B757 CREW HAD NO POTABLE WATER.

Narrative

AFTER TKOF; DURING CLBOUT; WE WERE INFORMED THERE WASN'T POTABLE WATER AVAILABLE ON THE ACFT. I INFORMED THE #1 FLT ATTENDANT TO CHK AND MONITOR THE WATER TANK GAUGE IN THE FIRST CLASS GALLEY. THE TANK READ FULL (60 GALLONS) AT THE TIME. AT CRUISE (FL350) THE WATER TANK GAUGE INDICATED 55 GALLONS. THE PLANE HAD A 2 - 2 1/2 DEG NOSE UP ATTITUDE AND I ATTRIBUTED THE DIFFERENCE TO THAT. THE QUANTITY STABILIZED AT 55 GALLONS. ABOUT 45 MINS IN CRUISE I WENT BACK TO CHK THE QUANTITY GAUGE MYSELF. AT THIS TIME IT INDICATED 50 GALLONS. DURING THE CRUISE PHASE; I COMMUNICATED WITH DISPATCH THAT WE DIDN'T HAVE WATER AND SUSPECTED THE WATER SVC VALVE WASN'T FULLY CLOSED; AND THAT IF WE SAW THE QUANTITY DECREASING WE COULD BE DEVIATING. THERE ARE NOT ANY PROCS; INFO; OR GUIDANCE IN ANY OF OUR MANUALS ON THE WATER SYS FOR THE B757/767. SEEING THAT THE WATER LEVEL HAD DROPPED TO 50 GALLONS; I MADE THE DECISION TO DEVIATE. AFTER THE DECISION WAS MADE; WE STARTED TO HEAR MUFFLED THUDS AGAINST THE R SIDE OF THE ACFT; THAT COULD BE MISTAKEN FOR GALLEY NOISE IF IT WEREN'T FOR THE #1 FLT ATTENDANT INQUIRING ABOUT SAID NOISE. I INFORMED DISPATCH OF THE LATEST DEVELOPMENTS AND TO HAVE MAINT MEET THE ACFT AS WE SUSPECTED THERE MIGHT BE POSSIBLE DAMAGE TO THE ACFT FROM SHEDDING ICE. WE PUT THE R ENG IGNITION ON CONTINUOUS AND STARTED OUR DSCNT. LANDED AT DENVER 30 MINS LATER WITHOUT ANY FURTHER PROBS. THE PLANE WAS OVERWT BY 11500 LBS. THE LNDG WAS SMOOTH AND UNEVENTFUL. THE GND CREW AND MAINT WERE WAITING FOR US WHEN WE ARRIVED. INSPECTION OF THE WATER SVC VALVE CONFIRMED THAT WATER WAS LEAKING DUE TO THE VALVE NOT BEING FULLY CLOSED. WATER QUANTITY INDICATED 40 GALLONS AT THIS TIME. ACFT WAS INSPECTED FOR DAMAGE (NONE FOUND; AND AN OVERWT LNDG). DISPATCH WAS INFORMED BY PHONE TO WHAT HAD TRANSPIRED TO THIS POINT; AND WE WERE ON OUR WAY TO SFO 45 MINS LATER. IF I HAD NOT BEEN TOLD (BY A FLT ATTENDANT INVOLVED) OF AN INCIDENT A FEW WKS EARLIER OF A B757 FROM DFW TO RDU THAT SUSTAINED MAJOR DAMAGE PARTLY DUE TO AN OPEN WATER SVC VALVE AND THE CREW NOT REALIZING IT UNTIL THE WATER TANK LEVEL DROPPED BELOW 1/2 TANK. THE SYMPTOMS WERE THE SAME -- NO WATER; THUDS ON THE SIDE OF THE ACFT. THEY WERE UNFORTUNATE TO HAVE THE LAVATORY SVC VALVE OPEN ALSO. AS I STATED EARLIER; THERE IS NOT ANY INFO OR PROCS THAT CAN GIVE YOU ANY GUIDANCE ON THE WATER SYS OR ITS OP THAT I CAN FIND. FROM MY OBSERVATION OF THE WATER SVC VALVE ON PLANE NXXX; THERE IS A FLAW IN THE DESIGN. THE WATER SVC HANDLE MOVES R TO L (OPEN TO CLOSE) IN ABOUT A 100 DEG ARC. THE VALVE HANDLE WAS FOUND ABOUT 5 DEGS FROM FULL CLOSED WITH THE SVC DOOR SHUT. THAT 5 DEGS ALLOWED WATER TO LEAK OUT AND CAUSE POSSIBLE DAMAGE TO THE ACFT. THERE NEEDS TO BE SOME MECHANISM THAT DOESN'T ALLOW THE DOOR TO SHUT UNLESS THE VALVE IS FULLY CLOSED OR AT LEAST A VISUAL CUE (RED ARC IN THE NOT FULLY CLOSED AREA WITH A GREEN LINE WHERE IT IS). ALL IT SAYS NOW IS OPEN ON ONE SIDE; CLOSE ON THE OTHER. THE VALVE HANDLE TRAVELS ABOUT 8-10 INCHES WITH THE LAST INCH BEING THE MOST CRITICAL. THE DIFFERENCE OF LEAKING OR NOT. IT WOULD BE VERY EASY TO MISTAKE THE VALVE TO BE CLOSED IN THE POS IT WAS FOUND ON OUR ACFT. ANOTHER PROC THAT COULD BE USED IS HAVE THE GATE AGENT OR THE #1 FLT ATTENDANT CHK TO SEE IF THE WATER IN THE LAVATORIES RUNS AND THE LAVATORIES FLUSH JUST BEFORE CLOSING THE FORWARD ENTRY DOOR. OUR FLT ATTENDANTS ASSUMED THAT THE WATER WAS WORKING BECAUSE THEY COULD BREW COFFEE AT THE GATE; NOT KNOWING THAT THE COFFEE MAKERS HAVE THEIR OWN RESERVOIR. IT WASN'T UNTIL THEY TRIED TO BREW A POT AFTER TKOF THAT THEY NOTICED THERE WASN'T ANY USABLE WATER.