Earlier this month, there was a documentary on the sewage system in Flanders, by a well-known news agency. The documentary focused on 400 000 homes that are not connected to the sewer system, still discharging municipal wastewater in our waterways. This can have devastating effects on the local ecosystems and the overall quality of local waterways. This documentary caused quite some controversy. Some thoughts below.
Waterways have something called a self-purification capacity, meaning pollution in the waterway is removed by biological activity in the rivers. However, when the pollution rate exceeds the self purification capacity, the quality of the waterway decreases.
"The fact that wastewater must be treated before discharge in the environment is in most cases very important."
The documentary stresses the need for placing sewer pipelines to all households, so the wastewater is collected for centralized treatment. Whether placing pipelines to all homes is the right decision, however, is very debatable. The documentary does not mention the option for decentralised wastewater treatment, for example. Such systems can purify wastewater on a local scale, even on household level, to ensure the local environment is protected.
Decentralized systems prevent the need for placing pipelines to remote areas, which is a huge cost on its own, let alone the infrastructural works needed to break open and close down streets.
Maintaining our tremendous network of sewage pipelines is very costly. Potential leakages in our network play an important role as well in terms of pollution. Where feasible, preventing excessive piping is a very interesting alternative to be considered.
Decentralized treatment could even be coupled to reuse. Non-potable reuse for irrigation or toilet flushing, for example.
Rainwater capture and purification to drinking water quality could then provide the homes with water and make them independent from the centralized grid. Sewers in urban areas or more densely populated areas for centralized treatment have their advantages, but for remote areas, decentralized systems and self-sufficient homes can prevent kilometres of piping. Cost-effective alternatives and expertise are available.
The fact that there are many actors involved in decision making does not help for efficiency in the sector. A more efficient decision-making process and a more effective collaboration between actors in the sector (or involve less actors) could increase efficiency.
Communication is something that should not be underestimated either. Many citizens have no idea about the efforts behind the scenes to provide drinking water and to treat wastewater. Improved education and communication could create a better support base in our society. It could increase attention given to the water sector, increase the willingness to pay for our precious resource and could facilitate to better provide such services.
In general, the documentary didn’t cover all aspects and knowledge on how it could be done better. The main message, however, that there is a need for better management of our wastewater, is undisputable. Instead of pointing fingers and covering our own tracks, let’s gather all expertise, all actors and work together towards more efficient management of our wastewater.Together we’ll build a water efficient society💧