Posted below are plots for the PSL Chiller water usage for the past 2.5 years. 

   Water usage in the Crystal chiller appears to be constant between 300ml and 100ml per week. It should be noted water is not added every 7 days, but as it is needed and per the operator's FAMIS task. The average is one week between top offs. The water usage in the Diode chiller is not tracked as it's reservoir is much larger and only needs occasional attention. 

Service timeline of the two chiller:    

   The chiller known as Gromit (S/N Crystal 64150, Diode 63793)was in service from May 2015 until May 2016. It was put into backup for annual maintenance rotation.  

   The chiller known as Wallace (S/N Crystal 44801, Diode 44807) was in service from May 2016 until September 2016. It was put into backup for service due to Crystal chiller trips. The faulty Crystal chiller controller was replace. 

   The Chiller known as Gromit was in service from September 2016 until February 2018. It was put into backup for annual maintenance rotation. 

   The Chiller known as Wallace is in service as of February 2018.