210 CONSERVATION OF GROUND WATER 



In the northernmost 7 miles of the proposed lock canal, 

 the maintenance of the upper level at 10 feet above mean 

 low water would create a shallow pool. Where this pool 

 covers the intake areas of important aquifers, it would fur- 

 nish substantial recharge to them, and the water supplies 

 for such cities as Parlin and Perth Amboy might gain some 

 quantitative advantage from the canal. However, wells re- 

 charged by canal infiltration would yield water containing 

 about the same concentration of salt as the canal water (fore- 

 cast 30 parts per million of salt at Parlin). Farther south, 

 the Duhernal wells (see page 128) pump water for chemical 

 processes where the tolerance is in the order of 10 parts per 

 million of chloride. It has been estimated that after con- 

 struction the canal would furnish about three-fourths of the 

 supply to the Duhernal wells, and the permissible limit of 

 salt content in the canal water would therefore be about 

 20 parts per million of salt. f 



Farther south the canal would cause a material lowering 

 of the water table, and numerous domestic and farmstead 

 wells would need to be deepened. A less immediate but ulti- 

 mately more important effect would be the lowering of water 

 levels in artesian wells south and east of the canal route as 

 far as the Atlantic Coast. These aquifers are believed to 

 contain salt water held in balance by the artesian head of 

 the fresh water in them. The lowering of artesian head by 

 construction of the canal would probably permit the salt 

 water to advance inland over a band several miles in width, 

 and wells within this band would yield water of poorer 

 quality. Available information as to the position of salt water 

 in the aquifers is meager, but the water supplies most likely 

 to be affected are those along the Atlantic Coast from Asbury 

 Park to Sandy Hook, and along the southeast shore of Rari- 

 tan Bay. 



To summarize, the proposed lock canal of the Intracoastal 

 waterway in New Jersey would probably decrease the availa- 

 ble ground-water supplies in some areas and augment them 

 in others; wells in some areas would ultimately pump water 



