................. 5

Selection, installation, and documentation of wells, and collection of related data.... 8

Well selection .................................................................................................... 8

Well-selection criteria.................................................................................. 8

Well inventory ............................................................................................. 13

Well installation................................................................................................. 21

Preparation................................................................................................... 21

Well drilling................................................................................................. 33

Well completion........................................................................................... 36

Well development ....................................................................................... 39

Documentation............................................................................................. 40

Measurement of water levels and collection of additional hydrogeologic

 and geologic data ........................................................................................... 56

 Water levels ................................................................................................ 56

 Additional hydrogeologic and geologic data............................................... 58

References cited ........................................................................................................ 64

ILLUSTRATIONS

Page

Figure 1. Example of a well-inventory form for the National Water-Quality

 Assessment Program..................................................................... 16

2. Form for agreement to use an abandoned test hole or well.................. 19

3. Sample of Form 9-1483 (Aug. 1994), “Agreement for Installation,

Maintenance and Use of a Test Hole and/or Observation Well

on Private or _______ Property” ................................................... 22

4. Sketch showing general design of a monitoring well in unconsolidated

deposits for National Water-Quality Assessment Program

Land-Use and Flowpath Studies .................................................... 24

5. Sketch showing examples of monitoring-well designs in

semiconsolidated deposits and in rock........................................... 26

6. Sketch showing examples of three well-cluster designs ..................... 27

7. Example of a well-information check list for the National

Water-Quality Assessment Program.............................................. 41

8. Examples of forms used to record well-drilling, -construction, and

-completion information, and to diagram well construction .......... 45
ILLUSTRATIONS--Continued

Page

 9. Example of a form to summarize development of a well .................... 48

10. Examples of well-location and site-sketch maps and information

related to site conditions and restrictions....................................... 50

11. Land-use and land-cover field sheet for the 1991 Study Units,

National Water-Quality Assessment Program .............................. 53

12. Example of a form to record water-level data in a well....................... 57

TABLES

Page

Table 1. Components and attributes of the National Water-Quality

Assessment Program ground-water sampling design..................... 4

2. Summary of current (1995) required, recommended, and optional

water-quality constituents to be measured in the three

National Water-Quality Assessment Program ground-water

components of the Occurrence and Distribution Assessment ........ 6

3. Selection, design, and documentation criteria for wells used in

National Water-Quality Assessment Program Study-Unit

Surveys, Land-Use Studies, and Flowpath Studies........................ 9

4. Advantages and disadvantages of high-capacity and low-capacity

water-supply wells for water-quality studies ................................. 14

5. Relative leaching or sorption/desorption of casing and screen

materials for indicated water-quality constituent classes .............. 29

6. Some general characteristics of materials used for well casing

and screens ................................................................................... 30

7. Six-step procedure for decontamination of well-installation

equipment and materials ................................................................ 33

8. Factors to consider when selecting a drilling method ......................... 34

9. Summary matrix of relations between drilling criteria and drilling

methods ........................................................................................ 35

10. Characteristics of bentonite and cement as annular seals ................... 38

11. Information required for creation of files and storage of waterquality-related data in U.S. Geological Survey data bases

within the National Water Information System-I .......................... 44

12. Summary matrix of relative quality of aquifer property measured

or estimated using different sample-collection methods................ 60

13. Summary matrix of potential applications of borehole-geophysical

logs commonly used in ground-water investigation....................... 62
CONVERSION FACTORS AND ABBREVIATIONS

____________________________________________________________________________________

Multiply By To obtain

____________________________________________________________________________________

Length

inch (in.) 25.4 millimeter (mm)

2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

square foot (ft2) 0.0929 square meter (m2)

square mile (mi2) 2.590 square kilometer (km2)

Volume

gallon (gal) 3.785 liter

3785 milliliter

Flow

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

cubic foot per second per 10.93 liter per second per square

 square mile [(ft3/s)/mi2] kilometer[(L/s)/km2]

foot per mile (ft/mi) 0.1894 meter per kilometer (m/km)

gallon per minute (gal/min) 0.06308 liter per second (L/s)

million gallons per day (Mgal/d) 0.04381 cubic meter per second (m|/s)

Hydraulic Conductivity

foot per day (ft/d) 0.3048 meter per day (m/d)

Transmissivity

square foot per day (ft2/d) 0.09290 square meter per day (m2/d)
CONVERSION FACTORS AND ABBREVIATIONS--Continued

Physical and Chemical Water-Quality Units

Temperature: Water and air temperature are given in degrees Celsius (°C), which can be converted to degrees Fahrenheit (°F) by use of the following equation:

°F = 1.8(°C) + 32

Specific electrical conductance of water is expressed in microsiemens per centimeter at

25 degrees Celsius (μS/cm). This unit is equivalent to micromhos per centimeter at 25 degrees

Celsius.

milligrams per liter (mg/L) or micrograms per liter (μg/L): Milligrams per liter is a unit expressing the concentration of chemical constituents in solution as weight (milligrams) of solute per

unit volume (liter) of water. One thousand micrograms per liter is equivalent to one milligram

per liter. For concentrations less than 7,000 mg/L, the numerical value is the same as for concentrations in parts per million.

millivolt (mv): A unit of electromotive force equal to one thousandth of a volt.

nephelometric turbidity unit (NTU): A measure of turbidity in a water sample, roughly equivalent

to Formazin turbidity unit (FTU) and Jackson turbidity unit (JTU).

Other

Sea level: In this report "sea level" refers to the National Geodetic Vertical Datum of 1929

(NGVD of 1929)--a geodetic datum derived from a general adjustment of the first-order level

nets of both the United States and Canada, formerly called "Mean Sea Level of 1929."

______________________________________________________________________________
1

GROUND-WATER DATA-COLLECTION PROTOCOLS AND PROCEDURES

FOR THE NATIONAL WATER-QUALITY ASSESSMENT PROGRAM:

SELECTION, INSTALLATION, AND DOCUMENTATION OF WELLS,

AND COLLECTION OF RELATED DATA

By Wayne W. Lapham, Franceska D. Wilde, and Michael T. Koterba

ABSTRACT

Protocols for well installation and documentation are included in a 1989 report written

for the National Water-Quality Assessment (NAWQA) Pilot Program of the U.S. Geological

Survey (USGS). These protocols were reviewed and revised to address the needs of the fullscale implementation of the NAWQA Program that began in 1991. This report, which is a collaborative effort between the National Water-Quality Assessment Program and the Office of

Water Quality, is the result of that review and revision.

This report describes protocols and recommended procedures for the collection of data

from wells for the NAWQA Program. Protocols and procedures discussed are well selection,

installation of monitoring wells, documentation, and the collection of water level and additional hydrogeologic and geologic data.

INTRODUCTION

Although the report Well Installation and Documentation, and Ground-Water Sampling

Protocols for the Pilot National Water-Quality Assessment Program (Hardy and others, 1989)

was developed for the National Water-Quality Assessment (NAWQA) Pilot Program, it has

been circulated widely within the U.S. Geological Survey (USGS). The full-scale implementation of the NAWQA Program in 1991 required updating of the NAWQA Pilot Program protocols (Hardy and others, 1989) and more detailed information on recommended procedures

for collecting data for the ground-water component of the NAWQA Program. There also has

been a need for a broader based report that establishes and documents water-resources datacollection protocols and procedures for the entire USGS. These needs have resulted in collaboration between the Office of Water Quality and the NAWQA Program to produce two companion reports.1

This report describes protocols and recommended procedures for the selection, installation, and documentation of wells and collection of hydrogeologic and geologic data for the

full-scale NAWQA Program. The planned companion report will be a broader based reference

for the collection of ground-water-quality data throughout the USGS. In addition to updating

and expanding the report by Hardy and others (1989), this report complements other reports,

including those that describe NAWQA protocols for the collection of ground-water-quality

1For further information about the status of these planned reports contact the Office of Water Quality,

U.S. Geological Survey, 412 National Center, Reston, VA 22092.
2

samples and related data (Koterba and others, in press), the NAWQA Program design (Gilliom

and others, 1995; Alley and Cohen, 1991), the conceptual framework of the NAWQA Program

(Leahy and Wilber, 1991a and b; Hirsch and others, 1988; Cohen and others, 1988), an implementation plan for the NAWQA Program (Leahy and others, 1990), and a description of a

quality-assurance plan for the NAWQA Pilot Program (Mattraw and others, 1989).

For the purposes of this report, a protocol identifies a course of action that is mandatory

under most circumstances as a consequence of USGS and NAWQA policies. For example,

decontaminating equipment according to prescribed methods between uses to avoid crosscontamination of the aquifer is a protocol. A recommended procedure is one that generally is

preferred over other procedures that are available or commonly used. A recommended procedure

generally conforms to rules for good field practices and is expected to result in reproducible data

of desired and defined quality. Recommended procedures are not protocols because they either

are too restrictive or possibly inappropriate in some situations. For example, one recommended

procedure is to measure the water level in the well before sampling. This is not possible for many

water-supply wells.

Although modifications to methods are likely as new technologies evolve, the described

protocols and recommended procedures reflect methods of data collection and documentation

generally considered capable of reproducing data of known quality that are suitable for assessment, yet feasible to employ given limitations of time and funds. Their use also promotes consistency and comparability of ground-water data among Study Units in the NAWQA Program.

Overview of National Water-Quality Assessment Program

The USGS began full-scale implementation of the NAWQA Program in 1991. The goals

of the NAWQA Program are to: (1) provide a nationally consistent description of current waterquality conditions for a large part of the Nation's water resources; (2) define long-term trends in

water quality; and (3) identify, describe, and explain, as possible, the major factors that affect

observed water-quality conditions and trends (Hirsch and others, 1988).

The design concepts of the NAWQA Program are based in part on a pilot program that began in 1986. The NAWQA Pilot Program consisted of water-quality assessment in seven study

areas. These study areas were distributed geographically throughout the continental United

States and represented diverse hydrologic environments and water-quality conditions. Four of

the pilot assessments focused on surface water and three focused on ground water. The groundwater pilot study areas were the Carson River Basin in Nevada and California (Welch and Plume,

1987); the Central Oklahoma Aquifer in Oklahoma (Christenson and Parkhurst, 1987); and the

Delmarva Peninsula in Delaware, Maryland, and Virginia (Bachman and others, 1987).

The NAWQA Program design that has evolved from the pilot program consists of two major components: (1) Study-Unit Investigations of both surface and ground water and (2) National

Synthesis activities. The design provides information on water quality for policy makers and

managers at local, State, regional, and national scales.

Investigations of 60 Study Units, which range in area from 1,200 to more than 60,000

square miles, are ongoing or planned. The 60 Study Units include parts of most of the major river
3

basins and aquifer systems in the Nation, and incorporate about 60 to 70 percent of the Nation's

water use and population served by public water supply. Investigation in each Study Unit will

be conducted on a rotational rather than a continuous basis. One-third of the Study Units will

be studied intensively at a given time. For each Study Unit, a 3- to 4-year intensive period of

data collection and analysis will be alternated with a 6- to 7-year period of low-intensity assessment activities. The first intensive period of study for 20 of the 60 Study Units began in

1991, and another 20 began in 1994.

During the first cycle of intensive study, Study-Unit Investigations will consist of four

components: Retrospective Analysis; Occurrence and Distribution Assessment; Trend and

Change Assessment; and Case Studies (Gilliom and others, 1995). The Retrospective Analysis

forms the basis for evaluating what is known of water-quality conditions in a Study Unit and

what water-quality issues need further investigation. The Occurrence and Distribution Assessment builds on findings of the Retrospective Analysis to complete a broad assessment of current water-quality conditions and to identify important questions about sources, transport, fate,

and effects. The Trend and Change Assessment will identify long-term trends and changes in

water-quality conditions in each Study Unit. Case Studies will develop an improved understanding of questions about sources, transport, fate, and effects. These four components are

interrelated. It is anticipated that results from one component commonly will lead to changes

in approaches used in the other three components. The interaction among the four components

centers on the Occurrence and Distribution Assessment; therefore, the primary focus of investigations by all Study Units during the first cycle of intensive study is the Occurrence and Distribution Assessment.

The Occurrence and Distribution Assessment will characterize the broad-scale geographic and seasonal distributions of water-quality conditions in relation to major contaminant

sources and background conditions (Gilliom and others, 1995). For ground water, the focus of

this assessment will be on water-quality conditions of major water-supply or potential watersupply aquifers in each Study Unit. Emphasis is on the chemical quality of ground water associated with current human activities. The chemical quality of older (in excess of several

decades) ground water also is studied depending on factors such as environmental and hydrogeologic settings, water use, and water-quality issues in a Study Unit.

Currently (1995), the national emphasis in the Occurrence and Distribution Assessment

of ground water is on characterizing the occurrence and distribution of nutrients and selected

pesticides and volatile organic compounds. In addition, some Study Units are investigating

local concerns, such as trace elements and radionuclides.

The primary focus of the Occurrence and Distribution Assessment for ground water is on

spatial characterization of ground-water quality at several areal scales within each Study Unit.

Consideration of temporal changes in the water quality of the resource are incorporated in sampling design by the Study Unit/Program. This characterization is achieved through three primary components (table 1): (1) Study-Unit Survey; (2) Land-Use Studies; and (3) Flowpath

Studies. The Study-Unit Survey will be used, in conjunction with an analysis of available data,

to broadly characterize ground-water quality across a Study Unit, and Land-Use and Flowpath

Studies will build understanding of causal relations and processes (Gilliom and others, 1995).
4

Table 1. Components and attributes of the National Water-Quality Assessment Program

ground-water sampling design

[ mi2, square miles; km2, square kilometers]

1An indicator basin is a basin with homogeneous land use and physiographic conditions. Basins are chosen to

be as large and representative as possible while still encompassing primarily one Environmental Setting (Gilliom and

others, 1995).

Study component

Feature Study-Unit Survey Land-Use Studies Flowpath Studies

General

objective

To supplement existing data

in providing broad overview

of ground-water quality

within each Study Unit

To examine natural and human

factors that affect the quality

of shallow ground water that

underlies key types of land

use

To examine ground-water

quality along inferred

flowpaths and interactions of ground water

with surface water

Spatial

domain

Ground-water resource

throughout Study Unit

Uppermost part of ground-water

system in specified land-use

settings

Shallow flow systems in

specified settings

Selection

of areas

Aquifer system divided

typically into 3-5 subunits

on the basis of physiographic and hydrogeologic

features

Typically, 2 -4 Land-Use Studies

per Study Unit

Each land-use setting represents

a combination of a land-use

type and a hydrogeologic

subunit

Typically, 1-2 Flowpath

Studies per Study Unit

Generally, unconsolidated

shallow aquifers

Upper part of flowpath

generally lies within

one of land-use settings

examined in Land-Use

Studies

Typically, located in

indicator basin1 for

surface-water

sampling design

Number

of wells

sampled

Minimum of 30 wells in

each subunit

General goal for spatial

density is one well per

38 mi2 (100 km2)

Minimum of 30 wells in each

land-use setting

Typically, 10-12 wells

along flowpath and

10 wells for areal

sampling

Well-selection

strategy

Spatially distributed, with

random selection of suitable water-supply or

monitoring wells within

each subunit

Spatially distributed, with

random selection of suitable

water-supply wells or of sites

where monitoring wells can

be installed within each

Land-Use Study area

Generally, wells installed

by the Study Unit that

are distributed at multiple depths along flowpath and areally in

vicinity of flowpath

Temporal

sampling

strategy

Each well typically sampled

once during an intensive

period

Each well typically sampled

once during an intensive

period

Additional seasonal sampling

at selected wells in some

Study Units

Variable; multiple

samples from most

wells
5

Because Study-Unit ground-water components have different objectives, different

water-quality constituents could be measured (table 2). Thus, the protocols and procedures

for collecting ground-water-quality samples and data also could differ among components.

For example, data collection for a Study-Unit Survey generally implies samples are collected

for a broad suite of chemical constituents, whereas a Flowpath Study could conceivably focus

solely on a narrow category, such as nutrients. In general, however, water-quality constituents

to be measured are determined, at least in part, by the water-quality topics of national interest

selected for National Assessment. These topics can change over time. Current (1995) topics

selected for National Assessment are nutrients, pesticides, and volatile organic compounds.

Purpose and Scope

This report provides to investigators in the NAWQA Program the protocols and recommended procedures for the selection of supply, monitoring, or observation wells; installation

of monitoring wells; documentation of the well-selection and well-installation process; and

guidance regarding the collection of hydrogeologic and geologic data from wells. Technical

information that relates to the collection of ground-water-quality samples and data for

NAWQA are described in Koterba and others (in press). Technical information that relates to

protocols and recommended procedures described in either of these NAWQA reports are

discussed in greater detail in the planned companion reports being prepared to meet broader

based needs of the USGS.

Acknowledgments

The authors gratefully acknowledge the contributions and assistance of many colleagues

within the USGS in producing this document. In particular, thorough and thoughtful reviews

and discussions were provided by David W. Clark, Dorinda J. Gellenbeck, and W. Brian

Hughes for the National Water-Quality Assessment Program of the USGS. Editorial assistance was provided by Iris M. Collies.
6

Table 2. Summary of current (1995) required, recommended, and optional water-quality

constituents to be measured in the three National Water-Quality Assessment Program groundwater components of the Occurrence and Distribution Assessment

[Required water-quality constituents to be measured for the Occurrence and Distribution Assessment

are determined partly by the water-quality topics of national interest selected for National Assessment.

