Regulatory Decision 073: Land contamination small scale remediation

This Regulatory Decision (RD) is valid until 30 November 2026 by which time it will be reviewed. You should check back at that time to ensure the RD is still valid.

NRW can withdraw or amend this RD before the review date if we consider it necessary. This includes where the activities that this RD relates to have not changed.

If you comply with the requirements below, we will allow small scale remediation of land in specified circumstances without the need for an environmental permit.

If you cannot comply with the conditions in this RD, you need to apply for an environmental permit.

Regulatory Decision

This RD applies when you carry out time limited, small scale:

  • remediation of soil and groundwater for pollution incidents or historic land contamination
  • site-specific remediation trials to find out if a technique will be effective

A site-specific remediation trial means using one or more of the established techniques given in this RD to see if the type of treatment will work on a particular waste or site.

Small scale means the specified volumes given in this RD.

 

Conditions you must comply with 

You must:

Use established remediation techniques

You must only use the following remediation techniques, on their own or in combination, for in situ or ex situ treatment of soil and groundwater:

  • air sparging
  • bioremediation such as windrows, biopiles and in-vessel reactors
  • biosparging
  • bioventing
  • chemical treatment such as oxidation and dehalogenation
  • treatment of groundwater, using for example, chemical and biological treatment, air stripping, filtration, or carbon adsorption
  • soil vapour extraction including dual phase
  • soil flushing including steam injection
  • soil washing
  • solidification and stabilisation
  • thermal treatment such as desorption and steam injection
  • treatment plant for sorting and separation
  • treatment plant for blending, mixing, bulking, screening, shredding, particle size reduction and or particle separation to facilitate remedial action

You must:

  • if using chemicals, only use them in a concentration and volume necessary to achieve the objectives of any treatment
  • meet the requirements for emissions, noise and vibration, and odour and follow the principles given in the deployment form guidance
  • prevent hazardous substances from entering groundwater

Storing waste

You must:

  • store the contaminated soil or groundwater in a secure place
  • store all liquid waste in containers and use secondary containment

Secondary containment must have:

  • an impermeable lining
  • a capacity of 110% or more of the original container’s storage capacity
  • a capacity of 110% or more of the largest container’s storage capacity for 2 or more containers
  • a capacity of 25% of the aggregated storage capacity of all containers

You must take reasonable measures to always maintain these.

Secure place means all reasonable precautions are taken to make sure the waste cannot escape and that unauthorised people are unable to gain access to the waste.

Secondary containment means using a bund or other system to prevent any waste that leaks from a primary container escaping from the place where it is stored.

Produce a method statement

You must produce and follow a method statement. It must include:

  • background details:
    - your contact details and the competent person, if different
    - a site address, grid reference and a site plan that shows the site boundary and physical extent of the remediation or trial
    - details of why remediation or trials are required
    - details if it is soil or groundwater you are treating or a combination of the two
    - the established technique or techniques you are using
    - expected duration of the activity and when it will start
  • how you will temporarily and securely store treated waste and products used
  • details of the regulatory controls in place if you are going to reuse any treated material
  • details of all process plant, equipment and any substances used for the remediation
  • evidence that you have assessed the risks to the site and surroundings – you can use, for example, the conceptual site model you’ve developed
  • for in situ groundwater treatment, a calculation of how much will be treated based on hydrogeological data
  • the mitigation measures you have in place for emissions, noise and vibration, and odour
  • the expected outcome
  • a contingency plan if the remediation or trial does not work as expected

To use a remediation technique not listed in this Regulatory Decision

If you want to use a remediation technique not listed in this Regulatory Decision which is a waste operation or a groundwater activity (or both), you must follow these requirements.

For a waste operation you must either:

  • use and comply with our guidance on carrying out research or trials with waste at sites without an environmental permit
  • apply for a bespoke environmental permit for a waste operation

For a groundwater activity you must either:

Complete the activity and keep records

You must:

  • complete the activity as soon as possible
  • only use this Regulatory Decision once in a 3-year period for an individual site or remediation project as shown on your site plan
  • keep records for 2 years from the date of the last use of the Regulatory Decision to show that you have complied with this Regulatory Decision and make these records available to us on request

You must keep records of:

  • method statement
  • volumes treated
  • verification of remedial objectives
  • any pollution incidents and how these were dealt with
  • any unexpected contamination
  • any correspondence with us

Restrictions under this Regulatory Decision

You must not:

  • treat more than 1,000 cubic metres of soil and or groundwater in total
  • re-deposit treated soils
  • discharge the treated groundwater back to the ground, groundwater or surface water without a groundwater or water discharge activity permit
  • import or treat imported waste
  • store waste for more than 12 months

Things to note

This Regulatory Decision relates to an activity that we consider potentially suitable to be an exemption under the Environmental Permitting (England and Wales) Regulations 2016. A groundwater activity is defined in paragraph 3 of Schedule 22 of the Environmental Permitting (England and Wales) Regulations 2016.

Deal with treated soils

To deal with treated soils you can:

The 2 waste exemptions most applicable to land remediation activities are: 

Any exemptions must be registered with Natural Resources Wales.

Deal with treated groundwater

To deal with treated groundwater you can:

  • apply for an environmental permit for a groundwater activity to discharge the treated groundwater back to the ground
  • get permission from your local sewerage undertaker to discharge the treated groundwater to a foul sewer
  • only dispose the treated groundwater to an authorised facility that has the correct regulatory controls in place to accept the waste
  • apply for an environmental permit for a water discharge activity to discharge the treated groundwater to a surface water

Apply for a permit

You must apply for an environmental permit if you want to do:

  • more trials or remediation at the site
  • treatment for recovery or disposal above the limits in this Regulatory Decision
  • a groundwater activity above the limits in this Regulatory Decision, and no other exclusion or exemption applies

For details of permits and permissions see the section on ‘types of regulatory controls’ in the guidance LCRM.

When you must check back

We intend to review this Regulatory Decision by 30 November 2026.

We can withdraw or amend this regulatory position before the review date if they consider it necessary. This includes where the activity that this Regulatory Decision relates to has not changed.

You will need to check back from time to time, including at and before the review date, to see if this Regulatory Decision still applies.

This Regulatory Decision remains in force until it is removed or is otherwise identified as having been withdrawn.

If you cannot comply with this Regulatory Decision

If you operate under this Regulatory Decision but can no longer comply with it, you must stop the activity to which this Regulatory Decision relates and must tell the us immediately.

Enforcement

This RD does not change your legal requirement to have an environmental permit for small scale remediation of land.

However, NRW will not normally take enforcement action if you do not comply with the need for an environmental permit if you meet the requirements in this RD.

In addition your activity must not cause (or be likely to cause) pollution of the environment or harm to human health, and must not:

  • cause a risk to water, air, soil, plants or animals
  • cause a nuisance through noise or odours
  • adversely affect the countryside or places of special interest

 

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