The invention relates to a method and system for treating an aqueous
liquid containing dissolved minerals and dissolved hydrocarbons. Method
steps and apparatus for treating a waste water feed stream are disclosed
which utilize a warm lime softening system in fluid communication with
the waste water feed stream, wherein sludge from the warm lime softening
system is recycled to improve lime utilization and enhance silica and
boron removal without the addition of an external source of magnesium. In
addition, a microfiltration system and/or an air stripper system may be
used in fluid communication with at least one reverse osmosis system to
produce a treatment water that meets state and federal guidelines for
surface discharge.