While in Hong Kong we were advised not to drink the water, so be prepared to spend some money! Water wasn't overly expensive but if you are trying to keep to a tight budget it could be difficult.
Every morning before the days march around Hong Kong, the first stop was the supermarket to get water. Buy plenty because you will need it.
the water supply in hong kong is quite clean, but a tourist may not get use to it !! so, boil the water before u drink , or just simply buy some distillated water to drink !!
* the pic shows one of the reservoir in hong kong which is called ' Tai Lam Reservoir'
I never came across any dangers but drink only bottled water, even at the best hotels. Also, I didn't feel to comfortable about eating at KFC so I didn't (call me paranoid but it's better to be safe than sorry)