Hi,
I live in London NW2 and twice a year a Thames Water engineer calls and takes samples of water indoors. Does a sample test on the spot and takes additional back to the laboratory, for, presumably more detailed testing.
The last visit in November 2008 was a 98.99% purity reading on the spot. Later confirmed in writing.
The last 6 years test results have all been virtually the same.
So credit where credit is due.
Pity some of the other service companies cannot even approach the standards of Thames Water.
Hope this answers your concerns.
Billbo