Topics selected for National Assessment (1994) are nutrients, pesticides, and volatile organic compounds. The topics selected can change over time. Quality-control samples also are required - types

of quality control samples depend on study component. Req, Required; Rec, Recommended; Opt,

Optional; NWQL, National Water Quality Laboratory; SC, Schedule; LC, Laboratory Code]

Water-quality constituent

or constituent class

Study-Unit

 Survey

Land-Use

 Studies

Flowpath

 Studies1 Method2

Field measurements

 - Temperature Req Req Req Field

 - Specific electrical

 conductance Req Req Req Field

 - pH Req Req Req Field

 - Dissolved oxygen Req Req Req Field

 - Acid neutralizing

 capacity (ANC)

 (unfiltered sample)3 Rec Rec Rec

Field

incremental

 - Alkalinity

 (filtered sample)3 Req Req Req Field

incremental

 - Turbidity4 Rec Rec Rec Field

Major inorganics Req Req Req NWQL SC2750

Nutrients Req Req Req NWQL SC2752

Filtered organic carbon Req Req Opt NWQL SC2085

Pesticides Req Req Opt NWQL SC2001/2010

NWQL SC2050/2051

Volatile organic

 compounds (VOCs) Req Req or Opt5 Req or Opt6 NWQL SC 2090

Radon Req Req or Rec7 Req or Rec6 NWQL LC 1369

Trace elements4 Opt Opt Opt NWQL SC 2703

Radium Opt Opt Opt NWQL-Opt

Uranium Opt Opt Opt NWQL-Opt

Tritium, tritium-helium,

 chlorofluorocarbons (CFCs)8 Rec Rec Rec

NWQL LC1565

(tritium)

Environmental isotopes9 Rec Rec Rec NWQL-Opt
7

Table 2. Summary of current (1995) required, recommended, and optional water-quality

constituents to be measured in the three National Water-Quality Assessment Program groundwater components of the Occurrence and Distribution Assessment--Continued

________________________________________________________________________________________

1Selection of constituents for measurement in Flowpath Studies is determined by Flowpath-Study

objectives. During at least the first round of sampling, however, the broad range of constituents

measured in Study-Unit Surveys and Land-Use Studies would be measured.

2Schedules and laboratory codes listed are required for Study Units that began their intensive

phase in 1991 or 1994, and apply until changed by National Program directive. Schedules for radium

and uranium can be selected by the Study Unit, but require NAWQA Quality-Assurance Specialist

approval. A detailed discussion is found in Koterba and others (in press).

3ANC (formerly referred to as unfiltered alkalinity) is measured on an unfiltered sample. Alkalinity is measured on a filtered sample. Study Unit could have collected ANC, alkalinity, or both to date.

4Turbidity measurements are required whenever trace-element samples are collected to evaluate

potential colloidal contributions to measured concentrations of iron, manganese, and other elements.

5VOCs are required at all urban Land-Use Study wells, but optional in agricultural Land-Use

Studies. If VOCs are chosen as part of an agricultural Land-Use Study, then they should be measured

in at least 20 of the Land-Use Study wells.

6VOCs are required at all urban flowpath wells for at least the first round of sampling. If VOCs

are measured in an agricultural Land-Use Study, then they should be measured at all Flowpath-Study

wells within that Land-Use Study for at least the first round of sampling.

7Radon is required at any Land-Use or Flowpath Study well if that well also is part of a StudyUnit Survey; otherwise, radon collection is recommended for Land-Use or Flowpath Study wells

located in likely source areas.

8Collection of tritium, tritium-helium, chlorofluorocarbons (CFCs), and/or other samples for

dating ground water is recommended, depending on hydrogeologic setting. For tritium methods, see

NWQL catalog; for CFCs, see Office of Water Quality Technical Memorandum No. 95.02 (unpublished document located in the USGS Office of Water Quality, MS 412, Reston, VA 22092).

9For a general discussion of the use of environmental isotopes in ground-water studies, see Alley

(1993).
8

SELECTION, INSTALLATION, AND DOCUMENTATION OF WELLS,

AND COLLECTION OF RELATED DATA

General guidance as well as the protocols required or procedures recommended for the

selection, installation, and documentation of wells used in the NAWQA Program are provided

in this report. For more extensive guidance and explanation of well-selection and well-installation procedures, the reader is referred to the companion report being prepared by the Office of

Water Quality (see footnote 1).

Requirements differ for the quality and types of data needed from wells for Study-Unit Surveys, Land-Use Studies, and Flowpath Studies. Most wells selected for a Study-Unit Survey will

be water-supply wells. Monitoring wells will be installed for Land-Use Studies and Flowpath

Studies because water-supply wells generally will not be suitable for those studies.

In this report, the term “water-supply well” is used to describe wells used for domestic,

municipal, commercial, industrial, and irrigation supply. The term “observation well” is used to

describe a well in which only water levels are measured. The term “monitoring well” is used to

describe a well whose primary purpose is sampling or direct measurement of water quality.

Well Selection

Selection of wells for Study-Unit Investigations involves (1) developing well-selection

criteria that address data-collection objectives, and (2) performing an inventory of water-supply,

observation, and monitoring wells in the locale of interest. Ultimately the decision to select a

well for NAWQA ground-water studies will be based on criteria (table 3) to determine that data

collected from the well are suitable for the intended use and from well-inventory information.

Documentation of the well-selection process includes the following: the selection criteria,

including their order of application and the reasons for the criteria; the locations of wells considered for selection; the characteristics of each well site, including ownership and access; well

design; methods of installation; and water-quality and other ancillary data and information that

supported selection or rejection of the well.

Well-Selection Criteria

Well-selection criteria aid in ensuring that data collected from the wells will meet the

respective study-component objective(s) (table 1). These criteria are applied in screening and

selecting all or a subset of the inventoried wells.

Table 3 outlines minimum criteria for selecting wells for water-quality monitoring. Table

3 also provides specific criteria that are study-objective driven for wells associated with each of

the NAWQA study components. Application of the selection criteria specific to each study component requires that all available information about wells in the study area be collected and included in the well inventory.
9

-

 Table 3. Selection, design, and documentation criteria for wells used in National Water-Quality

 Assessment Program Study-Unit Surveys, Land-Use Studies, and Flowpath Studies

[Drains, springs, or seeps will not be used to substitute for wells, but may be sampled as a

separate category]

Criteria That Apply For All Three Study Components

The well is suitably located in relation to the desired spatial and depth design. For example,

wells are screened only within the unit defined for study.

- The hydrogeologic unit (units) represented by the water level being measured is (are)

known.1

- The hydrogeologic unit (units) contributing water to the well is (are) known.1

Monitoring or observation wells that were installed to detect a known or suspected contaminant are to be avoided.

Wells located near roads and highways are avoided because of the common use of herbicides

and road-salt applications along roadsides. Where this is not possible, knowledge about roadside applications of chemicals, especially of herbicides, is documented.

Wells with filter packs extending over a long interval of the annulus of the well as compared

to the screened or open interval are to be avoided (the long packed interval can lead to uncertainty as to the source of water to the well).

The top of the screen is located at least several feet below the lowest anticipated position of the

water table (to reduce the chances of the well being dry during some periods of the year and to

avoid problems with interpreting data from partially saturated open intervals).

The integrity of well construction has been verified using verification checks where practical,

such as depth-to-bottom measurements.

The well construction and pumping equipment in the well are known to be of a type that are

not likely to affect the water-quality constituents of concern.2

Possible biases caused by pumping rate have been considered.

Selected or installed wells can be pumped at a rate that is adequate for sampling: typically,

on the order of at least 1 gallon per minute.

The sampling point should be located before any water treatment, pressure tanks, or holding

tanks.

For existing wells with pumps, only those with submersible pumps are selected. Wells with

water-lubricated pumps are selected in preference to wells with oil-lubricated pumps.

Wells with permanently installed suction-lift or gas-contact pumps are not selected.
10

Documentation Required

The well-selection process, including criteria used and their order of application.

Map(s) and site description(s) that clearly indicate the location of the well.

Well and aquifer characteristics that must be entered into the Ground Water Site Inventory

(GWSI) to establish a site file.

To the extent available, additional well and aquifer data that are stored in the Ground Water

Site Inventory.

Site and sampling information required for storage of sample analyses in the Water-Quality

data base (QWDATA).

Written permission of the well owner to measure the water level or sample the well, and to

release the data.

Land-use/land-cover near the well for each well sampled. The form is updated each time a well

is sampled if changes in land use/land cover are observed.

A series of photographs of each well that is sampled and of its surrounding area. The photographs serve as a record of the local land use and help locate the well and water-level measuring

point in the future.

Other information, as available, about the well, such as that listed on the well-information

check list.

Additional Criteria That Apply For Study-Unit Surveys

Existing water-supply, observation, or monitoring wells are selected.

Wells are selected for sampling in a subunit using a grid-based random selection approach

(Scott, 1990; Alley, 1993).

Additional Criteria Recommended For Study-Unit Surveys

Select only observation, monitoring, or low-capacity water-supply wells to avoid the complexities of determining contributing areas to high-capacity wells (such wells can draw water from

units other than the unit of interest).

Well-casing material is Polyvinyl Chloride (PVC) or stainless steel.

Wells that are constructed of PVC have threaded, not glued, joints.

Well screens are continuous-slot wire-wound screens or machine-slotted casing made of PVC or

stainless steel.

 Table 3. Selection, design, and documentation criteria for wells used in National Water-Quality

 Assessment Program Study-Unit Surveys, Land-Use Studies, and Flowpath Studies--Continued
11

1Usually determined by field measurements of well depth and borehole logs describing the depth

to the top and bottom of each open interval; the depths of the hydrogeologic unit(s) at the well; and

checks on the integrity of well construction provided by borehole-geophysical logs, the continuous

pumping of sediment, and slug injection, pressure or partial vacuum tests.

2Usually determined using information on well construction and installation, including the materials used for the casing and screen, screen type, length and dimensions, the methods used to drill, complete, and develop the well, and, if applicable, the type and operation of the pump installed in the well.

3It might not be possible to always meet these criteria unless wells are installed.

Additional Criteria That Apply For Land-Use Studies

Sampling locations are randomly distributed throughout the occurrence of the land-use setting

(combination of land-use and hydrogeologic setting) of interest. Sampling locations are

selected where land use has been stable over the past decade.

With the exception of reference wells, only wells located in recharge areas underlying or

immediately downgradient from the land use of interest are selected.

Install wells: Wells must be installed for urban Land-Use Studies that begin after 1995. For

other Land-Use Studies, existing wells might be selected, but only if the Land-Use Study

objective (table 1) can be met by sampling those wells. If existing wells are selected, select

observation, monitoring, or low-capacity water-supply wells to avoid the complexities of

determining contributing areas to high-discharge wells (such wells can draw water from units

other than the unit of interest).

Wells that are constructed of PVC have threaded, not glued, joints.

Wells have short open intervals, generally 10 feet or less in length.

Additional Criteria Recommended For Land-Use Studies3

Well-casing material is Polyvinyl Chloride (PVC) or stainless steel.

Well screens are continuous-slot wire-wound screens or machine-slotted casing made of PVC

or stainless steel.

Additional Criteria That Apply For Flowpath Studies

Install wells.

Well-casing material is Polyvinyl Chloride (PVC) or stainless steel.

Wells that are constructed of PVC have threaded, not glued, joints.

Well screens are continuous-slot wire-wound screens or machine-slotted casing made of PVC

or stainless steel.

Wells have short open intervals, generally ranging from 1 to 5 feet in length.

 Table 3. Selection, design, and documentation criteria for wells used in National Water-Quality

 Assessment Program Study-Unit Surveys, Land-Use Studies, and Flowpath Studies--Continued
12

As an economical alternative to installing wells, existing monitoring, observation, or

water-supply wells can be selected for Study-Unit Surveys, and in some cases for Land-Use

Studies and Flowpath Studies. If the entire well network consists of water-supply wells, this can

lead to bias in ground-water-quality data. Different types of water-supply wells are likely to lead

to different biases (Alley, 1993). Study Units need to consider the bias introduced by the wellselection process. When selecting water-supply wells, well-construction materials, the design of

the well, and the method of well installation should be determined. Certain materials, well design, or installation methods can result in the well being unsuitable for either water-level measurements or the sampling of targeted water-quality constituents. For example, organic

compounds, such as tetrahydrofuran, methylethylketone, methylisobutylketone, and cyclohexanone can leach from the glue used to bond unthreaded polyvinylchloride casing. Bias also can

result from how the well is operated; the location of the well; the depths of screened intervals

and depth of well completion; well-construction materials; and the type, construction, and age of

a permanently installed pump.

Well construction and the length and depth of well screen(s) are critical factors in well

selection. Measurement of hydraulic head is important. It is difficult to determine the hydraulic

head attributable to each water-bearing unit and the source of water to a well that is screened in

several units, contains multiple screens in different units, or has a long well screen. Wellbore

flow, which can occur in wells having long or multiple screens, can cause mixing of waters of

different quality. On the other hand, wells with screens that are short in comparison to the total

thickness of an aquifer might be screened in intervals that miss major zones of interest, such as

zones of high transmissivity or zones of contamination. In general, selecting several wells in

proximity that differ in well-screen depth but that each have short screened intervals generally is

the preferred means of obtaining depth-averaged water-quality data. Alternatively, a well that is

otherwise suitable but with multiple screens can be used if the appropriate screened intervals can

be isolated for sampling, for example by using packers.

The well pump also can affect the chemistry of a water-quality sample. Consequently, the

type of pump, and the pump and pump-riser-pipe materials are important information to consider

during the selection process. For example, oil can leak from the pump casing and contaminate

water coming in contact with the pump. Suction-lift pumps can induce loss of oxygen and volatilization of some organic compounds from a sample during withdrawal because of the drop in

pressure in the sample line caused by vacuum. Jet pumps use circulation water pumped through

a venturi to carry water to the surface. Both the mixing of circulation water with sample water,

and the drop in pressure of the circulation water across the venturi can affect sample-water quality. Because of the above, for existing wells with pumps, only those with submersible pumps

are selected. Wells with water-lubricated pumps are selected in preference to wells with oillubricated pumps.

The accessibility of a sampling point at a well is an important selection criteria, particularly

when sampling for volatile organic compounds or trace elements. Many water-supply wells will

have an access point for sampling; however, if the only access point is located after an on-site

treatment system, a pressure tank, or a holding tank, these systems could change the chemistry

of the water sample. At wells where an access point close to the well is not available, it is sometimes possible to have a valve installed at the well head for sample collection.
13

Oil, grease, and other foreign materials on drilling and associated equipment can be introduced to water-bearing units during drilling, well completion, and well development if not

removed from equipment prior to its use. This potential for contamination needs to be considered when gathering and interpreting information about candidate wells.

Selection of low-capacity rather than high-capacity wells is recommended for Study-Unit

Surveys, and generally is required for wells selected for Land-Use and Flowpath Studies.

Evaluating if a well has a low or high capacity involves consideration of the effect of the pumping rate on the aquifer in addition to consideration of the pumping rate. For example, pumping

a few tens of gallons per minute from a well screened in a poorly transmissive aquifer might

induce significant leakage from or through confining beds, whereas pumping a few thousands

of gallons per minute from a well screened in a highly transmissive aquifer might not. Pumping

rates of domestic wells generally are low, whereas pumping rates of municipal, commercial/

industrial, and irrigation wells generally are high. Each has several advantages and disadvantages (table 4) to consider when selecting wells for study components.

Well Inventory

The inventory process is used to collect and document all relevant information needed to

select wells for use in data collection and begin creating site files for the wells selected. This

information is gathered from records and site visits. The basic information compiled for a well

inventory is that which is needed to create a Ground-Water Site Inventory file (see “Documentation”) and that which is needed to complete a Well Inventory Form (fig. 1). The inventory

also includes gathering any information identified as necessary to evaluate the well with respect to well-selection criteria (table 3). Written permission must be obtained to gain site

access and to collect and publish data from currently used or abandoned (fig. 2) wells.

Information from records is used to start the well inventory. In addition to the GWSI and

well inventory forms, any available records of well installation and development, well maintenance, geophysical logs and surveys, aquifer tests, geological and geochemical data, and land

use are compiled, reviewed, and incorporated into the well site file.

Site visits to candidate wells are useful to obtain permission to measure or sample the

candidate well, and field verify information about the well. On-site evaluation will help to ensure that data from that well will meet study-component objectives. Well-inventory visits prior

to sampling might seem impractical, particularly on a large scale for the Study-Unit Surveys,

but field verification prior to sampling can save time, money, and effort in the long run. During

the inventory visit, well identification and location are verified, along with access to the site,

to the well, and to the apertures needed for making measurements and collecting samples. A

site sketch indicating well location, surface-water bodies, and major landmarks is drawn. Well

depth and depth to water are measured. Potential point and nonpoint sources of ground-water

contamination are identified. During the inventory visit(s), it is recommended that Study Units

schedule collection of preliminary data to help plan for sample collection, such as purge volume and purge time, routine field measurements (for example, pH, conductivity, dissolved

oxygen), and any appropriate analyte screening (for example, for VOCs).
14

Table 4. Advantages and disadvantages of high-capacity and low-capacity water-supply wells for

water-quality studies (modified from Alan Welch, U.S. Geological Survey, written commun.,

1992)

____________________________________________________________________________

HIGH-CAPACITY WATER-SUPPLY WELLS

____________________________________________________________________________

Advantages:

- Documentation of well construction commonly is good.

