The Lower Neches Valley Authority (LNVA) needed assistance in designing and building a new state-of-the-art 5 MGD regional water treatment plant. This plant replaced an aging groundwater system and supplied high quality potable water to the communities along the Bolivar Peninsula in Galveston County. In addition to the water treatment plant, the project also entailed 33 miles of transmission line, storage facilities and pumping stations.
Raw water is provided by a lateral of the Neches River main canal. Upon entering the plant, the water is sent into an aeration basin prior to clarification. Sodium hydroxide, a coagulant and a polymer are added to aid in flocculation and settling. The RotaClear™ clarifiers are custom fabricated from stainless steel to eliminate long-term maintenance costs. The RotaClear™ clarifiers use a single drive rotor mechanism that provides for primary and secondary mixing zones as well as solids recirculation. A polymer is added between the mixing and settling zones of the clarifiers to promote coagulation. Clarifier effluent then passes through a chlorine contact basin and into the filters.
The four Filtralator™ gravity filters are designed with additional expansion space should granular activated carbon (GAC) be required in the future. The clarified water is flow-controlled by valves and split equally into the dual media filters. The Tonka Water Unicast™ underdrains are a monolithically poured 6” thick false floor, media-retaining nozzles. Each filter cell includes the value-added Simul-Wash™ backwash process.
The raw water analysis summarized reflects moderate concentrations of iron and manganese existing in the water. The treatment process has been highly efficient in delivering high quality water as indicated.
|Turbidity||40-50 NTU||<1 NTU||0.05 NTU|