The Changing Pattern of 

Ground-Water Development 

on Long Island, New York

GEOLOGICAL SURVEY 

CIRCULAR 524

v^-> J

Nrr
The Changing Pattern of

Ground-Water Development

on Long Island, New York

By R. C. Heath, B. L. Foxworthy 

and Philip Cohen

Geological Survey Circular 524

Washington 1966
United States Department of the Interior

STEWART L. UDALL, Secretary

Geological Survey

William T. Pecora, Director

Free on application to the U.S. Geological Survey, Washington, D.C. 20242
CONTENTS

Page Page

Abstract___________________________ 1 Changes in ground-water develIntroduction______________________ 1 opment with time Continued

Geologic environment _______________ 1 Phase 3««_»____________»______ 5

Hydrologic system ________________ 3 Phase 4 ____________________ 5

Changes in ground-water Present areal differences in

development with time ____________ 4 ground-water development ________ 7

Phase 1 predevelopment Conclusion ______________________ 10

conditions __________________ 4 References cited __ ____ ____ __ 10

Phase 2 _________________________ 4

ILLUSTRATIONS

Page 

Figure 1. Map of Long Island and vicinity.______________________ _ _ _______ 2

2. Diagrammatic section showing general relationships of major rock units______ 2

3. Map showing generalized contours on the water table in 1961 ________________ 4

4 7. Diagrammatic sections showing generalized ground-water conditions during 

various phases of development:

4. Phase 1 predevelopment __________________________________ _____ 5

5. Phase 2 ______________________________________ ___ 6

6. Phase 3 _______________________________________ 7

7. Phase 4_____________________________________________ 8

8. Map showing water-development subareas in 1965 __________________________ 9

III
The Changing Pattern of Ground-Water Development on

Long Island, New York

By R. C. Heath, B. L. Foxworthy, and Philip Gotten

ABSTRACT

Ground-water development on Long Island has followed a 

pattern that has reflected changing population trends, attendant changes in the use and disposal of water, and the 

response of the hydrologic system to these changes. The 

historic pattern of development has ranged from individually 

owned shallow wells tapping glacial deposits to largecapacity public-supply wells tapping deep artesian aquifers. 

Sewage disposal has ranged from privately owned cesspools 

to modern large-capacity sewage-treatment plants discharging 

more than 70 mgd of water to the sea.

At present (1965), different parts of Long Island are characterized by different stages of ground-water development. In 

parts of Suffolk County in eastern Long Island, development 

is similar to the earliest historical stages. Westward toward 

New York City, ground-water development becomes more 

intensive and complex, and the attendant problems become 

more acute. The alleviation of present problems and those 

that arise in the future will require management decisions 

based on the soundest possible knowledge of the hydrologic system, including an understanding of the factors involved in the changing pattern of ground-water development 

on the island.

INTRODUCTION

Even before the severe drought that is now 

(1965) affecting the Northeastern United 

States, Long Island was well known among 

water specialists for its underground-water 

resource, mainly as a result of both the magnitude of the ground-water resource and the 

unique aspects of man's utilization of that 

resource. The current drought has focused 

increased attention upon the vast amount of 

ground water in storage on Long Island and 

upon the large quantity of water being pumped 

from the system. In 1963, for example, an 

average of about 380 mgd (million gallons per 

day) was pumped from Long Island wells; 

these wells tap a fresh ground-water reservoir that has an estimated storage capacity 

of 10 to 20 trillion gallons. Nearly all the

water pumped was for domestic and industrial use, and this pumpage probably represents one of the largest such uses of a single 

well-defined ground-water reservoir anywhere in the world.

The history of ground-water development 

on Long Island has been thoroughly documented, largely as a result of studies made 

by the U.S. Geological Survey in cooperation 

with the New York State Water Resources 

Commission and Nassau and Suffolk Counties. 

The water development has followed a general pattern which, although somewhat related to population density and local wastedisposal practices, has been controlled 

largely by the response of the hydrologic 

system to stresses that man has imposed 

upon the system. The purpose of this report 

is to summarize the highlights of the historical pattern of ground-water development on 

Long Island and to consider briefly the insight that the history of development affords 

regarding the future development and conservation of Long Island's most valuable 

natural resource.

