Water and sewerage charges for businesses

Sewerage charges for businesses


Businesses must pay charges for foul sewerage and drainage. Sewerage charges have two elements:

  • a standing charge
  • a variable charge

Measured charges for sewerage

For customers billed on measured charges, the variable charges are based on the amount of water used with an allowance for water which does not return to the sewer. Standing charges are added based on the size of their water supply pipe. The standard non-return to sewer allowance is 5 per cent. Businesses who can show a higher non-return to sewer can apply for a different allowance.

Domestic allowance for measured sewerage customer

If you pay business rates, you may be able to apply for a domestic allowance of 95m³ every six months. This allowance is subtracted from the volume recorded on the meter. It is worked out for the exact number of days covered by the bill. Customers wishing to apply for the domestic allowance should contact NI Water. Proof of your rateable status may be required to confirm eligibility.

Read further details on understanding your bill and NI Water's charges.

Unmeasured charges for sewerage

For unmeasured customers, the variable element is based on the rateable value of the property with a standard rate standing charge.

Assessed charges for sewerage

Where it has not been possible to install a water meter, you can request an alternative assessed charge for water and sewerage. The assessed charge includes two elements: a standing charge and a variable charge based on the loading units attributed to the water using appliances on your property. You can apply for a domestic allowance against assessed charges if you pay rates.

By reducing the amount of water your business uses you can lower your water and sewerage costs. See reduce your water, sewerage and effluent costs. Water saving tips for businesses.

If you want to discharge anything other than clean water into surface water drains or watercourses you should check whether you need permission from the Northern Ireland Environment Agency. See preventing water pollution.