The answer depend on if it is a city system or a private well.
There is the Nile, the Blue Nile and the White Nile. There was a Yellow Nile but no Black Nile. However the Ancient Egyptians sometimes called the river Ar or Aur (black) because of the colour of the sediment left after the river's annual flood.
Check the connections on your water heater. Some flex connectors have a black washer like substance that breaks down and goes through the water system
Yes. They are sometimes black.
The water was most likely black because it was carrying a lot of sediment. Much of the rock in Japan is basalt, which is usually black.
because of the black sediment left after fllods
sometimes
Something is wrong in your pressure tank, possibly waterlogged and rusting.
aloes normally have short, hard (sometimes black) spines on the leaves and sometimes the stems - although they cannot really be likened to black thorns
sometimes but not usually.
Sometimes
Sometimes a different shade of black.
are you still seeing this? I started to see the thread like black string in my right eye. Sometimes its there and sometimes its not.