Benefits and problems of applying waste water sludge to land

The James Hutton Institute: "Raw sewage cannot be applied directly to the land. Otherwise any pathogens present in the sewage may contaminate fruit, crops and grazing animals. Sewage is therefore treated to remove any pathogens."

Waste water sludge is a useful source of nitrogen, phosphorus and organic matter, and after further processing can be used as a liming material. However, there are limits to what can be applied. For example applications of waste water sludge should not exceed 250 kg nitrogen per hectare per annum particularly within Nitrate Vulnerable Zones...read on.