What was found
WASTE DISPOSAL MIDLAVG -LAVATORY WASTE SYSTEM PROBLEM WAS ENCOUNTERED BY FLIGHTCREW WHICH IS NOT COVERED IN FAULT CODE DIAGRAMS MULTIPLE LAVS OVERFLOWIN G. 2 OPERABLE LAVS ARA ALMOST FULL LOCKING TO VERIFY POSITIVE FIX. UNLOCKING FOR UPDATE. DEBRIEFED FLIGHT ATTENDANT UPON ARRIVAL, THEY INDICATED THE FLUID AT MID LAV BOWL WAS FILLING UP, AND THE FWD FIRST CLASS LAV BOWL WAS AT NEAR FULL LEVEL. AND SAID THE AFT LAVS HAD NO ISSUES OF BOWLS FILLING UP. FLUSHED ALL LAVS FOUND NO STANDING FLUID IN THE BOWL AND NO INDICATION OF FILLING UP. PUSHED DOWN ALL BOWL FLAPPERS AND INDICATE AT SERVICE LAVEL. INSPECTED ALL 4 LAVS AFTER SERVICING AND FOUND ALL LAVS TO BE AT PROPER PRECHARGE LEVELS. FLUSHED EACH LAV AND FOUND ALL ARE FUNCTIONING NORMAL WITH FRESH BLUE FLUID. ALL LAVSARECLEAN&SERVICEABLE.ATARRIVALPERFORMEDVISUALI NSPECTION OF ALL LAV TANKS AND APPEARED TO BE AT SERVICED LEVEL, NO STANDING FLUID IN THE BOWLS,NO BLUE WATER SPILL INSIDE ALL LAVS. ALL LAVS OPERATING NORMAL.