The efficiencies of subsoils for on-site wastewater disposal with respect to endocrine disrupting chemicals

Abstract

Septic tanks and other on‐site systems are a common means of disposing domestic wastewater effluent in Ireland. In assessing site suitability, subsoils below the percolation trench have an important role in attenuating pollutants and hence in protecting groundwater. As part of an investigation into the hydraulic performance of treatment systems at four sites in Ireland with different subsoil characteristics, a series of samples were analysed for endocrine‐disrupting chemicals (EDCs), including oestrogens, surfactants and organic oxygen compounds. EDCs were found at all four sites, but only at low concentrations (often below those at which their presence could be confirmed) and generally only in samples known to be percolating effluent. Further research should target oestrogen compounds, as these appear to be present in higher concentrations than the other EDCs and also have greater potency.