project

Getting to grips with indirect discharges

Water authorities, environmental services and municipal authorities are increasingly seeing discharges of large quantities of chemical waste and other undesirable substances into the drains and therefore indirectly to surface water. That results in damage to the infrastructure of wastewater treatment systems and the drains system, as well as the nature and the quality of drinking water sources. KWR brings stakeholders together and conducts research to establish an overview of discharges. By combining different types of information and analysing it using advanced techniques, we can determine the origin of the substances that are found. The resulting picture of the extent and origin of chemical waste discharged in a given area provides stakeholders with action perspectives for tackling emissions.

Discharges of chemical waste: a problem with major consequences

Water authorities, environmental services and municipal authorities are increasingly seeing incidental and structural discharges of large quantities of chemical waste and other undesirable substances into the drains and therefore indirectly to surface water. That results in damage to the infrastructure of wastewater treatment systems and the drains system, as well as the nature and the quality of drinking water sources. The operation of a wastewater treatment plant may be temporarily disrupted by a discharge of chemical waste if the bacteria die or the drains system has to be replaced because of damage caused by major changes in the acidity of the water in the drains. Chemical discharges affect nature and can lead to the degradation of biodiversity in specific areas. Discharges near drinking water sources can lead to the suspension of intake for the production of drinking water. Chemical waste discharges are therefore a problem with major consequences.

Research provides action perspective

KWR conducts research to map out discharges by measuring anomalies in the physical-chemical properties of sewage. In addition, large-scale data analysis can determine why substances enter water or groundwater. Chemical analyses allow us to identify the substances involved. We can also draw on established or experimental toxicity data to determine the potentially adverse effects on the aquatic environment. By combining information about substances with other available information, we can determine the origin of the substances that are found. The resulting picture of the extent and origin of chemical waste discharged in a given area can help government bodies such as water authorities, and municipal and provincial authorities, with their permit procedures, supervision and enforcement work. Getting to grips with discharges also provides operational organisations, such as environmental services, with a firmer footing and action perspective.

The power of collaboration

Collaboration is essential given the complexity of the research and different areas of expertise required. We bring the stakeholders together and establish the connections required to do the research well. This allows us to take samples at the right time, to make changes to the existing infrastructure where necessary, and to make the best use of additional information for the interpretation of research results.

In addition to organising and coordinating the research, our chemical laboratory, with its advanced equipment and knowledge, takes measurements to identify the discharged chemical(s) so that we can determine their identity and origin.

In follow-up research, we can focus on the risks of chemical discharges for the quality of surface water and groundwater (WFD), damage to the environment (ecotoxicity) and impact on the (microbiological) ecosystem. In addition, the complexity of the underlying problem requires a deeper understanding of the legal and governance issues relating to discharges into the drains system. We explore the needs and constellations of stakeholders and deliver insights on the road to effective governance arrangements.