States Water Quality Methods and Data Comparability Board:
Creating a framework for collaboration and comparability
C.A. Peters*, H.J. Brass**, and J. Diamond***
*U.S. Geological Survey, WRD, 8505 Research Way,
** U.S. Environmental Protection Agency, OGWDW,
26 W. Martin Luther King Drive, Cincinnati, OH
*** Tetra Tech Inc., 10045 Red Run Blvd., Suite
110, Owings Mills, MD 21117
Each year, government agencies, industry, academic
researchers, and a wide variety of private organizations in the
United States devote enormous time and several billion dollars
to the monitoring, protection, and restoration of water resources
and watersheds. Critical differences in project design, methods,
data analysis, and data management have often made it difficult
for monitoring information to be shared by other potential data
users. In the absence of a focused effort to ensure consistent
and comparable data, and a means to determine the utility of a
data set for a particular use, there is considerable redundancy
and inefficiency in water assessments. The Methods and Data Comparability
Board is a partnership of water quality experts from federal agencies,
states, tribes, municipalities, industry, academia, and private
organizations. It is chartered under the National Water Quality
Monitoring Council, whose mission is to coordinate, and provide
guidance on, implementation of the voluntary, integrated, nationwide
monitoring strategy developed by its predecessor - the Intergovernmental
Task Force on Water Quality Monitoring (ITFM, 1995a). The Board
provides the framework and the forum for comparing, evaluating,
and promoting monitoring approaches that can be implemented in
all appropriate water quality monitoring programs.
Each year, government agencies (local, state, tribal,
and federal), industry, academic researchers, and a wide variety
of private organizations in the United States devote enormous
amounts of time and several billion dollars to the monitoring,
protection, and restoration of water resources and watersheds.
This work includes:
monitoring the status
and trends in water quality
and emerging water-quality issues
designing and implementing
resource management programs
with regulatory programs
The information gathered through these activities
is certainly useful to the data collectors themselves, however,
critical differences in project design, methods, data analysis,
and data management often make it difficult for monitoring information
to be shared by other potential data users. Accurate, cost-effective
and efficient assessment of the nations water resourceswithin
and among watersheds requires that monitoring entities work
collaboratively and strive for comparability in methods and data
management. The design and implementation of assessment and management
programs should be a cooperative product of the various monitoring
agencies and organizations active in any given watershed. Knowing
whether the water quality monitoring methods used and the data
they produce are comparable is essential to achieving the goals
of the Clean Water Action Plan (USEPA/USDA, 1998).
METHODS AND DATA COMPARABILITY FRAMEWORK
Producing comparable data is dependent on the use
of a coordinated monitoring framework that includes four primary
elements: developing data and measurement quality objectives for
each monitoring activity, determining the performance of sample
collection protocols, determining the performance of field and
laboratory methods, and utilizing a standard data reporting approach
to provide methods information (figure 1). The National Method
and Data Comparability Board (Board) activities described in this
report have been developed to address specific method and data
comparability issues for each of the primary elements of the overall
monitoring process. The Boards strategic philosophy is to
complete ongoing products in the short term, while continuing
to develop its longer-term goals and objectives. The short-term
emphasis is to marshal Board resources to successfully complete
projects, so that accomplishments and success stories can be demonstrated.
A longer-term view includes the development of tools for the monitoring
community through the use of pilot tests and other studies.
Data Quality Objectives (DQOs) and Measurement
Quality Objectives (MQOs) are or should be the foundation of all
monitoring studies, as these define the questions needing answers
and the data quality needed to answer those questions (USEPA 1994;
ITFM 1995b; MDCB 1999a and b). DQOs are statements that define
the confidence required in conclusions drawn from data produced
by a project (USEPA 1994). The USEPAs DQO process is a
7-step strategic planning approach that is used to define what,
how, when, and where data are collected and analyzed to ensure
that the type, quantity, and quality of environmental data used
in decision making will be appropriate for the intended application
(USEPA 1994). For example, the USEPAs Office of Ground
Water and Drinking Water used the DQO process to help ensure that
water quality measurement data and engineering information gathered
under their Information Collection Rule (ICR) were adequate to
support development of a series of drinking water regulations
regarding surface water treatment requirements and disinfectant
and disinfection byproduct controls (RTI, 1995). MQOs are statements
that contain specific units of measure such as percent recovery,
percent relative standard deviation, or detection level. They
should be thoroughly specified to allow specific comparisons of
data to a MQO.
