How does tap water stay clean in dirty pipes?

Question

Recently we had a plumbing problem with our dishwasher and while we were disconnecting the pipes under the sink we saw the gross crud in the plastic pipe tubing. So how do we get clean water to drink?

Answer 1

Maybe you don't .. but since the water is moving your water picked up very small amounts...so small you could not see it with the naked eye.

However,it was present if the water ran through those pipes the water contained everything the pipes did ...just in small amounts.

Answer 2

you had gross crud in the water pipes or the drain pipes ?  you shouldn't have crud in the domestic water pipes , in the drain pipes is normal and they aren't connected in any way

Answer 3

In plastic waste lines, which are usually larger pipes (1.5" and above) you will certainly find a build-up of crud.  From a kitchen sink, especially, you might get a jelly-like buildup of greasy, fatty, soapy slime... grey in colour.  This is natural, in a way, but if it gets too thick it might block the flow.

In water supply lines you can get build-up also.  In an iron pipe, you can have 'iron bacteria' which will create some slime, and also release an odour.  In a copper pipe you can get a build-up of corrosion and corrosion by-products, mostly combinations of copper and other minerals which are in the drinking water.  The chlorine in the water system (if you have city water) might make this problem worse.  

Don't drink the water out of the waste lines!!!  And don't connect them to the water supply lines by accident, either.

Do drink the water from your corroded copper supply lines.  The minerals and copper won't harm you.