I have encountered this guys too in Bradford, they came in and went down the basement to check my water connection. Then went up stairs and did some fake water test where the water changes colour. Funny thing is I just got a letter from the municipality saying beware of these guys and the top water is perfectly safe. ROFL sad part is a couple of my neighbors bought the service.
2006 M5 SMG III | Dinan Stage 1 Software
2003 Escalade 8 Seater of Fun - 232k and still running
2000 M Coupe