United States
Environmental Protection
Agency
Office of Modeling,
Monitoring Systems and
Quality Assurance (RD-680)
Washington DC 20460
Research and Development
EPA/600/9-90/001 January 1990
Environmental
Monitoring and
Assessment Program
Overview
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Overview
This document presents an overview of the rationale, goals, and primary elements of the En-
vironmental Monitoring and Assessment Program (EMAP), which represents a long-term com-
mitment to assess and document periodically the condition of the Nation's ecological resourc-
es. EMAP is being designed by the U.S. Environmental Protection Agency's (EPA) Office of
Research and Development. The program will serve a wide spectrum of users: decision-makers
who require information to set environmental policy; program managers who must assign pri-
orities to research and monitoring projects; scientists who desire a broader understanding of
ecosystems; and managers and analysts who require an objective basis for evaluating the effec-
tiveness of the Nation's environmental policies.
Monitoring, Regulatory, & Policy Needs
Environmental regulatory programs have been estimated to
cost more than $70 billion annually, yet the means to assess
their effect on the environment over the long term do not ex-
ist. While regulatory programs are based upon our best un-
derstanding of the environment at the time of their develop-
ment, it is critical that long-term monitoring programs be in
place to confirm the effectiveness of these programs in
achieving their environmental goals and to corroborate the
science upon which they are based.
The EPA, the U.S. Congress, and private environmental or-
ganizations have long recognized the need to improve our
ability to document the condition of our environment. Con-
gressional hearings in 1984 on the National Environmental
Monitoring Improvement Act concluded that, despite consid-
erable expenditures on monitoring, federal agencies could as-
sess neither the status of ecological resources nor the overall
progress toward legally-mandated goals of mitigating or pre-
venting adverse ecological effects.. In the last decade, articles
and editorials in professional journals of the environmental
sciences have repeatedly called for the collection of more rel-
evant and comparable ecological data and easy access to
those data for the research community.
Affirming the existence of a major gap in our environmen-
tal data and recognizing the broad base of support for better
environmental monitoring, the EPA Science Advisory Board
(SAB) recommended in 1988 that EPA initiate a program that
would monitor ecological status and trends, as well as devel-
op innovative methods for anticipating emerging problems
before they reach crisis proportions. EPA was encouraged to
become more active in ecological monitoring because its reg-
ulatory responsibilities require quantitative, scientific assess-
ments of the complex effects of pollutants on ecosystems.
EMAP is being initiated in 1990 by EPA in response to these
recommendations.
EMAP's Purpose
EMAP is being designed to monitor indicators of the condi-
tion of our Nation's ecological resources. Specifically, EMAP
is intended to respond to the growing demand for informa-
tion characterizing the condition of our environment and the
type and location of changes in our environment. Simultane-
ous monitoring of pollutants and environmental changes will
allow us to identify likely causes of adverse changes. When
fully implemented, EMAP will answer the following ques-
tions:
Q What is the current status, extent, and geograph-
ic distribution of our ecological resources (e.g.,
estuaries, lakes, streams, wetlands, forests, grass-
lands, deserts)?
Q What proportions of these resources are degrad-
ing or improving, where, and at what rate?
Q What are the likely causes of adverse effects?
Q Are adversely-affected ecosystems responding as
expected to control and mitigation programs?
EMAP will provide the Administrator, the Congress, and
the public with statistical data summaries and periodic inter-
pretive reports on ecological status and trends. Because
sound decision-making must consider the uncertainty asso-
ciated with quantitative information, all EMAP status and
trends estimates will include statistically-rigorous confidence
limits.
Assessments of changes in our Nation's ecological re-
source conditions require data on large geographic scales
collected over long periods of time. For national assessments,
comparability of data among geographic regions (e.g., the
Northeast, Southeast, and West) and over extended periods is
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critical, and meeting this need by simply aggregating data
from many individual, local, and short-term networks that are
fragmented in space or time has proven difficult, if not impos-
sible. EMAP will focus specifically on national and regional
scales over periods of years to decades, collecting data on in-
dicators of ecological condition from multiple ecosystems
and integrating them to assess environmental change. This
approach, along with EMAP's statistically-based design, dis-
tinguishes it from most current monitoring efforts, which tend
to be short-term or locally-focused. A long-term, integrated,
multi-ecosystem monitoring program offers the advantages of
earlier detection of problems and improved resolution of
their extent and magnitude, while enabling formulation of
more cost-effective regulatory or remedial actions.
