Tumbarumba Sewerage Augmentation - Design Development and Construction of a 2500EP Wastewater Treatment Plant. Replacement of existing Trickling Filter Plant with a 2500EP Intermittently Decanting Extended Aeration (IDEA) Plant. The overall concept philosophy for treatment within the plant augmentation is based on fully treating incoming daily flows up to 3.35 x ADWF, with plant flows between 3.35 X ADWF and 7 X ADWF receiving partial treatment.

Flows above 7 X ADWF will be temporarily detained within a storm pond before pumped return for traetment. Part of the new treatment facility will be constructed over the site of some of the existing tertiary effluent ponds. Those existing effluent ponds that are not affected by siting of the new facilities will be utilised for disinfection treatment of flows from trickling filter plant during construction of the new treatment plant and later decommissioned once the new plant is fully commissioned as the new plant incorporates an ultraviolet (UV) system for disinfection of treated effluent.