Chesapeake Bay Program

A Watershed Partnership

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Over the next several years,
Delaware, Maryland, New York,
Pennsylvania, Virginia, West
Virginia and the District of
Columbia will continue their joint
effort to improve water quality for
the plants and animals living in
the Chesapeake Bay and its
tributaries.

Working with the U.S.
Environmental Protection Agency,
this seven-jurisdiction cooperative
partnership will continue to work
together to improve water quality
through an innovative process that
uses three simple, yet
encompassing, criteria to monitor
the health of the Bay's complex
ecosystem and living resources —
dissolved oxygen, chlorophyll a
and water clarity.

This paper outlines the critical
steps in this new process.

Chesapeake bay
Program

1983-2003

Restoring the Chesapeake Bay:

How We Get There

Water Quality Criteria for the Chesapeake Bay

Prior water quality criteria applied to the Chesapeake Bay were based
on the assumption that all areas in the Bay were identical and did not
take into account the natural variability found in the Bay's waters. Newly
proposed water quality criteria - dissolved oxygen, chlorophyll a and
water clarity - vary based on the needs of a healthy ecosystem. By
analyzing the relationship between these three criteria, scientists are
able to understand and monitor the more complex processes of the Bay
ecosystem. Design and implementation of tributary strategies to meet
these new, more appropriate criteria will enable the states and the
District of Columbia to remove the Bay and its tidal tributaries from the
impaired waters list.

Designated Uses and the Bay

A "designated use" refers to a water body's primary function - such as
fishing or swimming - and takes into account the use of the water body
for public water supply, the protection offish, shellfish and wildlife, as
well as its recreational, agricultural, industrial and navigational
purposes. The suitability of the water body for these uses is also
examined based on the physical, chemical and biological characteristics
of the water body, its geographic setting and scenic qualities, and
economic considerations.

To better position the states and the District to adopt new water quality
standards that relate to the needs of the Bay's living resources, the Bay
Program has developed and recommended five new refined designated
uses for the Chesapeake Bay derived from different types of habitat. The
five habitats - shallow water, open water, deep water, deep channel,
and migratory and spawning areas - allow the water quality standards
to be matched with the plants and animals that are adapted to life in
those different areas, rather than on a single baywide standard.

more

The Chesapeake Bay Program is restoring the Bay through a partnership among the U.S. Environmental Protection Agency representing the federal
government, the State of Maryland, the Commonwealth of Pennsylvania, the Commonwealth of Virginia, the District of Columbia, the Chesapeake
Bay Commission, and participating citizen advisory groups.


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Restoring the Chesapeake Bay: How We Get There

2

Water Quality Standards &

Water Quality Criteria

Standards combine water quality criteria
and designated uses to produce a target
numeric value that, if achieved, will
maintain healthy water quality. Together,
the states and the District must achieve
the standards needed for a thriving
ecosystem if the Chesapeake Bay is to be
removed from the list of impaired waters.

Cap Load Allocations & Implementation

Cap loads are the maximum amounts of
pollutants allowed to flow into a
waterbody and still ensure achievement
of the water quality standards.

Bay Program partners used the
Chesapeake Bay Watershed and Water
Quality Models, along with monitoring
data, to help determine these cap loads
for nitrogen, phosphorus and sediment.
These models are computer
representations that simulate the real
world, interpreting various levels of
actions (management scenarios) to
reduce different amounts of pollutant
loads. These scenarios were run through
the models to determine how to achieve
baywide attainment of the water quality
criteria.

The models, along with other information,
were used to allocate cap loads to the
nine major tributary basins in the
watershed, and, then to twenty
state-specific sub-basins. Each state and
the District bear a proportional burden for
achieving and maintaining the assigned
cap based on their pollutant loadings and
effects on different tributaries.

The Role of Tributary Strategies

Tributary strategies are the blueprint for
improving Bay water quality by outlining
the types and amount of reductions
needed in a particular river basin. Each
tributary strategy will be based on
meeting the assigned cap load
allocations. Strategies will outline the
pollution reductions actions required to
achieve the cap load allocations.

Development of tributary strategies has
traditionally been a very public process
with the direct participation of local
governments and a wide variety of other
interested stakeholders. In creating the
strategies, the states and District of
Columbia will explore and evaluate a wide
variety of point and nonpoint source
control measures. They will then draft a
strategy using the most effective
reduction options to achieve the cap load
allocations.

Permits & Improving Water Quality

The 1972 Clean Water Act prohibits point
source pollutants from being discharged
into a waterbody without a National
Pollutant Discharge Elimination System
(NPDES) permit. The permit limits what
can be discharged, requires monitoring
and reporting, and ensures that the
discharge is not harmful to water quality
or human health.

Together, EPA, the states and the District
are developing an approach for
addressing permits that are consistent
with the overall cooperative process.

For additional information about restoring Chesapeake Bay water quality, visit

http://www.chesapeakebay.net.

4/2003


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