GEOLOGIC ENVIRONMENT

Long Island (fig. l)has a land area of about 

1,400 square miles and is geographically a 

large detached segment of the Atlantic 

Coastal Plain. The island is underlain by 

crystalline bedrock, the uppermost surface 

of which ranges in altitude from about sea 

level at the northwest corner of the island to 

about 2,000 feet below sea level in the southeastern part of Suffolk County (fig. 2).

Thebedrock is overlain by a wedge-shaped 

mass of unconsolidated sedimentary deposits
THE CHANGING PATTERN OF GROUND-WATER DEVELOPMENT ON LONG ISLAND. NEW YORK

74° 73° 72"

41'

74"

NORTH

Glacial an 

undifferentiated 

deposits

Figure 1. Long Island and vicinity.

SOUTH

Not to scale

Figure 2. Diagrammatic section showing general relationships of the major rock units of the ground-water reservoir in Nassau County.
HYDROLOGIC SYSTEM

that attain a maximum thickness of about 

2,000 feet. These deposits constitute the 

ground-water reservoir of Long Island and 

can be divided into six major stratigraphic 

units, which differ in their geologic ages, 

mineral composition, and hydraulic properties. These units are, from oldest to youngest, (1) Lloyd Sand Member of the Raritan 

Formation, (2) clay member of the Raritan 

Formation, (3) Magothy Formation, (4) Jameco 

Gravel, (5) Gardiners Clay, and (6) glacial 

deposits. (Suter and others, 1949). The first 

three units listed are of Cretaceous age, and 

the last three are of Pleistocene age.

The Lloyd Sand Member of the Raritan 

Formation has a maximum thickness of about 

300feet andconsists mainly of fine to coarse 

sand and some gravel and interbedded clay. 

It forms the basal water-bearing unit of the 

ground-water reservoir. The clay member 

of the Raritan Formation is composed mainly 

of clay but locally contains considerable 

sand; it also has a maximum thickness of 

about 300 feet. Hydraulic ally, the clay member is a leaky confining layer for the Lloyd 

Sand Member retarding, but not preventing, 

vertical leakage of water to and from the 

Lloyd.

The Magothy Formation on Long Island is 

partly correlative with the Magothy Formation in New Jersey. It consists of complexly 

interbedded layers of sand, silt, and clay and 

some gravel in the lower part. The complexity of the interbedding and the character of 

fossils it contains suggest that the formation 

was mainly laid down under continental 

(flood-plain) conditions. The Magothy Formation is the thickest unit of the groundwater reservoir on Long Island, attaining a 

maximum thickness of about 1,000 feet. Its 

horizontal permeability differs widely from 

place to place and is considerably higher than 

its vertical permeability. It commonly yields 

more than 1,000 gpm (gallons per minute) per 

well. Water in the formation is largely under" 

artesian conditions.

Near the north and south shores of the 

island, the Magothy Formation locally is 

overlain by the Jameco Gravel. The maximum thickness of the Jameco is about 200 

feet. It consists mainly of medium to coarse 

sand, but locally contains abundant gravel 

and some silt and clay. The Jameco Gravel 

is moderately too highly permeable and 

yields as much as 1,500 gpm per well. Water

in the formation occurs under artesian conditions.

The Gardiners Clay is mainly restricted 

in extent to two moderately narrow bands 

that parallel the north and south shores, and 

it is commonly underlain by either the 

Jameco Gravel or the Magothy Formation.

The surface of Long Island is composed 

mostly of material deposited either directly 

by Pleistocene continental ice sheets or by 

melt water derived from the ice sheets. 

These glacial deposits consist mainly of 

sand and gravel outwash in the central and 

southern parts of the island, and mixed till 

and outwash atop and between the hills in the 

northern part of the island. The glacial outwash deposits are highly permeable and 

therefore -permit moderately rapid infiltration of precipitation.

HYDROLOGIC SYSTEM

The four major water-bearing units of the 

ground-water reservoir of Long Island are 

the glacial deposits, Jameco Gravel, Magothy 

Formation, and Lloyd Sand Member of the 

Raritan Formation (fig. 2). These four units 

contain mostly fresh ground water; however, 

locally they contain salty ground water or 

they are hydraulically connected with salty 

water of the ocean, sound, or bays. Under 

natural conditions recharge to the groundwater reservoir resulted entirely from the 

infiltration of precipitation, which is estimated to have averaged roughly 1 mgd per 

square mile (Swarzenski, 1963, p. 35). Most 

of the ground water moved laterally through 

the glacial deposits and discharged into 

streams or into bodies of salt water bordering the island without first reaching deeper 

water-bearing zones. Most of the remainder 

of the ground water moved downward through 

the glacial deposits into the Jameco Gravel 

or Magothy Formation, and from there part 

flowed laterally to the ocean and the remainder flowed downward through the clay 

member of the Raritan Formation into the 

Lloyd Sand Member. (See fig. 4.)

