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Guidance for cleaner waters: Water discharge management on construction sites (Scotland)

In the past, water discharge from construction sites was regulated by General Binding Rule 10 of The Water Environment (Controlled Activities) Regulations or “CAR”. However, in January 2018, CAR was amended (and continues to be). Now, any construction project that meets the following thresholds will need to apply for a permit to discharge water from the construction site:

  • A construction site of 4 hectares or more

  • A length 5 kilometres or more

  • The development contains any area of more than 1 hectare or any length of more than 500 meters on ground with a slope steeper than 25 degrees

What this means for construction projects

  • A permit is now required before any construction work, including preparatory ground works can begin. Projects can’t start without obtaining this permit, and the application process has a four-month statutory response period.

  • A named person must take responsibility for ensuring compliance with the permit.

  • SEPA (Scottish Environment Protection Agency) still talks about visible discolouration, but they have also added a Total Suspended Solids threshold, which is measured in mg/L rather than using NTU (Nephelometric Turbidity Units), making it harder to identify on-site without the right equipment and expertise. There is also a mechanism to set other thresholds for aluminium levels for example.

  • Construction work cannot commence until the responsible person has prepared a Pollution Prevention Plan (PPP) and it has been agreed with SEPA in writing.

  • Multiple PPPs will be needed to cover phased construction activities.

  • Any changes to the PPP will need to be agreed in writing with SEPA before being implemented (unless in an emergency).

  • The responsible person must report any breach of thresholds within 24hrs.

  • The responsible person is required to submit a report to SEPA within 2 weeks.

Any project that does not meet these thresholds are still obliged to meet GBR 10. Rather than having TSS or NTU thresholds GBR 10 requires the project to not visibly discolour the water which is why Visible Discolouration is so important

Pollution Protection Plan requirements

The detailed PPP does not need to be submitted with the permit application, however, it does need to be agreed upon with SEPA in writing prior to works commencing. Once agreed, the PPP will be tied to the permit. However, SEPA do not have a statutory response period for the PPP and may reject it if they do not feel it’s adequate, potentially causing significant delays to the start of the project.

The PPP must include the following information:

  • Details of the project

  • Points of contact

  • Pollution risks such as sediment and chemicals

  • Location of discharge points

  • Details of drainage systems – whether they are appropriate for the anticipated volume/flow of water and the type of pollutant.

  • Contingency plans if something goes wrong

  • How will the project ensure the effectiveness of the plan

  • The person responsible for implementing the plan

Naturally Compliant has a strong track record of supporting clients with their Surface water management, Sediment management, and pollution prevention plans. For more information on how we can help, please contact Simon Knott at,


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