As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAS - AIR TURNBACK - FLT 113 - ON CLIMB-OUT OF LAS EN ROUTE TO LAX, VISUAL INDICATION OF LAVATORY BLUE JUICE WAS OBSERVED COMING FROM THE FRONT LAVATORY. MX COMPLIED WITH LAVATORY CLEAN UP PER AWA TASKCARD I1D38001. MX REMOVED PLASTIC BAG FROM DUMP VALVE. OPERATIONAL CHECKS OF THE LAVATORY WERE GOOD.