Estimates of ground-water discharge under natural conditions can be developed by 

extrapolation of data listed by Pluhowski and 

Kantrowitz (1964, p. 38-55) for the BabylonIslip area, a large and reasonably representative part of Long Island. Those data suggest
THE CHANGING PATTERN OF GROUND-WATER DEVELOPMENT ON LONG ISLAND, NEW YORK

74° 73° 72°

41°

10 15 20 MILES

Water-table contour

Contour interval 20 feet except 

locally, as shown. Datum is mean 

sea level

41"

74° 73° 72°

Figure 3. Generalized contours on the water table (the upper surface of the ground-water reservoir) in 1961.

that about 90 percent of the total recharge 

ultimately discharged from the glacial deposits (mainly by seepage to streams), and 

about 10 percent discharged by subsurface 

outflow from the Magothy Formation, the 

Jameco Gravel, and the Lloyd Sand.

The water table on Long Island (fig. 3) and 

also the piezometric (pressure) surfaces of 

the underlying artesian aquifers (which have 

about the same general shape as the water 

table) form elongate mounds following roughly the configuration of the land surface. 

Two prominent highs characterize the water 

table one centered in Nassau County and 

one centered in Suffolk County. Northwestern 

Queens County also has a small high in the 

water table. Other notable features are the 

cones of depression that extend below sea 

level in Kings and Queens Counties; these 

cones are in areas of past or current local 

overdevelopment of ground water.

CHANGES IN GROUND-WATER DEVELOPMENT 

WITH TIME

PHASE 1 PREDEVELOPMENT CONDITIONS

Ground-water development on Long Island 

has progressed and is progessing through 

several distinct phases. Under natural or 

predevelopment conditions (fig. 4), the hydrologic system was in overall equilibrium

and long-term average ground-water recharge and discharge were equal. The general positions of the subsurface interfaces 

between fresh and salty water in each of the 

previously described geologic units were 

stable, reflecting the overall hydrologic balance. The interfaces were virtually at the 

coasts in the glacial deposits and were offshore in the underlying units.

PHASE Z

In the initial stage of development (fig. 5), 

which began with the arrival of the first 

European settlers, virtually every house had 

a shallow well drawing water from the glacial deposits and a cesspool returning waste 

water to the same deposits. As the population increased, individual wells were abandoned and public-supply wells were installed 

in the glacial deposits. The individual cesspools, however, were retained and little water 

was lost from the system during use. Although a considerable amount of ground water 

was being withdrawn, practically all of it was 

returned to the same aquifer from which it 

was removed. In general, therefore, the 

system remained in balance, and the positions of the interfaces between fresh and salt 

water remained practically unchanged. However, this cycle of ground-water development and waste-water disposal resulted in 

the pollution of the shallow ground water in 

the vicinity of the cesspools.
CHANGES IN GROUND-WATER DEVELOPMENT WITH TIME 

LONG ISLAND

NORTH .S-g SOUTH

ATLANTIC 

BA Y OCEAN

EXPLANATION

Salt water of ocean, 

sound, and bay

Unconsolidated rock materials 

containing fresh water

Unconsolidated rock materials 

containing salty water General movement of fresh water

Figure 4. Diagrammatic section showing predevelopment (phase 1) generalized ground-water conditions. Contacts between rock units are as

shown in figure 2.

PHASE 3

In time, as the cesspool pollution spread, 

some shallow public-supply wells had to be 

abandoned and these were replaced with 

deeper public-supply wells, most of which 

tapped the Jameco Gravel and the Magothy 

Formation. Supply wells were also constructed in the deeper units at places where 

the glacial deposits contained water with objectionable amounts of dissolved iron or 

other troublesome natural constituents. Most 

of the water withdrawn from the deeper units 

was returned to the shallower glacial deposits by means of cesspools, and subsequently discharged to the sea by subsurface 

outflow or by seepage to streams (fig. 6).

As a result of the withdrawal of water 

from the Magothy Formation and the Jameco 

Gravel, and the concurrent decrease in hydraulic heads in these units, the downward 

movement of ground water from the overlying glacial deposits locally was increased. 

