Centennial, Colorado, faced the need to handle more wastewater while meeting the needs of irrigation.
Mott MacDonald designed an expanded wastewater treatment plant that could handle an increased flow of wastewater while producing effluent suitable for use in irrigation. The plant would have to meet a very stringent total phosphorus permit limit.
Major components of the expanded plant included a new headworks building, new clarifiers 80 feet (24 meters) in diameter, and two new three-stage biological nutrient removal reactions. The reactors were equipped with swing zones to allow several different working configurations.
The completed wastewater reclamation treatment plant saves energy and provides an economical means to extend available water resources. One hundred percent of tertiary effluent is reused during the irrigation season.