When I moved into a brand new apartment in Manchester two years ago I got my first water bill when, after a few months, they got round to switiching the meter on. I'd never had one for any other address, so I didn't know what to expect.
It was for £121. For 3 weeks. For 54 cubic metres of water. That seemed a lot but I couldn't really visualise how much water I'd been using.
Then I read that they assume that the amount of sewage you produce is equivalent to the water consumption. Fair enough, I wouldn't want to have my sewage actually metered!
Now by my reckoning a cubic metre is about 4 wheelie bins. Possibly a bit more.
I can be fairly certain that, living on my own, I did not generate 4 x 54 wheelie bins worth of waste in 3 weeks.
So Chris, in your case 8 wheelie bins in 3 months? Baths / showers / loo flushes / shaving / tooth brushing / washing machine?
Might be a bit on the low side ...... but maybe you are just very frugal.
BTW - My own bill was reduced to a more reasonable £12.75 when I queried it.