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Ambient Water Quality Criteria
For Dissolved Oxygen, Water Clarity and Chlorophyll a for
Chesapeake Bay and its Tidal Tributaries
The Chesapeake 2000
agreement 
committed its signatories (the states of Pennsylvania, Maryland and Virginia;
the District of Columbia; the Chesapeake Bay Commission and the EPA) to,
"by 2001, define the water quality conditions necessary to protect aquatic
living resources." New York, Delaware and West Virginia agreed to the
same commitment through a separate six-state
memorandum of understanding [PDF, 2 pages, 94K, about pdf] with the EPA. Accordingly, the EPA has defined the water quality
conditions through the Chesapeake Bay-specific water quality criteria
for dissolved oxygen,
water clarity
and chlorophyll
a
published in the Ambient Water Quality Criteria for Dissolved Oxygen Water
Clarity and Chlorophyll a for the Chesapeake Bay and Its Tributaries (Regional
Criteria Guidance) below. The EPA has identified and described five habitats
(or designated
uses)
that provide the context in which EPA Region III derived adequately protective
Chesapeake Bay water quality criteria for dissolved oxygen, water clarity
and chlorophyll a. Collectively, the three water quality conditions provide
the best and most direct measures of the effects of too much nutrient
and sediment pollution on the Bay's aquatic living resourcesfish, crabs,
oysters, their prey species and underwater bay grasses. These criteria
are being developed as part of a larger effort to restore
Chesapeake Bay water quality.
EPA has also conducted a Biological Evaluation [PDF, 61 pages, 1.6M, about pdf] to assess the potential effects of the Regional Criteria Guidance on federally listed species found in the Chesapeake Bay and its tidal tributaries. The Biological Evaluation provides findings and conclusions that will be evaluated by the NOAA National Marine Fisheries Service under the authority of Section 7 of the Endangered Species Act.
The Technical Support Document for the Identification of Chesapeake Bay Designated Uses and Attainability, describing the development and geographical extent of the designated use to which the criteria may apply, will be published in June 2003.
The following are PDF Files [ about pdf].
Download the entire document
[343 pages, 4.2M] or separate
sections below.
Executive Summary
Cover Page [1 page, 65K]
Title Page [1 page, 19K]
Foreword [1 page, 78K]
Executive summary [10 pages, 211K]
Notices [1 page, 30K]
Acknowledgments [3 pages, 71K]
Table of Contents [4 pages, 42K]
Text
Chapter I: Introduction [4 pages, 81K]
Chapter II: Chesapeake Bay Nutrient and Sediment Enrichment Criteria [2 pages, 27K]
Chapter III: Dissolved Oxygen Criteria [73 pages, 469K]
Chapter IV: Water Clarity Criteria [19 pages, 174K]
Chapter V: Chlorophyll a Criteria [44 pages, 504K]
Chapter VI: Recommended Implementation Procedures [58 pages, 879K]
Chapter VII: Diagnostic Procedures for Natural Processes and Criteria Nonattaiment [19 pages, 335K]
Glossary [7 pages, 45K]
Acronyms [1 page, 19K]