Everyone has that neighbor who they see dumping pesticides down the storm drain in the early morning hours when he thinks no one is watching. We probably all see solvents, antifreeze, and gasoline come along as well. Membrane technologies are improving in this area quite a bit. Our system tends to stick with using oxidoreductase enzymes. Coal bottom ash is another method, as is natural scolecite.
Each has been option has been studied and found to have adequate removal efficiencies. You can also still find recommendations online that say the activated sludge process is all you need. Probably the real determination in dealing with hazardous wastes is the amount and type being seen so that you can create a specified response.