Drinking old water is generally safe if it has been properly stored. However, there are some risks associated with drinking stale water that has been sitting around for too long. This article examines whether it is ok to drink old water and what precautions should be taken.
How long can you store water before it goes bad?
If water is properly stored, it can last a very long time before going bad. The shelf life of water depends on the type of container it is stored in and the storage conditions. Here are some general guidelines for how long water can be stored:
- Bottled water – Typically lasts up to 2 years if unopened and stored properly.
- Filtered or tap water stored in food-grade plastic containers – 6 months to 1 year.
- Well water stored in food-grade plastic containers – 6 months.
- Tap water stored in glass containers – Indefinitely if stored in a cool, dark place.
- Distilled water stored in glass containers – Indefinitely if stored properly.
The key things affecting water’s shelf life are light, heat, and the possibility of chemical leaching from the container it is stored in. Glass and food-grade plastics are preferred over other containers. Keeping water in a cool, dark place helps extend its shelf life significantly.
Does old water go bad or make you sick?
Drinking expired bottled water or old stored water is generally not dangerous, but it can start to develop an off taste and odor. The main concern with old water is bacterial growth. Over time, bacteria from the air, container, or the water itself can start to rapidly multiply if the water is not stored properly.
Some of the potential health risks of drinking old, contaminated water include:
- Gastrointestinal issues – Diarrhea, vomiting, nausea from pathogens
- Respiratory illness – From mold and bacteria
- Chemical toxicity – From plastic chemicals leaching into the water over time
- Metallic taste – From metal containers corroding
If you notice any odd smells, tastes, or visible contaminants in old water, it is best to avoid drinking it. Trust your senses – if the water seems off in any way, play it safe and discard it.
How to tell if water has gone bad
Here are some signs that indicate water may have gone bad and is best discarded:
- Appearance – Cloudy, murky or discolored water can be a sign of contamination
- Odor – A strong, foul, musty or chemical odor indicates bacterial growth or leached chemicals
- Taste – A metallic, bitter, or odd taste can mean contaminated water
- Floating particles – Bacterial growth may create stringy material or film floating in old water
- Algae growth – Greenish tint and algae particles signal bacterial contamination
- Bottle collapse – If plastic bottles of water start to concave in shape, bacteria may have multiplied and altered interior pressure
- Expired date – If water is past the manufacturer’s expiration or recommended time frame listed for storage
Trust your senses – if water exhibits an atypical smell, taste, or appearance, do not drink it. When in doubt, throw it out.
How long does it take for water to go bad?
There is no set timeframe for how long water takes to go bad – it depends greatly on storage conditions. The warmer the temperatures and the more sunlight/UV exposure, the faster bacteria and chemicals can start to contaminate stored water. Here are some general guidelines:
- Bottled water – Can last up to 2 years before tasting “off”, but may still be safe to drink for longer
- Filtered/tap water – Starts to degrade in quality and taste after 6-12 months
- Well water – Can stay fresh for 6-12 months if stored properly
Leaving water containers open, exposing them to heat and sunlight, or contaminated storage containers can make water go bad much more quickly. The starting quality of the water also matters – high purity water like distilled or reverse osmosis lasts longer than tap water which contains more minerals for bacterial growth.
Will boiling old water make it safe to drink?
Boiling water can kill pathogenic bacteria and microorganisms that cause illness. So boiling old water may provide some benefit and make it safer to drink. However, boiling does not remove chemical contaminants or byproducts that can accumulate over time in stored water. So boiling may reduce microbial risks of old water but does not make it entirely safe or palatable to drink.
Additional steps would be needed to make old water potable after boiling:
- Filtering – With a high quality activated carbon filter to reduce off tastes, smells and chemicals
- Aerating – To improve flat, stale tastes from the boiling process
- Treating – Using distillation or reverse osmosis to further purify the water after boiling
If water exhibits foul tastes, odors or appearances – it may be best avoid drinking it altogether rather than trying to salvage it through boiling. The safest option is to start fresh with a new source of clean drinking water.
Tips for storing water long-term
Here are some best practices for storing drinking water long-term, so it stays fresh and potable for as long as possible:
- Use food-grade plastic or glass containers designed for water storage
- Wash containers thoroughly before filling with water
- Fill containers completely to minimize airspace
- Seal containers tightly to avoid airborne bacterial contamination
- Store in a cool, dry place away from sunlight and heat sources
- Rotate stock to use older water first
- Add preservatives like bleach in very small amounts to store water longer than 6 months
- Consider commercially bottled water or distilled water for the longest shelf life
- Replace stored water supplies every 6-12 months for best quality
How to safely reuse old stored water
While drinking old water is not recommended, stored water reaching the end of its shelf life does not have to go entirely to waste. Here are some ways to safely reuse old water:
- Cleaning – For washing surfaces, floors, windows, etc. Ambient temperature water works best.
- Toilets – Flush toilets as normal with stored water past its prime.
- Irrigation – Water plants, gardens and lawns. Avoid areas where chemical contamination could reach food.
- Pets – Use questionable water for pets after boiling. Monitor animal health closely.
- Cooler/Radiator – Top off non-drinking water coolers, radiators, or RV/boat water tanks.
- Fire prevention – Use for fighting fires or structural protection from wildfires if necessary.
Discard any water that has been potentially compromised, has strong odors or shows signs of algae growth. While most old water can be reused, it is safest directed away from consumption.
Frequently Asked Questions
Is it bad to drink water that has been sitting out?
It’s generally not recommended to drink water that has been sitting out uncapped for long. Exposure to air and contaminants can compromise the safety of water over time, especially if it has been more than a day or two. Longer storage starts to carry increased risks.
Can old plastic water bottles make you sick?
Yes, old plastic bottled water can potentially make you sick in a few ways. Bacteria growth inside the bottles can occur over time. Chemicals like BPA from the plastic can also leach into the water with prolonged storage and exposure to heat or sunlight. Experts recommend limiting bottled water storage to 2 years.
What happens if you drink expired bottled water?
Drinking expired bottled water is generally not dangerous, but can cause temporary digestive upset like nausea, bloating or loose stools. The plastic chemicals and microbial growth in old bottled water are the main risks. While not ideal, drinking a few sips likely causes no harm in healthy adults.
Can you drink water that has been in the car for months?
It is not recommended to drink water left in a car for months. The heat and plastic bottle degradation create high bacterial growth and chemical leaching dangers. The water would need to be boiled, filtered, and treated through multiple methods to potentially make it potable again.
Is it safe to drink water that smells funny but looks ok?
No, it is unsafe to drink water that has an odd or funny smell, even if it still looks visually clear. Odors indicate contamination and bacterial growth has likely occurred. Trust your nose – funny smells mean do not drink the water.
The Bottom Line
Drinking properly stored clean water is generally safe even past the manufacturer’s expiration date, but can have an undesirable taste. However, once water is exposed to air, heat, sunlight or improper storage conditions, bacterial growth and chemical leaching become concerns.
Watch for changes in taste, smell or appearance in old water. If in doubt, discard water reaching the limits of its shelf life. Boiling can kill some bacteria but does not remove chemical risks. The safest option for consumption is fresh water from a known clean source, ideally stored in food-grade containers and kept in cool, dark conditions.