Field Sampling and Monitoring
Monitoring data are obtained by field sampling,
direct field measurements, and remote sensing. The Board recognizes
that field method performance is an area in need of attention,
as sampling-induced error or biases can be larger than those associated
with laboratory analysis (ITFM 1995c). One of the key concepts
inherent in the Boards mission is the use of a performance-based
system (PBMS) approach. The Board defines a PBMS as a framework
that permits the use of any appropriate sampling or analytical
technology that demonstrates the ability to meet established performance
criteria and complies with specified DQOs and MQOs of the project.
Most monitoring samples are currently analyzed
using prescriptive methods. The widespread use of prescriptive
methods will undoubtedly continue in the future, however, a performance-based
systems approach, if effectively designed and implemented, could
provide the framework for ensuring better, faster, safer, or less
expensive analytical methods that provide comparable data. A
PBMS approach recognizes the need for well-defined DQOs and MQOs,
an adequate supply of reference materials, the need for validated
or reference methods that meet the stated MQOs, and the need for
Additionally, to ensure comparable data of known quality, it is
critical to standardize laboratory quality systems. Standardization
of quality systems is particularly important for nation-wide monitoring
programs in which data from a variety of organizations are used
to make large-scale assessments. A key component for ensuring
quality systems is third party accreditation of laboratories that
provide environmental data. Accreditation is defined as a formal
recognition of competence that a laboratory can perform specific
tests, or types of tests.
Data to Include Methods Information
ability for a user to judge the comparability of monitoring data
is dependent on the availability of information about which methods
were used to obtain the data, information about the performance
of those methods, and the inclusion of metadata and data quality
documentation reported with the data. The Board recognizes that
better documentation of existing methods, and more complete and
consistent metadata reporting by monitoring organizations, will
improve our ability to define and use comparable data for a variety
METHODS AND DATA COMPARABILITY BOARD APPROACH
The Board includes 5 federal, 5 state or tribal,
and 5 private sector delegates and an equal number of alternates
from each of those sectors. The Board accomplishes its objectives
through Workgroups that include Board delegates, alternates and
other volunteer experts in the water-quality field. These Workgroups
define and specify goals, benchmark associated efforts, coordinate
with other groups working toward similar objectives, and develop
guidance for the monitoring community. Where appropriate and
feasible, pilot studies and work agreements with the private sector
and other collaborative efforts are encouraged to enhance communication
and use of comparable monitoring methods.
have been developed to focus on specific methods and data comparability
issues. Some of the Workgroups have a more inherent product focus
(NEMI, WQDEs, Outreach), others have both a product and a process
focus (Accreditation, PBMS), while still others have a primarily
discipline-based focus (Nutrients, Biology). The discipline focused
Workgroups are also involved in product development, however,
much of their effort will go towards providing information to
the product and process focused Workgroups. The Outreach workgroup
integrates across all work groups using a liaison member approach.
In addition to these more formalized Workgroups the Board has
also been available to review and participate in the development
of other related technical activities in a more ad hoc fashion.
The Board meets quarterly, however, the Workgroups
conduct much of their business between the Board meetings via
conference calls and electronic mail. A steering committee meets
via conference call between Board meetings to coordinate funding,
conference calls, integration efforts, and to provide overall
focus and direction to the Workgroups. The full Board meets via
conference calls between Board meetings to provide progress reports
on product task force efforts and to discuss operational issues.
Current Workgroups and their specific objectives
Performance Based Systems (PBMS)
Inform the Board
and the National Water Quality Monitoring Council (Council) on
technical matters pertaining to the implementation of a PBMS.
Define the dimensions of a PBMS for field chemical, microbiological,
and biological protocols and laboratory analyses and prepare guidelines
to implement PBMS in ambient and compliance monitoring. The workgroup
provides peer review of and coordination with PBMS development
efforts being undertaken by other organizations.