Environmental monitoring data are collected by EPA to
meet the requirements of a variety of regulatory programs.
Many federal agencies collect environmental data specifical-
ly to manage particular ecological resources. Efficient execu-
tion of EPA's mandate to protect the Nation's ecosystems re-
quires, therefore, that EMAP complement, supplement, and
integrate data and expertise from the regulatory offices within
EPA and from other agencies. EMAP should not be perceived
as a substitute for ongoing programs designed to meet objec-
tives other than its own. Interagency coordination is actively
being pursued with the Departments of Interior, Commerce,
and Agriculture. This coordination avoids duplicative moni-
toring efforts, facilitates exchange of existing data for use in
the refinement of monitoring networks, and increases the ex-
pertise available to quantify and understand observed status
and trends. EMAP will also draw upon the expertise and ac-
tivities of the EPA Regional Offices, States, and the interna-
tional community.
Ecological monitoring programs of the 1990's and beyond
must be able to respond and adapt to new issues and per-
spectives within the context of a continuing effort to detect
trends and patterns in environmental change. These demands
will be met by EMAP through a flexible design that can ac-
commodate as yet undefined questions and objectives as
well as changing criteria of performance and scientific capa-
bility. Further, EMAP's design will encourage analysis, re-
view, and reporting processes that foster discovery of unan-
ticipated results and promote the widespread dissemination
of scientifically-sound information. Periodic evaluations of
the program's direction and emphasis will be the key to
maintaining its viability and relevance while retaining the
continuity of the basic data sets. These evaluations will serve
to preclude the "aging" that typically hinders long-term moni-
toring efforts.
Planning & Design
The major activities in 1990 around which EMAP is being
developed are:
G Indicator Evaluation and Testing—evaluation and
testing of indicators of ecological condition;
Q Network Design—design and evaluation of inte-
grated, statistical monitoring networks and proto-
cols for collecting status and trends data on indi-
cators;
G Landscape Characterization—nationwide charac-
terization of ecological resources in areas within
the EMAP sampling network to establish a base-
line for monitoring and assessment; and
G Near-Coastal Demonstration Project—imple-
mentation of regional-scale surveys to define the
current status of our estuarine resources.
Although the goal is to establish the program in all categc
ries of ecosystems, the initial emphasis is on testing and im
plementing the program in estuaries, near-coastal wetlands
and inland surface waters, coSrdinating these activities witl
the National Oceanic and Atmospheric Administration, tb
U.S. Fish and Wildlife Service, and the U.S. Geological Sur
vey. Because precipitation and air quality are two importan
factors influencing ecosystems, EMAP also will contribute t<
the evaluation and maintenance of the multia'gency atmos
pheric deposition networks currently coordinated by the Na
tional Acid Precipitation Assessment Program (i.e., the Na
tional Trends Network/National Dry Deposition Network)
These ecosystems and deposition networks offer immediaK
opportunities to demonstrate the EMAP approach.
EMAP also will contribute to the development of a re
search program in environmental statistics. This program wil
refine the statistical framework for the remaining types o;
ecosystems in preparation for full implementation of EMAF
in 1995 and beyond. Relying heavily on expertise from aca
demia and industry, this program will develop methods and
approaches for: (a) analyzing and interpreting spatial and
temporal trends in indicators across regions; (b) incorporating
and substituting historical data and data from ongoing moni-
toring programs into EMAP; (c) designing efficient quality as-
surance programs for ecological monitoring programs; and
(d) diagnosing the likely causes of adverse conditions in eco-
systems.
Indicator Evaluation & Testing
Purpose
EMAP will evaluate and use indicators that collectively de-
scribe the overall condition of an ecosystem. Measurements
of ecosystem condition should reflect characteristics clearly
valued by society. Measurement methods must be standard-
ized and quality-assured so that spatial patterns and temporal
trends in condition within and among regions can be accu-
rately assessed.
