The Three Major Long Island Aquifers: Nassau and Suffolk counties obtain their drinking water from three major aquifers underlying Long Island which constitute a sole source aquifer. The aquifers are, from the shallowest to the deepest, the Upper Glacial, the Magothy and the Lloyd aquifers.
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How many different aquifers are present in Long Island name them?
It comprises three major aquifers, an Upper Glacial aquifer at the top, the Magothy aquifer in the middle and a deep less accessible Lloyd aquifer lying just above the Paleozoic metamorphic basement rocks. There are two major confining units.
Where are the aquifers on Long Island?
Long Island’s aquifer system is comprised of several freshwater zones, or “aquifers”, generally ranging in increasing depth from the upper glacial, North Shore, Jameco, Magothy, and finally the Lloyd aquifer.
What is the name of the major aquifer?
The Ogallala, also known as the High Plains Aquifer, is one of the largest underground freshwater sources in the world. It underlies an estimated 174,000 square miles of the Central Plains and holds as much water as Lake Huron.
How many groundwater wells are active on Long Island?
There are over 4,300 groundwater sites on Long Island that can be selected which have at least one water level measurement (depth to water measurement).
What are the layers of an aquifer?
An aquifer is a body of rock and/or sediment that holds groundwater.There are two general types of aquifers: confined and unconfined. Confined aquifers have a layer of impenetrable rock or clay above them, while unconfined aquifers lie below a permeable layer of soil.
What is the Lloyd aquifer?
The Lloyd Aquifer is the purest, deepest and most limited aquifer serving Long Island. Long Beach relies solely on water pumped from the Lloyd, to meet the needs of 34,000 residents.
Where is the Lloyd aquifer?
Long Island
The Lloyd aquifer (Lloyd Sand Member of the Raritan Formation), is the oldest of the Cretaceous age formations on Long Island. It extends from central Kings, northwestern Queens and Nassau, and northeastern Suffolk Counties to the east and south (fig. 3).
How deep is the aquifer on Long Island?
approximately 2000 feet
The total depth of the Long Island Aquifer System is shallowest on the north shore (approximately 600 feet) and deepest along the south shore (approximately 2000 feet).
Which of the two aquifers on Long Island would be more prone to contamination?
Unconfined aquifers generally are much more vulnerable to contamination than confined aquifers. For a well in a confined aquifer, the farther the well is from the unconfined area, the less vulnerable it is to contamination.
Do aquifers have names?
Rock-stratigraphic names may be used for aquifer names in studies that cover one State or parts of a State and an adjacent State.In some areas, aquifers have been named for rock-stratigraphic units but consist of parts of the units only.
What are the three types of aquifers?
Figure 2 is a simple cartoon showing three different types of aquifers: confined, unconfined, and perched. Recharge zones are typically at higher altitudes but can occur wherever water enters an aquifer, such as from rain, snowmelt, river and reservoir leakage, or from irrigation.
What is the name of the aquifer found under Kansas?
Ogallala Aquifer
The Ogallala Aquifer, the vast underground reservoir that gives life to these fields, is disappearing. In some places, the groundwater is already gone. This is the breadbasket of America—the region that supplies at least one fifth of the total annual U.S. agricultural harvest.
Is the Lloyd aquifer confined or unconfined?
The Lloyd aquifer is the only true confined aquifer. It is separated from the Magothy by a thick clay layer known as the Raritan Clay.
Is Long Island water contaminated?
“Western Nassau County is up to 17.5 parts per billion when the drinking water standard is currently 1. Also, it has all three chemicals. So unfortunately they are getting the trifecta of water contamination. “We object to the public being told that contamination in our drinking water is safe,” she continued.
What is Raritan clay?
The Raritan Formation consists of an upper clay member and a lower sand member (Lloyd Sand). The clay member is a confining unit and the Lloyd Sand is a confined aquifer.Under Long Island the clay member has a maximum thickness of 300 ft and the Lloyd Sand has a maximum thickness of 500 ft.
What is the base of an aquifer?
To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock.This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface.
What are impermeable layers?
IMPERMEABLE LAYER: A portion of an aquifer that contains rock material that does not allow water to penetrate; often forms the base of unconfined aquifers and the boundaries for confined aquifers.
What are aquifers and its types?
A groundwater aquifer is said to be unconfined when its upper surface (water table) is open to the atmosphere through permeable material. As opposed to a confined aquifer, the water table in an unconfined aquifer system has no overlying impervious rock layer to separate it from the atmosphere.
What Moraine is known as the backbone of Long Island?
Ronkonkoma moraine
The more southerly moraine, known as the Ronkonkoma moraine, forms the “backbone” of Long Island; it runs primarily through the very center of Long Island, roughly coinciding with the length of the Long Island Expressway. The land to the south of this moraine to the South Shore is the outwash plain of the last glacier.
Is the Magothy aquifer confined?
The Upper Glacial and Magothy Aquifers are under water-table (unconfined) conditions, whereas the Lloyd Aquifer is under artesian (confined) conditions in most locations.The concurrent use of the aquifer system for both water supply and waste disposal is unsustainable.