National Environmental Methods Index (NEMI)
Provide a web-based
searchable compendium containing chemical, physical, radiochemical,
microbiological and biological field and laboratory methods, including
protocol summaries and information. It will allow the rapid communication
and comparison of critical parameters of methods for use with
methods selection and (or) methods modification and data comparability.
Laboratory and Field Accreditation
accreditation and develop a Board position on federal laboratory
accreditation and pre-laboratory certification in order to establish
a uniform national accreditation process including the use of
performance-based systems (PBMS). Coordinate the accreditation
related activities of the various Board workgroups and communicate
those efforts to the corresponding workgroups in the National
Environmental Laboratory Accreditation Conference (NELAC) in order
to avoid duplication of effort. NELACs purpose is to establish
and promote mutually acceptable performance standards for the
operation of environmental laboratories.
Data Elements (WQDE)
recommend a "core" set of data elements for reporting
water quality monitoring results, to be voluntarily implemented,
that would allow data to be compared regardless of, but recognizing,
the purpose of the monitoring activity.
and develop a framework for characterizing and comparing water
monitoring efforts that diagnose environmental conditions using
either: a) whole organisms; b) biomolecular materials; c) populations
in the field; or d) microbiology. Develop pilot tests of the PBMS
position guidelines and information for the NEMI database.
and develop a framework for characterizing and comparing nutrient
methods and data. Develop nutrient pilot tests of the PBMS position
guidelines and information for the NEMI database. Coordinate these
efforts with the EPA regional nutrient criteria strategy.
implement means to inform and solicit input from the water resources
community regarding the efforts of the Board. Employ various media,
including: the internet, brochures, fact sheets, reports, posters,
and conference presentations. Develop methods comparability sessions
and workshops for the biannual National Water Quality Monitoring
Conference. Develop a coordinated outreach approach for the Board
Workgroups and with the Council.
One of the key
concepts inherent in the Boards mission is the use of a
performance-based system approach. Key aspects of a PBMS were
identified in an issue paper developed by the Board entitled Towards
a Definition of a Performance Based Approach to Laboratory Methods
(MDCB, 1999a). Important elements include: a) the need to establish
concise measurement quality objectives (MQOs) and data quality
objectives (DQOs) for each parameter reported; b) the need for
demonstrated methods capable of meeting these MQOs or DQOs; c)
the need for adequate reference materials to assist laboratories
in demonstrating the appropriateness of a given method (prescriptive
or performance-based); d) the need for laboratories to adequately
document method performance, and e) the successful completion
of a pilot program to demonstrate the advantages and viability
of a performance-based approach. The paper addresses the issues
and concerns regarding the use of PBMS, and defines the dimensions
of a PBMS focusing on laboratory, but also addressing field
aspects. It includes chemical, microbiological and biological
protocols used in compliance and ambient monitoring programs.
The Board believes that setting data-quality objectives and using
PBMS to meet these objectives will promote and enhance innovative
technologies without compromising data quality. Data users can
determine data comparability and make their own decisions concerning
the applicability of data to fit a particular need. Performance
criteria, such as precision, bias, sensitivity, specificity, and
detection limits, used in conjunction with reference methods,
will be integral to the implementation of PBMS and will provide
the user with "judgment" factors for decision-making.
If implemented successfully, the use of PBMS is a move towards
the production of valid, scientific procedures and evaluations,
and away from a prescriptive regulatory mandate.
Environmental Methods Index (NEMI) will ensure that the consideration
of analytic methods is a more active part of the planning and
implementation of monitoring programs. NEMI will include data
fields for comparison such as, relative cost, sample preparation,
instrumentation required, method detection level, sampling information,
sample preservation and storage conditions, bias, precision, and
other QA/QC requirements. Typical users of NEMI are expected to
include regulators, regulated parties, scientists, volunteer monitoring
groups, and watershed planning organizations. The Workgroup developed
a list of critical methods parameters that relate to analytes,
instrumentation, matrices, interference, sampling, sample handling,
and data quality. These critical parameters will be developed
for a list of 100 methods that were chosen to represent a wide
range of organizations as well as method type.