- High-capacity wells generally are well developed and frequently purged.

- Long-term access may be possible, particularly for municipal wells.

- High-capacity wells generally provide a larger vertical mix of water in an aquifer or aquifer

system than lower-capacity wells, and thus can provide a more integrated measure of regional

ground-water quality than low-capacity wells.

- Much of the water produced for irrigation and municipal use is from high-capacity wells,

allowing a direct sample of the used resource.

- Long-term water-quality data may be available.

Disadvantages:

- High-capacity wells may not have flow-rate controls and a sampling point near the well

head. Sample collection at high flow rates can be difficult. Losses of VOCs are possible.

- Pumping schedules could be irregular: for example, irrigation wells generally are pumped

seasonally, and could lead to seasonal variations in water quality that actually are an artifact

of the pumping regime.

- The well might have a long vertical gravel pack, or open intervals might span more than one

aquifer or aquifer system.

- Wells with high pumping rates can draw water from water-bearing units other than those

screened, even if the well is screened solely within one unit; thus, the vertical integration of

water from water-bearing units might be unknown.

- Local hydraulics may be atypical of regional ground-water movement as a result of compaction or enhanced downward flow.

- Municipal wells that produce water not meeting water-quality standards are usually abandoned, implying that the remaining population of municipal wells is biased toward acceptable

water quality.

- Downhole chlorination may affect water quality.

- Depth-dependent differences in water quality could be lost, given water sampled could reflect

a mixture of water obtained at different depths.

- Irrigation wells without antisiphon devices that are used for chemigation can lead to groundwater contamination.

- Pump oil can cause local downhole contamination.
15

Table 4. Advantages and disadvantages of high-capacity and low-capacity water-supply wells

for water-quality studies (modified from Alan Welch, U.S. Geological Survey, written commun.,

1992)--Continued

___________________________________________________________________________

LOW-CAPACITY WATER-SUPPLY WELLS

___________________________________________________________________________

Advantages:

- Domestic wells are a major source of drinking-water supply for rural population, so wells

reflect this resource use.

- Good to excellent areal and depth coverage in some areas, particularly for water-table

aquifers.

- Low-capacity pumping rates limit withdrawal of water from water-bearing formations other

than those screened.

Disadvantages:

- Domestic wells may not be available in urban and suburban areas.

- Documentation of well-construction characteristics may be poor or unavailable.

- Well construction, pressure tanks and treatment, and/or pumps may preclude being able to

collect a sample at the well head.

- Downhole chlorination may affect water quality.

- The relation between well locations, septic systems, and other potential processes that could

affect ground-water quality must be established in order to correctly assess what conditions

water-quality data truly reflect.

___________________________________________________________________________
16

WELL INVENTORY FORM Send results of drilling/sampling to owner? Y N

NAWQA Study Unit: ___________________________________ County: _____________________________

Recorded By:___________________ Date: ___________ Time: _________ Photo # ________ Roll # ______

Quad sheet: ________________ Contour interval__________(ft) Scale:___________ Year revised:________

Sources of data: _____________________________________________________________________________

WELL SITE INFORMATION

Site ID (C1): _________________________ Station name (C12): ____________________________________

Lat (C9):_____________ Long (C10):______________ Land-surface altitude (C16):____________ft NGVD

Site accessible to vehicles? YES___ NO ___ Remarks____________________________________________

Use of site (C23)_________; Use of water (C24): 1st________ 2nd________ 3rd________

OWNER INFORMATION

Well Owner Name (C161): _________________________ Phone: (H) _____________(W)______________

Address: _________________________________________________________________________

_____________________________________________ Zip:________________________

Tenant: ____________________________________________ Phone: ______________________

Address: _ ________________________________________________________________________

____________________________________________ Zip: ________________________

Previous owner: ____________________________________________________________________

Permission given by: ________________________________________________________________

Permission to remeasure/sample/drill: YES____ NO____ CALL____ STOP BY____ OK IF NOT THERE____

Dates not available: ________________________________________________________________________

Owner: interested_____ neutral_____ not interested_____ Remarks________________________________

SITE CHARACTERISTICS (When well sampled, Land-Use Land-Cover form must also be filled out)

Land use: Urban___ Suburban___ Rural___ Crop___ Pasture___ Natural___ Other___________________

Potential contamination sources near well (septic systems, barnyard, feedlot, pasture, nearby fertilized fields,

local storage of chemicals, other):_________________________ None visible___________________

Domestic wastes to: Septic tank___ Sewer___ Other_______________________________________

Figure 1. Example of a well-inventory form for the National Water-Quality Assessment Program.
17

WELL INSTALLATION AND CONSTRUCTION

Method of well completion: Primary filter pack______; Secondary filter pack______

Type of annular seal__________________; Type of surface seal (C67);________________;

Protective casing____ (locked___, unlocked___)

Method of well installation (C65):_________________ Type of finish (C66):_______________________

Date well constructed (C21):_________________ Driller:______________________________________

Depth of well (C28):_________ft Depth to bottom of casing (C74):___________ft

Casing diameter (C79):_________ in. Casing material (C80):_________

If PVC used in construction, was glue used? YES_____ NO_____ Remarks __________________________

Primary aquifer (C714) _____ Source of information: geology map, topo map, outcrop, drilling log, other _____

Method of well development (C69):____________________________________________________________

Well-construction integrity checks: Date(s)_______________________ Type:_________________________

Pump Type:_____________________ HP:__________ Capacity:______________________________

Pumping during normal use (if data available)

Approximate frequency (daily, monthly, yearly) ___________________

Approximate pumping rate (gpm): Range ____________________ Mean ___________________

Approximate duration (min, hrs): Range _____________________ Mean ___________________

Comments:_________________________________________________________________________________

__________________________________________________________________________________________

WATER LEVEL

Hold_______________ Hold_______________ Hold_______________

Cut________________ Cut________________ Cut ________________

= _________________ = _________________ = __________________

+/-mp_____________ +/-mp______________ +/-mp_______________

Water level, in ft below

 LS (C30 or C237) ______________ ______________ _______________

Water-level status (C238): ____________________________________________

Figure 1. Example of a well-inventory form for the National Water-Quality Assessment Program--Continued.
18

SAMPLING INFORMATION

1. Can water level be measured? YES___ NO___ Why not?_______________________

2. Can well be sampled? YES___ NO___ Why not?_____________________________

3. Sampling tap location: upstream from a holding tank? _____ pressure tank? _____

 If yes, give size of tank _________ gal

4. Any water treatment upstream from sampling point? YES ___ NO ___ If yes, describe: _______________

5. Other notable well features, if any (pitless adapter, frost pit, missing or leaky cap, well house, chemicals

 stored near well): _________________________________________________________________________

6. Water Quality? Taste:______ Odor:______ Color:______ Remarks:______________________________

7. Minimum rate at which pump in well can be operated: ________________gal/min

WATER-QUALITY FIELD MEASUREMENTS

Location of sampling point____________________________________________________________

00010 Temperature _______oC 00095 Specific Electrical Conductance __________μS/cm

00400 pH _____________ 00300 Dissolved oxygen ___________mg/L 00076 Turbidity___________NTU

Other _______________________

AVAILABILITY OF ADDITIONAL INFORMATION (refer to Well Information Check List

(see Installation) and include in inventory file):

1. Water-level records? YES___ NO___ Remarks:_______________________________________________

2. Pumping records? YES___ NO___ Remarks:_________________________________________________

3. Water-chemistry records? YES___ NO___ Remarks:___________________________________________

4. Borehole geophysical logs? YES___ NO___ Type:_____________________________________________

5. Surface geophysical surveys? YES___ NO___ Type:___________________________________________

6. Aquifer tests? YES___ NO___ Type:________________________________________________________

7. Geologic materials samples? YES___ NO___ Type:____________________________________________

8. Land-use records for well vicinity (for example, pesticide and fertilizer application rates):

REMARKS, SITE SKETCH, AND WELL-HEAD SKETCH (showing locations of sampling point,

holding tanks, and so forth) (Township____________ Range________ Section_______Quarter______):

Figure 1. Example of a well-inventory form for the National Water-Quality Assessment Program--Continued.
19

AGREEMENT FOR USE OF

ABANDONED TEST HOLE OR WELL

THIS AGREEMENT is entered into this ____________ day of _________________,

19____, by and between _____________________________________________________

hereinafter called “Licensor,” and the United States of America, by and through the

U.S. Geological Survey, U.S. Department of the Interior, hereinafter called “Licensee,”

pursuant to the Act of December 24, 1942, as amended (43 U.S.C. Sec. 36b).

WITNESSETH:

1. Licensor, for and in consideration of the faithful performance by Licensee of all

covenants and conditions herein contained and payment of the amount hereinafter provided,

hereby consents and agrees to the exclusive use of the abandoned test hole or well for the

collection of geohydrologic data in the interval from the land surface to a depth of _____ feet.

2. The said test hole or well is located and described as follows: (name, location and

description) _________________________________________________________________

___________________________________________________________________________

.

3. This agreement is valid only upon the condition that the landowner, estate, or

proper authority grants the right of ingress to and egress from the said test hole or well and

surrounding work area.

4. This agreement is valid only upon the condition that the (state plugging regulatory

agency) ____________________________________________________________________

has accepted the plugging requirements agreed upon by the Licensor and Licensee.

5. The Licensor will complete all plugging required by the state plugging authority

up to and including a cement plug in the bottom of the surface casing. No plugs would be

set in the surface casing between the bottom plug and the surface, and a metal cap would

be installed on the top of the casing.

6. Use of the test hole or well by the Licensee shall begin after __________ days of

a mutually agreeable time after the effective date of this agreement.

7. As consideration for the rights and privileges granted herein, the Licensee shall

pay to the Licensor the sum of $_______________ upon presentation of bill therefore,

subject to the availability of appropriations by the Congress.

8. The Licensee can cannot (cross out the one that does not apply) deposit in the mud

pit(s) the drilling fluid removed from the test hole or well after the Licensor has ceased all

drilling and associated operations and abandoned the drill site except for restoring the site

to as nearly as possible the same condition existing prior to drilling or to a condition agreed

upon by the landowner, estate, or proper authority.

Figure 2. Form for agreement for use of abandoned test hole or well.
20

9. The test hole or well will be plugged by the Licensee at its own cost and expense

and as required by the state plugging authority after the expiration of this agreement or any

renewal thereof unless the Licensor takes over the test hole or well as it is for its use. After

plugging, the test hole or well site shall be restored by the Licensee to as nearly as possible

the same state and condition existing prior to drilling of the test hole or well, or to a condition

agreed upon by the Licensor and/or landowner, estate, or proper authority.

10. The Licensee agrees to cooperate, to the extent allowed by law, in the submittal of

all claims for alleged loss, injuries, or damages to persons or property arising from the acts

of Licensee’s employees, acting within the scope of their employment, in the use or plugging

of the test hole or well pursuant to the Federal Tort Claims Act (28 U.S.C. 2671 et seq.).

11. This agreement shall become effective on the day and year first above written,

and shall continue in full force and effect until terminated by Licensee at any time on 30

days written notice, or ________________________________________________________.

12. No Member of or Delegate to Congress or Resident Commissioner after his

election or appointment, either before or after he has qualified and during his continuance

in office, and no officer, agent, or employee of the Government, shall be admitted to any

share of this agreement, or to any benefit arising therefrom, but this provision shall not be

constructed to extent to this agreement if made with a corporation for its general benefit.

13. The Licensor warrants that he has not employed any person to solicit or secure

this contract upon any agreement for a commission, percentage, brokerage, or contingent

fee. Breach of this warranty shall give the Licensee the right to terminate the agreement, or,

in its discretion, to deduct from the agreement amount or consideration the amount of such

commission, percentage, brokerage, or contingent fees. This warranty shall not apply to

commissions payable by Licensor upon agreements secured or made through bona fide

established commercial or selling agencies maintained by the Licensor for the purpose of

securing business.

14. This agreement shall inure to the benefit of and be binding upon the successors,

assigns, and transferees of the parties hereto, including successors of the Licensee in

control of the project or the portion thereof affected by this agreement.

IN WITNESS WHEREOF, the parties have caused these presents to be executed

the day and year first above written.

LICENSOR: LICENSEE:

NAME_________________________________UNITED STATES OF AMERICA

DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY:

ADDRESS______________________________By________________________________

 ______________________________________ Title_______________________________

 ______________________________________ APPROVED:

By_______________________________

District Chief

Water Resources Division

Figure 2. Form for agreement for use of abandoned test hole or well--Continued.
21

In some cases, it may not be possible to locate a well in the area of interest that meets all

of the well-selection criteria for a study component and installation of a new well is not an

option. In these cases, one option is to use an existing well that does not meet all the selection

criteria, with the knowledge that the results might be biased in some way. Another option is

to reduce the scope of the Study-Unit Investigation. In this case, discussion with appropriate

NAWQA Regional, Headquarters, and National Synthesis staff is required.

The field verification includes checking the construction integrity of the wells being considered for selection. Checking construction integrity helps evaluate if there is a good hydraulic connection between the well screen and the aquifer and whether or not the well screen and

casing are damaged. At a minimum, this includes a depth-to-bottom measurement in the well,

if possible. USGS standard procedure is to check the depth to well bottom annually or the next

time the well is visited for data collection if that occurs less than annually (USGS, 1980). Other

means of testing well integrity include the use of borehole-geophysical logs, comparison of

water-level fluctuations over time, and periodic determination of barometric efficiency, and

short-term slug, injection, pressure or partial vacuum tests (W. Lapham, U.S. Geological

Survey, written commun., 1995--see footnote 1; Bedinger and Reed, 1988; Driscoll, 1986;

U.S. Geological Survey, 1980; Lohman, 1972; and Stallman, 1971). Well-integrity tests

should not be limited to a well-inventory site visit. If run periodically, well-integrity tests can

indicate changes in well response that might be attributable to changes in well-construction

integrity.

Monitoring wells that are selected by the NAWQA Study Unit must be constructed to

meet the specific objectives (table 1), water-quality-data requirements (table 2), and welldesign criteria (table 3) of that study component.

Well Installation

Requirements for selection of wells for NAWQA Land-Use Studies and Flowpath Studies are sufficiently restrictive that wells meeting those requirements generally will not be available. Consequently, some wells will need to be installed. Before wells are installed it is

important to take the following steps: (1) make site visits to assess conditions; (2) acquire the

necessary well-drilling permits and approvals from site owners and Federal, State, and local

regulatory authorities (figs. 2 and 3); and (3) obtain utility right-of-ways.

Well installation requires: (1) preparation, (2) well drilling, (3) well completion, and (4)

well development. Overall, it is important to recognize that the intended use of the well largely

dictates the possible choices of methods and materials used during each of these steps.

Preparation

Factors considered for well installation include the nature of materials that make up and

overlie the aquifer (for example, unconsolidated or consolidated materials; if consolidated materials are fractured or have openings caused by dissolution); the depth to water, to the top of

the aquifer of interest, and to the zone in the aquifer to be monitored; the type of drilling equipment available; access to the site; well casing and screen materials, length, and diameter, and
22

Form 9-1483 Agreement Number:__________________

(Aug. 1994)

AGREEMENT FOR INSTALLATION, MAINTENANCE AND

USE OF A TEST HOLE AND/OR OBSERVATION WELL ON

 PRIVATE OR _____________________________ PROPERTY

THIS AGREEMENT is entered into this ___________ day of ____________, 19____, by and between

__________________________________________________, hereinafter called “Licensor,” and the United States of

America, by and through the U.S. Geological Survey, U.S. Department of the Interior, hereinafter called “Licensee,”

pursuant to the Act of December 24, 1942, as amended (43 U.S.C. sec. 36b).

WITNESSETH:

1. Licensor, for and in consideration of the faithful performance by Licensee of all covenants and conditions

herein contained and payment of the amount hereinafter provided, hereby consents and agrees to the excavation,

installation, maintenance, and exclusive use of (describe physical characteristics of hole and/or well, maintenance

facilities, and purposes of excavation, use and maintenance.)

_____________________________________________________________________________________________

_____________________________________________________________________________________________

_____________________________________________________________________________________________

hereinafter collectively referred to as “Structure,” by the Licensee upon and over the property of the Licensor as

described in Paragraph 2 hereof, and the Licensor grants the right of ingress to and egress from the said Structure

and property described herein for the purpose stated herein.

 This test hole is an opening which extends into the earth and is produced by drilling or augering methods.

 This observation well is a hole which extends into the earth and is produced by drilling or augering, which

may or may not be cased or screened, and exists solely for the purpose of obtaining geologic and hydrologic

information.

2. The said Structure shall be located on the property of Licensor as shown on attached drawing and further

described as follows: (site location) _______________________________________________________________

____________________________________________________________________________________________

3. Excavation and/or installation of said structure shall begin within ______ days or a mutually agreeable time

after the effective date of this agreement. The said Structure and appurtenances thereof shall be excavated, installed

and maintained in a good, safe, diligent and workmanlike manner.

