As nouns the difference between seepage and spillage
is that seepage is the process by which a liquid leaks through a porous substance; the process of seeping while spillage is that which has been spilled.
seepage
English
Noun
(
en noun)
the process by which a liquid leaks through a porous substance; the process of seeping
water that seeped or oozed through a porous soil
See also
* seepage bed