Environmental Impacts Of Finnish Drinking Water Production

Abstract

Drinking water treatment is a process that typically requires substantial energy input and can be associated with various environmental impacts, including climate change, resource depletion, and ecotoxicity. However, life cycle assessment (LCA) data for this sector often lack regional specificity, which limits the reliability of impact evaluations. Publicly available LCA databases, such as Ecoinvent, do not include regional data—LCA datasets—that adequately reflects Finnish drinking water treatment practices. To address this gap and support a comprehensive life cycle assessment (LCA) of drinking water production in Finland—reflecting current treatment technologies and electricity consumption—a life cycle inventory (LCI) was developed for three prevalent Finnish drinking water production methods: conventional surface water treatment, groundwater with chemical treatment, and artificially recharged groundwater. The LCI covers approximately 40% of Finland’s annual drinking water production and was used to generate process-specific datasets. Impact assessment using these new datasets revealed that artificially recharged ground-water generally has the lowest environmental impacts, though its performance is affected by the use of polyaluminium chloride (PACl) in pretreatment. Groundwater treatment showed the highest impacts, primarily due to its heavy reliance on electricity, while surface water treatment, despite intensive chemical use, benefited from lower energy demands. Climate change impact values were 0.147 kg CO₂-eq/m³ for groundwater, 0.122 kg CO₂-eq/m³ for artificially recharged groundwater, and 0.119 kg CO₂-eq/m³ for surface water. These values are lower compared the quantifications on climate change impacts done by other studies, due to differences in inventory, methodology and coverage, and especially energy sources. Comparison with Ecoinvent 3.11 datasets highlighted substantial differences, driven by updated electricity mixes, coagulant types, and energy consumption levels. This led to reductions in climate change impacts quantification by 46% in surface water treatment, 53% in groundwater treatment and 70% in Artificially recharged. A sensitivity analysis incorporating Finland’s current electricity mix—dominated by nuclear and wind power—showed a 79% reduction in CO₂-eq/m³ for groundwater treatment, making it the least impactful option under updated conditions. In contrast, surface water and artificially recharged groundwater showed smaller reductions (26% and 42%, respectively), due to their greater dependence on chemical inputs.