Tank water safeguards

When installing a rainwater tank attaching several simple devices may assist in keeping the tank water quality in reasonable condition.

Gutter guards prevent leaf litter entering the tank

If leaf litter enters the gutter, this debris may accumulate and block the rainhead or inlet screen causing uncontrolled overflow and reduce the amount of rainwater collected.

Rainhead diverts leaves

Installing a screened downpipe rainhead on each down pipe just below the gutter sheds leaves, preventing them from entering the tank. Self cleaning types are recommended.

First flush diverter redirects the first polluted flow

Pollutants and debris washing off the roof in the first runoff (20 litres/100 sq.m.) are redirected to the overflow drainage system, protecting the tank from excessive collection of sludge and subsequent organic and chemical contamination.  First flush devices need to be cleaned regularly to function well.

Mosquito and insect screens are required to be fitted on all rainwater tanks

The screen gauze must have a diameter no larger than 1mm aperture mesh

Filters provide additional protection

Various types of filters are available that protect against micro-organisms, chemicals, fine sediments, colour and odour. to perform well they need to be replaced regularly.

Backflow prevention device prevents untreated water contaminating the town water supply 

If there is an interconnection between the rainwater supply and the town water service supplying the outlet valve at fixtures and appliances, such as toilets and washing machines, an appropriate backflow prevention device must be installed to protect against the untreated water in the tank accidentally contaminating the town water supply.

Roofing materials may influence water quality

Rainwater should not be collected from a roof with lead flashings or older painted surfaces which may contain lead.

Positioning of the tank outlet

The outlet should always be above the base of the tank to avoid drawing off sediment that has settled at the bottom of the tank over time.  the tap or outlet should be marked "rainwater" in accordance with Australian standards.