The Board completed
a study to determine if the information available on nutrient
methods from four sources (APHA 1995, ASTM 1989 and 1999, and
USGS (Fishman), 1993) were sufficient to populate the NEMI data
fields. Descriptive information for 25 desired NEMI fields was
compiled from 26 nutrient methods from these 4 sources. Findings
included: Information is readily available for 15 of the fields,
information is predominantly not available for 6 fields,
and information availability for the other 4 fields is variable.
and Publicity Workgroup
The Board developed
sessions and workshops at each of the first two National Water
Quality Monitoring Conferences - Monitoring: Critical Foundations
to Protect Our Waters (NWQMC, 1998) and Monitoring for
the Millennium (NWQMC ,2000). Sessions included: QA/QC for
monitoring programs; data comparability and collection methods;
and inorganic, organic, and biological methods comparability.
Workshops were held on PBMS and Water Quality Data Elements. Additionally,
as a part of its outreach effort, the Board has developed and
published two Fact Sheets, entitled: The National Methods
and Data Comparability Board: Collaboration and Comparability
(MDCB, 1998) and Why is a National Environmental Methods
Index Needed? (MDCB, 2000a); established an internet site
(MDCB, 1999b); prepared a portable display that provides an overview
of the Boards efforts (MDCB, 2000b); prepared articles for a variety
of newsletters; and made presentations and prepared papers (Brass
1998, 1999, 2000) for numerous conferences and meetings.
The Board provided
oversight and guidance for the development and implementation
of methods comparability projects. These projects included: A
Comparison of Water-Quality Sample Collection Methods Used by
the U.S. Geological Survey and the Wisconsin Department of Natural
Resources (Kammerer, 1998); A Reconnaissance for
Sulfonylurea Herbicides in Waters of the Midwestern USA
(Battaglin, 1998a and 1998b, Scribner 1998); and a review of the
USGS-EPA Drinking Water Initiative (Patterson, 1997).
One of the technical
challenges in implementing a PBMS is defining a rigorous, yet
cost-effective framework by which laboratories can document that
method performance has been achieved. To address this challenge,
the MDCB has designed and is coordinating a pilot study that evaluates
the method verification process, within a PBMS framework. The
pilot study examines a new method for analyzing carbonaceous oxygen
demand (COD) that does not generate hazardous waste (mercury),
evaluating with respect to the current prescriptive COD method.
The study is testing and evaluating an analytical and statistical
protocol that will reasonably and efficiently demonstrate: (a)
laboratory competence with the method; (b) that the new method
performance is appropriate for the matrices of interest; and (c)
that laboratory performance is maintained. The pilot makes use
of two different approaches that have been advocated for PBMS:
(1) a DQO approach that relies on data quality objectives as reference
criteria upon which to judge method comparability and (2) a reference
method approach in which method performance and comparability
is judged relative to the performance of an already established
and validated method (Eaton, 1999).
is being developed in three phases. The first phase is expected
to be completed by December 2000 and will include the 100 methods
chosen to test the approach to developing a data dictionary, business
rules, user requirement rules, and design using an ORACLE database
structure. The second phase, expected to be completed July 2001,
will incorporate reviewer comments of Phase 1, include about 250
additional methods, and will create the functional, web-enabled
NEMI database. Phase 3 includes updating methods in the database
and adding additional laboratory methods and field protocols on
an ongoing basis.
agencies have laboratories that evaluate water quality. The samples
are collected for a variety of reasons and are analyzed by a variety
of methods. There is considerable variability in the quality control
standards implemented by the laboratories, based on the data quality
objectives. An issue paper is being developed to assist federal
laboratories in making an informed decision regarding the relevance
of national accreditation for various water testing objectives.
The paper summarizes the range of purposes for which various federal
laboratories conduct water testing and delineates the analytical
services in which these laboratories are engaged. The paper reviews
several key elements in considering which accreditation program
best suits the accreditation needs of federal laboratories. Key
elements considered in this evaluation include national or international
authority, reliance on generally accepted accreditation standards
such as ISO 25 or ISO 17025, and state recognized reciprocity.
