seepage

noun
  1. The slow escape of a liquid or gas through porous material or small holes. noun
    The seepage of water through the basement walls caused mold to grow.
    Engineers were concerned about the seepage of oil from the pipeline.
  2. The process by which a liquid or gas leaks through a porous substance or small holes. noun
    Seepage from the landfill was contaminating the nearby river.
    The seepage of chemicals into the soil posed a threat to the local ecosystem.