United States
Environmental
Protection
Agency
Office of Prevention,
Pesticides, And
Toxic Substances
(7501C)
EPA 735-B,93-005c
February 1994
Assessment, Prevention,
Monitoring, and Response
Components of
State Management Plans
Appendix B
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Appendix to the Guidance for Pesticides and
Ground Water State Management Plans
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APPENDIX B:
ASSESSMENT, PREVENTION,
MONITORING, AND RESPONSE
COMPONENTS OF
STATE MANAGEMENT PLANS
IMPLEMENTATION DOCUMENT FOR THE
PESTICIDES AND GROUND WATER STRATEGY
&EPA
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF PESTICIDE PROGRAMS
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Preface
Support for the preparation of this document was provided to EPA's Office of
Pesticide Programs by SRA Technologies, Inc., Research Triangle Institute, and ICF
Incorporated. The document is not intended to provide detailed technical information on
"how to do" the activities that are components of a State Management Plan (SMP).
Rather, this appendix (1) is a resource and reference document that describes where to
go for information in developing components of an SMP; (2) briefly describes factors to
consider and a range of options that States may use in developing approaches that are
appropriate to their local conditions and needs; and (3) provides examples of approaches
that have been used. This appendix provides references and points of contact wherever
appropriate to direct the user to the most useful sources of information. The contents of
this document do not necessarily reflect the joint or separate views and policies of any
EPA program office or of the Agency.
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Acknowledgements
This document was prepared for the U.S. Environmental Protection Agency (EPA),
Office of Pesticide Programs, Field Operations Division. Norma Hughes and
Miriam Romblad served as the EPA Project Officer. Cathleen Cowley Kronopolus and
Jackie Harwood served as the EPA Work Assignment Manager. Linda Hyman Strauss
and Al Havinga served as the EPA lead contacts in coordinating the preparation of the
document.
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Contents
Contents
Chapter Page
Preface
Acknowledgements
1 Introduction 1-1
1.1 Purpose and Scope 1-1
1.2 Roadmap of Appendix B 1-4
1.3 References 1-4
2 Development of Ground Water Protection, Prevention, and Response
Philosophy 2-1
2.1 Ground Water Protection Philosophy 2-2
2.2 Prevention and Response Philosophy 2-3
3 Technical Tools for Assessment and Planning 3-1
3.1 Aquifer Sensitivity and Ground Water Vulnerability Assessment
Methods 3-3
3.1.1 Method Categories 3-5
3.1.2 Selection of Sensitivity/Vulnerability Assessment Methods . 3-18
3.1.3 Documentation and Evaluation of Sensitivity/Vulnerability
Assessment Methods 3-19
3.2 Pesticide Use Evaluations 3-21
3.2.1 Pesticide-Use Profiles Based on Sales or Crop Data 3-22
3.2.2 Voluntary User Surveys 3-23
3.2.3 Commercial Pesticide Usage Surveys . 3-24
3.2.4 Required Recordkeeping . '3-25
3.2.5 Nonagricultural Use Considerations 3-25
3.3 Geographic Information Systems 3-34
3.3.1 Advantages for SMP Development and Implementation . . . 3-36
3.3.2 Implementation Considerations . 3-37
3.4 Defining Reasonably Expected Uses of Ground Water 3-38
3.4.1 Public Process 3-39
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Contents
3.4.2 Defining Reasonably Expected Uses for Ecological Support
and Drinking Water 3-40
3.4.3 EPA's Definition of "Reasonably Expected Uses of Ground
Water" 3-41
3.5 References ; 3-41
4 Prevention Components of SMPs 4-1
4.1 fnterrelatedness of the Prevention, Monitoring, and Response
Components 4-4
4.2 Measures that Protect Ground Water from Pesticide
Contamination '. 4-4
4.2.1 Measures that Control Sources of Direct Pesticide
Contamination of Ground Water 4-6
4.2.2 Use Limitations or Prohibitions 4-10:
4.2.3 Reduction of Leaching Potential 4-15
4.2.4 Measures that Reduce the Quantity and Toxicity of Pesticides
Used and Integrated Pest Management 4-18-
4.3 Implementation Approaches 4-23
4.3.1 Non-Regulatory Efforts 4-24
4.3.2 Regulatory Actions '. . 4-25
4.3.3 Involvement of Each Level of Government . 4-28
4.4 Implementation Considerations 4-30
4.4.1 Effectiveness for Ground Water Protection . 4-30
4.4.2 Economic Costs :....... 4-31
4.4.3 Geographic Extent 4-31
4.4.4 Impacts on Other Media 4-33
4.4.5 Use of Reference Points or Action Levels 4-33
4.5 References ' 4-34
5 Monitoring Elements of SMPs 5-1
5.1 Monitoring Program Scope and Objective 5-3
5.2 Monitoring Design and Justification 5-5
5.2.1 Existing Water-Supply Wells 5-5
5.2.2 Existing Monitoring Wells 5-6
Page ii
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Contents
5.2.3 Existing Observation Wells 5-7
5.2.4 Existing Piezometers 5-7
5.2.5 Development of a New Monitoring Well 5-7
5.2.6 Special Considerations for Ground Water Monitoring in Karst
Terrains 5-10
5.2.7 Special Considerations for Monitoring in Fractured Rock
Terrains 5-11
5.3 Monitoring Protocols 5-11
5.3.1 Baseline Monitoring 5-13
5.3.2 Problem Identification Monitoring , 5-18
5.3.3 Response Monitoring . 5-23
5.3.4 Evaluation Monitoring . 5-23
5.4 Quality Assurance/Quality Control 5-26
5.4.1 QA/QC Plans for Generic SMPs 5-29
5.4.2 Quality Assurance Project Plans for Pesticide SMPs , 5-30
«
5.5 Ground Water Sampling Procedures 5-35
5.5.1 Site Selection 5-36
5.5.2 Sampling Frequency Schedule 5-37
5.5.3 Field Sampling and Measurement Procedures . 5-40
5.5.4 Sample Handling, Custody, and Transport 5-43
5.6 Ground Water Sample Analysis 5-45
5.6.1 Analytic Methods 5-45
5.6.2 EPA Methods ,'. 5-46
5.6.3 Immunoassay Methods 5-50
5.6.4 Methods for Reducing Monitoring Costs 5-51
5.7 References 5-52
t
6 Response Plan ' 6-1
6.1 Relation of Response, Monitoring, and Prevention Components of
an SMP 6-3
6.2 Response Measures 6-3
6.2.1 Implementation of Increasingly Stringent Preventive
Measures 6-4
Page iii
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Contents
6.2.2 Water Supply Treatment and Other Response Mechanisms 6-4
6.2.3 Remediation 6-6
6.3 Determination and Evaluation of Contamination Causes 6-9
6.4 Use of Reference Points or Action Levels 6-10
6.4.1 What is Detection? 6-11
6.4.2 Responding to Detections Below the MCL or HA . 6-13
6.4.3 Responding to Detections At or Above the MCL or HA ... 6-14
6.5 References . 6-15
7 Sources of Technical Information 7-1
7.1 Categories of Technical Information 7-2
7.2 Sources of Information from the U.S. Environmental Protection
Agency (EPA) 7-3
7.2.1 National Survey of Pesticides in Drinking Water Wells .... 7-6
7.2.2 Pesticide Information Network (PIN) , 7-6
7.2.3 Pesticides.in Ground Water Data Base (PGWDB) . 7-7
7.2.4 Comprehensive State Ground Water Protection Program
(CSGWPP) ; 7-7
7.2.5 Nitrogen Action Plan (NAP) '. 7-7
7.2.6 National Estuarine Program (NEP) and Chesapeake Bay
Program 7-8
7.2.7 Clean Water Act Programs 7-8
7.2.8 Safe Drinking Water Act Programs (SDWA) ; 7-9
7.2.9 Federal Reporting Data System (FRDS) . . 7-10
7.2.10 Storage and Retrieval of U.S. Waterways Parametric
Data System (STORET) 7-10
7.2.11 Office of Research and Development (ORD) Ground
Water Research Program 7-10
7.2.12 Special Toxicity Data Bases '7-10
t
7.3 Sources of Information from the U.S. Department of Interior 7-11
7.3.1 U.S. Geological Survey (USGS) 7-11
7.3.2 Fish and Wildlife Service (FWS) 7-12
7.3.3 Additional Sources from the U.S. Department of Interior ... 7-12
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Contents
7.4 Sources of Information from the U.S. Department of Agriculture
(USDA) 7-13
7.4.1 Agricultural Stabilization and Conservation Service (ASCS) . 7-13
7.4.2 Agricultural Research Service (ARS) 7-13
7.4.3 Cooperative State Research Service (CSRS) 7-14
7.4.4 Extension Service (ES) 7-14
7.4.5 National Agricultural Library (NAL) 7-14
7.4.6 Forest Service (FS) 7-14
7.4.7 Soil Conservation Service (SCS) 7-15
7.4.8 Economic Research Service (ERS) and National Agricultural
Statistics Service (NASS) 7-15
7.5 Sources of Information from the National Oceanic and Atmospheric
Administration (NOAA) . . . 7-15
7.6 Other Sources 7-16
7.6.1 Institute for Alternative Agriculture 7-16
7.6.2 Land Stewardship Project 7-16
7.6.3 Conservation Technology Information Center 7-16
7.6.4 National Fertilizer and Environmental Research Center
(NFERC) 7-16
7.6.5 National Pesticide Information Retrieval System (NPIRS) ... 7-17
7.6.6 Fish and Wildlife Information Exchange (FWIE) 7-17
7.6.7 National Center for Food and Agricultural Policy (NCFAP) . 7-17
7.7 Contacts 7-17
7.8 References 7-32
GLOSSARY
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List of Tables
List of Tables.
Table Page
2-1 Summary of Existing Ground Water Protection Programs 2-4
3-1 Description of Statistical Tools (adapted from EPA, 1993) 3-6
3-2 Description of Aquifer Sensitivity Methods (adapted from EPA,
1993) 3-8
3-3 Description of Ground Water Vulnerability Methods (adapted from
EPA, 1993) 3-11
3-4 Examples of Information Available from Some Commercial Market
Survey Organizations 3-24
3-5 Recordkeeping Requirements for Certified Applicators of Restricted
Use Pesticides 3-26
3-6 Summary of Required Pesticide Sale and Use Recordkeeping in
California ,. 3-29
4-1 Examples of Pesticide Management Practices for Ground Water
Protection 4-8
5-1 Basic Design Components for New Monitoring Wells 5-9
5-2 Examples of Baseline Monitoring Programs and Data Bases 5-14
5-3 Examples of Problem Identification Monitoring Studies 5-21
5-4 Examples of Response Monitoring Studies 5-25
5-5 Examples of Evaluation Monitoring Studies -5-28
5-6 SDWA and National Pesticide Survey Analytical Methods for
Pesticides in Ground Water 5-47
5-7 Analytical Methods for Selected Pesticides 5-48
7-1 Selected Sources of Information , , , 7-4
7-2 Sources of Technical Information 7-18
Page vii
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List of Tables
7-3 National Agricultural Pesticide Impact Assessment Program List of
State Liaison Representatives 7-23
7-4 Contact Information for National Agricultural Statistics Services
(NASS) State Statisticians 7-31
Page viii
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List of Figures
List of Figures
Figure Page
1-1 Sources of Guidance on SMPs 1-3
3-1 Range of Methods for Assessing Aquifer Sensitivity and Ground
Water Vulnerability 3-2
4-1 Relationship Among Prevention, Monitoring, and Response 4-5
5-1 Range of Technical Tools for Developing a Monitoring Program ... 5-2
5-2 Typical Monitoring Well Detail . 5-8
5-3 Baseline Monitoring 5-16
5-4 Problem Identification Monitoring 5-22
5-5 Response Monitoring 5-24
5-6 Evaluation Monitoring 5-27
6-1 Range of Technical Tools for Developing a Response Plan 6-12
Page ix
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Chapter 1
Chapter 1
Introduction
The general goal of EPA's Pesticides and Ground Water Strategy is to manage the
use of pesticides in order to prevent unreasonable adverse effects to human health and
the environment and to protect the environmental integrity of the nation's ground water
resources. Prevention is the central principle of EPA's approach to managing pesticide
use in order to protect ground water resources. Through the implementation of State
Management Plans (SMPs) for pesticides, States may promote the environmentally sound
use of pesticides that might otherwise pose an unreasonable risk to ground water
resources. Although EPA can require SMPs only through a chemical-specific regulatory
action, States are strongly encouraged to take the initiative voluntarily to develop Generic
SMPs that establish the framework for SMPs that address specific pesticides (Pesticide
SMPs) even before EPA requires SMPs through a chemical-specific regulatory action.
The Guidance for Pesticides and Ground Water State Management Plans, with its
Appendices, establishes the components of SMPs and provides approaches and
methods to assist States in developing and implementing SMPs.
1.1 Purpose and Scope
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) provides EPA with
the regulatory authority to require States to develop SMPs to continue to use a pesticide
that would otherwise pose an unreasonable risk and be unavailable due to cancellation
or lack of registration. Through a chemical-specific regulatory action under FIFRA Section
3 or 6, an SMP (referred to as a Pesticide SMP) becomes a required condition for the
sale and use of a pesticide. Because States may be required to develop more than one
Pesticide SMP, States may find it beneficial to develop a Generic SMP that contains
components common to most Pesticide SMPs. EPA encourages States to develop
Generic SMPs, but they are not required. If a State decides to develop a Generic SMP
and seek EPA concurrence, the Generic SMP must address all 12 SMP components in
the detail necessary to obtain EPA concurrence.
EPA has identified the following 12 components that must be addressed in'both
Generic and Pesticide SMPs:
1. State's philosophy and goals toward protecting ground water;
2. Roles and responsibilities of State agencies;
3. Legal authority;
4. Resources:
5. Basis for assessment and planning;
6. Monitoring;
7. Prevention actions;
Page 1-1
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Chapter 1
8. Response to detections of pesticides;
9. Enforcement mechanisms;
10. Public awareness and participation;
11. Information dissemination; and
12. Records and reporting.
The extent to which each of these necessary components of a Generic or Pesticide
SMP is addressed will depend on the State's ground water protection philosophy, ground.
water vulnerability, degree of pesticide use, agronomic practices, and the use and value
of its ground water. The type and level of information included in the SMP must be
sufficient to result in the adequate implementation of the SMP, given the unique
characteristics of the State/ The individual States are the best sources of information
regarding the circumstances surrounding development and implementation of this
program. The Guidance for Pesticides and Ground Water State Management Plans and
a support document, Appendix A: Review. Approval, and Evaluation of State
Management Plans, provide guidance on the type and level of information that may be
necessary to address each of the 12 components adequately.
This support document, Appendix B: Assessment. Prevention. Monitoring, and
Response Components of State Management Plans, is a guide to technical information
that will assist States in the development of the assessment, monitoring, prevention, and
response components of SMPs. The development of plans to determine and monitor the
quality of the ground water resources, to prevent unreasonable adverse effects to human
health and the environment, to protect the environmental integrity of the nation's ground
water resources, and to respond to detections of pesticides in ground water are
technically complex projects. This support document presents a range of approaches
that may help guide States in the development of SMPs. This appendix provides an
overview of the technical considerations that should be addressed in the development of
SMPs; it does not attempt to provide a complete discussion of complex technical matters.
Furthermore, this appendix cannot be exhaustive; prevention, monitoring, and response
strategies other than those specifically described also may be appropriate and acceptable
in SMPs. Finally, States also need to recognize the importance of involving local entities
(e.g., local extension offices, local planning offices, etc.), as well as all applicable State
agencies, in selecting and implementing the appropriate tools or mechanisms for
protecting ground water resources from pesticide contamination.
i
Appendix B represents EPA guidance to States on developing Generic and
Pesticide SMPs. The language contained in this document on the 12 components of a
Pesticide SMP will also be proposed for public comment in an upcoming regulation
specifying pesticides for which a Pesticide SMP will be required. This guidance
document does not establish a binding norm -- Agency decisions to approve or
disapprove Pesticide SMPs will be made on a case-by-case 'basis by applying the
regulation to the specific facts of the case. '
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Figure 1
Sources of Guidance on SMPs
Guidance for
Pesticides and
Ground Water
State Management
Plans
Review, Approval,
and Evaluation
of State
Management
Plans
1. Philosophy and goals
2. Roles and responsibilities
3. Legal authority
4. Resources
5. Assessment and planning
6. Monitoring
7. Prevention
8. Response
9. Enforcement mechanisms
10. Public awareness and participation
11. Information dissemination
12. Records and reporting
Assessment,
Prevention,
Monitoring, and
Response
Components of
State Management
Plans
Appendix
B
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Chapter 1
1.2 Roadmap of Appendix B
This appendix is organized as follows:
Chapter 2 gives an introduction to philosophies of ground water
protection and response and a summary of EPA's current ground
water protection programs.
Chapter 3 gives a description of technical tools and sources of
.technical information for assessment and planning. It includes
aquifer sensitivity and vulnerability assessment methods, techniques
and sources to assess pesticide use, and spatial data base
methodologies.
Chapter 4 provides support for the development of the prevention
component of a Generic or Pesticide SMP.
Chapter 5 provides support for the development of the monitoring
component of a Generic or Pesticide SMP.
Chapter 6 provides support for the development of the response
component of a Generic or Pesticide SMP.
Chapter 7 is a guide to sources of technical information.
1.3 References
U.S. EPA. Office of Pesticides and Toxic Substances, Office of Pesticide Programs,
October 1990. Pesticides and Ground Water Strategy. EPA 21T-1022.
U.S. EPA. Office of the Administrator, July 1991. Protecting The Nation's Ground Water:
EPA's Strategy for the 1990s. EPA21Z-1020.
Page 1-4
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Chapter 2
Chapter 2
Development of Ground Water Protection,
Prevention, and Response Philosophy
The goal of EPA's Pesticides and Ground Water Strategy is to prevent
contamination of ground water resources that presents an unreasonable risk of adverse
effects to human health and the environment resulting from the normal, registered use of
pesticides, by taking appropriate actions in vulnerable areas. In determining appropriate
prevention and protection strategies, EPA will also consider the use, value, and
vulnerability of ground water resources. Because pesticides have extensive beneficial
uses, EPA is seeking through SMPs to promote the environmentally sound use of
pesticides that might otherwise not be available due to chemical-specific regulatory
actions.
States should consider EPA's goal in formulating approaches to protect ground
water resources and manage pesticides that present health or environmental risks. While
States are not constrained to follow EPA's philosophy, goals, and priorities as set forth
in the Pesticides and Ground Water Strategy. State programs must be at least as
protective. SMPs will vary based on the extent of the State's unique hydrogeologic and
institutional characteristics, including its ground water protection philosophy, the sensitivity
of its ground water, degree of pesticide use, agronomic practices, and use and value of
ground water. Therefore, a critical component of an SMP is the statement of a State's
philosophy concerning ground water protection and its philosophy of response to ground
water contamination resulting from normal uses of pesticides. Successful implementation
of prevention, monitoring, and response plans ultimately depend on the establishment of
clear ground water protection and response goals.
The Guidance for Pesticides and Ground Water State Management Plans specifies
that both a Generic and a Pesticide State Management Plan should include:
A statement that addresses which ground waters will be protected
and the degree of protection which will be achieved under the SMP. ,
The stated goal of protection efforts. The goal can use EPA
established reference points, a more stringent standard than EPA
established reference points, or maintain and protect ground water
at pristine quality.
The balance of this chapter discusses topics involved in the ground water
protection and response philosophy.
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Chapter 2
2.1 Ground Water Protection Philosophy
The State's ground water protection philosophy defines the waters to be
considered in assessment, prevention, monitoring, and response plans. This philosophy
is consistent with the philosophy contained in the States' Comprehensive State Ground
Water Protection Program philosophy and addresses both the ground waters to be
protected and the degree of protection to be achieved under the SMP. In accordance
with EPA's Ground Water Strategy, ground water protection approaches should, at a
minimum, be directed toward:
Currently used and reasonably expected sources of drinking water;
and
Ground water that is closely hydrologically connected to surface
waters affecting the integrity of associated ecosystems.
A State may set additional priorities for ground water protection based on its actual or
potential vulnerability. The determination of ground water use, value, and vulnerability
involves combining information on site-specific hydrogeologic conditions with information
on ground water use and land-use practices that might influence ground water quality.
Determinations of use and value require additional information such as the water quality,
yield, accessibility, connection to important ecosystems, and existence of other more
readily available or higher quality supplies.
States may implement such
differential protection philosophies
through case-by-case assessments or,
for example, through a ground water
classification system. Most States have
already established some form of ground
water classification system. The
Pesticides and Ground Water Strategy
presumes that a major focus of ground
water protection efforts will be on current
and reasonably expected sources of
drinking water and that States are in an
appropriate position to judge the future
uses of their ground water resources.
Recognizing the local variability of
ground water resources and the
complexity of predicting ground water
contamination, ground water protection
methods, Includina'
An example of a use-based priority system
to address the protection of ground water
is the system proposed by the Texas
Ground Water Protection Committee. In
this system, first jpriprity is given to aquifers
that supply current or future sources of
drinking water. Moderately saline ground
water supplies are given second priority in
the Texas protection hierarchy because of
their potential for/future use and the
possibility that they are connected
hydraulically with ; first-priority waters.
(Texas Ground ;Water Protection
Committee. ..,* draft Generic State
; Management Pian for Agricultural
Chemicals in Ground Water. June, 1991.).
may be approached through a number of
Page 2-2
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Chapter 2
Pollution prevention programs;
Source control programs;
Siting controls;
Wellhead protection programs;
Protection of future public water-supply areas; and
Protection of aquifer recharge areas.
A number of EPA programs are designed to protect ground water resources. Some of
these programs may provide grants to assist States in developing their own activities.
Table 2-1 highlights the EPA programs that may be pertinent to SMP development.
Measures that protect ground water from contamination by pesticides are discussed in
Chapter 5. .
2.2 Prevention and Response Philosophy
In the context of this document, the term "response" includes actions initiated after
a pesticide is detected in ground water, as well as actions taken when the concentration
of a pesticide reaches or exceeds a reference level (Chapter 6). As stated in the
Pesticides and Ground Water Strategy, the point of failure for adverse health effects will
be the maximum contaminant level (MCL) or long term health advisory set for the
pesticide. The point of failure for prevention of adverse ecological effects will be the
Water Quality Standards under the Clean Water Act.
A State's ground water protection goal affects the degree of response necessary following
the detection of pesticides in ground water. Examples of States' ground water protection
goals are illustrated below.
Minnesota's ground water protection goal stresses preventing degradation. State law
requires the maintenance of ground water in its natural state, implementation of
preventive measures wherever practicable, and the development of new technologies
and methods where current preventive measures are inadequate. Minnesota Statute
103H.001.
Michigan has a nondegradation goal for all usable aquifers. A nondegradation
standard is established for all aquifers that provide water for individual, public, industrial,
or agricultural supplies. Part 22, Rules of the Michigan Water Resources Commission
Act (1929).
Wisconsin sets enforcement standards and preventive action limits for a number of.
potential ground water pollutants. Regulatory actions are instituted if the ground water
concentration of a pesticide attains or exceeds an established standard or limit, as
detected from a community, private, or monitoring well (Wisconsin Statutes, Chapter
161). .
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Table 2-1. Summary of Existing Ground Water Protection Programs
Program title
Comprehensive
State Ground Water
Protection Program
Wellhead Protection
Program
Nonpoint Source
(NPS) Programs
Sold Source Aquifer
Program
Regulatory
Authority
Through no direct
statutory authority, the
program derives
authority to protect
ground water from CWA
§106 and §319, SDWA
§1424(e) and §1428,
CERCLA, RCRA, and
FIFRA
Safe Drinking Water Act
Amendments of 1986,
§1428
Clean Water Act, §319
Safe Drinking Water Act
of 1986, §1427
Description
Focuses on efficient and effective
ground water protection through
cooperative, consistent, and
coordinated operation of all
relevant federal, State, and local
programs within a State
Focuses on protecting ground
water used for public water
supply
Requires States to describe the
nature, extent, and causes of
NPS pollution and report State
programs to control this
pollution; also requires States to
identify best management
practices and plans for their
implementation
Allows EPA to designate an
aquifer as a sole or principle
source of drinking water
Components
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Consists of a set of six strategic activities:
(1) establish goal; (2) establish priorities,
based on characterization of the resource,
identification of sources of contamination, and
programmatic needs; (3) define roles,
authorities, responsibilities, resources, and
coordinating mechanisms; (4) implement
necessary activities; (5) information collection
and management; and (6) public participation
Delineation of wellhead protection areas
identification of contamination sources
Management approaches to differentially
manage drinking water supplies
NPS Assessment Report
NPS Management Program
Aquifer delineation and use evaluation
\
Management approaches to protect vulnerable
aquifers
Designated aquifers require EPA review of
federally funded projects to assure protection
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Table 2-1. Summary of Existing Ground Water Protection Programs (continued)
Program title
Regulatory
Authority
Description
Components
Public Water
System Supervision
Safe Drinking Water Act
State supervision of public water
systems to prevent human
exposure to waterborne
contaminants
Ground water monitoring and treatment
Monitoring waivers contingent upon
vulnerability assessment
Implementation of well and ground water
protection measures
UtC Program:
Class V Wells
(Agricultural
drainage wells and
irrigation return flow
wells)
SDWA, §1421-1426
Program to protect underground
sources of drinking water
» Development of agricultural best management
practices to ensure agricultural drainage wells
do not affect drinking water sources
Coastal Nonpoint
Source Program
Coastal Zone
Reauthorization
Amendments of 1990,
§6217
Development of State programs
to ensure implementation of non-
point source management
measures
Pesticide management activities
Chesapeake Bay
Program
CWA,§117
Development and implementation
of programs to restore and
enhance Chesapeake Bay
Development of agricultural BMPs
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Chapter 2
The Pesticides and Ground Water Strategy states that prevention of contamination
and protection of the ground water resource is the central principle of EPA's approach
to managing pesticide use. Specifically, the Strategy emphasizes the prevention of
contamination of ground water resources that presents an unreasonable risk of adverse
effects to human health and the environment resulting from the normal, registered use of
pesticides, by taking appropriate actions in vulnerable areas. The State's response
philosophy will provide direction to State agencies in determining what actions will be
needed when 1) a pesticide is found, 2) pesticide concentrations increase over time, or
3) pesticide concentrations approach the reference point. This philosophy will also
provide direction to State agencies in determining what actions will be needed if pesticide
contamination reaches or exceeds the reference point.
EPA recommends that a State develop and implement a response philosophy that.
reflects its ground water protection philosophy, its aquifer sensitivity, and its history of
pesticide use. Action levels which trigger responses should be percentages of the MCL,
consistent with the level of ground water protection chosen by the State through its
ground water protection philosophy. The development of the response component of
SMPs and response actions are discussed in Chapter 6.
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Chapter 3
Chapter 3
Technical Tools for Assessment and Planning
The first technical component of both a Generic and a Pesticide SMP established
by the Guidance for Pesticides and Ground Water State Management Plans is that the
State establish its basis for assessment and planning. This requires that a State have
adequate knowledge of its unique hydrogeologic settings, pesticide usage patterns, and
agronomic practices. EPA, as part of its technical assistance program, will supply
pesticide-specific information such as persistence and mobility data, detection limits,
analytical methodology, and monitoring information. This information can assist States
in developing the assessment and planning portions of an SMP.
A number of technical tools and technical information sources exist on aquifer
sensitivity/ground water vulnerability, pesticide usage, and cropping patterns. In addition,
different tools for organizing information, may be helpful to States in setting priorities for
monitoring, prevention, and response efforts. States should use the tools discussed in
this chapter to facilitate the development and implementation of management plans in
accordance with the guidelines presented in Appendix A. Tools such as aquifer sensitivity
assessments, pesticide use evaluations, and spatial data bases can be used in SMPs in
a broad range of alternative combinations. Figure 3-1 illustrates these combinations,
though it does not represent the full spectrum of alternatives. In addition, a State may
choose to combine the elements in any number of ways, mixing, for example, selective
assessment of ground water vulnerability with detailed pesticide usage information and
a hybrid form of representation of the data. States should note that the methods
presented in this chapter may not be applicable to all situations across States due to the
unique circumstances that occur in each State. These tools and other sources of
technical information are described in the following sections.
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Figure 3-1. Range of Methods for Assessing Aquifer Sensitivity and Ground Water Vulnerability
Pesticide
SMPs
Increasing
Detail and
Precision
I
Generic
SMPs
Aquifer Sensitivity
Full assessment of State aquifer
sensitivity at sub-county level
Apply aquifer sensitivity simulation
method to test management options
Apply hybrid assessment method to
determine teachability of specific
pesticide(s)
Assessment of ground water
vulnerability for areas of high ground
water use and value
Apply aquifer sensitivity screening
method at the State level
Use reports of prior applications of
assessment methods
Use reports of ground water
classification based on
hydrogeologic factors
Ground Water Vulnerability
Full description of State pesticide
use and cropping practices at sub-
county level
Description of geographic use,
application rates, application timing,
application method for particular
pesticide
Acquisition of accurate pesticide use
data for entire State that is updated
periodically
Acquisition of pesticide use data for
limited areas of State that is updated
infrequently
Use of current State records and
non-State sources
Use of reports of prior assessments
of usage
Representing Assessments of
Aquifer Sensitivity and
Ground Water Vulnerability :
Full GIS mapping of State at sub-
county level
Mixed GIS and topographic maps
(i.e., GIS mapping of priority areas
at sub-county level)
Computer data base (e.g., indexed
by latitude and longitude)
Topographic maps documented
with transparent overlays
Topographic maps documented
with field notes
Field notes
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Chapter 3
3.1 Aquifer Sensitivity and Ground Water Vulnerability Assessment
Methods
The Guidance for Pesticides Ground Water State Management Plans states that
the extent to which each of the 12 components of an SMP is addressed will depend on,
among other factors, the State's aquifer sensitivity and ground water vulnerability efforts.
States need to consider the sensitivity and vulnerability of their ground water resources
to pesticides in order to develop appropriate preventive actions. A State may also
establish priorities based on the magnitude of risks and the costs of prevention or
remediation actions, provided these priorities are consistent with the overall goal of the
SMP. Both a Generic and a Pesticide SMP should:
Discuss the State's approach and activities to assess vulnerability
(considering factors such as pesticide usage, soil type, depth to
ground water, aquifer material, precipitation, and irrigation use) on
a sub-county level1 for the geographic area in which the State
intends to allow pesticide use.
In addition, the use of monitoring (see Component 6), modeling,
other geographic planning methods or tools, such as Geographic
Information Systems (GIS), or work developed by other programs
used in developing the approach should be described. Sources of
the above data must be identified. Assessment and planning efforts
should utilize and integrate the data available from ongoing State
and federal assessment and mapping programs such as those
available from the USGS and USDA's Soil Conservation Service.
Discuss how the State will determine current or reasonably expected
sources of drinking water (taking into account factors such as land
use, remoteness, quality and/or availability of alternative water
supplies) and ground water that is hydrologically connected to
surface water. If a State is affording priority protection to all ground
water no matter the use and value, as many States are, then the
State may not have to delineate and define these.
Discuss how the State's assessment of ground water vulnerability ,
and monitoring, and the use and value of ground water, will be used
1 Both the General Accounting Office (GAO), in its report, Groundwater Protection.
Measurement of Relative Vulnerability to Pesticide Contamination, and EPA, in the
National Pesticide Survey Phase II Report, have reported that assessing vulnerability on
the county level generally is not useful in predicting the vulnerability at smaller scales.
Therefore, vulnerability assessments developed for State Management Plans should
consider including sub-county level data, rather than county level data, based on factors
discussed in Section 3.1.2.
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Chapter 3
to set priorities for protection activities, design and implement
prevention and response programs, and determine and evaluate the
effectiveness of management measures.
For example, the SMP may discuss how a combination of modeling
and monitoring will be used to determine what management
practices should be employed in those areas. Some States may
choose to use information developed by one agency on pesticide
use and cropping practices in combination with hydrogeologic
sensitivity maps produced by another agency to determine specific
ground water protection management measures to be implemented
in vulnerable areas. A State also may decide to place a moratorium
on pesticide use within Wellhead Protection Areas, critical recharge
areas, or highly valued aquifers.
Identify the limitations of the assessment and discuss how those
limitations are taken into account in the design of prevention and
response programs. For example, if a State applies prevention
measures on broad regional or county-level designations, then sub-
county level.assessments may not be needed, but the State should
explain why the measures chosen are likely to be adequate to meet
program goals. Conversely, if a State plan allows sub-county or
farm-level distinctions in applying prevention measures in order to
avoid overregulation, it should explain the basis for making such
distinctions, and how protection goals will be met.
Note: The State's assessment and priority should reflect the SMP goal
(Component 1) and should be at a level that complements
monitoring (Component6), prevention (Component?), and response
(Component 8) activities. Over time, new or changed information
from monitoring and on-going assessment activities should be used
to refine and update the assessment.
In addition to the Generic Plan Criteria listed above, a Pesticide Plan must:
Describe the State's available pesticide use data (e.g., geographic
use, application rates) and how it will be factored into assessing
vulnerability.
Aquifer sensitivity is the relative ease with which a contaminant (in this case a
pesticide) applied on or near a land surface can migrate to the aquifer of interest. Aquifer
sensitivity is a function of the intrinsic characteristics of the geologic materials in question,
any overlying saturated materials, and the overlying unsaturated zone. Sensitivity is not
dependent on agronomic practices or pesticide characteristics. Ground water
vulnerability is the relative ease with which a contaminant (in this case a pesticide)
applied on or near a land surface can migrate to the aquifer of interest under a given set
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Chapter 3
of agronomic management practices, pesticide characteristics, and aquifer sensitivity
conditions.
Section 3.1.1 summarily reviews readily accessible sensitivity and vulnerability
assessment methods. Section 3.1.1 identifies and discusses method categories and the
methods that comprise those categories; Section 3.1.2 identifies factors to consider in
selecting methods; and Section 3.1.3 discusses the documentation and evaluation of
assessment methods. The reader should note that Section 3.1 does not provide
extensive information on how to use the methods.
3.1.1 Method Categories
A number of methods have been developed in the last decade that assess aquifer
sensitivity and ground water vulnerability to pesticide contamination. Research is ongoing
to perfect some of these methods and to determine which ones perform most accurately
in different situations to predict pesticide contamination. Federal agencies and other
organizations are currently reviewing many of these methods (Section 3.1.3). The Ground
Water Protection Division of EPA's Office of Ground Water and Drinking Water grouped
the methods into the following two categories:
(1) Aquifer sensitivity methods; and
(2) Ground water vulnerability methods.
Pesticide leaching methods, a subcategory of ground water vulnerability methods, require
pesticide-specific and soil-specific information, and thus incorporate intrinsic
hydrogeological data and pesticide characteristics. Various statistical tools supplement
sensitivity and vulnerability methods and serve to analyze relationships of one or more
hydrogeologic factors to known occurrences of pesticides in ground water. Selected
statistical tools are provided in Table 3-1. The information used to summarize these
methods was largely derived from the EPA Technical Assistance Document (TAD)
A Review of Methods for Assessing Aquifer Sensitivity and Ground Water Vulnerability to
Pesticide Contamination developed by the Office of Ground Water and Drinking Water
(September 1993).
Aquifer Sensitivity Methods
The methods under this category consider only hydrogeologic factors and they do
not consider pesticides or management factors.
Aquifer sensitivity methods use hydrogeologic characteristics to determine an
aquifer's intrinsic susceptibility to pesticide contamination. These methods involve either
the comparison of areas of known pesticide contamination to criteria judged to represent
conditions that are sensitive to contamination, or the calculation of a rating or numerical
score for each area. Methods that generate scores are designed to provide a relative
measure of the sensitivity of one area compared to other areas. The Leachability Classes
of Kansas Soils method is one example of a comparison method. Examples of scoring
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Table 3-1. Description of Statistical Tools
(adapted from EPA, 1993)
Nainie of Method
Author (s) and date:
Multiple Regression
Statistical Analyses
J. Steichen, J. Koeliker,
D. Grosh, A. Heiman,
R. Yearout
(1988)
Multiple Regression
Statistical Analyses
H. Chen, D. Druliner
(1987)
Discriminant Statistical
Analysis/So II taxonomy and
Surveys
R.R. TesiO, T. Younglove,
M.R. Peterson, D.L Sheeks,
R.E. Gallavan
(1988)
Contact Address
Agricultural Engineering
Department
Kansas State University
Manhattan, Kansas 66502
U.S. Geological Survey
406 Federal Building
100 Centennial Mall
North Lincoln, Nebraska 68508
Environmental Hazards
Assessment Program
University of California
Riverside, California 92521
Method Description
The method consists of a multiple regression model used to relate
pesticide concentrations in ground water to the age of a well, land
use in the vicinity of the well, and the distance to the closest possible
source of pesticide contamination.
This multiple regression method was used to describe results of
existing ground water contamination .and the factors affecting that
contamination within six study areas in Nebraska. The researchers
focused on nine independent variables including: hydraulic gradient;
hydraulic conductivity; specific discharge; depth to water; well depth;
annual precipitation; soil permeability; irrigation-well density; and
annual nitrogen fertilizer use.
This method uses a multivariate statistical approach (Fisher's Linear
Discriminant analysis) with soil taxon units to delineate sensitive
areas. The method utilizes soil survey reports, the U.S. rectangular
coordinate system, and available data from ground water and
pesticide analyses.
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Chapter 3
methods include Agricultural DRASTIC, Wisconsin's Ground Water Susceptibility Project,
and SEEPAGE. Table 3-2 briefly describes a number of aquifer sensitivity methods.
Ground Water Vulnerability Methods
Ground water vulnerability methods include pesticide leaching methods (discussed
earlier), pesticide use/aquifer sensitivity methods, and computer simulation models.
Pesticide use/aquifer sensitivity methods involve combining pesticide use information and
the results of an aquifer sensitivity method. Computer simulation models involve the fate
and transport of pesticides in the soil and/or aquifer systems and contain mathematical
equations that describe the processes or phenomena related to pesticide transport.
Examples of simulation models are described in Table 3-3. For a more detailed
discussion, see EPA's Technical Assistance Document (TAD), A Review of Methods for
Assessing Aquifer Sensitivity and Ground Water Vulnerability to Pesticide Contamination
(U.S. EPA, 1993).
Wisconsin's Ground Water Susceptibility Project. The Wisconsin Department of
Natural Resources (in cooperation with the U.S. Geological Survey [USGS], the Wisconsin
Geological and Natural History Survey, and the University of Wisconsin) evaluated
hydrogeological factors that influence the contamination sensitivity of Wisconsin's ground
water. Five factors were identified as important in determining the ease with which a
contaminant can be transported through overlying materials into the ground water.These
factors are 1) depth to bedrock, 2) type of bedrock, 3) soil characteristics, 4) depth to
water table, and 5) characteristics of the surficial deposits. A composite ground water
contamination susceptibility map was prepared for the State (1:1,000,000). The map is a
composite of hydrogeologic data only and does not incorporate individual characteristics
of a specific contaminant or the subsurface release of a contaminant. State agencies use
the composite map to decide where further study on ground water impacts is needed, and
to make sound ground water management and land use decisions. The map is limited,
as it is compiled from very generalized Statewide information at a small scale (i.e., the map
cannot be used for siting disposal facilities or locating an industry).
Kansas' Use of an Aquifer Sensitivity Method. Kansas devised a classification
system to account for protection offered from soils that overlie the aquifers in Kansas. This
classification system relied on an aquifer sensitivity method to group Kansas soils into four
classes of susceptibility based on soil texture and water infiltration rate (permeability).
Coarse-textured soils were generally considered to be more susceptible to pesticide
leaching than fine-grained soils. Emphasis was placed on the limiting soil (e.g., highest
clay content or lowest permeability) in the horizon. A leaching susceptibility map of Kansas
soils was prepared based on the general soils map available from the National Cooperative
Soil Survey. ' ' '....'. -.::,-;,,:,: V::;'-- ,.. ,,",.". '". ,':.;:;:::-... '-
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Table 3-2. Description of Aquifer Sensitivity Methods
(adapted from EPA, 1993)
Name of Method
Author(s) and date:
Agricultural DRASTIC
L Aller, T, Bennett, J.H. Lehr,
R.J. Petty (1985)
AQUIPRO
R.N. Passero, F.J. Cohen,
S.J. Dulaney, P.M. Half,
H. Moaddel (1988)
Greater Denver Ground
Water Sensitivity
Assessment
G. Hearno, M. Wireman,
A. Campbell, S. Turner,
G. Ingersoll (1992)
Idaho's Ground Water
Vulnerability Project
Idaho Department of Health
and Welfare (1991)
Contact Address
U.S. EPA, Robert S. Kerr,
Environmental Research
Laboratory, Ada, Oklahoma
74820
Center for Water Research,
Department of Geology,
Western Michigan University,
Kalamazoo, Michigan 49008
United States Geological
Survey, Water Resources
Division, Federal Center,
Denver, Colorado 80225
Idaho Department of Health and
Welfare, Division of
Environmental Quality > 1410 N.
Hilton, Statehouse Mall, Boise,
Idaho 83720-9000
Method Description
DRASTIC is an acronym for a ranking system that evaluates seven
hydrologic factors. Each factor is independently weighted and then
added together to form a numerical Index. This index represents the
areas' relative degree of pollution potential by pesticides compared
to other areas.
AQUIPRO was developed as an alternative aquifer Vulnerability
ranking system for use in Southwest Michigan where glacial drift
aquifers exist. Unlike DRASTIC, AQUIPRO is based on the
assumption that clays and clayey glacial sediment provide natural
protection for glacial aquifers. This method uses a relative ranking
system. It accounts for the weighted depth of the well and the
weighted average thickness of the protective clay and clayey glacial
sediments and confining and semi-confining bedrock types. The
method has been used to indicate aquifer vulnerability/protective
scores for individual wells and is currently being revised.
Geology, depth to water, soils, and elevation data were processed to
produce maps of seven hydrogeologic factors. Spatial and attribute
data for these maps were stored and processed using GIS software
to produce a map depicting sensitivity of the uppermost aquifer.
Each sensitivity map unit is described in quantitative terms.
This method uses a modified Agricultural DRASTIC scoring system.
Modifications include: 1) a large amount of data on well depths;
2) more detailed soil data; 3) incorporation of irrigation as the largest
contributor to ground water recharge; 4) deletion of topography as a
factor; and 5) subdivision of the soil characteristics factor into four
sub-factors.
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Table 3-2. Description of Aquifer Sensitivity Methods (continued)
(adapted from EPA, 1993)
Name of Method
Author(s) and date:
Contact Address
Method Description
teachability Classes of
Kansas Soils
D.E. Kissel, O.W. Bidwell,
J.F. Kientz (1982)
Kansas State University, Kansas
Agricultural Experiment Station,
Manhattan, Kansas 66502
This method groups Kansas soils into four classes of susceptibility.
Susceptibility is based on the soil profile texture and water infiltration
rate.
Minnesota's Geologic
Sensitivity Methods
Geologic Sensitivity
Workgroup, Minnesota
Department of Natural
Resources (1991)
Geologic Sensitivity Workgroup,
Minnesota Department of
Natural Resources
The Minnesota method applies geologic sensitivity criteria using one
to three levels of assessment. The geologic sensitivity criteria are
five overlapping ranges of known or estimated vertical travel times
that have been assigned relative sensitivity ratings from very high to
very low. A Level 1 assessment estimates the sensitivity of the water
table aquifer using surface and near-surface information. A Level 2
assessment estimates the sensitivity of the water table aquifer using
information from the entire vadose zone. A Level 3 assessment
evaluates the sensitivity of deep, confined aquifers.
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Potential for Contamination
of Shallow Aquifers In Illinois
R.C. Berg, J.P. Kempton,
Keros Cartwright (1984)
Illinois Department of Energy
and Natural Resources, State
Geological Survey Division,
Champaign, Illinois 61820
This method consists of two maps representing the potential for
contamination of shallow aquifers by 1) land burial of wastes and 2)
surface and near-surface waste disposal. Geologic materials to
depths of 20 and 50 feet were differentiated by thickness, texture,
permeability, and stratigraphic position to construct geologic stack-
unit maps. The maps (1: 500,000) show the distribution of geologic
material sequences and their comparative ratings. Each sequence is
rated for the susceptibility of its aquifers to contamination from waste
disposal practices. The land burial map of municipal wastes shows
18 sets of geologic sequences, whereas the surface and near-
surface waste disposal map shows 13 sets of geologic sequences.
Potential disposal sites should be investigated in the field on a site-
specific basis.
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Table 3-2. Description of Aquifer Sensitivity Methods (continued)
(adapted from EPA, 1993)
tf ame of Method
Authoir(s) and date:
SEEPAGE
J.S. Moore (1988)
South Dakota Aquifer
Contamination Vulnerability
Maps
Q. Lemme, C.G. Carlson*
B.R. Khakural, L Knutson,
L. Zav*!skey (1989)
Wisconsin Soil Attenuation
Potential
K.J. Gates, F.W. Madison
(1990)
Wisconsin's Ground Water
Susceptibility Project i
Wisconsin Department of
Natural Resources (WDNR)t
Wisconsin Qebiogical and
Natural History Survey (1987)
Contact Address
U.S. Department of Agriculture,
Soil Conservation Service,
Northeast National Technical
Center
Chester, Pennsylvania
Plant Science Department,
South Dakota State University
and U.S. Department of
Agriculture, Soil Conservation
Service
Brookings, SD 57007-001
Nutrient and Pest Management,
University of Wisconsin-
Extension, Madison, Wisconsin
53706
WDNR Bureau of Water
Resources Management
P.O. Box 7921
Madison, Wisconsin 53707
Method Description
This method uses a relative ranking system for seven soil/aquifer
parameters. Site Index Numbers (SINs) are calculated for different
areas and compared to determine the degree of aquifer sensitivity.
The method accounts for whether the potential source of the
contaminant is concentrated or dispersed.
This method integrates soil, topographic and geologic data to
develop sensitivity values for surface water and aquifer
contamination. Drilling logs and soil survey maps are used to assess
aquifer sensitivity. Sensitivity is based on the permeability of the
overlying material (percent surface organic matter and thickness).
The results are grouped into four classes and represented on maps.
This method evaluates soil attenuation potentials within selected
Wisconsin counties. Attenuation potentials are presented on county
maps at a scale of 1:100,000. Method includes subsurface
geological materials and depth to ground water for the Farmstead
Assessment System.
Five hydrogeologic factors are identified as important parameters in
determining contaminant transport from overlying materials to the
ground water. Each of the five factors are digitized on a computer
and overlaid to produce a composite map.
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Table 3-3. Description of Ground Water Vulnerability Methods
(adapted from EPA, 1993)
Maine of Method
Author(s) and date:
Contact Address
Method Description
Agricultural Pesticides and
Ground Water In North
Carolina: Identification of
the Most Vulnerable Areas
D.H. Moreau, LE. Danielson
(1990)
Water Resources Research
Institute
North Carolina State University
P.O. Box 7912
Raleigh, NC 27696-7912
This aquifer sensitivity method combines DRASTIC with pesticide
use/loading data. Relative vulnerability is categorized as: 1) most
vulnerable; 2) next most vulnerable; 3) next least vulnerable; and 4)
least vulnerable.
CHEMRANK
D.L Nofziger, P.S.C. Rao,
A.G. Hornsby
(1988)
Florida Cooperative Extension
Service
University of Florida
Gainesville, Florida 32611
CHEMRANK is an interactive microcomputer model. It uses four
schemes to screen a group of organic chemicals for their likelihood
to reach ground water. Two of the schemes are based on the rates
at which these chemicals might leach through the unsaturated zone.
The other two schemes use relative chemical mobility and
degradation rates as the basis for the ranking. The two simple
ranking indices/schemes assume that steady water-flow conditions
prevail while the other two use the simulation model, CMLS, to
calculate the time required for the chemical to reach a given soil
depth and the amount of chemical leaching past a Specified soil
depth. The CHEMRANK software Includes data management
features.
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CMLS
D.L. Nofziger, A.G. Hornsby
(1985)
Soil Science Department
University of Florida
Gainesville, Florida 32611
Chemical Movement in Soil (CMLS) calculates the amount of
pesticide leaching past" a 60-cm root zone for any given amount of
time. The model includes graphical displays representing the relative
amount of the chemical remaining in the soil as a function of time.
The model also accounts for soils with 20 layers or horizons, and
enables the user to enter partition coefficients and degradation half-
lives of the chemical of interest for each horizon. The model requires
input of daily rainfall data.
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Table 3-3. Description of Ground Water Vulnerability Methods (continued)
(adapted from EPA, 1993)
Nam<5 of Method
Aulhoi (s) and date:
GLEAMS
W.G. Knisel, R.A. Leonard
(1980)
Contact Address
U.S. Department of Agriculture,
Southeast Watershed Research
Laboratory
Coastal Plain Experimental
Station
P.O. Box 946
Tifton, Georgia 31793
Method Description
This model evaluates the effects of agricultural management
practices on transport of pesticides in the root zone. The model
incorporates rainfall, infiltration, and runoff. The model solves a one
dimensional transient convective-dispersive equation for solute
transport using a simplified water balance. It can also calculate the
movement and transformation of nutrients.
GUS
D.I. Gustatsbn
(1989)
GUSWORK - INC.
P.O. Box 16081
115 Bdlton Place
Chapel Hill, NC 27516
The Ground Water Ubiquity Score (GUS) method calculates a GUS
index. The ground water ubiquity system is a numerical continuum
scale that divides pesticides into non-teachers, transftibnais, and
leachers. A zone Is designated on the GUS scale for each class of
pesticides. The GUS index is based on curve fittings between
pesticide half-lives and K6c values.
Ground Water Contamination
Likelihood!
P.S.C. Rao
(1985)
Department of Agricultural
Engineering
University of Hawaii at Manoa
Honolulu, Hawaii 96822
This method is based on surface soil horizon and pesticide
parameters. The method calculates a continuous numerical index via
a multiplicative exponential model.
Jury's Benchmark Approach
W.A. Jury, W.F. Spencer,
W.J. Farmer
(1983 and 1984)
Department of Soil and
Environmental Sciences
University of California
Riverside, California 92521
This approach uses a series of indices to rank pesticides according
to their potential to volatilize, leach, and degrade in soil. They
presented indices to define convective velocity and diffusion that
incorporate pesticide, hydrogeologic, and climatic factors.
