www.GymRatZ.co.uk wrote:

On 11/03/2018 08:56, Brian Gaff wrote:
Yes, most houses, including mine, around here have some lead piping and from
what I've heard from tests, there is very little lead in the water at all,
probably since its been here all that time its coated in some lime scale
anyway!

Ah the old "limescale stops lead" myth.

Just had multiple tests in the shop which has about 15m lead from meter
to tap.

First draw of the day was around 17 things and maximum limit is 10.
Flushed pipe was very low but subsequent test of flushed line then 30
minutes standing time before further sample gave around 12.
We're hard water but leaving water in lead pipe for only 30 minutes was
long enough to take lead content above maximum recommended level.

The story I heard was that lead dissolves faster in soft water. It may
possibly be a pH thing, as I think soft water is generally more acid. It
may be equally untrue, but it is different from the limescale
hypothesis.

--

Roger Hayter