IELTS processes: a common (referencing) problem

"The diagram gives information about the process of making carbonated drinks."

Look at this part of the overview written by a student. Do you notice the problem?

1️⃣ "... a series of various machines, passing through which water is treated with some chemicals, carbonated and mixed with additives before it is ready for distribution."

What does "it" refer to? Water. The problem is what is distributed is not water.

Here is a part of another overview with the same problem.

2️⃣ "Before being packaged, water undergoes processing, which involves thorough purification, carbonation, and mixing with additives."

We don't have a referencing problem per se here, but the fundamental problem is the same: the subject for the first clause is "water," but it's not water that is packaged.

In processes, things change their state and turn into new things. Be mindful of the nouns, pronouns, and verbs.

Btw, how would you rewrite the first or the second sentence?