It depends on the Plumbing in your building, but in the States its usually as clean as what comes out of your kitchen faucet.
I am not sure about gas or oil. A foul odor could be from the sewer system. All of the drains in your home have a trap that keeps water in the pipe. This water prevents sewer gases from coming into the home. If you pour water into each drain (sinks, tub, shower, toilet, and any other drain in the home), you may find that the smell goes away.
A water shortage that goes on for several years is referred to as a water crisis.
the swimer
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basically it evaporates into the sky, eventually becoming rain/snow and falls back to earth. It rises into the atmosphere.
Dirty water typically goes to wastewater treatment plants, where it undergoes various treatment processes to remove contaminants before being released back into the environment (such as rivers or oceans). Properly treated dirty water can then be reused or returned to the natural water cycle.
because before it touches the water or goes under water u can smell it. or maybe underwater the poop has farts
the reason why the toilet makes noise when you turn water on is because all the water lines are conected so when you turn on water the toilet gets affected and the water that goes down a drain goes to the water pipe.
clean water is naturally dirty, it goes through a process in which then it becomes clean.
the water will become dirty
It all goes to the same treatment plant and is sent down stream to the next town or city. All tap water is the same, sink or toilet.
All waste water travels to a water treatment site through underground pipes and is filtered clean before being released.
Goes straight to sewer
Under what circumstance? New toilet, when you turn the water on, water goes down the overflow tube to fill the bowl. You don't have to flush it the first time to fill the bowl.
That there either one curious or your not giving them enough water.
I personally think the sewer line also your toilet water goes there.
either right below the toilet or if you want to shut it off before that valve you have to shut off the water before it goes into the house.Depends on the type of "toilet"A tank and bowl or a one piece normally has a shut off on the left side below the tank.A flushometer type has either a knob or an angle valve that needs a flat screw driver to shut it