No hydraulics in this area of the belly fairing.The fwd drain mast is located there.But for fluids coming from the fwd galleys via the GWDU (galley waste deposal unit,kind of second sink for all kinds of deposal)the correct storage are the waste tanks...
Outboard via 2 drain masts: Lavatory washbasins,galley sinks and showers when installed.
Collected in waste tanks:Toilets and GWDUs.
Last option for the dirty fuselage:Spillage in fwd cargo,drain overboard