Question

what is the mixture of greenish deposit on taps and pipes

Answer 1

1- moss

2- lichen

3- dartre

4- flustra

Answer 2

The green stuff is cupric chloride, a byproduct of corrosion of the valve body or possible copper leachate in the water. Either way, it's typical of water leakage where the water is of low pH. The white stuff (sometimes feels fibrous like cotton candy) is just efflorescence