The issue paper also explores current laboratory accreditation
standards available for consideration as candidates for the implementation
of a national accreditation program. The Workgroup is also providing
a review of the proposed privatization of the USEPA performance
documentation of method performance characteristics is essential
for appropriate application of environmental sampling and analysis
methods, and interpretation of results. One of these characteristics,
method precision, is important for establishing and evaluating
measurement quality objectives (MQOs). Further, quantification
of method precision is necessary to develop data quality objectives
(DQOs) for program design and assessment. Similarly, the sensitivity
of a method provides an indication of the responsiveness of an
indicator to the stressor or stressors of concern. There are
a variety of statistical methods that can be used to assess the
precision and sensitivity of a method. The Board has developed
a draft issue paper (MDCB, in press) describing procedures for
documenting precision of field collection methods for stream benthic
macroinvertebrates. This paper specifies several ways in which
the precision of a given field collection method can be determined
and uses case study data derived from several areas of the United
States. Many of these field methods are currently used in the
U.S., however, their performance is largely unknown or undocumented
(Barbour, 1999). The lack of known data quality from these field
methods has hampered attempts to assess biological quality on
a national scale (e.g., state 305(b) assessments; USEPA/USDA 1998).
Core data element
lists for reporting chemical and microbiological water quality
monitoring results have been developed. The core data elements
were developed to be compatible with the major existing water
quality databases. The core lists are continuing to be reviewed
by the water quality monitoring community. The lists will be discussed
during regional public meetings that will be announced
in the Federal Register.
The Board is
providing review of two activities: 1) an appendix on nutrient
methods that is a part of the Regional Nutrient Criteria Strategy
for Streams and Rivers (USEPA in review); 2) an intercomparison
exercise for nutrients in seawater that is being conducted by
The National Research Council (NRC) of Canada (NOAA 2000).
The Board will develop a framework to characterize
the performance and determine the comparability of field sampling
methods. Pilot studies will be developed to examine field sampling
methods for nutrients and stream benthic macroinvertebrates.
These pilots will represent collaborations among several organizations
(federal, state, and private) and will rely on the DQO process
to establish appropriate methods and measurement quality needed.
The Board will collaborate with the Water Environment Research
Foundation (WERF) and EPA to provide peer review on the development
of DQOs and the selection of appropriate methods for validating
laboratory effluent toxicity tests using field biological assessments.
The Board will develop consensus issue papers on
other aspects related to PBMS implementation. These may include:
status and needs for reference material availability, liability
issues, a national framework for accrediting laboratories, training
required to implement PBMS, and develop a how to guide
for conducting pilot tests. To ensure comparable implementation
of a PBMS, the Board will study the need for a national program
to accredit field personnel who provide environmental data.
The Board will
work to develop a NEMI biological methods database that is searchable
and provides summaries of performance characteristics for biological
methods and that could be used to determine comparability of different
biological methods. The biological methods database will include
laboratory and field methods that span taxonomic levels. Types
of methods currently being considered include: (1) cellular and
molecular (e.g., immunoassays), (2) whole organism (e.g., Microtox,
algae, invertebrates), (3) microbiological activity/count (e.g.,
fecal coliform, Cryptosproridia), and (4) field population/community
sampling and assessment (e.g., benthic invertebrates). Methods
will be searchable by: type of method,source of method,type of
matrix (e.g., freshwater, saltwater,
tissue),type of organism (and species if appropriate), and by
type of quality control requirements. The biological methods
NEMI will be linked with other appropriate on-line databases provided
by consensus organizations, and federal and state agencies to
ensure that current method updates are included. The information
obtained during the development of the NEMI biological methods
database will be useful for developing the business rules and
data dictionary needed to include chemical and physical sampling
protocols in NEMI.
The Board will
compile relevant information produced by several agencies to develop
concrete, hands-on guidance on developing DQOs, translating those
DQOs into MQOs, and choosing appropriate methods using real-world
examples from the water quality monitoring field. A expert-system
based front-end user interface will be developed for NEMI
to guide a user to the appropriate field protocol or analytical
laboratory method to satisfy user defined DQOs and MQOs. The user
interface will be developed so that it can be incorporated into
any on-line expert system that the National Water
Quality Monitoring Council may develop.
The Board will
develop core data element lists for reporting monitoring data
from biological, chemical, and physical field sampling, field
measurements, and remote sensing.
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