Complex sentence: This refit included a new "green" wastewater treatment system in addition to the current Lloyd's certified system allowing its ability to reuse the wastewater after treatment rather than discharging the wastewater overboard into the sea.
Split into simpler sentences: This refit included a new "green" wastewater treatment system in addition to the current Lloyd's certified system. The new treatment system allows the ship to reuse the wastewater after treatment rather than discharging the wastewater overboard into the sea.