Proceedings

Landspreading of sewage sludge remains the most economical and practical means for its disposal,
with some countries, such as Ireland, disposing up to 80% to land. Its nitrogen, phosphorus and metal
content make it an effective fertiliser replacement. However, there are potentially serious issues
associated with its use in agriculture. These range from impacts on the environment through surface
losses of nutrients, metals, pharmaceuticals and personal care products (PPCPs), and emerging
contaminants, as well as build-up of contaminants in the soil and transfer to the human food chain.
This paper details the main findings of an Irish Environmental Protection Agency (EPA)-funded study
which investigated these issues. This study characterised treated sewage sludge (‘biosolids’) from
wastewater treatment plants employing different means of sludge treatment, examined surface losses
of various physico-chemical parameters following land application, measured metal uptake by
ryegrass, and modelled the potential impacts on human health