Case study 3

Wastewater system improvements

During heavy rain or extended rain periods, parts of the wastewater system can become overloaded by:
• Stormwater seeping into cracked pipes
• Illegal connections of stormwater into the sewerage system
• Damaged customer fittings
• Poorly located customer fittings such as low-lying sewer shafts or yard sinks.
Sewage overflows can have detrimental impacts upon the environment. To maintain performance during wet weather Hunter Water is upgrading its sewerage system. The work will reduce the amount of water entering the sewerage system in wet weather, increase the capacity of the system and thus reduce the likelihood of sewage overflows.

 

Upgrade of Lake Macquarie Wastewater Transportation System

Upgrades to the Warners Bay/Valentine Wastewater Transportation system were completed in 2006. This project included the upgrade of six pump stations as well as the upgrade of 6.5 km of rising main and 12 km of gravity carrier mains.
The capacity of the system to transport wastewater has been almost doubled as a result of the works and customers will notice a significant improvement in the quality of service provided by Hunter Water’s wastewater system, particularly in wet weather.

 

Newcastle Wastewater Transportation System

New pumping stations will be built at Mayfield and Lambton, and larger pipes installed to transfer flows directly to the Burwood Beach Wastewater Treatment Works.
The section of pipeline below the Merewether hills has been constructed using a technique known as ‘directional drilling’. This involves a pipeline being drilled deep beneath the surface. This technique avoids the installation of pumping stations and hence reduces energy requirements of the system. The cost of this total upgrade work is approximately $34 million.

 

Priority Sewerage Program

As part of the NSW State Government’s Priority Sewerage Program, Hunter Water is providing sewerage services to small townships which have been identified as a priority. Areas under consideration for requiring sewerage services were prioritised by the Department of Environment and Climate Change based on potential health and environmental risks.
In the Hunter, the townships of Kitchener, Lochinvar, Millfield, Ellalong and Fern Bay were identified as priority areas. Services at Fern Bay and Kitchener have now been completed, construction at Lochinvar is well progressed planning work for Millfield and Ellalong is well advanced.