LEAC H Index
D.A. Laskowski, C.A.I. Goring,
P.J. McCall, R.L Swann
(1982);
DOWELANCO
306 Building A2-723
n410Zionsville Road
Indianapolis, IN 46268-1053
This method uses a benchmark approach incorporating the effects of
pesticide solubility and persistence on leaching. It accounts for four
pesticide chemical properties: 1) mass per volume; 2) degradation
half-life; 3) vapor pressure; and 4) sorption coefficient.
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Table 3-3. Description of Ground Water Vulnerability Methods (continued)
(adapted from EPA, 1993)
tyame of Method
Author(s) and date:
Contact Address
Method Description
LEACHM
R.J. Wagenet, J.L Hutson
(1986)
Department of Agronomy
Cornell University
Ithaca, New York 14853
LEACHM is a finite-difference model for simulating the pesticide fate
in the unsaturated zone. The model includes options for Freundlich
sorption and kinetic linear (two-site) sorption, and provides for
simulating transport in soil columns under steady-state and
interrupted steady-state flow. It can simulate the effects of layered
soils, precipitation/evapotranspiration cycles, plant growth, and the
transport of parent pesticides and multiple metabolites. LEACHM is
the only generally available one-dimensional unsaturated zone model
which solves the water balance using Richard's equation. The model
also includes an option for capacity flow. If the appropriate rate
constant is entered, the model can simultaneously predict
concentrations of the parent compounds and metabolites. LEACHM
does not consider the effects of management practices, surface
hydrology, and erosion processes.
Montana Relative Aquifer
Vulnerability Evaluation
(RAVE)
T. DeLuca, P. Johnson
(1990)
Montana Department of
Agriculture
Environmental Management
Division
Helena, Montana 59602-0205
This method consists of a numeric scoring system based on nine
factors. The RAVE score Is intended for on-site determinations.
MOUSE
S. Pacenka
(1984)
Center for Environmental
Research
Cornell University
Ithaca, New York 14853
MOUSE is a set of mathematical models for tracing the transport and
fate of pesticides in the unsaturated and saturated zones. It is used
as a preliminary management tool in different soil-climate-
management regimes. MOUSE has four submodels: 1) climatic data
generator; 2) vadose zone water balancer; 3) vadose zone solute
transporter; and 4) aquifer water and solute transporter.
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Table 3-3. Description of Ground Water Vulnerability Methods (continued)
(adapted from EPA, 1993)
Name of Method
Auflior(s) and date:
OPUS
R.E. Smith, V.A. Ferreira
(1988)
Contact Address
U.S. Department of Agriculture
Northern Plains Area
Ft. Collins, Colorado 80522
Method Description
OPUS consists of a computer simulation model of an agricultural
system. The model simulates relative hydrogeologic erosion and
chemical fate results from various management and climate
scenarios. The objective of this model is to indicate system
response relative to various management practices. OPUS operates
on various time scales and may be used in various types of
agricultural studies. The required inputs include a numerical
description of topography, soils, climate, initial conditions, and
management practices. Processes simulated by OPUS include
hydrology (runoff, soil-water flux and evapotranspiration), erosion,
management, crop growth, and agricultural chemicals. OPUS
generates user specified output.
PATRIOT
J.C. lmhofft P.R. Hummel,
J.W. Kittle, R.F, Carsel
U.S. EPA, Robert S. Kerr,
Environmental Research Lab.
Ada, Oklahoma 74820
PATRIOT is a dynamic modeling system consisting of a combined
flow and transport model (PRZM-2); national-scope data bases for
rainfall, soils geographic occurrence, soil properties, pesticide
properties and cropping practices; data base management; a soil
water retention parameter estimator; and ranking procedures for
comparing leaching potentials for various combinations of geologic
materials to the water table. .
PESTANS I
G.G. Enfietd, R.F. Carsel,
S.Z. Cohen, T. Phan,
D.M. Walters
(1982)
U.S. EPA, Robert S. Kerr,
Environmental Research Lab.
Ada, Oklahoma 74820
PESTANS I is one-dimensional, steady-state model that is limited to
projecting vertical movement through the unsaturated zone. It is
computationally simple to run and is used to evaluate the relative
ground water contamination potential of various pesticides. Although
the model requires very little input data, net recharge velocity may be
difficult to estimate.
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Table 3-3, Description of Ground Water Vulnerability Methods (continued)
(adapted from EPA, 1993)
tyame of Method
Author(s) and date:
Contact Address
Method Description
PESTANS II
G.G. Enfield, R.F. Carsel,
S.Z. Cohen, T. Phan,
D.M. Walters
(1982)
U.S. EPA, Robert S. Kerr,
Environmental Research Lab.
Ada, Oklahoma 74820
PESTANS II is a two-dimensional transient numerical model that
predicts both horizontal and vertical movement of water and
pesticides. This model allows the user to vary degradation rates and
soil absorption with depth. Additional input data on water flux and
soil characteristics in the model allow separate predictions of the rate
of leaching through the root zone and the vadose zone, as well as
calculations of concentrations in the saturated zone. PESTANS II
requires much more hydrogeologic input data, is more complex to
run, and requires considerably more computational time than
PESTANS I.
PRZM
R.F. Carsel, LA. Mulkey,
M.N. Lorber, L.B. Baskin
(1985)
U.S. EPA, Environmental
Research Laboratory
Athens, Georgia 30163
PRZM is a one-dimensional, dynamic, continuous, mechanistic,
pesticide transport model. PRZM requires two input files, one
containing hydrology, crop, pesticide, and soil information, the other
containing daily meteorological data. PRZM has been modified to
include a stochastic (probabilistic) solution. The model provides
concentrations or masses of pesticides expressed in fluxes or in
accumulated quantities leaving a defined depth, respectively.
PRZM-2
J.A. Mullins, R.F. Carsel,
J.E. Scarbrough, A.M. Ivery
(1993)
U.S. EPA, Environmental
Research Laboratory
Athens, Georgia 30163
PRZM-2 is a union of PRZM (see above) and VADOFT. VADOFT is a
one-dimensional, finite-element, flow and transport model. It
simulates the movement of water and chemicals within the soil profile
from the bottom of the root zone to the top of the water table.
Q>
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RZWQM
D.G. DeCdursey, K.W. Rdjas
(1989)
LR. Ahuja, D.G. DeCoursey,
J.D. Hanson, C.S. Hebsom,
R. Nash, K. Rojas, and
M.J.. Shaffer . .
(1992)
U.S. Department of Agriculture
ARS
P.O. Box E
Colorado State University
Fort Collins, Colorado 80522
and
U.S. Department of Agriculture
Durant, Oklahoma 74701
The Root Zone Water Quality Model (RZWQM) Is a physical process
model that simulates the movement of water, nutrients, and
pesticides over and through the root zone at a representative
location within a field. The model simulates the following processes:
physical (hydrology/hydraulics of water and solute transport),
nutrient, pesticide plant growth, management and soil chemistry.
The use of this model has shown the need for a thorough evaluation
of soil properties and their relation to macropore flow.
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Table 3-3. Description of Ground Water Vulnerability Methods (continued)
(adapted from EPA, 1993)
.Name of Method
Author(s) and date:
Contact Address
Method Description
SESOIL
M. Bonazountas, J. Wagner
(1984) and
P. Harrigjin, A. Nold
(1989)
ADL, Inc.
Cambridge, Massachusetts
02140
or
U.S. EPA
Office of Toxic Substances
Washington, D.C. 20460
The Seasonal Soil Compartment (SESOIL) model was developed for
long-term environmental hydrologic, sediment, and pollutant fate
simulations. The physical setting is depicted as four distinct
unsaturated soil layers or compartments, each having uniform
properties. The model simulates the chemical transport and fate
processes of leaching, volatilization, hydrolysis, and biodegradation.
The model can describe water transport, pollutant transport and
transformation, soil quality, pollutant migration to ground water, and
other processes. It can provide the distribution of the chemical in
the soil column which extends from the ground surface to the lower
end of the unsaturated soil layer. The model has been tested and
evaluated.
SPISP
Don Goss
(1991)
Texas A&M University
Blackland Research Center
808 East Blackland Road
Temple, Texas 76502
The Soil/Pesticide Interaction Screening Procedure (SPISP)
categorizes estimated pesticide losses three ways: 1) leached;
2) absorbed runoff; and 3) solution runoff. The model uses
algorithms based on soil properties to group soils into four loss
potentials for leaching and three loss potentials categories for runoff.
In addition, the model uses algorithms based on pesticide properties.
The soil and pesticide groupings are combined in a matrix to give an
overall loss potential: high, intermediate or low. This potential is a
first time evaluation of the impact of using a particular pesticide on a
specified soil.
VIP
J.E. McLean, R.C. Sims,
W.J. Doucette, C.R. Caupp,
W.J. Grenney
(19(18)
Utah Water Research
Laboratory
Utah State University
Logan, Utah 84322
The VIP model involves numerical solution algorithms and
nonequilibrium kinetics to describe the behavior of pesticides in the
unsaturated zone and predict pesticide mass transport to the
atmosphere and ground water.
-------
Table 3-3. Description of Ground Water Vulnerability Methods (continued)
(adapted from EPA, 1993)
tyame of Method
Author(s) and date:
Contact Address
Method Description
VULPEST
J.P. Villeneuve, D. Banton,
P. Lafrance
(1987 and 1990)
University du Quebec Institute
National de la Recherche
P.O. Box 7500
Scientifique Sainte-Foy
Quebec, Canada G1Z4C7
The VULPEST model uses the deterministic adjective dispersion
equation and the Monte Carlo stochastic approach to evaluate
ground water contamination by pesticides. VULPEST has been used
as a management tool to permit the best use of pesticides in
association with a ground water protection scheme. The model
accounts for the characteristics of nonpoint source contamination
and provides a set of probabilistic results. Results obtained from
VULPEST include the maximum concentration, the average annual
concentration and the cumulative mass for each Monte Carlo
simulation. A stochastic breakthrough curve corresponding to the
integration over time of the breakthrough curves is also obtained
from each Monte Carlo simulation. The model is reported as a useful
tool in identifying vulnerable sites and quantifying the type and rate
of pesticide that can be applied to minimize the risk of contamination.
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Chapter 3 ^ ^
3.1.2 Selection of Sensitivity/Vulnerability Assessment Methods
It is beyond the scope of this document to recommend one sensitivity/vulnerability
method over another, or to define selection criteria that would be appropriate for all
situations. The selection of an appropriate aquifer sensitivity or ground water vulnerability
method will depend on a number of implementation, technical, policy, and financial
considerations unique to each State or locality. These factors include:
Ability of the method to accurately assess .aquifer sensitivity;
Applicability of the method to local conditions and available data;
Costs of implementing the method;
Other potential uses or benefits of the information collected;
Status of method development;
Data requirements;
Relative degree of confidence in a particular method (prior validation
or field verification);
Ease of use in applying the method to the conditions of the State;
Level of expertise needed versus available staff;
The degree of technical guidance and data which is available for
more complex methods;
State policies and statutes and the objectives of the aquifer
sensitivity/vulnerability study (e.g., data quality objectives); and
Appropriate spatial scales to use in sensitivity/vulnerability
assessments (e.g., large areas such as counties or fieid-ievel
assessments).
i
For a more detailed discussion of management and technical information to assist States
in selecting aquifer sensitivity or ground water vulnerability assessment methods, see
EPA's Ground Water Protection Division's TAD, A Review of Methods for Assessing
Aquifer Sensitivity and Ground Water Vulnerability to Pesticide Contamination (U.S. EPA,
1993).
Page 3-18
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Chapter 3
3.1.3 Documentation and Evaluation of Sensitivity/Vulnerability Assessment
Methods
This section discusses selected studies and documents that provide technical
information on aquifer sensitivity and ground water assessment methods and on the
evaluations of these methods. Some of the sources referenced in this section are
ongoing and are scheduled to be released in the near future..
EPA's Ground Water Protection Division's TAD, A Review of Methods for Assessing'
Aquifer Sensitivity and Ground Water Vulnerability to Pesticide Contamination (U.S. EPA,
1993) summarizes aquifer sensitivity and vulnerability methods. The purpose of the TAD
is to provide States with the technical information needed to select an appropriate
assessment method. Information for the TAD was assembled from a literature search of
available methods, technical committee meetings, and a workshop.
The Water Science and Technology Board (WSTB) of the National Research
Council convened a committee that evaluated the current techniques for assessing
ground water vulnerability.2 The evaluation results were published in Ground Water
Vulnerability Assessment: Predicting Relative Contamination Potential Under Conditions
of Uncertainty (December 1993). This report summarizes the classes of ground water
assessment methods and provides information on analytical approaches and data
requirements. In addition, the report provides information about factors that contribute
to ground water contamination and has applications in regional ground water
assessments, site specific screening and planning, and also can be used in a variety of
regulatory programs. The report is intended for federal, and State regulatory planning
authorities, consultants, academia, researchers, and public interest groups. The U.S.
EPA, USDA, and the U.S. Bureau of Reclamation sponsored the study and report.
The Phase II Report of the National Survey of Pesticides in Drinking Water Wells,
released, January 1992, provides an assessment of the use of Agricultural DRASTIC.
EPA used DRASTIC to estimate ground water vulnerability to .stratify the Survey. The
Phase II analysis concluded that "DRASTIC did not function effectively when measured
at the county level to predict drinking water wells which may contain pesticides or nitrate."
In addition, subcounty DRASTIC scores showed inconclusive results similar to the county-
level results. The Phase II Report lists several factors that may have affected the ability
of DRASTIC, as it was applied in the Survey, to identify wells containing pesticides. Three
possible causes were noted: (1) DRASTIC was applied to areas the size of counties,
although it was not designed to yield a single numeric vulnerability score for an area of
that size; (2) the level of effort devoted to county-level scoring may have not yielded
sufficiently detailed data upon which to base scoring; and (3) DRASTIC variables may
have been measured on too gross a scale relative to well sites. For more information
2 Further information may be obtained from the Committee on Techniques for
Assessing Ground Water Vulnerability, National Academy of Sciences, 2101 Constitution
Avenue, N.W., Washington, D.C. 20418; Telephone: (202) 334-3422.
Page 3-19
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Chapter 3
refer to the Phase II Report of the National Survey of Pesticides in Drinking Water Wells
(1992).
EPA's Office of Research and Development (ORD) and its Region III office
completed a project to test the performance of the DRASTIC classification system and the
seven DRASTIC elements to predict the occurrence of pesticides and nitrate in shallow
ground waters. In this project, ground water samples were drawn from a large network
of wells located on the Delmarva peninsula, comprised of parts of the States of Delaware,
Maryland, and Virginia. The U.S. Geological Survey (USGS) National Water Quality
Assessment (NAWQA) Study project cooperated in this test.3
In 1990, the U.S. Environmental Protection Agency initiated a pollution prevention
program to explore innovative ideas and new technologies. This project, Prevention of
Ground-Water Contamination from Pesticides: Assessment and Information Tools for
State Use, was a cooperative effort between the Office of Research and Development
(ORD), the Office of Pesticide Programs, and EPA Region 3. The purpose of this project
was to assemble technical tools and information systems that states could use in
developing the Pesticide State Management Plans described in OPP's Pesticides in
Ground Water Strategy. This report presents a summary and analysis of the five
environmental management tools produced by this project. These tools were designed
to be used individually or in conjunction with one another to help state ground-water
resource managers assess the vulnerability of ground water to pesticide contamination.
The five tools that were analyzed are listed below:
(1) Pesticide Assessment Tool for Rating Investigations of Transport
(PATRIOT)
(2) Pesticide Usage Management Planning System (PUMPS)
(3) Delmarva Peninsula Project
(4) Iowa Screening Concepts Project
(5) Pesticide Information Network (PIN)
This report introduces each information product, describes the purpose and s'cope
of each, lists information resources for obtaining full reports and access to software, and
briefly describes the methodology, utility, and limitations of each tool. The report also
3 The U.S. Geological Survey Circular 1080: Are Fertilizers and Pesticides in the
Ground Water? A Case Study of the Delmarva Peninsula. Delaware. Maryland, and
Virginia. U.S. Geological Survey. 1992. provides a non-technical description of the key
findings of the NAWQA study. For more recent information on this study, contact the
Ground Water Protection Section, Drinking Water/Ground water Protection Branch, water
Management Division, U.S. EPA Region 3, 841 Chestnut Building, Philadelphia, PA
10107; Telephone: (215)597-2786.
Page 3-20
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Chapter 3
briefly discusses considerations for using the products in the inter-related steps that make-
up an integrated ground-water vulnerability assessment strategy. Ground-water resource
managers can make use of these tools to design and implement effective and efficient
ground-water assessment and monitoring strategies for protecting ground water from
contamination by pesticides. Copies of the report will be available in September 1994
from EPA's Office of Pesticide Programs; contact Constance Haaser at (703) 305-5458
for further information.
3.2 Pesticide Use Evaluations
Understanding where and how a pesticide is used is central to the development
of an effective pesticide management plan. Both a Generic and a Pesticide SMP should
describe the sources of basic information concerning pesticide usage in the State that
a State plans to use. For a Pesticide SMP, the State also must indicate the sources of
data it has available on the particular pesticide in question, including geographic use,
application rates, application timing, and application method. If data is not available, the
State can describe the method and timetable it is planning to follow to collect such data.
This section describes some of the basic sources of pesticide use and cropping practices
information.4
The 1990 Farm Bill P.L 101-624 1990 established the Agricultural Water Quality
Protection Program as a voluntary incentive program to encourage agricultural producers
in environmentally sensitive areas to develop and implement on-farm water quality
protection and source reduction plans. These agricultural water quality protection plans
should include (as applicable): 1) relevant information concerning the protection of the
water quality of the farm, 2) specific water quality protection goals along with agricultural
and water quality practices that will be avoided or carried out to ensure compliance with
environmental laws, and 3) information to enable the evaluation of the plan and
recommendations of application rates and disposal methods. Under this program, farm
owners and operators enter into three- to five-year agreements with USDA to carry out
the plans. In addition, participants must annually supply production figures, well test
results, soil tests, tissue tests, nutrient application levels, pesticide application levels, and
animal waste usage levels to their USDA Soil Conservation State office. Participating farm
owners and operators must also provide USDA with usage rates on nutrients, pesticides,
and animal waste materials for the three years prior to enrollment in the program.
4 An interagency planning group on pesticide-use data has been in operation since
1981. The planning group is coordinated by EPA and includes representatives of USDA,
the Food and Drug Administration (FDA), U.S. Bureau of Census, and some States. The
group meets several times per year to identity usage data needs and to coordinate
information collection/dissemination efforts. Further information on the interagency
Pesticide Usage Data Planning Group may be obtained from Arnold L. Aspelin, Economic
Analysis Branch, Biological and Economic Analysis Division (7503W), Office of Pesticides
and Toxic Substances, U.S. EPA, 401 M Street, S.W., Washington, D.C. 20460;
Telephone: (703) 308-8136.
Page 3-21
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Chapter 3
3.2.1 Pesticide-Use Profiles Based on Sales or Crop Data
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires EPA to
register pesticides. These federal registrations are accessible using the National Pesticide
Information Retrieval System (NPIRS) data base. Individual State registration data can
also be obtained from NPIRS. A _______^
pesticide listed on NPIRS does not
automatically mean it has a federal
registration.
Estimating for agricultural field use
of pesticides, several techniques are
available based on sales estimates and a
knowledge of regional agronomic
practices. Sales estimates are updated
annually through joint efforts of State
departments of agriculture, the USDA
Economic Research Service (ERS), and
the USDA National Agricultural Statistics
Service (NASS). MASS also maintains
State statisticians who provide State-level
and sometimes county-level information
on agricultural production. The spatial
resolution of this information is variable,
however, and may not be sufficient for
reliable ground water vulnerability
determinations in some areas.
The pesticide-use approach utilized by
Gianessi and Puffer {1990} included an
equation of the following form:
Pesticide use (pounds of active
ingredients) = A x B x C, where
A = Harvested acres planted of specific
crops,
B = Percent (as a fraction) of harvested
acres receiving, pesticide
applications each year, and
C = Typical application rate (pounds of
active ingredient/acre/year).
Ah example of applying such
estimation techniques for counties within
the State of North Carolina is provided in
Moreau and Danielson (1990). The
National Oceanic and Atmospheric
Administration has also used such
estimation techniques for 78 estuarine
drainage areas rimming the contiguous
United States (Piat et al., 1989),
The USDA Agricultural Research
Service (ARS) and Cooperative Extension
Service, in conjunction with researchers
at State land grant universities and State
cooperative extension services, are good
sources of information on regional agronomic practices. These groups make
recommendations to farmer-operators on pesticide application rates and techniques for
most common crops. Such recommendations are generally published in a variety of
technical bulletins, or in more general interest publications for distribution to the user
community (USDA Water Quality Initiative Team, 1990). County agricultural extension
agents are familiar with local cropping practices and the recommended pesticide usage
for their localities.
Studies conducted by the National Center for Food and Agricultural Policy
(formerly Resources for the Future) (Gianessi, 1986; and Gianessi. and Puffer, 1988,1990,
and 1991) combined production and agronomic information to assemble a national-level
data base of estimated agricultural pesticide use, turf pesticide use (i.e., golf courses),
urban use, as well as estimates of herbicide use.
Page 3-22
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Chapter 3
The level of spatial resolution using pesticide use profiles based on sales or crop
data depends on the reliability of production statistics and agronomic information."
Production statistics generally result in State-level estimates. As the spatial resolution
moves down to the county level, production statistics are generally based on a small
number of data collection points within each county. Where the types of crops grown are
highly uniform (e.g., winter wheat in Kansas), the county-level figures.may be adequate
for determining ground water vulnerability. Where a county shows a diversity of crops
and cropping systems, county-level production figures should be used with greater
caution.
States seeking detailed spatial production statistics may be able to obtain records
down to the individual farmer-operator level. The USDA Soil Conservation Service (SCS)
and Agricultural Stabilization and Conservation Service (ASCS) sometime track land uses
down to the farmer-operator level in response to requirements under the 1985 Food
Security Act (usually called the Farm Bill). The ASCS, which disburses a variety of
commodity support payments, maintains detailed data on a limited number of crops
grown by farmer-operators in some areas. The SCS and ASCS use these detailed data
sources to generate summaries at county or State levels. The main limitation on the
availability of detailed data (in addition to laws regarding individual landowner
confidentiality) may be the extent to which farmers in a region participate in Farm Bill
commodity programs. There are no commodity supports for many types of crops, and
therefore the data collected by SCS and ASCS may be sparse in some areas.
The SCS and ASCS maintain local offices that work closely with State organizations
such as soil and water conservation districts and county extension offices. In addition,
State departments of agriculture often have district or regional field inspectors who
provide valuable insights based on their best professional judgment (BPJ). Where not
accompanied by organized survey or official recordkeeping procedures, these BPJ
approaches are best viewed as an indirect approach. However, they remain a good
means of supplementing the more readily available published information or to make
estimates of pesticide use at the sub-county level.
3.2.2 Voluntary User Surveys
Select pesticide use data are available from pesticide user surveys. The USDA's
ERS/NASS began a major pesticide usage data collection program in 1990 as part of the
President's Water Quality Initiative and '
Food Safety Initiative. Under this
program MASS, in conjunction with State
departments of agriculture, annually
survey farmers to gather pesticide usage
data for select field crops, fruits,
vegetables, and nuts. USDA published a
1990 Field Crop Summary (March 1991) _,,...,«
and a Vegetable Summary (June 1991) Board of Pesticides C-1990)-
Each summary includes crop data on the
in 1984, the State of Maine began a
program of surveying pesticide use. The
State updates the survey annually. The
goal is to build county pesticide use
profiles and describe application methods
and cropping practices in Maine (Maine
Page 3-23
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Chapter 3
quantities of pesticides applied, application rates, and application frequency for the major
producing States. For the most part, the pesticide data collected are reliable for estimate
State level usage. Depending upon funding, USDA plans to continue these annual
voluntary pesticide usage data surveys and expand the survey to include more crops and
cover a greater production area.
In recent years, the USDA National Agricultural Pesticide Impact Assessment
Program (NAPIAP) has given States grants to conduct pesticide-use and benefits studies.
Chapter 7 provides contact information for NAPIAP State liaisons.
3.2.3 Commercial Pesticide Usage Surveys
A wide range of agricultural and nonagricultural pesticide-use data are available
for a fee from commercial market research organizations. A number of firms regularly
conduct pesticide-use surveys either on a multi-client subscription basis or for hire on a
proprietary bases. Such services are often utilized by major pesticide producing and vary
greatly in survey approach, sites covered, geographic specificity, statistical validity, and
various details of actual pesticide-use. Commercial survey firms also conduct studies on
a custom basis to meet client needs. In the case of custom/proprietary studies, the
results are generally only available to the sponsoring organization. Table 3-4 provides
information on some commercial market survey organizations. Mention of. these
organizations does not constitute their endorsement by the United States government.
Table 3-4. Examples of Information Available from
Some Commercial Market Survey Organizations
Organization
Kline and Company, Inc.
Fairfield, New Jersey
Maritz Marketing Research Inc.
Fenton, Missouri
Doane Agricultural Services
St. Louis, Missouri
Technomic Inc.
Chicago, Illinois
National Center for Food and Agricultural
Policy
Washington, D.C.
Type of Data
Commercial and Professional Markets for Pesticides
and Fertilizers
Specialty Crop Study Pesticide Use Study
Tillage and Cultural Practices
Ornamentals, Sugar Beets, Biotechnology,
Control -:
and Pest
Insecticide and Fungicide Data Bases
Page 3-24
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Chapter 3
3.2.4 Required Recordkeeping
EPA certification regulations require that all commercial certified applicators
maintain pesticide-use records for restricted-use pesticides. Some States have
promulgated more comprehensive regulations, adding reporting requirements,
recordkeeping requirements for general-use pesticides, and recordkeeping requirements
for private certified applicators.
In some cases, records, required for restricted-use pesticides support SMP
assessment and planning. The 1990 Farm Bill includes a provision requiring
documentation of the use of restricted-use pesticides. These records may be
comparable to those already maintained by commercial certified applicators in each State.
Under this provision, each farmer who applies restricted-use pesticides must maintain
records of their use. Federal agencies may obtain access to restricted-use pesticide
records through the USDA. State agencies may obtain access to these records through
the State lead agency for pesticides. (7 U.S.C.A. §136i-1(b))
Many States require pesticide recordkeeping at the point-of-sale or for end users.
These records may include a broad range of data. Table 3-5 provides information on the
recordkeeping requirements for certified applicators of restricted-use pesticides in 43
States. A more detailed summary of California's recordkeeping requirements is provided
in Table 3-6.
3.2.5 Nonagricultural Use Considerations
Because pesticides are also used for nonagricultural purposes, SMPs should
explain how information on the extent and types of such uses will be obtained. Some or
all of the following nonagricultural uses of pesticides (U.S. EPA, 1987) should be
considered. The types of uses each State considers will depend on its unique
characteristics. These uses include: .
Ornamental lawns and turf (e.g., golf courses); .
Ornamental shrubs and vines;
Right of way maintenance;
Pest control for household, domestic, and institutional dwellings and
industrial sites;
Processed nonfood products, such as textiles and paper; and
Aquatic sites, including canals and lakes.
Page 3-25
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Table 3-5. Recordkeeplng Requirements for Certified Applicators of Restricted Use Pesticides*
Mtate
Alasfa
Arize**
Arkansas
Gallfoflila
Goto: ado
. " Conrectteul
Delaware
Florid i
Hawal
IWnoli
India la
*|OWO
Kenan
Kemuohy
Malm:
Marylnd
Mass ichusims
Product
Nam*
-
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Fom-iu-
Mton
/
J
-
/
-
/
-
/
-
-
- '
/
-
-
/ '
-
CPA
Reg.
No.
/
/
/
/
/
-
-
/
/
/
-
-
-
-
-
/
Afitount
Applied
-
/
/
/
/
-
/
/
-
/
/
/
-
/
/
/
RMe
Applied
-
/
-
/
-
/
/
-
/
-
/
/
-
/
/
'
Location
/
/
/
/
/
/
/
/
/
/
f
-
-
/
/
/
Treated
Area
-
/
/
-
/
-
-
/
-
/
-
-
-
/
- .
-
Target
Pert
/
-
/
/
/
-
/
-
/
.-
/
-
/
/
/
Crop or
Stored
Product
/
/
/
/
/
-
/
-
-
/
-
-
-
-
/
/
Method
Applied
-
/
-
-
-
-
/
-
*
-
-
-
/
/
/
Date
Applied
/
/
/
/
/
/
/
/
/
/
/
J
-
/
/
/
Applicator
Nairn/
Addreta
/
/
-
/
-
/
/
-
/
-
/
/
y
-
/
/
/
Applicator
Can No.
-
/
-
'
/
-
-
/
-
/
/
/
-
-
-
-
Recording
Deadline
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Record
Retention
/
/
/
-
5 years
/
/
/
/
/
3 years
-
-
-
2 years
3 years
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DariveO horn iiurvey conducted by the State u» Maryland In 1990. State* Not Responding: Alabama, Georgia, Idaho, Louisiana, Mississippi, Nebraska, New Yoifc, Vermont, District of Columbia, and ttw Virgin Islands.
" Requirement* for Commercial Rsttrtcted-Uss PjttteWe applicators only.
-------
Table 3-5. Recordkeeplng Requirements for Certified Applicators of Restricted Use Pesticides* (continued)
Stitt
Michigan
Minnesota
Missouri
Montana
Nevada
" New Hampshire
New Jersey
New Mexico
North Carolina
North Dakota
"Ohto
Oklahoma
Oregon
Pennsylvania-
Puerto Rico
Rhode Island
South Carolina
Product
Name
/
/
Formu-
lation
/
/
EPA
Reg.
No.
-
/
Amount
Applied
/
/
Rat*
Applied
/
-
Location
/
/
Treated
Area
-
/
Target
Pett
/
-
Crop or
Stored
Product
-
-
Method
Applied
/
-
Date
Applied
/
/
Applicator
Name/
Addrma
-
/
Applicator
Cvft. No.
-
/
Recording
Deadline
-
Day Applte.
Record
Retention
3 years
5 years
Operational recordkeaplng requirements lor certified commercial or noncommercial applicators not specified for this State.
/
/
/
/
/
/
/
/
/
/
/
/
/
. -
/
/
/
/
/
-
f
/
/
/
/
/
-
urHMttnnlftv
/
-
-
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/
-
-
/
-
-
-
-
-
-
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/
-
/
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/
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/
-
/
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-
/
-
/
/
/
/
/
/
-
-
-
/
/
/
/
/
/
/
/
/
/
J
/
-
-
/
-
/
/
-
/
/
-
-
-
-
-
-
-
/
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/
/
/
-
/
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-
-
-
-
-
/
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-
-
/
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-
-
-
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-
-
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-
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-
-
/
/
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/
/
/
/
/
/
/
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/
/
-
/
/
/
-
/
-
/
/
/
Name Only
Name Only
-
/
-
-
-
-
-
-
-
/
-
-
-
/
-
/
-
24 hours
-
7 days
-
-
-
Day Appllc.
Day Applic.
-
-
-
-
-
-
2 years
2 years
2 years
2 years
2 years
3 years
-
3 years
2 years
3 years
3 years
2 years
2 years
-
0*ttv«d from turviy conducted by th* SW* of Muyttnd In 1990. StitM Not Responding: Alabama, Georgia. Idaho, LouMana. Mississippi, Nebraska, New York, Vermont. District of Columbia, and the Virgin Islands.
Requirements tor Commercial Restricted-Use Pesticide applicators only.
North Carolina has requirements for commercial aerial applicators (all pesticides) and commercial ground applicators (restricted use pesticides only). No requirement exists lor certified private applicators to keep records.
TJ
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-------
TJ
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Table 3-5. Recordkeeplng Requirements for Certified Applicators of Restricted Use Pesticides* (continued)
Stlte
SouthHtakola
"Tenrtesiee
Texas
"Utah
Virginia
Washington
West Vljglnla
VWscoreim
Wyorrtnfi
Product
Nimo
/
/
/
/
/
/
/
/
/
Formu-
lation
/
-
/
/
-
-
/
/
/
EPA
Re8.
No.
-
-
/
-
/
/
-
/
/
Amount
Applied
/
/
/
/
/
/
/
/
/
Rtt»
ApplM
-
/
/
/
/
/
/
/
/
LocMlon
/
/
/
/
/
/
/
/
/
Trailed
Area
/
-
/
-
/
/
-
/
-
Target
Pest
/
/
/
-
/
/
/
/
/
Crop or
Stored
Product
/
/
/
-
/
/
-
/
/
Method
Applied
/
-
/
-
/
/
-
/
-
Date
Applied
/
/
/
/
/
/
/
/
/
Applicator
Name/
Addreaa
/
/
-
. -
/
/ .
Name Only
Name Only
-
Applicator
Cert No.
-
-
-
-
/
/
-
-
-
Recording
Deadline
-
-
-
-
-
-
-
-
-
Record
Retention
-
2 years
- .
2 years
2 years
7 years
-
2 years
-
Dwtv*d horn tuiv«y conducted by ttw SIM* ol Mcuylmnd In 1990 Stain Not Rmpondlng: Alabama. Qoorgla, Idaho, Louisiana, Mlsslulppl, Nabratka, New York, Vermont, District of Columbia, and tho Virgin lilands.
Rcqulnmiants fcr Commtrcla) RMtrictad-Ua* Putddda applicators only.
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-------
Table 3-6. Summary of Required Pesticide Sale and Use Recordkeeping In California
Recordkeeping Required for
Licensed Pesticide Dealers
Pesticide Users
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Records Maintained on
Pesticides Sold/Delivered
Records submitted by
purchasers
Restricted-use pesticides
Known leachers
* Pesticides used for agriculture,
rights-of-way, golf courses,
cemeteries
Restricted-use pesticides
Industrial post-harvest
commodity pesticide use
* Pest control businesses
Suspected leachers used for
outdoor industrial or institutional
treatment
Record Content
Name and address of purchaser
Quantity and type purchased
Agricultural Pest Control Adviser
recommendation
Delivery location
Person/business receiving
shipment
Signed statement, permits
Certified applicator number
Application date and amount
applied
Operator name
Location of use
Crop or site treated
Size of treated area
Pesticide name and registration
number
Additional requirements for
agricultural property operators and
agricultural pest control
businesses:
Treated ideation (county,
township, range, section, base
meridian)
* Hour treatment completed
Operator and site identification
numbers
Name of application supervisor
Exclusions
Home use
None
Livestock
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Table 3-6. Summary of Required Pesticide Sale and Use Recordkeeping In California
(continued)
Recordkeeping Required for
Property Operators
Agricultural Pest Control Advisors
Records Maintained on
Pesticide applications where re-
entry intervals exceed "spray is
dry/dust is settled" requirement
Ground water protection
advisories
Record Content
Crop and acreage
Pesticides used
Dosage, dilution rate, and
volume per acre
Date application completed
Operator of treated property
Address of operator
Treated property location (base
meridian, township, range,
section) :'::;;. :'.-.'. v^: "
Soil textural class of treated
property
Property rriafi indicating such
features as active and
abandoned wells (domestic,
irrigation, drainage)
Treatment conditions that will
minimize potential for ground
water contamination
Signature and address of Pest
Control Advisor
Exclusions
O
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1
CO
None
None
-------
Table 3-6. Summary of Required Pesticide Sale and Use Recordkeeping in California
(continued)
Recordkeeping Required for
Records Maintained on
Record Content
Exclusions
Agricultural Pest Control Advisors
(continued)
Written Recommendations
Pesticide name, dose, and
recommended application
method
Pest to be controlled
Owner/operator, location, and
acreage of treated site
Crop, commodity, or site
Application schedule or
conditions
Warning of potential damages
Signature, address, date, and
affiliation of person making
recommendation
Worker re-entry interval, if
established
Label restrictions on use of
disposition of treated commodity
or area
Criteria for determining the need
for treatment
None
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Table 3-6. Summary of Required Pesticide Sale and Use Recordkeeping In California
(continued)
Reoordkeeping Required for
Agricultural Pest Control Businesses
Agricultural Property Operators
Records Maintained oh
Pesticide Applications1
Pesticide Applications2
Record Content
Name of property owner/operator
Property location
Date and time of notification
Notification method and person
notified
* Property jocatibri, site
identification number, and
; 'acreage' ..-.;.;,;.':-'.';--.; '
i Pesticides applied :
Date and time application
completed
Applicable re-entry intervals
Exclusions
None
fte-entry Intervals
excluded If
operator received
written
recommendation
from Pest Control
Advisor
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1 Reported to property owner/operator within 24 hours of application completion.
2 Maintain records of pesticide application notices by site treated.
-------
Chapter 3
A range of recdrdkeeping requirements Is illustrated by the different system in use in two
States: ..-. /- -,. - : ".: .,-."-' ;";. V .., '''.
California's system of Pesticide Management Zones (PMZs) allows the continued use
of pesticides with the potential to pollute ground water within specified areas provided
the use is subject to strict safeguards. These safeguards Indude detailed
recordkeeping by pesticide dealers (who are required to obtain signed statements from
purchasers of certain restricted-use pesticides that have been fpund in ground water
(i.e., known leachers)). These statements indicate whether ;the materials will be used
within a PMZ. Dealers must verify that the purchaser has the required permits and must
submit quarterly sales reports for :ail uses of known leachers to thei California
Department of Pesticide Regulation (CDPR). The end user must have a permit to use
those restricted use pesticides within a PMZ. A certified applicator (commercial or
private) is required to apply known leachers both in$ide and outside PMZs. Farmer-
operators as well as licensed applicators are required to maintain records of their
pesticide use. Table 3-6 summarizes the pesticide sale and use recordkeeping
requirements that relate to minimizing the potential for ground water contamination in
California.
Maine's SMP approach includes a system of Limited Use pesticides. Once a pesticide
is classified as Limited Use, the sale and use is restricted to licensed persons with a
permit granted by the State's Board of Pesticide Control (BPC). To obtain a permit,
applicants are required to provide BPC with the following information for each pesticide:
- Name of applicator and/or landowner; ;
- Description of soils; -: >
- Map of use area noting locations of surface waterbodies, springs, and bedrock or
ledge protrusions;
- Rate, timing, and methods of application; and :
- Description of current or proposed wellhead setback or other ground water
protection measures. -.. : ; : -
In 1989, Maine initiated requirements for point-of-sale recordkeeping for all general-use
pesticides (Maine Board of Pesticides Control, 1990). In conjunction with existing
requirements for restricted-use pesticides, this requirement helps in generating actual
quantity of use data for Maine's current list of approximately 5,200 registered pesticides.
Although these sales reporting procedures do not necessarily identify the areas whe,re
the products are used, the data provides checkpoints to compare end-user surveys and
estimates based on indirect techniques. Requiring some recordkeeping for general-use
pesticides makes it easier to estimate pesticide use in urban areas for homes and golf
courses. '. .
Page 3-33
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Chapter 3
EPA has a program of conducting pesticide usage surveys for the urban/nonfarm
sectors. The survey results provide national and some regional information on the
products used, use practices, disposal methods, and other related information. The
survey was not designed to provide estimates at State and county levels, but provides
background information useful in helping address home/garden usage related to ground
water concerns. EPA has conducted surveys of other urban/nonfarm sites in the past
(e.g., golf courses and pest control operations). In the future, EPA will continue
conducting annual surveys of certified applicators involved in nonagricultural pest control.
The initial survey results, published in 1993, include estimates of pesticides used, rates,
and use sites. .
Homeowners and golf courses constitute significant categories of pesticide use.
Suburban living styles commonly feature large grassy lawns highlighted by horticultural
landscaping with shrubs and flowering plants. Maintaining such landscapes generally
involves the use of fertilizers and pesticides. Residential structures are also major users
of pesticides for termite control. Many of the problems associated with urban uses
involve improper disposal of remnant quantities of pesticides or unintentional misuse.
EPA's Office of Pesticide Programs conducted a national survey of home and garden use
of pesticides in August and September, 1990. Information was collected on household
use, storage, and disposal of pesticide products and containers.5
Some States require point-of-sale records on general pesticides largely to
assemble overall estimates of pesticides likely used for homes and golf courses (Maine
Board of Pesticides Control, 1990). Where restricted-use pesticides that require the
services of custom applicators are involved, State applicator certification programs and
other oversight measures provide indirect means of estimating the types of pesticides
used in urban or suburban settings.
3.3 Geographic Information Systems
Geographic information systems (GIS) provide a computer-based method of
storing, retrieving, analyzing, and displaying geographic and nongeographic data. A GIS
is comprised of hardware and software that allows the use of data layering from a variety
of existing sources. These sources include aerial photographs, topographic maps, land
use and zoning maps, satellite images, and field notes. For example, a GIS can store the
locations of specific pesticide application areas and vulnerable ground water sources and
use this data to identify their geographic locations on a map.
5 For further information and the conduct and results of this survey, contact the Office
of Pesticide Programs, Biological and Economic Analysis Branch; Telephone:
(703) 308-8050.
Page 3-34
-------
Chapter 3
A number of State agencies have used GIS data bases to solve environmental
management problems. For a majority of States, natural resource management and
environmental planning have formed the primary applications for GIS technology
(Warnecke, 1990).
Two pilot projects are underway in Jefferson County, West Virginia and Lancaster County,
Pennsylvania, to demonstrate the use of GIS in the development of SMPs. EPA's Region III and
an interagency group of federal, State, and local agencies are cooperating to address
environmental, agricultural, and health issues. The report on the Jefferson County project, titled
Use of GIS to Determine Ground Water Vulnerability to Contamination by Agricultural
Chemicals: Jefferson County, West Virginia Pilot Study,' is scheduled for completion by the
: Spring of 1994; the Lancaster County Pilot Study of Pequea and Mill Creek Watersheds is
scheduled for completion in 1995. In both projects, farmers supplied data on pesticide usage
and drinking water wells through EPA-sponsored interviews. USDA provided hydrogeologic
information, including a water table elevation map and information on ground water flow; and
the West Virginia Department of Natural Resources and Monsanto contributed a ground water
vulnerability map. Spatial analyses include: evaluations of pesticide use with respect to the
locations of permeable soils and vulnerable ground water, evaluations of at risk wells from: 1)
pesticide applications; 2) point source contamination from pesticide handling, storage, and
disposal techniques; and 3) comparisons of use information from various sources.
The Rhode Island Department of Environmental Management and the University of Rhode
Island have developed the Rhode Island Geographic Information System (RIGIS) to assist in the
development of a ground water protection program (Baker et aL, 1990). Applications include
developing a State ground water classification system, delineating wellhead protection areas
via the integration of RIGIS with ground water flow models, providing ground water information
to local governments, and developing cartographic products. ., .
Michigan used GIS to produce a generalized map of aquifer vulnerability to surface
contamination in Michigan. Using a 1980 version as a base map, soil permeability data (from
USDA/SCS STATSGO) were overlaid on aquifer sensitivity information that was derived from well
records.
In New York, the Suffolk County Water Authority (SCWA) used GIS data bases to design a
wellhead protection strategy to protect drinking water supplies from potential contamination
caused by urbanization and over fertilization of agricultural lands (Scott, 1990). By integrating
GIS with ground water flow and transport equations, SCWA developed a method of determining
the zone of contribution (the area around the well that contributes water) for county wells.
Three zones were delineated based on various hydrogeologic factors, including radius about
the well, pumping rate, aquifer permeability and thickness, duration of pumping, and direction
and velocity of ground water flow. >
in California, the San Joaquin Valley Drainage Program identifies and addresses problems
associated with the drainage of agricultural lands in the San Joaquin Valley (Hansen, 1990).
This program involves the coordination of programs managed by the both State and federal
agencies. The objectives of the program are to maintain the agricultural productivity of the area,
to restore the viability of the areas's fish and wildlife, and to identity areas of affected water
quality and public health from drainage of agricultural land. The basic task of the program
involves the establishment of a spatial data base containing all information held or developed
by the program. :
Page 3-35
-------
Chapter 3
GIS can also perform data base management functions. Because data about a
geographic area may change with time (e.g., pesticide use, agricultural practices, and
water use), data layers may require frequent updating. GIS allows data already existing
in the system to be updated (i.e., modified or deleted) as conditions change.
The remainder of this section discusses considerations for developing a GIS, how
GIS can be used to develop and implement SMPs, and concludes with several examples
of how several States implemented GIS, thus enhancing their water resource protection
efforts.
3.3.1 Advantages for SMP Development and Implementation
GIS technology can be an integral part of a strategy to prevent, monitor, and
respond to pesticide contamination in ground water. For example, a spatial data base
that contains data on current and past pesticide use and vulnerable drinking water areas
can be used by States to assess pesticide contamination risks and potential impacts on
drinking water and display geographic areas at risk. States can incorporate GIS
technology into their SMPs in several ways. These include:
Identifying areas that are sensitive or vulnerable to pesticide
contamination by overlaying data on hydrogeologic and
pesticide-use characteristics (GIS technicians should not mix data
that represents different map sources);
Cataloguing drinking-water well locations, pesticide mixing, loading,
and storage locations, pesticide detections and concentration levels,
geographic distribution of agricultural practices, and pesticide use
information;
Integrating GIS technology with flow and transport models to predict
time-dependent concentration distributions for geographic areas;
Analyzing spatial and temporal changes in water quality;
Generating what-if scenarios and analyzing impacts of changing
management practices;
Planning geographic areas included in response implementation
measures; and
Providing communication materials (e.g., maps) for public outreach.
Page 3-36
-------
Chapter 3
3.3.2 Implementation Considerations
State agencies that are planning to implement GIS should consider the following
factors:6
Cost. The cost of setting up a GIS system may range from $10,000
for a simple PC-based system to several hundred thousand dollars
for a multi-user workstation system. The system cost will depend on
the hardware and software required to support the GIS needs. A
system may include input devices (e.g., terminal, scanners,
digitizers), data storage (e.g., stand alone disk drives, tape drives),
output devices (e.g., plotters, visual monitors), and a variety of
software packages (e.g., data base management, statistical analysis,
modelling, mapping). To reduce the costs of developing a GIS and
thus avoid duplicating existing efforts, States should consider
enhancing existing systems to support the implementation of their
SMPs.
A DRASTIC map of Nebraska, using commercially available GIS software, was
completed in about one year by student employees at a cost of about $66,000. Data were
collected for all 7 DRASTIC parameters for the whole State, digitized, and mapped to yield
a complete State index map with a 1:1,000,000 scale. Ttie project also prepared a
comprehensive flow chart illustrating the process. (Rundquist, et al. 1991) Contact:
Nebraska Department of Environmental Quality, Ground Water Section, Lincoln, Nebraska;
Telephone: (402)471-0096.
Data Availability and Data Integrity. Many organizations at federal,
State, and local levels have GIS capabilities including data and
information which, if shared, can save resources and time. Data on
soil types, pesticide use, ground water, and weather, for example,
are of interest to a number of programs, and exchange of such data
is encouraged. The source of the data layers that are used to build
the GIS data base may not be in a format that is recognized by the
GIS technology. Consequently, additional time, hardware, and/or
software may be required to translate the data into a suitable format.
In addition, the quality of spatial analyses afforded by GIS is only as
good as the quality of the data layers available for input into the
system. Further, some data entry practices, such as entering data
that are compiled at different scales, may limit the usefulness of the
6 Under the Pollution Prevention Initiative, EPA's Office of Research and Development
is developing guidance for States to use in selecting and implementing GIS. Information
sources are provided in Chapter 7.
Page 3-37
-------
Chapter 3
data. The costs associated purchasing and/or entering data may
significantly increase the capital outlay for a GIS.
Functionality and Ease of Use. The intended use of a GIS is an
important criteria for selecting the hardware and software that will
make up the system. Therefore, the specific functions that the GIS
is to perform must be clearly identified prior to purchasing the
GIS-related hardware or software. In addition, the ease of use of the
system should also be considered. The complexity of the system
and the availability of "easy-to-understand" user documentation will
influence the amount of user training. If extensive training is
required, the cost of the system could increase significantly (Sham,
1990).
Personnel. The personnel functions necessary to support a GIS
include data input (e.g., keyboard operators, scanner operators),
data management (e.g., programmers, statistical analysts), data
storage (e.g., computer operators), and data output (e.g., plotter
operators). The level of experience and technical training required
to develop a GIS will directly affect the cost of the system.
3.4 Defining Reasonably Expected Uses of Ground Water
The Final Comprehensive State Ground Water Protection Program Guidance (Final
CSGWPP Guidance) describes an interactive process for defining reasonably expected
uses of drinking water that will afford States greater attention to uses which have
particular value or benefit through a differential management approach. These uses may
include ecological support and drinking water, as well as other purposes. States may
also want to consider other principal uses and factors, such as for agriculture and
industry. It is left to the States to determine relative priorities among the uses. For SMPs,
however, the protection of currently and reasonably expected sources of drinking water >
both public and private, is a required priority.
The approach described below, as adopted from the Final CSGWPP Guidance,
allows each State to tailor resource based priority-setting to its own institutions. First, a
public process is described for defining the reasonably expected uses of ground water.
Second: factors are identified for States to consider in defining ground waters reasonably
expected to be used for ecological purposes and drinking water. Third, an EPA default
definition for Federal program purposes will be applied to the extent needed to implement
regulatory programs in States choosing not to define these uses. This approach is
described below.
Page 3-38
-------
Chapter 3
3.4.1 Public Process
To obtain the operational flexibility through the CSGWPP, the State's public
process to determine reasonably expected uses should (a) maximize public input, and
(b) have its results consistently applied across programs.
The State should utilize a public participation process with objectives
as defined in 40 CFR Part 25. State laws designating ground water
uses are considered adequate for this purpose. States are
encouraged to keep their ground water use designations current.
The objectives of 40 CFR Part 25 are to:
Ensure that the public has the opportunity to understand
official programs and proposed actions;
Ensure that the government decision defining reasonably
expected uses includes consulting interested and affected
segments of the public;
Ensure that the government action is as responsive as
possible to public concerns;
Encourage public involvement in implementing environmental
laws;
Keep the public informed about significant issues and
proposed project or program changes as they arise;
Foster a spirit of openness and mutual trust among EPA,
States, sub-state agencies, and the public; and
Use all feasible means to create opportunities for public
participation and to stimulate and support participation.
