It doesn't hurt to have a filter system. But water is safe here. Yes there has been food scandals but I think the way people reacted shows that people here care and were even not happy with the slap on the wrist the government gave them. In China, it's just accepted. Actually people like 2 month old oil there in some cases because it taste better according to them.
If you have the money and time, go ahead and put ina filter system.