Aquifers of Long Island: Long Island is a tremendous source of ground water, and it is heavily utilized for domestic and agricultural wells. Withdrawals from this system account for about 25% of all ground-water usage in the Northeastern US. Much of the withdrawal is from the coastal plain sediments beneath the glacial deposits, but the lack of a confining layer across much of the island results in a continuous aquifer system. A lack of an extensive confining unit is common characteristic of sheet deposits, and makes them particularly vulnerable to contamination.