4. The said Structure and appurtenances and all equipment and tools for the maintenance and use thereof placed

in or upon said described property shall remain the property of the Licensee and shall be removed, filled and/or

plugged, etc., by the Licensee at its own cost and expense within a reasonable time after the expiration of this agreement or any renewal thereof. Upon removal, filling and/or plugging, etc. of said Structure and appurtenances the

Licensee shall restore said property to, as nearly as possible, the same state and condition existing prior to the

excavation, and/or installation of said Structure and its appurtenances.

5. The Licensee agrees to cooperate, to the extent by law, in the submittal of all claims for alleged loss, injuries,

or damages to persons or property arising from the acts of Licensee’s employees, acting within the scope of their

employment, in the excavation, installation, use, maintenance, and/or removal of said Structure appurtenances, equipment and tools pursuant to the Federal Tort Claims Act (28 U.S.C., 2671 et seq.)

Figure 3. Sample of Form 9-1483 (Aug. 1994), “Agreement for Installation, Maintenance and Use of a Test Hole

and/or Observation Well on Private or _____ Property.” (Available from GSA, National Forms Center, Warehouse

4, Dock 1, 4900 South Hemphill St., Ft. Worth, TX 76115 and as a FrameMaker template. Sample form not a binding document.)
23

(2)

6. As consideration for the rights and privileges granted herein, the Licensee shall pay to the Licensor the

sum of $______________ upon presentation of bill therefore, subject to the availability of appropriations by the

Congress.

7. This agreement shall become effective on the day and year first above written, and shall continue in full

force and effect until terminated by Licensee at any time on 30 days written notice.

8. No Member of, or Delegate to, Congress or Resident Commissioner after his election or appointment,

either before or after he has qualified and during his continuance in office, and no officer, agent, or employee of the

Government, shall be admitted to any share of this agreement, or to any benefit arising therefrom, but this provision

shall not be construed to extend to this agreement if made with a corporation for its general benefit.

9. The Licensor warrants that he has not employed any person to solicit or secure this contract upon any

agreement for a commission, percentage, brokerage or contingent fee. Breach of this warranty shall give the Licensee the right to terminate the agreement, or, in its discretion, to deduct from the agreement amount or consideration the amount of such commission, percentage, brokerage, or contingent fees. This warranty shall not apply to

commissions payable by Licensor upon agreements secured or made through bona fide established commercial or

selling agencies maintained by the Licensor for the purpose of securing business.

10. This agreement shall inure to the benefit of, and be binding upon, the successors, assigns, and transferees

of the parties hereto, including successors of the Licensee in control of the project or the portion thereof affected by

this agreement.

IN WITNESS WHEREOF, the parties have caused this agreement to be executed the day and year first

above written.

LICENSOR: LICENSEE:

NAME__________________________________ UNITED STATES OF AMERICA

DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY:

ADDRESS_______________________________ By__________________________________

 ________________________________ Title_________________________________

APPROVED:

By________________________________

District Chief

Water Resources Division

Figure 3. Sample of Form 9-1483 (Aug. 1994), “Agreement for Installation, Maintenance and Use of a Test Hole

and/or Observation Well on Private or _____ Property.” (Available from GSA, National Forms Center, Warehouse 4, Dock 1, 4900 South Hemphill St., Ft. Worth, TX 76115 and as a FrameMaker template. Sample form

not a binding document.)--Continued.
24

Figure 4. General design of a monitoring well in unconsolidated deposits for National WaterQuality Assessment Program Land-Use and Flowpath Studies.

        

 







Vented locking

protective cover

Cement surface

seal

Not to scale

Annular seals

Secondary filter

pack

Primary filter

pack

Plate bottom

Well screen

Aquifer

Protective casing
25

cost. In unconsolidated deposits, a common monitoring-well design (fig. 4) consists of a well

screen and casing installed in a well bore with an annular space backfilled with filter packs and

annular and surface seals. Specific aspects of NAWQA-design monitoring wells, however,

can vary depending on requirements to meet specific data-collection objectives, site conditions

encountered, and the drilling method used. For example, some Flowpath Studies will include

investigation of ground-water quality as ground-water discharges to surface water, which

might require installation of streambed piezometers that are steel, wire-wound well screens

attached to the bottom of steel casing that are hand driven to the desired depth into the aquifer

beneath the stream. In another situation, an aquifer might contain fine-grained sediment,

which in order to prevent silting in of the screen, would require attachment of a riser pipe to

the bottom of the well screen to serve as a collection area.

Study Units that select or install wells in semiconsolidated deposits and rock must ensure

that the wells meet the design criteria for the study component (table 3). Three possible designs consist of (1) an open borehole at the interval of interest, with well casing installed in the

borehole above this interval (the annular spacing between the casing and borehole wall is

sealed with grout) (fig. 5a); packers installed in the open borehole above and below the interval

of interest to isolate part of the borehole for water-quality sampling (fig. 5b); or a well screen

with filter pack installed at the interval of interest, with an annular seal installed above this interval (fig. 5c). Generally, all three of these designs meet the design criteria for Land-Use and

Flowpath Studies (table 3) but have advantages and disadvantages that must be evaluated when

selecting one of these three designs, a modification of one of these designs, or an alternative

design (W. Lapham, U.S. Geological Survey, written commun., 1995--see footnote 1).

For Flowpath Studies, clusters of monitoring wells usually will be installed. Clusters of

monitoring wells are used when one well is considered inadequate in terms of characterizing

the vertical distribution of hydraulic head or water quality. Several designs of well clusters

suitable for water-level measurements and water-quality sampling are illustrated in figure 6

and include (1) monitoring wells with short screens, each installed in its own borehole (fig. 6a);

(2) multiple monitoring wells, each with a short screen, installed in a single borehole, with an

annular seal between each screened interval (fig. 6b); and (3) a single well, which contains a

series of multiport samplers, installed in a single borehole, with each port separated by an

annular seal, or by a packer (fig. 6c). The decision to use one design over another depends on

a number of factors related to the objective of the Flowpath Study; the advantages of given

well-cluster designs are discussed in another document (W. Lapham, U.S. Geological Survey,

written commun., 1995--see footnote 1), and their use is described in greater detail in Jelinski

(1990); LeBlanc and others (1991); Stites and Chambers (1991); Pickens and others (1978).

Short-screened wells installed in separate boreholes (fig. 6a) is the design recommended for

NAWQA studies. Spacing wells about 5 to 10 ft apart in a cluster generally maintains well

integrity without comprising the intent of collecting data at a well cluster.
26





Land surface

Well casing

and annular

seal

Well casing

Semiconsolidated

deposits or rock

Open

borehole Packer

Screened or open

interval isolated

by packers

Well

screen

Filter

packs

(a) Open borehole (b) Packers in borehole (c) Well screen in borehole

Annular seal

Unconsolidated

sediments

Pipe assembly

 for packers

Figure 5. Examples of monitoring-well designs in semiconsolidated deposits and in rock.
27

 Figure 6. Examples of three well-cluster designs.















Well 

screen

Filter

pack

Annular

seal

Annular

seal

Multiport

sampler

(a) Monitoring wells with short

screens, each installed

in its own borehole

 

(b) Multiple monitoring wells

with short screens installed

in a single borehole 

(c) A series of multiport samplers

installed in a single borehole
28

It is important to select the appropriate materials, and type, diameter, and length of casing

and screen, as these can affect the quality of a ground-water sample. Biased water-quality data

can arise from chemical and physical interaction between ground water and materials used to

construct monitoring wells (tables 5 and 6). These biases can result from leaching, sorption/

desorption, or volatilization. Leaching and sorption/desorption studies that examined casing

materials are described by Hewitt (1994a and b, 1992); Parker and Ranney (1994); Ranney and

Parker (1994); Parker, Hewitt, and Jenkins (1990); Parker and Jenkins (1986); Gillham and

O’Hannesin (1990); Reynolds and others (1990); Reynolds and Gillham (1986); Cowgill (1988);

Barcelona and others (1983); Sosebee and others (1983); and Curran and Tomson (1983). Parker

(1992) provides a recent summary of the findings of several of these and other studies.

The well screen potentially can alter water quality because of the large surface area exposed to ground water. The screen is the part of the monitoring well most susceptible to corrosion and (or) chemical degradation, and provides the highest potential for sorption or leaching of

contaminants (Aller and others, 1989, p. 192). Thus, when selecting the screen materials, resistance to leaching or sorption/desorption for the broad suite of NAWQA constituents is a major

consideration (table 5). Therefore, PVC is the material of choice for well casing screens installed

for NAWQA ground-water studies. In cases where the well will be used only for sampling one

class of chemical constituents, casing and screen materials can be selected to minimize bias

caused by that material (table 5).

The PVC casing selected should be National Sanitary Foundation-approved schedule 40

(or 80) and flush jointed and threaded. In low-yielding materials, such as till and loess, leakage

of water through improperly sealed PVC joints can contribute a significant amount of water to a

well compared to the amount of water contributed through the well screen (van der Kamp and

Keller, 1993). Under such circumstances, O-rings or Teflon tape on threaded joints below the

water table helps prevent this leakage, as does a properly installed annular seal.

Joints of PVC or other plastic casing used for NAWQA-installed wells must be threaded

and not glued. Organic compounds that leach from PVC primer or adhesive can compromise

sample integrity (Sosebee and others, 1983). Compounds listed as ingredients in one or more of

six PVC adhesives and one primer included THF (tetrahydrofuran), MEK (2-butanone or methylethylketone), MIBK (methylisobutylketone), cyclohexanone, and DMF (N, N-dimethylformamide). In addition to sample contamination, such compounds can mask or made the identification of other VOCs difficult by co-eluting with other VOCs during sample analysis.

The length of a well screen is determined on the basis of the scale and objectives of the

investigation. The length of a well screen is important in relation to the vertical interval of investigation. In terms of water-level and water-quality measurements, a short screen generally

provides measurements of hydraulic head and ground-water quality that more closely represent

point measurements in the aquifer than measurements provided by a long screen. Ground-waterquality samples also reflect an integrated measurement of water quality vertically throughout the

screened (or open) interval. Pumping a well with a long screen is more likely to induce mixing

of waters of different chemistry than pumping the same well with a short screen. Thus, concentrations of constituents in samples obtained from wells with long screens are less likely to reflect

the maximum concentrations of those constituents at any point within the screened interval than

samples obtained from wells with short screens.
29

a

Includes constituents to be analyzed according to the laboratory schedules shown on

table 2.

bPTFE can be highly sorptive of some organic compounds, although these losses might

diminish as equilibrium of casing with ground water is approached (Parker and Ranney,

1994; Ranney and Parker, 1994).

c

PVC is the best compromise choice if measuring all constituent classes in table 2.

dVolatile organic compounds leached from glue can include THF (tetrahydrofuran),

MEK (methylethylketone), MIBK (methylisobutylketone) and cyclohexanone (Sosebee and

others, 1983).

e

Generally, stainless steel 316 is more resistant to corrosion than stainless steel 304.

Table 5. Relative leaching or sorption/desorption ranking of well-casing and screen materials

for indicated water-quality constituent classes

[Applies in general to classes of compounds indicated. Actual amounts and rates of leaching

or sorption/desorption of individual constituents can differ within each major constituent class.

The tendency of a material to leach compounds can differ from the ability of the materials to

sorb constituents or compounds. 1, least leaching or sorptive/desorptive; 5, most leaching or

sorptive/desorptive; PTFE, polytetrafluoroethylene; PVC, polyvinylchloride]

Water-quality constituent classa

Material

Inorganic

constituents

Organic

compounds

PTFE 1 2-4b

PVCc

- Flush-threaded joints 1-2 2

- Glued jointsd 3 5

Stainless steele 4 1-2

Galvanized steel 5 4

Carbon steel 5 4
30

Table 6. Some general characteristics of materials used for well casing and screens (modified

from T.E. Imbrigiotta, U.S. Geological Survey, written commun., 1989)

[PTFE, polytetrafluoroethylene; PVC, polyvinylchloride; SS, stainless steel]

PTFEa,b

- Virgin PTFE readily sorbs some organic solutes (Parker and Ranney, 1994).

- Ideal material in corrosive environments where inorganic compounds are of interest.

- Useful where pure product (organic compound) or high concentrations of PVC solvents

exist.

- Potential structural problems because of its low tensile and compressive strengths, low

wear resistance, and the extreme flexibility of the casing string as compared to other

engineering plastics (Driscoll, 1986, table 21.6; Dablow and others, 1988; Aller and

others, 1989, table 25).

- Potential problems with obtaining a seal between the casing and the annular sealant

because of PTFEs low coefficient of friction and antistick properties as compared to

other engineering plastics (Aller and others, 1989, p, 151).

- Maximum string length of 2 inch schedule 40 PTFE casing should not exceed about

375 feet (Nielsen and Schalla, 1991, p. 262).

- Expensive.

PVCa,b

- Leaching of compounds of tin or antimony, which are contained in original heat stabilizers during formulation could occur after long exposure.

- When used in conjunction with glued joints, leaching of volatile organic compounds from

PVC primer and glues, such as THF (tetrahydrofuran), MEK (methylethylketone), MIBK

(methylisobutylketone) and cyclohexanone could leach into ground water. Therefore,

threaded joints below the water table, sealed with o-rings or Teflon tape, are preferred.

- Cannot be used where pure product or high concentrations of a PVC solvent exist.

- Maximum string length of 2 inch threaded PVC casing should not exceed 1,200 to 2,000

feet (Nielsen and Schalla, 1991, p. 250).

- Easy to cut, assemble, and place in the borehole.

- Inexpensive
31

a

Residues, such as threading lubricants used in production or contamination during

shipping, require that all materials be cleaned inside and out prior to installation.

bPossible construction alternative is to use a PTFE screen with threaded PVC casing.

STAINLESS STEELa

- Generally has high corrosion resistance, but varies with type.

- Corrosion can occur under acidic and oxidizing conditions.

- Corrosion products are mostly iron compounds, with some trace elements (see below).

- Primarily two common types:

(1) Stainless steel 304 (SS304): Iron alloyed with the following elements (percentages

approximate): chromium (18-20 percent), nickel (8-11 percent), manganese (2 percent), silicon (0.75 percent), carbon (0.08 percent), phosphorus (0.04 percent), sulfur

(0.03 percent).

(2) Stainless steel 316 (SS316): Iron alloyed with the following elements (percentages

approximate): chromium (16-18 percent), nickel (10-14 percent), manganese (2 percent), molybdenum (2-3 percent), silicon (1 percent), carbon (0.08 percent),

phosphorus (0.04 percent), sulfur (0.03 percent).

- Corrosion resistance is good for SS304 and excellent for SS316.

- Expensive.

GALVANIZED STEELa

- Less corrosion resistance than SS304 or SS316 and more resistance to corrosion than

carbon steel (below).

- Oxide coating could dissolve under chemically reduced conditions releasing zinc and

cadmium.

- Weathered or corroded surfaces present active adsorption sites for organic and inorganic

 constituents.

- Inexpensive.

CARBON STEELa

- Corrosion products (for example, iron and manganese oxides, metal sulfides, and dissolved metal species) can occur.

- Sorption of organic compounds onto metal corrosion products is possible.

- Weathered surfaces present active adsorption sites for organic and inorganic constituents.

- Inexpensive.

Table 6. Some general characteristics of materials used for well casing and screens (modified

from T.E. Imbrigiotta, U.S. Geological Survey, written commun., 1989)--Continued

[PTFE, polytetrafluoroethylene; PVC, polyvinylchloride; SS, stainless steel]
32

Screen lengths for monitoring wells installed by NAWQA for Land-Use and Flowpath

Studies typically should range from 2 to 10 ft. The actual length used should reflect study objectives and aquifer conditions. For example, a screen length of 5 ft might be too long for a well

used in a NAWQA Flowpath Study, if information suggests that marked vertical differences in

the distribution of hydraulic head or water quality occur on the order of a few feet or less. A

5-ft screen placed immediately below the water table, however, probably is appropriate for most

NAWQA Land-Use Studies. As a general rule, screen lengths of 10 ft or less generally are

appropriate for most NAWQA Land-Use Studies and screen lengths of 1 to 5 ft in length generally are appropriate for most NAWQA Flowpath Studies (table 3).

The diameter of monitoring wells for water quality typically range from one-half to 6 in,

with the 2-in diameter well being the USGS and industry norm. Ideally, the preferred wellcasing diameter would be suitable for running aquifer tests as well as for collecting water-quality

data. Typically, wells for an aquifer test consist of one large-diameter pumping well (4-in diameter or greater) that is associated with wells that can be of smaller diameter in which drawdown

is measured as pumping proceeds. The larger diameter normally is required for the pumping well

to ensure that the well can be pumped at a rate sufficient to cause measurable drawdown in the

observation wells. Therefore, a well with small diameter (2 in or less) generally is not suitable

as the pumping well for aquifer testing. The hydraulic data acquired from aquifer tests are particularly important to meet objectives of the Flowpath Studies. Therefore, plans for Flowpath

Studies should include installation of at least one larger diameter well per well cluster along the

flowpath that will be suitable for aquifer testing, if (1) a larger diameter well is needed to obtain

hydraulic data, (2) if a suitable well does not already exist, or (3) if the hydraulic data required

are not available.

