Most of Australia's drinking water is by nature soft, acidic and corrosive. Chlorine is also acidic and corrosive. When you add the two together you get a powerfully corrosive mixture that is not easy to manipulate or control. One consequence of this is the increasing occurrence of so-called "blue" water, telltale symptoms of the poisonous corrosion of copper water pipes. Corrosion of domestic copper plumbing is now a serious heath problem, in the eastern States. These residues, caused by the action of acid water on copper and brass, can have significant long-term health effects on children including impaired intellectual development.