portable, potable

Portable or portable describes something that can be carried from place to place, or that is easily moved or transported--
The power company loaned us a portable generator, so we won't be left in the dark.
There are portable toilets at the entrance to the fairgrounds.

Potable or potable describes water that is suitable for drinking--
We won't be able to continue our hike if our supply of potable water isn't adequate.
A shortage of potable water is still one of the most serious problems on the planet.

Now that you know that, you can say--
"We can use this portable water purification system to make our own potable water."

Note--"portables" means more than one moveable item, as opposed to a permanent or installed item.  "Portables" might be used in a job or profession where things are frequently referred to in this way--
Are those permanent classrooms, or are they portables?
Note # 2--"potables" is an old-fashioned term for drinks, now used in a humorous way--
Let us aquire some potables and quaff them in our dwelling place.