i wouldnt bother, just hand over your whole bill and let the accountant sort it out he/she will just claim for percentage of it.
you can claim money back from your water company as the water you take away from your home will not go down your drain so you can claim that part of your sewage back.
BUT a word of warning if you go down that road your water company will more than likely charge you commercial rates.
i tried to do this but after many phone calls it started to turn into a nightmare so i just left it
Thanks for your promt reply Mark.
Some good points raised cheers.
My acountant has asked me to estimate the percentage of water used for my business and to be honest - I haven't a clue. I started producing pure water when I first moved in so I have no previous bill to compare with.
I think I will still install a water meter to keep an eye on useage etc. Will also help in calculating realist cost of producing pure water. I'm considering upping my prices and as i use 20 litres average per house I can see how my pricing is.
John