The State should consistently apply its definitions of ground water
uses across all prevention and remediation decisions over which the '
State has control. For example, (i) the State should use a consistent '
definition regardless of waste type (e.g., sewage sludge or municipal
solid waste) in determining facility requirements, and (ii) a State's
definition would apply similarly to State and Federally funded
remediation. As another example, application of a State's definition,
which would require remediation programs to create an "island of
clean" within a larger region of previously contaminated ground
water, could be considered an inconsistent application.
Page 3-39
-------
Chapter 3
3.4.2 Defining Reasonably Expected Uses for Ecological Support and Drinking
Water
While States are expected to consider all uses, this section focuses on support of
ecological systems and drinking water, because most laws that EPA implements focus
on human health and the environment.
For Ground Water Supporting Surface Water Ecosystems: EPA's
1991 Ground Water Protection Strategy emphasizes protection of
ground water closely hydrologically connected to surface waters to
ensure ecosystem integrity. EPA considers the following factors
important indicators of ground water hydrologically connected to
surface water. :.A State may choose to use other factors. States
should negotiate with the EPA Regions which factors are most
appropriate for their respective circumstances.
Relative ground water travel time from potential contaminant
sources;
Relative contribution of ground water to quantity and quality
(chemical and physical) of surface water;
Biota living in or dependent on ground water/surface water
ecosystems;
Climatic or seasonal variations; and
Attainment of water quality standards to support designated
use of surface water.
For A Reasonably Expected Source of Drinking Water: EPA
considers the following factors to be important in evaluating the
future use of ground water. EPA expects States to consider or
dismiss, with a sound rationale, from consideration these factors
when determining a reasonably expected drinking water source. The
State may also use other factors. States should negotiate with EPA '
Regions which factors are most relevant to their respective '
circumstances.
Hydrologic characteristics, including water quality and
quantity;
Availability and cost of alternative water supplies;
Demographics, including future growth and population
patterns;
Page 3-40
-------
Chapter 3
Remoteness from likely areas, of residential or other
development;
Land use planning;
Remediation technology for, and practicality of, remediation;
Cost of prevention and remediation; and
Inter-jurisdictional considerations (Tribes, federal government,
other States).
3.4.3 EPA's Definition of "Reasonably Expected Uses of Ground Water"
In the absence of State definitions, EPA's definitions of "Ground Water Supporting
Surface Water Ecosystems" and "A Reasonably Expected Source of Drinking Water" will
apply.
Ground Water Supporting Surface Water Ecosystems: EPA's
definition for ground water closely hydrologically connected to
surface water and supporting its ecosystems is ground water which,
if its availability or quality are affected, would result in surface water
not meeting the water quality standards required to support its
designated use. (This definition reflects the current state of
information on ground water - surface water interaction. This
definition may change as more information becomes available.)
A Reasonably Expected Source of Drinking Water: EPA's
definition for a reasonably expected source of drinking water is
ground water that is available in sufficient quantity for its intended
use and contains fewer than 10,000 mg/l total dissolved solids. This
definition derives from the Safe Drinking Water Act, Part C -
Protection of Underground Sources of Drinking Water, Section 1421.
EPA has developed this definition to be as protective as possible of
future ground water uses; however, EPA recognizes that this
definition may be more comprehensive than a State may wish to be.
i
3.5 References
Aller, L, T. Bennett, J.H. Lehr, R.J. Petty, and G. Hackett. 1987. DRASTIC: A
Standardized System for Evaluating Ground Water Pollution Potential Using
Hvdroqeoloaic Settings. National Water Well Association. 455 pp. PB87-213914.
Baker, C.P., E.G. Panciera, and P.V. August 1990. "Groundwater Protection and the
Rhode Island Geographic Information System." Proceedings of the Tenth Annual ESRI
User Conference. V. 1.
Page 3-41
-------
Chapter 3
Berg, Richard C., and John P. Kempton. 1987. Stack-unit Mapping of Geological
Materials in Illinois to Depth of 15 Meters. Illinois State Geological Survey Circular 542.
Berg, Richard C., John P. Kempton, and Keros Cartwright. 1984. Potential, for
Contamination of Shallow Aquifers in Illinois. Illinois State Geological Survey Circular 532.
Carsel, R.F., LA. Mulkey, M.N. Lorber, and LB. Baskin. 1985. 'The Pesticide Root Zone
Model (PR2M): A Procedure for Evaluating Pesticide Leaching Threats to Ground Water."
Ecological Modeling 30:40-69.
Chen, H.H., and A.D. Druliner. 1987. Nonpoint Source Agricultural Chemicals in Ground
Water in Nebraska-Preliminary Results for Six Areas of the High Plains Aquifer. USGS
Water-Resources Investigations Report 86-4338.
Cohen, D.B., C. Fisher, and M. Reid. 1986. "Ground Water Contamination by Toxic
Substances: A California Assessment." In Evaluation of Pesticides in Ground Water.
American Chemical Society, Washington, D.C.
Congress of the United States, OTA (Office of Technology Assessment). 1990. Beneath:
the Bottom Line: Agricultural Approaches to Reduce Agrichemical Contamination of
Groundwater. Washington, D.C: Government Printing Office. NTIS PB91-129874.
Enfield, G.G., R.F. Carsel, S.Z. Cohen, T. and D.M. Waiters. 1982. "PESTANS I and II,"
Ground Water 20:711 -722.
Geraghty & Miller, Inc., and ICF Incorporated. 1990. A Review of Methods for Assessing
the Sensitivity of Aquifers to Pesticide Contamination. Prepared for EPA's Office of
Ground Water Protection under Contract No. 68-C8-0003 with accompanying workbook
for the Boulder, CO, Workshop (July 24-25, 1990).
Gianessi, LP. 1986. A National Pesticide Usage Data Base. National Center for Food
and Agricultural Policy, Inc., Washington, D.C.
Gianessi, L.P., and C.A. Puffer. 1988. Use of Selected Pesticides in Agricultural Crop
Production by State. National Center for Food and Agricultural Policy.
t
Gianessi, L.P., and C.A. Puffer. November 9, 1990. The Use of Herbicides in the United
States. National Center for Food and Agricultural Policy. Presented at the National
Research Conference, "Pesticides in the Next Decade: The Challenges Ahead,"
sponsored by Virginia Water Resources Research Center, Richmond, VA.
Gianessi, L.P., and C.A. Puffer. January 1991. Estimation of County Pesticide Use on
Golf Courses and by Urban Applicators. National Center for Food and Agricultural Policy.
PB89-191100.
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Chapter 3
Goss, D. 1988. Soil-Pesticide Interaction Ratings (SPIFO System. U.S. Department of
Agriculture Soil Conservation System (addendum provided at Boulder Workshop).
Green, R.E., C.C.K. Liu, and N. Tamnaker. 1986. "Modeling Pesticides Movement in the
Unsaturated Zone of Hawaiian Soils Under Agricultural Use." In: Evaluation of Pesticides
in Ground Water. American Chemical Society, pp. 366-383.
Gustafson, D.I. 1989. "Ground Water Ubiquity Score: A Sample Method for Assessing
Pesticide teachability." Environmental Toxicology and Chemistry 8:339-357.
Hansen, D.T. 1990. "Description of the Data Directory of the San Joaquin Valley
Drainage Program." Proceedings of the Tenth Annual ESRI User Conference, V. 2.
Khan, M.A., and T. Liang. 1989. "Mapping Pesticide Contamination Potential."
Environmental Management 13:233-242.
Kissel, D.E., O.W. Bidwell, and J.F. Kientz. 1982. Leaching Classes of Kansas Soils.
Kansas State University, Kansas Agricultural Experiment Station, Manhattan, KS. Bulletin
641.10pp.
Knisel, W.G., Ed. 1980. CREAMS: A Field-Scale Model for Chemical. Runoff, and
Erosion from Agricultural Management Systems. USDA, Science Education
Administration. Conservabon Report No. 26.
Lo, T.H. C., S.E. Dicks, and R. Christiansen. 1990. "Identification of Natural Resource
Lands for Acquisition within the Context of ARC/INFO GIS Framework." Proceedings of
the Tenth Annual ESRI User Conference, V. 2.
Maine Board of Pesticides Control. November, 1990. Draft Pesticides in Ground Water
Management Plan.
Moore, J.S, 1988. SEEPAGE: A System for Early Evaluation of the Pollution Potential
of Agricultural Ground Water Environments. USDA, Soil Conservation Service, Chester,
PA. 1 p.
Moreau, D.H. and LE. Danielson. 1990. Agricultural Pesticides and Groundwat'er in
North Carolina: Identification of the Most Vulnerable Areas. Water Resources Institute
of the North Carolina State University, Raleigh. Report No. 252. NTIS PB90-235359.
Nofziger, D.L, and A.G. Hornsby. 1985. Chemical Movement in Layered Soil: User's
Guide. University of Florida, Gainesville.
Pacenka, S. 1984. Diagnosing the Causes of Ground Water Contamination Using a
Mathematical Model: Report on Technology Transfer Workshop. U.S. Geological Survey,
Water Resources Division, Reston, VA. USGS/G-859(23). NTIS PB85-217008. 42 pp.
Page 3-43
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Chapter 3
Piat, A.S., D.R.G. Farrow, J.A. Lowe, and PA Pacheco. 1989. Agricultural Pesticide Use
in Estuarine Drainage Areas: A Preliminary Summary for Selected Pesticides. NOAA,
Strategic Assessment Branch, National Coastal Pollution Discharge Inventory Program,
Rockville, MD.
Rundquist, Rodekohr et al. 1991. "Statewide Groundwater Vulnerability Assessment in
Nebraska Using the DRASTIC/GIS Model." Geocanto International 6(2):51-58.
Sacha, L, D. Fleming, and H. Wysocki. 1987. Survey .of Pesticides Used in Selected
Areas Having Vulnerable Ground Waters in Washington State. U.S. EPA, Seattle, WA.
EPA 910/9-87/169.NTIS PB88-199674. 324 pp.
Scott, A.J. 1990. "Using a GIS for Analytical Modeling of Wellhead Protection Areas
Around Public Water Supply Wells." Proceedings of the Tenth Annual ESRI User
Conference. V. 1.
Sham, C.H. 1990. "Comments on Selecting a Geographic Information System for
Environmental Management." Environmental Management 14:3.
Steichen, J., J. Koelliker, D. Grosh, A. Heiman, R. Yearout, and V. Robbins. 1988.
"Contamination of Farmstead Wells by .Pesticides, Volatile Organics, and Inorganic
Chemicals in Kansas." Ground Water Monitoring Review 8:153-160.
Teso, R.R., T. Younglove, M.R. Peterson, D.L Sheeks, and R.E. Gallavah. 1988. "Soil
Taxonomy and Surveys: Classification of Areal Sensitivity to Pesticide Contamination of
Ground Water." Journal of Soil and Water Conservation 43:348-352.
USDA Water Quality Initiative Team. 1990. Bibliography: Cooperative Extension
System's Water Quality Educational Materials. USDA, Cooperative Extension Service.
U.S. EPA. 1987. "Pesticides and the Consumer." EPA Journal 13(4).
U.S. EPA. 1991. A Review of Methods for Assessing Nonpoint Source Contaminated
Ground Water Discharge to Surface Water.
U.S. EPA. 1991. Pesticides in Ground Water Data Base: 1991 Draft Report. OPtS.
U.S. EPA. 1993. A Review of Methods for Assessing Aquifer Sensitivity and Ground
Water Vulnerability to Pesticide Contamination. EPA 813-R-93-002.
U.S. EPA. 1992. Handbook for State Ground Water Managers: Using EPA Ground
Water-Related Grants to Support the Development and Implementation of Comprehensive
State Ground Water Protection Programs. EPA 813-B-92-001.
Wagenet, R.J., and J.L Hutson. 1986. "Predicting the Fate of Nonvolatile Pesticides in
the Unsaturated Zone." Journal of Environmental Quality 15:315-322.
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^Chapter 3
Warnecke, L. 1990. "GIS in the States: Applications Abound." G/S World 3:3.
Wisconsin Department of Natural Resources and the Wisconsin Geological and Natural
History Survey. 1987. Ground Water Contamination Susceptibility in Wisconsin.
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Chapter 4
Chapter 4
Prevention Components of SMPs
EPA's Pesticides and Ground Water Strategy emphasizes reducing unreasonable
risks of pesticide contamination of ground water by managing pesticide use in a way that
reduces or eliminates the leaching of pesticides to ground water in vulnerable areas.
SMPs must identify general management measures designed to prevent ground water
contamination associated with the use of registered pesticides in accordance with EPA-
approved labelling. The prevention components of SMPs should include measures that
will reduce or eliminate the risk of direct contamination of ground water, the risk of
pesticides leaching into ground water in vulnerable areas, and the risk of ground water
contamination resulting from normal agricultural practices. A State should tailor its
preventive measures according to the State's farm practices and pesticides use; the
State's unique hydrogeologic circumstances; the use, value and vulnerability of the
State's ground water resource; and the State's regulatory structure for pesticide and
water quality management. Each State has a unique set of circumstances in which to
determine the appropriate preventive measures. In determining measures, States will
need to convene those individuals from State agencies, USGS, and USDA (e.g., Soil
Conservation Service, Extension Service) who have experience and knowledge about the
specific State conditions.
A State must develop and implement measures to prevent ground water
contamination from pesticides. When a specific pesticide is found in ground water, the
preventive measures must be applicable to the pesticide and the target crop the pesticide
is applied to. The Guidance for Pesticides and Ground Water State Management Plans
provides that both a State's Generic SMP and a Pesticide SMP should:
Address the types of preventive measures that will be implemented
in the absence of actual detection of pesticides in ground water
which the State has deemed to be valuable or vulnerable. Indicate
how prevention measures will be reevaluated and what increasingly
stringent types of measures will be imposed if contamination of
ground water is found or is increasing toward the reference point. -
The SMP must also indicate the factors and rationale considered in ,
choosing these measures and the triggers that would lead to a
State's implementation of more stringent measures. At a minimum,
confirmed detections of a pesticide in ground water need to be
treated as a cause for concern and should trigger some action to
diagnose the cause of the particular detection and determine
whether any further regulatory/management approaches are needed.
For example, a State may indicate that it will implement educational
efforts regarding source reduction of pesticides, even when the
pesticide has not been detected in ground water; that if detections
are confirmed in ground water the State will move to measures that
Page 4-1
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Chapter 4
involve enforceable use limitations; and that if the level of a pesticide
or breakdown product in ground water is found to be increasing
toward the MCL or other established reference point, the State will
implement use prohibitions.
In addition to the Generic Plan Criteria listed above, a Pesticide Plan must:
Identify specific preventive approaches (i.e., specific application
rates, specific tilling practices or other best management practices,
use restrictions and prohibitions, etc.) that will be employed on a
voluntary or required basis. Pesticide SMPs should be self adjusting
and include a range of contingency plans that would be triggered by
pesticide detections found in ground water, or new information on
the level of risk posed by the contamination, pesticide usage
patterns, as well as ground water vulnerability, use and value.
Explain the rationale for the specific prevention measures chosen
and indicate the feasibility of implementing those measures. For
example, the plan could briefly document how the specific prevention
measures have been used successfully in the State or, for new
measures, the results of research or demonstration trials where the;
measures have been shown to be effective. ::,
Describe at what levels of detection (from zero to the reference
point) the State will implement certain prevention or response
measures. (See EPA's Policy on Use of Quality Standards, page 3-
15 of Guidance for Pesticides and Ground Water State Management
Plans.)
In establishing preventive steps and response actions the State
should consider, among other factors, the level of contamination
compared to the MCL or other established reference point. Where
a pesticide has or is considered likely to reach reference points
(reaching the reference point marks the point of failure of the ground
water protection goal), the most stringent actions should be taken to
stop further contamination. These actions can range from
enforcement actions to modification of the way a pesticide is
managed, including geographically-defined prohibitions or moratoria
on the pesticide's use. (See Component 8.)
Address potential adverse impacts of the specific measures
employed by a State to surface water in addition to ground water.
For example, the p!an would address whether a change in a tillage
practice instituted to reduce ground water contamination infiltration
may in some instances increase surface water runoff. In addition, if
a State expects that a risk reduction measure will lead users to use
Page 4-2
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Chapter 4
alternative chemicals, then EPA encourages the State to consider
whether the alternative chemicals will .cause adverse effects for
ground water, surface water or other areas. (EPA rulemaking will
have analyzed the most likely alternative chemicals including their
risks and benefits.)
EPA also strongly encourages States to implement measures to
protect surface water from pesticide contamination that is likely to
impair water quality.
The preventive measures a State chooses to implement may vary based on
ground water use value, and vulnerability, pesticides use, and social and economic
factors. The measures may range from education efforts to use limitations or prohibitions
in certain areas. Particular emphasis is placed on the protection of sensitive aquifers.
The stringency of preventive measures may vary, however, from State to State and even
within a State as a reflection of differences in pesticide usage and/or aquifer sensitivity.
EPA encourages States to adopt best management practices (BMPs), integrated pest
and crop management (IPM/ICM) practices, sustainable agriculture, and other
approaches that result in reduced risk of ground water contamination, even in the
absence of concern regarding a specific pesticide. SMPs should provide a range of
prevention alternatives implemented both prior to and after a chemical's detection in
ground water. Provisions for evaluating the success of preventive measures should be
an integral part of a prevention plan.
EPA recognizes that a number of existing State programs implement ground water
protection and preventive measures. Table 2-1 (Chapter 2) summarizes some existing
EPA programs which address ground water protection and nonpoint source
contamination. As described in Chapter 7, other federal agencies also administer
programs which parallel and support some components of SMPs (e.g., nonpoint source
programs authorized under the Coastal Zone Management Act). Whenever possible, a
State should coordinate common preventive measures with those developed for SMPs
to minimize duplication of effort.
This chapter focuses on the development of State plans to prevent ground water
contamination by pesticides. The measures presented in this chapter are suggestions
that should be evaluated and implemented as appropriate given the specific goals and
conditions in each State and the guidelines presented in Appendix A. Examples are
provided to encourage States that do not have specific management measures in place
to seek information from other States and to subsequently develop prevention strategies
appropriate to their State. This Chapter includes:
A description of how the prevention, monitoring, and response
components of SMPs are related;
An overview of management measures that protect ground water
from contamination;
Page 4-3
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Chapter 4
A framework for tailoring prevention plans to State-specific needs
and conditions; and
.A discussion of the State's implementation considerations.
4.1 Interrelatedness of the Prevention, Monitoring, and Response
Components
Preventive measures begin to overlap with monitoring and response measures at
the point that pesticide contamination of ground water is found. A response to a
detection may include instituting additional or different, more stringent, preventive
measures. EPA encourages States to adopt preventive measures before contamination
is found to reduce the risk that pesticides will reach ground water. The stringency of
preventive measures to protect ground water should increase with an aquifer's sensitivity
or as concentrations of detected pesticides approach reference points. Figure 4-1
depicts the potential relationship between these prevention, monitoring, and response
components and the integral part that ground water monitoring plays in devising
prevention strategies.
The SMP approach incorporates EPA's policy of using reference points: to
determine the level of stringency for ground water protection activities. Reference points
should be applied differently for prevention and response purposes. For prevention
activities, detection of a pesticide at a percentage of the reference point triggers
additional prevention actions, such as limiting the use of the pesticide. In general,
detection of a pesticide at or above the reference point initiates the State's response to
stop further contamination (e.g., banning the use of the pesticide in the area). It is
important to recognize that the use of reference points is not a "license to pollute."
Rather, reference points serve as means to define failure of preventive measures and to
generally identify the need for the most stringent measures to protect ground water from
further pesticide contamination. In specific instances, considerations such as ground
water use, value, vulnerability, and social and economic values may play a part in
determining appropriate response measures.
4.2 Measures that Protect Ground Water from Pesticide Contamination
In developing the prevention component of both Generic SMPs and Pesticide
SMPs, States should consider the foiiowing four main approaches to ground water
protection:
Measures that controi sources of direct pesticide contamination of
ground water;
Measures that iimit the use of pesticides;
Page 4-4
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TJ
03
(O
(D
EXHIBIT 4-1
RELATIONSHIP AMONG PREVENTION, MONITORING, AND RESPONSE
Continue to implement
initial prevention measures
Develop and implement ..'*
response plan and
develop and implement
additional and/or more
stringent prevention measures
X t
v
Implement the response plan
and the most stringent
prevention measures necessary
x percent of reference point
' \
V
reference point
Detection of a concentration at an increased percentage of the reference point
01
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Chapter 4 .
Measures that reduce the potential for pesticide leaching to ground
water; and
Measures that reduce the quantity, toxicity, or persistence of
pesticides used.
Descriptions and examples of each category of preventive measures are presented in the
." following sections, the discussions address a range of options for increasingly stringent
implementation of each preventive measure.
4.2.1 Measures that Control Sources of Direct Pesticide Contamination of Ground
Water
Although pesticides have numerous beneficial uses, pesticides also pose a risk of
direct contamination of ground water. Studies in a number of States suggest that high
pesticide concentrations in ground water may be attributed to improper handling, loading,
storage or disposal of pesticides (U.S EPA, 1988). Therefore, proper handling, storage,
and disposal of pesticides and proper well construction and abandonment practices may
minimize the potential for pesticides to enter ground water directly. State SMPs should
address how to identify potential point sources of contamination (e.g., .locations of
pesticide storage and distribution centers). In addition, SMPs should address; how
appropriate pesticide handling practices and proper well construction and "abandonment
practices that minimize the potential for direct transport of pesticides to the water table
wilkbe achieved.
Pesticide Handling, Storage, and Disposal
Improper handling, storage, or disposal of pesticides may result in the release of
these materials into ground water at concentrations that greatly exceed those of routine
application. The FIFRA 88 amendments expanded EPA's authority to regulate storage,
transportation, and disposal of pesticides beyond the rules currently found in 40 CFR Part
165. EPA has conducted studies of pesticide container design and may take additional
regulatory action in the future (see 56 Federal Register 54025, October 21,1991).
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Chapter 4
The State of Wisconsin identified numerous sites where pesticide handling,
storage, or disposal resulted in ground water contamination. As a result, the Wisconsin
Department of Agriculture, Trade, and Consumer Protection developed administrative rules
and guidance covering proper pesticide handling and storage; secondary containment
requirements for mixing, loading, and storage areas; response plans for environmental
discharges; and detailed recordkeeping. For further information on pesticide handling
practices in Wisconsin, contact the Wisconsin Department of Agriculture, -Trade, and
Consumer Protection, 801 West Badger Road, Post Office Box 8911, Madison, Wisconsin
54708-8911; Telephone: (608) 266-2295.
As the example from Wisconsin indicates, States can also implement prevention
programs that minimize the risk posed by improper handling, storage, or disposal of
pesticides in either a Generic or a Pesticide SMP.
In managing pesticide use to prevent direct contamination from pesticides, a State
should recognize the importance of:
Location factors;
Spill or leak factors;
. Application factors; and
Pollution prevention factors.
Consideration of each factor influences the implementation of selected pesticide
management practices. Table 4-1 presents a variety of pesticide management practices
recommended to protect ground water resources from pesticides contamination. The
table demonstrates how management practices can be applied to specific pesticide use
activities (e.g., mixing, loading, rinsing, storage, and disposal).
The Minnesota Department of Agriculture has addressed the proper disposal of
waste pesticide materials via rinse and load setbacks. As a component of voluntary BMPs
for Atrazine, the Minnesota Department of Agriculture has proposed rinse and load
setbacks from wells, sinkholes, or surface water of 150 feet (Minnesota Department of
Agriculture, 1990b). In addition, the State conducted a pilot project on container collectipn
and recycling to promote county-based pesticide container programs. For further
information on pesticide disposal practices in Minnesota, contact the Minnesota
Department of Agriculture, 90 West Plato Boulevard, St. Paul, Minnesota 55107; Telephone:
(612)297-7264. : '
The preparation and application of pesticides provides numerous opportunities for
spills, accidents, and leaks. Improperly disposed pesticide wastes provide concentrated
point sources of contamination that could adversely affect ground water quality. A State
should address improper pesticide use or application through certification and training
Page 4-7
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Chapter 4
Table 4-1. Examples of Pesticide Management Practices for Ground Water
Protection
Pesticide Management Practices
Location Factors:
Away from wells
Away from sinkholes/other conduits to
ground water
On impervious pads or foundations .
Spill or Leak Factors:
Care in handling containers
Covered storage areas
Spill containment measures (dikes or
berms)
Routine inspection of facilities
Inventory of materials
Emergency response planning for
releases
Availability of Material Safety Data
Sheets (MSDS)
Application Factors:
Use of closed systems
Use of anti-backsiphoning techniques
Maintenance of application equipment
Calibration of application equipment
Use of certified applicators
Pollution Prevention/Waste
Minimization Factors:
Following label instructions
Reduction of leftover tank mixes
Spraying of rinse water on cultivated
fiCklHo
Inventory Control
Pesticide Use Activities
Mixing
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Page 4-8
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Chapter 4
programs and continuing education programs for pesticide applicators. Proper storage
and disposal of pesticides can also be addressed through technical assistance and
public outreach.
A State may institute increasingly stringent preventive measures for pesticides
handling, storage, and disposal depending on the risk posed by a specific pesticide. For
example, karst or other hydrogeologically sensitive areas may require special preventive
measures, because accidental spills or leaks in these areas may be transmitted directly
and quickly to ground water. However, EPA encourages States to implement prevention
management practices for pesticides handling, storage, and disposal throughout the
State to ensure that the risk posed by direct contamination of ground water is significantly
reduced.
Proper Well Construction and Abandonment
Improper seals on active or abandoned wells provide direct pathways for
pesticides and agricultural runoff to reach ground water and impact drinking water
supplies. Proper construction of wells minimizes the potential for direct transmission of
pesticides along the borehole to the ground water. A State well water program
addresses these potential sources of contamination through practices such as:
Well construction standards, including well casings, seals, and
surface completions;
Requiring well drillers or well owners to file completion reports for
new domestic wells;
Regulating underground injections;
Certification and ongoing education programs for well drillers, pump
installers, and test samplers;
Inspections of wells and enforcement of well construction standards
and abandonment standards; and
Public education and outreach programs for private well users.
In addition to new wells, States should consider applying these standards to older wells,
irrigation wells, or agricultural drainage wells. Poor construction or maintenance of these
conduits can transport pesticide-laden field runoff to ground water.
In addition, poorly sealed abandoned wells may transmit runoff from agricultural
fields to ground water. Simple backfilling of abandoned wells may not be sufficient to
prevent the vertical movement of water from the land surface to ground water. A State
should consider the development and implementation of proper well abandonment
procedures, including:
Page 4-9
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Chapter 4
Removing the well casing;
Filling the borehole with grout or other low-permeability materials;
and
Placing a concrete cap over the plugged hole.
Although many States maintain standards and guidance on the proper abandonment of
wells and subsurface conduits, such standards are often difficult to enforce (Aller et al.,
1990). Therefore, a State should consider developing inspection and enforcement
programs to ensure properly abandoned wells. As an alternative some States require the
reporting of well abandonment procedures and materials (Wisconsin Department of
Natural Resources, 1985).
A State may take the preventive measures described above separately or in
combination with other measures. A State may institute increasingly stringent preventive
measures relating to well construction, use, and abandonment depending on the risk
posed by a specific pesticide to wells within a State. For example, a State may choose
to conduct inspections of private wells in hydrogeologically sensitive areas. However,
EPA encourages States to implement preventive measures for well construction, use, and;
abandonment throughout the State to ensure that the risk posed by direct contamination
of ground water is significantly reduced. :
4.2.2 Use Limitations or Prohibitions
Limitations on pesticide use can be an effective tool to protect against pesticide
contamination of ground water. Use limitations can apply both to application techniques
and/or to geographic settings. In addition, limitations could become increasingly stringent
if pesticides are found in ground water, or are moving toward the reference point.
Pesticides Application Limitations
Measures that encourage farmers to select pesticide application methods that
discourage leaching to ground water may reduce the risk of ground water contamination.
Such preventive measures range from voluntary practices to label requirements on
pesticides. Preventive measures associated with pesticide application iimitations include:
i
Requiring comprehensive education and training for pesticide
applicators;
Requiring proper calibration and maintenance of application
equipment;
Page 4-10
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Chapter 4
Limiting the timing and frequency of pesticide applications to
coincide with periods of lower infiltration; and
Limiting aerial and ground-based application of pesticides.
Applicator Education and Training. Under FIFRA, all States must have a
.satisfactory certification program administered either by EPA or a State agency for
pesticide applicators so they can legally use restricted-use pesticides. EPA classifies a
pesticide in the restricted-use category if the pesticide may cause unreasonable adverse
effects to the environment or injury to the applicator. EPA's Office of Pesticide Programs,
Certification and Training (C&T) program assists State FIFF1A agencies, State land grant
universities, and the USDA Cooperative Extension Service in offering training programs
to certify commercial and private pesticide applicators. Recently, the President's Water
Quality Initiative strengthened the USDA's involvement in the C&T program.
In either a Generic or a Pesticide SMP, a State may describe its plans to enhance
applicator training and testing requirements for specific pesticides that pose a significant
threat to human health and the environment through ground water contamination. Such
requirements would better inform pesticide applicators of the risk of pesticide
contamination to ground water and how to minimize that risk.
Wisconsin's Atrazine Rule for 1991 requires a reduced application rate of one
pound per acre per year for coarse soils and 1.5 pounds for medium and fine soils If
atrazine was used the previous year. If atrazine was not used the previous year, the rule
requires a reduced application rate of 1.5 pounds per acre per year for coarse soils and
two pounds per acre per year for medium and fine soils. For the tower Wisconsin River
Valley, atrazine use is limited to 0.75 pounds per acre per year on sand or loamy sand.
In all areas of Wisconsin, atrazine use is restricted to certified applicators, application is
prohibited before April 15 or after July 31, and cannot be applied through irrigation
systems. In addition, irrigation is prohibited on any field for two years after atrazine
application unless an irrigation scheduling program is used. Applicators must complete
a record of use on the day of application for each field treated. These records must be
kept for three years. For more information on Wisconsin's Atrazine Rule, contact the
Wisconsin Department of Agriculture, Trade, and Consumer Protection, Agricultural
Resource Management Division; Telephone: (608) 266-2295.
Requirements for Calibration and Maintenance of Application Equipment. Proper
maintenance and calibration of pesticide application equipment is critical to ensure even
application of pesticides and accurate application rates. Poorly maintained or calibrated
equipment results in excessive discharges of concentrated pesticides and the subsequent
leaching of pesticides to ground water. Pesticide application equipment should'be
maintained and calibrated periodically to ensure accurate pesticide delivery volumes.
Properly maintained automatic volume-regulating devices, which function by varying spray
pressure according to the speed of the application equipment, are helpful in maintaining
appropriate pesticide application rates.
Page 4-11
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Chapter 4
Through an SMP, a State can limit pesticide application to specific equipment or
calibrations. In addition, a State may require the testing and inspection of pesticides
application equipment to ensure proper maintenance and calibration. Such requirements
ensure the proper maintenance and calibration of application equipment to reduce the
risk of pesticide contamination of ground water.
Limitations on Application Timing. Rate, and Frequency. The timing, rate, and
frequency of pesticides application is an additional factor in its potential to leach into
ground water. Applying pesticides during a period of lower infiltration, or reducing the
rate of application pesticide applicators may enhance the safe and effective utilization of
pesticides.
Through an SMP, a State may choose to limit pesticide application to certain
periods during the year and with prescribed frequency. Such restrictions on the time and
frequency of pesticide application can significantly reduce the risk of pesticide
contamination of ground water.
Limitations on Aerial and Ground-Based Application. Aerial application of
agricultural pesticides is accomplished by spraying pesticides from airplanes or
helicopters. Uniform application to foliar surfaces may vary due to wind conditions during
application periods. Consideration of wind patterns and weather conditions is necessary
to ensure uniform application rates and to minimize the likelihood that pesticide
concentrations will impact surface waters.
California, Arizona, and Hawaii have statutory authorities which requires reporting
of environmental fate data relating to ground water pollution for agricultural pesticides.
These States also have regulatory authorities to impose use limitations or prohibitions,
require monitoring, and require special applicator training to reduce the contamination risk
in vulnerable areas. ;
Pesticides may be applied to foliar surfaces, the ground surface, or incorporated
into soil using a number of ground-based application methods. In general, soil
application methods pose a greater potential for leaching to ground water than do foliar
application methods.
Through an SMP, a State may limit aerial or ground-based application of pesticides
to certain time periods or geographic areas. Such limitations could be increasingly
stringent based on the pesticide's potential for leaching to ground water. Restrictions on
pesticide application methods can significantly reduce tne risk of pesticide contamination
of ground water.
Page 4-12
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Chapter 4
Geographic Settings Limitations
Limiting the use of pesticides in the area around water supply wells, well recharge
areas, or other sensitive hydrogeologic settings may reduce the risks from pesticide
contamination of ground water resources. Two approaches to utilizing geographic
settings are:
Establishing more stringent preventive measures for more sensitive
hydrogeologic settings; or
Limiting or prohibiting the use of pesticides in sensitive
hydrogeologic settings.
Specific preventive measures or limitations can be stipulated in the SMP or as.label
requirements on pesticides. The most stringent and most protective preventive measure
is a moratorium on pesticide use in a particular area of the State that is susceptible to
ground water contamination.
Through assessments of aquifer sensitivity and ground water vulnerability efforts,
a State can tailor the preventive measures of its Generic and Pesticides SMPs to its
unique hydrogeologic settings. A State should consider the following types of
geographic settings or areas for potential pesticides use limitation or implementation of
other more stringent preventive measures:
Wellhead protection areas for public water supply wells;
Wellhead protection areas for private water supply wells;
Sole Source Aquifers; and
Other areas identified in the State's ground water resource
assessment and characterization.
Wellhead Protection Programs for Public Water Supply Programs. Wellhead
protection areas are used to prevent the contamination of ground water used as a public
watef supply. The concept of protecting ground water supplies in the vicinity of public
drinking water wells is central to the Wellhead Protection Program, authorized by the11986
amendments to the Safe Drinking Water Act. EPA has approved 31 State Wellhead
Protection Program plans and several more are currently under review. A number of local
wellhead protection efforts also exist.
Guidance on the establishment and management of buffer zones, or Wellhead
Protection Areas (WHPAs), is available from EPA's Office of Ground Water and Drinking
Water (U.S. EPA, 1987). State Wellhead Protection Programs provide technical
assistance and other support to local communities interested in protecting wellhead areas
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EPA Region I, the Connecticut Department of Environmental Protection (DEP),
and the USDA Soil Conservation Service (Connecticut State Office) conducted a pilot
study in the town of Cheshire. As part of this effort, a variety of local ordinances, bylaws,
and inspection programs were developed. Hie work completed under this study was used
in developing The Manual of Best Management Practices for Agriculture: Guidelines for
Protecting Connecticut's Water Resources.
Another approach to wellhead protection is the Massachusetts Aquifer Lands
Acquisition Program. This program enables the Massachusetts Department of
Environmental Quality Engineering to reimburse communities which purchase the land or
easements necessary to secure buffer areas around wellfields. Currently, Massachusetts
implements half-mile protection zones around community wellhead areas. Adjustments will
be made as more precise recharge areas are calculated.
or aquifer recharge areas. State authorities should coordinate Wellhead Protection
Programs and SMPs.
Wellhead Protection Areas for Private Water Supply Wells. Some existing,State
ground water protection efforts focus on protection of areas around private water supply -
wells, which supply drinking water to families on farmsteads and other rural residences.-
Local efforts and resulting resident actions may in effect result in a wellhead protection.
plan for private wells.
The Farmstead Assessment System (Farm-A-Syst) could serve as the foundation
for the creation of a more comprehensive private wellhead protection plan. Farm-A-Syst
was developed in response to farmers' concerns about protecting water quality, and
because farmsteads (i.e., the farm buildings and the land around them) can be a major
source of rural water contamination. Farm-/\-Syst uses ten easy, step-by-step worksheets
that rank farmstead activities and structures (such as pesticide handling sites and
livestock waste storage areas) that could cause groundwater contamination. A separate
worksheet assesses how soil, geologic, and hydrologic features of the farmstead affect
the ground water pollution potential at that site. An overall evaluation worksheet is then
used to summarize voluntary actions that can be taken to protect drinking water.
Information on available financial, technical, and education assistance is also provided in
companion brochures.
Farm-A-Syst was initially developed as a cooperative project of EPA's Region V
Office and the Wisconsin and Minnesota Extension Services (ES). It is currently a national
effort supported by EPA, ES, and the Soil Conservation Service (SCS). A national staff
provides support to States interested in adapting the Wisconsin and Minnesota prototype
Farm-A-Syst program for their particular agricultural, programmatic, and regulatory
circumstances. As these modified State assessments are available across the country,
they become valuable tools for facilitating actions by farmers and rural residents tc
reduce drinking water contamination risks from pesticides and other farmstead sources.
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All pesticide management practices in Table 4-1 are addressed in the prototype
Farm-A-Syst. Proper well construction and management, noted in this guidance, is also,
facilitated by use of Farm-A-Syst. Other potential sources addressed by the system are
fertilizer and petroleum product storage and handling, household and farmstead
hazardous waste management, household wastewater management, livestock waste and
yards management, silage storage, and milking center wastewater management.
Sole Source Aquifer Program. Under the Safe Drinking Water Act, EPA designates
aquifers as a sole or principle source of drinking water jn order to maintain or improve
underground drinking water quality. Designation requires EPA review of federal
financially-assisted projects to ensure that ground water is being protected.
A Sole Source Aquifer Protection Plan includes a map showing the detailed
boundary of the critical protection area. Guidance on the establishment and management
of Sole Source Aquifer Areas is available from EPA's Office of Ground Water and Drinking
Water. A State's SMP should give special consideration to delineations of existing sole
source aquifer designations.
Ground Water Resource Assessment and Characterization. The Guidance for
Pesticides and Ground Water State Management Plans requires a State to describe in its
SMP the methods by which it identifies and differentiates the use, value, and vulnerability
of its ground water. One of the primary purposes of the assessment is to determine the
hydrogeologic settings most susceptible to pesticide leaching to ground water.
Once the assessment is completed, the State should develop appropriate
prevention and use limitations or prohibition measures. In areas with high aquifer
sensitivity and high ground water value and vulnerability, States should consider more
stringent preventive measures. In some settings where aquifer sensitivity and ground
water vulnerability are particularly high, a State may choose to ban the use of pesticides
completely or to prohibit the use of pesticides with high leaching potential.
4.2.3 Reduction of Leaching Potential
The selection of pesticides and application methods that reduce leaching to
ground water may lower the risk of ground water contamination. Both Generic and
Pesticide SMPs should discuss how States will encourage practices such as using
pesticides with low leaching potential, varying application and irrigation methods
according to ground water susceptibility, and timing carefully pesticide applications. In
general, management of pesticides as nonpoint sources for ground water contamination
should be addressed in SMPs. (See USDA 1991 for a bibliography of recent materials
on issues and techniques for managing nonpoint sources.)
Selecting Pesticides with Low Leaching Potential
In general, the leaching potential of a pesticide is related to the pesticide's
formulation, persistence, solubility, and sorption characteristics (U.S. EPA, 1988).
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Chapter 4
Therefore, the selection of pesticides with chemical traits that have low leaching potential
characteristics and are effective at pest control may provide the most successful ground
water protection option. Information on pesticides collected from pesticide leaching
methods (described in Chapter 3) may be useful in identifying pesticides with low
leaching potential for specific applications.
A pesticide's formulation can affect its leaching potential by, for example, delaying
or preventing the pesticide from reaching the soil surface. Formulations that use
hydrocarbon solvents or "stickers" may reduce the amount of pesticide that enters the soil
by promoting increased adherence of the pesticide to plant surfaces and reducing "wash-
off1 of the pesticide by rains or irrigation. Alternatively, granules and encapsulations may
reduce leaching by controlling the release of pesticides to the environment. Other
formulations such as wettable powders, soluble powders, liquids, aqueous concentrates,
and emulsifiable concentrates also affect short-term behavior of a pesticide. For example,
about 30 times more wettable powder will leach from the soil surface than emulsifiable
concentrate if both are applied before a rainfall. (Deer, 1988) :
The persistence of a pesticide affects its leaching potential by determining how
much of the pesticide remains by the time that it reaches the ground water. The method.
of application and specific atmospheric degradation factors such as volatilization and;
photodegradation may substantially reduce the amount of the pesticide that enters the
soil. Some pesticides may persist in or on plants and degrade rapidly when released to
the soil. The soil degradation characteristics of a pesticide will depend upon such factors
as soil moisture, temperature, soil oxygen status, and soil microbial populations.. ,
Pesticide solubility affects its leaching potential by influencing the concentration of
the pesticide in rain water which leaches. In general, pesticides with solubilities of less
than 1 ppm will tend to be very resistant to leaching.
The sorption characteristics of a pesticide affects the leaching potential of a
pesticide by delaying the transport of the pesticide through soils. This characteristic is
usually described in terms of a Koc value. This value measures the affinity of the pesticide
to soil particles. Koc values of 1000 or more have a high degree of affinity to the soil and
will tend to move very slowly through the soil.
Through an SMP, as a preventive measure, a State may encourage the use of
pesticides with low leaching potential or may choose to limit or prohibit the use' of a
pesticide with a high leaching potential in sensitive hydrogeologic settings, in addition,
a State may actively investigate and encourage the use of pesticides that would provide
the required pest control but are less susceptible to leaching.
Irrigation Practices
Irrigation strategies used in conjunction with pesticides can affect pesticide
transport to ground water. Irrigation methods, timing: volume, and frequency may all
affect whether pesticides may leach to ground water. In general, irrigation methods
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Chapter 4
should be chosen that best supply crop water requirements without causing excessive
leaching. Standard methods of applying water to agricultural fields may be grouped into'
flood or furrow irrigation, sprinkle irrigation, and trickle or drip irrigation.
Flood irrigation covers the surface of an entire field section with irrigation water
while furrow irrigation applies water to earthen channels between crop rows. In both
.instances, infiltration of the ponded water is limited by the hydraulic conductivity of the
soil, which may vary substantially in different parts of the field. Therefore, less restrictive
soil pathways may be present that would allow differential infiltration and leaching during
irrigation events. Less restrictive soil pathways that can increase water filtration in soils
commonly include worm channels and root channels left from decayed crops. In
addition, macropore spaces can develop during soil wetting and drying, freezing and
thawing, animal activity, and tillage practice.
Sprinkle irrigation systems function by spraying irrigation water onto fields.
Sprinkle irrigation systems impact ground water by washing foliar-applied pesticides from
plant surfaces and promoting soil infiltration. For this reason, degradation rates, plant
uptake rates, and irrigation schedules should be considered when planning pesticide
applications.
Trickle or drip irrigation systems function by applying water slowly to points either
directly on or beneath the soil surface. These systems are designed to apply irrigation
water to localized areas where crop roots are present. Localized application, if done
properly, reduces the amount of leaching over methods that apply irrigation water to the
entire field surface:
Chemigation is the term applied to the practice of injecting farm chemicals into
irrigation water before it is applied to cropped fields. Problems associated with
chemigation generally arise from mixing pesticides at irrigation wells and the direct
contamination of ground water through backsiphoning incidents (U.S. EPA, 1988). EPA
requires registrants of pesticide products to include specific use directions and
statements for application through irrigation systems (U.S. EPA, 1987). Several States
are moving to require a minimum set of safety features for use in chemigation systems.
The State of Florida's Pesticide Law explicitly requires anti-backsiphoning devices,
check valves, pressure switches, and metering pumps. Additional precautionary features
are specified if the irrigation water source comes from a public water system. Requiring
such a consistent set of safety features can be of great value if a State moves to institute
a system of field inspections. Clear specification of the required safety equipment
simplifies the job of the inspector. Having explicit requirements for safety devices also
simplifies the task of conducting training programs for irfjgators and pesticide applicators.
Through an SMP, a State may encourage the use of pesticide application
schedules and techniques compatible with specific irrigation practices. This management
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Chapter 4
practice would restrict the use of leachable pesticides to periods when irrigation waters
are not migrating through the soil.
Timing of Pesticide Applications
Leaching of pesticides to the ground water from non-irrigated croplands is likely
to be a more serious problem in many States than leaching associated with irrigation
practices. Most U.S. cropland is not irrigated but still is subject to potential leaching
caused by natural rainfall. Unlike irrigation, rainfall cannot.be scheduled to accommodate
pesticide applications. However, the potential for pesticide leaching may be reduced by
adjusting the timing of pesticide applications to avoid predicted rainfall. In practice, this
approach requires knowledge of impending pest problems before immediate action is
required to allow flexibility in application timing.
Through an SMP, a State may establish guidelines that discourage the use of
specific pesticides during a specified time period preceding predicted rainfall. In areas
which receive large amounts of rain with little warning during certain times of the year, a
State may choose to restrict the use of certain pesticides with a high leaching potential
during those periods.
4.2.4 Measures that Reduce the Quantity and Toxicity of Pesticides Used and
Integrated Pest Management
Integrated Pest Management (IPM) is a pest population management system that
anticipates damaging levels by using techniques such as natural enemies, pest-resistant
plants, cultural management, and judicious use of pesticides (National Research Council,
1989). IPM can significantly reduce the application of pesticides to crops, thus reducing
the risks of pesticide contamination of ground water (Bender, 1990). The USDA
estimated that agricultural pesticide use could decrease by as much as 40 percent
through widespread use of IPM techniques (USDA, 1985). A current information source
on the subject is the USDA bibliography on Water Quality Implications of Conservation
Tillage, available through the National Agricultural Library and the AGRICOLA data base.
For many crops with high per-acre rates of return, self-sustaining local 1PM
programs have been highly successful. Some of the best examples are in fruit growing
areas. The New Hampshire Fruit Growers' Association worked for years with the
Cooperative Extension Service to promote \PM initiatives (Wood, 1990). These efforts
have proved so successful that conventionally managed orchards are rare in New
Hampshire. ' ; '{: ./'" .";;....:.,:-vYv.';''>;-:;;-:-y-*U::<-<.'''-^:-:^--£:, .-..''
Knowledge of the surrounding environment is necessary to implement an effective
!PM program. Extension specialists or pest control experts should be consulted when
implementing IPM programs. Factors considered when designing and implementing IPM
programs include:
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Chapter 4
Understanding crop development cycles;
Understanding crop cultural requirements during different growth
stages;
Understanding the economics of crop production and marketing;
Identifying pests and understanding their impact on targeted crops;
Understanding how much pest damage can be tolerated before a
pest control action is justified (called the economically tolerable
threshold level);
Understanding the pest life cycle and the most effective time to .
implement pest control measures;
Understanding the methods and materials required to suppress the
targeted pest species most effectively; and
Understanding pest control impacts on the ecosystem.
Over the past decade, the main public support for IPM programs came from the
USDA Cooperative Extension Service in combination with research and technical services
provided by State land grant universities and their local agricultural extension systems
(Balling, 1990). Federal activities encouraged ongoing technical support services at the
State level and promoted the formation of local self-sustaining IPM organizations.
Support through EPA and the USDA, through the Nebraska Cooperative Extension
Service, helped farmers establish the Long Pine IPM Program, This Program provides a
framework to pool the costs of needed technical services. In the early stages, technical
support was derived from a variety of USDA programs through the ASCS and SCS. The
Program continues to receive technical assistance from the Nebraska Cooperative
Extension Service, but the Long Pine IPM Association is now largely self-sufficient at the
end of its 6-year involvement in the Rural Clean Water project (U.S. EPA, 1989).
The hallmarks of IPM programs are scouting and biological pest control measures.
These measures and others that provide alternative solutions to the problems caused by
agricultural pests are discussed in the following sections.
Reducing Pesticide Use Through Scouting
In assessing methods that reduce risks of pesticide contamination resulting from
routine agricultural use, EPA concluded that the most effective means of protecting
ground water resources is by reducing pesticide use (U.S. EPA, 1988). One of the most
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Chapter 4
effective ways of reducing pesticide use, on a farm-to-farm basis, is through scouting
practices. Scouting involves inspecting a field for pests and determining the extent of
pest infestation. Scouting assessments allow farmers to choose the appropriate
measures to effectively mitigate pest infestation problems. One direct benefit of scouting
is identifying the stages of pest development, allowing for treatment during the pest's
most susceptible Irfecycle stage. By applying pesticides when the pest is most
vulnerable, the quantity of pesticides required will decrease and may subsequently reduce
or eliminate the need for follow-up applications. Many farming practices include the use
of pesticides as preventative measures against possible future pest infestations. Scouting
also monitors pest populations and resultant crop damage to enable managers to apply
pesticides only when needed. If crop damage is within the economically tolerable
threshold level and knowledge of the pest's lifecycle determines that an infestation is not
imminent, unnecessary pesticide applications may be avoided.
The Michigan Department of Agriculture assisted scouting activities as part of the
Michigan Energy Conservation "Rrpgram/jJMECPjl^/^'jIFunding came from federal court
settlements involving oil overcharges during the petrpieum price controls of the 1970s.
Promoting IPM programs was one of the six main uses of these funds {Draeger, 1990).
Although oil overcharge funds for the MECP have hot been available since 1991, past
activities directed toward organizing local landowner groups and training scouting
personnel resulted in several ongoing local programs.
A successful scouting program requires trained personnel who can reliably sample
the pest population and interpret field measurements that relate to the population
dynamics of pests and relevant predator or parasite species. Scouting programs often
become self-sufficient after providing initial assistance. Often, the main hurdle is to
involve a sufficient number of farmer-operators to share the costs of technical services,
because individual landowners cannot usually afford scouting services. Although trained
professionals generally are needed to initiate a scouting program, farmers can acquire
the needed field sampling and interpretation skills. Over time, therefore, the costs of the
program should decrease.
States should consider the examples set by Nebraska and Michigan of using one-
time grants or other nonrenewable funding as a type of capital investment to organize
critical components of IPM programs in developing SMPs.
