Long Island Expwy

Middle Country Rd

Sunrise Hwy

Will ai m F ol yd Pkwy

Middle Country Rd

Long Island Expwy

Sunrise Hwy

West Main St

Main Rd

Main Rd

Main Rd

Sunrise Hwy

Montauk Highway

Montauk Hwy

Montauk Hwy

Montauk Hwy

Medford Rd

Patchogue - Yaphank Rd

Nesconset Rd

Patchogue - Port Jefferson Rd

Main St

Rocky Po ni t Rd

Sound Ave

Sound Avenue

Parker Road

Nugent Dr

Moriches - Riverhead Rd

Roanoke Ave

East Main St

Cross River Dr

Riverhead - Quogue Rd

Sound Ave

Montauk Hwy

Port Jefferson - West Hampton Rd

O dl Riverhead Rd

Lewis Rd

Montauk Hwy

Riverhead - Hampton Bays Rd

Montauk Hwy

(Hill St)

Ferry Rd

South Ferry Rd

Hampton St

Sag Harbor Tpke

Main St

William

Floyd Pkwy

Yaphank -

M di d el Island Rd

Gowanus Expwy

Belt Pkwy

(Shore Pkwy)

Belt Pkwy

(Shore Pkwy)

Belt Pkwy

(Shore Pkwy)

