We have a well (about 1200KM away from sea and 60 meter deep), the water when taken out has slightly dark color and has smell. But strangely in about 12 hours the smell and black color vanishes and water becomes odorless and clear without leaving any residues.
What can be possible cause, are there any known underground impurities that change with something like sunlight or air exposure?
Organic impurities and sulfides don't disappear like this, can someone help with details of this kind of water impurity.