Thinking About Residential Grey Water

While working on using less resources as a family, we have mostly focused on reducing electricity and eliminating fossil fuels as a household. But here in Colorado, plain old water is actually becoming a scarce resource.

We dealt with this a little bit when we installed a DIY on-demand hot water reciculation pump in the master bathroom. And it looks like just that change reduced our water consumption by about 15% year-over-year. Once I had water conservation on my brain, I started thinking about reusing grey water. 

Grey water is typically sourced from bathroom sinks and showers, and clothes washers, usually requiring you to use specific soaps, shampoos and detergents. The grey water is then used to water landscaping or flush toilets.

Our drainage plumbing doesn't distinguish between sinks and showers vs toilets, so that's a non-starter forus. However, I do have several sources of "clean" grey water that currently go straight to a drain:

• Condensate from the ground-source heat pump
• Condensate from the Energy-Recovery Ventilator
• Drain from the clothes washer
• Drain from the (future) heat-pump clothes dryer
• Drain from the flush cycle of the water softener

Of these, the condensate drains are probably too miniscule to bother with, although I haven't actually measured. The really interesting one (to me) is the flush cycle of the water softener. Right now, all that water goes straight down the drain. In my house, I think I can plausibly use that water to help refill the toilet tanks in two bathrooms, with minimal plumbing work. I'll have to stick a bucket under the water softener flush drain and see what kind of flow rates I get, and how cloudy the water is.