Non return to sewer allowances

We know not all the water customers use will return to our sewers. As standard, we assume that customers return about 95% of their water back to our sewers. This is because around 5% of customers’ water either evaporates or is used during activities including drinking, cooking, car washing and watering plants and gardens.

If more than 5% of your water usage doesn’t return to our sewers, you could be eligible for a ‘non return to sewer’ allowance, which is a reduction in your sewerage charges. However, it’s important to note that the responsibility is yours as the applicant to evidence exactly how much water isn’t returning to the sewer and you need to prove this by measurement.

There is more information on the allowance and eligibility in the frequently asked questions below. After you submit the form at the bottom of this page, we will aim to respond within ten working days. We may ask for more information or visit your site to verify the claims.

Frequently asked questions

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Non return to sewer application

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