I'd have a look at this first.

http://dwi.defra.gov.uk/consumers/advice...s/lead.pdf

It confirms that the coating of limescale in a hard water area is a form of protection. Also, see the reference to getting your water company to take a sample free. Anyway there is enough water flowing down the gutters for sampling, courtesy of Thames Water's incomparable maintenance of the mains.

This post was last modified: 06-02-2017 12:25 PM by Theotherbrian.