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Water run-off from construction sites

We are now able to accept pre-application proposals, new applications, variations, transfers and surrenders.

We would strongly encourage pre-application enquiries prior to submitting applications. Please submit these by email to waterpermitting@sepa.org.uk

What should you do now?

Email application forms along with supporting information to registry@sepa.org.uk

Submit enquiries about General Binding Rules, existing authorised sites and maintenance via our online form: Contact us

Water run-off from construction sites

The discharge of water run-off from a construction site can cause pollution of the water environment. As such, any discharge of water run-off from a construction site to the water environment must be authorised by SEPA.

Water run-off includes any water from rainfall (or any meltwater from ice or snow) that flows over (or horizontally through) the surface of the ground and any matter (for example soils) that are picked up by that water as it does so.

Construction includes any land preparation, demolition work or ground remediation required prior to construction taking place.

Authorisation requirement

Levels of authorisation:

There are two levels of authorisations that apply to the discharge of water run-off from construction sites to the water environment:

1. General Binding Rule; or

2. A licence.

The type of authorisation that you require depends on the scale of the construction site itself. Further information on the levels of authorisations can be found in the CAR Practical Guide.

Licence:

Construction sites that discharge water run-off to the water environment and:

a) cover an area greater than 4 hectares; or

b) contain a road (or track) greater than 5 kilometres in length; or

c)  include any land with an area greater than 1 hectare that has a slope more than 25 degrees; or

d)  include any road (or track) with a length greater than 500 metres that has a slope more than 25 degrees

will be authorised under a licence. You must apply for, and be granted a licence, before the activity can take place.

General Binding Rule:

Construction sites that discharge water run-off to the water environment and are below the licence level thresholds are authorised under general binding rule 10 of The Water Environment (Controlled Activities) (Scotland) Regulations 2011 (as amended).

You do not need to apply to, or notify SEPA, provided your construction site meets the requirements of GBR 10 - these can be found in the CAR Practical Guide.

Phasing of construction:

If you are phasing construction work across a construction site, the discharge of water run-off from a construction site to the water environment can be authorised under general binding rule 10, provided that:

1. the distinct phases remain below the thresholds for a licence;
2. all construction work is complete before any construction work (including land preparation) begins in the next phase;
3. that no water run-off from a ‘live construction’ phase drains to (or through) a completed phase; and
4. the final sustainable urban drainage system (SUDS) is fully operational for the completed phase;

Where the above requirements are satisfied, general binding rule 10 will authorise the discharge of water run-off and you do not need to apply to, or notify SEPA. General binding rule 10 can be found in the CAR Practical Guide.

How to apply for a licence:

To apply for a construction run-off licence you must:

1. Complete application form A;

2. Complete application form N; and

3. Pay the appropriate application fee.

Licence charging:

The charging (both application fees and ongoing annual subsistence fees) for a construction run-off licence is split into two bands:

Charging band	Thresholds	Application fee	Subsistence fee
Construction run-off	Construction sites that discharge water run-off to the water environment; and a)  cover an area greater than 4 hectares; or b)  contain a road (or track) greater than 5 kilometres in length; or c)  include any land with an area greater than 1 hectare that has a slope more than 25 degrees; or include any road (or track) with a length greater than 500 metres that has a slope more than 25 degrees	Fixed fee. Refer to our charging scheme for latest fees – activity 10080 (any other CAR activity subject to a simple licence)
Large and complex construction project	Projects that undertake one or more controlled activities (including the discharge of water run-off from a construction site to the water environment) and are: a)    A project (or part of a project) that is a National Development, as identified in the National Planning Framework; b)    An onshore electricity generating station, wind farm or power station with a capacity of greater than 50 megawatts; and / or A linear project greater than 25km in length.	Charged on a time and materials basis. Refer to Section 3.4 of our charging scheme guidance for further information

 

Discharges to Scottish Water assets:

Where you intend to discharge all the water run-off from your construction site to a Scottish Water asset, there is no need for you to hold a SEPA authorisation. A Scottish Water asset can be a combined, foul or surface water sewer.

Please note that any discharge to a Scottish Water asset requires permission and a separate authorisation from Scottish Water. Further information on Scottish Water’s requirements can be found on their website: Trade Effluent - Scottish Water

Where Scottish Water do not authorise the discharge of water run-off from a construction site to their asset and you are required to discharge to the water environment as a fall back, you must apply to SEPA for an authorisation.

Where do you discharge to?	SEPA authorisation required?	Scottish Water authorisation required?
Discharge only to the water environment	Yes	No
Discharge only to Scottish Water asset	No	Yes
Discharge to both water environment and Scottish Water asset	Yes	Yes

Chemical treatment:

We discourage the use of chemical additives (flocculants, coagulants or other settling / clarifying agents) to treat water run-off from construction sites as a primary measure. The use of chemical additives to treat water run-off from construction sites presents a high risk to the water environment given the presence of heavy metals and / or hazardous substances.

We expect passive (and / or mechanical) treatment systems to be used where possible, and chemical treatment only to be used as a last resort. Where any operator wishes to use chemical treatment, they must provide robust justification. The justification must be based on an assessment of site-specific factors and conclude why they have necessitated chemical treatment.

If you wish to use chemical treatment, you must apply to us to authorise its use. As part of this application, you must include your justification as to why chemical treatment is required. Where your justification is insufficient, your application to use chemical treatment will be refused.

Where chemical treatment has been suitably justified, we will authorise its use and include further discharge limits in your authorisation to control the impact of any heavy metals and / or hazardous substances present in the selected chemical treatment.

Discharges of trade effluent to the water environment:

Where you intend to discharge trade effluent (for example concrete wash waters) from the construction site to the water environment you must apply to SEPA for a separate trade effluent authorisation. This activity will not be covered by your construction run-off licence. Further details on the authorisation requirements for trade effluent discharges are available in our construction regulatory guide.

Current best practice is to discharge trade effluent from construction sites to the to foul sewer with the permission of Scottish Water. Where this is not possible, tankering away is the next best option. Only where you have demonstrated that neither of these options is practicable will SEPA consider an application to discharge trade effluent to the water environment.

Pollution prevention plans:

We believe that you (the operator) are the best person to manage your site in a way that meets the conditions of your authorisation. We also believe that responsible operators should have appropriate plans and procedures in place to manage their sites effectively and prevent pollution of the water environment.

For construction sites, it is best practice to have and implement site-specific plans and procedures to deliver effective construction run-off management and prevent pollution of the water environment. We have produced guidance to help you prepare these pollution prevention plans (see WAT-SG-75).

You are not required to send these plans to us for approval. However, where pollution incidents do occur, we may seek to review your pollution prevention plan as part of our investigation. Absent, inadequate, or badly implemented pollution prevention plans will reflect poorly on you and will be taken into consideration during our assessment of pollution incidents and what enforcement action to take.

Frequently asked questions