The post-apocalyptic landscape still holds some scars from the cataclysm. Pollution Deposits spread Pollution contaminating nearby buildings and causing Radiation Sickness. Use the Pollution Overlay to see the affected areas.
Building near Pollution Deposits comes with a risk. As they constantly spread pollution and occasionally release toxic chemicals, it would be best to avoid them as much as possible. Research Hazmat Engineering in the Tech Tree to build Environmental Stations to safely remove Pollution Deposits. The collected Pollution needs to be carefully stored in Waste Dumps—otherwise the containers have a great chance of leaking and even exploding! You can sell the collected waste to other colonies rather than building more Waste Dumps.
Buildings and pollution
Buildings exposed to too much pollution eventually become Contaminated. Contaminated buildings need to be decontaminated before they can be put back to full use. Some buildings like Outhouses create pollution themselves, which is good to keep in mind when placing them.
List of buildings that create pollution