Ill 
Contents 
Acknowledgments . v 
I. Introduction . 1 
Literature Cited. 2 
II. 2008 92-Segment Scheme for the Chesapeake Bay 
Water Quality Criteria . 5 
Background. 5 
Chesapeake Bay Program Segmentation Schemes. 5 
2008 Chesapeake Bay and Tidal Tributaries 92-Segment Scheme. 6 
Unresolved Boundary for District of Columbia Upper Potomac River . . 12 
Literature Cited. 12 
III. Refinements to Procedures for Assessing Chesapeake Bay 
Dissolved Oxygen Criteria . 13 
Background. 13 
Dissolved Oxygen Criteria Assessment: Stations and Accepted Data ... 14 
Pycnocline Definition and Boundaries . 15 
Revising Designated Use Boundaries with Enhanced Pycnocline 
Definition Procedure . 15 
Calculation of Upper and Lower Pycnoclines for Dissolved 
Oxygen Designated Use Criteria Assessment. 15 
Literature Cited. 18 
IV. Refinements to Procedures for Assessing Chesapeake Bay 
Water Clarity and SAV Criteria . 19 
Background. 19 
Revision of the Water Clarity Acres Assessment Methodology . 20 
Clarification of Water Clarity Assessment Procedures. 21 
Statistical Model Revision. 21 
Converting Turbidity to K d for Calculation of Water Clarity Acres . . 21 
Interpolation Software and Approach . 24 
Literature Cited. 24 
Contents 