Strategy
Indicators in three categories will be evaluated:
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Q Response indicators—which quantify the re-
sponse of ecosystems to anthropogenic stress. Ex-
amples include signs of gross pathology (e.g., the
appearance of tumors in fish or visible damage to
tree canopies); the status of organisms that are
particularly sensitive to pollutants or populations
of organisms important to sportsmen, commercial
interests, or naturalists; and indices of community
structure and biodiversity.
Q Exposure indicators—which show whether
ecosystems have been exposed to pollutants, hab-
itat degradation, or other causes of poor condi-
tion. Examples include ambient pollutant concen-
trations; acidic deposition rates; bioaccumulation
of toxics in plant and animal tissues;
media-specific field bioassays using test organ-
isms; and measurements of habitat condition or
availability (e.g., siltation of bottom habitat and
vegetative canopy complexity).
G Stressor indicators—which are socio-economic,
demographic, and regulatory compliance meas-
urements that are suggestive of environmental
stress. Examples include coal production, popula-
tion figures, pesticide applications, pollutant
emissions inventories, and land use.
Sets of indicators will be identified and measured in all cat-
egories for each ecosystem type. The set of response indica-
tors should reflect adverse effects of both anticipated and un-
anticipated environmental stresses (e.g., new pollutants).
Criteria must be developed for each response indicator to
identify when conditions change from acceptable or desira-
ble to unacceptable or undesirable. Criteria could be based
on conditions attainable under best management practices as
observed at "regional reference sites", relatively undisturbed
sites that are typical of an ecoregion. A set of exposure indi-
cators will be used to determine whether ecosystems have
been exposed to environmental stress and what the causes of
poor condition are likely to be. For example, undesirably low
diversity in stream fish communities across a region might be
related to the presence of toxics in sediments, siltation of bot-
tom habitat, insufficient flow, low pH, or bioaccumulation of
toxics. In this example, stressor indicators that might be ex-
amined in diagnosing the cause would include the number
and type of industrial dischargers, farmed acreage or con-
struction activity, water withdrawals, presence of mine spoils
or acidic deposition, and regional pesticide application.
The goals of EMAP are quite different from those of the
compliance monitoring most commonly conducted by EPA.
While compliance monitoring involves identifying, with a
high degree of confidence, pollutant concentrations that can
be linked unequivocally to individual polluters, EMAP will
use sets of indicators to assess the condition of multiple eco-
logical systems across regions, coupled with an evaluation of
associated pollutant sources or other anthropogenic environ-
mental disturbance. EMAP's regional approach to environ-
mental monitoring and assessment is quite unusual, and the
expected benefits include an improved capability to detect
emerging problems and to identify those types of ecosystems
most in need of research, assessment, or remediation. Re-
gional monitoring and assessment is the only effective way to
determine whether current environmental regulations are ad-
equately protecting our ecological resources.
Activities
Many scientific questions remain to be answered. Is the
natural variability in response indicators too large to make
sufficiently precise estimates of regional conditions? Can eco-
system condition be compared among regions with differing
biota? What criteria will be used to determine acceptable ver-
sus unacceptable conditions? How are the data best interpret-
ed for systems with response indicators in undesirable ranges
and multiple, conflicting, or unknown exposure indicators?
What, if anything, might be done when a system's range in
response indicators is acceptable, but the range in exposure
indicators is not? EMAP will seek short- and long-term an-
swers to these questions through three types of activities:
Q Reports evaluating the availability and applicabili-
ty of indicators for all EMAP ecosystem
categories;
Q Workshops on ecological indicators; and
Q Development of a long-term indicator research
program for all EMAP ecosystem categories.
Network Design
Purpose
Meeting the goal of estimating status and trends in the con-
dition of the Nation's ecosystems requires a monitoring
framework that:
Q Provides the basis for determining and reporting
on ecological indicators at various geographic
scales;
Q Is adaptable to monitoring on regional as well as
on continental and global scales;
Q Enables the examination of correlations among
spatial and temporal patterns of response,
exposure, and stressor indicators;
G Enables the incorporation or substitution of data
from ongoing monitoring sites and networks; and
G Is sufficiently adaptable and flexible to accommo-
date changes in spatial extent of the resource
(e.g., the areal extent of wetlands) and to address
current and emerging issues.
