Council currently operates five separate sewerage schemes to serve the urban areas of Port Macquarie, Lake Cathie/Bonny Hills, Camden Haven, Wauchope and Kew/Kendall (including Herons Creek).
Each sewerage scheme has been individually designed using the best technology available at the time of construction, and each process is slightly different and unique. The general sewerage treatment process can be divided into four main areas:
- Main Treatment (includes Primary, Secondary and Tertiary) and
- Sludge Treatment.
Extensive underground reticulation networks collect raw sewage from you, the owners of the sewerage system. In total, reticulation networks in the Hastings comprise in excess of 655 kilometers of pipelines and 13,087 manholes, serving approximately 28,000 connected premises throughout the Local Government Area.
Pipes are laid on a slope to allow sewage to flow to the nearest pumping station. There are currently 167 sewage pumping stations within the network. The reticulation network is quite capable of handling normal sewage however, there are certain substances that can cause blockages and subsequently overflows, which can be a major health hazard. Dramatic increases in flows due to storm-water ingress and illegal discharge of trade waste into the system cause operational problems requiring careful management.
Raw sewage contains varying quantities of floating and suspended solids, some of considerable size. Materials such as rags, pieces of wood, metal, plastic, or rubble enter sewers and eventually reach the treatment plant. These need to be removed as their presence interferes with the main treatment process and mechanical equipment involved. In order to remove these problem solids, pre-treatment is used.
Sewage is passed through the various stages of treatment before being either reused or discharged. The overall intention is to separate the pollutants from the water so that both the treated water and the solid by-products can be reused.
All Main Treatment in the Hastings uses the process of Activated Sludge. The Activated Sludge process is widely used in Australia and involves the acceleration of natural microbial growth by aerating. The term ‘Activated Sludge’ refers to the presence of large amounts of bacteria and other microbes in sewage that are feeding off our organic waste. The end result is a very efficient conversion of waste pollutants into their biomass. Various 'polishing' technologies are also used in each STP in the Hastings to ensure the waste-water is clean enough for its final use.
Sludge is created from all processes involved in sewerage treatment. Sludge has a different composition depending on where it comes from. For example, sludge removed from an Activated Sludge Lagoon is different from sludge removed from a Primary Sedimentation Tank.
Most sludge in the Hastings is generated from the Activated Sludge process. Sludge Digestion at the sewerage treatment plants, which converts the solids into a much more stable and odourless form, gives rise to the production of bio-solids. Once thought of as purely a waste product, de-watered bio-solids are now transported to the Cairncross Composting Facility and form a very important ingredient in the composting process.
Bio-solids produced at the Port Macquarie Sewerage Treatment Plant (STP) are not digested, however, due to the process and the continuous de-watering facility at the site, dewatered bio-solids are also used in the composting process.
Currently septic waste from outlying areas in the Hastings is transported by tankers to Wauchope Sewerage Treatment Plan (STP) for treatment. It is anticipated that by mid-2014 septic waste will be transported to Port Macquarie STP. At this time, no commercial septic waste or effluent will be accepted at Wauchope.
This page was last updated on: 01 May 2017