Might want to hold off on telling people that you were thirsty and drank a tall glass of Jill: https://www.urbandictionary.com/define.php?term=jilling

We call it Corporation Pop here.

For sparkling, it's commonly referred to as "homeopathic lager" among colleagues - i.e. without any active ingredients.

Desalinated saline

Liquified comet farts

Council pop

I call it life juice

I could sure go for a ice cold cup or H2O.

Gemeentepils in the Netherlands. Municipality beer.

Molten ice.

In Chicago you sometimes get a “Lake Michigan on the rocks”

Council Pop

In Germany, we do have some nicknames especially for tapwater: I personally know of Leitungsheimer, Kranwasser and Kraneberger

I call sparkling water "Sparkle Boys" does that count?

Adam's ale. What my grandpa used to jokingly call it. Edit: someone beat me too it.

https://en.wikipedia.org/wiki/Adam%27s_ale

“Now that’s good quality H2O”

H20?

"Worter sip" in these parts.

Some southern Slavs call tap water "technical" because it's technically safe to drink, but definitely has a lot of stuff in it that you don't want to drink... You complain as you chain smoke.

Adam's ale (also referred to as Adam's wine, especially in Scotland; sometimes simply called Adam) is a colloquial allusion meaning water. It alludes to the idea that the biblical Adam had only water to drink. This inference gained popularity around the beginning of the 19th-century temperance movement.

Council pop is such a term, but is very UK.

I don't touch that stuff, fish fuck in it!

Clear

A cup of Jack. As in no flavor. Because some dumbasses think that about water.

A glass of some High Koala-Tea H2O courtesy of The Waterboy

Give me a cup of wet

H20, Agua

Although i know the implications of calling it Jill.