Biological Pest Control
The use of chemical agents to control crop pests may eventually reduce the
chemical's effectiveness due to increasing tolerance by the pests. In addition, the effect
of many chemical agents is not restricted to the target pest and may also harm natural
predators or parasites of the pest. Biological control techniques aim to enhance natural
mechanisms that contrc! pests at economically tolerable threshold levels (OTA, 1S30).
Several types of natural biological pest controls are available to growers. Controls such
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Chapter 4
as antagonists, increasing the populations of predators, and self-defense mechanisms
are successful with many pests. Bolstering natural enemies (e.g., parasites, predators,
and insect pathogens) are usually partially effective in limiting the population sizes of"
pests.
In addition to manipulating natural food chain relationships, .other methods of
biological pest control include importing and releasing exotic natural enemies, increasing
indigenous natural enemy populations, introducing insect diseases, and introducing insect
pheromones. For example, widespread use of Bacillus thurinaiensis. a bacteria which eat
larvae, effectively controls gypsy moth infestations.
One of the earliest applications of biological agents was the 19th century use of the
Vedalia lady beetle to control cottony-cushion scale on citrus in California, The State of
California, chiefly through long-standing research programs, has been a leader in
promoting biological controls. In addition to the use of predators, considerable success
has been achieved by using such species as chalcid wasps, whose young are parasites
on a variety of insect pests.
Many States release irradiated (and therefore sterile) male pest species to reduce
normal reproduction rates. This technique has been widely used in California on the
Med-fly and in Texas on the screw worm. Similar results are often be obtained by
introducing chemicals that mimic the properties of pest pheromones. These synthetic
hormones interfere with pest mating success and serve to control populations at tolerable
levels. Pheromones (or similar behavior-affecting agents called semiochemicals) can be
placed in bait attractors mixed with minute quantities of pesticides to achieve carefully
targeted control of pests. Such approaches were very successful in treating corn
rootworm in South Dakota (Madden and O'Connell, 1990).
Pest-Resistant Plant Varieties
Another method for limiting pesticide use is through strategic selection of crop
variety. This nonchemical practice is rapidly becoming the most-used form of pest
control in the United States. By one estimate, as much as 75 percent of the total U.S.
crop-producing acreage is planted with pest-resistant and disease-resistant plant varieties
(U.S. EPA, 1988). In addition, considerable research is underway to develop crops that
have heightened resistance to pests (National Research Council, 1989).
Pest-resistant plant varieties can either suppress pest infestation or recover from
pest damage. Use of pest-resistant varieties, in conjunction with other agricultural
practices such as scouting, tillage, and crop rotation, may effectively reduce the quantity
of pesticides used.
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Chapter 4
Tillage Practices
Tillage practices are generally employed to improve soil conditions for planting and
crop growth, and to disrupt weed growth. The type and timing of tillage practices
minimizes the amount of pesticides used by mechanically disturbing or destroying crop
pests or by more effectively bringing the pesticide in contact with the pest. However,
tillage operations increase the susceptibility of the surface soil to erosion and to possible
pesticide loss to surface waters (U.S. EPA, 1988). Conservation tillage techniques have
been developed to reduce both the rate of soil erosion and of herbicide use and can
reduce pesticide loss to surface waters. The use of conservation tillage techniques,
however, generally results in an increase of infiltration water. This results in more water
in the soil profile, which may increase the leaching potential of pesticides. The term
conservation tillage is often used to refer to such methods as no-till, ridge-till, strip-till,
mulch-till, and reduced-till. A full description of these methods may be obtained from the
Conservation Technology Information Center (1987). Some reduced tillage techniques
may require increased dependence on chemical pest control measures which leads to
increased pesticide usage. Therefore, careful consideration of the potential impacts to
ground water must be made in determining tillage practices. In many cases, tillage used
in combination with other management techniques such as contour farming, terracing,
or crop residue management helps minimize the potential for both surface and ground
water contamination by pesticides. (A bibliography of sources is available in USDA 1991,
QB91-145.) ;
Crop Rotation and Stripcropping
Crop rotation is the successive planting of different crops in the same field over
a period of years. Pest control is the most significant impact of the crop rotation
process. Crop rotation may serve to minimize pesticide usage by avoiding the buildup
of pest populations that may result from continuous cropping of a specific or similar crop.
Without an initially large pest population, the crop has a head start to become established
and better compete with pests before the pest population increases to the point that it
significantly damages the crop.
Stripcropping is a method that combines crop rotation with contour planting. It
involves rotating alternating strips of crops that are planted parallel to the contours of the
field. If one strip is of a relatively open field crop, such as corn, the other strip is usually
a grain crop, a sod, or a legume. The primary agricultural advantage of Stripcropping
is generally considered to be the reduction of soil erosion and surface runoff. The
benefits of crop rotation such as insect, weed, and nematode reduction are also
associated with Stripcropping practices (Maas et al.. 1984). In combination with tillage
practices, Stripcropping and crop rotation can significantly reduce the quantity of
pesticides necessary to maintain a crop (U.S. EPA, 1988).
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Chapter 4
Increasing Pesticide Application Efficiency
By increasing application efficiency, the total amount of pesticide needed to control
pest problems may be reduced. Highly efficient applications would concentrate the
pesticide on the target pest while minimizing the total amount of pesticide used. Pesticide
application techniques that reduce or avoid losses through wind drift and selectively place
.the pesticide provide greater application efficiency. Some examples of application
systems that provide increased efficiency are:
Directed drop nozzle spray systems that apply herbicides to weeds
under the crop canopy;
Wick applicators control application to weeds that touch the wick,
thereby avoiding application to nearby crop surfaces or the soil; and
Recirculating sprayers that collect and reuse pesticide not
intercepted by weeds.
Many different methods are available to apply pesticides that provide increased efficiency
of application when specific pesticides and specific conditions are carefully considered.
4.3 Implementation Approaches
The preventive measures described above can be implemented through different
approaches and by different levels of government. Implementation approaches include
both:
Non-regulatory efforts; and
Regulatory actions.
In addition, preventive measures can be implemented at different levels of
government, including:
Federal;
State;
Local; or
Special district.
A critical SMP component are contingency preventive measures that provide for
increasingly stringent controls on pesticide use when evidence indicates that initial
preventive measures are inadequate or have failed. In addition, areas of high vulnerability
may require increasingly preventive measures, even though the pesticide has not been
detected in ground water. A State should consider the need for increasingly stringent
preventive measures developing its prevention plan and selecting its implementation
approaches.
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Chapter 4
The approach proposed by the Minnesota Department of Agriculture for
management of atrazine relies on voluntary measures so long as pesticides are not found
in ground water at or above a designated action level. If BMPs are not effective in
prevention, then additional mandatory efforts may be required (Minnesota Department of
Agriculture, 1990b).
4.3.1 Non-Regulatory Efforts
States can use non-regulatory efforts to implement a variety of SMP preventive
measures. No penalties are assessed for noncompliance with non-regulatory
requirements, thus, allowing the farmer or pesticide user maximum flexibility in the
selection of appropriate practices for field-specific conditions. Non-regulatory efforts
include:
Information dissemination;
Public education and outreach;
Planning and technical assistance; and
Financial assistance (cost-share and loans).
Information Dissemination
Pesticide users are in the unique position of directly controlling the use of a
pesticide. For this reason, States should target users when disseminating information on
preventive measures. Examples of such programs include farmstead assessment
programs developed by many States, using the Farm-^-Syst model described earlier as
the starting point. These State pollution prevention tools enable farmers to analyze the
individual and combined effects on drinking water sources of farmstead activities and
structures, local soil and geologic features, and water-supply characteristics. These
programs also enable farmer development and implementation of action plans to reduce
identified risks. Because the programs are voluntary they are viewed positively by
participants and the participants are more willing to conduct and implement assessments
because they know that the results are for their use.
i
Under Component 11 of an SMP (Information Dissemination), SMP preventive
measures must be communicated to pesticide users and appropriate industry groups and
regulatory officials. These programs often rely on federal, State, and university specialists
to provide technical assistance and information on the leaching potential of pesticides and
associated preventive measures.
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Chapter 4
One example of such a program is the Farmstead Assessment System (Farm-A-
Syst) pilot project undertaken by the University of Wisconsin Extension, USDA
Cooperative Extension Service, Minnesota Extension Service, and EPA - Region 5.
Farm-A-Syst consists of a series of 12 worksheets designed to help farmers assess the
effectiveness of farmstead practices in protecting drinking water. The system enables
farmers to analyze the individual and combined areal effects of farmstead activities with
local soil, geologic features, and water-supply characteristics on drinking water supplies.
More information on the Farm-A-Syst program may be obtained from Susan Jones, Farm->A-
Syst Program, B142 Steenbock Library, 550 Babcock Drive, Madison, Wisconsin 53706-
1293. The telephone number is (608) 262-0024.
Public Education and Outreach
Non-regulatory preventive measures typically focus on public education about
which measures are effective in preventing pesticide contamination of ground water.
Component 10 of an SMP requires a State to demonstrate that the public will have
access during SMP development and will be informed of significant implementation
activities. Public education and outreach efforts should communicate to general public
concerning the State's pesticides management efforts.
Planning and Technical Assistance
Some of the preventive measures described above, such as Integrated Pest
Management (IPM), require long term planning by farmers. In addition, many farmers
need technical assistance to implement some of the IPM preventive measures. A State
should consider using planning and technical assistance as an implementation approach
to reduce the use of pesticides within the State. Technical assistance is also a useful tool
in implementing preventive measures for rural water well construction and abandonment.
4.3.2 Regulatory Actions
At times regulatory actions may be necessary to ensure proper implementation of
SMP preventive measures. Penalties could be assessed for noncompliance with
regulatory requirements, and these requirements, therefore, allow the State to enforc'e the
requirements of an SMP and better control sources of contamination. Regulatory efforts
include:
Certification programs;
Permits and advance notice;
Land use controls; and
Enforcement activities.
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Chapter 4
State Certification Programs for Pesticide Applicators
The EPA Office of Pesticide Program's Certification and Training (C&T) program
assists State FIFRA agencies, State land grant universities, and the USDA Cooperative
Extension Service training programs for certification of commercial and
private pesticide applicators.1 Training initiatives are widely viewed as desirable because
approximately half the actual applications of restricted-use pesticides are carried out by
noncertified assistants (OTA, 1990).
An overview of ground water information is presented in Protecting Groundwater:
A Guide for the Pesticide User. The Guide is a slide set storyboard developed for use in
certification and training courses. It can be purchased from the New York State Water
Resources Institute. Copies may be obtained from the New York State Water Resources
institute, CER, 468 Hollister Hall, Cornell University, Ithaca, New York 14853; Telephone:
607-255-7535.
Whether administered by EPA or a State agency, under FIFRA, all States must
have an EPA-approved certification program for pesticide applicators so applicators can
legally use restricted-use pesticides. EPA classifies a pesticide in the restricted-use.
category if the pesticide may cause unreasonable adverse effects on the environment or
injury to the applicator.
Florida has had requirements for applicator certification and testing for restricted
use pesticides since 1977. Additions to the Florida Pesticide Law in the mid-1980s
extended basic C&T requirements for restricted-use pesticides to applicator assistants
(Florida Department of Agriculture and Consumer Services, 1989).
California has a well-established licensing and certification program for hired
applicators or for applicators of restricted-use pesticides. Licenses and certificate holders
have a continuing education requirement which affords term an opportunity to obtain
information on ground water protection. Similarly, California has a ground water protection
training program for pest control advisors that write ground water protection advisories for
known teachers. These advisories pertain to the use of known leachers in designated
sensitive areas. The training program for pest control advisors must be repeated every two
years. This C&T program is of great value in California's system of Pesticide Management
Zones (PMZs).
1 Further information on applicator certification may be obtained from EPA's Office of
Pesticide Programs, Certification and Training Office; Telephone: (703) 305-7371.
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Chapter 4
State certification training programs should provide sufficient coverage of a number
of elements, including ground water contamination by pesticides. The ground water.
component of the course should define ground water, its importance, factors that
determine whether a pesticide will reach ground water (e.g., geology, hydrology, climate),
steps to avoid ground water contamination, pesticide characteristics that affect potential
ground water contamination, and the consequences of contaminating ground water.
Alternatively, a State certification program could be used as a forum to describe
the SMP requirements, including restrictions on pesticide use in certain areas. Because
ground water vulnerability varies with local hydrology, geology, and pesticide use, States
should discuss these local conditions with participants.
Permits or Advance Notice Programs
Permits can be required for pesticides in areas which are susceptible to leaching
or for certain pesticides in the entire State. Some States require that certain pesticides
be used or purchased only under a special permit from the State's Department of
Agriculture. Permit applications are usually required in writing, but oral applications are
sometimes accepted. Permit applications typically request information such as the name
and address of the pesticide applicator; name and formulation of the pesticide; where,
when, and quantity of the pesticide; method of application; and special controls or
precautions that will be exercised in the use of the pesticide.
Land Use Controls
Restricting the use of a pesticide in certain geographic areas is a stringent
preventive measure designed to limit pesticide contamination of ground water in high
value and vulnerability areas. Another land use restrictions is limiting storage and
disposal of pesticides to certain areas. As an implementation approach, land use
controls can effectively protect against pesticide contamination of ground water. In
developing an SMP, States must consider, however, that local governments traditionally
are responsible for instituting land use controls, such as zoning.
Enforcement Activities
Enforcement activities might become necessary to ensure compliance,'with
preventive measures and to control contamination sources. The SMP approach is based
on the premise that pesticide management and enforcement is best conducted at State
and local levels. A State should place emphasis on coordinating FIFRA, SDWA, RCRA,
and CERCLA enforcement activities of EPA-delegated programs as well as those
administered by EPA to identify responsible parties for ground water contamination as
a result of the misuse of pesticides, including disposal or leaks and spills.
Component 9 of an SMP, Enforcement Mechanisms, requires a State to describe
enforcement and compliance activities, including inspection, technical support, voluntary
compliance efforts, and penalty provisions. In addition, a State must discuss its
Page 4-27
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Chapter 4
enforcement authorities and capabilities to monitor compliance with the specific measures
included in the SMP.
4.3.3 Involvement of Each Level of Government
Different levels of government can implement the preventive measures and
implementation approaches outlined.
Federal Level
Because of each State's unique hydrogeologic, institutional, and demographic
characteristics, EPA believes that they are in the best position to manage specific
pesticide use. Therefore, EPA believes that delegation of certain pesticide management
authorities to the appropriate State, and local officials is desirable. To timely ensure
protection of ground water from pesticides contamination, EPA will move to actively
review and approve SMPs (See Appendix A).
EPA and USDA also provide technical and financial assistance that helps States
develop and implement preventive measures. Chapter 7 provides a detailed discussion
of sources of technical and financial assistance from both EPA and USDA.
USDA is currently implementing a number of new programs that are consistent
with the preventive measures of SMPs. These include:
Base Flexibility. The "base flexibility" in the 1990 Farm Bill allows
farmers who participate in federal commodity support programs to
rotate crops and plant a greater variety of crops on acres that were
previously tied to a specific crop. This change is expected to lead
to reduced pesticide and fertilizer use, since crop rotation, especially
with nitrogen-fixing legumes, is a recognized means for reducing the
need for artificial nitrogen fertilizer and for breaking the pest
infestation cycles that affect repeated plantings of the same crop;
Cost-Share. Cost-share programs will be offered to producers,
certain hydrologic units, and demonstration project areas across the
United States. Financial assistance will be coupled with intensive
education and technical assistance to encourage the adoption of '
environmentally sound practices and the achievement of area-wide
\ improvements in protection of water quality;
Agricultural Conservation Program. The Agricultural Conservation
Program supports special water quality projects focusing on water
quality problems identified by State and iocai water quality planning
aaencjes:
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Chapter 4
Water Quality Incentive Program. The Water Quality Incentive
Program provides farm-level planning to' reduce the use of fertilizer,
other crop nutrients, and pesticides to achieve water-quality
objectives. Participants receive incentive payments designed to
compensate for additional production costs and/or foregone
production values; and
The Conservation Reserve Program. The 1990 Farm Bill also
provides specific authority to enroll land in the Conservation Reserve
Program under water-quality criteria. The program is used to enroll
land in high priority watersheds, wellhead protection areas, and other
areas that, if taken out of production, would contribute to protection
of water resources.
State Level
EPA recognizes State governments as the appropriate level of government to
implement the provisions of an SMP. The Guidance Pesticides and Ground Water State
Management Plans provides the necessary flexibility for States to develop and implement
individually-tailored SMPs, but also ensures that States are accountable for the proper
management of a specific pesticide to protect against pesticide contamination of ground
water.
The preventive measures outlined above can be implemented and supported at
the State level by participating regulatory agencies. Many of the measures, such as
limitations and restriction, are generally best managed by the State. In addition, a State
has the flexibility to determine who will be responsible for implementing specific preventive
measures (Components 2 and 3).
Local Level
Local governments can also play a beneficial role in protecting ground water
through SMPs. Local governments are already involved in other water quality programs
such as Wellhead Protection Programs and Public Water Supply Programs. Local
governments can support State efforts in information dissemination and public education
and outreach.
i
Local governments can support the SMP through land use controls, such as
storage and disposal restrictions. Local governments can also.provide technical
assistance to rural well owners and operators to control direct sources of ground water
contamination through wells. '
Special District Level
Special districts exist for soil conservation and other agricultural activities. These
agricultural districts can support public outreach and technical assistance in the field. The
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Chapter 4
activities of these districts often include direct involvement with local farmers and can
provide a suitable forum for providing information to the regulated community.
4.4 Implementation Considerations
The preventive measures summarized in Section 4.2 and the implementation
approach summarized in Section 4.3 may be considered individually or in conjunction
with other measures and approaches to protect ground water. No single preventive
measure or implementation approach will be appropriate or equally effective in all
situations. When developing and implementing an SMP prevention plan, a State should
consider the following factors in the selection of preventive measures and implementation
approaches:
The effectiveness of a preventive measure in protecting ground water
resources;
The cost of instituting preventive measures;
The geographic areas in which preventive measures should be . ,
implemented;
The effects that ground water protection measures might have on ~\
other resources; and T
The use of reference points or action levels to determine appropriate
preventive measures to the levels of risk.
The stringency of preventive measures should be appropriate to the level of
protection needed. In general, areas of high ground water sensitivity and/or high
pesticide use will necessitate more stringent preventive measures. Conversely, in areas
characterized by low ground water vulnerability, less stringent preventive measures may
suffice to protect ground water. If pesticides are detected in ground water, the stringency
of preventive measures should increase as the number of detections or concentrations
approach a reference point (e.g., MCL, health advisory, interim health limit, or State action
ievel). Some factors to consider in developing and implementing preventive measures
of SMPs are presented below. In addition, examples of ground water and surface water
priority ranking systems are provided by Bottcher and Baldwin (undated), USDA (1990),
and Brach (undated).
4.4.1 Effectiveness for Ground Water Protection
A State evaluates the effectiveness of preventive measures through its monitoring
programs (Chapter 5). The effectiveness of preventive measures will vary with different
sgricu'tiira!, hydrogeo!ogic, and physical situations. A State's monitoring program should
provide necessary information on the effectiveness of current preventive measures. If a
State's monitoring program finds a prevention program ineffective through detection of
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Chapter 4
pesticides in ground water, then the State implements increasingly stringent preventive
measures. In some cases, an evaluation of effectiveness is best judged for groups of
practices rather than for a single preventive measure.
4.4.2 Economic Costs
States should select prevention practices that are effective in protecting ground
water as well as cost effective to implement. For example, if a rate reduction of a specific
pesticide is to be implemented, States should select .an application rate that is still
effective in reducing pests. Economic factors that should be considered in ranking
prevention options include:
Probable cost of pesticides to farmers. A lower application rate
for a specific pesticide may reduce the total volume of the pesticide
applied thus lowering the cost of pesticide application. Changing the
pesticide used, however, may or may not increase costs to the
farmer depending on the cost of the alternative pesticide.
Impact on crop yield and quality. The reduction in pesticide
application rates may increase the occurrence of insects, rodents, or
weeds resulting in lower crop yields and/or quality.
Labor or special equipment requirement. Additional labor may be
required to reduce the application rate of the specified pesticide or
to apply an alternative pesticide. New or upgraded equipment may
be necessary to reduce the application rate or to change to an
alternative pesticide (Brach, undated).
4.4.3 Geographic Extent
State protection priorities should be based, in addition to ground water
vulnerability, on the use and value of the ground water resources. Determining where to
implement preventive measures requires an understanding of aquifer sensitivity and
pesticide use (Chapter 3). As a result, implementation of preventive measures will vary
across the State. The geographic application of preventive measures may present a
problem, since what may be applicable to a region may be inappropriate on a farm-
specific basis.
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Chapter 4
For example, the voluntary atrazine best management practices proposed by the
Minnesota Department of Agriculture include application rate restrictions to areas of the
State where fractured rock aquifers (including karst conditions) or sand, loamy sand, or
sandy loam soils predominate (Minnesota Department of Agriculture, 1990b). Counties
within Minnesota that meet these conditions are specified. The user is cautioned, however,
that areas in every county of Minnesota may include one of these conditions, in addition,
atrazine management practices for all areas of the State include timing restrictions {i.e.,
application of atrazine may only occur between the spring thaw and the time that corn
plants reach 12 inches in height), distance limitations or buffer zones around sinkholes and
drainage wells, irrigation management measures, and container management measures.
Some types of management measures are more appropriately applied to either
large or small areas. Small geographic areas are most effectively micromanaged with
field-specific restrictions or permitting measures. Conversely, larger geographic areas are
more effectively managed with area-specific restrictions. Regional implementation of
preventive measures, therefore, should include sufficient flexibility to allow for local
variations in aquifer sensitivity and pesticide use. An assessment of the scale to which
individual prevention practices reasonably and effectively apply may help determine:the
priorities and selected options.
Another example States may wish to consider is to utilize management measures
such as Farm-,A-Syst type pollution prevention programs by specifically targeting the
programs to geographic areas of greater vulnerability to ground water contamination, or
where greater protection is warranted. For example, municipalities with farmsteads
located in or near public water supply wellhead protection areas may take extra measures
to prevent contamination by using farmstead assessments.
An example of geographic applications is the approach used in Wisconsin to
manage aldicarb and atrazine use. Aldicarb is used in small geographic areas
(approximately 60,000 acres) of the State. The management plan reflects this in instituting
field-specific use restrictions. Conversely, atrazine is the most commonly used agricultural
pesticide in Wisconsin and is applied to approximately 3.5 million acres. For this reason,
site-specific use restrictions have been instituted in recharge areas to major aquifers jn
Wisconsin. Also, Atrazine Management Areas have been established covering larger
geographic areas to manage the use of this pesticide. Further information concerning
pesticide management plans in Wisconsin may be obtained by contacting the Wisconsin
Department of Agriculture, Trade, and Consumer Protection, 801 West Badger Road, Post
Office Box 8911, Madison, Wisconsin 53708-8911; Telephone: (608) 266-2295.
Page 4-32
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Chapter 4
4.4.4 Impacts on Other Media
The effectiveness of a particular preventive measure at preventing ground water"
contamination may be directly related to the contamination of other media, most notably
surface water. The SMP approach closely links other programs that promote
environmental quality and reduces risks associated with pesticide use. Such issues as
the effects of individual practices on soil erosion, the quality of field runoff that may impact
surface water, accumulated pesticides in foods or plant residues, and air quality should
therefore be considered. An environmental quality assessment of the impacts of
prevention practices in the area may be derived based on consideration of impacts on
individual media (e.g., plants, soils, surface waters, and air).
4.4.5 Use of Reference Points or Action Levels
Consideration of preventive measures overlaps with monitoring (Chapter 5) and
response measures (Chapter 6) when pesticides are detected in ground water. As noted
in Section 4.1, the stringency of preventive measures to protect ground water from
pesticide risks should increase with increased aquifer sensitivity and as concentrations
of detected pesticides approach reference points. For this reason, the establishment of
reference points or action levels that trigger specific prevention and response measures
is a necessary prelude to the development of both prevention and response plans.
The EPA has promulgated Maximum Contaminant Levels (MCLs) for some
pesticides and compliance monitoring requirements for public water-supply systems.
These are part of the National Primary Drinking Water Standards authorized under the
Safe Drinking Water Act (40 CFR Part 141). Many States use the same criteria for
management of private water-supply wells. The EPA Office of Marine and Estuarine
Protection sets water quality standards for some pesticides under the Clean Water Act.2
These standards may be used as reference levels.for ecological effects of pesticide
contamination.
EPA will continue to emphasize the development and enforcement of MCLs and
Health Advisories (HAs) to ensure the quality of ground water and drinking water
supplies. EPA encourages States, however, to establish their own reference points or
action levels at fractions of these federal enforcement standards. Detections below
reference points should also trigger preventive actions to prevent contamination with the
potential to pose risks to human health and the environment. The SMP must indicate the
factors and rationale considered in choosing these measures and the triggers that would
lead to a State's implementation of more stringent measures. At a minimum, confirmed
detections of a pesticide in ground water should be treated as a cause for concern and
trigger an assessment of the cause of contamination and an evaluation of the
effectiveness of existing preventive measures.
2 For further information on water quality criteria and standards for aquatic life,
contact EPA's Office of Wetlands, Oceans and Watersheds at (202) 260-7166.
Page 4-33
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Chapter 4
4.5 References
Aller, L, T. Bennett, G. Hackett, R.J. Petty, J.H. Lehr, H. Sedoris, D.M. Nielsen, and
J.E. Denne. 1990. Handbook of Suggested Practices for the Design and Installation of
Ground Water Monitoring Wells. National Water Well Association. NTIS PB90-159807.
455 pp.
Bender, J. 1990. "Converting to Pesticide-Free Farming: Coping with Institutions."
Journal of Soil and Water Conservation 45(1):96-98.
Bottcher, A.B., and LB. Baldwin. Undated. General Guide for Selecting Agricultural
Water Quality Practices. Florida Cooperative Extension Service; Pamphlet SP-15. 5 pp.
Brach, J. Undated. Agriculture and Water Quality: Best Management Practices for
Minnesota. Minnesota Pollution Control Agency. 64 pp.
Congress of the United States, OTA (Office of Technology Assessment). 1990. Beneath
the Bottom Line: Agricultural approaches to Reduce Agrichemical Contamination of
Groundwater. OTA F-418.
Conservation Technology Information Center. 1987. National Survey of Conservation
Tillage Practices. National Association of Conservation Districts, Washington, D.C.
Deer, H.M. 1988. Pesticide Data on Potential Impacts to Ground and Surface Water.
USDA Cooperative Extension Service, Utah State University.
Draeger, C.L. 1990. "Sustainable Agriculture at Work." Journal of Soil and Water
Conservation 45(1):83-85.
Florida Department of Agriculture and Consumer Services. 1989. Florida Pesticide Law
and Rules. Chapter 487, Florida Statutes, pp. 1642-1657.
Ganley, M.C. 1989. "Availability and Content of Domestic Well Records in the United
States." Ground Water Monitoring Review, 9(4): 149-158.
i
Maas, R.P., S.A. Dressing, J. Spooner, M.D. Smolen, and F.J. Humenik. 1984. Best
Management Practices for Agricultural Nonpoint Source Control: Pesticides. National
Water Quality Evaluation Project. USDA Cooperative Agreement 12-05-300-472; EPA
Interagency Agreement AD-12-F-0-037-0. NTIS PB85-114247. 76pp.
Madden, J.P. and P.F. O'Connell. 1990. "LISA: Some Early Results." Journal of Soil and
Water Conservation 45(1) :61 -64.
Minnesota Department of Agriculture. 1989. "Pest Control." Chapter 18B, 1989
Minnesota Statutes. 32 pp.
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Chapter 4
Minnesota Department of Agriculture. 1990a. "1990 Amendments to 1989 Minnesota
Statutes." 14 pp.
Minnesota Department of Agriculture, Agronomy Services Division. 1990b. "Proposed
Voluntary Atrazine Best Management Practices." 2 pp.
.National Research Council. 1989. Alternative Agriculture. National Academy Press,
Washington, D.C. 448 pp.
USDA, Cooperative Extension Service. 1985. Cooperative Extension and Agricultural
Profitability - Integrated Pest Management Reduces Costs and Increases Income.
USDA, Soil Conservation Service. 1988. Water Quality Field Guide. SCS TP-160.
USDA, ASCS/ES/SCS. 1990. Water Quality Education and Technical Assistance Plan:
1990 Update. Agriculture Information Bulletin No. 598. 13 pp.
USDA. 1991. Water Quality Implications of Conservation Tillage: January 1980-Julv
1991. National Agricultural Library, Quick Bibliography Series. QB 91-145.
USDA. 1991. Managing Nonpoint Sources of Pollution: January 1982-Julv 1990.
National Agricultural Library, Quick Bibliography Series. QB 91-50.
U.S. EPA, Office of Ground Water Protection. 1987. Guidelines for Delineation of
Wellhead Protection Areas. EPA 440/6-87-010.
U.S. EPA, Office of the Administrator. 1992. Final Comprehensive State Ground Water
Protection Program Guidance. EPA 10O-R-93-001.
U.S. EPA. 1987. Notice to Manufacturers. Formulators. Producers, and Registrants of
Pesticide Products. PR Notice 87-1. 17pp.
U.S. EPA, Office of Ground Water Protection. 1988. Protecting Ground Water:
Pesticides and Agricultural Practices. EPA 440/6-88-001. NTIS PB88-230628. 53 pp.
U.S. EPA, Office of Water, Nonpoint Sources Branch. 1989. Rural Clean Water Program
1988 Workshop Proceedings. EPA 506/9-89/001.
Wisconsin Administrative Code. 1985. "Agriculture, Trade, and Consumer Protection,"
Chapter Ag 161. Fertilizer or Pesticide Substances in Ground Water: Regulatory
Program. Register, No. 357. pp. 667-680.
Wisconsin Department of Natural Resources, Bureau of Solid Waste Management. 1985.
Guidelines for Monitoring Well Installation. Appendix B. 35 pp.
Wood, S. 1990. "The Trials of a Fruit Grower." EPA Journal 16(3):37-40.
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Chapter 5
Chapter 5
Monitoring Elements of SMPs
Ground water monitoring plays an integral role in reducing and preventing the
future degradation of ground water from pesticide contamination. Monitoring is likewise
an integral part of evaluating the effectiveness of any mitigation measures taken. Under
the SMP approach, ground water monitoring is an ongoing activity which enhances a
number of preventive functions, including defining background ground water quality,
identifying contamination occurrences, evaluating the effectiveness of implemented
ground water protection measures, and assessing the success of response measures.
Monitoring is one tool, which used along with other tools, can assess where areas of
contamination exist. As a first step towards developing a monitoring program, States can
use existing wells to form a network to begin gaining baseline information on pesticide
contamination of ground water. It will take time for the results of preventive measures to
become apparent.
The Guidance for Pesticides and Ground Water State Management Plans provides
that both a State's Generic SMP and Pesticide SMP should:
Describe the State's monitoring program for pesticides and pesticide
degradates (breakdown products or metabolites); the uses to which
monitoring will be applied; and the parties responsible for various
functions associated with monitoring. Key elements of a monitoring
program must include scope and objective, design and justification,
monitoring protocols,- quality assurance/quality control, sampling
methodology, analytical methods, and analytes.
In addition to the Generic Plan Criteria listed above, a Pesticide Plans must:
Describe the purpose of each specific monitoring protocol. For
example, SMP monitoring may be used (1) to confirm detections at
specific sites; (2) to define the extent of the problem at a specific
site; and/or (3) to evaluate the quality of ground water on an annual
basis. Each SMP would describe, for each of the three uses, the '
specific monitoring protocols to be used and who will conduct '
sampling, analysis, quality assurance/quality control, etc.
Include specific monitoring designs and justifications that address
the number of sites to be sampled, the number of samples to be
taken, the frequency of sampling, and the analytical methodology
that will be used to evaluate the samples. Quality Assurance/Quality
Control measures must be provided. Monitoring data collected by
the State should be of known and reliable quality and properly
stored for retrieval and use. (See Component 12)
Page 5-1
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TJ
Q)
(Q
(D
cn
rb
Pesticide
SMPs
Generic
SMPs
Figure 5-1. Range of Technical Tools for Developing a Monitoring Program
Type of
Monitoring
Evaluation
Monitoring
Response
Monitoring
Problem
Identification
Monitoring
Baseline
Monitoring
Monitoring Design &
Justification
Stratified sampling based on
known hydrogeology and
pesticide use characteristics of
State
Random sampling with
stratification on areas of known
presence of pesticide of interest
in ground water
Random sampling with limited
number of analyses and
sampling events
Use of existing wells and limited
number of new monitoring wells
across State
Use of existing wells and limited
number of new wells in selected
locations
Use of existing observation
wells; water supply wells; seeps
and springs; and piezometers
Sampling
Procedures
Sampling with
data collection
follow-up for
detections
Time-series
sampling
One-time
sampling
Sample
Analyses
o
I
01
Analysis for numerous
pesticides and
degradates
Use of mufti-residue
methods with qualitative
and quantitative
confirmation
Use of multi-residue
methods with qualitative
confirmation
Analyses for small
number of analytes -
Immunoassays
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Chapter 5
Include Quality Assurance/Quality Control measures as described in
Section 5.4 of this Chapter.
Describe how the placement of monitoring wells relates to the State's
priorities for protecting ground water and how the placement will
allow for evaluation of the effectiveness of prevention and response
measures. (See Component 5).
Technical considerations for developing and implementing monitoring programs
for SMPs are addressed in Sections 5.1 through 5.6. These sections provide technical
tools and options used for developing the six elements of an SMP monitoring program.
5.1 Monitoring Program Scope and Objective
The SMP monitoring program scope and objective is largely determined by
whether the State develops a generic monitoring plan or focuses on monitoring for a
specific pesticide. In the latter case, characteristics of the particular pesticide requiring
a Pesticide SMP, such as physical factors (e.g., solubility and halflife), leaching potential,
partition coefficients (Koc) and volatility, can have a significant effect on the scope of
monitoring which is necessary. For example, the scope of a monitoring program for a
pesticide that is used widely throughout a State will be considerably larger than the scope
for a pesticide whose use is limited to a small confined area of the State.
The monitoring scope and objective is influenced by the extent to which a State
has the following information:
Through implementation of the Florida Water Quality Assurance Act, the State
established a ground water quality monitoring network. The network is a cooperative effort
primarily of the Florida Department of Environmental Regulation and Federal and State
agencies. The State's monitoring objectives are threefold: (1) to establish baseline ground
water quality of major aquifers; (2) to detect and predict changes in ground water quality
resulting from land-use activities and identified sources of contamination (including
agricultural chemicals); and (3) to disseminate water quality data for use by government
entities and the public. While Florida's monitoring strategy does not focus exclusively on
agricultural chemicals, the design provides examples of baseline and response monitoring.
Contact: Florida Department of Environmental Protection, 2600 Blair Stone Roa.d,
Tallahassee, Florida 32399-2400; Telephone: (904) 488-3601. rf; /
Hydrogeologic Conditions. Monitoring of particularly sensitive
ground water may depend on knowledge concerning the location of
ground water recharge areas and sensitive or vulnerable ground
water areas as well as geologic factors such as karst areas.
Pesticide Use. Information that identifies the types and geographic
locations of pesticide uses as well as application rates help to focus
Page 5-3
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Chapter 5
pesticide-specific monitoring. Data identifying cropping patterns may
also be useful for extrapolating pesticide use.
Locations and Types of Existing Monitoring Wells. Information
about existing monitoring wells, including location (e.g., latitude and
longitude coordinates) and well design (e.g., surface seal of well and
well depth) will assist in planning monitoring programs.
The U.S. EPA Office of Research and Development (ORD), in a cooperative research
agreement -with the University of towa, is conducting a study, 'Temporal Variability of
Atrazine Contamination of Private Rural Well Water Supplies." This study:
characterizes the differences between a one-time and multiple-time
sampling study with respect to the extent of contamination, exposed
population, and health risk implications of atrazine and nitrates; and
develops statistical autocorrelation models that can be incorporated
into a multiple-sample monitoring design (i.e., temporally,
characterize a population of drinking water wells with respect to
atrazine, pesticides in general, nitrates, and other ground water
contaminants).
The study is designed to develop methodologies to appropriately monitor media for use:
in similar studies. To date, nearly all pesticides in drinking water well studies have not
been designed with an intent to use the data in an exposure and risk assessment because
they have neglected the temporal component of well water quality. For more information,
contact Matt Lorber, U.S. EPA Office of Research and Development, (202) 260-8924.
For example, a State that collects information identifying pesticide use by geographic area
and hydrogeologic conditions may be able to reduce the scope of monitoring for an
SMP. These States can target their monitoring efforts to selected areas of known
pesticide use and to areas that are sensitive or vulnerable to ground water contamination.
Ehteshami et al. (1991) developed a two-stage screening procedure for
determining pesticide contamination in Utah's ground water. The procedure's first stage
estimates a weighted average of a location's vulnerability to ground water contamination
using a hazard to ground water hydrogeological screening model (DRASTIC). The
DRASTIC model screens for vulnerable hydrogeologic sites. In the second stage, the
location of the peak concentration of organic chemicals as the chemicals move through
soil are estimated using the Chemical Movement in Soil .(CMLS) model. The CMLS model
screens pesticide/site combinations by simulating the rate of leaching of a particular
pesticide in a specific physical/chemical environment. This two-stage approach increases
the probability of locating pesticides in ground water and may reduce sampling needs
by identifying sites which have the highest risk of contamination.
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Chapter 5
Because the scope and objective of a monitoring program takes into account the
utilization of monitoring elements, the technical considerations discussed below should .
be used in developing the scope and objective element.
5.2 Monitoring Design and Justification
The principal objective of a monitoring well is to obtain representative ground water
samples. Monitoring wells must be designed and installed according to exacting
specifications to achieve the desired objectives and to maintain a high degree of
confidence in the monitoring results. Poor monitoring well design and careless well
installation procedures can significantly reduce ground water sample quality. Details of
monitoring wells designed to monitor shallow aquifers are found in Guidance for Field-
Scale Ground Water Monitoring Studies, developed by the EPA Office of Pesticide
Programs.1
A ground water monitoring network for SMPs should include both new and existing
wells. In general, the cost of developing new monitoring wells will prohibit most States
from using only new monitoring wells. The development of a monitoring well network
should identify the location and the quality of well construction to select the most
appropriate existing monitoring points. In addition, States should identify new well
locations to fill the monitoring gaps of the existing wells.
Sections 5.2.2 through 5.2.4
provide technical information on the use
of existing wells, including water-supply
wells (e.g., irrigation wells and public
water-supply wells), monitoring wells,
observation wells, and piezometers.
Section 5.2.5 discusses factors States
should consider in developing new
monitoring wells. Section 5.2.6 discusses
special considerations for ground water
monitoring in karst terrains. Section 5.2.7
discusses special considerations when
monitoring ground water in fractured
rock terrains.
5.2.1 Existing Water-Supply Wells
Water-supply wells, which include wells used for domestic, municipal, irrigation,
and industrial supply, generally are suited only to monitoring designs that permit the
withdrawal of water samples using the existing pumping system. If analytical constraints
Florida's monitoring network includes a
separate component consisting only of
private drinking-water wells. Seventy wells
per county are selected using the same
criteria developed to select existing
background and Very Intensely Studied
Area (VISA) wells. The Florida Department
of Health and Rehabilitative Services
collects ground water samples from these
supply wells and analyzes the samples for
approximately 180 parameters. The
analyses supplement data generated by the
ground water quality monitoring network
and supply general water quality data! '
1 This document is in draft form. Further information on this document may be
obtained from the EPA Office of Pesticide Programs, Environmental Fate and Effects
Division; Telephone: (703) 305-6128.
Page 5-5
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Chapter 5
require the use of special sample collection pumps or equipment, these wells may have
to be excluded from the monitoring design unless the pumping system may be
bypassed, allowing the sample to be withdrawn directly from the well column. Sampling
from water-supply wells in this way, however, is difficult, potentially time consuming, and
may inconvenience the well owner.
It is important to remember that the quality of analytical results inherently depends
on the quality of the ground water sample withdrawn from a well. Certain aspects of well
construction are essential to determine the reliability of an existing well for monitoring
purposes. In-ideal circumstances, this information may be found in well construction
reports maintained by the State offices responsible for ground water protection. The
format of well construction reports and the information they contain will vary.
5.2.2 Existing Monitoring Wells
The following criteria were used in Minnesota's ground water quality program to
select existing wells and springs for inclusion in the monitoring network (Clark and Trippier,
1977):
Sampling points are uniformly distributed with regard to the regional
flow systems;
Sampling points are selected so that baseline quality as well as
area! changes in water quality can be defined;
If possible, sampling locations or points are part of existing water
resource information systems; and
Sampling points are used frequently to ensure that ground water
samples are representative.
Attempts were made in Minnesota to locate at least one sampling point in every 1,000
square miles, or approximately one per county.
Monitoring weils are typically designed to monitor site-specific conditions. For this
reason, their well construction characteristics should be ascertained before adopting an
existing monitoring well into a regional monitoring network. It is important to collect
information on the hydrogeologic setting (ground water flow, direction, rate, and depth
to ground water), well construction, placement, and ground water discharge when
choosing existing wells as part of a monitoring scheme. Each monitoring well should be
evaluated to ensure that representative ground water samples can be collected from the
appropriate aquifer. Existing monitoring wells situated upgradient of expected
contamination sources may be suitable for use in baseline monitoring networks.
Page 5-6
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Chapter 5
The appropriate design of ground water monitoring wells is dictated by their
diameter, depth, perforated interval, and the compatibility of well construction materials
with the subsurface environment and chemical analytes. The drilling method selected and
the well installation procedures employed also influence the spatial dimensions and the
material composition of a ground water monitoring well.
>,
There are five components of a shallow well designed to monitor an unconfined
aquifer:
Screening;
Riser casing;
Filter pack;
Sealing materials; and
Cement apron and protective casing.
The typical well detail shown in Figure 5-2 does not always apply to every
hydrogeologic situation. It is intended as a general guide to design components
common in most monitoring well construction. Details on construction techniques for
monitoring wells may be found in Aller et al. (1990), Parker et al. (1990), and Nielson and
Johnson (1990).
5.2.3 Existing Observation Wells
Observation wells are generally nonpumping wells that are open or screened
throughout the thickness of the aquifer. These wells can be constructed to exacting
specifications, but are typically designed for temporary installations. Observation wells
may be constructed in an available boring drilled to obtain lithologic samples. These
wells are most suited to monitor composite water quality or head characteristics in an
aquifer. Ground water samples, however, can be collected from these wells to establish
qualitative ground water quality conditions. If properly pumped to obtain water samples
that are representative of the aquifer, these wells may also yield quantitative information
on ground water.
5.2.4 Existing Piezometers
* . i
Piezometers are generally small-diameter, nonpumping wells used for the single
purpose of measuring hydraulic-head changes in a discrete zone of an aquifer. Screen
lengths for piezometers are typically small. Ground water samples are often difficult to
obtain from a piezometer and may only represent a discrete aquifer interval.
5.2.5 Development of a New Monitoring Well .
Two major factors should be considered in developing new monitoring wells. They
are: (1) development techniques and (2) removal of influences from formation of wells.
Table 5-1 is intended as a guide to the basic well design components included on most
well construction records.
Page 5-7
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Chapter 5
Figure 5-2. Typical Monitoring Well Detail
VENTED PROTECTIVE STEEL CASING
PRIMARY FILTER PACK
(2' -3' above screen)
SECONDARY FILTER PACK
(V-21)
MONITORING WELL SCREEN
(NOT TO SCALE)
Page 5-8
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Chapter 5
Table 5-1. Basic Design Components for New Monitoring Wells
Design Components
Description
Well Diameter .
Size allows initial estimate of well casing volume that
must be purged to remove stagnant water prior to
sample collection.
Casing Material and Screen
Information
Screen length based on aquifer thickness, available
drawdown, and nature of the stratification of the
aquifer.
Water-supply wells may have multiple screened
intervals. Monitoring samples should be collected
from discrete sections of an aquifer.
Casing and screening material and the method by
which they are installed can impact the quality of
ground water samples.
Filter Pack
The filter pack zone separates the screen from the
formation material, increasing the effective hydraulic
diameter of the well.
Filter pack material (e.g., gravel pack, sand pack)
depends primarily on the textural characteristics of
the aquifer formation.
The filter pack sometimes extends several feet above
the top of the screen and consequently may bridge a
more impermeable zone in the aquifer.
When the filter pack interval is known, the sample
interval is known.
Annular and Surface Seals
Well seals are designed to prevent surface water
from moving down the annulus between the casing
and borehole walls.
Wells should be designed to provide continuous
sanitary protection.
Wells covered by an enclosure still require a surface
seal.
A frost sleeve should be installed around casings in
areas that experience average winter temperatures
below freezing. If a frost sleeve is absent in colder
areas, the structural integrity should be assessed.
A well seal is designed with respect to the mean
water table and the compatibility of the sealing clay
species with the geologic environment.
Sealing material volume in the annular space and .
methods used to emplace sealing material may
influence seal integrity.
Surface seals or aprons (of sufficient size with
sloping surfaces) should be constructed of concrete,
not cement.
Page 5-9
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Chapter 5
1. Development Techniques
Appropriate well development techniques vary from well to well. Often a variety
of techniques are used to achieve the desired results. Commonly used development
methods for monitoring wells include overpumping, backwashing, surging, bailing/
surging, jetting, airlift pumping, and air surging. These are described by Aller et al.
(1990).
2. Removal of Influences
During-final development of a monitoring well, influences from the drilling process
should be removed from the formation. Extensive time and effort are generally required
to restore "natural" flow into the well from the formation. It is most important that the
ground water withdrawn from the well be representative of the indigenous aquifer
conditions. Some coarse sedimentary aquifers and fractured rock aquifers are naturally
turbid and require less extensive development. Most unconsolidated formations,
however, are not turbid and development for the majority of aquifers should continue until
the ground water withdrawn from the well is clear and free of sediment.
5.2.6 Special Considerations for Ground Water Monitoring in Karst Terrains
Approximately 20 percent of the soils in the United States developed over soluble
carbonate type rocks, such as limestone and dolomites. Surface and subsurface features
in these areas are markedly different from those in areas underlain by other rock types.
In carbonate terrains, surface depressions develop where soluble material in the
underlying bedrock was removed by solution, causing the overlying surficial material to
collapse into the cavity beneath. These depressions, called sinks, are generally oval or
oblong in shape and when they coalesce, elongated solution valleys form. The term
karst topography is used to describe these areas of sink holes, caves, and streamless
valleys. As a generalization, almost any terrain underlain by near-surface carbonate rock
is some type or stage of karst topography.
In karst aquifers that have a well-integrated conduit system, pollutant and ground
water flow is analogous to flow in surface stream networks. Monitoring networks in karst
terrain typically utilize a combination of springs and monitoring points along cave streams.
Using dye-tracing techniques to define karst drainage patterns is the most reliable
strategy for selecting monitoring points (Quinian and Ewers, 1986), Flow in karst aquifers
may be turbulent and may occur along discrete conduits that converge and terminate as
springs. The ground water quality of a spring may therefore be representative of the
mean of the flow system. Wells can sometimes also be used to intercept and monitor the
conduits draining a ground water basin.
As outlined by Quinign and Ewers (1986), design of a ground water monitoring
network in karst areas should include:
Locating springs, streams in sinkhole bottoms, and major streams
in caves:
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Chapter 5
Preparing potentiometric surface maps;
Dye-tracing under base flow and high flow conditions to establish
connections between an area, nearby springs, and underground
streams;
Monitoring hydrogeologically connected points; and
Monitoring at least one nearby geochemically similar spring shown
by dye-tracing not connected to the site, for determining
background.
Sampling frequency should be based on hydrograph records of spring flow. Studies
have shown that complex and widely differing variations in analyte concentrations occur
in relation to storm events (Hallberg et al., 1985). Guidance for EPA-recommended
protocols for ground water monitoring in karst terrains is addressed further by Quinlan
(1989).
5.2.7 Special Considerations for Monitoring in Fractured Rock Terrains
Many scenarios of anthropogenic waste isolation include burial in unconsolidated
near-surface deposits; these wastes, however, can leach into the underlying bedrock.
Fractures in the bedrock have the capacity to transport contaminants rapidly over large
distances, and therefore, can have a great effect on ground water and surface water
resources. Prediction of fluid movement and chemical transport in fractured rock is a
complex task because of the difficulty in physically identifying and mathematically
characterizing the spatial variability of hydraulic properties of bedrock over various length
dimensions. This problem is encountered in all subsurface flow regimes, but it is more
acute in fractured rock because of extreme spatial variability and abrupt spatial changes
in hydraulic properties! These conditions make it difficult to design field experiments and
to employ interpretive methods of predicting fluid movement and chemical transport
developed for application to unconsolidated porous media.
5.3 Monitoring Protocols
This document addresses four common ground water monitoring approaches:
i
Baseline;
Problem identification;
Response; and
Evaluation.
Baseline monitoring and evaluation monitoring systems are typically used to
extrapolate information from individual monitoring points to regional ground water quality
conditions. Problem identification and response monitoring systems typically focus on
smaller geographic areas or on particular ground water quality problems. The following
Page 5-11
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Chapter 5
The basic design elements Texas' State Plan for Monitoring the Presence of Agricultural Chemicals
in Ground Water depend on exchanging information between State, federal, and agricultural
groups, as well as associated organizations involved with the management and use of pesticides.
The Texas Natural Resources Conservation Commission (TNRCC) is the lead agency for ground
water monitoring associated with the presence of agricultural chemicals.
The TNRCC used aquifer sensitivity assessments to characterize aquifer sensitivity. The TNRCC
maintains eight databases covering pesticide-use characteristics, water quality, temporal variations
in water quality, irrigation, land use, soil properties, cropping patterns, and aquifer sensitivity. The
information from the data bases is combined using a GIS to spatially relate specific parameters and
predict areas where aquifers are vulnerable to contamination from particular agricultural chemicals.
The monitoring well network in Texas consists of 8,000 existing observation welts that are
supplemented with approximately 150,000 identified private water-supply wells. The Texas Water
Development Board maintains the 8,000 observation wells, performs spring inventories, and
establishes ground water budgets. Ground water levels are monitored at least once per year.
