building hydration=drying up/curing
concrete can leak when not compacted/vibrated upon filling..the reason they do that to let air out before drying so they wont leak, using vibration upon filling is common practice use when they build concrete wall/ground for water use.
there is a term in US called slab leak when water leaking out from under the ground over to slab flooring because it has nowhere to go but up.
i just hope its the extreme weather otherwise he will looking at ugly ground or possible sink hole somewhere in the long term.
