Cities: Skylines II · Water and sewage
Wastewater Treatment Plant
The Wastewater Treatment Plant treats wastewater to avoid polluting surface water sources, according to the official progression feature.
How it works
Paradox names the Wastewater Treatment Plant as a Development Tree unlock a player might choose to reduce pollution of surface water sources. Shacknews separately says water treatment plants take care of sewage water and turn the waste product into garbage that can support recycling and waste-management programs. The sources do not provide treatment capacity, point or construction costs, or a complete set of operating effects.
Read the supporting references
Cities: Skylines II Feature Highlight #10: Game Progression - Paradox Interactive Best early development tree upgrades - Cities: Skylines 2 | Shacknews
Check the edition and source version for patch-specific details. Guide methodology.