Geosmin is an organic compound that occurs naturally in the ground and is produced by a safe bacteria that is not harmful or toxic to humans in anyway.
Geosmin is what gives things like beets an earthy flavor.
Geosmin also causes what's known as Petrichor to happen when rain falls onto dirt after a dry spell when the dirt becomes disturbed.
Petrichor is that distinct smell that rain and dirt has after it rains.
If you have Geosmin in your drinking water then it's still very safe to drink.