However, the increased downward movement 

only partially compensated for the withdrawals of water from the Magothy and 

Jameco deposits. Locally, a hydraulic imbalance developed in the Magothy and Jameco 

deposits and caused a decrease in the amount 

of fresh ground water in storage and a landward movement of salty water.

PHASE 4

The next major phase in the development 

of ground water on Long Island (fig. 7) was 

the introduction of large-scale sewer systems notably in that portion of Long Island 

that is part of New York City (Kings and 

 Queens Counties), Most of the pumped ground 

water that previously had been returned to
THE CHANGING PATTERN OF GROUND-WATER DEVELOPMENT ON LONG ISLAND, NEW YORK

LONG ISLAND

NORTH SOUTH

EXPLANATION

Well discharging fresh water

General movement of fresh water

Salt water of ocean, 

sound, and bay

Unconsolidated rock materials

Cesspool receiving waste water

Unconsolidated rock materials 

containing fresh water Contamination from wastes

Figure 5. Diagrammatic section showing generalized ground-water conditions during phase 2 of ground-water development (shallow supply 

wells and waste disposal through cesspools). Contacts between rock units are shown in figure 2.

the ground-water reservoir by means of 

cesspools was thereafter discharged to the 

sea through the sewers. Whereas the net 

draft on the ground-water system during the 

preceding phases of development was negligible, virtually all the ground water diverted 

to sewers during phase 4 represented a permanent loss from the system. The newly 

imposed stress on the ground-water system 

locally resulted in a rapid landward encroachment of salty water into the previously 

fresh ground-water reservoir. The most 

dramatic example occurred during the 1930's 

in Kings County (the Borough of Brooklyn), 

which by that time had been completely sewered for many years. In 1936, decreased 

natural recharge owing to urbanization and 

increased ground-water withdrawals, which 

during the previous few years averaged more 

than 75 mgd, caused ground-water levels in

Brooklyn locally to decline to as much as 35 

feet below sea level (Lusczynski, 1952, pis. 

1 and 2). This local overdevelopment caused 

contamination of large parts of the groundwater reservoir in that area from sea-water 

encroachment.

In 1947 virtually all pumping for public 

supply in Kings County was discontinued and 

the Borough was thereafter supplied with 

water from the New York City municipalsupply system, which utilizes surface-water 

reservoirs in upstate New York. A notable 

exception was ground-water withdrawal for 

air-conditioning use. Such usage was permitted, however, only under the condition 

that the water was returned to the groundwater reservoir by means of injection wells 

(locally referred to as "diffusion" wells).
PRESENT AREAL DIFFERENCES IN GROUND-WATER DEVELOPMENT

LONG ISLAND

NORTH SOUTH

Well discharging fresh water

EXPLANATION

Salt water of ocean, 

sound, and bay

Unconsolidated rock materials

Cesspool receiving waste water General movement of fresh water

Unconsolidated rock materials 

containing fresh water Contamination from wastes

Figure 6. Diagrammatic section showing generalized ground-water conditions during phase 3 of ground-water development (deep supply 

wells and waste disposal through cesspools). Contacts between rock units are as shown in figure 2.

PRESENT AREAL DIFFERENCES IN GROUNDWATER DEVELOPMENT

The present pattern of ground-water development on Long Island affords an excellent opportunity to observe and evaluate the 

historic trend of that development, because 

all the major phases of development described herein, except the predevelopment 

phase, can be observed now in different subareas of the island (fig. 8). Moreover, once 

the transitory status of present development 

in each subarea is recognized in relation to 

the pattern of historical trends, it becomes 

possible to predict and perhaps forestall 

some of the undesirable aspects of those 

trends.

Subarea A (fig. 8) includes roughly the 

eastern two-thirds of Suffolk County. Except

for several small communities, the subarea 

is largely rural and has the lowest population 

density on Long Island. On the whole, the 

subarea can be characterized as being in 

phase 2 of ground-water development (fig. 

5) that is, most of the wells in the subarea 

tap the shallow glacial deposits and supply 

water to single-family dwellings. The bulk 

of this water is returned to the glacial deposits through individually owned cesspools, 

and in overall aspect the ground-water system is still in hydraulic balance.

