Clean, safe and secure water. A vital part of Cowra Council’s operating responsibilities for their surrounding community.

Cowra’s water treatment plant produces high quality water, however the configuration of the post-treatment reservoirs hampered the Council’s ability to manage their water resources efficiently and cost-effectively. Water often remained in the reservoirs long enough for available chlorine to be oxidised and the Council was unable to guarantee the required chlorine residual at the extremities of their reticulation system. As a result, this caused difficulty in achieving water quality standards and impacted Cowra Council’s drinking water management strategy.

A ResMix Vital system was installed in the 9ML North Cowra No. 7 reservoir to ensure stable chlorine residuals. The machine floats on the surface of the water and uses a proprietary impeller system to move water downwards using less than 0.5kW/hr.

By constantly circulating water, the ResMix Vital creates a homogenous reservoir while reducing the amount of disinfection needed to maintain uniform outputs. Cowra Council has subsequently achieved an improvement in chlorine residual of between 10 and 45 percent, maintaining its requirements under the Drinking Water Standards.

With the improved quality of water and appropriate chlorine residuals, Cowra Council are now able to utilise their No. 7 reservoir as part of their water treatment solution, not just as a water storage facility – securing the supply of consistent and safe water for years to come from this reservoir.

Project Engineer, David Swan, presented this Case Study of the Cowra ResMix installation as a conference paper at the 2015 Water Industry Operators of Australia Conference.