CO2 produced in water treatment plants

3 Mio. tons of CO2 per year are produced by the 10.000 water treatment plants in Germany.

By the way, the total electricity consumption of the 10,000 wastewater treatment plants is around 4,400 gigawatt hours (GWh) per year. This corresponds to the electricity requirements of 900,000 four-person households or a CO2 emission of 3 million tons per year.

Source: https://www.umweltbundesamt.de/sites/default/files/medien/publikation/long/3855.pdf