It is not always possible to select the optimum construction material and screen design. For

example, for a Flowpath Study of trace-element concentrations in ground water in an area inaccessible to a drill rig, a hand-driven monitoring well constructed of steel casing and drive point

might be the only alternative. The quality of data obtained from such a monitoring well may be

difficult to interpret. Where a less-than-optimum well design is used, the increased risk of data

bias needs to be considered and any potential bias must be explicitly identified, defined, and

reported.

Decontamination of well-installation equipment and materials

Decontamination of well-installation equipment prior to use reduces contamination of drill

holes, aquifers, pore water at the screened interval, and cross-contamination between wells. Procedures for decontamination of equipment, casing and screens, and other materials used for well

installation are provided in table 7 and in greater detail in Aller and others (1989), U.S. Environmental Protection Agency (1987), Moberly (1985), and Richter and Collentine (1983), and in

W. Lapham, U.S. Geological Survey, written commun., 1995--see footnote 1.

Decontamination of equipment and materials and documenting decontamination procedures and quality-control data is to be a standard operating procedure for NAWQA Study Units.

The frequency of decontamination depends on subsurface conditions at the drill site and objectives of the sample collection. Decontamination of equipment between drill sites also is an
33

important precaution to prevent possible cross-contamination between sites. At sites where

well clusters are being installed, decontamination of equipment between drill holes will help

prevent cross-contamination between boreholes. The degree to which each step of the six-step

protocol that follows must be completed, however, depends on the Study-Unit data-collection

requirements, including target contaminants and concentrations in ambient samples; the confidence level needed for the data; and the contaminants expected to be contributed by the

equipment and methods used for installation and completion of the well.

Well Drilling

Selection of a drilling method from among the methods available requires consideration

of the study objectives, as well as site conditions and economics (tables 8 and 9). Because a

primary purpose of installing the wells for NAWQA Land-Use and Flowpath Studies is for

water-quality sampling, a drilling method that has minimal effect on ground-water chemistry

should be a primary consideration during selection of a method.

Table 7. Six-step procedure for decontamination of well-installation equipment and

materials (modified from Aller and others, 1989, p. 62)

1. Select a location for decontamination procedures:

• Avoid spilling decontamination fluids at drilling site;

• Prepare clean area for cleaned equipment.

2. Select equipment requiring decontamination.

3. Determine the frequency of decontamination of the equipment.

4. Select the cleaning technique and type of cleaning solutions to be used for decontamination. The routine procedure for NAWQA for cleaning well-installation equipment and

materials is:

• Wash outside (and inside where applicable--for example, well casing and screen) of

equipment and materials used during well installation using a low-sudsing, nonphosphate detergent;

• Complete decontamination procedure with high-pressure steam cleaning using

potable tap water.

5. Contain residual contaminants and cleaning solutions, if necessary, and dispose according

to regulations.

6. Plan to collect some quality-control samples to evaluate the effectiveness of decontamination procedure (for example, a sample of the rinse water that was used to steam clean or

remove all residues and additional samples of rinse water taken from the equipment after

it has been decontaminated).
34

For installation of wells for sampling ground-water quality, preferred drilling methods are

those that minimize (1) the possibility of contamination of aquifers and aquifer pore water by

foreign drilling fluids, and (2) cross-contamination between aquifers by drilling fluid, pore

water, and drill cuttings. Given that the primary objective of installing wells for NAWQA studies is for water-quality sampling, the selection of a drilling method that minimizes the potential

for subsurface contamination by the drilling process should be of primary concern, and wellinstallation needs should be budgeted accordingly. Use of other drilling methods must be done

with the knowledge that increased time and cost might have to be committed to adequately

develop and purge the well prior to sampling.

In some cases, a method of drilling that minimizes the potential for subsurface contamination by the drilling process might severely limit collection of other data at the well that are also

important to meeting the study-component objectives. For example, many of the most useful

borehole-geophysical logs must be run in uncased, fluid-filled boreholes. This requirement is at

odds with the most preferred methods of drilling for installing wells for water-quality sampling.

Study Units must weigh the cost benefit of data desired against the practical constraints of the

drilling methods being considered and the primary objective of collecting ground-water-quality

samples that accurately represent ground-water chemistry.

Well-construction information must be documented at the time of well installation, as

discussed in the section “Documentation.”

Table 8. Factors to consider when selecting a drilling method (modified from W. E. Teasdale,

U.S. Geological Survey, written commun., 1992)

____________________________________________________________________________________________

Logistical considerations

Accessibility of the drilling site

Ability to obtain permits and approval to drill at the site

Availability of necessary equipment

Time available to complete drilling program

Ease of equipment decontamination at and between sites

Experience of the driller

Drilling considerations

Types and competency of water-bearing units to be drilled and sampled

Types and quality of lithologic and other borehole logs required

Types and quality of aquifer samples required

The importance of minimizing contamination of aquifers by a drilling fluid

The importance of minimizing cross contamination between aquifers

The importance of minimizing disturbance of aquifers during drilling

Total depth of drilling anticipated

Casing diameter and casing material selected for the monitoring well

Ease of completing the monitoring well as designed, for example ease of

 installation of filter pack, grouting, and instrumentation

Economic considerations

Cost of drilling and sampling to meet data needs. ____________________________________________________________________________________________
Table 9. Summary matrix of relations between drilling criteria and drilling methods (modified from W. E. Teasdale, U.S. Geological Survey, written

commun., 1992)[The relations given in this table generally apply; there are exceptions in some cases depending on specific techniques employed during drilling1]

1 Good formation samples obtained only when a sample tube is added to cable tool; otherwise samples are disaggregated.

 CRITERIA

 METHODSHollow-stem augering √ √ √ √ √ √ √ √Solid-stem augering √ √ √ √ √ √ √ √Bucket-augering √ √ √Hand augering √ √ √ √ √ √ √Direct rotary--mud √ √ √ √ √ √Direct rotary--air √ √ √ √ √ √Reverse circulation rotary √ √ √ √ √Cable tool (percussion) √ √ √1 √ √Jet wash and jet percussion

√ √ √ √ √ √ √ √ √

Driven wells (percussion) √ √ √ √ √ √ √ √

Inexpensive

Fast

Excellent mobility

Steel casing required

Drilling fluid required

Limited to shallow depths

Good formation samples

Poor formation samples

No formation samples

Gravel packing or grouting

difficult to impossible

Permits multiple-well

completion in single hole

Can drill in most

types of formations

Possibility of

cross contamination

Limited casing

diameter can be used

35
36

Well Completion

Well completion ensures that the hydraulic head measured in the well is that of the aquifer(s) of interest, ensures that only the aquifer(s) of interest contribute(s) water to the well, and

prevents the annular space from being a vertical conduit for water and contaminants. Such completion steps are critical to the long-term goals of NAWQA, which dictate that many of the wells

installed by the program are to be used for water-quality sampling for decades. Well completion

in unconsolidated deposits for the NAWQA Program consists of installing the well casing and

screen, and filling and sealing the annular space between the well casing and borehole wall, and

completing the documentation required, as discussed on page 43 in the section “Documentation.”

Compliance with State regulations for well completion, as for well drilling, is mandatory.

Specific details of well completion require consideration of several hydrogeologic factors,

including (1) the depth to water, to the top of the aquifer of interest, and to the zone in the aquifer

to be monitored; (2) the nature of materials that make up the aquifer to be monitored and that

overlie the aquifer--for example, whether the materials are consolidated or unconsolidated; (3)

expected water-level fluctuations; (4) expected direction of the vertical head gradient--downward, upward, or fairly uniform with depth; (5) whether the aquifer is confined or unconfined;

and (6) the design of the monitoring well(s) (figs. 4-6). Completion requirements and practices

can differ considerably among wells (W. Lapham, U.S. Geological Survey, written commun.,

1995--see footnote 1).

 In most cases, wells installed for NAWQA Land-Use or Flowpath Studies will consist of

flush-threaded PVC pipe with short (2- to 10-ft) well screens (table 3). Installation of a filter

pack around the well screen and sealing of the annular space between the well casing and the

borehole wall also will be necessary for those installations in which the annular space could remain open after well installation. Each major element of well completion has specific design

objectives, which are discussed briefly here. A more detailed discussion of the major elements

of well completion has been written (W. Lapham, U.S. Geological Survey, written commun.,

1995--see footnote 1), and additional information related to completion procedures is given in

ASTM (1992) and Driscoll (1986).

The well casing and/or screen is installed in the borehole as the first step in well completion. After installation of the well casing and, if needed, the well screen, the major elements of

well completion consist of the following:

1. If a well screen is used and a filter pack is required, the primary filter pack is installed

around the well screen.

2. A secondary filter pack is installed above the primary filter pack.

3. Annular seals are installed to about frost level.

4. A surface seal is installed.

5. A protective casing is installed around the well at land surface.

An example of these major elements of well completion, in this case for a shallow well with

a filter-packed well screen installed in unconsolidated materials, is provided in figure 4. This is

a typical design for wells for Land-Use and Flowpath Studies.
37

Primary filter pack

The primary filter pack (also commonly called a sand or gravel pack) is material that fills

the annulus around and just above the well screen to retain and stabilize material from the

adjacent screened unit (fig. 4). A filter pack has a greater grain size than that of the aquifer

material in the vicinity of the screen. Filter-pack grain size and gradation are designed to stabilize the hydrologic unit adjacent to the screen and permit only the finest grains to enter the

screen during development, resulting in relatively sediment-free water for sampling after

development. The primary filter pack should consist of relatively inert material such as quartz,

contain no limestone or other calcareous materials such as shell fragments, and contain no

organic material such as wood fragments or lignite. Alternatively, filter-pack material of

known chemistry (ASTM, 1992) can be used, such as glass beads.

The primary filter pack commonly is extended up the annulus to a minimum of 5 ft above

the top of the screen (Hardy and others, 1989), if a secondary filter pack is impractical. The

primary filter pack must not intersect multiple water-bearing units, nor cross confining units

that otherwise would not be screened (table 3). Intersection of such units can result in an artificial, vertical, hydraulic connection along the annulus between these units, and can affect the

chemistry of the ground water being sampled.

Secondary filter pack

The secondary filter pack (fig. 4) is a finer grained material than the primary filter pack,

placed in the annulus between the primary filter pack and the overlying annular seal, or between different types of annular seals (ASTM, 1992, p. 124). The purpose of the secondary

filter pack is to prevent material used for the annular seal from infiltrating and clogging the

filter pack and from affecting ambient water chemistry. The secondary filter pack should consist of inert material, consistent with that of the primary filter pack. A length of secondary filter

pack of about 1 to 2 ft is recommended (Hardy and others, 1989, p. 16; ASTM, 1992, p. 129,

figs. 2 and 3).

Annular seals

Annular seal(s) are installed from above the secondary filter pack or the extended primary filter pack to near land surface, in order to seal the annular space between the casing and

borehole wall (fig. 4). These seals prohibit vertical flow of water between aquifers and prevent

cross-contamination of aquifers by contaminants. They also protect against infiltration of

water and contaminants from the surface.

A 3- to 5-ft plug should be placed above the extended primary or secondary filter pack

(ASTM, 1992). The plug is formed from a hydrated material such as bentonite or cement that

acts as a sealant. The choice of a sealant material must minimize possible effects on the constituents to be analyzed from the well (table 10). Penetration of the sealant into the underlying

filter pack should be limited to less than a few inches (Hardy and others, 1989).
38

Table 10. Characteristics of bentonite and cement as annular seals

[Information from ASTM (1992), Aller and others (1989), Hardy and others (1989), Driscoll (1986),

Gillham and others (1983), and Claassen (1982)]

BENTONITE

(A hydrous aluminum silicate composed primarily of montmorillonite)

Advantages:

- Readily available and inexpensive.

- Pellets and granules are easy to use.

- Remains plastic and will not crack if it remains saturated.

- Expands from 10 to 15 times dry volume when hydrated.

- Low hydraulic conductivity (about 1 x 10-7 to 1 x 10-9 centimeters per second)

Disadvantages:

- Effectiveness of seal difficult to assess.

- Complete bond to casing not assured.

- Because of rapid hydration, bentonite can stick to walls of annulus and bridge annulus.

- May not be an effective seal in unsaturated zone because of desiccation.

- Can affect the chemistry of the surrounding ground water by cation exchange of Na, Al,

K, Mg, Ca, Fe, and Mn from the bentonite with other cations in the ground water.

- Sets up with a pH between 8.5 and 10.5, which can affect the chemistry of the

surrounding ground water.

- Most bentonites contain about 4-6 percent organic matter, which might affect the

concentration of some organic constituents in ground water.

CEMENT

(Composed of calcium carbonate, alumina, silica, magnesia, ferric oxide, and sulfur trioxide

with pH ranges from 10 to 12)

Advantages:

- Readily available and inexpensive.

- Can assess continuity of placement using temperature or acoustic-bond logs.

Disadvantages:

- Requires mixer, pump, and tremie pipe for placement.

- Generally more cleanup required than with bentonite.

- Contamination can be introduced to borehole by the pump.

- Failure of the grout to form a seal can occur because of premature and/or partial setting

of the cement, insufficient grout column length, voids and/or gaps in the grout

column, or excessive shrinkage of the cement.

- Pure cement will shrink during the curing process, resulting in a poor seal between the

cement and both the casing and the borehole wall.

- Additives to the cement to compensate for natural shrinkage can cause an increase in

pH, dissolved solids, and temperature of the ground water during the curing

process. The increased pH causes precipitation of calcium and bicarbonate ions

from the ground water.

- Soluble salts in the cement can be leached by the ground water, thereby increasing the

concentrations of calcium and bicarbonate in the ground water.

- Cement may cause unusually high values of pH in ground-water-quality samples.

- Heat of hydration during curing can deform or melt thermoplastic casing such as PVC.
39

The remaining upper part of the annulus is grouted to below the frost line. The grout prevents movement of ground water and surface water within the annular space between the well

casing and borehole wall. It also maintains the structural integrity and alignment of the well

casing.

Drill cuttings removed from the borehole sometimes are used as grout instead of bentonite or cement, but the effectiveness of these materials as a sealant needs careful evaluation

and is not to be used for NAWQA wells. For NAWQA, bentonite, cement, or mixtures of bentonite and cement probably are the most common grout materials that will be used. Generally

bentonite is recommended for grout if the well is used for water-quality sampling. However,

as in the case of the underlying seal, the choice of a material depends on the purpose of the

well. Detailed discussions of characteristics of annular seals and methods of placement can be

found in ASTM (1992) and Driscoll (1986).

Surface Seal

The surface seal prevents surface runoff down the annulus of the well and, in situations

in which a protective casing around the well is needed, holds the protective casing in place.

The depth of installation of a surface seal can range from several feet to several tens of feet

below land surface. Local regulatory agencies might specify a minimum depth of installation.

Because of likely desiccation of bentonite, a cement surface seal is recommended.

Protective Casing

A protective casing should be installed around the well to prevent unauthorized access to

the well and to protect the well from damage. The protective casing is installed at the same

time as the surface seal and should extend to below the frost line (ASTM, 1992). One design

for protective casing is a steel casing with vented locking protective cover and weep hole,

which permits condensation to drain out of the annular space between the protective casing and

well casings (fig. 4). ASTM (1992, p. 132) also calls for coarse sand or pea gravel or both to

be placed in the annular space between the protective casing and the well to prevent entry of

insects. A second design is a steel casing with bolted or locked manhole cover enclosing a well

that is flush with the land surface.

Well Development

Wells drilled for the NAWQA Program should be developed to enhance flow of water to

the well, to remove sediments that are artifacts of well installation, and to provide water representative of the unit being sampled. Developing a well mitigates artifacts associated with

drilling, such as changes in aquifer permeability, sediment distribution, and ground-water

chemistry. Redevelopment of a well can be necessary because of sedimentation in the well

casing, or clogging of the aquifer or well screen.

Development of a well is to be documented as discussed in the section “Documentation.”

Documentation includes: (1) the method of development; (2) equipment being used; (3) the

volume of water removed; (4) a measure of the clarity of water removed from the well over
40

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 sampling. Estimates of the recovery rate and recovery time of the water level in the well after pumping 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 characteristics, 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 primary 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 groundwater 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 welldevelopment 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, documentation of network-design information for each Study-Unit Survey, Land-Use Study, and

Flowpath Study is required. Types of network-design information include network identification, 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 information 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 Memorandum No. 93-03, written commun., 1993).
41

WELL-INFORMATION CHECK LIST

 NAWQA Study Unit: ____________________ Study component: __________________

Site ID: ________________________ Station name: ______________________

 Well type (for example, public water supply, domestic water supply, observation, monitoring):

____________________________________________________________________________

Item in site file Date item filed

Criteria for well selection ___________

GWSI data entered into National Water Information System ___________

Paper copy of GWSI form ___________

Copies of permission to complete activity (for example, drilling or

sampling)_____________________________________________ ___________

List permits___________________________________________ ___________

Copies of field notes and logs:

Driller's log ___________

Lithologic log ___________

 Cuttings ___________

 Cores ___________

Well-construction record ___________

Well-development record ___________

Checks on well-construction integrity ___________

Other ____________________________________________ ___________

Well-location information:

Well-location map(s) ___________

Site-sketch map ___________

Written description of location ___________

Well-casing elevation (elevation, and method and date of

determination) ___________

Photographs of well and vicinity, with measuring/sampling

point identified ___________

Land use-land cover form (enter dates of updates): ___________

___________

___________

___________

___________

___________

Figure 7. Example of a well-information check list for the National Water-Quality Assessment

Program.
42

Item in site file Date item filed

Water-quality records for each sampling event (for example,

purging, field measurements, field forms) ___________

___________

___________

___________

___________

Water-level measurements: ___________

___________

___________

___________

___________

Other information (for example, historical water-level records, type

of pump in well, location of sampling point, sampling history):

__________________________________________________ ___________

__________________________________________________ ___________

__________________________________________________ ___________

__________________________________________________ ___________

__________________________________________________ ___________

Remarks:

Figure 7. Example of a well-information check list for the National Water-Quality Assessment

Program--Continued.
43

In NWIS-I, water-quality-related data are stored in two data bases: GWSI (GroundWater Site Inventory), where, for example, well-location and well-construction information

are stored; and QWDATA (Quality of Water data), where results of water-quality analyses are

stored. Specific minimum information (table 11) is required for creation of a site file and for

storage of data in these data bases. Specific minimum information also is required to be recorded on the USGS NWQL (National Water Quality Laboratory) ASR (Analytical Services

Request) form for acceptance of a sample for laboratory analysis by the NWQL. Replacement

of NWIS-I by NWIS-II might change some of the data-entry requirements currently mandated.

