Rock formations that are impermeable to groundwater water.

In hydrologic terms, a formation which contains water but cannot transmit it rapidly enough to furnish a significant supply to a well or spring.

rock formations impermeable to groundwater.

An impermeable geologic formation or stratum which will not hold or transmit fluid.

a body of rock that will slowly absorb water but will not transmit the water fast enough to supply a well or spring (from Dictionary of Geological Terms)

Most Pennsylvania aquifers may be categorized into confined

A formation which contains water but cannot transmit it rapidly enough to furnish a significant supply to a well or spring.

In hydrologic terms, a formation which contains water but cannot transmit it rapidly enough to furnish a significant supply to a well or spring.

a formation which, although porous and capable of absorbing water slowly, will not transmit water fast enough to furnish an appreciable supply for a well or a spring.

In hydrologic terms, a formation which contains water but cannot transmit it rapidly enough to furnish a significant supply to a well or spring.

An outdated term for a geologic layer of very low permeability located so that it forms an upper or lower boundary to a groundwater flow system. Aquitard or Confining Layer are preferred terms.