United States
Environmental Protection
Agency
Washington, D.C. 20460
September 1982
CHESAPEAKE
BAY PROGRAM:
EXECUTIVE SUMMARY

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FOREWORD
In July of 1975, the Senate.Committee on Appropriations
directed the Environmental Protection Agency (EPA) to conduct
an in-depth study of Chesapeake Bay and complete the following
tasks:
o Assess the principal factors having an adverse impacc
on the environmental quality of Chesapeake Bay.
o Analyze all environmental sampling data presently
being collected on Chesapeake Bay.
o Establish a continuing capability for collecting,
storing, analyzing, and disseminating such data,
o Institute a sampling program.
o Determine what units of government have management
responsibility for the environmental' quality of
Chesapeake Bay.
o Review ways to improve existing Chesapeake Bay
management mechanisms and new alternatives.
This summary highlights the technical findings, describes
related benefits, and explains how the information will be
used. The last task is addressed in the management study which
will be transmitted under separate cover.
The reports attached to this summary are:
o Chesapeake' Bay:	Introduction to an Ecosystem—explains
important ecological relationships,
o A Summary of Chesapeake Bay Program Technical Studies: A
Synthesis—summarizes and explains the technical knowledge
gained from the research projects funded by this Program in
the areas of. nutrient enrichment, toxic substances, and
submerged aquatic vegetation,
o Chesapeake Bay Program: Technical Project Summaries-—
announces the availability of technical research projects
from the National Technical Information Service and
presents summaries of each.
During the next phase of the program, EPA Region III will
expand on the original tasks. EPA will relate the scientific
findings on water quality in the Chesapeake Bay to shifts in
living resources in the Bay in an attempt to characterize the
past and present state of the Bay. These relationships will be
presented in Chesapeake Bay Program: A Profile of
Environmental Change. EPA will also identify potential control
alternatives for point and non-point sources of pollutants and
begin to examine management structures or systems which could ~
most effectively implement recommendations.

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TECHNICAL FINDINGS
Research conducted on the Bay through EPA Chesapeake Bay
Program (CBP) grants was designed to increase our knowledge in
three priority problem areas: nutrient: enrichment, toxic
chemicals, and declining submerged aquatic vegetation (SAV).
These areas were selected in October 197 7 by representatives
from Virginia, Maryland, EPA, the Bay scientific community, and
citizen/user groups. This group identified ten major areas of
environmental quality concern for the Bay, and in subsequent
meetings established the three priority areas. Work plans were
designed and implemented by EPA through grants to Bay research
insititutions. Technical guidance was provided from this point
to grant completion, by teams of scientists who monitored
progress to assure that the research was on target.
A Program Management System was designed to show the
milestones and timelines necessary to relate the basic research
products to the final program products. The plan, used in
conjunction with the Project Tracking System, enabled EPA
Region III managers to both maintain a perspective of the
relationships of each grant to the end products and, at the
same time, monitor progress of each grant and contract.
NUTRIENT ENRICHMENT
Nutrient enrichment has changed the Bay's water quality.
Over the past 20 years, certain areas have become nutrient
enriched showing algal blooms and containing low levels of
oxygen and light. These effects vary in their intensity and
are controlled by season, the movement of nutrients in the
estuary, and the chemical form in which they appear. An
objective of the Program was to identify and understand the
sources of nutrient enrichment and nutrient processes to help
the States and EPA better manage water quality and resources.
Key findings to date include:
o The upper Bay, mid Bay, and several major western and
eastern shore tributaries are either severely or
moderately nutrient enriched compared to historic
trends.
o Nonpoint sources, predominantly agricultural cropland,
are a major significant source for nutrient
enrichment, particularly nitrogen (N).
o Point sources are the major source of phosphorus (P)
for severely enriched areas,
o Major rivers such as the James, Potomac, and
Susquehanna are important contributors of nutrients,
metals, and toxic compounds,
o The lower Bay has remained relatively'unaffected by
nutrient enrichment.
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o Organic material, such as algae, can accumulate in the
water column, causing decreased transparency, and
decreased levels of dissolved oxygen. Decreased
transparency can inhibit photosynthesis by plants and
sight feeding by fish. Decreased levels of dissolved
oxygen can cause some living organisms to suffocate,
o Both nitrogen and phosphorus enter the Bay from the
¦atmosphere, fluvial or nonpoint sources, point
sources, sediments, and the ocean.
TOXIC SUBSTANCES
Toxic substances constitute the second of three critical
areas studied under the CBP. Most of the research focused on
determining the status of both metals and organic compounds in
Chesapeake Bay. Investigators looked at the concentrations of
these substances primarily in bed sediments, suspended
sediments, and some bivalves, such as oysters. Sources of
metals and organic compounds were also investigated. A limited
amount of research was performed on assessing the toxicity of
metals and organic compounds.