In addition to specific minimum information required for creation of a site file and for storage

of data in the GWSI and QWDATA data bases, other site and well-related information should

be collected to the extent possible by NAWQA Study Units.

Documentation of the methods and materials used for well installation is required for

each new well installed and for each existing well selected to the extent that the information is

available (fig. 8). Documentation of newly installed wells is to be completed at the time of or

directly after well completion and development. Documentation includes lithologic, driller's,

and well-construction logs (U.S. Geological Survey, 1980, p. 2-80 to 2-81); and a record of

well development (fig. 9). A record should be kept of other logs collected during and after

drilling, such as drilling-rate and fluid-loss logs (U.S. Geological Survey, 1980, p. 2-80), borehole-geophysical logs, and field and laboratory analyses of aquifer materials and water samples, results of tests to determine construction integrity of the well, water-level measurements,

and aquifer tests.

Also in the well file are location map(s) and site sketches (see for example fig. 10). The

location map(s) and site sketch need to be of sufficient detail and scale to enable field location

of a well by field personnel unfamiliar with the site. Information on the location map(s) typically includes roads, topography, water bodies, and cultural features. Compass directions or

latitude/longitude and a horizontal scale need to be indicated on the location map(s). Distances

from milepost markers or other permanent cultural features to the well site also are useful information. The site sketch identifies the well location in relation to nearby features such as

roads, railroad lines, fences, houses, barns, and out buildings. Compass directions need to be

indicated on the sketch, and distances between features and the well typically are included on

the sketch. A sketch of the well head identifies features of the well such as the height of the

top of the casing in relation to land surface, the locations of measuring and sampling points,

and general characteristics of the protective casing. Written descriptions of the site and well

characteristics compliment the site and well-head sketches with other useful information, such

as site access, whether or not the well is locked, whether or not owner notification is required

prior to sampling, tools required, difficulties that might be encountered in locating the well,

measuring the water level, or sampling the well, and the possible presence of animals.

Well records must identify the location of the well and describe the point from which

water level is measured (the “measuring point”). The locations and altitudes of wells sampled

as part of Study-Unit Surveys and most Land-Use Studies will be determined from Geological

Survey 7 1/2-minute quadrangle maps. For some Land-Use Studies and for Flowpath Studies,

greater accuracy in locations and altitudes of wells will be required than can be determined
44

from 7 1/2-minute quadrangle maps. In these cases, standard second-order ground-surveying

techniques (Davis and others, 1966) generally are to be used. An alternative to ground surveying

is to use a global-positioning system. In addition, the records should show if a vertical reference

point has been established near the well that can be used to check the measuring point and to reestablish a measuring point that has been changed or destroyed.

Table 11. Information required for creation of files and storage of water-quality-related data in

U.S. Geological Survey data bases within the National Water Information System-I

Data required for creation of a site file in the Ground-Water Site Inventory data base1 (GWSI)

Data description

Component number for

data entry into GWSI

Example code

(Description of code)

Agency Code

Site (Station) Identification

(Latitude/longitude/sequence no.)

Station Name

Latitude

Longitude

Station locator sequence

 number

District/User

State

County Code

Agency Use

Station Type

Data Reliability

Site Type

Use of site

C4

C1

C12

C9

C10

C815

C6

C7

C8

C803

C802

C3

C2

C23

USGS

394224075340501

Alpha

394224

753405

01

24 (Maryland)

10 (Delaware)

003 (Sussex)

A (Active)

Y (Well)

C (Field Checked)

W (Well)

O (Observation)

Data required for storage of sample analyses in the Water-Quality data base (QWDATA)

Data description

 Example code

 (Description of code)

Agency Code

Station Identification

Sample Medium

Sample Type

Hydrologic (“Hydro”) Event

Hydrologic (“Hydro”) Condition

Begin Date and Time (month/day/year,

 standard military time)

Analysis Status

Analysis Source

USGS

394224075340501

6 (ground water)

2 (blank sample)

9 (routine sample)

9 (stable, normal stage)

090988, 1530 hrs

H (initial entry)

9 (USGS laboratory and field)

 1From Ground-Water Site Schedule Form No. 9-1904-A, February, 1987.
45

RECORD OF WELL DRILLING, CONSTRUCTION, AND COMPLETION

SITE ID________________________ STATION NAME______________________________ OTHER ID_____________________________

7.5’ QUAD_____________________________________ COUNTY STATE

OWNER DRILLER

WELL DRILLING

 START DRILLING: DATE ___ / ___ / ___ TIME ___ : ___ EST

 COMPLETE DRILLING: DATE ___ / ___ / ___ TIME ___ : ___ EST

EQUIPMENT/MATERIALS DECONTAMINATION PROCEDURES:

 DETERGENT WASH __________________; STEAM CLEANED __________________; OTHER ______________

DRILLING METHOD:

 ______ AUGER (TYPE: ____________________________); ROTARY (TYPE:______________________)

 ______ PERCUSSION (TYPE:______________________________); ____ OTHER ________________

BOREHOLE DATA:

BOREHOLE DIAMETER: ________ inches; TOTAL DEPTH OF BOREHOLE: ________ feet;

APPROXIMATE DEPTH TO THE WATER TABLE: ________ feet

Figure 8. Examples of forms used to record well-drilling, -construction, and -completion information,

and to diagram well construction.

MATERIAL DESCRIPTION FROM TO THICKNESS

SAND, SILT, CLAY ETC SORTING COLOR WET/DRY feet feet feet
46

WELL CONSTRUCTION

 START WELL CONSTRUCTION: DATE ___ / ___ / ___ TIME ___ : ___ EST

 COMPLETE WELL CONSTRUCTION: DATE ___ / ___ / ___ TIME ___ : ___ EST

WELL COMPLETION

 START WELL COMPLETION: DATE ___ / ___ / ___ TIME ___ : ___ EST

 COMPLETE WELL COMPLETION: DATE ___ / ___ / ___ TIME ___ : ___ EST

COMMENTS_________________________________________________________________________

_____________________________________________________________________________________

Figure 8. Examples of forms used to record well-drilling, -construction, and -completion information,

and to diagram well construction--Continued.

CASING/SCREEN

 MATERIAL

CASING

THICKNESS,

SCREEN TYPE,

SLOT SIZE, ETC.

DIAMETER FROM TO TOTAL

LENGTH

inches feet feet feet

CASING:

-

SCREEN:

COMPLETION ELEMENT

COMPLETION MATERIALS AMOUNT FROM TO TOTAL

LENGTH

lbs; lbs/gal; etc. feet feet feet

PRIMARY FILTER PACK

-

SECONDARY FILTER PACK

ANNULAR SEALS

SURFACE SEAL

WELL PROTECTOR
47

WELL-CONSTRUCTION DIAGRAM

SITE ID STATION NAME

OTHER ID

7.5’ QUAD COUNTY STATE

OWNER DRILLER

 Notes

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

__________________________________________

Backfill Type

Figure 8. Examples of forms used to record well-drilling, -construction, and -completion information,

and to diagram well construction--Continued.
48

RECORD OF WELL DEVELOPMENT

Date: __________________ By: ___________________

SITE ID STATION NAME _ OTHER ID ________

7.5’ QUAD______________________________________ COUNTY ___________ STATE

OWNER DRILLER

WELL CONSTRUCTION

TOTAL DEPTH OF WELL _____________ _______ _ WELL DIAMETER ___________________ _ _

DEPTH(S) TO SCREENED OR OPEN INTERVAL(S) _________________________ _____________ _

WATER LEVEL

MEASUREMENT POINT (MP) DESCRIPTION

MEASURING POINT _______________ feet ABOVE ____ BELOW _____ LSD (Land surface datum)

Figure 9. Example of a form to summarize development of a well.

DATE TIME PERSONNEL

TYPE - post drilling,

pre-development,

post-development,....

HOLD CUT H2O DEPTH

BELOW MP MP H2O DEPTHBELOW LSD

feet feet feet feet above

LSD feet

ESTIMATION OF PURGE VOLUME AND PURGE TIME FOR WATER-QUALITY SAMPLING

Well volume = V = 0.0408 HD2 = ___ gallons

V= volume of water in the well, in gallons

D = inside diameter of well, in inches

H = height of water column, in feet

Well casing

 diameter (D)

1.0

1.5

2.0

3.0

4.0

4.5

5.0

Gallons/foot

 of casing

0.04

0.09

0.16

0.37

0.65

0.83

1.02

Well casing

 diameter (D)

6.0

8.0

10.0

12.0

24.0

36.0

Gallons/foot

 of casing

1.47

2.61

4.08

5.88

23.5

52.9

Purge volume = (n)(V) = ______ gallons

n = number of well volumes to be removed during purging

Q = Estimated pumping rate = ___ gallons per minute

Approximate Purge Time = (Purge Volume)/Q = ______ minutes
49

RECORD OF WELL DEVELOPMENT--Continued

Date: __________________ By: _________________________

SITE ID STATION NAME _______ OTHER ID

WELL DEVELOPMENT

METHOD(S): BAILING____; MECHANICAL SURGING ____; INDIRECT EDUCTION ____ ;

PUMPING/OVERPUMPING, AND BACKWASHING____ ; BACKWASHING____ ;

JETTING WITH WATER ____; JETTING WITH AIR____; OTHER_________________________________________

PUMP DESCRIPTION___________________________________________________________________________________

REMARKS:____________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

Figure 9. Example of a form to summarize development of a well--Continued.

TIME TEMPERATURE

CONDUC

TIVITY pH DISSOLVEDOXYGEN TURBIDITY

APPROX.

PUMPING

 RATE

COMMENTS

(INCLUDING CLARITY OF

WATER AND SUCCESS

OF DEVELOPMENT, ) HR:MIN o

C
50

Figure 10. Examples of well-location and site-sketch maps and information related to site

conditions and restrictions.

KEBe61

Base map from U.S. Geological Survey 1:24,000 Galena, Md., quadrangle

39o17’30”

39o20’

Location map(s):

75o 75 55’ o57’30”
51

Figure 10. Examples of well-location and site-sketch maps and information related to site

conditions and restrictions--Continued.

Well KEBe61 (lat: 391803, long: 755552) is located in the Galena 7.5 min quadrangle

about 2 miles south of Locust Grove, MD on Locust Grove/Centerville Rd (RT 444). The

well is the most southern of the 3-well cluster on the west side of Locust Grove Rd., just

south of telephone pole REA/20/25. This USGS well was installed on 5/5/85, is constructed of 2-inch diameter PVC, is 50.5 ft deep, and has a steel protective casing with a

USGS lock. Contact property owner at ( )___-____ the day before sampling.

Example well-location description and information:

Example site sketch:
52

Photographs of each well sampled and features in the vicinity of those wells are required.

The purpose of the chronological series of documentary photographs of each well site is to provide a visual record of land use near the well, which can aid in the explanation and interpretation

of analytical results, and can aid in locating the well in the future. When changes occur at or near

the well that might affect hydrologic interpretation of data from the well, a new set of photographs is required to document those changes. For example, changes in the reference datum of

the well or changes in land use near the well might warrant a new set of photographs. A new set

of photographs also would be appropriate if they will aid in locating the well in the future. The

set of photographs are (1) one photograph of the well and surrounding area as seen when

approaching the well; (2) one close-up photograph of the well and water-level measuring point;

(3) four photographs that show the area near the well--one each to the north, east, south, and

west; and (4) any additional photographs to document features that might influence the chemistry

of water collected from the well. General information and the identification of important features shown on the photographs need to be recorded. The minimum general information includes

the date of the photographs, and location and identification of the well (site identification number

or station name, latitude and longitude, written description). Features identified on the photographs will include at least the measuring point used for water-level measurements and the sampling point used for water-supply wells.

A field sheet (fig. 11) that documents land use and land cover and other site characteristics

in the vicinity of each well is to be completed in its entirety the first time a well is sampled. This

information must be rechecked each time a well is sampled and, if any changes have occurred,

the changes must be noted on a new sheet. This information is especially important documentation for wells sampled in Land-Use and Flowpath Studies, but also may help explain waterquality results from wells sampled for the Study-Unit Survey, particularly if those wells are resampled at a later time. The land-use and land-cover field sheet filled out by 1991 Study-Unit

staff (fig. 11) was modified slightly from the form used in the pilot NAWQA Program (Hardy

and others, 1989; Scott, 1989) based on experience with its use during that program. The form

in figure 11 currently is being evaluated for use by the 1994 Study Units.
53

LAND-USE/LAND-COVER FIELD SHEET - GROUND-WATER COMPONENT OF NAWQA STUDIES - Page 1 (04/93)

1. NAWQA Study-Unit name using 4-letter abbreviation: ____________

Field-check date ___/___/___ Person conducting field inspection:_________________________________

Well station-id: ___________________ Latitude:__________________ Longitude:_______________________

2. LAND USE AND LAND COVER CLASSIFICATION - (modified from Anderson and others, 1976, p.8). Check all

land uses that occur within each approximate distance range from the sampled well. Identify the predominant land

use within each distance range and estimate its percentage of the total area within a 1/4-mile radius of the well.

3. AGRICULTURAL PRACTICES within 1/4 mile of the sampled well.

a. Extent of irrigation - Indicate those that apply.

Nonirrigated ____ Supplemental irrigation in dry years only ____, Irrigated ____

b. Method of irrigation - Indicate those that apply.

Spray ___ Flood ___ Furrow ___ Drip ___ Chemigation ___ Other ___ (Specify) ____________

c. Source of irrigation water - Indicate those that apply.

Ground water ____ Surface water ____ Spring __ __

Sewage effluent ____ (treatment): Primary ____ Secondary ____ Tertiary ____

d. Pesticide and fertilizer application - Provide information about present and past pesticides and fertilizers

used, application rates, and application methods._______________________________________________

_____________________________________________________________________________________

e. Crop and animal types - Provide information about present and past crop and animal types, and crop rotation

practices._____________________________________________________________________________

_____________________________________________________________________________________

 Entered by____________________ Date ___/___/___ Checked by __________________ Date ___/___/___

Figure 11. Land-use and land-cover field sheet for the 1991 Study Units, National Water-Quality

Assessment Program.

Land use and land cover

Within

100 ft

100 ft1/4 mi Comments

 I. URBAN LAND

--Residential

--Commercial

--Industrial

--Other (Specify)________

 II. AGRICULTURAL LAND

--Nonirrigated cropland

--Irrigated cropland

--Pasture

--Orchard, grove, vineyard,

 or nursery

--Confined feeding

--Other (Specify)________

 III. RANGELAND

 IV. FOREST LAND

 V. WATER

 VI. WETLAND

VII. BARREN LAND

Predominant land use

Approximate percentage of area

covered by predominant land use
54

LAND-USE/LAND-COVER FIELD SHEET - GROUND-WATER COMPONENT OF NAWQA STUDIES-Page 2 (04/93)

Well station-id: ______________________________ Field-check date: ___/___/___

4. LOCAL FEATURES - Indicate all local features that may affect ground-water quality which occur within each

approximate distance range from the sampled well.

Figure 11. Land-use and land-cover field sheet for the 1991 Study Units, National Water-Quality

Assessment Program--Continued.

Feature within

100 ft

100 ft -

1/4 mi

Comments

Gas station

Dry cleaner

Chemical plant or

storage facility

Airport

Military base

Road

Pipeline or fuel

storage facility

Septic field

Waste disposal pond

Landfill

Golf course

Stream, river, or creek

Perennial __

Ephemeral __

Irrigation canal

Lined __ Unlined __

Drainage ditch

Lined __ Unlined __

Lake

Natural __ Manmade __

Reservoir

Lined __ Unlined __

Bay or estuary

Spring

 Geothermal (> 25 C)__

 Nongeothermal__

Salt flat or playa

Dry __ Wet __

Mine, quarry, or pit

Active __Abandoned__

Oil well

Major withdrawal well

Waste injection well

Recharge injection well

Other ______________
55

LAND-USE/LAND-COVER FIELD SHEET - GROUND-WATER COMPONENT OF NAWQA STUDIES -Page 3 (04/93)

Well station-id: ______________________________ Field-check date: ___/___/___

5. LAND-USE CHANGES - Have there been major changes in the last 10 years in land use within 1/4 mile of

the sampled well? Yes __, Probably __, Probably not __, No __ If yes, describe major changes.

