The exact nature of the impermeable ground layer of the lake is still unknown.

Usable in shallow impermeable grounds,and ropy ground i.e., near the plant roots.

A hydrostatic seal is created when the ice is so much higher around the lake that the equipotential surface dips down into impermeable ground.

Soil permeability (infiltration difficulty) and underlying rock type affect the runoff in a watershed; impermeable ground or exposed bedrock will lead to an increase in surface water runoff and therefore to more frequent streams.

SURFACE CAPPING (Encapsulation) Utilizes an impermeable ground cover to isolate the contaminants from the surface and redirect surface water percolation away from the contaminated soil.

The plains of Lombardy, formed by alluvial deposits, can be divided into the Alta - an upper, permeable ground zone in the north and a lower zone - the Bassa - dotted by the so-called line of fontanili, spring waters rising from impermeable ground.

Rather, it is sufficient to define future land use in broad-brush terms since the critical parameter is the proportion of impervious ground cover.

“It may seem like a bit of an oxymoron that garages could be green,” he said, “but decreasing the amount of impervious ground cover can be very beneficial in cities where runoff is the No. 1 pollutant.”