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Nutrient Neutrality

In March 2022, Natural England confirmed to Vale of White Horse District Council that part of the district falls within the nutrient catchment of the River Lambourn Special Area of Conservation (SAC). The SAC is assessed as being in an unfavourable condition due to phosphorus pollution.

The Council is obliged by law to consider the impacts of granting planning permission on the River Lambourn SAC. Within the identified nutrient catchment, developments which generate and discharge phosphorus must comply with the principles of Nutrient Neutrality.

What is Nutrient Neutrality?

Nutrient Neutrality is an approach which ensures that nutrient pollution is not worsened as a result of development.

Proposals which generate and discharge phosphorus into the River Lamborn SAC nutrient catchment must demonstrate that, as a minimum, the same amount of phosphorus can be removed through mitigation.

Nutrient calculators are used to assess proposals and guide mitigation requirements.

What is nutrient mitigation?

Nutrient mitigation reduces the amount of phosphorus entering into the nutrient catchment. Nutrient mitigation could be:

  • Taking land out of agricultural production and creating habitats
  • Retrofitting existing foul water infrastructure with newer, more-efficient systems
  • Providing high-quality SUDS which prevent nutrients from leaving development sites

Currently, mitigation must be provided by developers on a case-by-case basis, and address the specific nutrient implications of their development.

What developments are within scope of Nutrient Neutrality?

Development which results in new overnight accommodation, within the nutrient catchment of the SAC, is likely to contribute to phosphorus levels. Overnight accommodation generates wastewater, which contains phosphorus. Natural England has confirmed that the following forms of development are within the scope of Nutrient Neutrality:

  • New homes
  • Barn/outbuilding conversions (creating a separate planning unit)
  • Student accommodation
  • Care homes
  • Hotels
  • Guest houses
  • Bed and breakfasts
  • Self-catering holiday chalets
  • Static caravan sites
  • Other tourism attractions and tourism accommodation
  • Permitted development which gives rise to new overnight accommodation (e.g. Part 3, Class Q of the GPDO)

The above list is not exhaustive. Other developments that generate overnight stays within the catchment (e.g. conference facilities), or certain industrial/agricultural proposals may also have nutrient implications which are within the scope of Nutrient Neutrality.

It is important to note that householder extensions providing new bedrooms, or ‘granny annex’ developments which do not result in creation of a separate planning unit, do not fall within the scope of Natural England’s advice.

Is there any exemption to Nutrient Neutrality?

Developments which propose a package treatment plant, with a discharge rate of no more than 2 cubic metres per day, may benefit from a specific ‘insignificant phosphorus discharge to ground’ exemption from detailed assessment and mitigation, subject to certain criteria being met.

This matter requires detailed scrutiny of proposals. Applicants wanting to see whether their proposal will benefit from the exemption are advised to seek pre-application advice.

At what stage does Nutrient Neutrality apply?

A recent judgement issued by the High Court has confirmed that Nutrient Neutrality can apply to all stages of development management approval.

Where there is an extant permission, granted before Nutrient Neutrality advice was in effect, but where some additional approval is required before works can commence, the development needs to be scrutinised for compliance with Nutrient Neutrality. This requirement applies regardless as to whether the additional approval has nutrient implications or not (e.g., principle of development or foul sewerage details).

This is because approval of the additional detail could be the “implementing decision”, which allows development to commence. Without all relevant approvals being issued, development cannot commence lawfully.

Some examples are provided below to provide clarity.

Example 1:
Planning permission was granted for a single new dwelling within the nutrient catchment prior to Nutrient Neutrality being in effect. Nutrient Neutrality was not considered during the assessment of the original planning application. This permission included a planning condition requiring the developer to agree the materials of the new dwelling with the Council, prior to commencement. The developer submits details to discharge the requirements of the condition.

In this example, the whole development would need to demonstrate compliance with Nutrient Neutrality, even though the submitted detail relates only to external materials. The Council cannot lawfully issue an implementing decision without being satisfied that the development would not worsen nutrient pollution within the identified nutrient catchment.

Example 2:
Planning permission was granted for three new dwellings within the nutrient catchment prior to Nutrient Neutrality being in effect. Nutrient Neutrality was not considered during the assessment of the original planning application. The developer now submits an application to vary the approved plans condition applied to that permission (also known as a ‘Section 73’ application).

In this example, the whole development would need to demonstrate compliance with Nutrient Neutrality. When the Council approves a ‘Section 73’ application, a new and separate planning permission is being issued. This application would need to demonstrate compliance with Nutrient Neutrality for the Council to lawfully issue a decision, regardless of the fact that there is a similar extant permission.

Example 3:
Planning permission was granted for a barn conversion, creating a new residential planning unit, within the nutrient catchment after Nutrient Neutrality being in effect. Nutrient Neutrality was demonstrated during the application process and the Council deemed the proposed nutrient mitigation measures to be appropriate.  This permission included a planning condition requiring the developer to agree tree protection details with the Council, prior to commencement. The developer submits details to discharge the requirements of the condition.

In this example, the development has already demonstrated compliance with Nutrient Neutrality. This does not need to be demonstrated again, unless there are material changes which would impact the previous Nutrient Neutrality assessment. The submitted tree protection details can be considered in the normal way.

Nutrient Neutrality applies to my proposal. What do I need to support my planning application with?

The onus is on the applicant to demonstrate that their proposal complies with Nutrient Neutrality. Applicants will likely need to engage with specialist consultants and provide technical information to demonstrate compliance.

Nutrient Neutrality tools and guidance can be downloaded using the links below. These resources can assess the nutrient implications of a proposed development and guide the provision of appropriate mitigation. Mitigation proposals will need to be devised in conjunction with specialist consultant help.

Applicants proposing development and mitigation within the nutrient catchment are encouraged to utilise pre-application advice to minimise delays to the application assessment process.