Environmental forensics: pollution signatures

The presence of anthropogenic substances in the drinking water chain poses challenges for the water sector, and specifically for drinking water companies. That presence is undesirable, and sometimes even problematic. Although treatment techniques can remove pollutants, a reduction in emissions is highly desirable: if something isn’t there, we don’t have to remove it.

Information is often lacking about the sources and emission pathways of pollutants in surface water and groundwater, making it difficult to define measures that could reduce or prevent emissions. A large number of micropollutants are currently monitored regularly in sources of drinking water and specific emission pathways are sampled. Using advanced statistical methods, links between specific pollutants can be established in datasets of this kind. This allows for the identification of groups of substances that often occur together (‘signatures’) . These signatures can then be linked to sources or typical emission pathways.

The proposed method is a tool for the better visualisation of the relationship between the source, emission pathway and pollution profile in the water chain and this is therefore a step towards understanding the impact of pollution sources and emission pathways. These signatures can ultimately be linked to non-target screening (or screening in general) to prioritise features that are included in signatures for further identification or to evaluate how comprehensive monitoring programmes are.