Livestock production is inherently ‘leaky’ with materials moving from the farming system into waters and the atmosphere as part of the biogeochemical cycling processes that occur in all ecosystems. Increasingly, there are national and international legislative pressures to minimise fluxes of environmentally active materials into waters and the atmosphere. Public opinion is also demanding that the husbandry and management of livestock production is adjusted to take account of the short and the long term impacts on environmental quality. Although livestock farms may be responsible for point source effects these have diminished over recent years and the greater concern is with diffuse pollution effects.