Toxic substances are usually defined as chemicals that can
harm plants and animals, including humans, or impair physical
or chemical processes. The two classes of toxic substances are
inorganic and organic compounds. Inorganic materials are
metals such as arsenic (As), cadmium (Cd), chromium (Cr),
copper (Cu), and zinc (Zn). Many of the organic compounds are
a product of human activities. The main classes are
pesticides, phthalate esters, polynuclear aromatic hydrocarbons
(PNA's), and other chlorinated hydrocarbon compounds (DDT,
Kepone and industrial PCB).
Key findings to date include:
o The highest concentrations of metals in bed sediments
are in Baltimore Harbor and the Elizabeth River,
o In the Bay, the highest metal concentrations in
sediment occur in the northern Bay, particularly on
the western shore. Analysis also showed that at least
half of the metal loads for Cr, Cd, Cu, and lead (Pb)
come from human sources,
o The northern Bay shows high concentrations of metals
in suspended material. The suspended sediments in
near-surface water in the central Bay are enriched in
metals.
o Concentrations of organic compounds are highest in the
northern Bay with a concentration maximum occurring in
the vicinity of Baltimore Harbor and the Susquehanna
River mouth. They tend to increase up the Bay from
the Potomac River mouth toward Baltimore Harbor.
North of Baltimore the concentration, although still
significant, decreases somewhat, but then increases to
another maximum concentration level at the Susquehanna
River mouth.

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o In the southern Bay, the highest concentrations of
organic compounds are found at the river mouths.
These concentrations are higher in the Patapsco and
Elizabeth Rivers than in the main Bay.
o Atmospheric, riverine, and point sources contribute
most of the potentially toxic metals to Chesapeake
Bay. There is also a very substantial contribution of
trace metals from the sediment to water column.
Contributions from three major rivers (Susquehanna,
James, and Potomac at the fall line) account for over
40 percent of the load for Cr, Pb, Cu, Zn, and Fe.
These river loads include municipal, nonpoint, and
industrial sources above the fall lines,
o The Susquehanna River contributes a greater proportion
of total metals than the Potomac or the James, but the
concentration levels are about the same. The
Susquehanna River load is higher because of greater
total flow. The Susquehanna is most significant
because the loads at its mouth directly enter the Bay,
and are not trapped in the sub-estuary like the James
and Po tomac.
o Industrial and municipal inputs below the fall line
are major contributors of metals to the Bay.
p Sources of organic compounds to the Bay are
human-related. In particular, organic compounds in
northern-Bay sediments come from the Susquehanna
River, and possibly from the Patapsco River,
o Toxic chemical concentrations that cause mortality in
aquatic life were found in the Bay.
o The highest mortalities occur in samples from the
upper reach of the Patapsco and Elizabeth Rivers, and
the northern Bay. From these sediment toxicity
studies, EPA feels the Bay north of Baltimore is
, enriched in excess of naturally occurring levels.
SUBMERGED AQUATIC VEGETATION
Submerged aquatic vegetation (SAV) has, in the past, been
very abundant throughout Chesapeake Bay. Current evidence
indicates a pattern of SAV decline that includes, all species in
virtually all sections of the Bay. A marked decline has
occurred throughout the estuary since the mid-19601s. Present
abundance of Bay grasses is at its lowest level in recorded
history.
The Bay grasses are of vital importance to the Bay because
of their value as high primary producers, a food source for
waterfowl, a habitat and nursery area for many forage fish and
juvenile blue crabs, a control for shoreline erosion, and a
mechanism to buffer negative impacts from excess nutrients.
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Key findings to. date include:
o Present abundance of Bay grasses is at its lowest
level in recorded history,
o SAV declines are highly correlated with changing
water-quality conditions, such as decreasing water
clarity resulting from increased nutrient enrichment
or higher loads of suspended sediments from dredging
or land runoff,
o Sediment composition and light availability are the
important factors controlling the.distribution of SAV
within regions of the Bay.
o The decline of SAV parallels historical increases in
nutrients and chlorophyll a concentrations in the
upper Bay and major tributaries,
o Herbicides are generally not available to SAV in toxic
levels, and their presence alone probably did not
cause the SAV decline. However, herbicide-induced
impacts could, in concert with, the other major
stresses (such as from light limitation), create
intolerable conditions for SAV existence.
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RELATED BENEFITS
The EPA funded research on Chesapeake Bay has produced
several benefits which were not anticipated at the time. They
include the establishment of an approach to water quality and
resource management, and an unparalleled data base and
statistical analytical capabilities.
The management approach has been a committee with
representatives from Maryland, Virginia, and Pennsylvania, the
Citizens Program for the Chesapeake Bay (CPCB), and the
scientific/technical community. The Committee has met monthly
since the beginning of the Program and is characterized by an
atmosphere which encourages an open exchange of views and
positions.
