Is it safe

May or may not be potentionally damaging. Personally, I would not drink tap water.

As I know, if you want to drink it directly, it can't be. It differents from in Japan. However, some people around me, use it to cook something and they feel safe. Sorry, I couldn't reply it scientificly. Yet, I usually consume water from an electrical water purifier, whether to consume directly or cooking.

In Korea some cities have heavy metals in tap water. better to avoid directly using tap water for drinking..