Reporting on industrial wastewater treatment remains limited, with data only reported from 22 countries representing 8 per cent of the global population. In these countries, only 38 per cent of industrial wastewater was reported as treated, and only 27 per cent was safely treated.

https://www.who.int/publications/b/75389

I know this is from 2022, but still.

in low-income and middle-income countries (LMICs), grab sampling from surface waters, open drains, and pit latrines was more typical.