Yesterday I surveyed the CPS grounding systems and found the ITMY racks lacking anything explicit.  There is of course, in theory, grounding by virtue of the rack sitting directly on the unistut attached to the chamber.  However, as per T1300871, the grounding is expected to be from the board 'Target Ground' lugs to the chamber.  At noon yesterday, I added this to the three BSC1 CPS racks.

Below is spectra from Tuesday am and Wednesday am so a before and after view.  The Blends are in the same state (PCOMM JimW) and we are in all ways, in the same configuration.  The ground motion could be different of course.