Suppose that some type of disaster takes out the water supply. I’m not talking about a “boil 
water alert”, but a lack of water from your usual sources: tap water and bottled water. Maybe you have town water, and their system is no longer working from an extended power outage. Bottled water from stores will sell out in a matter of hours. You might have some bottled water stored in your home, but that will only last so long.
Where can you find drinkable water (called “potable water” after the Latin word for drinking)?
* Ice cubes can be melted for drinking water. Other frozen foods often have ice or liquid along with the food. And canned goods often have a fair amount of drinkable liquid.
* In winter, you can melt clean ice or snow, which should be pure enough to drink.
* Once the tap water stops flowing, you might try going to the basement and draining water from the pipes. To help the water flow, open some of the taps on the first or second floor of your home, to let in some air. Then take the water from the lowest point in the plumbing system.
* I would suggest NOT taking water from the hot water heater through. The water is at scalding temperature. If the power comes back on, the tank will be empty, but the heating elements may click on, causing a dangerous situation. You would have to fill up the tank with water before turning the gas or electricity back on for the tank. Not worth the trouble, in my estimation.
Some Unsafe Sources
- The radiators and hot water boilers for home heating systems that use forced hot water. This water circulates continually without being refreshed. It is dirty water, contaminated with heavy metals, chemicals, and who knows what else.
- Water from the toilet bowl or flush tank is usually contaminated with bacteria as well as mold or fungi.
- Water beds contain chemicals to keep bacteria and fungi from growing in the bed, making the water very unsafe.
- Swimming pool water can be used for personal hygiene, cleaning and for flushing toilets. But it is undrinkable due to the chemicals added to make the water swimmable.
- Lakes, rivers, streams, ponds, and standing water outdoors. Unless you have the water purification equipment to remove protozoans, bacteria, and viruses, it is not safe to drink.
I have a LifeStraw Family for water purification, but that is a topic for another post.
Thoreau
I have a question you might be able to help with. I have purchased 3 liter bottles of spring water. They have an expiration date. My understanding is that chemicals can leech out of the plastic and into the water beyond that date. Is there a way to make this water potable, beyond the expiration date? If not, would it be safe to use it for hygiene and laundry and washing dishes? Thanks in advance for your help!
I don’t think the expiration date is based on chemicals leeching out from the plastic. It has to be food-grade plastic, which is safe. Check the bottom of the bottles to see what type of plastic. The expiration date is not absolute. The water should be drinkable years later.