The principal sources of ground water in the Sayreville area are the Old Bridge Sand and Farrington Sand Members of the Raritan Formation of Late Cretaceous age. These aquifers yielded about 32.3 mgd (million gallons per day) for public and industrial water supplies in 1958; about 24.5 mgd was withdrawn from the Old Bridge Sand Member.
Although the Old Bridge Sand Member is exposed to salt water in the Raritan Bay near South Amboy and in the South River near Old Bridge, there is no widespread salt-water encroachment problem in this aquifer. However, the intensity and distribution of pumping has been limited by the threat of such encroachment.
Widespread salt-water encroachment in the Farrington Sand Member has caused numerous wells to be abandoned; the greatest advance of salt water has been in the area south of Parlin. If not restricted, the encroachment of salt water threatens to render a considerable part of this aquifer unfit for use in most of the area south of Parlin.
The potential benefits of a proposed tidal dam on the South River are discussed. This dam would provide water for infiltration into the Old Bridge Sand Member and water for industrial and public supplies.
