I drink distilled water all the time, it's not toxic in normal quantities.

Ok, fair enough, but if that's all the water you drink than you will have to get a bunch of minerals elsewhere in your diet.

Here: https://naturalhealthfundamentals.com/is-distilled-water-saf...

it says:

Those who may need to be cautious when drinking it:

* Anyone who is already deficient in minerals. You may be someone who would benefit from the little extra minerals water can give you. Although if you are already deficient in minerals, and have health issues, make sure to get your water from a good source to avoid all the chemical additives from most tap waters.

* There also isn’t much information on how well we absorb inorganic minerals from water. There is also the possibility that the minerals present in the water are not doing us much good. But since it could be helpful it probably doesn’t hurt to have the minerals there.

* Someone who has health issues or malabsorption problems.

* Anyone who has an extremely poor diet and doesn’t get many minerals from their food should remineralize distilled water if they are drinking it.

It is my understanding that it is incredibly difficult to keep water pure. Transporting it any amount of distance from the source is likely to leech quite a few minerals from the available pipes.

Sorry, what? Pure water isn't toxic. And you can get minerals from other sources.

That's like saying tap water is toxic because it doesn't contain a balanced diet of vitamins.

Distilled water isn't toxic per se, but it's definitely got harmful effects. It'll leach minerals out of your teeth, for instance.

Just add some artificial minerals, it can come in some powder form I guess.

A few years back Coca-Cola got in trouble by doing exactly this. What they were doing was taking tap-water, and purifying it so they could sell it as "Dasani" - not a mineral water product, exactly, but a "lifestyle drink" they called it.

The thing about water when it's pure enough is that it's remarkably odd. It's unpleasant stuff: it'll weaken concrete if it leaks onto it, apparently it'll damage brass and steel, and it'll leach the minerals out of your teeth, but only until the water is no longer pure enough to do so. So what people do is, as you say, add buffer minerals back into the purified water to take the edge off.

What Coca-Cola got wrong was the dosing: they put ten times the amount of buffer minerals into the water as they should have, and made it toxic. So they'd taken a perfectly safe tap-water supply and ruined it.