No one wants to drink water that could potentially harm them or their family. So it is quite understandable then that a commonly asked question is whether it truly is safe to drink rainwater stored in your water tank.
According to the NSW government’s BASIX website, rainwater stored in a tank is usable for flushing toilets, washing clothes, irrigating your garden and all other household uses. They then go on to say, “NSW Health does not recommend the use of rainwater for drinking purposes where a reticulated potable water supply is available.”
So what is the real concern here? The implications appear to be that rainwater stored in a tank is not safe to drink. Yet, rural Australia widely use rainwater tanks as a source of drinking water. NSW Health does not mean to say tank water should not be consumed. As they note in their own publication, Rainwater tanks where a public water supply is available:
A properly maintained rainwater tank can provide good quality drinking water. Occasionally there are cases of illness from contaminated rainwater. In urban areas the public water supply remains the most reliable source of drinking water for the community. In these areas NSW Health supports the use of rainwater tanks for non-drinking uses. NSW Health recommends that people use the public water supply for drinking and cooking because it is filtered, disinfected and generally fluoridated.
In other words, as long as your rainwater tank is properly maintained to protect water quality, then there is no reason why you and your family cannot enjoy non-fluoridated and unadulterated crisp clean rainwater. For more information, read our article How to Maintain Drinking Water Quality in Your Rainwater Tank.
Are All Water Tank Materials Safe?
There are a lot of rainwater tanks on the market made from different types of steel and poly plastics. Concrete tanks are normally used for underground and commercial purposes and can leak lime. This actually helps to neutralise the acidity of rainwater which can otherwise cause copper to leak into water that remains in the copper piping often used in plumbing.
The most common rainwater tank materials that you will see for urban tanks are either polyethylene or steel. Both are generally safe options, but many who drink rainwater from steel tanks notice that the water has a metallic taste. Steel tanks are often galvanised, being coated in zinc, to protect them from corrosion. Normally when the water tastes metallic it is the taste of zinc particles.
Today, many steel tanks contain a food-grade inner poly lining. This helps to prevent steel tanks from corroding as well as providing a more refreshing and crisp tasting water. Care must be taken when installing though to not damage this inner layer and they sometimes need replacing.
On the other hand, most Australian poly rainwater tanks are able to capture and store potable water—water safe for human consumption. They are usually made from 100% food-grade materials.
It is important to ensure that your poly tanks comply with the Australian Standard AS2070 ‘Plastics materials for food contact use’ as well as AS4020 ‘Testing of products for use in contact with Drinking Water’. This helps to assure you that the raw materials and final tank product have been tested to be safe for drinking purposes.
Finally, when drinking your tank water keep in mind that rainwater is more acidic. Such that when you turn on the taps to use your rainwater, and then turn them off, the rainwater will remain in your pipes. If your pipes are made from copper, then copper may leak into the water. You can avoid using this water by either flushing the first few seconds of drinking water out of your pipes or through installing filtration at your tap.
National Poly Industries manufactures poly water tanks that meet Australian Standards AS2070 and AS4020 ensuring water that will be safe to drink. If you have found this article helpful, and you are after a rainwater tank that can supply drinking water, then why not give National Poly Industries a call? Let us provide you with an economical option that will look great and suit your needs.