Treating wastewater to protect people and ecosystems

The challenge
Our global water resources are under pressure. In many countries, decades of uncontrolled and untreated wastewater discharge have resulted in severe environmental degradation of both inland and coastal waters. Even today, less than half of the world’s wastewater is collected and less than 20 percent is treated. This is a serious environmental challenge and one that also poses a threat to the long term sustainability of access to clean water sources for drinking water.

The future
Simply improving the percentage of wastewater that is collected and derived from human settlements is not enough to ensure water security in the long run. UN’s SDG 6.3 seeks to halve the proportion of untreated wastewater discharged into our water bodies by 2030. This requires increased treatment capacity and optimisation of the treatment process to ensure that the final effluent discharge complies with the required quality standards according to the vulnerability of the receiving water environment.

Explore associated sectors

Ensuring a proper water quality in our various water environments requires a sustained effort and a combination of both efficient treatment technology and proper regulation. In fact, introducing stricter regulatory standards for wastewater treatment efficiency and effluent requirements can be a driver for innovation and contribute to the restoration of vulnerable water environments.

In many regions, there is a massive need for expanding the sewer networks and constructing new or upgrading existing treatment plants. However, designing the most cost-efficient wastewater infrastructure can be a great challenge. The optimal design depends on many local factors, including population density. In rural areas, a combination of smaller local treatment plants and decentralised low-technology solutions tends to be the most cost-efficient structure. In urban areas, a structure with fewer and larger centralised treatment plants is often the most cost-efficient as the large volume of wastewater also makes it possible to utilise the potential for energy and resource recovery from the treatment process. Moreover, this presents an economic opportunity for the wastewater utility as it can lower its energy costs and even serve as a source of revenue, if the surplus energy is sold back to the grid. With climate change causing more frequent flooding, wastewater utilities also need to integrate stormwater management in their design of wastewater infrastructure.

In many countries, industrial wastewater pose a special threat to both human health and the environment. History includes numerous examples of untreated wastewater from industries causing severe environmental problems to the receiving water body. However, even releasing it to municipal sewerage systems can pose problems as the traditional wastewater treatment plants are often not equipped to handle the complex composition and the harmful substances which industrial wastewater contains. Fortunately, several solutions exit for treating industrial wastewater at the source before it is released either to the local sewerage system or directly to the recipient. In addition, these often have a low payback time.

Connect with us: Tanya Gottlieb Jacobsen, Deputy Director and Head of Water & Climate Change Adaptation, [email protected]

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