Because there is a pump functioning in the "break tank".
So potential some noise when the pump running time.

It is not about leaking issue, but potential some noise.

There is no "danger" to own a unit adjacent or near the break tank, but potential some noise.
Pump leaking won't result your unit being "flooded".
So don't worry.

The pump is not supplying the water to unit around, but to pump the water to the roof tank.

How well the noise issue being insulated, or how well the pump (quiet) or noisy in function, then it depended on the pump quality and installation issue itself.
This is hard to know until the building is completed and the pump is functioning.

Then it depended on the quality of the pump.

The door for break tank area generally is not "sound insulated" like KTV room.

Having said that, it all depended, some pump functioning fairly quiet, while some like "dinosaur roar".

Also there may be some "water sound/noise" when the tank being filled time especially the tank is running very low level time. But generally should be very minimal as compared to pump sound.

Among them, if really want to choose, the upper unit may have the least noise as compared to lower or adjacent unit.
Just like you will hear upstair people jumping up and down, knocking sound etc. but you won't hear those sound from lower unit.

The ideal unit is always far away from break tank, far away from lift lobby, far away from rubbish collection corner.