9:27 – moving of the de-grouting room over the beamtube for the last 2 grout pads 10:30 – de-grouting begins at Mid-Y. Dust monitor levels remained reasonable (less than 200 cts for 0.5micron particles) throughout the work H2 PSL enclosure building work continued. Dust monitor levels near the work spiked twice momentarily above 3000 cts for 0.5micron particles for less than 2minutes at a time. Otherwise, dust levels were reasonable.