Nitrate vulnerable zones: How do you challenge a designation?

Summary

In the recent case of John M Clapp v The Secretary of State for Environment, Food and Rural Affairs, the Department for Environment, Food and Rural Affairs (Defra) was found to have wrongly designated land as falling within a nitrate vulnerable zone (NVZ), and therefore the restrictions placed on agricultural activities should not have been imposed. NVZs make up approximately 55% of land in England, and this case is of particular interest to occupiers of NVZs who are taking actions to reduce nitrate leaching on their property and may also be able to challenge their NVZ designation and restrictions.

Background

A NVZ is a designated area of land that drains into ground or surface waters that are polluted or potentially polluted by nitrates. Water is polluted if it contains a concentration of nitrates greater than 50 mg/l. Occupiers of NVZs must comply with restrictions on the use of nitrogen fertilisers and the storage of manure pursuant to the Nitrate Pollution Prevention Regulations 2015 (the Regulations). Defra reviews NVZs every four years to account for changes in nitrate concentrations.

The Regulations set out various requirements that must be followed by occupiers of NVZs, with the aim of reducing nitrate leaching, including:

• Complying with annual limits on the amount of nitrogen from organic manure and livestock manure that may be applied or spread in a holding in a NVZ.
• Planning in advance how much nitrogen fertiliser will be spread and ensuring that the use of nitrogen fertiliser does not exceed limits.
• Maintaining a risk map that identifies the fields, water sources and areas that have a low risk of run-off.
• Complying with various restrictions on how and where nitrogen fertiliser can be used and the prohibitions on spreading nitrogen fertiliser during specified seasons.
• Storing organic manure in compliance with the Regulations.
• Keeping a number of records.

Failure to comply with the Regulations is an offence for which the maximum penalty is an unlimited fine. Alternatively, the Environment Agency (EA) may impose a fixed monetary penalty, variable monetary penalty, restoration notice, compliance notice or stop notice, or may accept an enforcement undertaking. A director, manager, secretary or other similar officer of a company convicted of an offence may also be personally liable.

An appeal can be made within 28 days of a designation if the land does not drain into water that has been identified as polluted or drains into water that should not be identified as polluted.

Facts of the case

The case involved a farmer, Mr Clapp, who runs a mixed arable and livestock business at Tiverton, Devon on the edge of a NVZ. Mr Clapp had taken major steps to reduce nitrate leaching over the past 16 years. When Defra reviewed the NVZ designation, however, it deemed the nitrate concentration within the groundwater met the threshold used to define polluted water and the designation was retained. Mr Clapp appealed against the designation, arguing that it was wrong to continue to identify the water into which the land drained as polluted.

Basis of challenge

Mr Clapp challenged the evidential basis relied upon by the EA on behalf of Defra as justification for the NVZ designation:

• It was contended that the designation relied on questionable datasets instead of the Defra agricultural census data, with possible misclassifications. 
• 22,000 samples were taken annually to determine NVZ areas in England according to a NVZ review document from 2023. In contrast, only 20 water tests were done in 2025 to cover the whole NVZ designation area of more than 700 sq km in the appeal case. Only six of the 20 tests taken exceeded the nitrate threshold.
• The nitrate must be measured at representative locations in order to identify water that is affected by pollution. Only three of the sampling points were close to the farmer’s property. Only one had a nitrate concentration above the nitrate threshold.
• The designation did not attempt to exclude monitoring points affected by urban runoff or sewage effluent, potentially skewing results against agriculture.
• The groundwater testing was undertaken in November to March when nitrate leaching risk is highest, meaning the data could represent a worst-case scenario rather than year-round conditions.
• The methodology for designating NVZs for groundwaters prepared by the EA was not followed. Instead, the approach taken was to look at changes over the last three cycles of NVZ designation review since 2008. Changes of less than 1% in the water quality sampling data were identified, so it was concluded that there had not been significant changes to warrant de-designation. No updated land use data was presented to the Tribunal and it was unclear to the Tribunal why this critical element of the previously accepted methodology was not available.

Tribunal decision

The Tribunal noted “serious shortcomings” in the approach taken by the EA which informed Defra’s NVZ designation which revealed “significant cause for concern in the soundness of the conclusion reached”. Therefore, the Tribunal found that it was wrong for the EA to conclude that the water was affected by pollution on the evidential basis it relied upon on behalf of Defra in this case.

How we can support you

It is important for occupiers to ensure full compliance with the Regulations on NVZ designated land, not only to prevent enforcement action, but also to protect the environment. If you have followed these measures however, and consider that land may have been wrongly designated, we would be happy to advise you.

Mills & Reeve offers a full-service team specialising in a variety of agricultural matters. Our environmental and regulatory lawyers can support you with understanding a NVZ designation, compliance with the Regulations, and making an appeal to challenge a designation or enforcement action. Our real estate and corporate teams regularly advise farmers, agricultural contractors and short-term occupiers, and landlords. Our planning specialists also provide wider support to the agricultural sector and can advise on farming intensification and on new planning applications for farming facilities, negotiating section 106 agreements and responding to compulsory purchase orders.

For further information on how NVZs may affect your business and property, please contact Rob Biddlecombe, Callum Ross, or Alysha Patel.

Our content explained