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Nitrates - Nitrate Vulnerable Zones in England

Where are the Nitrate Vulnerable Zones in England?

A total of 55% of England was designated as a Nitrate Vulnerable Zone (NVZ) in October 2002 (this includes the 8% originally designated in 1996).

Maps of these current NVZs are available. An interactive, mapping service can be used to determine exactly which fields are located in the new NVZs and why an area of land has been included within a NVZ.

Farmers located in the current NVZs have been required to apply Action Programme measures to reduce nitrate leaching since 19 December 2002.

How were the NVZs identified?

The Nitrates Directive requires the identification of nitrate polluted waters using the following specific criteria:

  • Surface freshwaters which contain or could contain, if preventative action is not taken, nitrate concentrations greater than 50mg/l.
  • Groundwaters which contain or could contain, if preventative action is not taken, nitrate concentrations greater than 50mg/l.
  • Natural freshwater lakes, or other freshwater bodies, estuaries, coastal waters and marine waters which are eutrophic or may become so in the near future if protective action is not taken.

Monitoring data collected by the Environment Agency from a network of monitoring points and boreholes is assessed against the above criteria for the identification of nitrate polluted waters. More information about how the Environment Agency monitors water quality is available at the Environment Agency web site.

The Nitrates Directive also requires all known areas of land draining into nitrate polluted waters to be identified for designation as Nitrate Vulnerable Zones (NVZs). Therefore, if an area of land drains into one or more of the above categories of polluted water, it will be located within a NVZ.

A detailed description of how the monitoring data was used in 2002 to identify the polluted waters, and how the areas of land draining into the polluted waters were identified, is contained within the document. Description of the methodology applied by the Secretary of State in identifying additional NVZs in England 2002.

Review of the NVZs

A recent review of the current NVZs indicates that we need to increase coverage to about 70% of England.  Regional maps of the revised NVZs proposed for designation in 2008 are available.

The methodology for identifying NVZs was updated during the recent review in light of developments in scientific understanding.  A Steering Group, which included stakeholders and independent technical experts, was established to help develop and refine this revised NVZ methodology [delete link] which was used to identify the NVZs proposed for designation in 2008.

Page last modified: 21 July 2008
Page published: 27 June 2002

Department for Environment, Food and Rural Affairs