Private water supplies are those sources of water not provided by a public water supply authority. In many rural areas they are the only source of water and are usually derived from rainwater harvesting, creeks, or bores. Even in relatively pristine areas, it is possible for such water supplies to become contaminated.
Sources of Contamination
Your private water supply can be contaminated by things such as:
Giardia and Cryptosporidium are commonly transmitted via animal and human faeces. These organisms in contaminated water supplies have been responsible for major outbreaks of severe gastric illnesses such as gastroenteritis and infections. These illnesses are particularly dangerous to the very young, the elderly, and people with poor immune systems.
Cryptosporidium are particularly resistant to chlorination and are difficult to detect and remove from water supplies.
This is of even greater concern during doughts as the dry periods allow a greater build up of dust and droppings in roofs and gutters. When the rain arrives, the falls are often sudden and heavy, washing this debris into tanks and resulting in above average contamination of water, particularly in tanks without a first flush diversion device.
First Flush Devices
In fact, even where first flush devices are fitted there has been some question as to whether they work as well as they should - see, for example, Rainwater First Flush Devices – Are They Effective? 1 In this report the authors concluded that
1 Rainwater First Flush Devices – Are They Effective? Gardner T, Baisden J and Millar G (2004) 'Sustainable Water in the Urban Environment, 2004 Conference', Brisbane, Australia. August 30-31, 2004.
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