Last Thursday at Port Canaveral, while CARNIVAL ELATION was discharging water from its ballast systems which helps stabilize the ship for navigational purposes, a grey water valve failed and unintentionally discharged grey water from non-sewage waste water systems.  

A spokesperson for Carnival told World Maritime News that: "Last Thursday at Port Canaveral, while Carnival Elation was discharging water from its ballast systems which helps stabilize the ship for navigational purposes, a grey water valve failed and unintentionally discharged grey water from non-sewage waste water systems.” 

Gray water typically contains the combined wastewater streams from the ship's sinks, showers, laundry facilities and galleys. It is not classified as sewage, but U.S. EPA testing has determined that for certain ship types, the average contaminant concentrations in gray water may exceed the levels found in untreated domestic sewage. The EPA Vessel General Permit regulatory scheme specifies that while pierside, large cruise ships "must either discharge to appropriate reception facilities, hold graywater and discharge when the vessel is underway, or treat graywater with a device to meet discharge standards."

Maritime Business World