Cleaning wastewater for sewer

I have a washwater stream generated from washing used automotive parts.

The spent washwater is high in metals and very high in oil & grease.  Solids
settling from this wastewater almost always pass TCLP testing, and are
therefore landfillable.  But the water itself does not pass city sewer
reguirements for copper and oil & grease.

Does anyone have advice or recommendations for removing oil & grease from
this water?

--
Paul Konigmacher
Unit Parts Company
OKC, OK, USA