Why do we flush the toilet with clean water?

kitchen water might not smell too great if it sits for a while and rain water wouldn’t be reliable

Most municipalities don’t have grey water plumbed in—a few do, and use it for watering the lawn, toilets, and the like.

The longer term problem is that it increases the cost of the plumbing on both a house-by-house basis and citywide. However, it can be cheaper than alternatives.

Basically, what @grumpyfish said. It would require a second set of plumbing/grey water storage, and that would be expensive. I imagine that there are places where it has been done, either due to necessity or by a “green” homeowner with the money to burn on a custom plumbing system.

I don’t know the reason, but I do know one good consequence of not using grey water in the toilet: if there’s an emergency and the water is shut down, you can drink the water in the toilet tank (not the bowl—that’s full of bacteria).

Because we can. It’s convenient, and water is so (seemingly) plentiful, we take it for granted. In fact, we flush after every pee. In other places where they know how scarce and precious water is, they keep a bucket of grey water nearby to flush, and only after #2s.

There are some places using recycled water, especially high rise buildings using it for toilet water.

Because that is the most easily attainable solvent that will promote sanitation.

Some of the rest areas around here use recycled water. It is blue so I assume they try to deodorize it in some way. Could be wrong. It still kind of smells bad, but I’m not in there long enough to be terribly bothered. I would not want that smell in my house, though.

I don’t think most people would want raw sewage used to flush their toilets.

@Pretty_Lilly For the record, it wouldn’t be raw sewage. The basic idea is that water from sinks and showers, but not toilets, goes through a basic filter, but not full treatment before being used for purposes like toilet flushing, irrigation, etc.

For the same reason we water our grass with clean water. We didn’t build our infrastructure to transport potable AND non potable water to the places we need it, so we clean ALL the water even though it doesn’t ALL need to be clean.

@Snarp—Rainwater is a good use for this, and some people have catchment basins on their drains for at least watering the lawns.

Getting that water pressurized to do toilets and such is difficult on a small scale, you could either use an accumulator on the line (along with a pump), or put a tank on the roof (or in the attic!), that you’d need to pump into.

Anyway, these are all under $500 options, and would easily save you that much in water bills depending on your area & amount of rain. Were I to do this, and capture 50% of my roof area into a catchment, I could theoretically capture 20k gallons of water a year. If I were able to hold all of that water, and use it as greywater in my toilets. In theory, I use around 10k gallons of water in my toilets each year, so that would be my savings (theoretically).

10k gallons is around $75 a year, so my $500 pump/tank system off my roof drains would be paid back in around 6–7 years.

Some people do have rainwater and greywater recycling. Greywater may need treatment due to soluable matter that could cause plumbibg problems and odors

would you want dirty water splashing back at you? ~

You might be interested in the AQUS water capture system.

It only costs $295 and is easy to install. It typically saves 10–20 gallons of water per day. It works by capturing water from your sink and then filters and disinfects it to be reused for toilet flushing.

@casheroo By the time you’ve peed or pooped in it, it’s all dirty water anyway!

The recycled water service is not available through your municipal agency, but most allow for the installation of your own system in your house.

When the city we lived put severe restrictions on water usage, we simply recycled our own, by using a bucket to carry ‘used’ water from the kitchen to the bathrooms.

It’s too expensive and unreliable to try to use rain water or waste water. And the bugs, and the smell…