Sewage Treatment

There are three main sewage treatment plants (STP) currently servicing the Wagga Wagga area, these STP are at Narrung Street, Kooringal and Forest Hill. There are also two minor STPs, one at Uranquinty and one at Tarcutta. Effluent reuse is also active in Wagga Wagga.

Each sewage treatment plant has to be licensed under the Environment Protection Authority (EPA). For more information visit the EPA website at www.epa.nsw.gov.au.

Narrung Street Sewage Treatment Plant

Wagga Wagga City Council operated a Sewage Treatment Plant (STP) at Narrung Street, approximately 2 km north of the CBD. It is the largest plant in the government area and its main objective is to treat sewage collected from Wagga Wagga, Sth Wagga, Bourkelands, Ashmont, Turvey Park, Mt Austin, Tolland, Glenfield Park, Cartwrights Hill, Estella and the northern industrial area. Sewage from the industrial area initially undergoes pretreatment at the new Bomen Industrial Sewage Treatment Facility (BISTF).

The treatment load consists of a mixture of domestic and industrial, with each having a separate process stream. The domestic treatment unit includes screening, grit removal, primary sedimentation, trickling filtration, humus tanks and tertiary ponding. The industrial treatment process begins with a sequencing batch reactor (SBR) at BISTF, followed by screening, extended aeration, secondary clarification and tertiary ponding. Sludge at the plant is treated by biological digestion and is stored in two sludge lagoons. The sludge is periodically removed to licensed landfill.

The final effluent from both processes is discharged to either the Murrumbidgee River or into the network of effluent reuse/irrigation projects administered by the Council.

Kooringal Sewage Treatment Plant

Wagga Wagga City Council operates a STP located at Vincent Road, Kooringal, approximately 8 km southeast of the CBD. The main objective of the plant is to treat sewage collected from the areas of Kooringal, Tatton, Lake Albert, and the pressure sewer from East Wagga and Gumly Gumly.

The treatment load primarily consists of domestic sewage with a light industrial area located within the sewer catchment. The first step in the process consists of screening and grot removal. Following these stages, the flow splits into two process streams for further treatment. Approximately 15% is treated through primary sedimentation, trickling filtration and secondary filtration. The remaining 85% passes through a newer treatment process and includes primary sedimentation, high rate trickling filtration, aeration and secondary sedimentation.

All effluent flows into tertiary ponds. Waste sludge is digested and held in two lagoons, where it is removed to landfill when required. The final effluent from the process is discharged into either the Murrumbidgee River via Marshall's Creek or into the network of effluent reuse/irrigation projects administered by Council.

Forest Hill Sewage Treatment Plant

Wagga Wagga City Council operates a STP located at Braehour Road, Forest Hill, approximately 7 km east of the CBD. The main objective of the plant is to treat sewage collected from the residential area of Forest Hill and the local RAAF base.

The plant consists of two separate treatment facilities; one services the residential population of Forest Hill while the other is for the load generated by the RAAF base. The residential plant consists of a Pasveer ditch which received incoming sewage. Clear treated effluent is decanted to tertiary ponds for 30 days storage and ultra violet disinfection, after which it is transferred to a storage lagoon for irrigation onto a treelot.

The RAAF plant consists of aerated lagoons where treated effluent is transferred to storage ponds for use on surrounding agricultural land. This effluent is always mixed with river water prior to application.

Effluent Reuse

Treated effluent from Narrung Street and Kooringal STPs is used for irrigation purposes on a number of sites around Wagga Wagga. The use of this effluent is closely monitored. Narrung Street STP effluent is used on a number of sites, including; on-site, Bolton Park, Wagga Wagga Cricket Ground and Mc Pherson Oval. Kooringal STP reuse sites include Rawlings Park and an onsite treelot.