Reduce the risk of spreading infection between ponds (or other farming units) by restricting movements of people, equipment and other possible agents.
This applies both to visitors to a farm, as well as farm staff. If staff are only involved in certain aspects of the farming operation, their movements should be restricted to only those areas they need to visit for their duties. If staff must move between different units of a farm, the use of facilities to wash hands and footwear between areas can be used to reduce the risk of transfer of disease.