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

6. ADDITIONAL COMMENTS - Emphasize factors that might influence local ground-water quality.

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

____________________________________________________________________________________

Remarks

Figure 11. Land-use and land-cover field sheet for the 1991 Study Units, National Water-Quality

Assessment Program--Continued
56

Measurement of Water Levels and Collection of Additional Hydrogeologic

and Geologic Data

Collecting water levels and additional hydrogeologic and geologic data at wells is crucial

to characterization of the ground-water system and for interpretation of ground-water quality in

all three NAWQA ground-water study components. In-depth description of the methods to collect these data is beyond the scope of this report. Nevertheless, the importance of collecting these

data for NAWQA studies must be emphasized. The user is referred to the references cited for the

additional information needed.

The degree of detail of hydrogeologic and geologic characterization needed differs among

the three study components. In general, conducting a Study-Unit Survey first requires identifying

all the aquifers in a Study Unit, selecting aquifers for study, characterizing the ground-water system of the aquifers selected for study, and selecting and sampling wells in those aquifers. LandUse Study areas are selected, in part, to reflect distinct hydrogeologic and land-use settings within Study-Unit Survey subunits. A primary objective of Flowpath Studies is to characterize

ground-water quality in relation to ground-water flow. Each study component generally will

gather enough information to determine: the geometry, boundary conditions, lithologic and hydraulic properties of aquifers and confining units; the rates and directions of ground-water flow;

and the general mineralogy of the aquifers investigated.

Water-level measurements are required each time before a well is sampled, unless the well

construction makes measurement impossible. Acquisition of additional hydrogeologic and geologic data from aquifer tests, sampling of geologic materials, and geophysical surveys, including

borehole geophysical logging, is recommended and may be required for certain Land-Use and

Flowpath Studies.

Water Levels

Water levels in wells are measured in all NAWQA ground-water studies to help determine

hydraulic gradients and rates and directions of ground-water flow and to aid interpretation of

ground-water-quality data. For Flowpath Studies, a local-scale water-table map is necessary for

determining the location and trend of the transect or flowpath selected. Water levels also help

determine locations of ground-water recharge and discharge, the amount of water in storage in

an aquifer, the change in storage over time, and aquifer hydraulic characteristics. Repeated measurements of water levels over time provide a chronology of water-level fluctuations that can aid

interpretation of water-quality data.

A water level is measured and recorded prior to purging the well from which samples will

be collected. The form in figure 12, or a similar form such as Form 9-1904-E (revised September

1980), can be used to record these water-level measurements. For wells that allow direct access

for making downhole water-level measurements, discrete water levels commonly are measured

with a steel or electric tape and continuous measurements are made using a digital recorder or

pressure transducer. In supply wells, water levels commonly must be measured indirectly using

an air line. Standard USGS practice (U.S. Geological Survey, 1980, p. 2-8) for measuring a static

water level in a well is to make two consecutive measurements to an accuracy of 0.01 ft. If the

two measurements do not agree within a precision of about 0.02 ft., measurements are repeated

until the reason for the lack of agreement is determined or until the results are shown to be reliable.
U.S. DEPT. OF INTERIOR WELL NO.___________________

GEOLOGICAL SURVEY MP HEIGHT _________________

WATER RESOURCES DIVISION

WATER-LEVEL DATA

DATE WATER LEVEL (BELOW LSD) STATUS METHOD HOLD CUT DEPTH BELOW MP REMARKS DATES PUNCHED/ ENTERED

235 # * 237= * 238= * 239= *

235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *235 # * 237= * 238= * 239= *

Site Ident. No.

5 19

R = 234 *

•

T = A *

••••••••••••••

Method ofMeasurement

Site Status

239 = A C E G H L M R S T Z

airline, calibrated, estimated, pressure, calibrated, geophysical, manometer, reported, steel, electric, other

airline gage pressure gage logs tape tape

238 = D F G H O P R S T Z

 dry, flowing, nearby, nearby, obstruction, pumping, recently, nearby, nearby, other

 flowing recently pumped pumping recently

flowing

MEASURING POINT

R = 320 T = A D M *

add, delete, modify

*

M.P. Begin DateM.P. End DateM.P. HeightM.P. Remark

321 #322 =323 =324 =

**

*

*

•

Figure 12. Example of a form to record water-level data in a well.

57
58

Traditionally, lead weights have been used on tapes and electric sounders in order to keep

the tape taut and plumb. Concern regarding the loss of a lead weight in a well and the possible

effects of lead dissolution on water quality with respect to US Environmental Protection Agency contamination standards has resulted in a USGS policy that prohibits the use of lead weights

in wells. In selecting an alternative weight, the bias introduced to concentrations of constituents measured in the water sample if the weight is lost in the well, along with potential breach

of health standards also must be considered. The currently recommended material for weights

is stainless steel.

In general, water levels in wells sampled by NAWQA will be measured using a chalked,

steel tape. However, selection of a method for measuring a water level depends on accessibility, depth to water, frequency of measurements, and the intended use of the data. For wells in

which direct measurement of water level is not possible, a pressure or head gage could be considered as an alternative method. In smaller scale studies, such as a Flowpath Study, specialized

equipment and methods might be considered. For example, electrical pressure-sensitive transducers linked to a data logger can be used to record water levels over time in wells along a flowpath or in selected Land-Use Study wells. Transducers require periodic calibration. Several

methods of measuring water levels in wells are discussed in Hollett and others (1994), Latkovich, (1993), Driscoll (1986), Ritchey (1986), U.S. Geological Survey (1980), Garber and Koopman (1968), Mogg (1977), and Sanders (1984).

A measuring point must be established at each well to ensure comparability of water-level

measurements taken in the same well and between wells in each study component. The measuring point is established in reference to land-surface datum. It is selected as the most convenient place from which to measure water level, and must be clearly and permanently marked.

If a point at the top edge of the casing is selected as the measuring point, the casing should be

notched, if possible, to produce a permanent reference mark.

It is recommended that a vertical reference point also be established near each well. This

reference point is an arbitrary vertical datum established to periodically check the measuring

point and to re-establish a measuring point that has been changed or destroyed.

Additional Hydrogeologic and Geologic Data

Collection of hydrogeologic and geologic data are especially critical for the Land-Use

and Flowpath Studies, for which it is necessary that the geologic framework and hydrology of

the area be well defined (Gilliom and others, 1995). Generally, conducting Land-Use or Flowpath Studies will require installing wells at predetermined sites. This installation process provides Study Units with the opportunity to collect samples of geologic materials during drilling,

run borehole-geophysical logs, and conduct aquifer or slug tests after installation.

Hydrogeologic and geologic data also can aid in selection of additional well-installation

sites and in design of wells installed for the Land-Use or Flowpath Studies. For example, in

Land-Use Studies, selected borehole-geophysical logs could provide a preliminary indication

of water-quality variation with depth, and thereby provide a preliminary areal assessment of
59

the distribution of water-quality constituents in recently recharged ground water. These data

also can aid in identifying and mapping local hydrogeologic conditions, including areal extent,

thickness, and lithologic and hydraulic properties of hydrogeologic units.

Aquifer tests

Analyses of data from aquifer tests provide estimates of hydraulic properties of the aquifers being investigated (Lohman, 1972; U.S. Geological Survey, 1980, p. 2-115 to 2-149). The

Study Unit should compile and analyze aquifer-test data that may be already available for

water-supply wells in the subunits of interest. In addition, the Study Unit should plan to conduct some type of aquifer tests for the Flowpath Studies if hydraulic data are not available or

inadequate. Large-scale, long-term aquifer tests may not be practical for NAWQA studies.

However, small-scale, short-term aquifer tests, such as slug tests, can be run to estimate

hydraulic conductivity and storage of the aquifer in the immediate vicinities of the screened

intervals of Land-Use and Flowpath Study wells. Estimates of hydraulic conductivity and

transmissivity also can be determined from the ratio of well discharge to drawdown (specific

capacity). Such data are needed for computer modeling of the aquifer system. Preliminary

two-dimensional ground-water cross-sectional modeling that reflects a typical range of geometries for the shallow flow system at possible flowpath sites is recommended as a valuable aid

in designing the spacing and screen depth of flowpath wells.

Geologic materials

Samples of geologic materials are collected as cores or cuttings. Cores are obtained in

situ using downhole samplers and are relatively undisturbed representations of the subsurface

materials. Cuttings generally are transported through the well bore and are disturbed samples.

Methods of collection of cores and cuttings range widely in complexity. The quality and intended use of data determine the method of sample collection (table 12). Frequently, there is

inadequate recognition that the sampling method must be compatible with the intended use of

the sample (Shuter and Teasdale, 1989, p. 80). Guidance on proper field techniques for sample

collection are provided in Acker (1974), ASTM (1983, 1984), Aller and others (1989), and

Shuter and Teasdale (1989).

Samples of geologic material can provide data on lithology, stratigraphy, mineralogy,

chemistry, structure, grain-size distribution, dry and wet-bulk density, moisture content, porosity, and permeability to aid interpretation of ground-water quality. The mineralogical and

chemical composition of the aquifer can provide data critical to rock-water interactions in an

aquifer; the mobilization of naturally occurring elements into ground water; the geochemical

evolution of ground water along flowpath; zones of contamination; the exchange or partitioning of a substance between solid and liquid phases; and possible sources of contamination, evolutionary reaction paths, and adsorption or desorption of a contaminant moving with the water

phase. Selected references that describe such studies have been compiled (W. Lapham, U.S.

Geological Survey, written commun., 1995--see footnote 1). Pore water also can be extracted

from core samples for analysis of its chemical composition (Patterson and others, 1978; Munch

and Killey, 1985).
60

Table 12. Summary matrix of relative quality of aquifer property measured or estimated using different

sample-collection methods1

[E=Excellent; G= Good; F=Fair; P= Poor; NA= Not Applicable]

1The relations given in this table generally apply; there are exceptions depending on specific techniques employed during drilling or coring. For example, return of cuttings in drilling fluid during rotary drilling can yield information relating samples to depth

that varies considerably depending on specific drilling techniques used.

2From laboratory permeameter tests. Indirect estimates of hydraulic properties can be made from the properties of cuttings from

a borehole.

Method of sample collection

Cores obtained from Cuttings

Property Measured

Physical properties

 --Dry & wet-bulk density E E E E G NA NA NA NA NA

 --Moisture content E E E E G NA NA NA NA NA

 --Porosity E E E E G NA NA NA NA NA

 --Grain-size distribution E E E E E G G F P P

Geologic properties

 --Lithology E E E E G G G F P P

 --Mineralogy E E E E G G G F P P

 --Chemical composition E E E E G G G F P P

 --Stratigraphy E E E E G NA NA NA NA NA

 --Structure E E E E G NA NA NA NA NA

 --Fracture location in

 cohesive, unconsolidated

 material, such as till

G G G G G NA NA NA NA NA

 --Fracture characteristics in

 cohesive, unconsolidated

 material, such as till F F F F F NA NA NA NA NA

 --Fracture location in rock G NA NA NA NA NA NA NA NA NA

 --Fracture characteristics in

 rock

F NA NA NA NA NA NA NA NA NA

Hydraulic properties2

 --Specific yield E E E E F NA NA NA NA NA

 --Permeability G G G G F F F P P P

 --Hydraulic conductivity G G G G NA NA NA NA NA NA

Other

 --Identification of

 geohydrologic units

E E E E E G G F P or

NA

P or

NA

 --Sample from known depth E E E E E G G F P or

NA

G to

NA

 --Minimal disturbance to

 sample during collection E E to G E to G G G to F F F P P P Core drilling Thin-walled samplers (Shelby, Denison, etc.) Side-wall samplers Piston samplers Split-spoon samplers In air stream from air- rotary drilling with casing In drilling fluid from dual- well reverse circulation On auger flights or on drill bits As return from auger flights In drilling fluids in

uncased boreholes
61

Qualitative information about subsurface geology also is obtained during drilling by

observing and recording drilling-equipment response, drilling rate, borehole stability, and loss

or gain of drilling fluid (Driscoll, 1986; Shuter and Teasdale; 1989); and by applying conepenetration tests (Chiang and others, 1992; Smolley and Kappmeyer, 1991; and Robertson and

Campanella, 1986) and borehole-geophysical logs (Keys, 1990).

Borehole geophysics

The NAWQA Program recommends that geophysical data be obtained from NAWQA

wells to the extent possible. The drilling method selected may preclude use of some boreholegeophysical methods (table 13), as many borehole-geophysical logs must be run in uncased,

mud-filled boreholes.

Borehole-geophysical logs can provide information on borehole and well-casing characteristics, and on aquifer and confining-unit properties (Keys, 1990). Because the chemical constituents of water affect the responses of nearly all borehole-geophysical logs, these logs also

contain information that represents water chemistry (Jorgensen, D.G., 1990). Repetitive logging at a site can provide information on temporal variations of water chemistry. Several types

of logs often enable interpretation that would not be achieved from a single log.

Principles and instrumentation, calibration and standardization, quality control, and interpretation and application of most borehole-geophysical methods to ground-water investigations are described in detail in Keys (1990). References also are available that describe

considerations related to drilling methods in planning and performing borehole-geophysical

logging for ground-water studies (Hodges and Teasdale, 1991) and information on calibration

and standardization of geophysical well-logging equipment for hydrologic applications

(Hodges, 1988). A bibliography compiled by Taylor and Dey (1985) of borehole geophysics

as applied to ground water lists references by subject heading relevant to application of borehole-geophysical logging to ground-water hydrology.
Table 13. Summary matrix of potential applications of borehole-geophysical logs commonly used in ground-water investigations

[Modified from Keys, 1990, table 2]

Type of log

Varieties and

related techniques Properties measured Potential applications

Required hole

conditions Other limitations

Spontaneous

potential.

Electric potential

caused by salinitydifferences in borehole and interstitialfluids.

Lithology, shale content,

water quality.

Uncased hole filled

with conductivefluid.

Salinity difference

needed betweenborehole fluid andinterstitial fluidscorrect only forNaCl fluids.

Single-point

resistance.

Conventional,

differential.

Resistance of rock,

saturating fluid,and borehole fluid.

High-resolution lithology,

fracture location bydifferential probe.

Uncased hole filled

with conductivefluid.

Not quantitative; holediameter effects

significant.

Multielectrode. Normal, focused, or guard. Resistivity, in ohm- meters, of rock and

saturating fluids.

Quantitative data on

salinity of interstitialwater, lithology.

Uncased hole filled

with conductivefluid.

Normals provide incorrect

values and thicknessesin thin beds.

Gamma. Gamma spectral. Gamma radiation from

natural or artificialradioisotopes.

Lithology--may be

related to clay andsilt content and permeability; spectralidentifies radioisotopes.

Any hole conditions,

except very large,or several strings ofcasing and cement.

- -

Gammagamma. Compensated (dual detector). Electron density. Bulk density, porosity, moisture content,

lithology.

Optimum results in

uncased; qualitativethrough casing ordrill stem.

Severe hole-diameter

effects.

Neutron. Epithermal, thermal,

compensated activation,pulsed.

Hydrogen content. Saturated porosity,

moisture content,activation analysis,lithology.

Optimum results in

uncased; can be calibrated for casing.

Hole-diameter and

chemical effects.

Acoustic

velocity.

Compensated wave

form, cement bond.

Compressional wave

velocity.

Porosity, lithology,

fracture locationand character,cement bond.

Fluid-filled, uncased,

except cement bond.

Does not see secondary

porosity; cementbond and wave formrequire expert analysis.

62
Table 13. Summary matrix of potential applications of borehole-geophysical logs commonly used in ground-water investigations--Continued

Type of log

Varieties and

related techniques Properties measured Potential applications

Required hole

conditions Other limitations

Acoustic

televiewer.

Acoustic caliper. Acoustic reflectivity

of borehole wall.

Location, orientation,

and character offractures and solutionopenings, strike anddip of bedding,casing inspection.

Fluid-filled, 3-to16-inch diameter.

Heavy mud or mud

cake attenuate signal;very slow logging.

Caliper. Oriented, 4-arm highresolution bow spring. Hole or casing diameter. Hole-diameter correc- tions to other logs,

lithology, fractures,hole volume forcementing.

Any conditions. Significant resolution

difference betweentools.

Temperature. Differential. Temperature of fluid near sensor. Geothermal gradient, in-hole flow, location

of injection water,correction of otherlogs, curing cement.

Fluid-filled. Accuracy and resolution

of tools varies.

Conductivity. Resistivity. Most measure resistivity of fluid in hole. Quality of borehole fluid, in-hole flow,

location of contaminant plumes.

Fluid-filled. Accuracy varies,

requires temperaturecorrection.

Flow. Spinner, radioactive

tracer, brine tracer,thermal pulse.

In hole-flow, location

and apparenthydraulic conductivityof permeable interval.

Fluid-filled. Spinners require

higher velocities.Needs to becentralized.

Radar. Single-hole reflection,

crosshole tomography,borehole-to-surfacemeasurements.

Radar wave

reflection.

