Final Water Quality Assessment Guidance Manual

The 2012 305(b)/303(d) assessment methodology guidance remains largely unchanged, with the exception of changes that reflect new Water Quality Standards that became effective in Virginia on January 6, 2011. These changes principally include:

• Revised methodologies for the determination of pycnocline boundaries and the reference curve used in the assessment of dissolved oxygen in the Chesapeake Bay and its tributary rivers.
• A geometric mean has been explicitly specified for use in the assessment of seasonal chlorophyll a criteria in the tidal James River.

Furthermore, the 2012 guidance includes a more detailed methodology for assessing continuous monitoring datasets.

A copy of the guidance can be downloaded at this link: Final 2012 WQA Guidance Manual (3.87 MB PDF)

There are two documents referenced under Section 6.5.2 in the PDF of the Final 2012 WQA Guidance Manual. Links to those documents are included here:

Weight-of-Evidence Workbook – Blank Template (172 kb Excel workbook)
Weight-of-Evidence Workbook – Completed Example (2.17 MB Excel workbook)

A copy of the comment response can be downloaded at this link: 2012 Comment Response (1.42 MB PDF)

For a hard copy of the guidance or for more information, please contact Tish Robertson, PhD, DEQ Water Quality Assessment Coordinator, using the information below.

Contact:

    Tish Robertson
    Virginia Department of Environmental Quality
    Water Quality Assessment Coordinator
    P.O. Box 1105
    Richmond, Virginia 23218
    Telephone (804) 698-4309
    FAX (804) 698-4032

Click here for a copy of the Public Notice (16 kb PDF)