A second major benefit is the development of an
unparalleled data base. EPA researchers realized immediately
that the only way to understand a system as complex as the Bay
was to develop a computer-based data management system. The
system designed in 1978 and presently in operation is the
largest refined data base on water quality and resources for a
single estuary known to exist anywhere.
Chesapeake Bay Program scientists first developed an
initial inventory of data bases relevant, to the priority
program areas. Next, scientists from major research
institutions and universities in the Bay area were asked to
identify data and research not on the CBP inventory, and to
recommend an optimum data baseline. After the data were
identified as priority data, they were catalogued by subject
(water quality variable), location on the Bay, and time of year
the observation was made. This information was placed on a
grid to help CBP scientists and managers identify both data
concentrations and data voids.
Datasets that were identified by CBP staff Bay researchers
as having sufficient size to warrant inclusion were obtained
and put on-line on the CBP computer network. After intensive
quality assurance evaluation, the datasets were analyzed to
establish, where possible, trends and past and present
conditions.
The data base creation and more importantly, its use by
scientists and planners alike, is an outstanding achievement
not only for the Bay community, but for scientists, managers,
and interested public anywhere who are concerned about
relationships between estuarine system use, and water quality
and resources.
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TRANSFER OF TECHNICAL FINDINGS
CONTROL STRATEGIES
The CBP effort to determine the condition of the Bay
indicates that the northern Bay, Potomac and James Rivers, and
the upper western tributaries in general are enriched with
nutrients and are sites of current problems; the mid Bay and
eastern shore are less enriched but could become problem areas
in the future. Baltimore Harbor and the Elizabeth River are
enriched in excess of naturally occurring levels with toxic
compounds and the upper Bay has relatively high levels of
organic materials and metals. In. light of these findings, the
Management Study is exploring area alternative control
strategies to reduce pollutant loading to these areas. These
strategies include both point and nonpoint control options.
Nutrient control options include a range of effluent
phosphorus and nitrogen limits on sewage treatment plants, a
phosphorus detergent ban, and agricultural nonpoint source
control practices such as minimum tillage, strip contouring,
etc. Watershed model runs indicate that the effectiveness of a
given control practice varies from area to area. For example,
nutrient point source controls are most effective in the James
and Patuxent Rivers whereas nonpoint controls have the greatest
impact in the Susquehanna River Basin. Therefore, the CBP
management study emphasizes:
o Nonpoint source control strategies to alleviate the
upper Bay problem, and
o point source control strategies to alleviate the
nutrient enrichment problem in the James and Patuxent
Rivers.
Toxic control options include more stringent effluent
control on industry and urban runoff controls. In both
Baltimore Harbor and Elizabeth River, industries are making a
concerted effort to reduce effluent concentrations and
communities are working to reduce urban runoff. Research has
shown that these areas are fairly efficient traps for toxic
compounds. However, modeling efforts also indicate that
certain metals such as cadmium appear to remain in a soluble
form, and migrate out of the harbors. In light of these
findings, the management study emphasizes careful dredge
disposal practices and greater efforts to control specific
problem compounds.
To assess the social, political, and economic feasibility
of alternative management strategies, the CBP relied on advice
from several groups including the Citizens Program for the
Chesapeake Bay and.its Resource Users Team, State Water Quality
Managers Teams, the Bi-State Working Committee, and the
Chesapeake Bay Legislative Commission.
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Last, appropriate management of a system as complex as the
Bay requires careful monitoring. The characterization effort
has defined existing and potential problem areas that should be
carefully watched. Modeling efforts have identified existing
and future sources of pollutant loading and their potential
impact. Given this information, the CBP will propose a
monitoring strategy that will provide an ongoing evaluation of
pollutant sources, transport, fate, and effects.
. FUTURE MANAGEMENT
The findings of the technical studies underscore the fact,
that the Bay is not only composed of unique areas, it is also
an ecosystem that ignores State boundaries. Actions in any
part of the watershed of the Chesapeake Bay may result in water
quality degradation and impacts on aquatic resources downstream
and in the Bay itself. Effective management of Chesapeake Bay
must be based on an understanding of the entire Bay ecosystem.
The findings also imply that both the States and the
Federal government need to exert additional control over point
and nonpoint sources of nutrients and toxic substances. Both
must continue to coordinate their activities to assure that the
control options posed by the Bay characterization effort, and
supported by the model production runs, will be given adequate
public and technical exposure. There is a clear need for some
management system to maintain the interstate perspective and to
ensure that Federal, State, and private strategies are
coordinated., EPA Region III remains committed to assisting in
this task to the extent that funds and personnel restrictions
allow.
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