What is the deal with lead in the water?

[Zaz]

As a newcomer to Hamilton, I learned about the kids' testing for lead last year in lower Hamilton and how astonishingly little was publicized about the process and findings. My neighbour says the testing itself was not metioned in schools and most parents did not know to bring their children in for testing.

What is the scoop on this? Is there a real danger? Is someone trying to keep a lid on the issue? Are some of the water mains really made of lead? What kind of filtering solutions do you have setup in your house, if any?