Summary

Municipal wastewaters contain a wide range of contaminants that may pose a hazard to human health where there is exposure to untreated or partially treated effluents (e.g., during flooding events), or where these contaminants are not fully removed by treatment processes. Previous reports prepared for the Ministry of Health have identified several classes of contaminants of particular concern for human health present in municipal and industrial wastewaters, based largely on international data. The aim of this report is to provide an overview of what is known about the presence of contaminants from one of these classes, heavy metals, in effluents from municipal wastewater treatment plants in New Zealand.