Ground water samples are also collected, in an effort to establish baseline ground water quality and
identify potential contamination problems. These samples are analyzed for indicator parameters
including bacteria, volatile organic compounds, arsenic, and nitrates. The observation wells are
also sampled and analyzed for agricultural chemicals on three- or four-year cycles.
The TNRCC performs problem identification monitoring to substantiate suspected contamination-
problems. The TNRCC collects water samples from private water-supply wells to screen for ay
particular agricultural chemical, when requested by EPA, or when observations by private citizens
or organizations indicate the need for monitoring at a specific site.
If concentrations of an indicator parameter or pesticide are elevated, the contamination is confirmed.
by resampling the affected wells. A reconnaissance of the area around each affected well is..
conducted to identify possible contamination sources and nearby wells are monitored to assist in
identifying the contamination source. -When contamination may be attributed to a point source, the
Texas State Soil and Water Conservation Board and various agricultural groups develop a set of
voluntary pesticide handling practices.
Texas may also initiate the following options when a point source is identified: requiring permits
for the use of the agricultural chemical; continued monitoring; legal enforcement; public education;
and/or remediation.
When contamination is detected from a nonpoint source, the State may initiate the one or more of
the following response actions: revaluation of hydrogeologic data; continued monitoring;
education of product users; development of chemical-specific plans; modification of the prodtjct
label; enforcement of existing Texas Water Codes; and/or use restrictions based on site-specific
conditions.
The Texas observation well network is monitored annually to evaluate the effectiveness of
management practices relating to identified nonpoint and point sources of contamination.
Contact: Texas Natural Resources Conservation Commission, P.O. Box 13087, Capitol Station,
Austin, Texas 78711 -3087; Telephone (512) 239-1000.
Page 5-12
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Chapter 5
sections provide information on the development of monitoring plans for these four
monitoring designs.
5.3.1 Baseline Monitoring
Baseline monitoring measures ground water quality and compares it to known
background water quality standards. The background quality of the ground water in a
given aquifer is determined prior to the onset of activities that may alter the water quality.
Continued monitoring establishing trends in time or space, or both, may then continue.
Baseline monitoring designs commonly use existing wells, which are incorporated into the
overall design of a regional ground water monitoring system. This type of monitoring is
useful to determine baseline water quality conditions, to identify the existence of a ground
water contamination problem, to assess impacts of land and water use, and to plan
policies and regulations. .
Table 5-2 presents examples of baseline monitoring programs and data bases
from a number of States. The table highlights baseline studies of rural drinking water in
Iowa and Ohio, public and private water supplies in Minnesota, and water quality in
aldicarb-use areas in Florida. In addition, the table presents information on California's
Pesticides in Ground Water data base. Contact addresses of the sponsoring agencies
are also provided.
Costs of a baseline monitoring program are dependent upon the number of wells
sampled, the sample frequency, and sampling and data analysis requirements.
Considering the State ground water protection goals and targeting sensitive aquifers may
further focus the objectives of a baseline monitoring program. For example, Sanders et
at. (1983) states that because confined aquifers are less subject to surface contamination,
the water quality of these aquifers is likely to change more slowly than that of shallow
unconfined aquifers. For this reason, confined aquifers could be sampled less frequently
than shallow aquifers without compromising the monitoring designs. Thus, in balancing
costs versus information gained from targeted aquifers, variable sampling schedules can
sometimes be justified and may enable the expansion of the areal coverage of a sampling
network.
Design of Baseline Monitoring Networks
i
Baseline monitoring networks are typically regional or Statewide in scale. States
considering the use of State-wide baseline monitoring should be aware of the limitations
in using this approach to forecast over a wide area. Further, States may find it more
cost-effective to target baseline monitoring on the basis of aquifer sensitivity, ground
water vulnerability, or other priority ground water areas. Several approaches may be
used to design ambient ground water monitoring networks (Nacht, 1983). Canter et-al.
(1987) outlined three basic steps for the design and operation of a baseline monitoring
network: (1) determine which existing wells should be included in the network; (2)
determine whether new monitoring wells are needed, and if so, where they should .be
located; and (3) document data needed for handling, storage, retrieval, and reporting
Page 5-13
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Table 5-2. Examples of Baseline Monitoring Programs and Data Bases
Stale/Title
Iowa
Statewide
Rural Drinking
Water Survey"
Agency
Department of Natural
Resources, Geological
Survey Bureau
Contact Address
109 Trow Bridge Hall
Iowa City, Iowa 52242-1319
(319) 335-1585
Description
Designed to characterize all rural drinking water
wells in Iowa with emphasis on key pesticides
used in the State.
Minnesota
Department of Agriculture
Agronomy Services Division
90 West Plato Boulevard
St. Paul, Minnesota 55107
(612) 297-3994
Large-scale Statewide survey that targeted
public, private, observation, and irrigation wells.
Department of Health
Environmental Health Division
925 Delaware Street, S.E.
Minneapolis, Minnesota 55459
(612) 627-5170 (public wells)
(612) 627-5147 (private wells)
California
"Pesticides in
Ground Water
DataBase"
California Environmental
Protection Agency
Department of Pesticide
Regulation
1220 N Street
Sacramento, California 95814
(916) 324-4188
Compendium of existing studies on what is in
California's ground water and where it is.
Provides information on a number of site-
specific studies of ground water quality.
Florida
Department of Environmental
Protection, Bureau of
Drinking Water and Ground
Water Resources
2600 Blair Stone Road
Tallahassee, Florida 32399-2400
Telephone: (904) 488-3601
Two-phase, EPA-sponsored study of aldicarb in
public wells. Phase I focused on all aldicarb
use areas. Phase II focused on heaviest use
areas. Found no aldicarb in deep public wells.
Determined aldicarb did not impact deep,
protected public drinking water wells in Florida.
Ohio
Department of Agriculture
8995 East Main Street
Reynoldsburg, Ohio 43068
Telephone: (614) 866-6361
Surface and ground water State-wide study
similar to the Iowa study noted above. Focuses
on drinking water sources.
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Chapter 5
Florida's monitoring strategy utilizes a monitoring weir network established in the
mid-1980s. One component of the Florida monitoring 'strategy is the background water
quality network. This network assesses the general ground water quality of the region,
independent of known contaminated areas, '.It consists of approximately 1,700 monitoring
points that include existing wells, newly constructed monitoring wells, and protected
springs. Chemical, microbiological, and radiological analyses are combined with available
historical data to estimate baseline ground water quality. Areas where ground water
contamination has been identified are excluded from this network.
Florida monitors its ground water weil network quarterly. A smaller representative segment
of the network is monitored monthly for indicator parameters to determine changes in
ground water quality overtime. As summarized by Florida's Department of Environmental
Regulation, the background network was developed in the following phases: -
Phase I: Data collection and compilation, and location of existing wells that
could be incorporated into the network;
Phase II: Selection and drilling of initial monitoring wells;
Phase III: Initial sampling of the background network to determine
ground-water quality trends and define baseline conditions;
Phase IV: Resampling of wells found to contain significant concentrations of
one or more parameters;
Phase V: Refinement of the network through removal of redundant wells and
affected wells and drilling of additional wells where needed; and
Phase VI: Ongoing periodic resampling to define variations in ground water
quality over time. : ,
mechanisms. The general steps for the design and operation of a baseline monitoring
project are shown in Figure 5-3.
Where existing wells are not adequate to meet the spatial, needs of a baseline
network, some new wells may have to be installed. In some cases, new wells may be
needed to fill in spatial gaps or to define shallow aquifer conditions as a prelude to what
might be found in deeper aquifers. For economic reasons, it is desirable to keep the
installation of new wells to a minimum. Canter et al. (1987) report that the probability
existing wells will meet satisfactorily the needs of a baseline monitoring network
decreases as the basin size under investigation increases.
Statistical Considerations and Data Analysis
The statistical selection of sampling sites is normally guided by a prespec'rfied
random process. The two types of experimental design for sample selection are simple
random sampling and stratified random sampling. The information collected from these
sampling sites is normally used to make inferences about the target population. Cohen
et al. (1986) state that the statistical conclusions drawn from such an investigation cannot
be applied reliably to changes outside of the target population. Likewise, if wells are
Page 5-15
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Chapter 5
Figure 5-3. Baseline Monitoring
Baseline Monitoring
'Determine Background/Baseline Ground-Water Quality*
Existing wells
Monitoring wells
--O
Establish
Monitoring
Network
Consider.
Naturally occurring compounds
Pesticides
Metabolites
Consider
Well construction
Aquifer characteristics
Land use
Ground-water use
Determine
Baseline
Ground-Water Quality
Page 5-16
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Chapter 5
Baseline monitoring conducted by the Minnesota Department of Health and
Agriculture in the 1980's relied on the following factors:
Pesticides were included on the basis of information on toxicology,
environmental transport and fate, and common use in the 'State;
Wells were selected in agricultural regions of the State, and within
those regions where local or regional soils and hydrogeological
conditions made the ground water especially sensitive. Wells were
also chosen to provide areal coverage or the State's agricultural
regions and cropping patterns; and f ! ;
About 100 drinking water wells, irrigation wells, and observation
wells, five drain tiles and 400 public drinking water wells were
sampled. Each was sampled on a time-series basis. (Klaseus,
Buzicky, and Schneider, 1988).
arbitrarily included or excluded from sampling at later stages of the monitoring, the
study's statistical validity may suffer significantly.
Simple random sampling is mostly suited to narrowly designed and homogeneous
areas. The major disadvantage of simple random sampling is that it does not utilize the
relevant information available about the environment such as pesticides leaching to
ground water (Cohen et al., 1986). Such information, however, is fully utilized in a
stratified random sampling approach. The size of a stratified random sample depends
upon many factors such as the population of each stratum, the degree of precision
desired for estimates, the variance of the estimate, and the cost of obtaining a sample in
each stratum (LeMasters and Doyle, 1989). Cochran (1967) and Cohen et al. (1986)
identify three major advantages of a stratified random sampling approach. These include;
(1) the possibility of significantly lower variance for the subpopulation estimates; (2) the
ability to obtain population estimates for certain subdivisions of a target population; and
(3) elimination of the possibility that certain segments of the population may not be
sampled. Detailed information regarding the use of these sampling methods to determine
the sample size is given by Scheaffer et al. (1979).
i
Stratified sampling should only be used, however, when certain conditions are
satisfied. It may otherwise limit the usefulness of results. The National Survey of
Pesticides in Drinking Water Wells sought to identify areas of the country where drinking
water wells were most likely to contain pesticides and to oversample these areas.
Stratification was based on county-level surrogates for pesticide use and ground water
vulnerability (county-ievei DRASTIC measures). The Survey's Phase !! results indicate that
county-level stratification was ineffective. The Phase II Report lists three suggestions for
improvements:
Page 5-17
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Chapter 5
One of the components of Florida's monitoring strategy is referred to as the Very Intensely
Studied Area (VISA) Network. Florida's Department of Environmental Protection adopted
this problem identification type of monitoring to monitor areas highly susceptible to ground
water contamination. Florida identifies a VISA based on hydrogeology and land-use
information. Analytical data from VISA wells are statistically compared to like parameters
sampled from background network wells which are representative of the same segment of
an aquifer. In this way the effects of land-use practices on ground water quality are
determined. The data analysis is used to make reasonable predictions of the effects of
similar land uses in hydrogeologically similar areas. The development of the VISA Network
resulted following phases:
* Phase I: Evaluation of data to determine areas of predominant land use;
Phase II: Determination of relative susceptibility to contamination of each
potable aquifer;
Phase III: Determination of percentage of each aquifer used as a source of
potable water;
Phase IV: Selection of VISAs based on above data;
Phase V: Data collection and compilation, and selection of suitable existing
wells within each VISA;
Phase VI: Drilling of additional wells as needed; and
Phase VII: Sampling of VISA wells.
Oversample strata only if the criteria used for stratification can be
measured with sufficient accuracy to improve the survey estimates
and precision. The predictive power of the stratification variables
must be known to be high;
Stratify by pesticide use only if a good local measure of such use is
available; and
Ensure that data used for stratification include accurate data about
wells/ground water vulnerability.
5.3.2 Problem Identification Monitoring
Problem identification monitoring is monitoring to identify contamination problems
in the areas where problems are most likely to occur. The objectives are to uncover
potential pollution problems as early as possible by relating contamination levels to the
composition, quantity, and quality of a pollutant, thereby providing a basis for preventive
or corrective actions. This type of monitoring is often less costly than ambient monitoring,
since it concentrates on identifying sensitive areas and important sources of pollutants
for targeted monitoring.
Aquifer sensitivity, pesticide use, agricultural practices, and current or potential
ground water use and value are considerations in designing a problem identification
monitoring network. Problem identification monitoring for pesticides should assess
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Chapter 5
The State of California's problem identification monitoring program was used in
combination with evaluation monitoring. The California Department of Pesticide Regulation
established Pesticide Management Zones (PMZs) in areas where a pesticide was detected
in ground water or soil and contamination is attributable to legal agricultural use. Each
PMZ is pesticide-specific. The five different types are ground water monitoring are
described below.
Monitoring is conducted in the four geographical sections surrounding the
area where a pesticide has been detected in ground water. The purpose
is to determine whether the residues resulted from 'legal agricultural use or
from some other source. If the source was a legal agricultural use, the
residue falls within the scope of the Ground Water Protection Program. If
it is an illegal use, it falls within the Pesticide Enforcement Program, tf the '-;
residue is attributable to some other source, it falls under the jurisdiction of
the State Water Resources Control Board.
Monitoring in sections adjacent to PMZs is conducted to determine whether
existing PMZs should be expanded. The purpose of this type of monitoring
is to determine the extent of contamination.
Subsequently, effectiveness monitoring is conducted to determine whether
use modifications for known leachers prevents downward movement to
ground water.
Next, compliance monitoring is conducted to determine whether a known
teacher that has been banned in some or all PMZ sites is still used in these
Sites. "' '' '; .;. . . \--':.:.... v,, ..:':;..- ::^..:...;.:>;: . ;,.- .,;
Finally, legislatively mandated lists of pesticides which have the potential to
leach but that have not yet been found in ground water are monitored.
Ground water protection list monitoring is conducted to determine whether
residues of suspected leachers occur in ground water or soil under certain
conditions.
Contact: California Department of Pesticide Regulation, 1020 N Street, Sacramento,
California 95814.
whether or not a targeted pesticide has contaminated ground water. A comprehensive
discussion of the design, implementation, and statistical analysis of problem identification
or "hot spot" monitoring is presented by Gilbert (1987).
In some instances, previously collected monitoring data or aquifer sensitivity/
vulnerability assessments may indicate the potential for ground water pollution in certain
areas. States can use this information to identify likely "hot spots" for problem-
identification monitoring. Combining GIS with screening models (Chapter 3) is valuable
in identifying potentially vulnerable areas and maintaining problem identification monitoring
Page 5-19
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Chapter 5
data bases. States can use these tools to identify susceptible locations that warrant more
detailed evaluations of water-quality changes over time.
Other triggers for problem identification monitoring include (1) a change in
agricultural practices such as new cropping practices, the use of new compounds, or
new uses of existing compounds; (2) development of health concerns or new toxicologic
findings or epidemiologic evidence; and (3) identification of assessment techniques such
as previous monitoring or modeling efforts that identify areas having a vulnerable aquifer.
Table 5-3 presents examples of problem identification monitoring programs
conducted by a number of States. In Wisconsin, for example, widespread monitoring
assesses nonpoint source and point source contamination. For further information oh
these studies contact the agencies listed in Table 5-3.
The Wisconsin Department of Agriculture; Trade, and Consumer Protection began
a ground water monitoring program in 1985. In 1988, the Stale adopted health-based
ground water standards for atrazine %id alachlor. ^ program
indicated those chemicals could reach grouncl water at levels ;above the standards in
susceptible areas, no reliable(information was availableon ithe^atewide extent of the
presence of these chemicals in ground water. The State used a stratified random sample
of 534 wells on Grade A dairy farms and obtained water samples between 1988 and 1989.
The State used milk producers for several reasons. Funding limitations required a readily
available list to be used because milk producers are part of an ongoing inspection
program, the list of Grade A producers is complete and is updated regularly. Because
dairy farms are geographically distributed, results are probably representative of variations
in soil, climate, and hydrogeology in the State.
Follow-up in the Wisconsin Grade A Dairy Farm Survey included resampling when
pesticides were detected above State enforcement standards, further analysis of milk from
the farm, follow-up interviews about pesticide use and handling, interviews about
construction of the sampled well, collection of soil samples in pesticide mixing and loading
areas, collection of information about commercial applications, and collection of information
on pesticide disposal practices.
Design of Problem Identification Monitoring Networks
Problem identification monitoring networks are typically local or countywide. Many
of the general considerations outlined in Section 5.3.1 for baseline monitoring network
design are also applicable to problem identification monitoring systems. The
development of problem identification monitoring networks for ground water monitoring
programs is divided into two phases: (1) the selection of the parameters (pesticides);
and (2) the selection of site(s). Figure 5-4 depicts the steps in the development of a
problem identification monitoring network.
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Table 5-3. Examples of Problem Identification Monitoring Studies
State
Agency
Contact Address
Description
Wisconsin
Department of Natural
Resources and Water
Resources Management
101 South Webster Street
P.O. Box 7921
Madison, Wisconsin 53707
(608)267-7610
Field monitoring to assess both point source and nonpoint
source contamination.
New York
Department of Health,
Ground Water Section
225 Rabro Drive East
Hauppauge, New York 11788
(516) 853-3193
Determination of impacts on ground water of chlorothalonil
and dacthal use on turf in Suffolk County.
Connecticut
U.S. Geological Survey,
Water Resources Division
525 Ribicoff Federal Building
450 Main Street
Hartford, Connecticut 06103
Telephone: (203) 240-3060
Research to detect atrazine in monitoring network, as well as
some land-use pesticides.
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Chapter 5
Figure 5-4. Problem Identification Monitoring
Problem Identification
Monitoring
'Contamination Suspected*
Pesticide Use
Select Analytes
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Chapter 5
Problem identification monitoring may include the use of questionnaires to obtain
data about pesticide use in the area of detections and pesticide handling, mixing, and-
disposal practices. Such data may assist in identifying point-source problems and
distinguishing situations in which the presence of pesticides in ground water is due to
mishandling or improper disposal. The National Survey of Pesticides in Drinking Water
Wells, for example, collected useful information related to pesticide contamination of wells
.using questionnaires administered to homeowners, renters, well operators, and
agricultural extension agents. Data collected by telephone also worked effectively. The
Pesticide Survey results indicate, however, that respondents do not always provide
accurate data on key factors associated with the presence of pesticides or nitrates in
drinking water wells such as pesticide use, spills, and disposal. States planning to use
questionnaire data should recognize that some respondents will not be able or do not
wish to recall using the pesticide. Likewise some respondents may remember only a
generic type of pesticide (e.g., crab grass killer) for which it is impossible to determine
the active ingredient unless they have kept the container.
5.3.3 Response Monitoring
Response monitoring is typically triggered by detections of pesticides in ground
water at levels near or above a reference level (Chapter 6). Figure 5-5 depicts
considerations in the design and implementation of a response monitoring network.
Response monitoring is mainly concerned with determining the nature, quantity and
source of ground water contamination in an area where a problem exists. This type of
monitoring is usually done to evaluate the extent of a previously identified contamination
problem or to gather evidence for enforcement by State or Federal agencies.
Unlike baseline monitoring, existing wells will likely not be in proper locations or
have the proper characteristics for inclusion in a response monitoring network. Response
monitoring components include sampling other wells near the well where pesticides are
discovered and installing monitoring wells to determine whether contamination is a result
of routine field application of a pesticide. Events that may trigger response monitoring
include:
Pesticide detection at any level;
Pesticide detection at or above a specified action level; and
Qualitative detection such as field immunoassay tests or other '
environmental indicators which suggest pesticide contamination.
A discussion of response monitoring triggers is included in Chapter 6. Examples of
response monitoring programs in New York and Florida are presented in Table 5-4.
5.3.4 Evaluation Monitoring
Evaluation monitoring should be conducted to assess impacts of prevention or
response measures on ground water quality. Evaluation monitoring is typically conducted
at a regional, county, or subcounty scale. Components evaluated may include proposed
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Chapter 5
Figure 5-5. Response Monitoring
Response Monitoring
Continue Monitoring
to Evaluate
Effectiveness
of New measures
Characterize Contamination
Sources
EstaWish Monitoring
Network
Monitor
Delineate Contamination
Extent and Source(s)
Adopt More Stringent
Prevention Measures
Confirm detection
Characterize tydrogeology
Identify potential .
contamination source(s)
Remediate
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Table 5-4. Examples of Response Monitoring Studies
State
Agency
Contact Address
Description
New York
Suffolk County Health
Department
Ground Water Section
225 Rabro Drive East
Hauppauge, New York 11788
(516) 853-3193
Large-scale survey to determine extent of aldicarb
contamination in drinking water in response to confirmed
detections.
Florida
Department of Agriculture
and Conservation
Services
Capital Plaza Level 10
Tallahassee, Florida 32399-0810
Investigation of detections of aldicarb in drinking water at a
fernery site. Included the sampling of approximately 40
drinking water wells in known areas of aldicarb use and
the installation and monitoring of several monitoring wells.
The investigation also evaluated the installation and testing
of new drinking water wells.
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Chapter 5
or existing Best Management Practices (BMPs) and regulations. Evaluation monitoring
is conducted mainly to ascertain: (1) the effectiveness of BMPs, and (2) to demonstrate
the effectiveness of BMPs or remedial actions on ground water quality. The components
of an evaluation monitoring program are depicted in Figure 5-6.
Particular emphasis should be placed on defining evaluation criteria and specifying
how monitoring results will be judged (i.e., what constitutes success or failure). Other
monitoring approaches discussed in this chapter, particularly baseline monitoring and
problem identification monitoring, can provide data assessing the impact of prevention
or response measures, provided that these monitoring systems are designed to supply
all the information essential for such evaluation. Examples of evaluation monitoring
programs in Wisconsin and Florida are highlighted in Table 5-5.
Since it typically takes several years to document the effectiveness of management
practices, continued monitoring is necessary. Cumulative effectiveness monitoring can
be performed to evaluate the impact of multiple BMPs in achieving short-term and/or
long-term management standards. An example is the assessment of the impact of
no-tillage, filter strips, grassed waterways, and integrated pest management on the quality
of underlying ground water, rather than the specific effectiveness of each BMP separately.
Long-term feedback from evaluation monitoring is used to adjust management practices,
guidelines, and/or management objectives.
5.4 Quality Assurance/Quality Control
The quality of the information from any monitoring program is directly dependent
upon an organization's quality assurance and quality control program. Quality assurance
(QA) is a management function which assures that the quality of each component of a
monitoring program from planning to final report generation is known and meets quality
standards with a stated level of confidence. Quality control (QC) includes those activities
that determine and measure quality and determine whether products and results meet
specifications and established standards. In the case of monitoring programs, standards
address such factors as precision, accuracy, representativeness, completeness, and
comparability. QA ensures that the QC function is performed as specified.
There are differing views concerning what constitutes an adequate QA/QC
program. Adequacy varies with regulations and EPA programs. Under FIFRA, 'data
submitted to EPA in conjunction with a research, marketing: or use permit must be
collected under good laboratory practices (GLPs; see 40 CFR 160). Good laboratory
practices cover all aspects of data collection activities. A responsible person or unit is
generally assigned to ensure QA activities including good laboratory practices. States
that generate data for submission to EPA to register a pesticide or obtain a use permit
or an exemption, are required to establish a QA program following good laboratory
Laboratories generating data under the Safe Drinking Water Act are familiar with
QA/QC requirements of the Laboratory Certification Program. Other laboratories follow
the example of Superfund's Contract Laboratory Program in operating their QC
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Figure 5-6. Evaluation Monitoring
Chapter 5
Evaluation Monitoring
"Monitor Progress of Response to Contamination"
Select Representative
Managed/Regulated
Area
Monitor Concentrations
of Selected Analytes in
Ground Water
Revise Preventive
Action Plan
Continue Current
Preventive Action
Continue
Monitoring
Evaluate Effectiveness of
Preventive Actions
Discontinue
Monitoring
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Table 5-5. Examples of Evaluation Monitoring Studies
State
Wisconsin
Florida
Agency
Department of Natural
Resources, Water
Resources Management
Department of Agriculture
and Conservation
Services
Contact Address
101 South Webster
P.O. Box 7921
Madison, Wisconsin 53707
(608) 267-7610
3125 Conner Boulevard
Capital Plaza Level 10
Tallahassee, Florida 32399-0810
Description
Test of early 1980's program for aldicarb, which included
lower application rates, use allowed only every other year,
and temporary bans on use near wells found positive
above 10 ppb. Ten field sites were established in key use
counties. Aldicarb residues were found to persist in
ground water over the course of the 2-3 year study.
Ongoing monitoring program to ensure that Florida
restrictions on aldicarb use are fully protective of drinking-
water wells. Prograrti includes well setbacks, reduced
application rates, and registration requirements for all
users. Approximately 40-50 private drinking water wells
located near registered aldicarb users are periodically
sampled in each county where aldicarb is applied.
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Chapter 5
programs. Organizations obtaining federal grants submit QA Program Plans and/or QA
Project Plans (QAPPs) as required by 40 CFR 30.503. These Plans are reviewed by -
different EPA regions and programs using their own acceptance criteria. The guidance
specified in 40 CFR Part 30 on the preparation of these documents has been modified
by different offices within EPA for their own programs. For instance, the Office of Toxic
Substances/Exposure Evaluation Division, has developed guidance for contractors who
.submit plans to this office. This guidance emphasizes issues in statistical study design.
Section 5.4 describes the QA/QC approach for State Monitoring Plans.
In a Generic SMP, the QA program and its policies, organization, procedures, and
systems are described. A QAPP is only necessary for a Pesticide SMP. States obtaining
an EPA grant or who are familiar with the Agency's granting requirements can use the
QA Program Plan guidance for a Generic SMP and the QAPP guidance for a Pesticide
SMP to reduce the amount of time required to generate this material. The items
addressed in QA/QC plans are discussed in the following sections. The level of detail in
these plans should be proportional to the cost and significance of the monitoring efforts
they address.
5.4.1 QA/QC Plans for Generic SMPs
The QA/QC section of the Generic SMP describes an organization's QA/QC
program with a focus on its policies, objective, organization, procedures, and system.
The emphasis is on QA processes. If EPA's QA Program Plan guidance (e.g., U.S. EPA,
1980a, or U.S. EPA, 1985) is used, it should be referenced in the plan. If standard
operating procedures (SOPs) are available that address sections or items in an
appropriate manner, they may be referenced and appended. Plans must include the
following items:
QA Po//cy--The organization should state its QA policy and describe in general
terms its commitment to QA and its priority. The State should discuss the extent of its
QA program (i.e., the activities covered).
Organization and Respons/bi7/f/es--The description of the organization(s) with
pesticide and ground water management responsibilities may be in the form of a table,
chart, or narrative description. This section should list those individuals with QA
responsibility and indicate to whom each reports. This section also discusses QA
responsibilities and duties of QA personnel and management.
QA Management-The QA management section describes the processes involved
and lines of communication used in managing the QA program from inception of a
project to its completion. Flow charts may be used. Items addressed include formulation
of project objectives, development of project designs and plans including translation of
monitoring objectives into data quality indicators and criteria/objectives. This section also
describes the development of QC activities to determine whether criteria are met.
oversight activities assessing implementation of QC plans and procedures, and the
assessment of the reports of data collection efforts. The section should also include
those processes and procedures for preparing and approving plans and procedures; and
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Chapter 5
procedures to review and assess performance, data, and information; for performing
various audits; and for corrective action. The role of management, supervisory personnel,
and QA personnel should be identified, and lines of communication, and decisionmaking
should be indicated. Those making final decisions on quality should be identified. The
function of audits and their frequency should be discussed.
Routine Data Quality Criteria/Objectives-Some agencies, programs, and
laboratories have data quality acceptance criteria or policies in place which must be used
when monitoring occurs. If so, States must describe these criteria including precision of
estimates, acceptable precision and bias for analytical methods and measurements,
resampling, confirmation, and acceptable error rates for computer entries. The
information may be presented in tabular form.
Systems, Facilities, Equipment, and Services QA/QC-tf not previously covered,
States should describe the routine QA/QC processes and procedures for facilities,
equipment, and services used in monitoring programs (including such items as
automated data processing equipment, sampling, sample handling, analysis, and record
archives). Standard Operating Procedures (SOPs) can be referenced and appended to
save time. This section of the QA/QC report describes routine quality control procedures
for data entry and processing.
5.4.2 .Quality Assurance Project Plans for Pesticide SMPs
i'
The QAPP for a Pesticide SMP should contain more detail than a Generic SMP
QA/QC plan because it focuses on monitoring projects or programs for a specific
chemical. EPA guidelines are available for the development of QAPPs, (e.g., U.S. EPA,
1980b); this or other EPA guidelines previously mentioned may be used). Whatever is
used should be referenced. SOPs, publications, and manuals may be referenced and
appended to the QAPPs to address specific items. If items were already covered in the
Generic SMP States may then simply reference them. States should indicate that their
contractors plan to follow FIFRA good laboratory practices.
Most previous EPA QA efforts focused on sampling and analysis of environmental
media. Data may also be generated through the use of forms and questionnaires, such
as those used in mapping and survey activities and well construction. States should
describe the QC of these types of data gathering activities in appropriate sections in the
QAPP. Descriptions typically include project description; sampling (questionnaire
administration) procedures, sample (questionnaire) custody; internal QC checks; and
data reduction, validation, and reporting. Because EPA has not developed formal QAPP
guidance for these types of data gathering activities, States can discuss the QA/QC of
such activities in a format that facilitates its review. Previously, QAPPs have been
developed for mapping and statistics, including questionnaire administration, mapping
activities, and data on pesticide usage for the National Survey of Pesticides in Drinking
Water Wells. These documents are available from the National Technical Information
Service.
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Chapter 5
The following items should be addressed in a QAPP for a Pesticide SMP, though.
not necessarily in this order. If an item is not relevant to the project under consideration,
an explanation of why it is not must be included. If an item is covered elsewhere in the
State Monitoring Plan, States should include a reference to the appropriate section.
1. Title Page-The title page should include provisions for the signatures of
approving personnel including the organization's project officer or director, the
organization's responsible QA officer or manager (QAO or QAM), and, if applicable, the
funding organization's project officer and QA official. Indicate data and the revision
number on the title page. Inclusion of the date on subsequent pages of the document
is recommended so that revisions to the QAPP can be tracked.
2. Table of Contents-The table of contents should include an introduction,
a serial listing of the quality assurance project plan components, and a listing of
appendices required to augment the QAPP (i.e., SOPs). At the end of the table of
contents, list all individuals receiving official copies of the QAPP and any subsequent
revisions.
3. Project Descr/pf/on--This section of the QAPP should include a general
description of the project, including the experimental design. Where appropriate, include
flow diagrams, tables, and charts; dates anticipated for start and completion; intended
end use of acquired data; and statistical method or rationale for choosing sampling sites,
frequency, and procedures. Reference other sections as appropriate.
4. Project Organization and Responsibility-EPA is concerned that there will
be a distinct separation of duties between those personnel involved with the conduct or
direction of a study and those persons performing quality assurance on the same study
(52 FR 48920). The project organization and line authority should be described. If good
laboratory practices are followed, the project is required to have a single project director.
This section should list the key individuals responsible for ensuring the collection of valid
measurement data, the routine assessment of measurement systems for precision and
accuracy, and the persons with supervisory oversight.
5. QC Oby'ectiVes-QC objectives, in terms of precision, accuracy,
representativeness, comparability, and completeness, should be listed for each major
parameter and for all pollutant measurement systems. Issues such as questionnaire
administration and the overall design precision should be addressed as applicable'. The
QC objectives are actual numeric objectives when possible and should consider sources
of error such as sampling and data entry, in addition to analytical error. Numeric
objectives are usually best summarized in a tabular format - if they are available. This
section should also serve as the criteria for determining precision, accuracy,
completeness, and representativeness of the data. The criteria for establishing the
method detection limit should be presented. The effects of not meeting these objectives
on decision making and litigious actions should be discussed.
6. Sampling Procedures-For each major measurement parameter, including
all pollutant measurement systems, describe the sampling procedure used (use a
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Chapter 5
reference if jt is a standard procedure). This section of the QAPP should be consistent
with the discussion in Section 5.5.4. Information about the sampling sites should be
documented, including which sites, where they are, and how they were selected. This
section should discuss the extent to which site selection affects the data validity. This
section is very important because collection of representative data is critical to
subsequent decision making and legal defensibility of the data. In addition, the following
should be included as appropriate:
Charts, tables, diagrams, and maps;
Description of containers and reagents used;
Procedures forisample preservation, transport, and storage;
Techniques to avoid contamination of sampling equipment and
containers;
List of analytes and required sample volumes;
Sample holding time;
t,
Time considerations for sample shipment; and -;
Forms, notebooks, and procedures for recording sampling
information.
7. Sample Cusfocfy--When sample results are needed for legal purposes, it
is important that chain-of-custody procedures be followed. The sample custody section
of the QAPP should be consistent with section 5.5.4. Even if legal challenges are not
anticipated, tracking of samples is a component of good laboratory and project
management and should be addressed. If the State has SOPs for sample custody the
SOPs may be referenced and attached. If not, the following procedures should be
addressed in the QAPP.
For field sampling operations, the following should be included:
i
Documentation of procedures for acquisition, storage,
standardization, and handling of reagents and supplies;
Procedures and forms for recording the time and location of
sampling, as well as other relevant information associated with
sample;
Documentation of the specific sample preservation- method and the
integrity of the sample container;
Description of the system for sample numbering and/or identification;
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Chapter 5
Examples of pre-prepared sample labels containing all the
information necessary for effective sample tracking (if computerized,
describe the system to be used); and .
Standardized field tracking reporting forms to establish sample
custody in the field prior to shipment.
For laboratory operations, the following should be described:
Identification of the responsible party who acts as sample custodian
at the laboratory facility and is authorized to sign for incoming field
samples, obtain documents of shipment, and verify the data entered
onto the sample custody record;
Provision for a laboratory sample custody log consisting of serially
numbered standard lab-tracking report sheets; and
Specification of laboratory sample custody procedures for sample
handling, storage, and dispersion for analysis.
8. Analytical Procedures--For each measurement parameter, include a
reference to the applicable SOP or appropriate reference method, or a written description
of the analytical procedure used. Officially approved EPA procedures should be used
when available. When modifications of existing methods are used for analysis, the
modification and validation of the method should be described in this section.
9. Calibration Procedures and Frequency-It the State has SOPs for these
procedures, they may be referenced in this section. If not, the calibration procedures for
both field and laboratory equipment should be noted in the QAPP. These procedures
should include: a listing of the calibration standards; their sources(s), traceability, and
purity; references of EPA or other methods and notation of any exceptions or variances
used; a listing of accepted criteria for calibration measurement; and the schedule for
recalibration of equipment.
10. Data Reduction, Validation, and Reporf/ng-This section should briefly
describe the following for each measurement parameter. For data reduction^ the
following topics should be addressed:
Names of individuals responsible;
Summary of data reduction procedures;
Summary of statistical approach for reducing data;
Examples of data sheets;
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Chapter 5
Description of how blank and spike results will be treated in the
calculations;
Presentation of calculations and significant underlying assumptions;
Computer system used for reduction; and
Validation of software to be used.
For data validation, this section should include the following:
Names of responsible individuals;
Procedures for determining outliers and flagging data, and QC
procedures for reviewing data;
Identification of critical control points; and
Amount of planned validation, e.g., 10 percent or 20 percent.
For data reporting, the text should include the names of responsible individuals,
a flow chart of the data handling process, and identification of critical controtpoints. In
addition, the example format for the data report should be included.
11. Internal Quality Control C/?ecfcs--This section should describe and/or
reference all specific internal quality control methods to be followed. Guidance on internal
QC is available in Taylor, 1987; Taylor 1985; and U.S. EPA, 1984. Examples of items
States should consider include:
Samples (split and collocated);
Spikes and spike duplicates (field and laboratory);
Replicates;
Control chart procedures;
Blanks (field and laboratory);
Detection limit checks;
Calibration checks, standards, and devices; and
Reagent checks.
Interna! QC checks may also be applied to nonanalytical activities such as
questionnaire administration. These checks should include the use of consistent
procedures, editing, resampling a subpopulation, and debriefing interviewers. A
subsection on other activities can be added which addresses these aspects and which
further emphasizes that QA/QC applies beyond just the analytical work.
12. Performance, Systems, and Data Aucf/fs--This section describes the
periodic internal and external performance, systems, and data audits necessary to
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monitor the capability and performance of the total measurement system. This should
include a schedule of all contractor audits, which should follow FIFRA good laboratory-
practice regulations (as appropriate), and the personnel responsible for audits. If no
audits are planned, provide a justification for this decision. The schedule for any
interlaboratory performance evaluation studies should be given. Describe any data audits
to ensure that raw data and reports are consistent.
13. Specific Routine Procedures Used To Assess Data Precision, Accuracy,
and Oomp/eteness-This section describes routine procedures used to assess the
precision; accuracy, and completeness of the measurement data. These procedures
include the equations to calculate precision, accuracy, and completeness as well as
methods used to gather data for calculations.
14. Corrective AcWon-This section discusses corrective action, and includes:
trigger points; the prespecified conditions that will automatically require corrective action;
personnel who initiate, approve, implement, evaluate, and report corrective action; and
responses (what specific procedures will be used when corrective action is needed).
15. Quality Assurance Reporting Procedures-QAPPs address the need for
periodic reporting to management on the performance of measurement systems and data
quality. Requirements for reporting are specified for those projects conducted under
FIFRA good laboratory practices. If FIFRA good laboratory practices are not being
implemented, this section should include the name of the individual(s) preparing and
receiving the reports; the type of report (i.e., written, oral, interim, final); the frequency of
the reports; results of performances and data, and systems audits; significant QA
problems and the recommended solutions; and limitations on the use of the
measurement data.
5.5 Ground Water Sampling Procedures
Prior to collecting ground water samples, data quality objective (DQO) statements
must be specified to ensure that adequate quality assurance is implemented and
maintained throughout the data gathering process, and that the data generated are
reliable and valid for the intended use. To ensure that the data are of adequate quality,
DQOs for precision, accuracy, completeness, representativeness, and comparability must
be established.
i
Precision is a measure of the repeatability and replicability of sample results, and
helps define the level of effort in collecting field duplicate samples. Accuracy is a
measure of how closely observed values conform to true values in order to evaluate the
recovery of analyses such as spiked samples, matrix spikes, and matrix spike duplicates.
Completeness is a measure of the amount of information that must be collected in the
field to assure achievement of the objectives of sample collection. Representativeness
and comparability are measures of how closely the measured results reflect the actual
concentration or distribution for the chemical constituents in the sample and a measure
of whether and to what degree a data set can be compared to other data sets.
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Chapter 5
Establishing DQOs at the beginning of a monitoring program will lead to a well
developed ground water sampling effort. Prior to the collection of ground water samples,
a comprehensive sampling protocol should be developed that addresses the DQOs. This
protocol should address four major areas in implementing an effective sample collection
program:
(1) Site selection (Section 5.5.1);
(2) Sample frequency schedule (Section 5.5.2);
(3) Field sampling and measurement procedures (Section 5.5.3);
and
(4) Sample handling, custody, and transport (Section 5.5.4).
A copy of the protocol should be available to all individuals involved in ground
water sampling. Problems or variances made in the field from the ordinal protocol should
be carefully documented.2
5.5.1 Site Selection
The type of ground water source being sampled plays an important role in how
the sampling protocol is developed and the sample collection procedures. Different
sampling protocols must be used depending upon the ground water source being
monitored. The type of ground water source will play a role in the type of sample
collection equipment used and the procedures for purging the well (removing stagnant
water) as well as filling sample bottles. The three main types of ground water sources
are:
(1) water-supply and irrigation wells;
(2) monitoring wells; and
(3) seeps and springs.
Water supply and irrigation wells include wells that have been specifically
constructed as a source of water for human or animal consumption and for irrigation
purposes. These types of wells typically use mechanical pumps for obtaining water.
These wells may pump at rates less than 1 gallon per minute or at rates greater'than
1,000 gallons per minute. Others may only employ lowering a bucket down a well for
water.
2 Examples of ground water sampling protocols may be obtained from the California
Department of Pesticide Regulation, Environmental Monitoring and Pest Management
Branch, 1220 N Street, Sacramento, California 95814; and from the National Pesticide
Survey, Office of Drinking Water (4601), U.S. Environmental Protection Agency, 401 M
Street, S.W., Washington, D.C. 20406.
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Chapter 5
For the purpose of this document, monitoring wells are wells designed for the
specific purpose of sampling ground water conditions. These wells might be built with
a pump for easy sample collection or require bailing to obtain a sample.
For the purposes of this document, seeps are defined as areas where water oozes
from the subsurface and springs are defined as areas where water flows from the
subsurface onto the land surface without human assistance.
5.5.2 Sampling Frequency Schedule
The sample collection protocol should present a schedule for sampling at each
sampling point. Determining the proper sampling frequency is critical to the success and
cost-effectiveness of the sampling effort. Sampling too frequently can result in redundant
information and unnecessary expense. Infrequent sampling can result in missing
concentration trends, peak contaminant concentrations, and other temporal variabilities.
In developing a sampling frequency schedule, States should consider the economic costs
associated with the frequency in which well samples are taken.
This section provides information and guidance for determining sampling frequency
schedules that are appropriate for SMP monitoring efforts. Temporal variations in ground
water pesticide levels are discussed briefly, followed by guidance for selecting sampling
frequencies for four different ground water monitoring approaches:
(1) Baseline monitoring;
(2) Problem identification monitoring;
(3) Response monitoring; and
(4) Evaluation monitoring.
Temporal Variations of Pesticides in Ground Water
Ground water chemistry is not static, especially in shallow aquifers. Noticeable
changes in water chemistry occur in response to recharge cycles. Temporal variations
in pesticide concentrations in ground water may be affected by a variety of factors,
including:
Timing, rates, and methods of pesticide application;
Persistence or degradation of the pesticide in soil and ground water;
Pesticide leaching rate;
Variations in climate (e.g., precipitation, temperature);
Hydrogeologic factors affecting aquifer recharge and ground water
flow; and
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Chapter 5
Anthropogenic factors affecting aquifer recharge and ground water
flow (e.g., irrigation practices, well pumpage).
Recharge events (i.e., rainfall, snowmelt, and irrigation) following applications appear to
be the events most responsible for transporting pesticide residues to ground water.
Although there is substantial
evidence that temporal variability (e.g.,
long-term and seasonal) of pesticide
levels in ground water exists, this
variability has not been characterized to
the point that monitoring studies can be
designed to accurately target points in
time that sampled wells will be impacted.
USGS and EPA are researching the welte- , _ ___ . u uu .
optimum sampling frequencies as part o, £££%££%. &IS&K
EPA's Office of Research and Development
(ORD) is currently sponsoring a three year
temporal variability study of atrazine and
nitrates in ground water. This Cooperative
Agreement study between the State of Iowa
and EPA uses a portion of Iowa's Statewide
Rural Well-Water Survey (SWRL) network of
of Research and Development; Telephone:
(202) 260-8924.
a study being carried out on the
Delmarva peninsula.3 The results are
scheduled to be available in the Spring of
1994 and should prove useful for States
in designing monitoring plans. However,
almost all study designs will benefit from multiple sampling of wells in contrast to a single;
sample from a target population of wells. Wells may be sampled on a seasonal, monthly,
or more frequent basis to identify temporal changes in pesticide concentrations. As
information on seasonal variability is accrued from such efforts, the sampling schedules
may be adjusted to better target temporal variations of interest.
The following describes considerations for scheduling sampling activities for each
of the four common monitoring types described in Section 5.3.
1. Baseline Monitoring
Monitoring approaches to define baseline water quality .conditions and trends
typically involve large regions. For baseline monitoring random sampling can reduce
effects of temporal variability of individual wells over a period of one or more years to
ensure that well water samples are taken during all seasons and pesticide application
cycles. Alternatively, a baseline survey may be stratified temporally on the basis of
information on temporal variability obtained from other studies. This approach is
3 The U.S. Geological Survey Circular 1080: Are Fertilizers and Pesticides in the
Ground Water? A Case Study of the Delmarva Peninsula. Delaware. Man/land, and
Virginia. U.S. Geological Survey, 1992, provides a non-technical description of the key
findings of the NAWQA study. For more recent Information on this study, contact the
Ground Water Protection Section, Drinking Water/Ground Water Protection Branch, Water
Management Division, U.S. EPA Region 3, 841 Chestnut Building, Philadelphia, PA
10107; Telephone: (215)597-2786.
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advantageous in that it minimizes the chances of temporal biases in the study results.
If no significant temporal variability exists, either design (i.e., random or temporally
stratified) will give equivalent results.
2. Problem Identification Monitoring
Problem identification monitoring is targeted to identify problems in areas where
problems are most likely to occur. This type of monitoring focuses on site characteristics,
practices, or events most likely to result in ground water contamination.
If little is known about the influence of temporal variability on the potential for
pesticide contamination, a two-stage monitoring program may be established. In the first
stage, problem identification monitoring is scheduled on a random basis. Targeted
sampling is then conducted during the second stage to focus on particular time periods
or further define any temporal variations detected in the first stage.
In some instances, previous data collected through baseline monitoring or prior
knowledge of factors influencing temporal variability may be available. This information
can be used to schedule sample collection during the time that pesticides are most likely
to occur in ground water. In this manner, sampling efforts can be targeting temporally
as well as spatially (location).
States can use mathematical models (simple or complex) to help predict the travel
times and hence the lag between the recharge event and the potential arrival time of the
pesticide at the monitoring point. However, model predictions always carry some degree
of uncertainty; sampling events should be scheduled to bracket the most likely arrival
time. Statistical methods can also be used to schedule sampling to maximize the
probability of detecting contamination if it occurs. For example, this can be done simply
by stratifying the sampling in time according to the most likely arrival time or somewhat
likely arrival time.
3. Response Monitoring
The goal of response monitoring is to determine the nature, quantity, rate, and
source of previously detected ground water contamination. Temporal variability must be
considered when developing sampling protocols for this type of monitoring.
i
The sampling frequency and schedule for response or source monitoring should
be sufficient to determine concentration trends and their temporal variability and, if
necessary, to provide sufficient information for future predictions of contaminant migration
from the source area. Cohen et al. (1986) suggest performing sampling at the start, of
the sampling program and continuing through several temporal cycles in order to identify
temporal changes in ground water quality. Sanders et al. (1983) suggest a regular (e.g.,
monthly or weekly) sampling frequency to be adjusted as more information becomes
available. Nacht (1983) presents an analytical method for determining sampling
frequency based on the hazard rating of the contaminant.
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Chapter 5
4. Evaluation Monitoring
Evaluation monitoring is used to assess the effectiveness of an SMP or its
components. Evaluation monitoring is mainly conducted when there are issues or
concerns about the effectiveness of specific practices or about ground water quality.
To evaluate the effectiveness of a particular practice, sampling should be
scheduled both before and after the implementation of the practice and should continue
for as long as necessary to measure the full effects on ground water quality. Sampling
should be scheduled to cover all temporal variables that could affect the impacts of a
management measure on ground water quality (e.g., wet and dry weather, temperature
extremes, crop rotations, irrigation events). Other considerations relevant to scheduling
evaluation monitoring activities include: ' .
When using a paired well design, (sampling up and down gradient ; .
from an implementation site), a tolerance interval approach (e.g.,
Ward and Loftis 1986) may be used to detect sudden changes in
ground water quality;
A time trend approach (Spooner et al., 1986) may be useful in
determining the time necessary for a BMP to be effective. Variations .,
in land use, climate, and ground water hydrology are considered
when interpreting results with respect to ground water quality/BMP
relationships; and
As part of an evaluation monitoring program, soil sampling can often
provide valuable information on the migration rate and distribution of
pesticides in the soil column. Cohen et al. (1986) provide guidelines
on sampling frequency and methodology for soil sampling programs
for investigating the mechanisms of pesticide migration to ground
water.
5.5.3 Field Sampling and Measurement Procedures
Field sampling and measurement procedures include delineating, step-by-step,
sampling procedures, and sample preservation and containerization requirements. States
should consider the following five sampling and measurement procedures:
1. Selection and Decontamination of Sampling Equipment
Ground water sample collection procedures are based on the ground water
source. Selection of the correct field equipment and requirements for well purging ..are
based on the type of source sampled (i.e., water supply and irrigation well, monitoring
weii, or seeps and springs).
Choose sample collection equipment (e.g., bailers) that does not alter the ground
water sample through contact with sampler parts or through transfer and collection
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Chapter 5
operations. Sampler parts made of fluoropolymers and stainless steel are preferred (U.S.
EPA, 1986). In some cases, polypropylene materials may be preferable due to concerns-
over sorption of organic compounds to sampling equipment constructed of
fluoropolymers. Because sample collection procedures may affect the analytical results,
it is important that sampling equipment be compatible with the potential ground water
constituents. This will enable consistency between collected samples and sampling
events.
Ground water sampling equipment must be cleaned before use. The process
used to decontaminate field equipment is generally the same as that used to clean
labware. For organic constituents, sampling equipment should be washed with a
nonphosphate detergent, rinsed with tap water then distilled water, and finally rinsed with
a pesticide-grade solvent that will not interfere with the analytical method. Acetone can
be used to aid in drying and to remove any organic residue that may have remained after
washing. When decontaminating sampling equipment in the field, all rinsate solutions
should be captured for disposal away from the wellhead in accordance with State or local
regulations. Barcelona et al. (1985) suggest saving the distilled water rinsate for analysis
to check cleaning efficiency. Solvent rinsate can also be saved for the same purpose.
Tubing used for water sample collection should be dedicated to an individual
sampling location. Do not place decontaminated sampling equipment directly on the
ground. It is best to store equipment in clean sealed containers after decontamination
(e.g., plastic bags or coolers) for relocation to the well site. Handle clean equipment
using rubber laboratory gloves.
