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Comment by loeg | Hacker News Reader

The absolute strongest complaint is that DCs consume treated, potable water, which is less abundant / easily re-created than any old non-potable source. (Of course the easy solution here is DCs just ingest / treat their own non-potable source. Or utilities charge rates sufficient to price in the externality of drawing down more potable water. The economics still work for DCs if they need to treat their own water -- the fundamental problem is that utilities are underpricing their potable water, so DCs prefer it all else being equal.)

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Why don’t data centers use gray water more often? Wouldn’t that be better for basically everyone?

My guess is it’s some combination of the infrastructure not existing, the distribution being bad, and the treatment costs not penciling out.

But that feels like the kind of thing municipal utilities could solve with pricing. Potable water should probably be priced differently for residential use than for big commercial/industrial users, in a way that pushes them toward non-potable sources wherever possible.

A fun Texas water fact I always bring up: the entire state’s monthly freshwater use is roughly a week of freshwater inflow into the Chesapeake Bay. Texas would be the 8th-largest GDP in the world if it were a country, and its whole monthly freshwater demand is basically a few months of water that the Chesapeake just dumps into the ocean. (Of course, estuaries make use of the water so it's not just wasted but it's illustrative imo)

Another fun comparison point is yearly Texas uses 0.08% the volume of the Great Lakes in freshwater but ~ 30-50% of the volume of all the lakes in Texas.

We've got a lot of water but it's not distributed evenly and we should probably build some sort of water pipeline eventually so water rich states can sell to water poor states.

Again, this is all just speculation by someone who knows not a damn thing about municipal water management.

> Why don’t data centers use gray water more often?

DCs will just use the cheapest source that meets their needs. If they have to treat greywater and that costs more than municipal potable water, they'll use the potable water. (In part this is utilities selling their potable water too cheaply.)

> Wouldn’t that be better for basically everyone?

No; if it was cheaper for DCs, they'd already be doing it. But it isn't an insurmountable cost -- DCs still pencil with slightly more expensive cooling.

Why do they even need to treat the water? Surely all they care about is that it’s a cold liquid?

They need it to not clog up their cooling loop, corrode fixtures if the pH is off neutral, etc. It doesn't need to be potable.

Those of us by the Great Lakes would prefer that our water not get sold to other places, thanks.

Not all of us. I'm totally fine with water pipelines in exchange for long distance transmission lines for solar power and other such infrastructure like gas pipelines from areas that produce stuff we do not.

Export an abundant resource for a scarcer one seems win/win to me. Kind of the point of interstate commerce.

In my corner of the Great Lakes, we have so much excess natural gas that it is actually being sold for negative prices. So a pipeline to ship natural gas out would be good, but we certainly don't need any pipelines to ship it in.

There is also an excess of electricity (thanks to gas peaker plants), so there are lots of transmission lines being built. (My property has an old transmission line on it, and then a new one perpendicular to that, solely built to try to do something with all the excess gas and then excess electricity being generated.)

So with that in mind... we'd probably rather our lake doesn't get drained, thanks, and is just left the way it is.

Long term, fresh water as a resource is in decline [0].

[0] https://science.nasa.gov/earth/earth-observatory/global-fres...

DCs could desal all of their cooling water from saltwater and it would still pencil. (So could residential water, for that matter.)

They could but that’s more expensive and location dependent. Much cheaper to put the externalities on tax payers and use their potable drinking water at a nice discount. Best: you don’t even have to report usage.

Thankfully the Great Lakes Compact prohibits water from being diverted outside the great lakes drainage basin, with very limited exceptions.

https://www.glslcompactcouncil.org/program-areas/water-diver...

Why? We have 27 quadrillion gallons in lake michigan alone. You could pump millions of gallons a day out and if it just stopped raining it would take 3 million years to drain it. Stop listening to Charlie Berens.

For reference, Yuma uses around 100 billion gallons of water a year for irrigation. The whole state uses around 2.2 trillion gallons per year.

That's 6 billion gallons a day. And if there were a supply of lots of fresh water, you could expect the consumption by agriculture in desert areas to go way up, so yes, it is entirely possible for lakes to get drained by schemes like thus, such as the Aral Sea disaster. Lake Chad and Lake Poopó are examples from two other continents of the same level of destruction.

Sorry but that isn’t your water. Do you own the Great Lakes?

The Great Lakes are part of the United States and Canada. If the United States or Canada would like to repurpose the water within them for some better use then that sucks for you

I one of those people that think that natural resources should belong to the people who customarily reside in an area and have an investment in its long-term health, both of the people in the area and also of the environment.

Draining the Great Lakes is not a good idea.

You’d have to convince a majority of the members of the Great Lakes-St. Lawrence River Basin Water Resources Compact. Good luck with that.

Grey water would normally get treated and then discharged into a river or lake or other local water body. If you evaporate it at a data center, then you break that local loop. It's really only different from using potable water in that you save a bit on the expense of fully treating it.

Using 1/4th the entire freshwater inflow into the Chesapeake Bay makes it sound enormous. That's multiple major rivers for a bit over 30 million people.

I live near the Potomac and always figured the region was wet enough that water was not a concern. You have me rethinking that somewhat.

Where does your gasoline come from? Most of that usage is for the massive Exxon/etc facilities we have in Houston/Galveston to refine most of the fuel the entire nation uses.

Interesting! What do refineries use so much water for? I had no idea.

By and large cooling, just like a data center.

Grey water from where?

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