In 2012, Metropolitan Water District of Southern California in Santa Ana lowered their Cadmium (Cd.) limits for the industrial dischargers. Cherry Aerospace still utilizes a precipitation technology for treatment of their oily wastewater along with other waste streams comes from the batch treatment and alkaline cleaner line, that has been in operation since 1980s. This system could not meet the newly adopted discharge limits for Cd. SRI installed a polishing system, which was consisted of a High Efficiency Media (HEM), Granular Activated Carbon (GAC) and two Cd ion exchange columns in series to capture the wastewater from the clarifier and polish it for Cd. Before directing it to the Sanitary sewer system. This system has been consistently meeting the discharge limits and keeping Cherry Aerospace in Compliance.