FAQs

Profile courtesy of Water Infrastructure Group.

What is Ultrafiltration?

Ultrafiltration relates to the size of the membrane pore size that is used in the treatment of water. Membrane filtration starts at microfiltration (the largest filtration by particle size only), then progresses to ultrafiltration (filters only molecules of specified size and weight), nanofiltration (partial desalination) and finally reverse osmosis (almost complete desalination).

The Eastern Irrigation Scheme Ultrafiltration Plant has 640 ultrafiltration membrane modules, each containing around 12,000 capillaries. Each capillary has thousands of 35 nanometer pores that act as a physical barrier to particles and pathogens. E.coli, for example, are typically 500-2000 nanometers in size, while Cryptosproridium are typically greater than 3000 nanometer in size. The width of a human hair is about 50,000 nanometers.

What is the quality of the recycled water and how can it be used?

The recycled water supplied by TopAq is designated by the EPA as Class A recycled water. It has been recycled from wastewater that has previously undergone purification at Melbourne Water’s Eastern Treatment Plant. Further treatment is then provided by the latest ultrafiltration technology to remove harmful pathogens (bacteria, viruses and parasites).

These processes make the Class A recycled water safe for a variety of uses, including horticulture, residential, industrial and recreational applications.

Class A recycled water can be used for direct watering of leafy vegetables that are eaten raw, such as lettuce, celery, spring onions and carrots. It can also be used in residential developments for toilet flushing and garden watering, and for irrigating golf courses, parklands and sporting fields. The use of Class A recycled water is prescribed in the EPA Guidelines for Environmental Management: Use of Reclaimed Water, 2003, and endorsed by the Department of Human Service for unrestricted use, provided it is used in accordance with the guidelines. The Environmental Improvement Plan further sets out these uses in a way that promotes sustainable use and development, and sound environmental management.

How is the environment being looked after?

The EPA has approved a Regional Environmental Improvement Plan (REIP) for the Eastern Irrigation Scheme. The REIP prescribes the framework for managing long-term environmental improvement and sustainability. Nesting under the REIP are a number of site specific Environmental Improvement Plans (EIP) which will define how Class A recycled water is used at each site. Because the conditions and uses at each site vary, it will be necessary to conduct site specific inspections and testing of the soils, drainage characteristics and groundwater quality to ensure that specific site applications of Class A recycled water are managed in a way that fulfils the long-term sustainability established under the REIP. TopAq and Environmental Auditors accredited by the EPA undertake continual monitoring of the scheme. The results of the monitoring must be reported to the EPA against the REIP and EIP objectives for sustainable environmental management each year to ensure compliance and protection of the environment.

Incorporated Association No. A0053003P