On September 9th in the morning Ron Kuramoto noticed that the T2 cooling package expansion tank level was reading NOT OK for the warning level.  Looking at XSTRIP showed that the warning level tripped at approximately 1:50am on September 8th.  The tank was refilled at 4pm on September 9th to the usual level (1/2" above the nut on the trip level float).  The expansion tank level will be checked tomorrow and periodically throughout the week to determine if there is a water leak, and if so what the leak rate is.  Note that there has been no significant change in BL1A vacuum, so a water leak into the vacuum volume is not suspected.