Ill 
Contents 
Acknowledgments . v 
I. Introduction . 1 
Literature Cited. 3 
II. Refinements to the Chesapeake Bay Water Quality Criteria 
Assessment Methodology . 4 
Background. 4 
Overview of the CFD Assessment Methodology. 5 
Description and Evaluation of the CFD-Based Assessment Methodology . . 9 
Example CFD-based criteria assessment . 9 
CFD reference curves . 12 
Comparing assessment and reference curves . 15 
Development of a statistical decision-making framework . 16 
Results of the scientific evaluation . 19 
Application of the CFD-Based Assessment Methodology. 21 
Recommendations for application of the CFD-based methodology . 21 
Recommendations for future refinement of the 
CFD-based assessment methodology . 23 
Literature Cited. 24 
III. Application of Chesapeake Bay Water Quality Criteria 
Assessment Procedures . 25 
Background. 25 
Assessment Units, Segmentation, and Sub-Segmentation. 26 
Data to be Used in Chesapeake Bay Criteria Assessments . 28 
Updating the Criteria Attainment Assessment Framework . 31 
Literature Cited. 32 
IV. Refinements to the Chesapeake Bay Dissolved Oxygen Criteria 
Assessment Procedures . 33 
Background. 33 
Temporal Periods for Assessment of Dissolved Oxygen Criteria. 36 
Dissolved Oxygen Criteria Assessments in Shallow Waters 
Versus Open Waters. 37 
Assessment of Short Duration Dissolved Oxygen Criteria . 38 
Dissolved Oxygen Criteria Reference Curves . 39 
Contents 
