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Septic tanks

Northern Ireland Water offers a range of discretionary desludging services to customers with septic tanks, domestic treatment plants and cesspools and who are not connected to the sewerage network.

What are septic tanks and cesspools?

  • a septic tank is a two or three chamber structure, which retains sewage from a property for sufficient time to allow solids to form into sludge at the base of the tank, where it is partially broken down by bacteria. The remaining liquid in the tank then drains from the tank by means of an outlet pipe and soakaway.
  • domestic treatment plants are usually specialist glass reinforced polyester (GRP) units purchased to treat effluent to a higher standard than that achievable by a septic tank alone. These units usually have moving parts or require compressed air and as such require electrical connections. These units like septic tanks also discharge through an outlet pipe and soakaway.
  • a cesspool is a sealed tank connected to a property by a series of drains. It collects the waste foul water from a property and when it is full it has to be emptied and the waste water taken away by tanker to a proper disposal point. Cesspools do not have an outlet pipe or drain.

Levels of Service

Ni Water offers the services below to customers not connected to the public sewerage system:

  • septic tank desludge. Includes removal and treatment of up to 4.5 cubic metres or 990 gallons of sludge within twelve working days.
  • domestic treatment plant desludge. Includes removal and treatment of up to 4.5 cubic metres or 990 gallons of sludge within twelve working days.

To request a desludge service please contact NI Water as follows;

  • Telephone: Waterline 08457 440088

Write to :

Northern Ireland Water
PO Box 1023
Belfast
BT1 9DG

Customers can request one free discretionary empty in any given twelve month period providing service conditions can be met. Should you require a second empty in the twelve months this will be charged.

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