Subarea B, in central Suffolk County, is 

experiencing the impact of the suburban expansion associated with the entire New York 

City metropolitan area. Farms and woodlands are giving way to housing developments, and most of the pumpage in the subarea is now from large-capacity publicsupply wells that tap the glacial deposits.
THE CHANGING PATTERN OF GROUND-WATER DEVELOPMENT OF LONG ISLAND. NEW YORK

LONG ISLAND

NORTH SOUTH

"" 5 ATLANTIC 

 BA Y fi^L OCEAN

Salt water of ocean, 

sound, and bay

Unconsolidated rock materials

Well discharging fresh water General movement of fresh water

Unconsolidated rock materials 

containing fresh water Residual contamination from wastes

P

Movement of waste water

Figure 7. Diagrammatic section showing generalized ground-water conditions during phase 4 of ground-water development (deep supply 

wells and waste disposal through sewers to adjacent salt-water bodies). Contacts between rock units are as shown in figure 2. '

However, most of the sewage disposal is still 

through individually owned cesspools. Thus, 

the area is in a transition between phase 2 

and phase 3 of development. Cesspool pollution still is not widespread, but is substantial enough to be of concern to local 

government agencies. Accordingly, plans are 

currently (1965) being made to construct 

sewers in the area and to gradually replace 

the wells that tap the glacial deposits with 

wells that will tap the Magothy Formation.

Subarea C includes the westernmost part 

of Suffolk County and the eastern two-thirds 

of Nassau County. Mainly because it is 

closer to New York City, this subarea was 

subjected to intensive suburban development 

earlier than was subarea B. Therefore, the 

population density and, accordingly, the water requirements in subarea C are substantially greater than in subarea B. Virtually the 

entire water supply for subarea C is obtained 

from large-capacity public-supply wells. The 

part of the subarea that is in western Suffolk 

County obtains most of its water supply from 

public-supply wells, of which about half tap 

the glacial deposits and most of the remainder 

tap the Magothy Formation. In the part of the 

subarea that is in Nassau County, most of the 

public-supply wells tap the Magothy Formation,

Except for a few communities along the 

coast, most of subarea C is not sewered; 

practically all the domestic sewage is disposed of through individually owned cesspools. 

Thus, on the whole the subarea is in phase 3 

'of development (fig. 6). The system locally 

is out of balance owing to this development; 

however, substantial widespread salt-water
PRESENT AREAL DIFFERENCES IN GROUND-WATER DEVELOPMENT

encroachment has not yet occurred. Plans 

are being made to install sewers throughout 

the subarea.

Subareas D and E, which include parts of 

western Nassau and southeastern Queens 

Counties, are moderately to highly urbanized

and are almost completely sewered. Practically the entire water supply for these subareas is derived from wells tapping the 

Magothy Formation, Jameco Gravel, and the 

Lloyd Sand Member of the Raritan Formation. 

Thus, these subareas are mainly in phase 4 

of development and are characterized by a

73* 72°

41'

10 15 20 MILES

41°

74"

Subarea

73*

EXPLANATION 

Characteristics

72°

A... Phase 2 of development. Pumpage mainly from shallow privately owned wells. Waste 

water returned to shallow glacial deposits through cesspools; local contamination of 

glacial deposits by cesspool effluent. System virtually in balance; positions of saltwater fronts unchanged.

B Transition between phase 2 and 3. Pumpage from privately owned and public-supply

wells. Waste water returned to shallow glacial deposits by way of cesspools; areas of 

cesspool-effluent contamination spreading. System virtually in balance.

C... Phase 3 of development. Pumpage mainly from deep public-supply wells; waste water 

returned to shallow glacial deposits by way of cesspools. System locally out of balance, causing local salt-water intrusion.

D...Phase 4 of development. Pumpage almost entirely from deep public-supply wells; waste 

water discharged to the sea by way of sewers. System out of balance; salty water 

actively moving landward.

E___ Phase 4 of development. Pumpage almost entirely from deep public-supply wells; waste 

water discharged to the sea by way of sewers. System out of balance; may be subject 

to salt-water intrusion in the future.

F_ Very little ground-water development. Water supply derived from New York City

municipal-supply system; waste water discharged to the sea by way of sewers. System in balance.

G... Very little ground-water development. Water supply derived from New York City

municipal-supply system; waste water discharged to the sea by way of sewers. Large 

areas contain salty ground water owing to former intensive ground-water development and related salt-water intrusion.

