Advanced wastewater treatment: A way to follow the precautionary principle?
Our society is experiencing a chemical intensification where the use pattern has changed from the use of few chemicals in large quantities, often from point sources, to the use of many chemicals in small quantities, such as chemicals in consumer products, and from diffuse sources.
Identifying hazardous substances and legislating one-by-one takes too much time. So acting on incomplete evidence following the precautionary principle should be seen as an alternative.
One such precautionary approach is advanced wastewater treatment which can significantly reduce the emissions of both known and unknown substances to the aquatic environment.
Chemicals enter the sewage system for example when we wash textiles, wash off personal care products or flush down pharmaceuticals that have passed through our bodies. Wastewater contains thousands of compounds with human origin and collects many of the urban chemical flows.
But the majority of urban wastewater treatment plants in the EU today are not designed to remove these so called micropollutants.
If we want to ensure long-term sustainable exploitation of marine and freshwater resources it is important that the end wastewater does not contain high levels of harmful substances. The starting point needs to be to limit the use of harmful chemicals at the production stage.
As we are exposed via multiple pathways, having a source control approach and ensuring enforcement of the polluter pays principle is crucial to protect human and wildlife health.
It also facilitates the transition to a circular economy as the presence of problematic chemicals in products impedes optimal recycling of materials, as well as reuse of water and sludge.
(Article by Emma Undemann, environmental chemist and researcher at Stockholm University; shortened)