Altitude of the top of the Matawan Group-Magothy Formation, Suffolk County, Long Island, New York

The Magothy aquifer, with its irregular surface and deeply eroded buried valleys, has become the major source of fresh water in most of Suffolk Country. With the availability of recent data from deep wells and test holes, refinement of the surface-altitude contours has been possible and resulted in substantial revision in some areas. This 1-sheet map delineates the surface altitude of the Magothy aquifer (Matawan Group-Magothy Formation) and includes a brief text and bibliography.