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Strategy
A global grid will be constructed for identifying sampling
sites. This grid will then be divided into sub-grids in accor-
dance with whatever scale of resolution (e.g., national, re-
gional, or subregional) is required for an assessment of the
condition of ecological resources. Currently, a sub-grid for
the United States and its surrounding continental shelf waters
that includes approximately 12,500 sites is being evaluated.
Within these sites, ecosystems will be identified and charac-
terized and their their number and areal extent will be deter-
mined. This initial characterization will be accomplished us-
ing existing maps, satellite imagery, and aerial photography.
Field sampling of sets of indicators will be conducted on a
subset of sites statistically selected from the 12,500 original
sites.
Current EMAP research will determine the number of sam-
pling sites needed for regional and national reports on the
status, changes, and trends in indicators. Two alternative ap-
proaches for field sampling of approximately 3,000 sites are
being considered. In the first, about one-fourth of the 3,000
sites across the continental United States would be visited in
one year. The following year, a second one-fourth of the sites
would be sampled and so on, such that all sites would be vis-
ited during a four-year period. In the second, data would be
collected during a single year at all the sampling sites in a ge-
ographical area (e.g., the estuaries in the Virginian Province
from Cape Cod to Cape Hatteras or all lakes and streams in
the Northeast) and sampling efforts would shift to a new area
during following years. The statistical, logistical, and report-
ing advantages of each option are being evaluated in light of
EMAP's long-term goal to provide a national assessment of
the status, changes, and trends in ecological resources. In ad-
dition, the timing of the sampling period, the statistical proce-
dures for establishing where a measurement is to be made,
and the number of samples that must be collected at each
sampling site are being examined.
Activities
Current activities are focused on making the global grid fi-
nal, applying it to the United States, and identifying rules for
associating ecosystems with grid points and statistically se-
lecting them for sampling. The EMAP design and sampling
strategy will be reviewed by the American Statistical Associa-
tion and appropriate ecosystem experts.
Landscape Characterization
Purpose
National assessments of status and trends of the condition
of ecosystems require knowing not only what percentage of a
particular resource is in desirable or acceptable condition,
but also how much of that resource exists. Some types of wet-
lands are being lost at an alarming rate; conversion and loss
of other types of ecosystems are also occurring. Such changes
may be of particular concern if statistically correlated wi
pollutant exposure or other anthropogenic stressors. For me
ecosystems, few national data bases can currently be used
derive quantitative estimates of ecosystem extent and chan
es in condition on a regional basis with known confidence.
The technique that will be used to address these issues
landscape characterization. Landscape characterization is th
documentation of the principal components of landscap
structure—the physical environment, biological compositioi
and human activity patterns—in a geographic area. EMA
will characterize the national landscape by mapping lam
scape features (e.g., wetlands, forests, soils, and land uses) i
areas associated with the EMAP sampling grid. Characteriz.
tion uses remote sensing technology (satellite imagery an
aerial photography) and other techniques (e.g., cartographi
analysis and analysis of census data) to quantify the exter
and distribution of ecosystems. Over time, periodic aerij
and satellite photography will permit quantitative estimatio
of changes in landscape features that might be related to an
thropogenic activities and pollutants. The results of thes
characterization analyses also permit more informed selec
tion of systems for field sampling.
Strategy
The characterization strategy involves the application of re
mote sensing technology to obtain high-resolution data on se
lected sample sites and lower resolution data over broad geo
graphical areas. Other data sources such as maps ant
censuses will be used to supplement the remote sensing data.
The remote sensing data also will furnish detailed informa
tion needed for the network design. For example, lakes
streams, wetlands, forests, and other types of ecosystems as
sociated with each grid point will be identified so that a sub
set for field sampling can be statistically selected. Character!
zation also supplies a portion of the data needed to classify
ecosystems into subcategories of interest (e.g., forest-covei
types, wetland types, crops, and lake types).
Certain types of landscape data assist in diagnosing the
probable causes of undesirable conditions in response indica-
tors. Characterization will describe the physical and spatial
aspects of the environment that reflect habitat modification,
for example, those that can amplify or counteract the effects
of toxicants and other pollutants on plants and animals.
