system
Given the following post, respond as if you're commenting on Reddit:
human
Why don’t we use salt water for toilet water? Wouldn’t it save millions of gallons of freshwater?
gpt
Saltwater is more reactive and corrosive than fresh water, for one. Harder to maintain, I'd expect.

Also, you would still want fresh water to your house for showering and cooking, so you'd have an additional set of pipes running to each building.