depends on your local water supplier, But you have to hire/rent a metered stand pipe off them. severn trent charge £195.06 deposit, and £120.38 +vat for standpipe (assume thats per year) and then you pay for the water you use at the normal domestic rate per litre. So unless filling up at home is not an option there is not much point really IMO.
p.s these are 2007/8 figures I quoted so assume they will be more now.