Can someone tell me what this is in my tap water. Was boiling some tap water to make tea. Did this experiment 3 times thinking maybe my pot was dirty, but I cleaned and scrubbed it multiple times.

Had the water on a simmer for 15 min and these white particles were floating on the bottom. So I scooped them out and placed them in this glass.

Are these denaturated proteins? Is this unhealthy? Is this normal in tap water? (pic related)