Sustainable drainage systems – what you must do

You must not discharge any run-off from your site to public sewers surface waters or groundwater without consulting the appropriate regulator. If you discharge any run-off without consent or appropriate authorisation you may be prosecuted.

If you discharge to surface waters or groundwater you must contact your environmental regulator. If you discharge to the public sewer you must contact your sewerage provider.

In England, Northern Ireland and Wales you may have to include plans for sustainable drainage systems (SUDS) when you apply for planning permission for a development. It is considered good practice to include the use of SUDS in all development plans.

In Scotland all new developments must use SUDS to control surface water run-off to the water environment, unless the run-off is from a single dwelling or is to coastal waters.

You must have a licence from SEPA if you plan SUDS to control run-off from:

• a development with more than 1,000 houses
• a development with more than 1,000 car parking spaces
• an industrial estate
• major roads or motorways.

For all other developments, you may not need to contact SEPA, but you must comply with the requirements of general binding rules (GBRs) 10 and 11 of the Controlled Activities Regulations.

In Scotland, SUDS must be:

• designed to prevent pollution of the water environment
• designed to protect the bed and banks of the receiving surface water
• maintained in good order
• protected from materials that will damage or block the system.

If your site was constructed after 1 April 2006 you must not discharge untreated surface water which contains run-off from:

• fuel delivery or refuelling areas
• areas where potentially polluting materials, such as chemicals and oil, are delivered, handled or stored.

If you discharge surface water run-off from a construction site, you must make sure that you treat all surface water run-off using suitable SUDS measures.

If you cause or allow surface water or groundwater pollution you may be committing an offence and may be prosecuted and fined or imprisoned.

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 with oil, you may need to install an appropriate oil separator in the drainage system. See pollution prevention guideline (PPG) 3 for detailed guidance.

Store and handle materials carefully to reduce contaminated run-off from your site.

You should take care when you handle and store oil and chemicals, including fertilisers and pesticides. Make sure that you have spill kits on hand and that staff know how to use them.

Have a pollution incident response procedure for dealing with spills. Ensure your staff understand the procedure and know how to follow it.

Report pollution incidents to the incident hotline as soon as they happen on 0800 80 70 60.

PPG 21 Pollution incident planning (Adobe PDF - 318KB)

Ideally you should cover areas where potentially polluting materials are delivered, handled or stored to prevent run-off. Where run-off does occur you should:

• discharge it to foul sewer, with the agreement of your sewerage provider
• store it in a run-off tank for disposal by your sewage provider
• treat it appropriately before discharging it to the water environment.

Contact your environmental regulator to check if you can treat your run-off yourself before discharging to the water environment.

Where possible design SUDS to increase biodiversity and provide habitats for wildlife in the area they drain.