1. 
   Aquitard
   Geological formation that may contain groundwater but is not capable of transmitting significant quantities of it under normal hydraulic gradients. May function as confining bed.
   Found op http://www.epa.gov/OCEPAterms/
   
   
2. 
   Aquitard
   A geological formation that prevents significant flow of water (e.g. clay).
   Found op http://www.encyclo.co.uk/visitor-contributions.php
   
   
3. 
   aquitard
   aquitard 1. A leaky confining bed that transmits water at a very slow rate to or from an adjacent aquifer. 2. A bed of low permeability adjacent to an aquifer. An aquitard may serve as a storage unit for groundwater, although it does not yield water readily.
   Found op http://www.wordinfo.info/words/index/info/view_unit/3692/
   
   

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