Rock structure. Dry or fluidfilled, uncased

or PVC-casedhole.

Metal affects

measurements.

Electromagnetic

induction.

Electromagnetic

conductivity.

Lithology,

water quality.

Fluid-filled, uncased

or PVC-cased hole.

Metal affects

measurements.

63
64

REFERENCES CITED

Acker, W.L., III, 1974, Basic procedures for soil sampling and core drilling: Scranton, Pa.,

Acker Drill Co., Inc., 246 p.

Aller, Linda, Bennett, T.W., Hackett, Glen, Petty, R.J., Lehr, J.H., Sedoris, Helen, Nielson,

D.M., and Denne, J.E., 1989, Handbook of suggested practices for the design and installation of ground-water monitoring wells: Dublin, Ohio, National Water Well Association,

398 p.

Alley, W.M., ed., 1993, Regional ground-water quality: Van Nostrand Reinhold, New York,

634 p.

Alley, W.M., and Cohen, P., 1991, A scientifically based nationwide assessment of groundwater

quality in the United States: Environmental Geology and Water Science, v. 17, no 1., p. 17-

22.

Anderson, J.R., Hardy, E.E., Roach, J.T., and Witmer, R.E., 1976, A land use and land cover

classification system for use with remote sensor data: Geological Survey Professional

Paper 964, 28 p.

Anderson, K.E., 1984, Water well handbook: Missouri Water Well and Pump Contractors

Association, Inc., 5th ed., 281 p.

American Society for Testing and Materials (ASTM), 1983, Standard practice for thin-wall tube

sampling of soils, D1587, in 1986 Annual book of ASTM standards: Philadelphia, ASTM,

p. 305-307.

American Society for Testing and Materials (ASTM), 1984, Standard method for penetration test

and split barrel sampling of soils, D1586, in 1986 Annual book of ASTM standards:

Philadelphia, ASTM, p. 298-303.

American Society for Testing and Materials (ASTM), 1992, Standard practice for design and installation of ground water monitoring wells in aquifers, D 5092-90, in ASTM standards on

ground water and vadose zone investigations: Philadelphia, ASTM, p. 122-133.

Bachman, L.J., Shedlock, R.J., and Phillips, P.J., 1987, Ground-water-quality assessment of the

the Delmarva Peninsula, Delaware, Maryland, and Virginia: Project Description: U.S.

Geological Survey Open-File Report 87-112, 18 p.

Barcelona, M.J., Gibb, J.P., and Miller, R.A., 1983, A guide to the selection of materials for monitoring well construction and ground-water sampling: Illinois State Water Survey Contract

Report 327, Champagne, Department of Energy and Natural Resources, 78 p.

Bedinger, M.S., and Reed, J.E., 1988, Practical guide to aquifer-test analysis: Las Vegas, Nev.,

U.S. Environmental Protection Agency, Environmental Monitoring Systems Laboratory,

Office of Research and Development, 81 p.

Chiang, C.Y., Loos, K.R., and Klopp, R.A., 1992, Field determination of geological/chemical

properties of an aquifer by cone penetrometry and headspace analysis: Ground Water,

v. 30, no. 3, p. 428-436.
65

Christenson, S.C., and Parkhurst, D.L., 1987, Ground-water-quality assessment of the Central

Oklahoma aquifer, Oklahoma: Project Description: U.S. Geological Survey Open-File

Report 87-235, 30 p.

Claassen, H.C., 1982, Guidelines and techniques for obtaining water samples that accurately

represent the water chemistry of an aquifer: U.S. Geological Survey Open-File Report

82-1024, 49 p.

Cohen, P., Alley, W.M., and Wilber, W.G., 1988, National water-quality assessment: future

directions of the U.S. Geological Survey: American Water Resources Association, Water

Resources Bulletin, v. 24, no. 6, p. 1147-1151.

Cowgill, U.M., 1988, The chemical composition of leachate from a two-week dwell-time study

of PVC well casing and a three-week dwell-time study of fiberglass reinforced epoxy

well casing: Ground-Water Contamination--Field Methods, ASTM STP 963, A.G.

Collins and A.I. Johnson, eds., American Society for Testing and Materials, Philadelphia,

p. 172-184.

Curran, C.M., and Tomson, M.B., 1983, Leaching of trace organics into water from five common plastics: Ground Water Monitoring Review, v. 3, no. 3, p. 68-71.

Dablow, J.S. III, Walker, G., and Persico, D., 1988, Design considerations and installation

techniques for monitoring wells cased with 'Teflon' PTFE: in Ground-Water Contamination Field Methods, ATSM Special Technical Publication 963, Collins and Johnson, eds.,

ASTM Publication Code Number 04-963000-38, p. 199-205.

Davis, R.E., Foote, F.S., and Kelly, J.W., 1966, Surveying - Theory and practice: New York,

McGraw-Hill, 1,096 p.

Driscoll, F.G., 1986, Groundwater and wells (2d ed.): St. Paul, Johnson Division, 1,089 p.

Garber, M.S., and Koopman, F.C., 1968, Methods of measuring water levels in deep wells:

Techniques of Water-Resources Investigations of the U.S. Geological Survey, book 8,

chap. A1, 23 p.

Gillham, R.W., and O’Hannesin, S.F., 1990, Sorption of aromatic hydrocarbons by materials

used in construction of ground-water sampling wells in Ground Water and Vadose Zone

Monitoring, ASTM STP 1053, D.M. Nielsen and A.J. Johnson, eds., American Society

for Testing and Materials, Philadelphia, p. 108-122.

Gillham, R.W., Robin, M.J.L., Barker, J.F., and Cherry, J.A., 1983, Ground water sampling

bias: American Petroleum Institute, American Petroleum Institute Publication 4367,

Washington, D.C., June, 1983, 206 p.

Gilliom, R.J., Alley, W.M., and Gurtz, M.E., 1995, Design of the National Water-Quality

Assessment Program: occurrence and distribution of water-quality conditions:

U.S. Geological Survey Circular 1112, 33 p.

Hardy, M.A., Leahy, P.P., and Alley, W.M., 1989, Well installation and documentation, and

ground-water sampling protocols for the pilot National Water-Quality Assessment

Program: U.S. Geological Survey Open-File Report 98-396, 36 p.
66

Hewitt, A.D., 1992, Potential of common well casing materials to influence aqueous metal concentrations: Ground Water Monitoring Review, v. 12, no. 2, p. 131-136.

Hewitt, A.D., 1994a, Dynamic study of common well screen materials: Ground Water Monitoring Review, v. 14, no. 1, p. 87-94.

Hewitt, A.D., 1994b, Leaching of metal pollutants from four well casings used for ground-water

monitoring: U.S. Army Corps of Engineers Special Report 89-32, Hanover, New Hampshire, 11 p.

Hirsch, R.M., Alley, W.M., and Wilber, W.G., 1988, Concepts for a national water-quality

assessment program: U.S. Geological Survey Circular 1021, 42 p.

Hodges, R.E., 1988, Calibration and standardization of geophysical well-logging equipment for

hydrologic applications: U.S. Geological Survey Water-Resources Investigations Report

88-4058, 25 p.

Hodges, R.E., and Teasdale, W.E., 1991, Considerations related to drilling methods in planning

and performing borehole-geophysical logging for ground-water studies: U.S Geological

Survey Water-Resources Investigations Report 91-4090, 17 p.

Hollett, K.J., Wilbourn, S.L., and Latkovich, V.J., (compilers), 1994, Proceedings of a U.S. Geological Survey workshop on the application and needs of submersible pressure sensors,

Denver, Colorado, June 7-10, 1994: U.S. Geological Survey Open-File Report 94-531,

53 p.

Jelinski, J.C., 1990, Drive-point sampler: U.S. Geological Survey, WRD, Hydrologic

Instrumentation Facility, Instrument News, Stennis Space Center, Mississippi, no. 51,

December, 1990, p. 12.

Jorgenson, D.G.,1990, Estimating water quality from geophysical logs, in Paillet, F.L., and

Sanders, W.R., eds., ASTM STP 1101: American Society for Testing and Materials,

Philadelphia, p. 47-64.

Keys, W.S., 1990, Borehole geophysics applied to ground-water investigations: U.S. Geological

Survey Techniques of Water-Resources Investigations, book. 2, chap. E2, 150 p.

Koterba, M.T., Wilde, F.D., and Lapham, W.W., in press, Ground-water data-collection protocols and procedures for the National Water-Quality Assessment Program--Collection and

documentation of water-quality samples and related data: U.S. Geological Survey OpenFile Report 95-399.

Latkovich, V.J., 1993, Proceedings of a pressure tranducer-packer workshop, June 25-28, 1991:

U.S. Geological Survey Open-File Report 93-71, 49.

Leahy, P.P. and W. G. Wilber, 1991a, National Water-Quality Assessment Program: U.S.

Geological Survey Open-File Report 91-54, 2 p.

Leahy, P.P., and Wilber, W.G., 1991b, The National Water-Quality Assessment (NAWQA)

Program--A basis for water-resource policy development: Irrigation and Drainage

Proceedings, July 22-26, 1991, IR Div/ASCE, Honolulu, HI, p 711-717.
67

Leahy, P.P., Rosenshein, J.S., and Knopman, D.S., 1990, Implementation plan for the National

Water-Quality Assessment Program: U.S. Geological Survey Open-File Report 90-174,

10 p.

LeBlanc, D.R., Garabedian, S.P., Hess, K.M., Gelhar, L.W., Quadri, R.D., Stollenwerk, K.G.,

and Wood, W.W., 1991, Large-scale natural gradient tracer test in sand and gravel, Cape

Cod, Massachusetts: 1. Experimental design and observed tracer movement: Water

Resources Research, v. 27, no. 5, pp. 895-910.

Lohman, S.W., 1972, Ground-water hydraulics: U.S. Geological Survey Professional Paper

708, 70 p.

Mattraw, H.C., Jr., Wilber, W.G., and Alley, W.M., 1989, Quality-assurance plan for the pilot

National Water-Quality Assessment Program: U.S. Geological Survey Open-File

Report 89-726, 21 p.

Moberly, R.L., 1985, Equipment decontamination: Ground Water Age, v. 19, no. 8, p. 36-39.

Mogg, J.L., 1977, New instrument expands water well technology: Johnson Drillers' Journal,

v. 49, no. 3, p. 1-7.

Munch, J.H., and Killey, R.W.D., 1985, Equipment and methodology for sampling and testing

cohesionless sediments: Ground Water Monitoring Review, v. 5, no. 1, p. 38-42.

Nielsen, D.M., and Schalla, Ronald, 1991, Design and installation of ground-water monitoring wells in Nielsen, D.M., ed., Practical handbook of ground-water monitoring:

Chelsea, Michigan, p. 239-331.

Parker, L.V., 1992, Suggested guidelines for the use of PTFE, PVC and stainless steel in samplers and well casingsin Nielsen, D.M., and Sara, M.N., eds., Current practices in ground

water and vadose zone investigations, ASTM STP 1118: Philadelphia, American Society for Testing and Materials, p. 217-229.

Parker, L.V., Hewitt, A.D., and Jenkins, T.F., 1990, Influence of casing materials on tracelevel chemicals in well water: Ground Water Monitoring Review, v. 10, no. 2, p. 146-

156.

Parker, L.V., and Jenkins, T.F., 1986, Suitability of polyvinyl chloride well casings for monitoring munitions in ground water: Ground Water Monitoring Review, v. 6, no. 3, p. 92-

98.

Parker, L.V., and Ranney, T.A., 1994, Effect of concentration of sorption of dissolved organics

by PVC, PTFE, and stainless steel well casings: Ground Water Monitoring Review,

v. 14, no. 3, p. 139-149.

Patterson, R.J., Frape, S.K., Dykes, L.S., and McLeod, R.A., 1978, A coring and squeezing

technique for the detailed study of subsurface water chemistry: Canadian Journal of

Earth Science, v. 15, p. 162-169.

Pickens, J.F., Cherry, J.A., Grisak, G.E., Merritt, W.F., and Risto, B.A., 1978, A multilevel

device for ground-water samping and piezometric monitoring: Ground Water, v. 16,

no. 5, pp. 322-327.
68

Ranney, T.A., and Parker, L.V., 1994, Sorption of trace-level organics by ABS, FEP, FRE and

FRP well casings: U.S. Army Corps of Engineers CRREL Special Report 94-15, Hanover,

New Hampshire, 31 p.

Rea, A.H., in press. Factors related to water quality in the Central Oklahoma aquifer, In: Christenson, Scott and J.S. Havens (eds.) Ground-water-quality assessment of the Central Oklahoma

aquifer: Results of Investigations. U.S. Geological Survey Open-File Report 93-441.

Reynolds, G.W., and Gillham, R.W., 1986, Absorption of halogenated organic compounds by

polymer materials commonly used in ground water monitors in Proceedings Second Canadian/American Conference on Hydrogeology, Hazardous Wastes in Ground Water--a soluble dilemma, Banff, Alberta, Canada, June 25-29, 1985: Dublin Ohio, National Water Well

Association, p. 125-132.

Reynolds, G.W., Hoff, J.T., and Gillham, R.W., 1990. Sampling bias caused by materials used to

monitor halocarbons in ground water, Envrion. Sci. Technol. 24(1):135-142.

Richter, H.R., and Collentine, M.G., 1983, Will my monitoring well survive down there? - Design

installation techniques for hazardous waste studies, in Nielsen, D.M., ed., 1983, Proceedings

of the Third National Symposium on Aquifer Restoration and Ground-Water Monitoring:

Worthington, Ohio, National Water Well Association, 461 p.

Ritchey, J.D., 1986, Electronics sensing devices used for in situ ground water monitoring: Ground

Water Monitoring Review, v. 6, no. 2, p. 108-113.

Robertson, P.K., and Campanella, R.G., 1986, Guidelines for use, and interpretation of the electronic cone penetration test, (3d ed.): Vancouver, University of British Columbia, Department of Civil Engineering, [175 p.].

Sanders, P.J., 1984, New tape for ground water measurements: Ground Water Monitoring

Review, v. 4, no. 1, p. 38-42.

Scott, J.C., 1989, A computerized data-base system for land-use and land-cover data collected at

ground-water sampling sites in the pilot National Water-Quality Assessment Program: U.S.

Geological Survey Water-Resources Investigations Report 89-4172, 139 p.

Scott, J.C., 1990, Computerized stratified random site-selection approaches for design of a

ground-water-quality sampling network: U.S. Geological Survey Water-Resources Investigations Report 90-4101, 109 p.

Shuter, Eugene, and Teasdale, W.E., 1989, Application of drilling, coring, and sampling techniques to test holes and wells: U.S. Geological Survey Techniques of Water-Resources

Investigations, book 2, chap. F1, 97 p.

Smolley, Mark, and Kappmeyer, J.C., 1991, Cone penetrometer tests and hydropunch sampling -

a screening technique for plume definition: Ground Water Monitoring Review, v. 11, no. 2,

p. 101-106.
69

Sosebee, J.B., Jr., Geiszler, P.C., Winegardner, D.L., and Fisher, C.R., 1983, Contamination

of Groundwater samples with poly(vinyl chloride) adhesives and poly(vinyl chloride)

primer from monitor wells: Hazardous and Industrial Solid Waste Testing: Second Symposium, ASTM STP 805, R.A. Conway and W.P. Gulledge, eds., American Society for

Testing and Materials, p. 38-50.

Stallman, R.W., 1971, Aquifer-test design, observation, and data analysis: U.S. Geological

Survey Techniques of Water-Resources Investigations, book 3, chap. B1, 26 p.

Stites, W. and Chambers, L.W., 1991, A method for installing minature multilevel sampling

wells: Ground Water, v. 29, no. 3, pp. 430-432.

Taylor, T.A., and Dey, J.A., 1985, Bibliography of borehole geophysics as applied to groundwater hydrology: U.S. Geological Survey Circular 926, 62 p.

U.S. Bureau of Reclamation, 1977, Ground Water Manual: U.S. Department of Interior,

Bureau of Reclamation, United States Government Printing Office, Denver, CO., 480 p.

U.S. Environmental Protection Agency, 1987, Handbook on ground-water: EPA/625/6/87/

016, 211 p.

U.S. Geological Survey, 1980, Ground water, chapter 2 of National handbook of recommended methods for water-data acquisition: Office of Water Data Coordination, 149 p.

van der Kamp, G., and Keller, C.K., 1993, Casing leakage in monitoring wells: detection, confirmation, and prevention: Ground Water Monitoring & Remediation, v. 13, no. 4, 136-

141.

Welch, A.H., and Plume, R.W., 1987, Water-quality assessment of the Carson River groundwater basin, Nevada and California: Project Description: U.S. Geological Survey OpenFile Report 87-104, 27 p.
70
Errata

(Open-File Report 95-398)

Ground-Water Data-Collection Protocols and Procedures for the National Water-Quality Assessment Program: Selection, Installation, and Documentation of Wells, and Collection of Related

Data.

Corrections made to the accompanying electronic copy of Open-File Report 95-398 are:

Jan. 24, 1996 Page 31, Table 6, Items (1) and (2) - the percentage for

phosphorus has been changed from 0.4 percent to 0.04 percent.

For comments or questions regarding Open-File Report 95-398, contact Wayne Lapham

(wlapham@usgs.gov) at 703-648-5805.