Slugster, I had a water meter fitted a few months ago. I'd been putting it off for years because I thought you had to pay for it and that it would be hassle.
I logged the request over the internet late on a Sunday night and got a response back promptly telling me that the initial survey would be done in a couple of weeks but that the installation could take longer if I was on an old water pain. I suspected that our water main was old as the house is old, so was prepared to wait.
A few days later there was evidence that someone had been digging in the dirt/gravel track that is the access road to our house. There was a small hole (with evidence of a man hole cover) marked with fluorescent paint just outside our house.
It was probably about a month later when we noticed that the hole had been filled in and the next day we got a letter from the water board saying that they had fitted the meter and had adjusted ourpayments accordingly.
We too have seperate water companies for supply and waste. The supply company also contacted the waste comapny for us and we soon got a letter from them saying that they were reducing our bills too.
Fantastic service for something that I didn't pay for so therefore wasn't really in the water companies interest.