Figure 8. Water-development subareas in 1965.
10 THE CHANGING PATTERN OF GROUND-WATER DEVELOPMENT OF LONG ISLAND, NEW YORK

hydrologic imbalance (fig. 7). "The imbalance, which is accentuated because more 

than 70 mgd of water derived from the 

ground-water reservoir of these subareas 

currently is being discharged to the sea by 

way of sewage-treatment plants, is mostly 

clearly manifested in subarea D, where salty 

water is moving landward (Lusczynski and 

Swarzenski, 1960; Perlmutter and Geraghty, 

1963). If the present trend continues, subarea D (the area of active salt-water encroachment) probably will expand at the expense of subarea E.

Subarea F, in northeastern Queens County, 

receives nearly its entire water supply from 

the New York City municipal-supply system. 

The subarea is sewered; however, because 

ground-water pumpage is negligible, the 

ground-water system is largely in balance.

Subarea G is the most highly urbanized and 

receives virtually all its water from the New 

York City municipal system. The entire subarea is sewered. As previously noted, large 

areas in Kings County were invaded by salty 

water because of substantial overdevelopment 

and the resulting decline in ground-water 

levels. Similarly, salty water had invaded the 

ground-water reservoir in parts of western 

Queens County. Water levels in Kings County 

have recovered appreciably since the mid 

1940*s, when the consumptive ground-water 

uses were drastically reduced. Presumably, 

the salty water is retreating seaward and is 

being diluted by recharge derived from precipitation, but precise data regarding these 

changes are lacking.

CONCLUSION

Ground water probably will continue to be 

the major source of water for most of Long 

Island (except for Kings and Queens Counties) 

for at least the next several decades. Moreover, if the present trends continue, the 

ground-water resources of the island probably will continue to be depleted perhaps at 

an accelerated rate. The historic trends of 

ground-water development and the present 

status of development strongly suggest that 

such depletion will in time cause salt-water 

contamination of larger and larger parts of 

the ground-water reservoir. Moreover, the 

areas in which such contamination occurs, in 

addition to extending inward from the coasts, 

probably will also extend farther and farther 

eastward as the population continues to expand in that direction.

Several alternative methods of conserving 

and augmenting the ground-water resources

of Long Island are currently being considered. These include, among others, desalting 

of sea water with the use of atomic energy, 

artificial recharge, and the reclamation of 

water from sewage. The consequences of 

such possible measures are highly significant inasmuch as the future well-being of 

several million people is at stake. However, 

even with the most promising of conservation methods, wise management will be required to gain the fullest use from the available fresh-water supply while also preventing undue hardships resulting from local 

overdevelopment of the ground-water reservoir. Fully effective management requires:

1. Recognition of the unity of the hydrologic system of Long Island.

2. The best obtainable scientific information about the system and how it functions.

3. Sound evaluation of the various alternative methods of water development and conservation, guided by available scientific information including the hydrologic consequences of the historic and present-day 

changing pattern of ground-water development on Long Island.

REFERENCES CITED

Lusczynski, N. J., 1952, The recovery of 

ground-water levels in Brooklyn, New York 

f.rom 1947 to 1950: U.S. Geol. SurveyCirc. 

167, 29 p.

Lusczynski, N. J., and Swarzenski, W. V., 1960, 

Position of the salt-water body in the 

Magothy(?) Formation in the Cedar hurstWoodmere area of southwestern Nassau 

County: N.Y. Econ. Geology, v. 55, no. 8, 

p. 1739-1750.

Perlmutter, N. M., and Geraghty, J. J., 1963, 

Geology and ground-water conditions in 

southern Nassau and southeastern Queens 

Counties, Long Island, New York: U.S. Geol, 

Survey Water-Supply Paper 1613 A, 205 p.

Pluhowski, E. J., and Kantrowitz, I. H., 1964, 

Hydrology of the Babylon-Isliparea, Suffolk 

County, Long Island, New York: U.S. Geol. 

Survey Water-Supply Paper 1768, 119 p.

Suter, Russell, de Laguna, Wallace, and PeriMutter, N. M., 1949, Mapping of geologic 

formations and aquifers on Long Island, 

New York: New York State Power and Control Comm. Bull. GW-18, 212 p.

Swarzenski, W. V., 1963, Hydrology of northwestern Nassau and northeastern Queens 

Counties, Long Island, New York: U.S. Geol. 

Survey Water-Supply Paper 1657, 90 p.