Impacts and Implications of Climate Change on Wastewater Treatment Plants

Danilo Bertagna (ESR6)



Wastewater treatment plants (WWTP) have been playing a crucial role in keeping the environmental equilibrium and reducing pollution impact in waterbodies nearby highly populated centres. Nevertheless, these systems are vulnerable to the effects of climate change.

The most immediate effects would be changes in the water intake. In the case of severe floods and intense rainfall, groundwater infiltration and infrastructure damage would occur. Treatment performance would be affected due to inundation. Pumps would require more energy, and facilities built near sea level could be completely lost and submerged. In the case of intense drought periods, issues concerning smell would rise. Cavitation of pumps and damage to the pipe system could also happen. The increase in the average temperature would affect the solubility of oxygen, the metabolism of microorganisms and biodegradation processes, compromising established levels of BOD. Effluents with higher toxicity character and eutrophication potential could cause severe impact in rivers, lakes, and communities.

These impacts are not merely technical, but they cascade to social, cultural, economic, and environmental areas. They can cause loss of assets, the disruption of local business, isolation of villages, water rationing, destruction of biomes, extinction of species, increased incidence of diseases, and mental issues. In the case of the indigenous population, such a severe change in their environment could cause loss of identity and forced migration.

Many of these impacts are already taking place and action will be required immediately to avoid worse case scenarios. Governments have to act globally and locally to make critical long-term decisions relating to their WWTP infrastructure. Global warming needs to be considered during the project and design of new facilities and the update of existing ones. Stakeholders’ decisions need to be based on scientific evidence, using the best available information as tools for education and raising awareness campaigns. An open dialogue with the indigenous population should exist due to their unique relationship with the natural environment, socioeconomic deprivation, and increased susceptibility to disease. Indigenous knowledge and customs can be a valuable tool in responding to impacts of climate change, for example, through diverse approaches to adaptation, unique cultural governance and practices, and increased awareness of environmental change. It is essential to prioritize the most vulnerable, think in long-term adaptive policies using renewable resources, cooperate and collaborate with other countries, and consider the knowledge and experience of those affected and that they are involved in decision-making.

Disruption of water treatment systems and deterioration of water quality are just a few examples of the challenges we are to face in the next few decades if we keep ignoring these issues or choosing superficial solutions. There is clear and compelling evidence for the need to act now on climate change and adopt a precautionary approach because of the irreversible nature and scale of most of the risks involved.

Reference: J. Hughes, K. Cowper-Heays, E. Olesson, R. Bell, A. Stroombergen. Impacts and implications of climate change on wastewater systems: A New Zealand perspective. Climate Risk Management 31 (2020)
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