Non-return of water to the sewer

Last reviewed:

There can be a difference between the amount of water you use and the amount of wastewater you return to the sewer system. 

Our 'wastewater abatement allowance' takes these differences into account for our customers who have a water meter and can prove that over ten per cent of the water they use does not return to our sewers for treatment.

Our charges for wastewater services already recognise that up to ten per cent of the water you use may not be returned to our sewers, but customers who meet the criteria below can make a claim for an additional allowance.

Make a claim online

If you think you qualify for a wastewater abatement allowance, you can make a claim using our online form:

Make a wastewater abatement claim

If your water usage is complicated, you may prefer to download and complete one of the more detailed claim forms below:

Qualifying for the wastewater abatement allowance

To qualify for the allowance you should:

  • Have a metered water supply
  • Be able to show that more than ten per cent of the water supplied to your property is not returned as wastewater to our public sewer
  • Have at least 12 months of meter readings 
  • Be a named customer on the account

You will also need to calculate the monetary value of any of the water that is not returned to our sewer, using the leaflet below:

Water lost through leakage should not be included in any calculation of the amount of water that is not returned to our sewers.

We review all wastewater abatement accounts on a regular basis.

See also

Commercial allowances cover:

  • Manufacturing use  
    Where water is part of the product, such as soft drinks
  • Process use 
    For significant evaporation loss
  • Irrigation 
    For regular watering of sports fields or garden centres
  • Discharge to a private outfall 
    Where wastewater is not returned to a public sewer but to a watercourse, soakaway or similar

Domestic allowances cover:

  • Irrigation 
    Where a large amount of water is used to water a large garden
  • Use of swimming pools / ponds 
    When water is lost through evaporation
  • Discharge to a private outfall 
    Where water runs to a private outfall such as a watercourse, soakaway (or similar) but there is still a connection to our public sewer