Finally, characterization will compile data on stressor indi-
cators that can be identified from remote sensing and
mapped data, including land use, mining activities, popula-
tion centers, transportation and power corridors, and other
anthropogenic disturbances.
EMAP will assemble, manage, and update these data in
Geographic Information System (CIS) format. A standardized
characterization approach and a landscape information net-
work common to all ecosystems will be used to optimize cost
and data sharing and to ensure common format and consis-
tency. Through close work with other agencies, EMAP will
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establish design requirements for the integrated characteriza-
tion including acceptance criteria for baseline data, consis-
tent classification detail and accuracy, and suitable spatial
and temporal resolution to distinguish landscape features of
particular interest.
Activities
The design of the characterization plan and the evaluation
of potential characterization techniques are in progress. A
prototype methodology for high-resolution characterization
nas been developed. Current activities include evaluating a
range of methods, from landscape ecology to quantitative,
multistage remote sensing (combined satellite and aerial pho-
tography) in widely different terrain types. EMAP characteri-
zation will begin in 1990 at approximately 800 sites, or
about one-fourth of the 3,000 selected for field sampling.
Near-Coastal Demonstration Project
Purpose
Information obtained from the near-coastal demonstration
project will be used to refine the EMAP design, and the study
itself will serve as a model for implementing EMAP projects
in other study areas and types of ecosystems.
The demonstration project has five goals:
G Evaluate the utility, sensitivity, and applicability
of the EMAP near-coastal indicators on a regional
scale;
Q
G
Determine the effectiveness of the EMAP network
design for quantifying the extent and magnitude
of pollution problems in the near-coastal em
environ-
ment-
Demonstrate the usefulness of results for plan-
ning, priority-setting, and determining the
effectiveness of pollution control actions;
Q Develop standardized methods for indicator
measurements that can be transferred to other
study areas and made available for other
monitoring efforts; and
Q Identify and resolve logistical issues associated
with implementing the network design.
Strategy
The strategy for accomplishing the above tasks is to work
closely with the National Oceanic and Atmospheric Adminis-
tration's National Status and Trends Program to field-test the
near-coastal indicators and network design through a demon-
stration study in the estuaries and coastal wetlands of the
Mid-Atlantic area of the United States. Estuaries were select-
ed because their natural circulation patterns concentrate and
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retain pollutants. Estuaries and coastal wetlands are also
spawning and nursery grounds for many valued living re-
sources, and estuarine watersheds receive a large proportion
of the pollutants discharged to the Nation's waterways. The
Mid-Atlantic study area was chosen because adverse pollu-
tant impacts are evident; contaminants are present in the wa-
ter, sediments, and biota; the vitality of many organisms is re-
portedly threatened; and seven of the area's larger estuaries
are included in EPA's National Estuary Program.
Activities
During 1989, the major environmental problems associat-
ed with near-coastal systems were identified: eutrophication,
contamination, habitat modification, and the cumulative im-
pact of multiple stressors. A set of response, exposure, and
stressor indicators applicable to each problem is to be identi-
fied, based on current understanding of how various environ-
mental stressors affect ecosystem processes and biota. Near-
coastal ecosystems have been classified for monitoring and
assessment based on their physical and chemical characteris-
tics and their susceptibility to environmental stressors. A
monitoring network design that is compatible with the EMAP
design is being developed. Several logistical and technical
questions regarding the EMAP near-coastal project remain,
including:
Q What set of indicators will be measured?
Q What specific methods will be used to sample
each indicator?
G Will all indicators be measured at all sampling
sites or can a sampling plan be developed that re-
quires measurement of costly indicators only at
selected sites? and
Q To what degree should sources of variation be
measured and accounted for in the network
design?
The near-coastal demonstration project will be conducted
in the estuaries and coastal wetlands of the mid-Atlantic area
of the United States (from Cape Hatteras to Cape Cod) during
mid-1990. A report on the results of the project will be pre-
pared in 1991.
Information Contact
EMAP is planned and managed by ORD's Office of Model-
ing, Monitoring Systems, and Quality Assurance (OMMSQA).
Inquiries may be directed to:
EMAP Director
ORD/OMMSQA (RD-680)
U.S. EPA
Washington, DC 20460
(202)382-5767
Fax: (202)252-0929
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