Given that lead-lined pipes, galvanised pipes and so forth are rarely used these days in the construction of homes, I was informed that is it still not recommended to drink hot water straight from the tap or even use it for cooking.

The reasoning behind this was that the large metal tanks / containers used to store and heat-up water in your home is prone to corrosion and the harbouring sediments, bacteria, heavy metals, etc over time. Another reasoning (more like a myth) is that certain chemicals have been added to the hot water system (district hot water distribution system) to help heat-up the water faster and retain heat longer.

Can someone who works in this industry or have expertise in this industry care to elaborate?