The Nitrates Directive (91/676/EEC) aims to reduce water pollution caused by nitrogen from agricultural sources and to prevent such pollution in the future. The goal is to improve the quality of inland (surface and ground waters) and coastal waters, which will help to increase compliance with the Water Framework Directive and reduce costs and carbon emissions associated with treatment of water to meet European and national drinking water standards.
The Directive requires Member States to identify waters that are, or could become, polluted by nitrates and to designate as Nitrate Vulnerable Zones (NVZs) all land draining to those waters and contributing to the pollution. The designations are reviewed every four years. For the current assessment, the Environment Agency have commissioned WRc to review and, where necessary, update the methodology used in the previous assessment and support the Agency in developing new boundaries for surface water, groundwater and eutrophic area NVZs in England and Wales.
The delineation of new NVZ boundaries is informed by multiple lines of evidence, which are developed using a combination of approaches including: statistical analysis of monitoring data; forecasting of future water quality; and land use modelling to predict and partition sources of nitrate loading. The results of these analyses are then combined using a weight of evidence approach to identify new areas of land requiring designation, justify the retention of existing designations, and to identify areas for possible de-designation.
As part of this contract, WRc will also conduct a comprehensive quality assurance exercise involving consultation workshops within each region of the Environment Agency in order to obtain the most accurate and up-to-date picture possible of nitrate levels and agricultural influences.
For further information contact Rob Moore at robert.moore@wrcplc.co.uk or telephone +44 (0) 1793 865046.