from the ground-water drainage divide near the center of the island. About 

 half of the ground-water discharge is subsurface outflow into Long Island 

 Sound and the Atlantic Ocean, the rest is discharged to streams and springs 

 or evapotranspi red from the upper part of the saturated zone. Figure 2 shows 

 the pattern of water circulation on Long Island under natural conditions. 



Fresh ground water 



Salty ground water 



Figure 2. Block diagram illustrating ground-water movement and discharge on 

 Long Island, New York under natural conditions. After Cohen and others 

 (1968 pi. kF). 



The land on the north shore of Long Island Sound is underlain by 

 bedrock at relatively shallow depth. The surface is di scont i nuously covered 

 by unconsolidated deposits composed of sand, gravel, silt and clay. Major 

 surface-water and ground-water drainage divides are coincident and the area 

 hydrological ly consists of a number of separate ground-water reservoirs each 

 drained by a perennial stream and extending from one drainage divide to another. 

 The amount of water stored in and moving through the saturated zone varies in 

 each basin because of differences in size and type and distribution of sub- 

 surface materials. 