Equipment blanks are used to determine if new or reused sample equipment has
been properly decontaminated. They are prepared by passing high priority water
through a decontaminated sample collection device and transferring this water to a
sample container. Equipment blanks should be taken at the sampling site prior to sample
collection. Field blanks are used to determine if contamination is introduced from sample
collection activities. Field blanks are made by transporting high purity water to the field
and using this water to prepare aliquots for each analytical parameter group under
investigation. Field blanks collected using bailers should be decanted from the bailer into
the sample container. If nondedicated pumps are used for sample collection,
spectrographic-grade water should be pumped into a sample container to provide afield
blank.
2. Well Purging and Sample Collection
Purging stagnant water in the well column is an important first step in well-water
sampling. If the sampling pump and the purge pump are the same unit, standing water
in the well should be removed or isolated. The purging method selected for monitoring
wells ensure that stagnant water within the well casing is isolated or removed so that the
sampling apparatus contacts or collects only fresh ground water representative of the
aquifer. The chemical stability of purged water (pH, temperature, and conductance)
should be considered when sampling fresh ground water and not stagnant water in the
well casing or pump. Following well purging, sampling equipment should be flushed with
Page 5-41
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Chapter 5
at least 1 liter of representative well water prior to sample collection. The sample stream
should not be allowed to cascade into the sample bottle. Ground water should be
collected in the sample container by allowing the sample stream to gently flow along the
sides of the collection container to avoid aeration of the sample. Volatile organic
pesticide concentrations will be underestimated in aerated samples.
.*
Ground water collected should not be composited into a large vessel for
subsequent transfer into sample containers. If the sample collected from one well is split
between multiple containers and if volatile organic compounds are not among the
analytes, the sample containers should each be filled halfway using the first volumes
withdrawn from the well. The remaining volume of each sample container should be filled
adding half of each subsequent volume of ground water collected until the sample
containers are full. Samples for volatile organics should be headspace-free. .After
collection of samples for the determination of nonvolatile organic compounds, the water
level should be marked on the sample container with an indelible marker to monitor the
sample for leakage.
At the time of collection the temperature of each ground water sample should be'
noted. To minimize the possibility of sample contamination, the measurement should not:.
be made directly from the sample containers, but rather from an aliquot of the sampled.
water that can then be discarded. The following sections describe ground water
sampling methods for a number of sampling points.
3. Water-Supply and Irrigation Wells
It is best to collect the discharge water as close to the well as possible. The pump
should be allowed to purge the supply lines of stagnant water before the sample is
.collected. Monitoring pH and temperature during discharge is an effective indicator that
fresh ground water is entering the supply system. Purging techniques utilized in EPA's
National Pesticide Survey included drawing water from the wells until pH, temperature,
and conductivity stabilized (U.S. EPA, 1990). The use of a flow cell will allow monitoring
of pH and temperature during sample collection. It is important to clean the outlet of the
valve in the distribution line from which the sample will be collected. Spray from the valve
should be minimized while maintaining a gradual flow during sample collection. This
allows a greater proportion of the water stream to be sampled and lessens additional
aeration.
t
4. Monitoring Wells
It is most important, no matter what procedure is ultimately used for purging and
sampling a particular well, that the same procedure be used consistently each time the
well is sampled. For wells that monitor the phreatic .surface of the aquifer, the pump
intake should be near the phreatic (or "free water") surfacs and 5 to 10 casing volumes
should be purged to remove all the stored water in the casing or screen. Once purging
has been completed, the intake of the sampling apparatus should be situated below the
level of the purging intake. Purge water should be discharged away from the well being
sampled.
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Chapter 5
If a pump is used to collect ground water samples, the discharge should be
constant so that pulsation of the discharge, which might aerate the sample, does not'
occur. The sample should be collected directly from the discharge. To avoid degassing
the sample, discharge rates should not exceed 100 mL/min if volatile organics are to be
analyzed. If bailers are used to collect the water samples, they should not be dropped
or surged in the well. It is recommended that bailers used be equipped with a bottom
valve that will facilitate control of the collection rate from the bailer.
5. Seeps and Springs
There are several methods that may be used to sample seeps and springs. The
following methods were reported by Claussen (1982).
Remove the soil zone to allow increased flow. This will usually result
in samples that better represent the ground water; or
Install a drive point (well point) into the soft earth associated with the
seep. Use a suction pump or similar devices, if water does not flow
from the well point, to sample the ground water.
Springs:-
Insert tubing into the fissure when the spring is located on a hillside,
to allow nearly closed system sampling from the aquifer; or
Use a suction pump or a miniature submersible pump, if the spring
is located in a level area. Avoid sampling water that has been
changed by surface or near surface contaminants.
5.5.4 Sample Handling, Custody, and Transport
Proper sample handling, custody and transport procedures are important to
ensure the integrity of ground water samples. Protocols must be followed from the time
a sample is collected until the time it is received and analyzed at the laboratory; and
during any post-analysis storage. Protocols for sample handling, sample custody, and
sample transported are described below:
1. Sample Handling
After collecting a ground water sample, preserve the sample in the field using the
following sample analysis protocols (Section 5.6). Sample preservation that is appropriate
to the analytes of interest should be undertaken to minimize biological and chemical
degradation of each sample. This may include filtering and adding preservatives
appropriate for the analytical method used. Place the sample directly into insulated boxes
after collection. The main concerns in sample packing and shipping are to ensure
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Chapter 5
protection against breakage and temperature fluctuations. The following sample handling
procedures are recommended:
Ship samples, if necessary, in insulated boxes or coolers.
Wrap individual glass sample containers in plastic bubble wrap,
placed in styrofoam holders, or otherwise package to prevent
breakage during shipping.
Place ice or Gel-Cold packs in each cooler! Gel-Cold packs should
not be in direct contact with any of the glass sample containers or
the samples may freeze. Ice should be sealed in plastic bags to
prevent seepage during transport and to protect sample labels.
Deliver samples to the laboratory within 24 hours after collecting and
packing the sample.
Ship all sample tracking paperwork with the shipment and ensure
that chain-of-custody procedures are followed.
Coordination with the laboratory concerning frequency and number of samples is
important to ensure that sample holding times are not exceeded. Notify the laboratory
prior to sample collection to ensure expedited sample processing and analyzing.
2. Sample Custody
As each sample bottle is filled it should be labelled and assigned a sample tracking
number. That number should be marked on the sample container, recorded on the
chain-of-custody form, in a project notebook. Use a three-part label which includes
numbered descriptive information to be placed on the sample container. The information
placed on the sample container generally includes:
Date and time of collection;
Temperature of sample at collection;
« Well identification;
Analytes; and
Signature of sampler.
Place a security seal around the lid of each sample container. Security seals
should also be placed around coolers or outer closures on other shipping containers.
If samples are shipped to a laboratory, place a security seal around the lid of each
sample container. It is sometimes necessary to place clear adhesive tape over the seal
to protect it from excess moisture. Sample custody begins, in all cases, at the time of
sampie coiiection by placing the sample with ice in an ice chest, or other appropriate
container(s), in the presence of the field custodian. At this time the field custodian, often
the sampler, will complete a line item on the field chaih-of-custody form. This chain-of-
Page 5-44
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Chapter 5
custody form is completed by all individuals who assume responsibility for the sample(s)."
Sample custody protocols are discussed further in Section 5.4
3. Sample Transport
Samples sent by overnight carrier to the laboratory must be packaged and
shipped in compliance with current U.S. Department of Transportation and International
Air Transport Association dangerous goods regulations. Enclose sample chain-of-
custody records and any other shipping documentation in a waterproof plastic bag and
tape it to the underside of the shipment container. The container should be taped
securely shut and a security seal placed around the container.
5.6 Ground Water Sample Analysis
Monitoring plans should include protocols for sample analysis. These protocols
include the compounds to be measured, the analytical methods used to measure each
compound, and laboratory performance criteria (e.g., detection limit, quantitation limit, and
precision requirements). The performance criteria should be consistent with criteria in the
quality assurance/quality control (QA/QC) plan for the monitoring effort (see Section 5.4).
In addition, the QA/QC plan should include QC practices specified in each method used.
5.6.1 Analytic Methods
The method(s) used for sample analysis may differ between Generic SMPs and
Pesticide SMPs. Monitoring for several pesticides can sometimes be done efficiently with
multi-residue methods, allowing simultaneous measurement of a number of pesticide
compounds. Multi-residue methods are cost-effective in that they enable the analyst to
screen for a variety of pesticides with a single scan. Such multi-residue methods,
however, tend to be less precise for individual analytes and therefore tend to have higher
detection limits than methods concentrating on a single analyte.4
For individual pesticides, EPA requires pesticide registrants to provide EPA with
data on the performance of those soil and water chemistry methods used to develop
laboratory and/or field residue data (exposure, environmental fate, and ecological effects
studies) to support registration or reregistration. EPA will accept methods, both single
and multi-analyte, that meet acceptable performance criteria.
4 Recent research suggests that the frequency of herbicide detection is affected by
reporting limits. An ongoing study by the U.S.G.S. on the occurrence and distribution of
selected herbicides, atrazine metabolites, and nitrate in aquifers within 50 feet of the land
surface in the Mid-Continental United States has found a non-linear increase in atrazine
detection frequency with decreases in reporting limit. D.W. Kolfin and M.R. Burkart,
"Herbicides and Nitrate in Near-Surface Aquifers in the Mid-Continental United States,
1991" EOS, Transactions American Geophysical Union, Vol. 73, No. 43, October 27,
1992/Supplement 1992 Fall meeting, p. 229.
Page 5-45
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Chapter 5
When selecting an analytical method for a specific pesticide, several factors should
be considered. The method detection level (MDL) and practical quantitation limit (PQL)
should be appropriate for the objectives of the analysis. For example, the PQL should
be at or below the concentration of interest (e.g., the level at which specific actions will
be taken). A discussion of reporting limits for detections of pesticides in ground water
is provided in Chapter 7. The method also should be selective for the analyte of interest
and free of any interference problems from other substances likely to be present in the
sample. If the more nonselective methods are used (e.g., gas chromatography [GC] with
electron capture detection or nitrogen/phosphorous detection for sample screening), any
detections should be confirmed using a different method (e.g., a second GC column with
a different polarity).
5.6.2 EPA Methods
Because of the chemical vaTiety of pesticides and the differing needs of its
regulatory programs, the EPA has developed a variety of analytical methods for the
detection and measurement of pesticides in water samples. These methods include data
on method performance and method-specific QC practices. Analytical methods for,
pesticides have been developed for the Safe Drinking Water Act (SDWA) regulations
(500-series methods), the National Pesticide Survey (Methods 1-7), the Clean Water Act
wastewater regulations (600-series methods), the Resource Conservation and Recovery
Act hazardous waste regulations (8000-series methods), and the National Sewage Sludge
Survey (Method 1618).
The 500-series drinking water methods and the National Pesticide Survey methods
are available for the analysis of pesticides in ground water and other potential drinking
water sources. The 500-series methods are the same as National Pesticide Survey
Methods 1, 2, 3, 5, and 7. These methods employ chromatographic techniques (gas
chromatography or high-pressure liquid chromatography) coupled with sample
preparation and cleanup methods and specific detectors appropriate for the analytes of
interest. Basic information about these methods is presented in Table 5-6. Most are
multiresidue methods, and therefore are not sensitive at low levels. The 600-series and
8000-series methods are very similar to the 500-series methods and have been evaluated
for certain pesticides not included in the analyte lists for the former methods. Table 5-7
lists available EPA analytical methods for a number of pesticides.
When selecting analytic methods for baseline monitoring, consideration should be
given to reporting all concentration data, without reporting limits. The National Pesticide
Survey Phase II Report recommends that if statistical analysis of data is anticipated, "in
addition to reporting data that have satisfied both qualitative confirmation and quantitative
measurement (equivalent to data exceeding specified minimum reporting levels), a
second tier of data should be reported that have been qualitatively confirmed but that
have not been qualitatively measured at the specified levels of -precision." (U.S. EPA
1992) By reporting such results, along with sufficient information to allow users to judge
their reliability, statistical analyses that involve only the identity of the analyte are
enhanced.
Page 5-46
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Table 5-6. SDWA and National Pesticide Survey Analytical Methods for Pesticides in Ground Water
Method
Number
504
NPS Method 7
505
507
NPS Method 1
508
NPS Method 2
515.1
NPS Method 3
525
NPS Method 4
531.1
NPS Method 5
NPS Method 6
Title
1 ,2-Dibromoethane (EDB) and 1 ,2-Dibromo-3-
Chlorpropane (DBCP) in Water by Microextraction and
Gas Chromatography
Analysis of Organohatide Pesticides and Commercial
Polychlorinated Biphenyl Products in Water by
Microextraction and Gas Chromatography
Determination of Nitrogen- and Phosphorous-Containing
Pesticides in Water by Gas Chromatography with an
Electron Capture Detector
Determination of Chlorinated Pesticides in Water by Gas
Chromatography with an Electron Capture Detector
Determination of Chlorinated Acids in Water by Gas
Chromatography with an Electron Capture Detector
Determination of Pesticides in Ground water by High
Performance Liquid Chromatography with an Ultraviolet
Detector
Determination of Organic Compounds in Drinking Water
by Liquid-Solid Extraction and Capillary Column Gas
Chromatography/Mass Spectrometry
Measurement of N-Methylcarbamoxyloximes and N-
Methyl Carbamates in Water by Direct Aqueous Injection
HPLC with Post-Column Derivatization
Determination of Ethylene Thiourea (ETU) in Ground
Water by Gas Chromatography with a Nitrogen-
Phosphorous Detector
Comments
EDB and DBCP. Microextraction with hexane (35 ml
sample/2 ml hexane) Capillary column, electron
capture detector. Confirm with dissimilar column.
18 pesticides. Microextraction with hexane (35 mL
sample/2 ml hexane) Capillary column, electron
capture detector. Confirm with alternative column or
GC/MS.
39 pesticides. Liquid/liquid extraction with methylene
chloride. Capillary column. Confirm with alternate
column.
25 pesticides. Liquid/liquid extraction with methylene
chloride. Capillary column. Confirm with alternate
column.
13 pesticides. Hydrolysis with sodium hydroxide,
methylene chloride wash, liquid/liquid extraction with
ethyl ether, derivatize to esters with diazomethane.
Optional Florisil cleanup. Capillary column, confirm with
alternate column.
16+ pesticides. LSE cartridge extraction with
methylene chloride elution. Applicable to large number
of analytes; can be used for new analytes after
obtaining sufficient precision and accuracy data.
16 pesticides. Liquid/liquid extraction with methylene
chloride. Primary and confirmatlonal HPLC .columns.
10 pesticides. Uses gradient elution Chromatography
with sodium hydroxide hydrolysis after elution. Primary
and confirmational high performance liquid
Chromatography (HPLC) columns.
1 pesticide. Liquid Chromatography cleanup. Capillary
column. Confirm with alternate column.
i
T)
Q>
(Q
(0
References: U.S. EPA (1988), Munch et al. (1990).
-------
Chapter 5
Table 5-7: Analytical Methods for Selected Pesticides
Pesticide
EPA Method
Pesticide
EPA Method
Acefluorfen
Ametryn
Aldrin
Aninocarb
Atraton
Atrazine
Atrazine deethylated
Barban
Baygon
Bentazon
Bromacil
Butachlor
Butylate
Captari
Captofol
Carbaryl
Carbofenothion
Carbofuran phenol
Carboxin
Chloramben
Chlorfevinphos
Chlorneb
Chlorobenzilate(a)
Chlorothalonil
Chlorpropham
Chlorpyrifos
Coumaphos
Crotoxyphos
Cyanazine
Cycloate
2,4-DB
D-2(ethylhexyladipate)
D-2(ethylhexylphthalcites)
Dalapon
DCPA
DCPA acid metabolites
4,4'-DDD
4,4'-DDE
4,4'-DDT
515.1
507,619
505,508,525,608,8081
632
507
507
Method 4
Method 4
531.1
515.1
507
507,525
507
1618
1618
531.1
1618
Method 4
507
515.1
1618
508
508,1618
508,Method 4
507,632,
622,8141
622,8141
1618
Method 4
507
515.1,615,8151
506,525
506,525
515.1
508
515.1
508,608,8081
508,608,8081
508,608,8081
Demeton
Diallate
Diazinon(a)
Dicamba
3,5-Dichlorobenzoic acid
Dichlofenthion
Dichlorprop
Dichlorvos
Diclone
Dieldrin
Dimethoate
Dinoseb
Dioxathion
Diphenaniid
Diquat
Disulfoton
Disulfoton sulfone
Disulfoton sulfoxide
Diuron
Endosulfan 1
Endosulfan 11
Endosulfan sulfate
Endothall
Endrin aldehyde
Endrin ketone
EPN
EPIC
Ethion
Ethoprop
Ethyl azinphos
Ethyl parathion
Etridiazole
Famphur
Fenamiphos
Fenaniphos sulfone
Fenaniphos sulfoxide
Fenarimo!
Fensulfothion
Fenthion
622,8141
1618
507,622,8141
515.1,615,8151
515.1
_ 1618
515.1,615,8151
507,622,8141
1618
505,508,525,608,8081
8141
515.1,615,8151
1618,
507
549
507,622,8141
507
507
632,Method 4.
508,608,8081'
508,608,8081
508,608,8081
548
508,608,8081
1618,8081
622,8141
507
1618
507,622,8141
1618
8141
508
8141
507
Methbd 4
Method 4
507
622,8141
622,8141
Page 5-48
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Chapter 5
Table 5-7: Analytical Methods for Selected Pesticides (continued)
Pesticide
EPA Method
Pesticide
EPA Method
Fluometuron
Fluridone
Glyphosate
HCH-alpha (alpha-BHC)
HCH-beta (beta-BHC)
HCH-delta(a) (delta-BHC)
Hexazinone
Hexachlorobenzene
Hexachlorocyclopentadiene
3-Hydroxycarbofuran
5-Hydroxy Dicamba
Isodrin
3-Ketocarbofuran phenol
Leptophos
Linuron
Malathion
MCPP
MCPA
Merphos
Methiocarb
Methyl azinphos
Methyl chlorpyrifos
Methyl parathion
Methyl paraoxon
Methomyl
Metolachlor
Metribuzin DA
Mevinphos
Mexacarbate
MGK 264
Mirex
Mohnate
Monuron
Naled
Napropaniide
Neburon
Nitrofen
4-Nitrophenol
cis-Nonachlor
trans-Nonachlor
632,Method 4
507
547
508,608,8081
508,608,8081
508,608,8081
507,633
505,508,525
505,525
531.1
515.1
1618,8081
Method 4
1618,8081
632, Method 4
8141
615,8151
615,8151
507,622,8141
531.1,632
622,8141
622,8141
622,8141
507
531.1,531,632
507,525
Method 4
507,622,8141
632
507
1618,8081
507
632
622,8141
507
Method 4
1618
515.1
505
505,525
Norflurazon
Oxamyl (vydate)
PCNB
Pebulate
cis-Permethrin
trans-Permethrin
Phorate
Phosmet
Picloram
Prometon
Prometryn
Pronamide(a)
Propachlor
Propanil
Propazine
Propham
Propoxur
Ronnel
Simazine
Simeuyn
Stirofos
Sulfotepp
Sulprofos (Bolstar)
Swep
2,3,7,8-TCDD (Dioxin)
2,4,5-T
Tebuthiuron
Terbacil
Terbufos(a)
Tebuthiuron
Terbuthylazine
Terbutryn
Tetrachlorvinphos
Tokuthian (Prothiofos)
Triademefon
Trichloronate
Tricyclazole
Trifluralin
Vemolate
507
531.1
1618
507
508
- 508
8141
1618
515.1
507,619
507,619
507
508,525
Method 4
507,619
632,Method 4
531,632
622,8141
505,507,525,619,Method 1
507
507
1618,8141
622,8141
Method 4
513
515.1,615
507
507
507,622,8141
Method 4,8151
619
507,619
8141
8141
'507
622,8141
507
508,1618
507
Page 5-49
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Chapter 5
Another consideration when monitoring ground water for specific pesticides is the
possible presence of degradates of the compounds of interest. Pesticides can degrade
to compounds that may be as toxic or more toxic than the parent compounds. Detection
of these metabolites or degradation products in ground water is evidence that the parent
compounds are leaching into the environment. If possible, analytical methods should be
selected to detect degradates as well as the parent compounds. Examples of pesticide
degradates include aldicarb sulfone and aldicarb sulfoxide (from aldicarb), and disulfoton
sulfone and disulfoton sulfoxide (from disulfoton), and ethylene thiourea (ETU). If
possible, a mass balance should be performed using information on detected parent.
compounds and degradates to substantiate analytical results.
5.6.3 Immunoassay Methods
Immunoassay techniques have recently been developed for some of the triazine
pesticides (e.g., atrazine). The USGS used these methods extensively in their Midwest
Water-Quality Initiative surveys (Brown et al., 1990). Immunoassay techniques represent
immunochemical technology transferred from clinical chemistry to the analysis of
environmental samples. Each is based on a highly specific antigen-antibody reaction.
These techniques have a high sample capacity and throughput. They are especially
useful for screening samples in the field. They are sensitive, selective, precise, rapid,
cost-effective, and potentially applicable to a wide range of contaminants. A 1989
demonstration of an immunoassay technique for pentachlorophenol in water showed that:
the method requires about 30 minutes to perform, has a detection limit of about 2 ppb,
a linear dynamic range from 2 to 40 ppb, and can be used with a standard portable
spectrophotometer for standard curve generation and quantitation. The method was
comparable to GC/MS in precision and accuracy (Koglin and Poziomek, 1990).
Immunoassay techniques for a variety of chemicals, including pesticides, are currently
under development and evaluation at the Agency and elsewhere. The detection limit for
screening triazines using a colorimetric spectrophotometer ranges from 0.1 to 0.2 ppm.
The cost for screening triazines using colorimetric techniques is one-fourth to one fifth of
the cost of a GS analysis. Thurman et al. (1990) describe a successful laboratory
application of immunoassay techniques for triazine herbicide residues.
Standard QA/QC requirements (e.g., recovery, spikes, blanks) are required for
immunoassay analyses. Positive immunoassay results should be confirmed with
traditional analytical methods (e.g., GC, HPLC, and GC/MS) in order to clearly identify and
quantitate the analytes of interest. Confirmations should include pesticide residues at or
above the limit of quantitation, using traditional analytical methods. Confirmation is
necessary to reduce the impact of false positives. EPA recommends that a systematic
number of negative immunoassay water samples also be reanalyzed with traditional
analytical methods to rule out the possibility of false negatives. Samples identified -for
reanalysis should be randomly selected using standard statistical selection techniques.
A caution on the use of immunoassay techniques: Although they are simple in
operation, expertise is required in interpreting results, especially those involving
colorimetric determinations in the field. Field analysts should be familiar with the methods
Page 5-50
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Chapter 5
prior to conducting analyses, and results should be calibrated with respect to colorimetric
judgements.
5.6.4 Methods for Reducing Monitoring Costs
States can develop a cost-effective ground water monitoring program while fulfilling
the data quality objectives of the sampling effort. Developing a ground water monitoring
program requires a detailed description of the procedures for selecting sampling
locations and the step-by-step standard operating procedures for collecting and
analyzing samples. Four keys areas should be considered in determining sampling
locations and developing sampling and analysis procedures.
(1) Sampling existing wells;
(2) Selecting well sampling locations that are representative of the
aquifer rather than specific local land features;
(3) Collecting split samples; and
(4) Selecting a broad spectrum analytical technique.
Selecting existing wells (i.e., domestic, municipal, irrigation, and industrial supply
wells) can reduce sampling costs by avoiding expenses associated with drilling a new
well. In addition, careful consideration should be given to selecting wells located in areas
that are representative of the aquifer rather than site-specific land features. Selecting
wells based on geologic and aquifer characteristics reduces the number of wells that
have to be installed and monitored compared to wells that may only characterize local
land features (e.g., pesticide loading/unloading areas). .
The U.S. EPA Office of Research and Development (6RD) in a cooperative research
agreement with the University of Iowa is conducting a study, Temporal Variability of
Atrazine Contamination of Private Rural Well Water Supplies," that provides cost-effective
management techniques for conducting a water quality monitoring program. The
techniques considered by this study include making owners responsible for taking samples
and using immunoassay techniques to screen for contamination. By implementing these
cost cutting techniques, samples collected from the same well over a period of time can
be used to adequately characterize the extent and degree of human risk exposure. For
more information, contact Matt Lorber, U.S. EPA Office of Research arid Development,
(202) 260-8924.
Collecting split samples can also reduce monitoring costs. Split samples, which
are allocated by dividing a field sample into two separate bottles can permit independent
analysis (e.g., confirmation of detection) of the sample at a latter date without incurring
additional field sampling costs. Finally, selecting an approved EPA multi-residue method
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Chapter 5
can reduce analytical preparation and extraction costs compared to a pesticide-specific
analytical procedure.
5.7 References
Aller, L, T.W. Bennett, G. Hackett, R.J. Petty, J.H. Lehr, H. Sedoris, D.M. Nielsen, and
J.E. Denne. 1990. Handbook of Suggested Practices for the Design and Installation of
Ground Water Monitoring Wells. National Water Well Association, Dublin, OH. NTIS
PB90-159807. 398pp.
Barcelona, MJ. 1985. Illinois State Water Survey. Champaign, IL SWS Contract Report
374. NTIS PB86-137304. 93pp.
Brown, D.E., M.T. Meyer, M.L Pomes, E.M. Thurman, and D.A. Goojsby. .1990.
'Temporal variations of trizone and cfiloroacetanilide herbicide concentrations in selected
streams in the Midwestern United States, April-August 1990." Abstract submitted for
publication in EOS and for presentation at the American Geophysical Union Fall Meeting,
San Francisco, CA.
Canter, L.W., R.C. Knox, and D.M. Fairchild. 1987. Ground Water Quality Protection.
Chelsea, Michigan: Lewis Publishers, Inc.
Clark, T.P., and Trippler. 1977. "Design and Operation of an Ambient Ground Water
Quality Monitoring Program for Minnesota." NWWA Symposium, National Water Well
Association. Worthington, OH.
Claussen, H.C. 1982. Guidelines and Techniques for Obtaining Water Samples that
Accurately Represent the Water Quality of an Aquifer. U.S. Geological Survey, Water
Resources Division.
Cochran, W.G. 1967. Sampling Techniques. Second Edition. New York, NY: John
Wiley and Sons, Inc. .
Cohen, S.Z., S.M. Creeger, R.F. Carsel, and C.G. Enfield. 1984. In: Treatment and
Disposal of Pesticide Wastes. Editors: R.F. Krueder, and J.N. Seiber. American
Chemical Society. Washington, D.C. ACS Symposium Series No. 259:297-325.
Cohen, S.Z., C. Eiden, and M.N. Lorber. 1986. "Monitoring Ground Water for Pesticides."
In: Evaluation of Pesticides in Ground Water. Editors: Garner, W.Y., R.C. Honeycuit,
and H.N. Nigg. American Chemical Society, pp. 170-196.
Ehteshami, M., R.C. Peralta, H. Eisele, H. Deer, and T. Tindall. 1991. "Assessing
Pesticide Contamination to Ground Water: A Rapid Approach." Ground Water.
29:862-868.
Gilbert, R.O. 1987. Statistical Methods for Environmental Poiluiion Monitoring. N.Y.: V?p.
Nostrand Reinhold. 320 pp.
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Chapter 5
Goolsby, D.A., E.M. Thurman, M.L. Clark, M.L Pomes. 1990. "Immunassays for Trace
Chemicals Analysis." In: Monitoring Toxic Chemicals in Humans. Food, and the-
Environment. Editors: Vanderlaan, M., LH. Stanker, B.E. Watkins, and D.W. Roberts.
American Chemical Society. ACS Symposium Series No. 450. 13 pp.
Hallberg, G.R., R.D. Libra, and B.E. Hoyer. 1985. "Nonpoint Source'Contamination of
.Ground Water in Karst Carbonate Aquifers in Iowa." In: Perspectives on Nonooint
Source Pollution. U.S. Environmental Protection Agency. EPA 440/5-85-001. pp. 109-
114.
Mines, J.W., W. Haugan, D. DeLuca. 1990. Minnesota Department of Agriculture Water
Quality Monitoring: Biennial Report. Minnesota Department of Agriculture. 30 pp.
Kearl, P.M., N.E. Korte, and T.A. Cronk. 1991. "Suggested Modifications to Ground
Water Sampling Procedures Based on Observations from the Colloidal Borescope."
Environ. Sci. Techol., 1991:25. 3pp.
Klaseus, T.G., G. Buzicky, and E. Schneider. 1988. Pesticides and Groundwater:
Surveys of Selected Minnesota Wells. Minnesota Department of Health and Minnesota
Department of Agriculture. 95 pp.
Klaseus, T.G., and J. Mines. 1988. Pesticides and Groundwater: A Survey of Selected
Private Wells in Minnesota. Minnesota Department of Health. 76 pp.
Lemasters, G. and D.J. Doyle. 1989. Grade A Dairy Farm Well Quality Survey. Madison,
Wl: Wisconsin Department of Agriculture, Trade and Consumer Protection and Wisconsin
Agricultural Statistics Service.
Nacht, S.J. 1983. "Monitoring Sampling Protocol Considerations." Groundwater
Monitoring Review.
Nielson, D.M. and A.I. Johnson. 1990. Ground Water and Vadose Zone Monitoring.
ASTM, Philadelphia, PA. 313 pp.
Parker, L.V., A.D. Hewitt, and T.F. Jenkins. 1990. "Influence of Casing Materials on
Trace-Level Chemicals in Well Water." Ground Water Monitoring Review 10(2): 146-155.
Pomes, M.L. and E.M. Thurman. 1990. "Comparison of microtitre pface immunoassay
(ELISA) and GC/MS for herbicides in stormflow samples." Abstract submitted for
publication in EOS and presented at the San Francisco American Geophysical Union
1990 Fall Meeting.
Quinlan, J.F. and R.O. Ewers. 1986. "Reliable Monitoring in Karst Terrains: It can be
done, but not by an EPA-approved method." Groundwater Monitoring Review. National
Water Well Association, pp. 4-6.
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Chapter 5
Quinlan, J.F. 1989. Ground Water Monitoring in Karst Terrains: Recommended
Protocols and Implicit Assumptions. EPA Inter-Agency Unpublished Document. 79 pp.
Quinlan, J.F. and R.O. Ewers. 1985. "Ground Water Flow in Limestone Terrains:
Strategy Rationale and Procedure for Reliable, Efficient Monitoring of Ground Water
Quality in Karst Areas. Proceedings of Fifth National Symposium and Exposition on
Aquifer Restoration, Columbus, OH. pp. 197-234.
Rhode Island Department of Environmental Management. 1990. Ground Water Section.
Rhode Island Private Well Survey Final Report.
Rogers, C. April, 1991. Personal Communication. Texas Water Commission.
Sanders, T.G., R.C. Ward, J, C. Loftis, T.D. Steele, D.D. Adrian, and V. Yevjevich. 1983.
Design of Networks for Monitoring Water Quality. Littleton, CO: Water Resources
Publications.
Schaeffer, R.L, W. Mendenhall, and L Ott. 1979. Elementary Survey Sampling. Second
edition. North Scituate, MA: Duxbury Press.
Spooner, J.C., C.A. Jamieson, R.P. Mass, S.A. Dressing, M.D. Smolen, and F.J. Humenik.
1986. Rural Clean Water Program Status Report on the CM&E Projects
1985 - Supplement Report: Analysis Methods. Biological and Agricultural Engineering
Department, N.C. State University, Raleigh.
Taylor, John K. 1987. Quality Assurance of Chemical Measurements. Chelsea, Ml.
Lewis Publishers, Inc.
Taylor, John K. 1985. Principles of Quality Assurance of Chemical Measurements. U.S.
Department of Commerce, National Bureau of Standards. NTIS PB 85-177947.
Thornhill, J.T. 1989. Accuracy of Depth to Water Measurements. U.S. EPA. Roberts.
Kerr Environmental Research Laboratory, Ada, OK. EPA 540/4-89/002.
Thurman et al. 1990. "Enzyme-Linked Immunosorbent Assay Compared with Gas
Chromatography/Mass Spectrometry for the Determination of Triazine Herbicides in
Water." Analytical Chemistry. 62(18):2043-2048.
Thurman, E.M., D.A. Goolsby, M.T. Meyer, and D.W. Kolpin. 1991. Herbicides in Surface
Waters of the Midwestern United States: The Effect of Spring Flush. U.S. Geological
Survey, Kansas. 3 pp. .
U.S. EPA. 1991. Ground Water Handbook (revised^. Volume II: Methodology. U.S.
EPA-ORD. Cincinnati, OH. EPA 625/6-90/016b.
U.S. EPA. 1991. Handbook of Suggested Practices for ths Design and Installation of
Ground Water Monitoring Wells. U.S. EPA-ORD. Cincinnati, OH. EPA 600/4-8a/034.
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Unapxer o
U.S. EPA. 1990. National Survey of Pesticides in Drinking Water Wells - Phase I Report.
EPA 570/19-90-015. NTIS PB91-125765.
U.S. EPA. 1987. Ground Water Handbook. U.S. EPA-ORD. Cincinnati, OH. EPA
625/6-87/016.
U.S. EPA, Office of Waste Programs Enforcement, Office of Solid Waste and Emergency
Response. 1986. RCRA Ground Water Monitoring Technical Enforcement Guidance
Document. OSWER-99501.1. 317pp.
U.S. EPA. 1986. RCRA Ground Water Monitoring: Technical Enforcement Guidance
Document.
U.S. EPA, Office of Research and Development, Quality Assurance Management Staff.
1985. Guidelines and Specifications for Preparing Quality Assurance Program Plans for
National Program Offices. ORD Headquarters, and ORD Laboratories.
U.S. EPA. 1985. Practical Guide for Ground Water Sampling. U.S. EPA-ORD.
Cincinnati, OH. EPA 600/2-85/104.
U.S. EPA, Office of Research and Development, Quality Assurance Management Staff.
1984. "Chapter 5: Calculation of Precision, Bias, and Method Detection Limit for
Chemical and Physical Measurements."
U.S. EPA. 1981. Manual of Ground Water Sampling Procedures. EPA 600/2-81/160.
National Water Well Association (NWWA), Dublin, OH or-National Technical Information
Service (NTIS), Springfield, VA.
U.S. EPA, Office of Research and Development, Quality Assurance Management Staff.
1980a. Guidelines and Specifications for Preparing Quality Assurance Program Plans.
QAMS-004/80.
U.S. EPA, Office of Research and Development, Quality Assurance Management Staff.
1980b. Interim Guidelines and Specifications for Preparing Quality Assurance Project
Plans. QAMS-005/80.
U.S. EPA. 1992. National Pesticide Survey Quality Assurance Plans:
Battelle - Columbus. February. Quality Assurance Project Plan for the
National Pesticide Survey of Drinking Water Wells: Analytical Method 6 --
Ethvlene thiourea. EPA 810/B-92/012.
Clean Harbors Incorporated. February. Quality Assurance Project Plan for
the National Pesticide Survey of Drinking Water Wells: Analytical Method
2 -- Chlorinated Pesticides. EPA 810/B-92/003.
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Chapter 5
Environmental Chemistry Laboratory of the Office of Pesticide Programs.
February. Quality Assurance Project Plan for the National Pesticide Survey
of Drinking Water Wells: Analytical Method 1. EPA 810/B-92/010.
Environmental Chemistry Section of the Office of Pesticide Programs.
February. Quality Assurance Project Plan for the National Pesticide Survey
of Drinking Water Wells: Analytical Method 3. EPA 810/B-92/011.
ES&E. February. Quality Assurance Project Plan for the National Pesticide
Survey of Drinking Water Wells: Analytical Method 5 -- Methyl carbamates.
EPA810/B-92/005. .
ES&E. February. Quality Assurance Project Plan for the National Pesticide
Survey of Drinking Water Wells: Analytical Method 7 -- Fumiaants. EPA
810/B-92/007.
ETU, Environmental Chemistry Section of the Office of Pesticide Programs.
February. Quality Assurance Project Plan for the National Pesticide Survey
of Drinking Water Wells: Analytical Method 6. EPA 810/B-92/006.
ICF Incorporated. February. Quality Assurance Project Plan for the
National Pesticide Survey of Drinking Water Wells: Hvdrogeologic
Characterization and Second-Stage Stratification Activities. EPA 810/B-
92/013.
ICF Incorporated. February. Quality Assurance Project Plan for the
National Pesticide Survey of Drinking Water Wells: Well Sampling. Data
Collection, and Processing. EPA 810/B-92/014.
ICF Incorporated and Westat Incorporated. February. Quality Assurance
Project Plan for the National Pesticide Survey of Drinking Water Wells:
Survey Statistics. Data Collection and Processing. EPA 810/B-92/015.
Montgomery Laboratories. February. Quality Assurance Project Plan for
the National Pesticide Survey of Drinking Water Wells: Analytical Method
1 -- Phosphorus Pesticides and Analytical Method 3 - Chlorinated Acid
Herbicides. EPA 810/B-92/002.
Montgomery Laboratories. February. Quality Assurance Project Plan for
the National Pesticide Survey of Drinking Water Wells: Analytical Method
9 -- Nitrate and Nitrite. EPA 810/B-92/008.
Quality Assurance Program Plan for the National Pesticide Survey of
Drinking Water Ws!!s. February. EPA 810/B-92/001.
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unap'ier o
Radian Corporation. February. Quality Assurance Project Plan for the
National Pesticide Survey of Drinking Water Wells: Analytical Method 4 --
Carbamates. EPA 810/B-92/004.
Technical Support Division, Office of Drinking Water and Risk Reduction
Engineering Lab, Office of Research and Development. February. Quality
Assurance Project Plan for the National Pesticide Survey of Drinking Water
Wells: Referee Analyses for Method 2 -- Oraanochlorine Pesticides. Method
4 -- Carbamates. Method 5 -- Methvlcarbamates. Method 7 -- Fumiaants.
and Method 9 -- Nitrate/Nitrite. EPA 810/B-92/009.
Ward, R.C. and J. C. Loftis. 1986. "Establishing Statistical Design Criteria for Water
Quality Monitoring Systems: Review and Synthesis." Water Resources Bulletin
22(5):759-767.
Wisconsin Department of Agriculture, Trade, and Consumer Protection and Wisconsin
Agricultural Statistics Service. 1989. Wisconsin Grade A Dairy Farm Well Water Quality
Survey. 36 pp.
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Chapter 6
Chapter 6
Response Plan
EPA's priorities for responding to ground water contamination'by pesticides are
to limit the risks of adverse effects to human health first and then to restore currently used
and reasonably expected drinking water supplies and ground water closely hydrologically
connected to surface waters, whenever such restorations are practicable and attainable.
In making remedial decisions, a realistic approach to restoration should be taken based
on actual and reasonably expected uses of the resource as well as social and economic
values. This chapter provides a framework for addressing the SMP component involving
response to the detection of pesticides in ground water. Many different responses to
subsurface contamination are possible. The appropriate response for a given incident
of contamination is usually a function of the level and source of contamination, a State's
ground water protection philosophy, and the use and value of the ground water that has
been contaminated. Based on a determination of the cause of contamination and the
risks associated with the contamination, technical and management information may be
combined to determine how to prevent future occurrences of a similar nature.
The Guidance for Pesticides and Ground Water State Management Plans provides
that both a Generic and Pesticide State Management Plan should:
Describe the actions the State will take if a pesticide has exceeded
or is expected to exceed reference points in ground water. When a
pesticide level in ground water approaches, reaches, or exceeds an
MCL or other reference point as a result of normal agricultural use,
an aggressive stance should be taken, including the possibility of
prohibiting further use of the pesticide in the affected areas.
Detections below reference points should also trigger actions to
prevent contamination with the potential to pose risks to human
health and the environment (See Component 7.) The State's
response section of its SMP may overlap with its prevention section.
However, it must at a minimum pick up where the prevention section
left off.
Describe the steps that will be taken, and who will be responsible '
for: (1) identifying, if possible, the source of contamination,
(2) ascertaining whether contamination resulted from normal use in
accordance with label directions and other requirements, or from
misuse or accident, and (3) determining whether the detection was
found in a vulnerable or non-vulnerable area, which may be critical
in establishing how the State assesses leaching potential
(Component 5). In cases of misuse, enforcement actions should be
pursued.
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Chapter 6
Describe the State's response policy regarding contaminated ground
water that is used as a source of drinking water. The SMP must
discuss generally what steps will be taken to protect public health.
The State may need to provide or fund interim sources of drinking
water if necessary. If the contamination constitutes a violation of the
SDWA regulations1 for which the Public Water System is
responsible, these detections should be referred for enforcement
action under authority of SDWA. The State will also need to
determine actions for responding to contamination in private wells,
including notifying well owners.
The requirements listed above should be presented in the form of a
general corrective response scheme, including timeframe(s) and
identification of the agencies responsible for various activities,
thereby illustrating the State's capacity for timely, coordinated
response to contamination.
In addition to the Generic Plan Criteria listed above, a Pesticide Plan must:
Indicate the levels (at the MCL or other reference point, or above
these standards) at which the State intends to take or require
remedial action to reduce contamination of currently used or
reasonably expected sources of drinking water. The SMP must also
indicate what specific steps the State will take, and the timeframe in
which it will act, to initiate measures commensurate with
contamination levels to reduce the possibility of further contamination
toward significant health or environmental concern (i.e., levels at the
reference point).
The response measures presented in this chapter are ideas that States should
evaluate and implement as appropriate given the specific goals and conditions in each
State and the guidelines presented in Appendix A. Examples are provided to encourage
States that do not have a response plan in place to seek information from other States
and develop their own most appropriate response strategies. This chapter discusses
several aspects of response plans, including:
» How the response, monitoring, and prevention components of an
SMP are related;
/
« An overview of selected response measures for ground water
contamination;
1 A violation under the SDWA relates to the average contaminant concentration over
four consecutive quarters or to a single sample that is greater than 4 times the MCL
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Chapter 6
How to evaluate the causes of pesticide contamination of ground
water; and
A framework for using reference points or action levels in
implementing response measures.
6.1 Relation of Response, Monitoring, and Prevention Components of
anSMP
Response measures overlap monitoring and preventive measures at the point that
pesticide contamination is found in ground water. If a State discovers that contamination
of ground water has occurred, then appropriate monitoring is needed (see Chapter 5).
A State should also implement additional, more stringent preventive measures to prevent
contamination (See Chapter 4). Evaluation monitoring should then be continued to
assess the impacts of preventive measures on ground water quality (See Chapter 5).
Following detections of pesticides in ground water, appropriate response measures
might include:
Providing alternate safe sources of drinking water;
Increasing monitoring and other activities to determine and evaluate
the causes of contamination and the effectiveness of prevention or
response actions;
Implementing more stringent preventive measures, including
regulatory and enforcement approaches, to eliminate the threat of
further ground water contamination; and
Remediating contaminated ground water.
6.2 Response Measures
Any confirmed detection of a pesticide in ground water should trigger a response
action. Appropriate response plans depend on the level of contamination confirmed in
ground water in relation to established reference points, the State's ground .water
protection philosophy, and the use and value of the ground water resource as well as
social and economic values. Response measures might include:
Implementing increasingly stringent preventive measures, including
pesticide-use limitations or restrictions;
Treating contaminated drinking water supplies; and
Remediating the aquifer.
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Chapter 6
6.2.1 Implementation of Increasingly Stringent Preventive Measures
SMPs should emphasize prevention of adverse effects to human health and
protection of the environmental integrity of ground water resources. Detections of
pesticides in ground water serve as a means to define failure of preventive measures
already taken.
Both Generic and Pesticide SMPs should consider contingency response
measures for increasingly stringent prevention actions when contamination levels rise.
Such measures might include the following:
Revising pesticide management preventive measures;
Implementing site-specific use restrictions;
Implementing use restrictions for large, vulnerable areas; and
Implementing statewide use restrictions or prohibition.
Before a State reassesses and revises its preventive measures, the State should
consider investigating the cause(s) of a pesticide contamination incident. In particular,
an investigation should seek to determine if contamination occurred as a result of normal,
registered use of the pesticide or from misuse. If the contamination occurred as a result
of normal, registered use, then the State should reconsider the preventive component of
its SMP. Revisions to the SMP's prevention component should be tailored to the causes
and level of contamination.
Limitations on pesticide use can be an effective tool to protect against the adverse
effects of pesticide contamination of ground water. As discussed in Chapter 6, use
limitation can apply both to application techniques and to geographic settings. If
pesticides are found in ground water, actions should be taken to diagnose the cause of
the particular detection to determine whether any further regulatory management
approaches are needed. The most stringent and most protective preventive measure is
a moratorium on pesticide use in a particular area of the State that .is susceptible to
ground water contamination.
6.2.2 Water Supply Treatment and Other Response Mechanisms
In addition to preventing pesticide contamination of ground water with the potential
to pose risks to human health and the environment, the SMP should discuss the
situations in which a State will select water supply treatment as a response measure.
This decision is typically made based on the use and value of the ground water resource
and the treatment techniques available (i.e. bottled water or connection to an
uncontaminated water system). A State should also consider the use of alternative water
supplies, depending on the risks posed by the pesticide contamination.
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Chapter 6
The use of alternative water supplies to respond to contamination incidents"
includes connecting to a neighboring water supply system, hauling water from a
neighboring water supply system via tank trucks, and distributing bottled water. The use
of alternative water supplies may be a short-term solution. Some communities, however,
may need to establish permanent connections with neighboring water suppliers
depending on the severity of the contamination.
The most common short term response to contaminated private drinking water
supplies uses "point-of-use" (at the tap) or "point-of-entry" (entry point to the residence)
water-supply treatment. Typically, this approach involves the installation and maintenance
of filters that will reduce contaminant concentrations down to acceptable levels. This
alternative provides treatment of the water prior to use or consumption, but does not
correct the source of contamination. That is, water supply treatment does not address
the environmental impacts of pesticide contamination.
Common municipal treatment processes include disinfection, filtration, coagulation,
sedimentation, adsorption, blending, ion exchange, gas stripping, and membrane
separation. The point-of-use activated carbon adsorption process is the most common
treatment method used in individual domestic households to remove organic ground
water contaminants. The efficacy and design of any water supply treatment system to
remove pesticide residues should include a treatability study.
All water supply treatment schemes require maintenance. Failure to provide
adequate maintenance will lead to incomplete removal of contaminants in the treatment
system. Common treatment methods, such as activated carbon units, can provide an
environment for microorganisms to colonize and grow. If such bacteria grow and are not
removed by subsequent treatment (e.g., chlorination), an additional risk may be
introduced by using the treatment system.
The State of Florida has issued policies defining action levels for filter installation
and removal. In most cases, the registrants of the pesticides detected in Florida's ground
water are responsible for implementing the filter programs. For additional .information on
the registrant-sponsored filter programs in Florida, contact "the. Florida Department of
Environmental Protection, 2600 Blair Stone Road, Tallahassee, Florida 32399-2400;
Telephone: (904)488-3601.
i
Registrant-sponsored filter programs have also been undertaken in New York,
Maine, and Wisconsin. In some cases, the registrants have established the action levels
at which filters should be installed or may safely be removed. State-specific legislation
should be examined to identify the responsibilities of registrants, pesticide users, and State
agencies in implementing and administering filter programs. '
Page 6-5
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Chapter 6
The City of Fresno, California is implementing a Water Quality Improvement Plan
to address 1,2-dibromo-3-chloropropane (DBCP) contamination of the principal water
supply. The entire water supply for the City of Fresno is derived from 267 wells that tap
an EPA-designated sole-source aquifer. Seventy-one (71) of these weils have exhibited
detectable levels of DBCP, and 25 were dosed due to DBCP contamination that exceeds
the MCL. The Water Quality Improvement Plan authorized direct DBCP mitigation
measures, including wellhead treatment ^projects, :well rehabilitation projects, the
construction of replacement wells, and the construction of water main extensions to
provide clean water supplies. To date, the City has expended over $50 million to address
ground water contamination problems associated with DBCP. Because of DBCP's half life
and the persistent migration of this contaminant into aquifer areas that supply the city's
drinking water, the City of Fresno estimates that mitigation and litigation costs will exceed
$200 million dollars by the year 2000. For additional information, contact Martin Mclntyre,
City of Fresno Water Division, 1910 East University, Fresno, CA 93703; Telephone:
(209)498-4126. :
6.2.3 Remediation
The SMP should discuss the situations in which remediation will be selected as a
response measure, and the remediation techniques that will be considered. In some:
instances, particularly those where ground water contamination is attributable to point-
source releases of pesticides (e.g., releases from pesticide storage sites), containment
measures and/or subsurface restoration techniques may be appropriate. The following
sections provide an overview of containment and restoration measures that may be
pertinent in cases of high-level, localized pesticide contamination of ground water.
The California Regional Water Quality Control Board conducted a study of
alternative mitigation strategies for contaminated ground water in the San Joaquin Valley.
More than 112 public water-supply wells in four counties are reported to be shut down due
to DBCP concentrations that exceed the MCL of 0.2 ppb. The preliminary results of the
study include the development of BMPs to address the mitigation of DBCP contamination
of ground water, an economic evaluation of DBCP mitigation alternatives, an evaluation of
the feasibility of implementing a ground water extraction/recharge procedure to reduce
DBCP concentrations in the San Joaquin Valley, and a viable plan for DBCP mitigation in
the area. For additional information, contact the California Regional Water Quality Control
Board, 3443 Routine Road, Suite A, Sacramento, CA S5827; Telephone: (SIS) 255-2
Vertical Flow Source Barriers
For relatively small source areas (point sources), preventing the vertical recharge
of water would tend to isolate residual contamination in the unsaturated zone. This could
be accomplished by placing an impermeable barrier on the surface, which couid be either
a natural clay material or a synthetic liner. The cost of this containment method would
generally restrict such practices to small contaminated areas.
Page 6-6
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Chapter 6
Hydraulic Withdrawals
Hydraulic withdrawals are commonly used in response to point source
contamination. Two common types of hydraulic withdrawals have application for
pesticide contamination: abstraction wells and drains. Abstraction wells are sometimes
used to control contaminant migration and as a method to remediate contaminated
aquifers (Keely, 1989; Mercer et al., 1990). The notion is simple: by placing a well in a
contaminated region and pumping water out of the well, ground water flows in every
direction toward the well. If the well, or system of wells, pumps at a sufficient rate, a
contaminant plume can be contained.
