The company that manages water service at Tokyo's Haneda Airport says it hopes to restore the supply to Terminal 2 on Friday if its quality test finds no problem.
The company suspended water service to the airport's two terminals for domestic flights on Wednesday morning in response to complaints that tap water tasted salty.
Water supply to Terminal 1 was restored later in the day. But Terminal 2 still remains without water, leaving many restaurants unable to operate. Passengers also cannot use tap water at restroom wash basins.
Investigations by the company and the transport ministry detected salt in water stored in one of the four tanks for Terminal 2 and in tap water at a facility to wash aircraft.
The company is checking water pipes near the washing facility and the tank in question, which are about 1.2 kilometers apart.
The firm has washed out the tank and is testing the quality of water now being stored in it.