The Nitrate Pollution Prevention Regulations 2008 allowed for appeals to be made against the decision to designate certain areas of England as NVZs if there was evidence to demonstrate that:
• the land does not drain into water identified as nitrate-polluted, and/or
• the water to which the land drains should not have been identified as polluted.
http://www.defra.gov.uk/environment/quality/water/waterquality/diffuse/nitrate/nvz2008.htm