You have to use loads to go on business tariff, we use £8500 a year and were not on business tariff, you can ask for a supply that is water only no sewage so its cheaper, we have rainwater tanks 26,000 litres each same size as an artic tanker. The pig farmer at the back of us is on business tariff though he uses 1/2 a million litres a month. Ours is the dearest water in the country and it's still only 2p for 10 litres, so 30 chickens cost 2p a day, a horse 4p, a pig 8p we supply all the animals/veg from rainwater its the 6 hot tubs and the 600 guests a year that use all the water. Think yourself lucky, I'll swap bills anytime you like.