The new rules established by the Nitrate Pollution Prevention Regulations 2008 will only be enforced in relation to agricultural holdings, and enterprises claiming subsidy under the single payment scheme, if they are located in a Nitrate Vulnerable Zone (NVZ). This means that if horses (including foals) are kept on these holdings or enterprises, the manure produced by the animals is subject to the NVZ rules. If, however, the horses are kept on holdings/enterprises which are not agricultural (e.g. livery yards), then the owners do not need to comply with the rules.