This leak appears to be an effect of the overpressure event of the cooling lines at Y-End, reported here, and it makes sense as to why the loss of glycol reported there too.  I was notified by Richard that someone reported a leak at Y-End, headed there and found the leak, probably had leaked for days.  The leak is located on the copper return line, probably a busted solder joint.  To stop the leak, I closed the supply and return valves, see photo, they'll remain closed until the leak is fixed.  Jordan and I let some pigs loose on the spill, they'll be picked on the next couple of days.

Unfortunately, now we have to check the condition of the hepta pump, since the pressure on the cooling lines went well above 100 psi, nominal operation conditions for such pump is a maximum of 88 psi.