Background
Since 1930, global chemical production has increased from 1 million to 400 million tonnes per year, with a steep increase of for instance plastic, pesticide and pharmaceutical production since the 1950’s. Never before have chemicals been so prevalent in society and our daily lives. And the number of new substances and new usages is ever increasing. Thousands of these chemical compounds are emitted to aquatic systems where they can accumulate and lead to negative effects on aquatic organisms.
Out of the 615 wastewater treatment plants (WWTPs) close to the Baltic Sea coast, 45 plants receive wastewater from more than 100 000 connected persons and together treat wastewater from almost 70% of the coastal population.
Upgrading these large WWTPs with advanced treatment technologies would on average remove 70-80% of the micropollutants in outgoing water, reducing the total load from all coastal WWTPs by approximately 50%. This measure has potential to significantly lower concentrations of a wide range of micropollutants in seawater, thereby enhancing the protection of this sensitive water body.
Recommendations
- Create legal incentives to encourage implementation of advanced wastewater treatment. As is the case for nutrients and organic matter today, treatment efficiency requirements or threshold levels of concentration of chemicals could be included in new legislation related to wastewater such as the revision of the Urban Waste Water Directive or in legislation for water reuse. Increased demands can be put on large facilities where absolute emissions are high and costs per treated volume of water are lower due to upscaling effects.
- Facilitate forerunners by making financial instruments available for pilot studies and technical upgrading of WWTPs where there is a will to go beyond current legal requirements.
- Ensure policy coherence and full implementation of the Water, Marine and Urban Waste Water Directives. More measurements of the Priority Substances are needed to complete the assessments of Good Environmental Status. Further expansions of the risk assessment and monitoring of environmental pollutants should be included in future Programmes of Measures for the Water Directive.
- Enable science based policy support by investing in research to evaluate the importance of wastewater treatment plants as collection points for urban chemical flows to the aquatic environment. Innovative methods to monitor concentrations of a wide spectrum of chemicals and total effect of the chemical mixture are needed to go beyond the single chemical approach that is currently applied.
Read and download:
Policy brief: Advanced wastewater treatment (519 Kb)
CONTACT
Emma Undeman
Environmental chemist, Baltic Eye, Baltic Sea Centre
+46 (0)8 16 34 26, emma.undeman@su.se