Groundwater Protection Requirements

4.1 Introduction

This Part of the NS-GRA explains how the groundwater protection requirements apply to a radioactive waste disposal facility and what you need to do to meet them.

As specified in requirement R14: Protecting groundwater, you must ensure that your radioactive waste disposal facility does not cause pollution of groundwater at any stage both during and after the period of RSR.

The obligations for protection of groundwater come through the Water Environment (Controlled Activities) (Scotland) Regulations 2011 (CAR). CAR requires compliance with the Water Framework Directive or WFD (Directive 2000/60/EC), and the Groundwater Daughter Directive or GWDD (Directive 2006/118/EC).

4.2 Applying CAR to Radioactive Waste Disposal Facilities

CAR applies to a range of “controlled activities” which may affect the water environment. The activity of operating a near-surface radioactive waste disposal facility meets the criteria to be considered a controlled activity and so must be authorised under CAR. You will not need a separate CAR authorisation for a radioactive substances activity authorised under EASR in accordance with Schedule 8 as the latter is a “relevant authorisation” for the purposes of CAR.

However, you may need separate authorisation under CAR for activities you undertake during the investigation and construction phases of your facility. CAR allows for proportionate regulation of some low-risk activities through a system of “general binding rules” (GBRs), some of which may be relevant to the investigation and construction phases.

CAR specifies what SEPA must consider when assessing any application for a permit to operate a radioactive waste disposal facility. For radioactive waste disposal facilities, we are primarily concerned with ensuring that you comply with the requirements of Article 6 of the Groundwater Directive, to prevent and limit inputs of pollutants into groundwater. These requirements may be eased by certain exemptions.

4.3 Scope of This Guidance Regarding CAR

This guidance only deals with the protection of groundwater from your disposal facility, as built and operated in accordance with an EASR permit for radioactive substances activities. This guidance does not cover impacts on groundwater associated with the construction of your disposal facility. You will need to consider these other risks to groundwater, for example for dewatering operations, and ensure you are appropriately authorised. If you are not sure what activities might require to be separately authorised under CAR, please get in touch with us for advice.

4.4 Defining Groundwater

The “Water Environment and Water Services (Scotland) Act 2003” at section 3(4) defines groundwater as:

“water which is below the surface of the ground in the saturation zone and in direct contact with the ground or subsoil.”

The definition above potentially covers nearly all water beneath the surface of the ground. However, we make a distinction between groundwater that is used as a resource or has the potential to be used as a resource, and groundwater that is not a potential resource:

1. The environmental standards for inputs into groundwater of hazardous substances should not be applied to:
   1. groundwater that is below mean high-water springs or
   2. is greater than 400m below ground level
2. Provided these waters have a level of natural electrical conductivity of greater than or equal to the Scottish Drinking Water Standard as set out in The Water Intended For Human Consumption (Private Supplies) (Scotland) Regulations 2017 and The Public Water Supplies (Scotland) Regulations 2014 and there is no significant pathway to surface ecosystems.

Therefore, requirement R14 does not apply to groundwater beneath the sea or at depths greater than 400m below ground level, if it is saline enough to exceed the relevant level of electrical conductivity.

4.5 Demonstrating Compliance with Requirement R14

You should use your ESC to demonstrate that your radioactive waste disposal facility will comply with requirement R14. You should integrate your assessment of groundwater impacts into the relevant environmental safety assessments that form part of your ESC.

You must demonstrate that your radioactive waste disposal facility is:

• designed and constructed with a suitable barrier system to prevent all direct discharges of pollutants to groundwater; and
• operated and closed so that any indirect inputs of pollutants to groundwater comply with the standards described below.

You do not need to undertake a specific groundwater assessment for radioactive substances, but you should ensure that the relevant assessments that you undertake for other purposes address the protecting groundwater requirement. The relevant assessments include your:

• radiological assessment relating to the protection of people from migration of radionuclides from your disposal facility both during and after RSR
• radiological assessment relating to the protection of wild animals and plants
• assessment of impacts of non-radioactive hazardous and non-hazardous substances.

For your radiological assessments, if you can show compliance with the radiological standards in this guidance for the protection of people from a source or sites [standards 2 and 3], and of plants and animals [requirement R13] you will also have demonstrated that the groundwater is protected. This is in accordance with our “Environmental Standards for Inputs of Radioactive Substances into Groundwater Consultation document October 2024”.

For your assessment of the non-radiological hazards associated with the radioactive waste (requirement R15), you will need to demonstrate that you have met the appropriate standards for non-radioactive hazardous and non-hazardous substances entering groundwater. The standards that you should be aiming to achieve are set out in SEPA’s position statement “Assigning Groundwater Assessment Criteria for Pollutant Inputs (WAT-PS-10-01)”.

If you are unable to show full compliance with the standards set out in WAT-PS-10-01 for the non-radiological properties of the radioactive waste, you may be able to provide suitable arguments to allow SEPA to consider if any of the Groundwater Directive Article 6 exemptions should apply.