Hydraulic withdrawals are sometimes achieved through the use of drains. In
drainage systems, a drain is placed at the boundary of a contaminated region at a depth
sufficient to ensure the capture of all contaminated water. This differs from a well
containment system in that water is" removed along a line rather than at a point. The
practical significance of this difference is that contaminant containment can often be
achieved with less total water being removed from a system using a drain than an
abstraction well or series of abstraction wells. This leads to a reduction in the volume of
contaminated water that requires treatment or disposal.
Physical Removal and Disposal
Physical removal and disposal of contaminated source materials is required under
unusual circumstances. Typically, the source of contamination may be isolated to a small
area. Such measures are typically very expensive and should be used only as a last
resort. The high cost of physical source removal and disposal enforces practical limits
on the method to relatively small (point source), highly contaminated regions that are
affected by solutes that are relatively resistant to degradation. This would not be a
feasible alternative for nonpoint source pesticide contamination incidents.
Enhanced Degradation
The rate at which pesticides degrade in the subsurface environment depends on
many factors. In response to subsurface contamination, a pesticide's propensity to
degrade may be exploited in the source area to limit the solute mass that will reach the
saturated zone. Two classes of enhanced degradation are discussed: abiotic
degradation and biodegradation.
Many pesticides undergo abiotic degradation by chemical hydrolysis, which is
usually a second-order reaction in which the degradation rate depends upon the
concentration of the solute and the pH of the system. Information about hydrolysis
reactions is often available from pesticide manufacturers. Both acid- and base-catalyzed
hydrolysis reactions are common for certain classes of pesticides. If subsurface
contamination exists with a pesticide that undergoes acid-catalyzed hydrolysis, lowering
the pH in the unsaturated zone of the source area would enhance the natural degradation
rate of the contaminant source. For such a case, lowering the pH by one unit would
increase the rate of degradation by a factor of 10; lowering the pH by two units would
Page 6-7
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Chapter 6
increase the rate of degradation by a factor of 100 and similarly for other pH changes.
The reverse approachraising the pHwould be appropriate for regions contaminated
with a pesticide that undergoes base-catalyzed hydrolysis.
Nebraska's approach to a number of ground water contamination incidents
attributed to the use of carbon tetrachloride at grain storage sites provides an example of
a range of response actions. Seven sites in Nebraska were Identified as having
contamination levels that significantly exceeded the MCL of 5 ppb for carbon tetrachloride.
The following response activities have been initiated at these sites:
One site, ini Waverly, Nebraska, was placed on the National Priority
Ust due to the ievel of contamination {3120 ppb carbon
tetrachloride) in one water-supply well. Under the Superfund
program, ground water remediation using soil-vapor extraction and
pump-and-treat technology is being undertaken to remove the
carbon tetrachloride contamination.
One well in Bruno, Nebraska, was found to have carbon
tetrachloride contamination above the MCL, but other nearby wells
do not exhibit contamination. Water from the contaminated well is
being blended with water from uncontaminated wells to bring the
combined waters within the drinking water standard. USDA plans to
reimburse Bruno for part of the cost of replacing the contaminated
well.
As an interim measure, EPA has provided bottled water to the
communities of Bruno and WaHon, Nebraska, during studies to
rectify the problem of contaminated drinking-water supplies.
USDA sponsored ongoing studies at Murdock, Nebraska, to
evaluate the extent of the carbon tetrachloride plume. The
contaminated well has been replaced with a larger, deeper well, and
the nearby residents have formed a rural water district to manage
the new well and water supply. :
EPA has identified 70 communities in Nebraska with private wells
that are located in the vicinity of grain storage bins. Outreach efforts
are being planned to communicate the risks and issues surrounding
possible carbon tetrachloride contamination of private wells.
Many pesticides are degraded by microorganisms that may grow in the subsurface
environment. Encouraging biodegradation of a pesticide from a contaminant source zone
is a feasible response to limit the source mass that may contaminate the saturated zone.
In general, enhanced biodegradation is based upon an understanding of conditions that
favor the growth of an appropriate microbial community and the consumption of the
contaminant. A thorough understanding of pesticide characteristics and laboratory
experimentation with site materials would normally be required to guide an enhanced
Page 6-8
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Chapter 6
bioremediation effort. Factors that may enhance remediation are: seeding an appropriate
microbial community; supplying an electron acceptor, e.g., oxygen; providing nutrients
to the microbial community, such as nitrogen, phosphorus, trace elements, or vitamins;
adjusting the moisture content in the unsaturated zone; or elevating the temperature of
the media.
Although the CERCLA program only infrequently addresses issues of pesticides
in ground water at remedial action sites, techniques such as ground water extraction to
address volatile organic compounds have been widely used and analyzed at Superfund
sites. A number of published analyses of these techniques are available in OERR (HSCD)
1989.
6.3 Determination and Evaluation of Contamination Causes
At a minimum, confirmed detections of a pesticide in ground water need to be
treated as a cause for concern, and should trigger some action to diagnose the cause
of the particular detection and determine whether any further regulatory/management
approaches are needed. From a management perspective, this means a determination
of the circumstances that led to the contamination of ground water. Of primary concern
is the determination of whether or not contamination occurred as a result of normal,
registered use of the pesticide, or from misuse.
Some States have involved the registrants of pesticides that have been detected
in ground water in the evaluation process. The State of Florida requires registrant
participation that includes funding of investigations, ground water sampling activities,
and chemical analysis of well-water samples.
Evaluation of the extent of the contamination, and its causes includes
characterizing the contamination in space and time and predicting the ground water
contamination resulting from continued contribution of pollutants. Characterization of a
contamination incident requires knowledge of the nature of the solute source (e.g., mass
of pesticide spilled, or application rate used), rates of degradation, volatilization, uptake,
sorption, leaching, and ground water flow. Several of the vulnerability assessment
methods discussed in Chapter 3 may be useful in evaluating contamination extent and
causes.
Monitoring is also an integral part of the investigation of ground water
contamination causes. Chapter 5 presents information on the development of monitoring
plans in response to detections of pesticides in ground water.
Page 6-9
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Chapter 6
California has also established a process for responding to low-level residues of
pesticides found for the first time, ta California's ground water. The process focuses on
the following steps:
Gathering Information on the contamination site;
Evaluating the extent of contamination and potential contamination
sources by conducting monitoring in the section where
contamination was confirmed and in the sections adjacent to the
detection site;
Assessing whether or not the residues resulted from legal use. If the
use was legal the registrant must request a hearing within 30 days
of notification of the detection in order to avoid cancellation of the ;
pesticide;
If appropriate, modifying the use of pesticides to prevent further
contamination of ground water; and
Conducting monitoring and field studies to evaluate the effectiveness
of response actions.
Based on the response evaluations, the Director of the California Department of
Pesticide Regulation may establish Pesticide Management Zones (PMZs). These PMZs
function as chemical-specific areas identifying those areas that are sensitive to the
migration of pesticide residues in ground water. The use of specific pesticides is restricted
in these areas. In order to use a chemical in its PMZ, users are required to obtain a
special permit from the local County Agricultural Commissioner. To get such a permit,
users must submit a ground water protection advisory written by a licensed Pest Control
Advisor who has completed Department-approved ground water protection training in the
previous 2 years. In addition, monitoring is conducted adjacent to the PMZ to determine
whether or not additional areas should be designated for PMZs. If a pesticide that was
previously subjected to the California response process is again found in ground water,
and it is determined that the residues result from legal agricultural use, then a new PMZ
is created. For additional information on the California response process, contact the
California Department of Pesticide Regulation, Environmental Monitoring and Pest
Management Branch, 1220 N Street, Sacramento, California 85814.
6.4 Use of Reference Points or Action Levels
States will need to identify how to respond to contamination of current or
reasonably expected drinking water from public or private wells before exceeding the
established MCL. States are encouraged to establish action levels at fractions of the
federal enforcement standards (MCLs or HAs). Ground water contamination should then
be evaluated with respect to these action levels to determine the stringency of response
actions.
Page 6-10
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Chapter 6
Whenever evidence indicates an increased risk that ground water contamination'
is approaching or may reach or exceed the reference point or action level, the stringency
of response measures should increase in the contaminated area, and the stringency of
preventive measures should increase in areas of similar vulnerability. In addition, States
should describe the factors and rationale considered in choosing the action levels and
the preventive and response measures. In effect, EPA encourages States to develop
graduated or hierarchical approaches whereby increasingly stringent response measures
will be instituted as levels increase. States are always free to respond more aggressively
to any level of detection in accordance with their ground water protection philosophies
and on the basis of vulnerability assessments, analyses of pesticide usage, and
determination of ground water use and value. Figure 6-1 presents a range of response
measures that can be implemented as pesticide detection levels in ground water
approach the reference point.
In general, a State should consider the following activities in determining its
response plan:
Confirming detections and determine the extent of contamination;
Responding to confirmed detections that are below these reference
levels; and
Responding to confirmed detections that are at or above these
reference levels.
6.4.1 What is Detection?
Detection is generally said to occur when the presence of a designated constituent
is found in ground water. Detection occurs by monitoring for specific pesticides and/or
their reaction products. The presence of contamination should include an analysis to
measure if the constituent concentration is significant given the method detection limits
(MDL) and the spatial and temporal variation of the constituents in ground water.
The method detection limit is the minimum concentration of the designated
pesticide or reaction product measured and reported with a specified confidence (usually
99 percent) that the concentration is above zero. It is an analytical chemistry concept.
As Chapter 5 discusses, practical quantitation limits (PQLs) are often set at 10 times the
analytical MDL and, as the name implies, it is the level at which quantitation of the
designated pesticide or reaction product is practical. Strictly speaking, a detection
occurs anytime a concentration above the MDL is determined in the analytical laboratory.
In cases where MDLs are near the health or regulatory levels, any concentration above
the MDL would be cause for concern. In other instances when the analytical MDL is
much lower than any of the levels of health or regulatory concern, the PQL can be used
Page 6-11
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T)
Q)
(Q
(D
O)
Figure 6-1. Range of Technical Tools for Developing a Response Plan
Reference
Point
A
No
Detection
Type of
Response Action
Implement remediation activ
ities
Implement more stringent
preventive measures
Implement treatment
techniques for public and
private water supplies
Implement additional
preventive measures
Implement initial preventive
measures
Implementation of
Increasingly Stringent
Preventive Measures
Prohibit the use of a pesticide
in specified areas
Institute additional limitations
on pesticide application
techniques and geographic
settings
Limit pesticide application
techniques and geographic
settings
Provide assistance for
Integrated Pest Management
Implement water well
requirements
Implement pesticides
handling, storage, and
disposal requirements
Implementation of
Water Supply
Treatment Programs
Provide alternative sources
of drinking water
Implement treatment for
private water wells
Implement treatment
techniques for pesticides
for public water supplies
Provide technical
assistance to rural well
owners and operators
Provide technical
assistance to local public
water systems
Implementation of
Ground Water
Remediation Techniques
o
o>
B
>
Initiate ground water
remediation activities
-------
Chapter 6
as the reporting limit. Only levels determined to be above that limit are considered
detections. -
In general, one of the following events constitutes confirmation of pesticide
contamination:
Detection;
Detection at a level of concern (i.e., the MCL); or
Qualitative determinations of presence at some level.
The level of confirmation may involve field and/or laboratory analyses.
6.4.2 Responding to Detections Below the MCL or HA
Detections of pesticides in ground water that are well below established MCLs or
HAs provide the widest range of response options. If pesticide contamination is found
to originate from a point source (e.g., spill) or from direct contamination of ground water
(e.g., improper well abandonment), then a State may consider implementing more
stringent measures that will prevent these types of point source contamination (See
Section 4.2.1). If nonpoint source contamination is suspected, then more stringent
preventive measures, described in Sections 4.2.2 and 4.2.3, should be considered.
Depending on ground water use and value characteristics and social and economic
values, appropriate response measures may range from voluntary or education-based
approaches to more stringent regulatory approaches. Continued or increased monitoring
efforts are an integral part of response actions for low-level detections. Monitoring may
enable States to both evaluate potential causes for the contamination and assess the
effectiveness of response actions.
As levels of confirmed contamination approach the reference level, response
measures should become more stringent in their control of pesticide use. Special
restrictions on pesticide use in sensitive areas, permitting, area restrictions, or use
prohibitions are among the approaches that States should consider in response to
escalating levels of contamination.
It should be recognized that there are substantial scientific limitations at this time
in the State of the art of both monitoring and mathematical modeling to predict the
behavior of pesticide residues in the subsurface environment. Consequently, a graduated
approach to pesticide management may not always be a practical possibility. Also,
pesticide levels detected in ground water have been known to fluctuate substantially over
relatively short periods of time. For example, a heavy rainfall can cause such fluctuation.
Thus, a detection at levels well below the MCL or reference point will not always offer
assurance that there is time for a gradual escalation of preventive measures in order to
prevent contaminant concentrations from reaching the MCL Another relevant factor is
that for some pesticides the MCL or health advisory level is quite low in relation to the
limits of analytical detection. In such cases, a positive detection may be so close to the
MCL that it would justify very stringent response measures.
Page 6-13
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Chapter 6
Wisconsin's Generic Ground Water Rule provides that if a pesticide is found in
ground water in Wisconsin, the Department of Agriculture, Trade, and Consumer Protection
will investigate the incident to determine the following:
Whether the presence of the pesticide resulted from a violation of a
existing statute, rule, or order; and
» Whether the concentration attains or exceeds an enforcement
. standard or preventive action limit.
tf the presence of the pesticide resulted from misuse, even if the concentration does not
exceed an enforcement standard or prevention action limit, the Department may proceed
by following one of its enforcement options.
Whether or not a pesticide residue results from a violation of a statute or rule, if the
pesticide concentration exceeds an enforcement or preventive action limit, the State of
Wisconsin may implement any one or combination of "site-specific responses," including:
Prohibitions against the use of a pesticide;
Limitations on the purposes for which a pesticide may be used;
Limitations on the fate at which a pesticide is applied;
Limitations on the time and frequency of pesticide use;
Limitations on the method of pesticide use; and
Requirements for the training or certification of pesticide applicators
or other persons.
For additional information on the Wisconsin Generic Ground Water Rule, contact the
Wisconsin Department of Agriculture, Trade, and Consumer Protection, 801 West Badger
Road, Post Office Box 8911, Madison, Wisconsin, 53708-8911.
6.4.3 Responding to Detections At or Above the MCL or HA
Detections of pesticides in ground water that are at or above established MCLs or
HAs signify the failure of the SMP. If the contamination is detected within a public-water
supply at a level above the MCL, the contamination also constitutes a violation of the
SDWA. Although SDWA regulations do not apply to private wells, most States use these
or similar standards as a basis for informing well owners of health risks. Some State laws
also require closure of private wells that do not meet drinking-water standards. As a
minimum, States should respond to high-level detections of pesticides in ground water
by notifying the affected users of the ground water resource and by providing alternative
supplies of safe drinking water.
Page 6-14
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Chapter 6
6.5 References
Keely, J.F. 1989. Performance Evaluations of Pump-and-Treat Remediations. U.S.
Environmental Protection Agency, Ground Water Issue. EPA 540/4-89/005. 19 pp.
Maine Board of Pesticide Control. 1990. Proposed Pesticides in Ground Water
Management Plan. 92 pp.
Mercer, J.W., D.C. Skipp, and D. Giffin. 1990. Basics of Pump-and-Treat Ground Water
Remediation Technology. U.S. Environmental Protection.Agency, Office of Research and
Development. EPA 600/8-90/003. NTIS PB90-274549. 67 pp.
U.S. EPA, Office of Emergency Response and Remediation. 1988. Guidance on
Remedial Actions for Contaminated Ground Water at Superfund Sites. EPA 540/g-88/003.
180 pp.
U.S. EPA, Office of Emergency Response and Remediation. 1989. Determining Soil
Response Action Levels Based on Potential Contaminant Migration to Ground Water: A
Compendium of Examples. EPA 540/2-89/057. 145pp.
U.S. EPA, Office of Emergency Response and Remediation (HSCD). 1989. Evaluation
of Ground Water Extraction Remedies. Volume 1: Summary Report. EPA 540/2-89/054.
65 pp.
U.S. EPA, Office of Emergency Response and Remediation (HSCD). 1989. Evaluation
of Ground Water Extraction Remedies. Volume 2: Case Studies 1-19 (Interim Final). EPA
540/2-89/0540. 557 pp.
U.S. EPA, Office of Emergency Response and Remediation (HSCD). 1989. Evaluation
of Ground Water Extraction Remedies. Volume 3: General Site Data. Data Base Reports
(Interim Final). EPA 540/2-89/054c. 121pp.
U.S. EPA, Office of Research and Development and Office of Emergency Response and
Remediation. 1990. Remediation Completed: But is the Ground Water Meeting the Safe
Drinking Water Act Requirements? EPA 600/d-90/089. NTIS PB90-272576. 22 pp.
Page 6-15
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Chapter 7
Chapter 7
Sources of Technical Information
State and local agencies can be important sources of technical information for
SMPs. Input from State agriculture, geology, water quality, and health agencies is critical
to the development of SMPs. Several federal agencies and other national centers can
also provide useful technical information to States. Although many of the federal sources
are located near Washington, D.C., there are numerous organizations operating at the
State or local levels that act as clearinghouses for technical information. For example, the
USDA maintains State and local offices for the Soil Conservation Service and the
Agricultural Stabilization and :Conservation Service.
In addition to the contacts listed
below, the National Technical Information
Service (NTIS) is a central source for the
public sale of technical and nontechnical
information that is published by U.S. and
foreign government agencies. The infor-
mation available from NTIS includes
research, development, engineering, and
business reports. When ordering a
document from NTIS, it is useful to
reference the document's unique NTIS
number (NTIS number for many EPA
documents begin with PB). NTIS
document numbers may be obtained
through NTIS's Government Report
Announcement and Index (published
annually and twice a month), the online
Identification Department.
NTIS
5285 Port Royal Road
Springfield, VA 22161
(703) 487-4650 (to order documents)
(703) 487-4780 (NTIS Identification Department)
!NCEPI 7;.V;.'. :-.:r ";;:v -:-:-.' /' : '..:.:; .;.... '
11029 Kenwood Road
Building 5 :'
Cincinnati, OH 45242
(513) 569-7980
CERI -
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513)569-7562
NTIS Bibliographic Data Base, or NTIS's
EPA's ACCESS EPA System (NTIS document number for 1992 edition: PB92-
147438) provides access to EPA's environmental information. The document consists of
seven chapters that list and describe environmental information available from EPA.
Selected EPA documents may be ordered from the following sources:
EPA National Center for Environmental Publications and Information
(NCEPI) - clearinghouse for scientific/technical and public-oriented
environmental information that is published by EPA; and
EPA Center for Environmental Research Information (CERI) -
clearinghouse for scientific/technical and public-oriented
environmental information that is supported by EPA's Office of
Research and Development (ORD).
Page 7-1
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Chapter 7
Some of the U.S. government publications listed in the reference sections at the end of
each chapter include NTIS and/or EPA document reference numbers.
Chapter 7 is organized into eight sections. Section 7.1 identifies the SMP
components where technical information will be useful to States and the categories of
information that States may need to develop these components. Sections 7.2 through
7.6 discuss the information maintained by the federal agencies and national research
centers that address pesticides and/or ground water-related issues. Section 7.7 provides
contacts for obtaining the information presented in this chapter. Section 7.8 provides
selected references.
7.1 Categories of Technical Information
Technical information from outside sources will be useful to States that are
developing the following components of their Generic or Pesticide SMPs:
Basis for Assessment and Planning (component 5);
Monitoring (component 6); .
Prevention Actions (component 7); and
Response to Detections of Pesticides (component 8).
To develop these SMP components, States need the following categories of information:
Pesticides. Product information on specific pesticides and estimates
of the use of these pesticides at a State or sub-county level.
Hydrogeology. Guidance materials and technical assistance to
assess risks to States' ground water resources, including
characterizing the vulnerability of ground water to contamination.
Existing compilations of hydrogeologic data.
Water Quality. Drinking water MCLs and HAs as well as State water
quality standards. Guidance materials and technical assistance for
monitoring ambient water quality.
i
Public Health and Ecosystems. Research reports on health risks
posed to humans resulting from exposure to pesticides. Research
report on the impacts of pesticides on ecosystems.
Fate and Transport Information and Models. Guidance, technical
assistance, research reports that address occurrence (including
levels), movement, and quality of ground water in relation to the
occurrence, quantity, and movement of pesticides. Tools for
modelling the relationships between pesticide use and ground water
quality.
Page 7-2
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Chapter 7
Agricultural Practices. Guidance materials, education programs,
and research reports on the impacts of agricultural practices on
ground water quality.
Conservation Implementation and Cost-Sharing. Technical
assistance and outreach programs for implementing -agricultural
practices (e.g., contour plowing, filter strips, etc.) that reduce the
impacts of pesticides on ground water quality from pesticide
leaching or runoff.
.Alternative Technology. Technical assistance, outreach programs,
and research reports for implementing agricultural practices (e.g.,
low input sustainable agriculture) that reduce the use of pesticides.
Table 7-1 provides a summary of the national research centers, programs, data
bases, agency bureaus, and key studies for selected federal agencies that are sources
of information for one or more of the information categories.
Sections 7.2 through 7.5 provide a further description of the information available
from the U.S. Environmental Protection Agency, U.S. Department of Interior, U.S.
Department of Agriculture, and National Oceanic and Atmospheric Administration,
respectively. Section 7.6 discusses information maintained by research centers
associated with nonprofit organizations or government trusts. Readers can obtain
information presented in Sections 7.2 through 7.6 by using the list of contacts found in
Section 7.7. Section 7.8 provides a list of selected references useful for the development
ofSMPs.
7.2 Sources of Information from the U.S. Environmental Protection
Agency (EPA)
EPA's Office of Water and Office of Information Resources Management have
released a document entitled Office of Water Environmental and Program Information
Systems Compendium: Fiscal Year 1990. which covers most major information systems
within EPA as well as important sources in other Federal agencies (U.S. EPA, 1990).
Additional references may be found in an Office of Technology Assessment report on
agrichemical issues (OTA, 1990) and an Office of Ground Water Protection1 (U.S. EPA,
1988) study on agricultural management practices for pesticide pollution control. In
addition, several specific EPA information sources are discussed in the following
subsections. '
1 EPA's Office of Ground Water Protection is now the Ground Water Protection
Division in the Office of Ground Water and Drinking Water. Documents are identified
according to the name of the organization at the time the document was published.
Page 7-3
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0)
(Q
0)
Table 7-1. Selected Sources of Information
g
0)
SOURCES
U.S., Environmental Protection Agency
National Pesticide Survey
Pesticide Information Network
1 National Estuarine Program
Pesticide Information Network
Pesticides In Ground Water Data Base
Comprehensive State Ground Water Protection
Program
Nltrogon Action Plan
Agriculture Pollution Prevention Strategy
Clean Water Act Programs
Safe Drinking Water Act Programs
SrORIET
FRDS
ORD Ground Water Research Program
Special Toxlcity Data Bases
U.S. Department of Interior
U.S. Geological Survey
U.S. fish and Wildlife Service
U.JJ. Department of Agriculture
Agricultural Stabilization & Conservation
Service
Agricultural Research Service
INFORMATION CATEGORIES
Pesticide
Product
Info.
/
/
Hydro-
geology
/
/
/
/
/
Water
Quality
/
/
/
/
/
/
/
/
/
/
/
/
/
Public
Health ft
Ecosystems
/
/
/
/
/
/
/
/
/
'
Fate ft
Transport
Models
/
/
/
/
/
/
S
/
/
Agricul-
tural
Practices
/
/
/
/
/
/
/
Conserva-
tion ft
Cost-
Sharing
/
/
/
/
/
Alternative
Technology
/
,
-------
Table 7-1. Selected Sources of Information (continued)
TJ
0>
CD
0>
SOURCES
Cooperative State Research Service and State
Agricultural Experiment Stations
National Agricultural Pesticide Impact
Assessment Program
Cooperative Extension Service
Economic Research Service/National
Agricultural Statistics Service
Forest Service
Soil Conservation Service
National Oceanic & Atmospheric
Admin.
National Coastal Pollutant Discharge Inventory
Coastal Zone Management Act
Other Sources
Institute for Alternative Agriculture
Land Stewardship Project
Conservation Technology Information Center
TVA/National Fertilizer and Environment
Research Center
National Pesticide Information Retrieval System
Fish and Wildlife Information Exchange
National Center for Food and Agricultural
Policy --.-..
INFORMATION CATEGORIES
Pesticide
Product
Info.
/
/
/
/
/
/
/
/
/
Hydro-
geology
/
/
/
/
Water
Quality
/
/
/
/
Public
Health &
Ecosystems
/
/
/
/
Fate*
Transport
Models
/
Agricul-
tural
Practices
/
/
/
/
/
/
/
Conserva-
tion &
Cost-
Sharing
/
/
/
Alternative
Technology
/
/
/
/
/
/
/
/
o
Q)
T3
r-*
CD
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Chapter 7
7.2.1 National Survey of Pesticides in Drinking Water Wells
Early in 1992 the EPA Office of Ground Water and Drinking Water and the Office
of Pesticide Programs completed a joint multiyear national survey of pesticides in drinking
water wells. Between 1988 and 1990, EPA sampled 1,349 community water system wells
and rural domestic wells for the presence of 101 pesticides, 25 pesticide degradates, and
nitrate (127 total analytes). In Phase I, completed in November 1990, EPA developed
national estimates of the frequency and concentration of pesticides and nitrate present
in drinking water wells in the United States. The Phase II report, issued in January 1992,
analyzed the NPS data alone and in combination with pertinent data from non-national
pesticide survey sources. This report investigated how the presence of pesticides and
nitrate in drinking water wells might be associated with patterns of pesticide use, the
sensitivity of areas surrounding drinking water wells to ground water contamination,
transport of chemicals to well water* and other factors, including pesticide chemistry and
the physical condition of drinking water wells.
The Phase I Report provides a detailed summary of the survey design, survey
implementation, analyte selection and analysis, quality assurance/quality control
procedures, and national estimates of the occurrence and frequency of detections of
pesticides and nitrate in drinking water wells. The Phase I Report also includes detailed
appendices on statistical design, survey implementation, tabulations of data, and. copies
of the survey questionnaires.
The National Pesticide Survey Phase II Report discusses the statistical approaches
followed in the Phase II studies and provides results of analyses involving a broad range
of data sources. It also provides recommendations for future studies.
In addition to the National Pesticide Survey Phase I Report and Phase II Report,
the survey also produced eight multiresidue chemical analytic methods, quality assurance
plans, training materials and protocols for well sampling and sample handling, fact-sheets,
health advisories, health advisory summaries, and a number of data files. Copies of many
of these materials or access to data can be obtained through the National Technical
Information Service or the EPA Office of Pesticides Programs Docket.
7.2.2 Pesticide Information Network (PIN)
Pesticide Information Network is a collection of files containing up-to-date pesticide
information and is maintained by EPA's Office of Pesticide Programs. Located on a
personal computer, PIN is accessible by dataphone similar to a«PC-to-PC bulletin board.
Files currently available through PIN are: :
The Pesticide Monitoring Inventory .containing information on
pesticide monitoring projects performed by federal, State, and local
governments and private institutions;
The Restricted-Use Products File containing a comprehensive list
of all pesticide products that have been classified as Restricted-Use
Page 7-6
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Chapter 7
Pesticides under 40 CFR Part 152, Subpart I. This file is updated
monthly; and
The Chemical Index containing a list of all chemicals contained in
the Pesticide Monitoring Inventory and Restricted-Use Products File.
All chemicals are cross-referenced to synonyms and Chemical
Abstracts System (CAS) numbers.
7.2.3 Pesticides in Ground Water Data Base (PGWDB)
The PGWDB is a collection of ground water monitoring studies conducted by
federal, State, and local governments, the pesticide industry and private institutions. The
PGWDB consists of monitoring data and auxiliary information in both computerized and
hard-copy form. The PGWDB provides an overview of the ground water monitoring
efforts for pesticides in the United States, pesticides that found in the nation's ground
water, and the areas of the country that appear vulnerable to pesticide contamination.
The computerized portion of the PGWDB will become a part of the PIN in 1993.
7.2.4 Comprehensive State Ground Water Protection Program (CSGWPP)
CSGWPPs are the focal point for a new partnership between EPA, the States,
Native American Tribes, and local governments to achieve a more efficient, coherent, and
comprehensive approach to protecting the nation's ground water resources. CSGWPPs
are an important step in implementing EPA's ground water protection goals and
principles. EPA is seeking to make the Comprehensive Program approach the catalyst
for fundamental change in the development and implementation of ground water
protection programs at the federal, State, and local levels. A CSGWPP consists of the
following six strategic activities: (1) establish goal; (2) establish priorities, based on
characterization of the resource, identification of sources of contamination, and
programmatic needs; (3) define roles, authorities, responsibilities, resources, and
coordinating mechanisms; (4) implement necessary activities; (5) collect and manage
information; and (6) ensure public participation. The Strategic activities foster more
efficient and effective ground water protection through more cooperative, consistent, and
coordinated operation of all relevant federal, State, and local programs within a State.
7.2.5 Nitrogen Action Plan (NAP)
The Nitrogen Action Plan is the result of EPA strategic planning and involves the
coordination of a number of EPA offices in order to protect ground water and surface
water from all sources of contamination by nitrate and related nitrogen compounds
through pollution prevention. Currently, the NAP is in the planning and development
stages. Once operational, the NAP will provide technical assistance and educational
support to promote the reduction of fertilizer use and to improve the control of runoff and
infiltration from livestock operations.
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7.2.6 National Estuarine Program (NEP) and Chesapeake Bay Program
The Chesapeake Bay Program is the exemplarfor over a dozen estuarine studies-
under the NEP defined in the Clean Water Act's Section 320. These estuarine studies
conduct assessments of toxics impacts from both point and nonpoint sources, including
possible inputs to the estuarine systems from ground water. Protection or remediation
strategies defined under the NEP's Comprehensive Conservation and Management Plans
could be useful components for inclusion in Pesticide SMPs.
7.2.7 Clean Water Act Programs
The objective of the Clean Water Act is to restore and maintain the chemical,
physical, and biological integrity of the nation's waters. Several Clean Water Act
programs provide information useful for the development of pesticide SMPs.
Section 319. State Assessment Reports and Management Plans
developed under the Section 319 Nonpoint Source program provide
summaries of assessment information on surface water and ground
water conditions, including information on contamination from
pesticides. Priority ground waters identified under this program can
be used to target critical areas for SMPs. The Section 319 process
has resulted in the development of sets of BMPs for use in
protecting surface water quality and for remediating water-quality
problems. States have outlined a series of management activities
that may include projects dealing with ground water problems to
promote the implementation of approved BMPs. Suitable Section
319 BMPs constitute one possible source of protection and
remediation techniques for inclusion in Pesticide SMPs. Nonpoint
Source Program (NPS) is a grant program which provides annual
grants to States to address NPS pollution. Grant requirements are
flexible, so States can address NPS problems in a prioritized fashion.
Section 305. This section provides a major mechanism for States
to report assessment information on the condition of their surface
water and ground water supplies. EPA summarizes these biennial
State submittals in a report to Congress and stores information in a .
data base called the Waterbody System.
Section 304. Under this section of the Clean Water Act, EPA is
authorized to publish and update ambient water quality criteria.
These criteria provide guidance on the environmental effects of
pollutants and may be useful to States in deriving regulatory
requirements. The water quality criteria reflect the current scientific
knowledge of the impacts of pollutants on surface water and ground
water ecosystems. A document entitled "Quality Criteria for Water
1986," also referred to as the "Gold Book" contains summaries of the
water quality criteria for all the contaminants for which EPA has
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Chapter 7
developed recommendations, as well as a detailed description of the
procedures used to derive the recommendations. This document is
available through the U.S. Government Printing Office (Order No.
955-002-00000-8.) Information on new or revised water quality
criteria and standards for aquatic life can be obtained from the EPA
Office of Science and Technology.
Section 402. The National Pollutant Discharge Elimination System
(NPDES) program established under this section addresses the
problem of feedlot contamination. The problems presented by
feedlots frequently stem from contamination by conventional
pollutants (phosphorous, nitrogen, etc.). The NPDES program will
develop a permitting/enforcement guidance on feedlots that expands
the focus of permits to best management practices (BMPs) including
land application, manure storage, and composting.
7.2.8 Safe Drinking Water Act Programs (SDWA)
Several SDWA programs currently operating through the EPA Office of Ground
Water and Drinking Water can provide support for Pesticide SMPs:
Public Water Supply Program. This program establishes and
enforces drinking water standards under the authority of the Safe
Drinking Water Act. Maximum Contaminant Level (MCL) standards
exist for 26 pesticides, nitrogen compounds, and other contaminants.
In practice, the quality of the water entering the distribution system
is monitored. In many cases the water has been treated and the
analytical results may not reflect actual ground water quality.
Treatment generally consists only of chlorination, but may also
include aeration or softening. Provisions are available by which
States may waive sampling requirements if certain conditions are
met.
Wellhead Protection Program. Established to protect public
ground water supplies from contamination. States develop and
implement land-use controls and other preventive measures for all ,
sources of contamination within wellhead protection areas. The
promotion of best management practices for agriculture-related
sources of contamination is currently under consideration.
Sole Source Aquifer Programs. Provides protection plans for
selected aquifers that include a map showing the detailed boundary
of the critical protection area and an assessment of the relationship
between activities on the land surface and ground water quality.
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Chapter 7
UlC Program: Class V Wells. Affords protection of all
underground sources of drinking water from contamination by well
operations. States may obtain primacy to implement the program.
7.2.9 Federal Reporting Data System (FRDS)
FRDS is an automated data base for the Public Water System Supervision Program
'maintained by EPA's Office of Ground Water and Drinking Water. It contains information
about public water supply systems and their compliance with monitoring requirements,
MCL regulations, and other Safe Drinking Water Act (SDWA) requirements. The system
lists public water-supply systems by source (ground water or surface water) and by site.
Contact Regional EPA offices and State SDWA lead agencies for access.
7.2.10 Storage and Retrieval of U.S. Waterways Parametric Data System (STORET)
The STORET data base is maintained by EPA's Office of Water. STORET is
oriented primarily toward surface water monitoring sites. STORET also contains ground
water monitoring data. The system has links to a number of other data files (e.g., the
STORET Fish Kill File and BIOS for biological data) and is now being linked to
sophisticated data integration and mapping systems to modernize its user interface and ;
report writing capabilities.
7.2.11 Office of Research and Development (ORD) Ground Water Research Program
ORD offers expertise and publications in many aspects of ground water science,
including the monitoring, fate, and transport of pesticides. One service provided through
the ORD Ground Water Research Program is the Center for Exposure Assessment
Modeling (CEAM) which provides a wide range of predictive modeling tools for water, air,
soil, and multimedia assessments of organic chemicals and metals. CEAM maintains a
distribution center for models and data bases. All computer programs distributed by
CEAM are in the public domain and are freely available to users. For example, the
Pesticide Root Zone Model (PRZM) predicts the leaching of pesticides. Examples of data
bases include soils Data Base Analyzer Parameter Estimator (DBAPE) and historical
weather data. A recently initiated data base, FATE: The Environmental Fate Constants
Information System Data Base, provides fate parameters for pesticides.
7.2.12 Special Toxicity Data Bases
Several toxicity data bases are available to assist in the development of SMPs.
These include:
LISTS. An inventory of about 1,716 chemical substances regulated
by EPA giving all pertinent regulatory programs with oversight over
the substances and references to commonly accepted analytical
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AQUIRE (Aquatic Toxicity Information Retrieval Data Base).
Contains aquatic toxicity information for over 5,000 chemicals and
over 2,400 test species extracted from available scientific literature,
including coverage for sublethal effects and bioaccumulation
impacts.
IRIS (Integrated Risk Information System). A data base that
offers human health risk information useful in decision-making and
regulatory activities involving risk assessment.
TRIS (Toxic Chemical Release Inventory System). A data
resource created in response to the 1986 Superfund amendments
that Contains extensive information on toxic chemicals stored or
released in large volumes from facilities nationwide. Information on
agricultural chemicals, however, is generally not included in this
system.
7.3 Sources of Information from the U.S. Department of Interior
The U.S. Department of Interior includes several agencies that may provide useful
technical assistance or information to States.
7.3.1 U.S. Geological Survey (USGS)
The responsibilities of the U.S. Geological Survey include investigating and
assessing the nation's land, water, energy, and mineral resources. To study water, the
USGS conducts nationwide assessment of the quality, quantity, and use of the nation's
water resources. Information is available through the National Water Data Exchange
(NAWDEX), which includes information on over 450,000 sites for which water information
is available from over 400 organizations. Although NAWDEX is not a medium for the
actual storage of water quality data, it does provide a convenient directory for determining
if specific types of information are available. The USGS's own water quality data
collections are maintained in the national Water Storage and Retrieval System
(WATSTORE). NAWDEX assistance centers and data on regional water resources are
maintained at each of the USGS Water Resources Division District Offices. Section 7.7,
Table 7-2, provides contact information for WATSTORE and NAWDEX.
i
The Regional Aquifer Systems Analysis Program (RASA) has led to the
development of detailed computer simulation models to define the chemical quality and
discharge-recharge features of numerous major aquifer systems. The U. S. Geological
Survey (USGS) also conducts the following water-resource programs:
Federal-State Cooperative Program;
Toxic Substances Hydrology program;
Water-Use program;
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Irrigation/Drainage program;
National Water Quality Assessment Program; and
Grant support to the 54 State and Territory Water Resources
Institutes.
The USGS also cooperates with local, State, and federal agencies to operate a network
of streamflow gauging stations. Other relevant projects include the Mid-Continent
Initiative, which has helped characterize the environmental fate of such herbicides as
atrazine in ground water and surface water systems in the Upper Missouri and Ohio River
Basins. .
The National Geologic Mapping Program conducts prioritized investigations
relevant to social and scientific issues facing the nation, such as the susceptibility of
ground water to contamination from agricultural activities. Resulting map products and
research include information about the distribution, composition, stratigraphic setting, and
geologic history of Earth materials. The GEOINDEX data base contains references to
modern geologic mapping. In addition, the PLUTO data base contains geochemical data
on rocks, soils, sediments, plants, water, and other materials.
7.3.2 Fish and Wildlife Service (FWS)
The Fish and Wildlife Service is responsible for migratory birds, endangered
species, certain marine mammals, inland sport fisheries, and specific fishery and wildlife
research activities. In particular, FWS has the primary responsibility for enforcing the
Endangered Species Act. Threatened or endangered species are an ecological concern
in developing pesticide SMPs for critical habitat areas where ground water is closely
hydrologically connected with surface waters. To address issues related to routine field
applications of pesticides affecting terrestrial or surface water critical habitat areas, many
States are working with the FWS and EPA's FIFRA program to add protection measures
to species recovery plans for organisms ranging from the leopard darter to numerous
migratory birds. Features of these species recovery plans might also apply to protection
provisions in Pesticide SMPs.
7.3.3 Additional Sources from the U.S. Department of Interior
i
The Bureau of Land Management (BLM), the Office of Surface Mining Reclamation
and Enforcement (OSM), and the Bureau of Reclamation may also provide ground water
data, especially in western States with large tracts of public lands. The BLM is
responsible for the total management of more than 270 million acres of public lands/.. In
addition to managing watersheds to protect soil and enhance water quality, BLM
manages wildlife habitat, endangered plant and animal species, and designated
conservation and wilderness areas.
The primary goal of the Office of Surface Mining Reclamation and Enforcement is
to assist States in operating a nationwide program that protects society and the
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environment from the adverse effects of coal mining, while ensuring that surface coal'
mining can be practiced without permanent damage to land and water resources.
The Bureau of Reclamation administers a reclamation program that provides the
arid and semiarid lands of the 17 contiguous western States a secure, year-round water
supply for irrigation. The Bureau's functions include groundwater management, water
quality and environmental enhancement, and development of water conservation plans.
The Bureau of Indian Affairs assists Indian and Alaska Native people in managing
their own affairs under the trust relationship to the federal government. In particular, the
Bureau can serve as a liaison between the States and many sovereign American Indian
groups.
7.4 Sources of Information from the U.S. Department of Agriculture
(USDA)
Of the 36 operating entities within the USDA, ten share' responsibilities for
implementing the President's Water Quality Initiative for Agriculture. Of these entities, nine
USDA agencies particularly relevant for Pesticide SMPs are discussed in the following
subsections.
7.4.1 Agricultural Stabilization and Conservation Service (ASCS)
The ASCS plays a central role in transfer of payments for major USDA commodity
support programs. Starting with the 1985 Food Security Act (1985 Farm Bill), cross-
compliance provisions required recipients of ASCS assistance to prepare and implement
conservation plans, whose water quality protection features have become steadily more
important. Under the President's Water Quality Initiative and provisions added in the 1990
Farm Bill reauthorization (1990 Farm Bill), the ASCS will work with the SCS and other
USDA agencies to promote cost-sharing for special integrated crop management
practices designed to protect ground water from agricultural chemicals. The outcome of
these projects may be useful to States in the development of SMPs. The ASCS's
ongoing Agricultural Conservation Program (ACP) also provides cost-share assistance
for implementing a variety of water-quality-oriented BMPs.
7.4.2 Agricultural Research Service (ARS)
i
The ARS administers fundamental and applied research that address a wide-range
of agriculture-related issues, including the conservation of soil, water, and air and the
processing, storage, and distribution of farm products. The ARS has developed a
number of fate and transport models that focus on pesticides. For example, Chemical
Runoff, and Erosion from Agricultural Management Systems (CREAMS) and Ground
Water Loading Effects from Agricultural Management Systems (GLEAMS) evaluate the
effects of agricultural management practices on the transport of pesticides in the root
zone, and describe rainfall, infiltration, and runoff processes. Pesticide degradation,
volatization and plant uptake are also included in these models.
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7.4.3 Cooperative State Research Service (CSRS)
A major responsibility of the CSRS is to fund research through the State-
Agricultural Experiment Station (SAES) for the advancement of science and technology
in support of agriculture. Other research programs conducted by CSRS, and funded by
special grants, include a ground water research grants program; a supplemental and
alternative crop program; a low-input agricultural program; and the National Research
Initiative (NRI) competitive grant programs in natural resources, water quality, ecosystems,
and wetlands.
The SAES is responsible for the National Agricultural Pesticide and Impact
Assessment Program (NAPIAP), which is a source for pesticide-use data. Specifically,
the NAPIAP provides grant monies to States for conducting pesticide use and benefit
studies that are mutually beneficial to States and NAPIAP. In addition, the CSRS is
responsible for developing a forum for coordination between the State Agricultural
Experiment Stations, the USDA, and other federal agency scientists.
7.4.4 Extension Service (ES)
The ES is the educational bureau of the USDA and serves as the federal partner
in the Cooperative Extension System. More specifically, the ES coordinates its activities
with State land grant universities and local county extension offices to conduct research
and to provide outreach and technical assistance programs. The CES is especially active
in supporting improved training of pesticide applicators and promoting integrated pest
management programs (or similar integrated crop management or integrated farm
management programs) and low-input sustainable agriculture techniques that can
significantly reduce the use of pesticides.
7.4.5 National Agricultural Library (NAL)
The NAL provides information services over a broad range of agricultural interests,
including alternative farming systems, biotechnology, technology transfer, and water
quality. NAL maintains the AGRICultural OnLine Access data base (AGRICOLA), which
provides an online bibliography of agriculture-related literature. NAL also maintains the
USDA/CRIS (Current Research Information System) data base, which provides online
access to information on federal- and State-supported research in agriculture,
environmental protection, forestry, and related fields. The AGRIS data base serves as a
comprehensive inventory of world-wide agricultural literature and is also maintained at
NAL. In addition, the Water Quality Information Center (WQIC), within NAL, serves as a
focal point for disseminating information related to quality and quantity of water resources
as they affect or are affected by agricultural production practices.
7.4.6 Forest Service (FS)
The FS is a national leader in forestry through its management of the National
Forest System. A key objective of the FS is to promote natural resource conservation
through cooperative efforts with other federal, State, and local agencies. The FS provides
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technical assistance to State forestry programs in order to protect and improve the quality
of air, water, and soil resources. Also, the FS's National Forest Assistance provides.
information on the use of pesticides in modern silvicultural practices.
7.4.7 Soil Conservation Service (SCS)
The primary responsibility of the SCS is to develop and implement a National Soil
and Water Conservation Program in cooperation with landowners and operators,
resource groups, and other federal and State agencies. As part of this effort, the Soil
Conservation Service provides technical assistance to other USDA entities and to State
soil and water conservation districts for developing management practices. These
management practices are frequently adopted by States as water quality best
management practices. In preparing the standards and specifications for proper
pesticide use practices, the SCS has developed a considerable amount of information on
the suitability of common pesticides~for specific soils, cropping systems, and locations
within each State. This information can be beneficial in developing Pesticide SMPs. The
SCS developed the Soil/Pesticide Interaction Screening Procedure (SPISP) to assist in
screening soil-pesticide interactions. SPISP was designed to assist field personnel in
determining if the use of a particular pesticide on a given soil may result in pesticide
losses of sufficient size to be detrimental to a water resource of concern. The results are
intended to be a first tier evaluation of pesticide use and was developed on the results
of several thousand runs of the GLEAMS model.
7.4.8 Economic Research Service (ERS) and National Agricultural Statistics Service
(NASS)
The ERS and the NASS work with State departments of agriculture to gather
estimates on production characteristics for major farm commodities. Such statistics
currently constitute one way to build county profiles of pesticide use based on indirect
evaluation techniques. ERS and NASS are initiating a new program to begin actual data
gathering on pesticide use. As this program expands, it should provide a more direct
means of estimating agricultural pesticide use patterns within a State.
7.5 Sources of Information from the National Oceanic and
Atmospheric Administration (NOAA)
NOAA's mission includes exploring, documenting, and predicting conditions in the
atmosphere and ocean, and managing and disseminating long-term environmental
information. NOAA also conducts extensive research related to the protection of marine
resources and their habits. In addition, NOAA provides satellite observations of the
environment by operating an environmental satellite system.
NOAA has begun a program to document major types of pollutant discharges to
coastal waters. The National Coastal Pollutant Discharge Inventory (NCPDI) includes
estimates on the use of such agrichemicals as fertilizers and pesticides in 78 estuarine
drainage areas rimming the contiguous United States. NOAA has also developed a
vulnerability index to facilitate relative comparisons of potential risks from pesticide usage.
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This information can be helpful in building a pesticide use data base for coastal areas
within a State.
The 1990 Amendments to the Coastal Zone Management Act (CZMA) of 1972 will
require enhanced treatment of nonpoint source pollution in all State coastal management
programs. Changes are also required in State Clean Water Act Section 319 Nonpoint
Source (NPS) Plans as a result of the CZMA Amendments. A key provision of the CZMA
amendments will lead to the development of federal guidance containing a detailed
technical description of BMPs for improving water quality. This BMP technical guidance
should include many protection or remediation practices that would be useful in pesticide
SMPs. The Coastal Nonpoint Source Program (CNPS) is a development of State
programs to ensure implementation of NPS management measures to restore and
protect coastal waters. .
7.6 Other Sources
There are a number of centers associated with nonprofit foundations or
government trusts that could be valuable sources of information in developing pesticide
SMPs. The following selection of organizations is hardly exhaustive but does give brief
descriptions of several important organizations.
7.6.1 Institute for Alternative Agriculture
The Institute serves as a major national clearinghouse for information on cost-.
effective alternative farming practices, which reduce the potential for ground water
contamination from pesticides.
7.6.2 Land Stewardship Project
The Project is an important center in the Midwest for addressing issues that relate
to alternative technology, specifically low-input sustainable agriculture.
7.6.3 Conservation Technology Information Center
The Center is a clearinghouse for information encouraging conservation systems
for soil, water, and croplands. The Center provides fact sheets on a variety of topics
related to ground water protection from agricultural chemicals. The Center has been very
active in efforts in the Midwest associated with Clean Water Act programs, including the
Section 319 NPS Management Program and the Great Lakes Program.
7.6.4 National Fertilizer and Environmental Research Center (NFERC)
NFERC has long been a major regional clearinghouse for information on the
proper use of fertilizer materials. Its mission was broadened in 1990 to encompass a
wider set of environmental concerns. NFERC and the Tennessee Valley Authority have
been very active in developing management strategies for nonpoint source pollution
issues in the Appalachians.
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7.6.5 National Pesticide Information Retrieval System (NPIRS)
NPIRS is a data base maintained by Purdue University containing EPA and State
registration information on more than 60,000 federally registered pesticide products and
other non-pesticide chemicals. Information available from the data base includes product-
specific data, State product data, experimental use permits, and emergency exemptions.
The facility also provides fact sheets on specific pesticide products with regional
estimates of use patterns, scientific findings on the chemical, tolerance assessments, and
problems known to occur with use of the chemical.
7.6.6 Fish and Wildlife Information Exchange (FWIE)
The national support center for the FWIE is attached to the Department of Fisheries
and Wildlife at Virginia Polytechnic and State University. With assistance from the U.S.
FWS and endorsements from a wide variety of natural resource agencies (including EPA)
and conservation groups, FWIE can provide States with the information to establish a
detailed data base system on the life histories and habitat requirements for most types
of fish and wildlife. States can then customize their systems in a variety of ways. Over
half the States are currently FWIE users. FWIE is building a consistent data base
structure for applications related to threatened and to endangered species and other
conservation biology projects.
7.6.7 National Center for Food and Agricultural Policy (NCFAP)
NCFAP has compiled a comprehensive data base of herbicide use in agricultural
crop production throughout the United States. The data base links usage estimates to
crop acreage estimates from the 1987 Census of Agriculture. Reports and data
summaries for this data base can be acquired on national, State, and local levels. The
reports contain background information, extensive tabular material, and source lists and
feature a comprehensive set of herbicide use profiles specific to their particular areas of
focus, ranging from a summary of herbicide-use data nationwide to county-specific uses
of particular active ingredients.
