Let's say I am growing Blossoms and got polluted water into farm tile. There is no way to remove polluted water without destroying and rebuilding farm tile.
Steps to Reproduce
Build hydroponic farm tile, select Blossom as a seed. Pump polluted water into tile. Click "empty storage" - nothing happens.
Status: Known Issue
We are aware of this issue and have it logged internally but either we do not have a fix ready yet or we are not planning on addressing the issue in the immediate future.