NI Water provides desludging services to householders with properties that aren’t connected to the mains sewer. These properties use septic tanks, domestic treatment plants or cesspools to receive domestic waste. Householders can have one free desludge in twelve months.
What a septic tank does
A septic tank is a two or three chamber structure, which retains sewage from a property for enough time to allow solids to form into sludge at the base of the tank, where it is partly broken down by bacteria.
The remaining liquid drains from the tank by an outlet pipe and soakaway.
What a cesspool does
A cesspool is a sealed tank connected to a property by drains. It collects the waste foul water from a property. When it is full it has to be emptied and the waste water taken away by tanker to a disposal point. A cesspool doesn't have an outlet pipe or drain.
NI Water provides two desludging services to people in properties that aren't connected to main sewers. They can offer:
- septic tank desludge to remove between 1 and 2.5 cubic metres of sludge within twelve working days
- domestic treatment plant desludge to remove between 1 and 2.5 cubic metres of sludge within twelve working days
You are responsible for maintaining the septic tank and connecting pipes. NI Water doesn't clear blockages in pipes connected to a septic tank, or repair tanks or lids.
Requesting a desludge service
You can get one free desludge in twelve months if your property and septic tank meet certain access and safety conditions. If you give incorrect information, NI Water won't do the desludge but will charge for visiting your property. NI Water charges non-domestic customers for treating and removing sludge from septic tanks.
To ask for a desludge service, contact NI Water:
Ordering a second desludge
If you want a second desludge within twelve months, you need to pay for the service. To find charges that apply to domestic septic tanks, go to section eight in the Scheme of charges: