Backflow, Explained
The water supply system is designed to ensure that water flows to your property under pressure. There is a risk to public health if there is a cross connection between your water supply and a contaminated source. If there is a pressure drop in the water main, a vacuum could be created in the water supply system. Under certain conditions this creates a siphoning effect and draws liquid from a contaminated source back into the drinking water supply.
Water pressure can be affected when:
- there is a break in the water main
- water is being pumped from the main water supply during a fire
- a customer is using water at a higher pressure than the pressure supplied.
- heavy water use downstream reduces water pressure upstream
- the water outlet at the property is higher than the water main, causing constant back pressure.
A number of different property types pose a particular risk through cross connections.
These include:
- chemical plants
- pest controllers
- market gardens
- golf courses/sporting ovals
- caravan parks
- greywater treatment systems
- metal processing plants
- paint manufacturers
- laundries
- nurseries
- residential properties with rainwater storage.
If your site needs surveying for cross connection call us for a consultation.