Anything but Neutral – Nutrient Budgets & Wyatt v Fareham Borough Council

Roy Pinnock and Grace Pinault assess the implications of a recent decision on nutrient neutrality and planning.

Nitrogen neutrality issues have been a long time coming but have taken policy makers, authorities and developers by surprise. In R (Wyatt) v Fareham BC & Natural England [2022] EWCA Civ 983 [2022] EWCA Civ 983 the Court of Appeal rejected objectors’ appeal against the High Court’s decision to dismiss an application for judicial review of Fareham Borough Council’s decision to grant outline planning permission relying on guidance issued by Natural England (NE).

The case is helpful in understanding the Court’s approach to scientific modelling, the role of professional judgment and the future application of NE’s nutrient advice.

Back to Basics – reasons and doubt

‘Appropriate Assessment’ is intended to allow authorities to rule out any adverse effects on the integrity of designated areas “without lacunae and [with] complete, precise and definitive findings and conclusions capable of removing all reasonable scientific doubt“. That precautionary approach means using the ‘best scientific knowledge in the field’ – up to date analysis, not just professional assertion.  The Courts recognise that this nonetheless allows for reaching a subjective view.

Natural England’s guidance at the time of Fareham’s decision (Issued under section 4 of the Natural Environment and Rural Communities Act 2006) advocated the calculation of a “nutrient budget” for proposals which could affect the Solent SPA and refusal where mitigation cannot be achieved to avoid any residual increase in nutrient levels. The Guidance includes a methodology, along with suggested coefficients, to measure nutrient outputs from proposed developments with elements of overnight accommodation. It applied a national average occupancy rate and a 20% buffer on top.

Chase Perfection, Attain Excellence

The Court of Appeal rejected the following grounds of challenge:

1. Applying a 2.4 occupants/dwelling (national average) figure for the budget calculation was not the best science available because local occupancy figures were available which could be applied to the specific dwellings’ above-average size: The 2.4 figure was one part of the overall methodology – NE’s witness evidence explained the rationale for using it and how it slotted into an overall precautionary approach.
2. The use of average figures for existing land uses to inform baseline nitrogen flows were unlawful: There is a difference between using averages in ‘programmatic’ legislation (allowing various things, as in the Dutch Nitrogen Coöperatie Mobilisation for the Environment UA, Vereniging Leefmilieu v College van Gedeputeerde Staten van Limburg (Case C-293/17) [2019] Env LR 27] case) versus guidance to be considered when being applied to individual schemes.
3. The 20% buffer lacked any scientific basis: The Court of Appeal instead held that professional judgment did not require an arithmetical calculation in every case – applying the Wednesbury standard (legal perversity) was enough and the overall approach was (it transpired in witness evidence from NE) the product of reasoned professional judgement based on consideration which viewed in the round was sufficiently precautionary.

The authority consulted NE twice on the nitrogen budget and NE raised no concerns on the methodology or application of its advice. The Court of Appeal held that the Council’s decision to grant planning permission was legally sound in part because of this consultation.

So what?

The judgment is helpful in reinforcing several points about the approach to nitrogen impact assessment, habitats assessment and the precautionary approach more generally which should help everyone in the planning process:

1. NE’s views matter. Competent authorities are entitled to give significant attention and weight to the advice of an expert national agency which relevant expertise in the sphere of nature conservation. NE’s blessing of the authority’s approach was a significant point.
2. Guidance is meant to be applied sensibly, having regard to specific circumstances.
   • How those are taken into account is a matter for professional judgement subject to the Wednesbury standard. Adopting ‘bespoke calculations’ fine, where justified (and endorsed by the Guidance) (paragraph 20 of the Judgment).
   • The flip side of that is that (and point I. above) is authorities (and therefore applicants) will need to give “compelling reasons […] to depart from Natural England’s position (paragraph 61).  
3. ‘Best science’ does not require every input to be ‘best’, just the methodology as a whole to work in a way that is scientifically complete and professionally justified on a Wednesbury basis. The Court must take a “holistic” view on the question whether the assessment methodology as a whole represents “best scientific knowledge” (paragraph 59).  Disputes between experts on specific inputs or assumptions should therefore generally not be enough to overturn the applecart.
4. The ‘reasonable worst case scenario’ is a decent way, but not the only way, to address reasonable doubt. It does not always have to be assessed where there is doubt.
5. A ‘Wednesbury Plus’ standard is not needed– the legal perversity principle had to be “deployed with suitable rigour in the legislative context”. That meant establishing whether, in all the circumstances, the council had reached a reasonable and lawful conclusion, as a matter of its own exercise of evaluative judgment, in ascertaining whether the high threshold set by regulation 63(5) had been surmounted. The Courts will apply “an appropriately intense standard of scrutiny, consistent with the proper application of Wednesbury principles” rather than raising the Wednesbury bar.

The Judgment therefore leaves open room for dialogue on issues which may be capable of being better resolved for specific areas or schemes, in terms of occupancy rates, overall budgets and buffer levels.

A Fix

The Government’s ‘nutrient fix’ proposals announced on 20 July 2022 offer a route out in the medium term:

• A new legal duty on water companies in England to upgrade wastewater treatment works by 2030 in ‘nutrient neutrality’ areas to the highest achievable technological levels.
• A new Nutrient Mitigation Scheme established by Natural England, helping wildlife and boosting access to nature by investing in projects like new and expanded wetlands and woodlands. This will allow local planning authorities to grant planning permission for new developments in areas with nutrient pollution issues, providing for the development of sustainable new homes and ensuring building can go ahead. Defra and DLUHC will provide funding to pump prime the scheme.

This is a big step forward but it remains to be seen how the costs of delivering Nutrient Mitigation Schemes will flow through to developers (and how they should be priced in to land value/ Local Plan expectations) given that the land for mitigation is already beginning to attract significant landowner value expectation.

Roy Pinnock is a partner in the Planning and Public Law team and Grace Pinault is a trainee solicitor at Dentons. This article first appeared on the firm's Planning Law Blog.