South Mesquite Creek RWWTP Electrical Improvements

Built in 1958, the South Mesquite Creek Regional Wastewater Treatment Plant (WWTP) was showing signs of deterioration and redundancy vulnerability. In order to increase electrical reliability and redundancy for uninterrupted plant operations and future expansions, Mbroh provided engineering services for four major areas: generators and MV paralleling switchgear design, 5 kV overhead power distribution system design, power company coordination, and ArcFlash hazard analysis/power studies.

Mbroh’s generator design included two standby emergency generator sets, each rated for 2500 kW, 4160V, 3ph, and operational with a paralleling switchgear. In addition, the team changed the existing underground 5 kV distribution system to a 5 kV overhead distribution system (insulator at 25 kV). Although the overhead distribution system is exposed to weather conditions, the design of new concrete power poles increased reliability. These improvements also provided NTMWD with a second power feeder option directly from Oncor, if needed in the future. Mbroh’s completion of ArcFlash power studies further determined potential weak spots throughout the electrical system to improve future operations.