How much are you willing to pay extra in your annual water bill to reduce concentrations of chemicals in your river?

How much are you willing to pay extra in your annual water bill to reduce concentrations of chemicals in your river?

Do you know how much you are paying this year for your potable water and management of your wastewater? I know it! The Catalan Water Agency (ACA) prepares every year a report on the cost of water in Catalonia. In July 2016, ACA released the last version which can be downloaded here.

ACA estimated that, for an average water use of 144 m3/household/year, the total water bill was 355 €/household/year (VAT included). The water bill was split in 3 components: cost of water supply, wastewater and a water tax. 221 €/household/year corresponds to water supply, 32 €/household/year to the management of wastewater and 102 €/household/year to the water tax. ACA uses the water tax to finance e.g. the require investments at the WWTPs. ACA also released a second report on the cost of water in Spain and Europe. It is very interesting to see how the cost of water increases as we move from the South to the North of Europe. For the same average use of 144 m3/household/year, Athenians and Romans pay around 142 €/household/year and 200 €/household/year respectively. On the other side, Bristol and Berlin citizens pay 712 €/household/year and 620 €/household/year respectively.

This information resulted to be very useful for my research. We optimized (model-based) the total cost of upgrading the WWTPs with more advanced treatments to reduce concentrations of pharmaceuticals below harmful limits at river basin scale. We conducted the optimization for the Llobregat river basin (the river who supplies Barcelona citizens with water). More than 1 million inhabitants are living here! Assuming that every household in the Llobregat contributes to the payment of the WWTP upgrades, we estimated that upgrading the optimal WWTPs would represent an increase in the household’s water bills from 14 to 30 €/household/year. In percentages, this means an increase from 14% to 30% in the water tax and an increase from 4% to 8% in the total water bill. We hope we will be able to publish our methodology and results soon!

In this paper, we compare the previous optimqal cost with the estimated average willingness to pay per household for upgrading the WWTPs in Switzerland. We observed that the increases in the water bill calculated for the Llobregat would be fully acceptable by the Swiss since they are willing to pay an extra amount of 86 €/household/year (I strongly recommend to read the paper published by Ivana Logar, Roy Brouwer, Max Maurer and Christoph Ort in the journal Environmental Science and Technology in 2014 concerning the Cost-Benefit Analysis of the Swiss National Policy on Reducing Micropollutants in Treated Wastewater ). I hope ACA can conduct a similar study in the near future to evaluate the real willingness to pay of the Llobregat residents!