Date: 201209
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
ATC / advisory: Ramp ZZZ
Aircraft component: Potable Water Storage; control; indication
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer
Human factors: Workload; Troubleshooting; Confusion; Communication Breakdown
Second reporter function: Captain
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Pre-flight
Result: General Release Refused / Aircraft Not Accepted
Contributing factors: Aircraft; Company Policy; Manuals; Procedure
Primary problem: Procedure

Narrative: The aircraft came in with an MEL regarding the aircraft failing potable water test. After studying the MEL; the Captain and I believed the aircraft was not in compliance with the MEL. The plane was written up as having failed the test about a week ago. The Captain and I read the MEL to say that the aircraft had to be disinfected and retested within 48 hours of the failed test. The logbook did not indicate any retest or corrective action of any kind since the original test fail write-up. The Captain first talked with a line mechanic who said he thought we could go; but was not adamant about us taking the plane. Next; the Captain got on the phone with Maintenance Control. They indicated their interpretation was that the plane was good to go without any documentation of disinfecting or retesting. The Captain and I disagreed with them. Next; the Captain got on the phone with the Chief Pilot on Duty who seemed to be reading the MEL as well and said we could take the plane. The Captain; with my support; elected to refuse the airplane based on our evaluation of the MEL. At some point; the Captain was back on the phone with Maintenance; Dispatch; and the Chief Pilot. This time it seemed that there was concurrence that the MEL did require disinfecting and retesting; but that had already occurred. At this point; the Captain asked that a line mechanic come out and make a logbook entry indicating the required test had been accomplished. Maintenance Control said that was not going to happen. He [the Captain] asked that some form of documentation be sent to us to take with us in the logbook. That was not granted either. Maintenance Control told the Captain that there was a non-routine card where this type of information is recorded; and it is kept in a maintenance base file. They said the FAA checks with Maintenance Control any time this issue comes up. Neither the Captain nor I had ever heard of this document before today. Maintenance Control told the Captain that the disinfection and retest had been accomplished within 48 hours; it was on file in (city); and we were legal according to the MEL. We agreed that statement satisfied the MEL requirement; and we accepted the aircraft. We were puzzled by the lack of documentation provided to the crew to satisfy this MEL. Ultimately; the Captain and I just wanted a solid way to defend our decision to take the aircraft. With no documentation of the required disinfection and retest; we felt that we did not have legal defense for accepting the aircraft. It seems that crews need some information about the 'non-routine card.' MELs that are satisfied by documents that the crew doesn't have access to is problematic.


Second narrative: [Narrative 2 contained no additional information.]


Synopsis: A flight crew refused to fly a B737-800 after a logbook entry stated 'potable water failed EPA testing; needs disinfected' but did not contain a sign off after the required 48 hour compliance period.