1. Update of Water Station Changgen Yang

2. Main water purification station is 100m south of the intersection point of the construction tunnel with main tunnel. It is ~990 m to far site, ~710 m to DYB near site. ~570 m to LA near site. Main water station

3. Main water system 15 m x 8 m 1 m + 9 m

4. Water circulation room 4 m x 10 m Gas room 3.5 m x 10 m Gas bottle cabinet Pump cabinet ~5 m below ground level Pump pit 1.5 x 1.5 x 0.6 m3 at the bottom of the pool Pipes from pump cabinet to the pool, include: circu. pipe, water transfer pipe from/to main water station The pump cabinet may be not exactly as it was drawn in the plot because Yellow River realized the pumps have to be put several meters down the ground later.

5. Water are first purified from the main water system, then they are transferred to the water pool via pipe. When the pool is full, the circulation system start work because the water outlet is on one of the top corner of the pool ( other choice need work ) Essentially the pool in hall 4 is empty all the time. When we want to drain the experiment pool, we pump the water from hall 1/2/3 to hall 4. The water there do not need to be circulated, we just keep it off dust and bacteria. When we need water back from hall 4 to hall 1/2/3, the water are first purified in hall 4, then transferred to hall 1/2/3 via pipe. The consumption of water of water circulation is not much every day, so it is possible to use the seepage water. For ~1000 days of experiment running, this may save the same amount of money of the pre-treatment system.