We recommend storing nine litres of water per person in the household to meet basic needs. If you follow the advice in this article, the water can be stored for years and still be safe to drink.
To ensure the water stays good, wash the bottles or canisters with soap and water and rinse well. Then fill with water and add two capfuls of household bleach per 10 litres of water. Leave to stand for at least 30 minutes, then rinse thoroughly.
Once the containers have been cleaned, fill them completely with tap water. Let the water run until it is cold before you start filling the containers, to ensure the water you store is “fresh”. Warm water is not recommended as drinking water, as warm water can contain metals from the pipes.
Water should be stored in a cool, dark place away from direct sunlight. Sunlight and heat can slowly break down plastic containers, giving the water a funny smell and flavour. It can also lead to algae growth.
Do not store water containers in a room where petrol, pesticides and other similar substances are stored, as vapour from these chemicals can penetrate plastic.
Sub-zero temperatures cause water to freeze. This may spoil a full bottle, even though the water quality will not necessarily be affected.
If water is stored in properly cleaned containers and the water is of good quality – as most Norwegian drinking water is – it can be kept for years without becoming unsafe to drink. Over time, however, substances from plastic containers will leach into the water. This will affect the flavour of the water, although the water will still be safe to drink.
To ensure a normal flavour, the water should be replaced once a year. You could also consider storing water in glass containers. Glass is more impermeable than plastic and less vulnerable to odour penetration. However, a slightly odd taste or smell will not affect your health.
You can also buy pre-bottled water for storage. The best-before date on shop-bought water indicates until when the manufacturers can guarantee the contents. The fact that water gets a funny flavour because the bottle is not quite impermeable – and plastic can affect the taste of the water – does not mean that the water is unsafe to drink.