The Texas Commission on Environmental Quality (TCEQ) has completed the draft 2022 Guidance for Assessing and Reporting Surface Water Quality in Texas as well as the response to comments from the 2022 Integrated Report Surface Water Quality Assessment Advisory Work Group meeting held last November meeting.
The draft 2022 Guidance includes revised assessment outcomes in Appendix F for nutrients in reservoirs with approved chlorophyll a criteria. TCEQ has been in recent discussions with EPA Region 6 regarding TCEQ’s existing assessment outcomes in Appendix F. Based these discussions, TCEQ revised the Appendix F assessment outcomes and the following is a summary of those changes:
Reservoirs exceeding their chlorophyll a criterion in Appendix F of the Texas Surface Water Quality Standards would be impaired and identified as not supporting. Those with additional information indicating a causal or response relationship would be included on the Texas 303(d) List in a new sub-category 5n, per the pathways described in the revised line of evidence flow chart in Appendix F of the draft 2022 Guidance. Reservoirs in sub-category 5n will be prioritized for additional studies and management efforts. Additional details about Category 5n are included in the draft 2022 Guidance.
The other reservoirs that exceed their chlorophyll a criterion, but information indicates there is not a causal or response relationship, would be included on the Texas 303(d) List in sub-category 5c. The existing assessment outcome for reservoirs without approved numeric nutrient criteria remains unchanged.