Potable and portable are easily confused words. The spell-check of most word processing software programs would not catch a slip-up among these three words. As long as it’s a word and it is spelled correctly, spell-check keeps on scanning the document.
Potable is an adjective. It means drinkable, and is used to describe water.
Potable can also be a noun, and it refers to any beverage. When it’s used to describe other beverages, the potability isn’t so much about safety, but about whether the drink has a favorable taste.
Portable is an adjective, it means movable, or capable of being physically moved from place to place.
The following sentence uses both words correctly:
In a drought or when a water supply is contaminated, accessing replacement water that is portable and potable are crucial matters.