Tema Engineers team were invited by South Australia (SA) Water to review the water purification requirements of a major reservoir on Kangaroo Island. The island is located 15 km off the SA coast, with a population of around 400 permanent residents in 2008. It is roughly seven times the size of Singapore and is also home to a multitude of native wildlife species.
The Challenge – Creating More Clean Water
Kangaroo Island’s Middle River Reservoir supplies 470 mega litres of potable water to the townships of Pardana and Kingscote. Our team were asked to implement a solution that would address the capacity and effectiveness of water purification for the reservoir, with the aim of supplying 3 million litres of clean water every day.
Water from Middle River was found to have high levels of iron and sediment. Although these levels did not pose a health risk, occasional discolouration of the water led to customer complaints. Population growth on the island, due to economic growth and tourism, also led to the need for a reliable and plentiful supply of good quality potable water.
Tema’s solution – The Middle River Filtration Plant
Having investigated the reservoir environment, our engineers installed a customised, end to end water filtration plant. The water filtration plant was operational within 12 months of project approval.
Coagulation And Flocculation – This vital stage in the water filtration process prepares water for sedimentation. A coagulant binds together impurities to create denser particles that settle out during the sedimentation process. The Tema engineers installed two flash mixers and flocculation tanks, used to deliver Caustic Acid for pH control and Alum as a coagulant.
Sedimentation – Tema’s Lamella water separator models LSF90/55/50 offer space saving advantages as well as industry leading results in sedimentation. They can occupy up to 90% less space than standard settling tanks. 2 Lamella separators were manufactured and installed for the Middle River plant.
Filtration – the three Tema CWUF sand filters installed provide an excellent solution in terms of capacity and purity during the water filtration stage. They can handle rapid flow rates and remove a high level of suspended solids from water. The filters are cleaned by an internal washing system, removing the need for backwashing tanks.
The result: a compact solution for an abundant supply of clear, clean water.
Disinfection – chlorine is added prior to storage, to ensure that all micro-organisms in the water are removed. TEMA supplied and installed all equipment for the chlorine delivery mechanism.
Following installation of the Middle River plant, the quality of the water supply increased dramatically, safeguarding future growth for Kangaroo Island’s population, tourism and industries.
- Water test results demonstrated the following improvements:
- Water turbidity reduced from 8.9 NTU to 0.31 NTU.
- Water colour reduced from 90 HU to < 1HU.
- Aluminium content reduced from 0.644 to o.164 mg/L
- Iron content reduced from 0.841 to 0.014 mg/L
- Manganese content reduced from 0.032 to 0.016 mg/L