South Mesquite Creek Regional Wastewater Treatment Plant in Dallas, TX

Client: North Texas Municipal Water District
Construction: Archer Western Contractors
Project Engineer: Black & Veatch

The Problem

  • Surface Vortices: Excessive vortex activity in the wet well created uneven flow conditions, impacting pump efficiency.
  • Turbulence and Air Entrainment: Turbulence in the system led to air entering the pumps, which reduced performance and increased wear.
  • Capacity Needs: To accommodate projected growth and wet weather events, the facility’s capacity needed to expand to handle up to 102.5 MGD.

Solution

To mitigate these challenges and prepare for future demands, the Flow Optimizer Basket/Spool assembly was installed to address the flow dynamics in the wet well. This system was designed to:

  1. Lower the Point of Suction: Ensured that the suction point was positioned to minimize air entrainment.
  2. Straighten Flow: Improved alignment of flows entering the pumps, reducing turbulence and enhancing efficiency.
  3. Support Capacity Expansion: Optimized flow conditions to handle increased daily and peak flow demands.

The South Mesquite Creek Regional Wastewater Treatment Plant (RWWTP) in Dallas, TX, faced significant operational challenges as its influent flows regularly exceeded the rated wet weather capacity of 82.5 MGD. Surface vortices, turbulence, and air entrainment disrupted pump performance, risking operational inefficiencies and potential system failures. With growth projections indicating the need to expand average daily capacity from 33 MGD to 41 MGD by 2026, the facility required immediate and future-proof solutions to address these challenges.

 

Phased Project Approach

The project was divided into three strategic phases to ensure seamless integration and capacity improvements:

1. Early Peak Flow Relief

  • Repurposing an abandoned secondary clarifier as Peak Flow Storage Basin No. 3.

2. Peak Flow Improvements

  • Development of Headworks No. 2 and Peak Flow Storage Basin No. 1.
  • Installation of parallel 42-inch force mains to manage peak inflows.
  • Upgrades to electrical buildings and gear to support peak flow operations and future expansions.

3. Expansion to 41 MGD

  • Enhancements to primary, secondary, and tertiary treatment processes to increase average daily capacity and meet future demands.

Results

  • Improved Flow Stability: The Flow Optimizer Basket/Spool assembly significantly reduced turbulence and vortex activity, stabilizing flow dynamics.
  • Increased Pump Efficiency: Air entrainment was minimized, allowing pumps to operate more effectively and with less maintenance.
  • Future-Ready Infrastructure: The facility is on track to meet its expanded daily capacity of 41 MGD by 2026 and handle peak wet weather flows of up to 102.5 MGD.
  • Cost-Effective Operations: Enhanced flow conditions reduced wear on pumps, lowering long-term operational costs.

Project Drawings

Conclusion

The South Mesquite Creek RWWTP’s proactive adoption of advanced flow conditioning technology, paired with strategic infrastructure upgrades, has ensured the facility’s ability to meet current and future demands. The collaboration between North Texas Municipal Water District, Archer Western Contractors, and Black & Veatch highlights a model approach for addressing flow challenges in large-scale wastewater treatment plants.