7.7 Contacts
Table 7-2 provides contacts for obtaining information discussed in Sections 7.2
through 7.6. The information presented in Table 7-2 is organized in the order that the
sources appeared in the chapter. For the National Agricultural Pesticide Impact
Assessment Program (NAPIAP), a complete list of representatives is presented in Table
7-3. Table 7-4 provides contact information for National Agricultural Statistics Service
(NASS) State Statisticians.
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Chapter 7
Table 7-2. Sources of Technical Information
AGENCY/SOURCE
PHONE NUMBER
CONTACT
Environmental Protection Agency
National Survey of Pesticides
Phase I Report
Phase II Report
Data Base
(703) 305-5805
(703) 487^600
(same as Phase I report)
(919) 541-2385
Office of Pesticide Programs
National Technical Information
Service
(same as Phase I report)
EPA National Computer Center
Pesticides Information Network
(703) 305-7187
User Support Staff
Comprehensive Conservation and
Management Plans
(202)260-1952
Oceans and Coastal Protection
Division
Nitrogen Action Plan
(202) 260-5484
Rob Wolcott
National Estuarine Program
Chesapeake Bay Program
1-800-523-2281
Nonpoint Source/Pesticides
Coordinator
Lorrie Roeser
or
Toxics Coordinator
Richard Batiuk
Clean Water Act
State Assessment Reports and
Management Plans
Nonpoint Source Program
Waterbody System
Section 304
Water Quality Criteria
NPDES
(202) 260-7040
(202) 260-7100
(202) 260-3667
(202) 260-5400
(202) 260-7166
Assessment and Watershed
Protection Division
Assessment and Watershed
Protection Division
Assessment and Watershed
Protection Division
Office of Science and
Technology
i
Office of Wetlands, Oceans,
and Watersheds
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Chapter 7
Table 7-2. Sources of Technical Information (continued)
AGENCY / SOURCE
Safe Drinking Water Act
Public Water Supply Program
Wellhead Protection
Sole Source Aquifer
UIC Program: Class V Wells
Comprehensive State Ground Water
Protection Program
FRDS
STORET
ORD Ground Water Research
Program Operation of CEAM
PRZM, DBAPE, etc.
FATE
Subsurface Processes
Fate and Transport Models for
Pesticides
Ground Water Monitoring for
Pesticides and Use of GIS for
Pesticide Management
Pollution Prevention Initiative
Ground Water Research
Publications
LISTS
AQUIRE
IRIS
TRIS
PHONE NUMBER
(800) 426-4791
(same as PWS Program)
(same as PWS Program)
(same as PWS Program)
(202) 260-7077
(800) 426-4791
(202) 260-7050
(706) 546-3549
(706) 546-3198
(405) 332-2224
(706) 546-3210
(702) 798-2598
(202) 260-3557
(513) 569-7562
(702) 798-2648
(218) 720-5564
(513) 569-7596
(202) 260-1531
CONTACT
Safe Drinking Water Hotline
(same as PWS Program)
(same as PWS Program)
(same as PWS Program)
Ground Water Protection Office
Safe Drinking Water Hotline
Office of Water
Louis Hoelman
Model Distribution Coordinator
Catherine Green
Heinz Kollig
Clint Hall
Bob Carsel
Joe Dlugosz
David Kline
Center for Environmental
Research Information
Head Librarian
Rose Randazzo Ellis
Christine L Russom
IRIS Manager
Pat Daunt
Office of Pollution Prevention
Lisa Capozzoli
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Chapter 7
Table 7-2. Sources of Technical Information (continued)
AGENCY / SOURCE
U.S. Department of interior
U.S. Geological Survey
NAWDEX
WATSTORE
RASA
GEOINDEX
PLUTO
Fish and Wildlife Service
Species Recovery Plans
Bureau of Land Management
Office of Surface Mining
Reclamation and Enforcement
Bureau of Reclamation
Bureau of Indian Affairs
U.S. Department of Agriculture
Agricultural Stabilization and
Conservation Service
Agricultural Research Service
(CREAMS and GLEAMS)
Cooperative State Research Service
National Agricultural Pesticide
Impact Assessment Program
(NAPIAP)
(I NAPIAP Special Projects
State Agricultural Experiment
Stations
PHONE NUMBER
- '.:...:__.... :;-.;/':- :,;"-.,. ..; -«:;;: >;
(703) 648-4302
(703) 648-5684
(same as NAWDEX).
(703) 648-5035
(703) 648-4380
(303) 236-1194
(703)358-2171
(202) 208-4896
(202) 208-2719
(202) 208-4442
(202) 208-4791
(202)720-2791
(202) 720-7333
(912)386-7173
(912) 386-3889
(202)401-4555
(202)401-4866
(202) 401-4555
CONTACT
(general information)
Water Resources Division
James Burton
(same as NAWDEX)
Office of Ground Water
William Alley, Chief of the Office
of Ground Water
Geologic Inquiries Group
Virginia Major
Geologic Division
Art Sutton
Division of Endangered Species
Robert Ruesink
Dr. John Fay
Deputy Assistant Director for
Land and Renewable
Resources
Kemp Conn
Office of Public Affairs
Technical Liaison Division
Judy Troast
Fred Hamann
(generarinformation)
Agricultural Conservation
Program
Soil Scientist, Ralph Leonard
Computer Programmer
Frank Davis
Dr.' Colien Hefferan, Acting
Refer to NAPIAP State contact
list (Table 4-3)
wiius wneeier
Dr. Colien Hefferan, Acting
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Chapter 7
Table 7-2. Sources of Technical Information (continued)
AGENCY / SOURCE
PHONE NUMBER
CONTACT
Extension Service
(202) 720-3029
Janet Pauly
or
contact the Director of your
State Cooperative Extension
Service
National Agricultural Library
AGRICOLA Data Base
CRIS Data Base
AQRIS Data Base
Water Quality Information Center
(301) 504-5479
(301) 504-5414
(same as CRIS)
(301) 504-6875
Reference desk
Information Services Branch
Robyn C. Frank
(same as CRIS)
(general information)
Forest Service
(202) 205-1473
National Forest System
Assistance, Watershed and Air
Staff
Soil Conservation Service
(202) 205-0026
(202) 720-1546
Office of Public Affairs
Judy Johnson
or
Contact State Conservationist
Economic Research Service
(202) 219-0433
Resource and Technology
Division,
Survey and Data Section
Merritt Padgitt
National Agricultural Statistics
Service
(202) 720-9579
Report Section,
Dissemination Group
George Patton
or
State Statistician
Farm-X\-Syst
(608) 262-0024
Farm-A-Syst Office
(general information)
NOAA
National Coastal Pollutant Discharge
Inventory (NCPDI)
Vulnerability Index
CZMA/Water Quality BMPs
(301) 713-3000
(same as NCPDI)
(202) 260-7110
National Ocean Service, Office
of Resource Conservation and
Assessment
Dan Farrow or Tony Part
(same as NCPDI)
EPA, Steve Dressing
Page 7-21
-------
Chapter 7
Table 7-2. Sources of Technical Information (continued)
AGENCY / SOURCE
Other Sources
Institute for Alternative Agriculture
USDA/ Alternative Farming Systems
Information Center
Land Stewardship Project
Conservation Technology
Information Center
National Fertilizer and
Environmental Research Center
National Pesticide Information
Retrieval Systems
Fish and Wildlife Information
Exchange
National Center for Food and
Agricultural Policy
PHONE NUMBER
(301) 441-8777
(301) 504-6559
(612) 433-2770
(317) 494-9555
(205)^386-2026
(317)494-6614
(703) 231-7348
(202) 328-5036
CONTACT
" :T-':
Neil Schaller
Jane Gates
Managing Director
George Booty
Water Quality Specialist
Lynn Kirschner
Ronald Ritschard
User Services Specialist
Virginia Walters
Project Leader
Jeff Waldon
Leonard Gianessi
Page 7-22
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives
STATE
CONTACT PERSON & ADDRESS
PHONE/FAX
Alabama
Dr. Harold Walker
Department of Agronomy & Soil
Auburn University
Auburn, AL 36849
Tel: 205-844-3994
Fax: 205-844-3945
Alaska
Mr. Wayne Vandre
Coordinator, Pesticide Programs
Cooperative Extension Service
2221 E, Northern Lights Boulevard
#11-8- -::':-:v .";: :; :'..-:..;,-'-;'
University of Alaska
Anchorage, AK 99508
Tel: 907-279-6575
Fax: 907^279-2139
Arizona
Dr. Paul Baker
Department of Entomology
College of Agriculture
1109 E. Helen Street
University of Arizona
Tucson, AZ 85719
Tel: 602-621-4012
Fax: 602-621-4013
Arkansas
Dr. Robert Frans
Altheimer Laboratory
Department of Agronomy
276 Altheimer Drive
University of Arkansas
Fayetteville, AR 72703
Tel: 501-575-3978
Fax: 501-575-3975
California
Mr. Rick Melnicoe
Department of Env. Toxicology
University of California
Davis, CA 95616
Tel: 916-752-7633
Fax: 916-752-2864
Colorado
Dr. Garry A. Mclntyre
Colorado State University
Dept. of Plant Pathology
Weed Science
Fort Collins, CO 80523
Tel: 303-491-1930
Fax: 303-491-0564
Connecticut
Candace Bartholomew
Pesticide Coordinator
1800 Asylum Avenue
University of Connecticut
West Hartford, CT 06117
Tel: 203-241-4940
Fax: 203-241-4790
Page 7-23
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives (continued)
STATE
CONTACT PERSON & ADDRESS
PHONE/FAX
Delaware
Dr. Susan Whitney
Extension Pesticide Coordinator
254 Townsend Hall
University of Delaware
Newark, DE 19717-1303
Tel: 302-831-8886
Fax: 302-831-3651
District of Columbia
Dr Mohammed S. Khan
University of the District of Columbia
901 Newton Street, N.E.,
Cooperative Ext. Service
Washington, D.C. 20017
Tel: 202-576-7419
Fax: 202-576-8712
Florida
Dr. Norman Nesheim
Pesticide Information Office
Building 847
University of Florida
Gainesville, FL 32611
Tel: 904-392-4721
Fax: 904-392-1988
Georgia
Dr. Keith Delaplane .
Department of Entomology
200 Barrow Hall
University of Georgia
Athens, GA 30602
Tel: 706-542-1765
Fax: 706-542-3872
Guam
Dr. Lee S. Yudin
Cooperative Extension Service
College of Agriculture & Life Science
University of Guam
Mangilao, GU 96923
Tel: 671-734-9139
Fax: 671-734-6842
Hawaii
Dr. Barry M. Brennan
Department of Environment - Biochemistry
Henke Building, Room 329
1800 East-West Road
University of Hawaii
Honolulu, HI 96822
Tel: 808-956-9208
Fax: 808-956-9675
Idaho
Dr. Gene P. Carpenter
Extension Pesticide Coordinator
University of Idaho i
Department of Plant, Soil, and Entomological
Science
Moscow, ID 83844
Tel: 208-885-7541
Fax: 208-885-7760
Page 7-24
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives (continued)
STATE
CONTACT PERSON & ADDRESS
PHONE/FAX
Illinois
Dr. David Pike
Department of Agronomy
1102 S. Goodwin
Turner Hall
University of Illinois
Urbana, IL 61801
Tel: 217-333-4424
Fax: 217-333-4949
Indiana
Dr. Fred Wnitford
Purdue Pesticide Program
Lilly Hall
Purdue University
West Lafayette, IN 47907
Tel: 317-494-4566
Fax:317-494-0363
Iowa
Dr. Wendy K. Wintersteen
Iowa State University
Extension Entomologist
111 Insectary Building
Ames, IA 50011-3140
Tel: 515-294-1101
Fax: 515-294-8027
Kansas
Dr. Donald C. Cress
Department of Entomology
Kansas State University
Manhattan, KS 66506
Tel: 913-532-5891
Fax: 913-532-6232
Kentucky
Dr. B.C. Pass
Department of Entomology
S-225 Agri. Science Building N
University of Kentucky
Lexington, KY 40546
Tel: 606-257-7450
Fax: 606-258-1120
Louisiana
Dr. Jerry B. Graves
Department of Entomology
402 Life Science Building
Louisiana State University
Baton Rouge, LA 70893
Tel: 504-388-1634
Fax: 504-388-1643
Maine
Dr. James Dill
UMCE-Pest Management Office
491 College Avenue
Orono, ME 04473
Tel: 207-581-3879'
Fax: 207-581-3881
Maryland
Amy Brown
Department of Entomology
University of Maryland
2322A Symons Hall
College Park, MD 20742
Tel: 301-405-3928
Fax:301-314-9290
Page 7-25
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives (continued)
STATE
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
CONTACT PERSON & ADDRESS
Dr. Patricia Vrttum
Pesticide Coordinator
Department of Entomology
Femald Hall
University of Massachusetts
Amherst, MA 01003
Dr. Larry Olsen
Pesticide Education Coordinator
11 Agriculture Hall
Michigan State University
East Lansing, Ml 48824-1039
Dr. Bh. Subramanyam
Department of Entomology
228 Hodson Hall
University of Minnesota
St. Paul, MN 55108
Edna Ruth Morgan
Pesticide Coordinator
Mississippi State University
Box 9661
Mississippi State, MS 39762
Dr. George Smith
Pest Management
45 Agriculture Building
University of Missouri
Columbia, MO 6521 1
Dr. Gregory D. Johnson i
Entomology Research Lab y:
324 Leon Johnson Hal! :
Montana State University ( ; ...';'.
Bozeman,MT 59717-0302 ;
Dr. Shripat Kamble
101 NRH Environmental Programs
University of Nebraska '
Lincoln, NE 68583-0818
Janet Usinger : ..; : , ; ; : : ";: ; .: : . : - ' ,;. ;'.<" Of " ' ;- \ :: . : :-.:;- "'
Nevada Cooperative Extension ;
University of Nevada/189 Mail Stop ;
Reno. NV 89557-0106
PHONE/FAX
Tel: 413-545-2283
Fax: 413-545-2115
Tel: 517-355-0117
Fax: 517-353-4995
Tel: 612-624-9292
Fax: 612-625-5299
Tel: 601-325-8601
Fax:601-325-8407
Tel: 314-882-4314
Fax:314-882-1469
Tel: 406-994-351 8
Fax:406-994-6029
:'-^;.-^'.'-:r;:-,:' :/:"-W
i
Tel: 402-472-6857
Fax: 402-472-8818
Tel: 702-784-1614
Fax: 702-784-6732
Page 7-26
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives (continued)
STATE
CONTACT PERSON & ADDRESS
PHONE/FAX
New Hampshire
Dr. James Bownan
Extension Entomologist
Nesmith Hall
University of New Hampshire
Durham, NH 03824
Tel: 603-862-1159
Fax: 603-862-1585
New Jersey
Dr. George C. Hamilton
Extension Pesticide Coordinator
108 J.B. Smith Hall
P.6: Box 231:.
Rutgers University
New Brunswick, NJ 08903
Tel: 908-932-9801
Fax: 908-932-7229
New Mexico
Dr. Michael English
Cooperative Extension
Program Leader
Box 3 AE
New Mexico State University
Las Cruces, NM 88003
Tel: 505-646-2546
Fax: 505-646-5975
New York
Dr. Donald Rutz
5123 Comstock Hall
Cornell University
Ithaca, NY 14583
Dr. Robert C. Seems
Department of Plant Pathology
NY Agricultural Experiment Station
Cornell University
Geneva, NY 14456-0462
Tel: 607-255-1866
Fax: 607-255-3075
Tel: 315-787-2366
Fax:315-787-2397
North Carolina
Dr. R.V. Leidy
Sciences Pesticide Residue Research Lab
3709 Hillsborough Street
Box 8604
North Carolina State University
Raleigh, NC 27607
Tel: 919-515-3391
Fax: 919-515-7169
North Dakota
Dr. John Nalewaja
Crop and Weed Sciences Department
Loftsgard Hall
North Dakota State University
Fargo, ND 27607
Tel: 701-237-8158
Fax: 701-237-7973
Page 7-27
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives (continued)
STATE
CONTACT PERSON & ADDRESS
PHONE/FAX
Ohio
Dr. Acie C. Waldron
NCRPIAP
Department of Entomology
1991 Kenny Road
Ohio State University
Columbus, OH 43210
Tel: 614-292-7541
Fax: 614-292-1687
Oklahoma
Dr. Jim T. Criswell
Pesticide Coordinator
127 NRC
Oklahoma State University
StiJIwater, OK 74078
Tel: 405-744-5531
Fax: 405-744-6039
Oregon
Dr. Jeff Jenkins
Department of Agri. Chemistry
Agricultural & Life Sciences Building
333 Weniger Hall
Oregon State University
Corvallis, OR 97331-7301
Tel: 503-737-5993
Fax: 503-737-5001
Pennsylvania
Dr. Winand K. Hock :
Director of the Pesticide Education Program
113 Buckhout Lab ;
Pennsylvania State University
University Park, PA 16802-4506
Tel: 814-863-0263
Fax: 814-863-7217
Puerto Rico
Dr. Nilsa M. Acin
Central Analytical & Pesticides Lab
Agricultural Experiment Station
P.O. Box21360
Rio Peidras, PR 00928
Tel: 809-756-6733
Fax: 809-768-5158
Rhode Island
Dr. Steven R. Aim
Department of Plant Sciences
316 Woodward Hall
University of Rhode Island
Kingston, Rl 02881
Tel: 401-792-5998
Fax:401-792-4017
South Carolina
Dr. Robert G. Bellinger
Department of EntomologyClemson Univ
Room 105, Long Hall
Box 340365
Clemson, SC 29634-0365
Tel: 803-656-5042
Fax: 803-656-5065
Page 7-28
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives (continued)
STATE
CONTACT PERSON & ADDRESS
PHONE/FAX
South Dakota
Larry Tidemann
Program Leader
Agriculture and Field Operation
AGH 152BBOX2207D
South Dakota State University
Brookings, SD 57007
Tel: 605-688-4147
Fax: 605-688-6347
Tennessee
Dr. Carroll J. Southards
University of Tennessee
Entomology & Plant Pathology
P.O. Box 1071
Knoxville, TN 37901
Tel: 615-974-7136
Fax: 615-974-4744
Texas
Dr. Rodney Holloway
Agronomy Field Laboratory #115
Texas A&M University
College Station, TX 77843-2474
Tel: 409-845-3849
Fax: 409-845-6251
Utah
Dr. Howard M. Deer
Utah State University
UMC-4620
Logan, UT 84322-4620
Tel: 801-750-1600
Fax:801-750-1601
Vermont
Dr. George B. MacCollom
Department of Plant & Soil Sciences
Hills Building
University of Vermont
Burlington, VT 05405-0082
Tel: 802-656-2630
Fax: 802-656-0285
Virgin Islands
Dr. Josef Keularts
V.I. Cooperative Extension Service
RR 02, Box 10000, Kingshill
St. Croix, Virgin Islands
USVI 00850
Tel: 809-778-0246
Fax: 809-778-8866
Virginia
Dr. Michael J. Weaver
Virginia Polytechnic Institute
Chemical, Drug & Pesticide Unit
139 Smyth Hall
Blacksburg, VA 24061-0409
Tel: 703-231-6543-
Fax: 703-231-4163
Page 7-29
-------
Chapter 7
Table 7-3. National Agricultural Pesticide Impact Assessment Program
List of State Liaison Representatives (continued)
STATE
Washington
West Virginia
Wisconsin
Wyoming
CONTACT PERSON & ADDRESS
Dr. Gary Long
Department of Entomology
166 FSHN
Washington State University
Pullman, WA 99164-6382
Dr. John F. Bariiecki
414 Brooks Hall
P.O. Box 6057
West Virginia University
Morgantown, WV 26506
Dr. Jeffery Wyman
Department of Entomology
1630 Linden Drive
University of Wisconsin
Madison, Wl 53706"
Dr. Mark Ferrell V
Dept. of Plant, Soil & Insect Sciences
College of Agriculture
Box3354 :
University of Wyoming
Laramie, WY 82071-3354
PHONE/FAX
Tel: 509-335-5504
Fax: 509-335-1009
Tel: 304-293^3911
Fax:304-293-2872
Tel: 608-262-3229
Fax: 608-262-3322
Tel: 307-766-5381
Fax: 307-766-5549
Page 7-30
-------
Chapter 7
Table 7-4. Contact Information for National Agricultural
Statistics Services (NASS) State Statisticians
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado ;
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maryland
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New England
New Jersey
Office Location ijYV*?
Montgomery
Palmer """.'' :. -V': :.'' :--->-!:-:-§
Phoenix
Little Rock
Sacramento
Lakewood ' ::'-:::::rV f "? %' ;
Dover
Orlando
Athens
Honolulu
Boise
Springfield
West Lafayette
Des Moines
Topeka
Louisville
Baton Rouge
Annapolis
Lansing
St. Paul
Jackson
Columbia ;
Helena
Lincoln
Reno
Concord, New Hampshire
Trenton
Phone Number
(205) 279-3555
<907) 745-4272
(602) 280-8850
; (501) 324-51 45
(916) 551-1533
(303)236-2300
(302) 739-481 1
<407) 648-601 3
(706) 546-2236
(808)973-9588
(208) 334-1507
(217) 492-4295
(317) 494-8371
(515)284-4340
(913)233-2230
(502)582-5293
(504) 922-1362
. (410)841-5740
(51 7) 377-1 831
(612)290-2230
(601)965-4575
; ; {314) 876-0950
(406) 449-5.303
{402) 437-5541
(702) 784-5584
(603) 224-9639
(609) 292-6385
Page 7-31
-------
Chapter 7
Table 7-4. Contact Information for National Agricultural
Statistics Services (MASS) State Statisticians (continued)
State
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
South Carolina
South Dakota
Tennessee
Texas
Utah
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Office Location
Las Cruces
Albany
Raleigh
Fargo
Columbus
Oklahoma City -
Portland
Harrisburg
Columbia
Sioux Falls
Nashville
Austin
Salt Lake City
Richmond
Olympia
Charleston
Madison
Cheyenne ;
Phone Number
(505) 522-6023
(518) 457-5570
(919) 856-4394
(701) 239-5306
(614)469-5590
(405) 525^9226 ;;
(503) 326-2131
(717)787-3904
(803) 765-5333
(605) 330-4235
(615) 781-5300
(512) 482-5581
(801) 524-5003
(804) 786-3500
(206) 902-1940
(304)558-2217
(608) 264-5317
: (307) 772-2181
7.8 References
Congress of the United States, OTA. 1390. Beneath the Bottom Line: Agricultural
Approaches to Reduce Aqrichemical Contamination of Groundwater. Circular 900.
OTA-F-418. NTIS PB91-129874. 34pp.
Daniel III, C.C. 1990. Evaluation of Site-Selection Criteria. Well Design. Monitoring
Technigues. and Cost Analysis for a Ground Water Supply in Piedmont Crystalline Rocks.
USG5 Water-Supply Paper 2341 -B. NTIS PB91 -154641.
Dumochelle, D.H., E.A. Lynch, and T.R. Cummings. 1990. A Literature Survey of
Information on Well Installation and Sample Collection Procedures Used in Investigations
of Ground Water Contamination by Organic Compounds. USGS Open-File Report 90-378.
Page 7-32
-------
Chapter 7
Fedkiw, John. 1991. Nitrate Occurrence in U.S. Waters (and Related Questions). A
reference summary of published sources from an agricultural perspective. National.
Agricultural Library. Call ATD427 N5F43. NTIS PB92-155696/GAR.
Frimpter, M.H., J.J. Donohue, IV, and M.V. Rapacz. 1990. A Mass-Balance Nitrate Model
for Predicting the Effects of Land Use and Ground Water Quality. USGS Open-File
Report 88-493.
Gibs, Jacob, I.E. Imbrigiotta, and Kenneth Turner. 1990. Bibliography on Sampling
Ground Water for Organic Compounds. USGS Open-File Report 90-564.
Hardy, M.A., P.P. Leahy, and W.M. Alley. 1989. Well Installation and Documentation, and
Ground Water Sampling Protocols for the Pilot National Water Quality Assessment
Program. USGS Open-File Report 89-396, .
Heath, R.C. 1989. Basic Ground Water Hydrology. USGS Water-Supply Paper 2220.
Jorgensen, D.G. 1989. Using Geophysical Logs to Estimate Porosity. Water Resistivity.
and Intrinsic Permeability. USGS Water-Supply Paper 2321.
Lapham, W.W. 1989. Use of Temperature Profiles Beneath Streams to Determine Rates
of Vertical Ground Water Flow and Vertical Hydraulic Conductivity. USGS Water-Supply
Paper 2337. NT1S PB179938.
Lohman, S.W. 1989. Ground Water Hydraulics. USGS Professional Paper 708.
National Agricultural Statistics Service and Economic Research Service. Agricultural
Chemical Usage: 1990 Field Crops Summary. 1991. ERS/NASS; telephone: 800-999-
6779.
USDA Soil Conservation Service. 1991. Screening Procedure for Soils and Pesticides
Relative to Potential Water Quality Impacts. SCS; telephone: 817-334-5422.
USDA Extension Service, Water Quality Initiative Team. July 1990. Bibliography:
Cooperative Extension System's Water Quality Education Materials.
t
USDA Extension Service, Water Quality Initiative Team. July 1990. Summary:
Cooperative Extension System's 1990 State Water Quality Projects. .
/
USDA National Agricultural Library. January 1982-July 1990. Managing Nonpoint
Sources of Pollution. Quick Bibliography Series. QB-91-50.
USDA National Agricultural Library. January 1982-July 1990. Monitoring Water for
Agricultural Wastes and Agrichemicals. Quick Bibliographic Series. QB 91 -52.
USDA National Agricultural Library. January 1982-July 1990. Regulating Water Quality:
Policy. Standards and Laws. Quick Bibliographic Series. QB 91-49.
Page 7-33
-------
Chapter 7
USDA National Agricultural Library. January 1985-July 1990. Allocation of Water
Resources. Quick Bibliography Series. QB-91-51.
USDA National Agricultural Library. January 1990-July 1991. Water Quality Implications
of Conservation Tillage. Quick Bibliography Series. Beltsville, MD. QB91-145.
U.S. EPA, Office of Ground Water and Drinking Water. 1991. Wellhead Protection
"Strategies for Confined Aquifer Settings. EPA 570/9-91-008.
U.S. EPA, Office of Ground Water and Drinking Water. 1991. Delineation of Wellhead
Protection Areas in Fractured Rocks. EPA 570/9-91 -008.
U.S. EPA, Office of Ground Water and Drinking Water. 1991. Protecting Local Ground.
Water Supplies Through Wellhead Protection. EPA 570/9-91-007.
U.S. EPA, Office of Ground Water and Drinking Water. May 1992. Definitions for the
Minimum Set of Data Elements for Ground Water Quality.
U.S. EPA, Office of Pesticide Programs. 1992. Integrating EPA's Agriculture and Water
Grant Programs.
U.S. EPA, Office of Ground Water Protection. 1985. Ground Water Monitoring Strategy.
NTIS PB-111886/AS. EPA 440/6-85-008.
U.S. EPA, Office of Ground Water Protection. 1987. An Annotated Bibliography of
Wellhead Protection References. NTIS PB88-148754/AS. EPA 440/6-87-014.
U.S. EPA, Office of Ground Water Protection. 1987. Ground Water Data Reguirements
Analysis. NTIS PB87-22532-AS. EPA 440/6-87-005.
U.S. EPA, Office of Ground Water Protection. 1987. Guidelines for Delineating Wellhead
Protection Areas. NTIS PB88-111430-AS. EPA 440/6-87-010.
U.S. EPA, Office of Ground Water Protection. 1987. Surface Geophysical Technigues for
Aguifer and Wellhead Protection Area Delineation. NTIS PB88-229505/AS. EPA 440/6-87-
016.
U.S. EPA, Office of Ground Water Protection. 1988. Developing a State Wellhead
Protection Program: A User's Guide to Assist State Agencies Under the Safe Drinking
Water Act. NTIS PB89-173751/AS. EPA 440/6-88-003.
U.S. EPA, Office of Ground Water Protection. 1988. Model Assessment for Delineating
Wellhead Protection Areas. NTIS PB88-231485/AS. EPA 440/6-88-002.
U.S. EFA, Office of Ground Water Protection. 1988. Protecting Ground Water:
Pesticides and Agricultural Practices. NTIS PB88-230628/AS. EPA 440/6-88-001.
Page 7-34
-------
Chapter 7
U.S. EPA, Office of Ground Water Protection. 1989. Indicators for Measuring Progress
in Ground Water Protection. EPA 440-6-88-006.
U.S. EPA, Office of Ground Water Protection. 1989. Wellhead Protection Program: Tools
for Local Governments. EPA 440/6-89-02.
U.S. EPA, Office of Ground Water Protection. 1990. Compendium of Federal Financial
Assistance Programs. Targeting Programs for State and Local Ground Water Protection.
EPA 440/6-90-008.
U.S. EPA, Office of Ground Water Protection. 1990. Hvdroaeoloaic Mapping Needs for
Ground Water Protection and Management: Workshop Report. EPA 440/6-90-002,
U.S. EPA, Office of Water. Undated. Office of Water Environmental and Program
Information Systems Compendium: Fiscal 1990. EPA 500/9-90-002.
U.S. EPA, Office of Water, Office of Ground Water Protection. 1988. Protecting Ground
Water: Pesticides and Agricultural Practices. EPA 440/6-88-001.
U.S. EPA, Office of Water, Office of Pesticides and Toxic Substances. 1990. National
Survey of Pesticides in Drinking Water Wells: Phase I Report. NTIS PB91-125765.
EPA 570/9-90-015.
U.S. EPA, Office of Water, Office of Pesticides and Toxic Substance. January 1992.
Another Look: National Survey of Pesticides in Drinking Water Wells: Phase II Report.
EPA 579/09-91-020.
U.S. EPA, Office of Research and Development, Environmental Research Laboratory.
October 1991. FATE: The Environmental Fate Constants Information System Data Base.
User's Manual. Version I-A. Center for Exposure Assessment Modeling, Athens, Georgia;
telephone: (404) 546-3770.
Utah State University and Cooperative Extension Service. Undated. Pesticide Data on
Potential Impacts to Ground Water and Surface Water.
Page 7-35
-------
va.ossary
GLOSSARY
Abiotic Degradation: Chemical decomposition brought about by physical or chemical processes.
Absorption: The passage of one substance into or through another; e.g., an operation in which one or
more soluble components of a gas mixture are dissolved in a liquid.
- ACP: Agriculture Conservation Program.
Action Levels: Reference points for response to (pesticide) contamination of ground water, set at
fractions of MCLs.
Adsorption: The adhesion in an extremely thin layer of molecules (as of gases, solutes, or liquids) to the
surfaces of solid bodies or liquids, with which they are in contact.
AGRICOLA: AGRICultural Online Access data base.
Agricultural DRASTIC: This method uses a relative ranking system for seven soil/aquifer parameters to
form, via an additive model, a continuous numerical index. The index is intended to represent the area's
relative degree of pollution potential by pesticides.
Agronomic: A branch of agriculture dealing with field crop production and soil management.
Ambient Monitoring: Monitoring to determine the background quality of groundwater.
Analytes: Chemicals tested for in an analysis.
Analytical Contaminant Transport Models: This type of model combines a two-dimensional analytical
model, to compute the time-varying distribution and dissipation of the pesticide DBCP in the plow layer,
with a one-dimensional numerical model to simulate both water and DBCP movement in a layer profile.
Aquifer: A subsurface, saturated geologic formation or group of formations capable of economically
yielding usable amounts of ground water from wells and springs.
Aquifer Recharge Areas: That portion of the drainage basin in which the net saturated flow of ground
water is directed away from the water table.
Aquifer Sensitivity: The intrinsic susceptibility of an aquifer to pesticide contamination. Sensitivity is
related solely to the hydrogeologic characteristics of the aquifer and the overlying geologic materials.
Sensitivities unrelated to agricultural practices, the degree of pesticide toxicity, and the nature of exposure,
if any, to human or other populations.
Aquifer Vulnerability: Susceptibility of an aquifer to contamination resulting from.the combined effects
of intrinsic sensitivity of the aquifer and the agricultural practices used. (
AQUIRE: Aquatic Toxicity Information Retrieval Data Base.
ASCS: Agricultural Stabilization and Conservation and Conservation Service.
Base Flexibility: Allows farmers who participate in the Federal commodity support programs to rotate
crops and plant a greater variety of crops on acres that were previously tied to specific crop.
Baseline Monitoring: Measurement of ground water quality, used to establish quality of the ground water
in a given aquifer prior to the onset of activities that may alter the water quality.
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Glossary
Biodegradation: Chemical degradation brought about by living organisms.
Biological Pest Control: Agricultural techniques used to enhance natural mechanisms that can control
pests at economically tolerable threshold levels. Techniques include use of antagonists, predators, self-*
defense mechanisms, parasites, and insect pathogens.
Biotic: Pertaining to life or specific life conditions.
BMP: Best Management Practices are methods or measures designed to prevent or reduce ground water
contamination from pesticides.
BPJ: Best Professional Judgment.
California's Hot Spot: This ground water vulnerability assessment method utilizes information on
sensitive areas including depth to ground water, soil texture, and annual precipitation or irrigation. The
overlay maps for each available factor are stacked to determine sensitive areas. After preliminary
screening of sensitive areas, quantitative field investigations are taken to further define and verify sensitive
areas.
Carcinogen: Any substance that can cause or contribute to the production of cancer.
C&T: Certification and Training programs for pesticide applicators.
Catalyst: A substance that initiates a chemical reaction and enables it to proceed under different
conditions than otherwise possible.
CEAM: Center for Exposure Assessment Modeling.
CES: Cooperative Extension Service. .
CFR: Code of Federal Regulations.
CLP: Superfund's Contract Laboratory Program.
Chemigation: The practice of mixing pesticides or fertilizers with irrigation water and applying the mixture
to cropped fields.
CMIS: Chemical Movement in Soil considers a 60-cm root zone and calculates the amount of pesticide
leaching past that depth for any given time.
Chronic Toxlclty: The capacity of a substance to cause long-term poisonous human health effects.
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Contaminant: Any physical, chemical, biological, or radiological substance or matter that has an adverse
effect on air, water, or soil.
Contour Plowing: Practice of plowing along the contour of the land in order to inhibit erosion. The
practice also inhibits travel of pesticides to surface waters.
CREAMS; GLEAMS: These models evaluate the effects of .agricultural management practices on
transport of pesticides in the root zone, and describe rainfall, infiltration, and runoff process. Pesticide
degradation, volatilization, ana plant uptake are aiso included in the models.
Crop Rotation: The successive planting of different crops in the same field over a period of years.
Increases the health of crops by controlling multi-year buildup of crop-specific pests, thus decreasing the
need to use pesticides.
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Glossary
Cross-Compliance Measures: Semivoluntary measures associated with compliance incentives.
CZMA: Coastal Zone Management Act of 1972, enforced through the National Oceanic and Atmospheric
Agency.
DBAPE: Data Base Analyzer Parameter Estimator.
Degradation: The breakdown of a pesticide into reaction products, generally of less complex form.
Degradation Rate: The rate of which a pesticide is broken down to a less complex form.
Detection: The discovery of the presence of a ground water constituent during monitoring for indicator
parameters, specific pesticides, or pesticide reaction products.
Detection Limits: Concentration values below which the instrument is unable to measure presence of
the analyte. .
Discriminant Statistical Analysis/Soil Taxonomy and Surveys: This method uses a multivariation
statistical approach (Fisher's Linear Discriminant analysis) with soil taxon units to delineate sensitive areas.
The method utilizes soil survey reports, the U.S. rectangular coordinate system, and available ground
water pesticide analyses data.
Ecosystem: The interacting system of a biological community and its non-living environmental
surroundings.
EPA: U.S. Environmental Protection Agency.
Epidemiologic: The sum of factors controlling the presence or absence of a disease or pathogen.
ERS: The Economic Research Service of the U.S. Department of Agriculture.
Estuarine: Pertaining to a water passage where the tide meets a river current.
ETU: Ethylene Thiourea. A pesticide metabolite.
Evaluation/Effectiveness Monitoring: Observation and testing of ground water quality to determine the
effectiveness of an SMP in preventing ground water contamination.
Evapotranspiration: The sum of evaporation plus transpiration.
FDA: Federal Drug Administration.
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FIFRA: Federal Insecticide, Fungicide, and Rodenticide Act.
Filter Pack: Clean uniform sand or gravel that is placed in a well between the borehole wall and the well
screen to prevent formation material from entering the screen.
Foliar application: The treatment of plant surfaces with pesticides.
FRDS: Federal Reporting Data system.
Fungicide (chemical): Agent that destroys fungi or inhibits their growth.
FWS: Fish and Wildlife Service.
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Glossary
GC/MS: Gas chromatography/Mass Spectroscopy.
Geology: A science that deals with the history of the earth and its life, especially as recorded in rocks.
Geomorphic: Of or relating to the form of the earth or a celestial body (as the moon) or its solid surface
features.
GIS: Geographic Information System.
GLPs: Good Laboratory Practices. Standards for testing conducted in the fie field and for such
disciplines of testing as ecological effects, chemical level, and residue chemistry. These standards are
regulated under-FIFRA.
Ground Water: The supply of fresh water found beneath the Earth's surface, usually in aquifers, which
is often used for supplying wells and springs. Because ground water is a major source of drinking water.
there is growing concern over areas where leaching agricultural or industrial pollutants or substances from
leaking under ground storage tanks are contaminating ground water.
GSMP: Generic State Management Plan.
GUS: Ground Water Ubiquity Score. This method calculates an index which is a numerical scale dividing
pesticides into non-leachers, transrtionals, and leachers. The GUS index is based on curve fittings
between pesticide half lives and soil organic-carbon partitioning coefficients of three groups of pesticides.
HA: Health Advisory (see HAL).
Headspace: The empty volume above the liquid in a container.
Health Advisory Level (HAL): The levels of chemical concentration in water that are acceptable for
drinking.
Herbicide: An agent used to destroy or inhibit plant growth.
Hydraulic Conductivity: The rate of flow of water in gallons per day through a cross section of one
square foot under a unit hydraulic gradient, at the prevailing temperature (gpd/ft2). In the SI System, the
units are m3/day/m2 or m/day.
Hydraulic Gradient: The rate of change in energy contained in a water mass that is produced by
elevation, pressure or velocity, or per unit of distance of flow in a given direction.
Hydrogeologic: Refers to the interrelationships of geologic materials and processes with water, especially
ground water.
Hydrolysis: A chemical process of decomposition involving splitting a bond and adding the elements of
water.
Immunoassay: An assay procedure that utilizes a limited number of binding sites on an antibody to
measure the amount of antigen (analyte) in the sample.
Integrated Pest Management (IPM): A pest population management system that anticipates and
prevents pests from reaching damaging levels by using techniques such as natural enemies, pest-
resistant plants, cultural management, and judicious use of pesticides. A mixture of pesticide and non-
pesticide methods to control pests. IPM reduces total pesticide use while economically controlling pest-
reduction efforts and maintaining the economic yield of the protected crop(s).
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Glossary
IPM/ICM: Integrated Pest and Crop Management.
IRIS: Integrated Risk Information System.
Irrigation: Technique for applying water or wastewater to land areas to supply the water and nutrient
needs of plants.
Karst Topography: Refers to areas of sink holes, caves, and streamless valleys. A type of geographic
terrain underlain by carbonate rocks where significant solution of the rock has occurred due to flowing
ground water.
teachability: The ability of a pesticide to percolate downward from the top soil layer.
Leachability Classes of Kansas Soils: This method was used to group Kansas soils into four classes
of susceptibility based on the soil profile and water infiltration rate (permeability).
Leaching: The process by which soluble constituents are dissolved and carried down through the soil
by a percolating fluid.
LEACHMP: A finite-difference model for simulating the fate of pesticides in the unsaturated zone during
a single growing season. The model simulates the effects of layered soils, precipitation/
evaportranspiration cycles, plant growth, and the transport of multiple metabolites as well as parent
pesticides
Lithology. The macroscopic character of a rock formation.
LUD: Limited Use Designation.
MCL: Maximum Contaminant Level.
MCLGs: Maximum Contaminate Level Goals.
MDLs: Method Detection Levels.
MECP: Michigan Energy Conservation Program.
Metabolite: A substance derived from the breakdown of a pesticide by microorganisms.
Microbe: A microorganism, bacteria, or fungus.
Monitoring: Periodic or continuous surveillance or testing to determine the level of compliance with
statutory requirements and/or pollutant levels in various media or in humans, animals, and other' living
things.
MOUSE: A set of mathematical models for tracing the transport and fate of pesticides in the unsaturated
and saturated zones. It is used as a preliminary management tool in different soil-climate management
regimes. MOUSE has four submodels: (1) Climatic data generator; (2) vadose zone at balance; (3)
vadose zone solute transporter; and (4) aquifer water and solute transporter.
MSFWIS: Multi-State Fish and Wildlife Information Systems.
Multimedia: Affecting more than one environmental medium (e.g., ground water, surface water, soil, or
air).
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Glossary
Multiple Regression Statistical Analyses: This multiple regression method was used to describe results
of existing ground water contamination and factors affecting that contamination with six study areas in'
Nebraska. The researchers focused on nine independent variables including: hydraulic gradient;
hydraulic conductivity; specific discharge; depth to water; well depth; annual precipitation; soil
permeability; irrigation-well density, and annual nitrogen fertilizer use.
MWRA: Massachusetts Water Resources Authority.
NAL: National Agricultural Library.
NAPIAP: National Agricultural Pesticide Impact Assessment Program.
NASS: National Agricultural Statistics Service.
NAWDEX: National Water Data Exchange.
NCPDI: National Coastal Pollutant Discharge Inventory.
NEP: National Estuarine Program.
NFEDC: National Fertilizer and Environmental Development Center.
NFERC: National Fertilizer and Environmental Research Center.
Nitrate: A compound containing nitrogen which can. exist in the atmosphere or as a dissolved gas in
water and which can have harmful effects on humans and animals. Nitrates in water can cause severe
illness in infants and cows.
NOAA: National Oceanic and Atmospheric Administration.
Nonpoint Source Pollution: Contamination (of groundwater) originating from a wide area, not from well-
defined locations, a mobile or dispersed source of pollutants. Examples: acid rain deposition and
contamination of surface water by salting roads; automobiles.
NPIRS: National Pesticide Information Retrieval System.
NPS Programs: Nonpoint Source Programs.
Nutrients: Organic and inorganic materials in soil that provide nourishment to plants.
OGWDW: EPA's Office of Ground Water and Drinking Water.
ORD: EPA's Office of Research and Development.
OPP: EPA's Office of Pesticide Programs.
Permeability: Water infiltration rate. (The rate at which liquids pass through soil or other materials in a
specified direction.)
PESTANS I: One-dimensional, steady-State model that is limited to projecting vertical movement through
the unsat'jrated zone.
PESTANS II: A two-dirnensicna! numerical model that simulates both horizontal and vertical movement
through the unsaturated zone.
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Glossary
Pesticide: Substance or mixture of substances intended for preventing, destroying, repelling, or
mitigating any pest. Also, any substance or mixture of substances intended for use as a plant regulator,
defoliant, or desiccant.
Pesticide Fate: The end point of a pesticide or other contaminant after all processes have influenced it,
including transport and degradation.
Pesticide Half-Life: The amount of time it takes for one-half of an amount of a pesticide to degrade.
Pesticide Transport: Movement of a pesticide through the environment, and the means by which it
moves.
pH: Measure of the acidity or alkalinity of a solution.
Phreatic: In the zone of saturation.
Piezometer: Basic field device for measurement Of hydraulic head (energy contained in a water mass,
produced by elevation, pressure, or velocity), a tube or pipe in which the elevation of a water level can
be determined. Piezometers are usually installed in groups so that they can be used to determine the
direction of ground water flow.
PMZs: Pesticide Management Zones (California).
Polarity: Attraction toward a particular object or in a specific direction. The quality or condition inherent
in a body that exhibits opposite properties or powers in opposite parts of directions or that exhibits
contrasted properties or powers in contrasted parts or direction.
ppb: Parts per billion.
PQLs: Practical Quantitation Limits.
Prevention: Measures taken to control application or release of chemicals so as to minimize the chance
of potential harmful effects to humans or the environment through contamination of a resource, such as
ground water or surface water.
PRZM: A one-dimensional, finite-difference, pesticide transport model based on a pesticide mass-balance
equation to evaluate leaching from the root zone under field crops. PRZM requires inputs of hydrology,
crop, pesticide and oil information as well as daily meteorological data.
PSMP: Pesticide State Management Plan.
QAO: Quality Assurance Officer.
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QAPPs: Quality Assurance Program Plans and/or Quality Assurance Project Plans.
QA/QC: Quality Assurance/Quality Control. QA functions are management tools that are independent
of technical organization. QC functions are the integral activities within technical support projects that are
designed to assure or control data precision and accuracy.
Quantification Limit: Level at which a concentration can be measured.
RASA: Regional Aquifer Systems Analysis Program. '.
Remediation: The process of reducing the harmful effects of contamination incidents.
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Glossary
Residue: Amount of a pollutant remaining in the environment after a natural or technological process has
taken place, e.g., the sludge remaining after initial wastewater treatment, or paniculate remaining in air
after the air passes through a scrubbing or process.
Response: Actions initiated after a pesticide is detected in ground water.
Rodentlclde: An agent (chemical) that kills, repels, or controls rodents.
Run-off: That part of precipitation, snow melt, or irrigation water that runs off the land into streams or
other surface-water. It can carry pollutants from the air and land into the receiving waters.
RUSTIC: A union of the PRZM, VADOFT, and SAFTMOD models.
SAFTMOD: Two-dimensional, finite-element, flow and transport model for saturated flow below the water
table. . . ;
Saturated Zone: The underground area in which water fills all of the available spaces.
Scouting: The inspection of a field for pests,
SCS: Soil Conservation Service.
SCWA: Suffolk County Water Authority, in New York.
SDWA: Safe Drinking Water Act.
Seep: A spot where a fluid (as water, oil, or gas) contained in the ground oozes slowly to the surface and
often forms a pool.
SEEPAGE: This method uses a relative ranking system, for seven soil/aquifer paraments. Continuous
numerical indexes called Site Index Numbers (SINs) are calculated for different areas and compared to
determine the degree of aquifer sensitivity.
Silviculture: Tree farming.
Sinkhole: A natural depression on the land surface, generally occurring in limestone regions and formed
by solution of rock or collapse of a cavern roof.
Siting Controls: Regulations on the location of potential sources of (ground water) contamination.
SMP: State Management Plans.
Soil Organic-Carbon Partitioning Coefficients: Soil adsorption coefficient normalized for the soil organic
carbon content.
Soil Profile: A vertical section of the soil through all its horizons and extending into the parent material.
Soii Structure: The combination or arrangement of primary soil particles into secondary particles, units,
or peds.
Soil texture: The relative proportion of the various soil separates in a soil (saw, silt, and clay).
SOP: Standard Operating Procedures.
Sorption: To take up and held by either adsorption or absorption.
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Glossary
SPISP: Soil-Pesticide Interaction Screening Procedure. This method determines the relative potential loss
of a specific pesticide by surface runoff or by leaching below the. root zone. Rates both soil potential and.
pesticide potential to leach. Ratings are used in leaching matrix format where potential 1 has a high
probability of being lost via leaching; potential 2 has the possibility of being lost via leaching (but not as
great as potential 1) and potential 3 has very low probability of being lost by leaching.
Spring: A source of water issuing from the ground.
States' Comprehensive State Ground Water Protection Philosophy: The ground water protection
philosophy defines the waters to be considered in prevention, monitoring, and response plans.
STORET: Storage and retrieval of U.S. Waterways Parametric Data System.
Stratification: To divide into a series of graded strata.
Stratigraphic Setting: Layering of soils and rocks in a particular area.
Strip-Cropping: Growing crops in a systematic arrangement of strips or bands which serve as barriers
to wind and water erosion.
TAD: Technical Assistance Document.
Topography: The physical features of a surface area including relative elevations and the position of
natural and man-made features.
Toxic: Harmful to living organisms.
TRIS: Toxic Chemical Release Inventory System.
TVA: Tennessee Valley, Authority.
TWC: Texas Water Commission.
Unsaturated Zone: The underground area below the soil layers but above the vadose zone and the
water table in which water does not fill the available spaces.
Uptake: An act or instance of absorbing and incorporating especially into a living organism.
USDA: United States Department of Agriculture.
USGS: U.S. Geological Survey.
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VADOFT: One-dimensional, finite-element, flow and transport model which simulates the flow from the
bottom of the root zone to the top of the water table.
Vadose Zone: The underground zone containing water above the zone of saturation.
VIP: Uses numerical solution algorithms and nonequilibrium kinetics to describe the behavior of
pesticides in the unsaturated zone and predict mass transport o the atmosphere and ground water.
VISA: Very Intensely Studied Area (Florida).
Volatility: Description of any substance that evaporates readily.
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Glossary
Washington's Map Overlays: This method determined sensitive areas by preparation of overlay maps
for three hydrogeologic factors (presence of shallow water-table aquifers, high soil permeability, and
intense irrigation). Visual inspection was used to quickly determine the sensitive areas and non-sensitive
areas. The sensitive areas were then traced on 1:500,000 scale maps.
Watershed: A region or area bounded peripherally by a water parting and draining ultimately to a
particular watercourse or body of water.
Water table: The level of ground water.
WATSTORE: National Water Storage and Retrieval System.
Well: A bored, drilled, or driven shaft, or a dug hole, whose depth is greater than the largest surface
dimension and whose purpose is to reach underground water supplies or oil, or to store or bury fluids
below ground. , .
Well Casing: A solid piece of pipe, typically steel or PVC plastic, used to keep a well open in either
unconsolidated materials or unstable rock.
Well Seal: Low-permeability material that is emplaced to fill the annular space around a well.
Wellhead: The land-surface and subsurface area surrounding a water-supply well.
WHPAs: Wellhead Protection Areas.
Wisconsin's Ground Water Susceptibility Project: This method uses five hydrogeologic factors to
determine ease of contaminant migration trough overlying materials to the ground water. These factors
are depth to bedrock, type of bedrock, soil characteristics, depth to water table, and characteristics of
surficial deposits. Each of the five factors' maps is put into digital form and overlaid to produce a
composite map.
WSTB: Water Science and Technology Board.
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