"Proportion of population served by municipal wastewater systems, selected countries, 2023",,,,,, ,,,,,, Country,No treatment (percentage),Unspecified treatment (percentage),Primary treatment (percentage),Secondary treatment (percentage),Tertiary treatment (percentage),Total (percentage) Israel,2.3,1.4,2.0,31.2,63.2,100.0 Luxembourg,0.5,0.0,0.6,11.5,87.4,100.0 Netherlands,0.0,0.0,0.0,0.0,99.7,99.7 Switzerland,0.3,0.0,0.0,8.0,90.0,98.3 Austria,0.0,0.0,0.0,1.2,95.1,96.2 Korea,0.4,0.0,0.0,0.7,94.2,95.4 Australia,0.0,0.0,16.5,26.6,49.7,92.9 Denmark,0.0,0.0,0.1,1.0,91.2,92.3 Norway,1.5,0.0,23.6,9.1,54.4,88.5 Belgium,3.5,0.0,0.0,5.4,79.0,88.0 Czechia,2.2,0.0,0.1,7.3,77.1,86.7 Canada,0.8,0.0,12.9,42.9,29.3,85.9 Finland,0.0,0.0,0.0,0.0,85.0,85.0 Hungary,2.9,0.0,0.1,6.8,73.8,83.6 Estonia,0.0,0.0,0.0,2.0,81.0,83.0 Lithuania,0.0,0.0,0.1,7.1,70.9,78.1 Latvia,0.0,0.0,0.5,21.9,55.1,77.5 Poland,0.3,0.0,0.0,14.4,61.5,76.2 Slovak Republic,0.3,0.0,0.1,68.9,2.2,71.5 Slovenia,0.0,0.0,0.0,25.2,44.4,69.6 ,,,,,, "Note: Totals may not add up due to rounding. The countries presented in the table correspond to all the members countries for which data are available for 2023 in the Organisation for Economic Co-operation and Development's wastewater treatment database. Similar data for Canada, obtained through Statistics Canada, is also included. For Canada, only the population served by municipal wastewater systems with a daily flow of 100 m3 or more was considered.",,,,,, Source: Organisation for Economic Co-operation and Development (2025) Connection rates to wastewater treatment database (https://stats.oecd.org/index.aspx?DataSetCode=water_treat). Statistics Canada (2025) Population served by municipal wastewater systems by treatment category (https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=3810012501).,,,,,, Available on the Environmental indicators website (www.canada.ca/environmental-indicators).,,,,,,