Can you drink rainwater? Is it harmful or even healthy? All information at a glance.
No more lugging water crates, save tap water – and drink rainwater instead. At first glance, that sounds like a reasonable and sustainable idea. But is the result of a rain shower drinkable at all – or should one rather stay away from drinking rainwater?
Is rainwater clean?
To answer the question of whether rainwater is clean or polluted, one should consider the path that water takes before it ends up in the rain barrel: it evaporates from lakes, streams, and rivers and rises into the sky – where it condenses and falls back to earth as raindrops.
When the new raindrops form, the water is very clean: Because on its way to the sky it left all the pollutants and impurities on the ground – these did not evaporate with it. However, the same applies to nutrients such as minerals and trace elements.
On the way back to earth, the raindrops now have plenty of opportunity to collect dirt particles such as fine dust. This alone (depending on the environment and air pollution) may not pose a serious health risk; especially since we inhale the fine dust from the air anyway.
However, the condition of the rainwater is much more problematic if it has come into contact with plants, animals, or buildings on its way down – for example, if it has run through a gutter. Then it can contain pathogens such as bacteria.
Can you drink rainwater?
Rainwater is therefore cleanest when it is collected in a clean container without prior contact with plants, animals, or objects.
Rainwater can be drunk under these conditions, but it is not recommended in the long run. Tap water is strictly controlled according to hygienic aspects and is therefore the much safer alternative.
Due to the lack of hygiene, rainwater in Germany is not permitted as drinking water – i.e. not for cooking meals.
Making rainwater drinkable: how does that work?
However, for people who find themselves in an emergency, rainwater is still a safer alternative than water from lakes or rivers.
Then the following applies: collect the rainwater in a clean container – ideally so that it has not previously touched any plants or buildings.
If you have the opportunity, you can make the water even safer – this works by boiling it or with a water filter (if necessary, a coffee filter is also suitable for this).
Use rainwater in the house and garden
Even if it is not necessarily suitable for drinking, there are many sensible and sustainable ways to use rainwater. Perhaps the most obvious is to use as a garden irrigation water. The water can be collected in a (covered) rain barrel or a roof tank.
With a so-called rainwater utilization system, the rainwater can also be used in the house – depending on the storage size and amount of precipitation, for example for flushing the toilet and/or the washing machine.
With the latter, however, hygienic factors should be considered: when rinsing with cold water, germs from the rainwater can be transferred to the laundry. This can pose a health risk to babies, people with weakened immune systems, and the elderly.
So using rainwater for the house and garden makes sense and is sustainable – but you shouldn’t drink rainwater; at least not permanently.