You can use sustainable drainage systems (SUDS) to treat lightly polluted water that runs off from your site, reducing the impact on the environment.
You must not use SUDS to treat sewage, heavily contaminated run-off or trade effluent. If you cause or allow surface water or groundwater pollution you may be committing an offence and may be prosecuted and fined or imprisoned.
You must consult with the Northern Ireland Environment Agency or Northern Ireland Water before discharging any run-off from your site to public sewers, surface waters or groundwater. If you discharge any run-off without consent or appropriate authorisation you may be prosecuted.
You may have to include plans for SUDS when you apply for planning permission for new developments. It is good practice to include the use of SUDS in all development plans.
If you discharge surface water run-off from a construction site, you must use suitable SUDS techniques.
SUDS good practice
Run-off from hard paving is likely to be contaminated by oil, organic material or toxic metals. Where there is a high risk of contamination by oil, you may need to install an appropriate oil separator in the drainage system - download guidance on the use and design of oil separators in surface water drainage systems (PDF, 79KB).
Where possible, you should design SUDS to increase biodiversity and provide habitats for wildlife in the area they drain.
For more information on measures to control water pollution, see preventing water pollution.