East Texas Electric Cooperative Submits Water Quality Notifications for RC Thomas Hydroelectric Project

The East Texas Electric Cooperative, Inc. has submitted notifications to the Federal Energy Regulatory Commission regarding water quality at the RC Thomas Hydroelectric Project (P-12632) for the period of July 2 to July 29, 2025. The notifications were originally transmitted via email to FERC staff and resource agencies but are now being filed in FERC's eLibrary to ensure compliance. The notifications were triggered by elevated summer temperatures in Lake Livingston, a regional condition beyond the project's control, which caused temperature and dissolved oxygen (DO) exceedances.

Key Takeaways:

• The East Texas Electric Cooperative, Inc. submitted notifications to the Federal Energy Regulatory Commission regarding water quality at the RC Thomas Hydroelectric Project (P-12632) for the period of July 2 to July 29, 2025.
• The notifications were triggered by elevated summer temperatures in Lake Livingston, a regional condition beyond the project's control, which caused temperature and dissolved oxygen (DO) exceedances.
• The notifications included data from temperature and DO monitoring stations, as well as spot checks conducted by EthosEnergy and TRA staff.
• Phase 1 of the Post-Startup Monitoring Plan (PSMP) remains the governing monitoring and reporting framework, while Phase 2 implementation is pending review by the Texas Parks and Wildlife Department, the Texas Commission on Environmental Quality, and other consulting resource agencies.
• Going forward, all qualifying notifications will be filed in FERC's eLibrary in addition to being distributed via email.

Statistics:

• Temperature readings ranged from 29-31.0°C (84.2-87.8°F) during the notification period.
• Dissolved oxygen (DO) readings ranged from 2.47-8 mg/L during the notification period.
• Total river flow during the event was approximately 11,500 CFS, with about 4,500 CFS passing through the powerhouse.
• The primary stilling basin water quality probe recorded a DO reading of 2.47 mg/L, which was later confirmed to be a localized low reading.

Sources:

• East Texas Electric Cooperative, Inc. to Federal Energy Regulatory Commission, "Subject: 14-Day Water Quality Notifications Period of July 2 to July 29, 2025 RC Thomas Hydroelectric Project (P-12632)" (FERC eLibrary).
• Ethics of Hydroelectric Power Plant Services Operations and Maintenance Manager James Deric Lee to Ms. Debbie-Anne A. Reese Secretary, Office of the Secretary Federal Energy Regulatory Commission (FERC).