biomat

bio- +‎ mat

biomat (plural biomats)

1. (subsoil hydraulics) A clogging layer of typically densely packed decaying organic matter which impedes the downward flow of water.
   • 1999, Bruce C. Alleman, ‎Andrea Leeson, Natural attenuation of chlorinated solvents, petroleum hydrocarbons, and other organic compounds, Volume 5

     This may be an artifact of the aerobic conditions used which would not favor the growth of any anaerobic bacteria that may exist in the low oxygen regions within the biomat.

2. A restrictive layer that develops beneath the distribution lines of the soil absorption system of septic tanks at the gravel-soil or bed-soil interface.

• aimbot