The joke about adding well water back in again at the end is "correct". Reverse osmosis removes 100% of the solids from the water, but drinking water usually contains small quantities of solids - you can see a breakdown on the label of some bottled water. Completely pure water would leach all of the solids that have built up on the insides of water pipes over the decades, and leaches away the protective oxide layer from metal pipework, causing it to corrode surprisingly rapidly. It also tastes pretty shitty - kind of "dead". So a small amount of high-solids water is mixed back in after RO to bring the water back to normal levels.

All that other shit in the diagram? No. Purification and treatment takes place after the mixing step, it would be crazy not to.

Least convoluted factorio seablock recipe

I'm going to refer to lakes as "cosmic ray sterilization basins" from now on.

Another article tag on explaixkcd that makes you go hmm 🤔😄

WATER. JUST PLAIN WATER. NOTHING DONE TO IT, JUST PLAIN WATER. POSSIBLY DRINKABLE. - Do NOT delete this tag too soon.

This is how I felt trying to build a water purification system in Oxygen Not Included

lol all that just to add well water back in at the end

Is this to scale?

What would be required for my wife to drink tap water.

Here’s an idea. Once you’ve already split the water molecules with electrolysis, you should throw those streams into separate mass spectrometers, but without the detector obviously. The idea is, that with ions flying in a magnetic field, their mass would determine where they land. Anything that isn’t the right kind of isotope, let alone right kind of atom, would be separated into the waste stream.