Why base sewerage charges on 95% of water used?

The 5% accounts for water not returning to the sewers such as evaporation, car washing, drinking, cooking and garden-related use including normal use of hosepipes, sprinklers, paddling pools and hot tub top ups. It also takes into account wet and dry years.

If you think less than 95% of the water you use returns to the sewer, you can apply to have your charges reduced by returning a completed non return to sewer form along with your customer reference number.