If you can't access mains (reticulated) water, collecting rainwater from your roof is a good alternative. Rainwater is generally safe to drink if it is clear, has little taste or smell and is from a well-maintained system.
Advice on using tank water for drinking or cooking
- Install water filters at your kitchen tap. Water filters remove a range of contaminants from the water, but you will need to choose the best type for you.
- Maintain and replace your filters, following the manufacturer's instructions. Neglected filters may release germs and chemicals into the water.
- Check and maintain the tank and water catchment area twice a year.
- The risk of illness is low for most people. If you don't want to take any chances, you can boil tank water used for drinking, cooking and washing food.
- The risk is higher for people with lower immune response, such as very young children, older people, and people with a chronic illness. These people should always boil tank water used for drinking, cooking and washing food.
What you can do to prevent contamination of your rainwater tank
Before installing a rainwater tank, check with suppliers if your roofing material is safe to be used for collecting drinking water. Make sure your rainwater tank is correctly installed, with screens on all tank inlets and a first flush bypass device.
- Gutters – soil and decaying vegetation can accumulate leading to poor odour/taste of your water. If there is lots of leaf litter, it may need to be done more regularly. Cut back any overhanging branches as this will minimise leaf litter and reduce wildlife climbing on to your roof. You might like to look at bird and animal repelling devices. Guttering can be covered with a screen to prevent leaves entering or accumulating in gutters.
- Roof – check for accumulated debris and leaf litter and remove. Make sure your first flush device works, as this will stop a lot of accumulated roof contaminants from going into your tank when it rains. Keep the roof in good repair. Keep wood heaters in good repair and remove 'Chinese hat' type chimney flue cowls.
- Tank and tank roof – the structure should be sound without any holes or gaps that can let animals or birds in. If you do find gaps, check for dead animals and look for mosquito larvae then close the access points. Also check for any green algal growth. Inspect the tank for sediment or sludge every two to three years.
- Tank inlets, insect proofing and leaf filters – if necessary, these should be cleaned and repaired to stop contaminants getting in.
How your tank water can get contaminated
Water collected from your roof may get contaminated by:
- chemicals from paint or wood fire smoke from the chimney
- micro-organisms from bird and animal droppings
- decaying leaves that have collected in the gutters
- dead wildlife which have fallen into the tank.
If gross contamination occurs (eg you find a dead animal in the tank), you should empty, clean, refill and disinfect your tank with chlorine