Impervious strata and formation definition
Impervious strata and formation means an underground or surface layer of soil or rock which will not allow water to pass through it at a rate permissible for subsurface disposal and having a percolation rate > 120 minutes per inch.
Impervious strata and formation means an underground or surface layer of soil or rock which will not allow water to pass through it at a rate permissible for subsurface disposal and having a percolation rate slower than one hundred twenty (120) minutes per inch.