STAC Criteria Addendum Review

The full title of this report is: "STAC Criteria Addendum Review: Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries: 2017 Technical Addendum."

The report outlines the results of the Chesapeake Bay Program (CBP)-requested and STAC-sponsored independent review of the 2017 Technical Addendum to the document: “Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll-a for the Chesapeake Bay and Its Tidal Tributaries.”

The 2017 Technical Addendum was developed by the Criteria Assessment Protocol Workgroup of the Scientific, Technical, Assessment and Reporting (STAR) team, and provides refinements and clarifications to the previously published Chesapeake Bay water quality criteria assessment procedures.

The STAC review panel was tasked with evaluating the latest addendum document by examining previously undocumented features of the present procedures (as well as several refinements and clarifications), through five charge questions for each chapter in the document. Specifically, the panel addressed questions regarding 1) the overall appropriateness and justification of the approach taken, 2) the clarity of the document in providing a complete set of guidance for assessing water quality standards attainment, 3) the scientific rigor of the methods used, and 4) provided recommendations to the CBP about potential future enhanced criteria-assessment procedures.

As a general comment, the review panel noted that a clearly written and complete documentation of the water quality criteria is extremely critical, given that billions of dollars are being spent on the basis of their development. The major findings and recommendations are summarized below, with details specific to each chapter provided within the report.