Final answer:
Distilled water and bottled water are both acceptable alternatives for drinkable water when the public water system is unavailable. Distilled water goes through a purification process, and bottled water is regulated for safety.
Step-by-step explanation:
For individuals living in areas where no freshwater is available, using distilled water is an acceptable source for drinkable water. Distillation is a process that purifies water by boiling it and then condensing the steam into a clean container, making the water safe for consumption. Other alternative sources that are commonly considered safe include bottled water from a reliable vendor, which is regulated to ensure safety and is typically free from harmful bacteria or viruses, and water from a tested, licensed source that has been certified as safe for drinking. It's important to note that while purified rainwater may be used in some instances, it often requires additional treatment to make it safe for drinking, as it can contain pollutants or pathogens.