We just concluded the drilling of my house borehole and for the past four days

Change location

Change location as how

Change location as suggested.
The drilling engineer is supposed to consult a geo-surveyor before drilling the borehole.

Or, drill the borehole again by extending the dept to about 200meters.
I would suggested chemical treatment but I doubt it will work because you would need to constantly treat the water in the tank before use and that will require quality control.
Anyways, just consult a geographical surveyor. Or your municipal water agency.

ameddy1:
Change location as how

The water drilled at point A is always different from the water drilled at point B, even when they are of equal dept and in the same geographical location. Only that two water of the same dept range have the some similarities but are not entirely the same. A might be cooler than B, B might be more acidic than A hence the taste.
That is the reason he suggested you change location.

Find out from your other neighbours if they have experienced such

If yes, ask them how it was tackled

Keep draining out water for upto a week and see if it will go out

The last option is to dig another one in a different location in the same compound but a little bit far from the previous one but not close to the soakaway

There is a well in my neighborhood that has that mica as well