Dataset - CKAN MobiDataLab

Degree of connection to the public sewage system - key dates - regional depth...

Degree of connection to the public sewage system - key dates - regional depth: districts and free cities
- https://www.iana.org/assignments/media-types/text/csv
Degree of connection to the public sewage system - reference dates - regional...

Degree of connection to the public sewage system - reference dates - regional levels
- https://www.iana.org/assignments/media-types/text/csv

You can also access this registry using the API (see API Docs).