Factorio Forums

I was playing through the campaign levels on 0.16 and discovered that in the final level there is no pollution. That resulted in me having no biter attacks. At first I thought it was just because I'd cleared the nearest bases as the first thing in the level, but then I looked at the pollution overlay on the map and found that there was zero pollution. The debug setting to show polluted chunks similarly showed no chunks with pollution.

Here's the map view of my base with the pollution overlay turned on:

Thanks for the report.
That is by design. Campaign is heavily is scripted, so pollution is turned of in some missions so that evolution and attacks are fully controlled by the campaign script.