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Nutrient neutrality and its impact on development

Caroline Waller, a partner in our Planning team, discusses the topic of the current phosphates and nitrates issue and looks at the impact that nutrient neutrality is having on development.

There is something in the water. The widely publicised Environmental Audit Committee report “Water quality in rivers” concluded that there is a ‘Chemical cocktail’ of sewage, slurry and plastic polluting English rivers puts public health and nature at risk. Clearly something needs to be done, particularly to tighten regulation on water authorities and to address agricultural run-off.

In the meantime, water pollution is having a significant adverse impact on the ability of this country to meet its housing needs in certain areas. This is because following the Dutch Nitrogen case in 2018, Natural England has designated certain European Protected sites as being in unfavourable conservation status due to the nutrient loading in those sites. Any development which may increase those nutrient levels cannot be permitted.

So, why is this affecting housing supply? It is generally accepted that wastewater from dwellings would result in an increase in nutrients being discharged to water courses as wastewater treatment works do not remove all of the nutrients from foul water drainage before the treated water is discharged into the environment.

Therefore, planning permission cannot be granted for any new development which drains to the catchment area of the protected site, without the Local Planning Authority (LPA) undertaking an appropriate assessment. This must then conclude that the development on its own, or in combination with all other development, would not have a significant effect on the integrity of the protected site.

This is a relatively complex issue. However, in short, the development must demonstrate that it is “nutrient neutral”: which means that the nutrients (nitrogen and/or phosphorus) from all surface water runoff and wastewater generated by the development, will less than or equal to the nutrients generated by the existing land use.

When Natural England designates a protected site as being in unfavourable conservation status, the above effect is instantaneous; there is no advance warning. Your planning application may have a resolution to grant with the decision notice being due any day but as from the date of Natural England’s advice to the authority, planning permission will not be issued without an appropriate assessment being carried out to confirm nutrient neutrality.

This happened in Somerset in August last year in respect of the Levels RAMSAR site and has now happened in Cornwall in respect of the River Camel SAC. The Stour Valley has also now been designated. The Solent and River Avon catchment areas were designated some time ago.

According to the Home Builders Federation, the issue currently affects 20 LPAs and it is estimated that 30-40,000 homes are currently delayed.

However, the nutrient issue isn’t just affecting new applications for planning permission. Some LPAs have placed an embargo on the discharge of any pre-commencement conditions unless and until the underlying development has been found to be nutrient neutral. Without the ability to go back and plan mitigation into the already constructed parts of the development, it is very difficult to demonstrate nutrient neutrality without providing significant off-site mitigation schemes. Such schemes are usually expensive and, in this case, do not present a feasible option.

This is proving hugely disruptive to a huge number of developers and we are working hard to find solutions.

So what is the solution? As explained above, in order to obtain a decision notice from the LPA, the developer needs to demonstrate nutrient neutrality. This needs to be confirmed through a Habitats Regulation Assessment (HRA) which is undertaken by the LPA as a competent authority. Competent authorities must consult with Natural England and will usually not sign off an assessment unless Natural England agrees.

Each development will be subject to this assessment process – with the LPA needing to carry out an appropriate assessment and consult with Natural England for every planning application no matter how small. For very small developments, it might be possible to deal with the issue through use of a package treatment plant (although that has its own challenges). For a larger development, off-site mitigation strategies are generally required, which often involves taking agricultural land out of production (which creates further problems for a country seeking to improve food security).

This therefore means it is easier to achieve mitigation where development is on land that is currently being farmed. It is harder to show nutrient neutrality on brownfield sites. While this may sound straightforward, the supply of land is finite and to mitigate development, it is usually necessary to fallow a relatively large area of land. This then pushes up agricultural land prices and pushes up the cost of mitigation measures.

Some schemes which have been promoted by LPAs are expected to function on auction arrangement – whereby “credits” are sold to the highest bidder. This prices smaller developers out of the market. Also, more complex developments with smaller margins (such as brownfield development) will also find it harder to compete in such scenarios.

Even if an independent mitigation proposal is found, it still needs to go through HRA process with Natural England involvement

However, the main problem with nutrient neutrality is the delay. There is a real resourcing issue. Overnight, a LPA will have gone from having to consider a small number of assessments a year, to suddenly having to undertake a HRA for every single planning application. The LPAs, who are already over-stretched and under-funded, simply do not have the manpower or, in some cases, the expertise, to deal with this unexpected significant increase in work.

From a site specific level and practical point of view, in areas which are affected by this issue ensure that you factor in the potential for a significant delay into your contracts and development programme. Engage directly with Natural England in terms of mitigation measures to check they will be acceptable, and unfortunately be prepared for significant additional costs.

Finally, if you are looking at acquiring a site or getting involved in a development, check whether nutrient loading is likely to be an issue, and check whether the site is in the catchment area of a protected site with declining conservation status. Such sites are likely to be the next to be designated.

For further information please do get in touch with our expert nationwide Planning team.


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