Belt Pkwy

Van Wyck Expwy

Cross Island Pkwy Sunrise Hwy

Southern State Pkwy

Brooklyn - Queens Expressway

Long Island Expwy

Queens Blvd

Grand Central Pkwy

Whitestone Expwy

Van Wyck Expwy

Linden Blvd

Clearview Expwy

Cross Island Pkwy

Jericho Tpke

Long Island Expwy

Meadowbrook State Pkwy

Jericho Turnpike

Jericho Tpke

Long Island Expwy

Wantagh State Pkwy

Seaford - Oyster Bay Expwy

Northern State Pkwy

Loop Pkwy

Meadowbrook State Pkwy

Sunrise Hwy

Ocean Pkwy

Wantagh State Pkwy

Southern State Pkwy

Southern State Pkwy

Sunrise Hwy

Ocean Pkwy

Robert Moses Twin Causeway

Jericho Tpke

Northern State Pkwy

Long Island Expwy

Sunken Meadow State Pkwy

Sagt ki os State Parkway

Southern State Pkwy

Heckscher State Pkwy

Long Island Expwy

Middle Country Rd

Ocean Pkwy

Kings Highway Flatbush Ave

Prospect Ave

Flatbush Avenue

Broadway

Eastern Parkway

Bay Pkwy

Northern Blvd

Woodhaven Blvd

Union Tpke

Myrtle Ave

Myrtle Ave

Cross Bay Blvd

Rockaway Blvd

Linden Blvd

Hillside Ave Rockaway Blvd

Merrick Blvd

Utop ai Pkwy

Northern Blvd

Northern Blvd

M di d el Neck

Franklin Ave

Hempstead Tpke

Merrick Rd

Lido Blvd

Peninsula Blvd

Merrick Rd

Newbr di ge Rd

Hempstead Tpke

Port Washington Blvd

Hicksville Rd

Northern Blvd

Jer ci ho - Oyster Bay Rd

Cedar Swamp Rd

Montauk Hwy

New York Ave

Deer Park Ave

New York Ave

Northern Blvd

Northern Blvd

Elwood Rd

Wheeler Rd

Veterans Memorial Hwy

Hauppauge Rd

North Country Rd

Nesconset - Port Jefferson Hwy

Stony Brook Rd

Car el ton Ave

Smithtown Ave

Montauk Hwy

Sunrise Hwy

Veterans Memorial Hw

No

y

rthern State Pkwy

Jamaica Ave

Hillside Ave

Union Tpke

Grand Central Pkw

Lon

y

g Island Expwy

Rd

ATLANTIC OCEAN

LOWER

NEW YORK

BAY

UPPER

NEW YORK

BAY

SMITHTOWN

BAY

JAMAICA

BAY

EAST

RIVER

NORTHPORT

BAY

HUNTINGTON

BAY OYSTER

BAY

HARBOR

MANHASSET 

BAY

LITTLE

NECK

BAY

COLD

SPRING

HARBOR

HEMPSTEAD 

HARBOR

FLUSHING

BAY

HUDSON

RIVER

EAST

BAY

LONG

ISLAND SOUND

NICOLL

BAY

LONG ISLAND SOUND

ATLANTIC OCEAN

BLOCK ISLAND 

SOUND

GARDINERS

BAY

GREAT

PECONIC

BAY

NAPEAGUE

BAY

LITTLE

PECONIC

BAY

NOYACK

BAY

MORICHES

BAY

SHINNECOCK

BAY

NORTHWEST

HARBOR

THREE

 MILE 

HARBOR

ORIENT

HARBOR

SOUTHOLD

BAY

HOG

NECK

BAY

CUTCHOGUE

HARBOR

MECOX

BAY

FLANDERS

BAY

TIANA

BAY

BELLPORT 

BAY PATCHOGUE 

BAY

GREAT SOUTH BAY

SOUTH

OYSTER

BAY

SHELTER ISLAND SOUND

NEW YORK

NEW YORK

COUNTY

HUDSON

COUNTY

BRONX COUNTY

RICHMOND

COUNTY

WESTCHESTER

COUNTY

KINGS

COUNTY

QUEENS

COUNTY

NEW YORK

NEW JERSEY

NEW YORK

NEW JERSEY

NEW YORK

NEW YORK COUNTY

SUFFOLK COUNTY

KINGS COUNTY

NEW YORK COUNTY

QUEENS COUNTY

BRONX COUNTY

QUEENS COUNTY

NASSAU COUNTY

BRONX COUNTY

WESTCHESTER COUNTY

BRONX COUNTY

WESTCHESTER COUNTY

NASSAU COUNTY

CONNECTICUT

NEW YORK

FAIRFIELD COUNTY

NASSAU COUNTY

CONNECTICUT

SUFFOLK COUNTY

NASSAU COUNTY

SUFFOLK COUNTY

NASSAU COUNTY SUFFOLK COUNTY

NASSAU COUNTY

NASSAU COUNTY

QUEENS COUNTY

QUEENS COUNTY

NASSAU COUNTY

QUEENS COUNTY

KINGS COUNTY

KINGS COUNTY

QUEENS COUNTY

NEW YORK COUNTY

HUDSON COUNTY RICHMOND COUNTY KINGS COUNTY

NASSAU 

COUNTY

SUFFOLK COUNTY

CONNECTICUT

NEW HAVEN COUNTY

NEW JERSEY

NEW YORK

NEW JERSEY

NEW YORK

-74° -73°30' -73° -72°30' -72°

-74° -73°30' -73° -72°30' -72°

40°50'

40°40'

40°30'

41°10'

41°

40°50'

10 0 10 MILES

10 0 10 KILOMETERS

SCALE=1:125,000

NEW YORK

CONNECTICUT

NEW JERSEY

Long Island

ATLANTIC OCEAN

20 0 20 KILOMETERS

20 0 20 MILES

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Prepared in cooperation with the

NASSAU COUNTY DEPARTMENT OF PUBLIC WORKS

NEW YORK CITY DEPARTMENT OF ENVIRONMENTAL PROTECTION

NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION

SUFFOLK COUNTY DEPARTMENT OF HEALTH SERVICES

SUFFOLK COUNTY WATER AUTHORITY

TOWN OF NORTH HEMPSTEAD

TOWN OF SHELTER ISLAND

AND THE U.S. ENVIRONMENTAL PROTECTION AGENCY

Base from U.S. Geological Survey digital data 1:100,000 series

Lambert Conformal Conic projection

Standard parallels 40° 40' N and 41° 2' N, central meridian 74° 00' W

North American Datum of 1983 Water-Table and Potentiometric-Surface Altitudes in the Upper Glacial, Magothy, and Lloyd Aquifers beneath Long Island, New York, April–May 2010

By

Jack Monti, Jr., Michael Como, and Ronald Busciolano

2013

For additional information write to:

Director, U.S. Geological Survey, 2045 Route 112, Coram, NY 11727

Copies of this report are available on-line at http://ny.water.usgs.gov or can be purchased from:

U.S. Geological Survey, Branch of Information Services, Box 25286, Denver, CO 80225-0286

Suggested citation: Monti, Jack, Jr., Como, Michael, and Busciolano, Ronald, 2013, Water-table and potentiometricsurface altitudes in the Upper Glacial, Magothy, and Lloyd aquifers beneath Long Island, New York, April-May 2010: 

U.S. Geological Survey Scientific Investigations Map 3270, 4 sh., http://dx.doi.org/10.3133/sim3270.

Hydrology by Jack Monti, Jr.

ISSN 2329-132X (online)

http://dx.doi.org/10.3133/sim3270

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80

80

S89534

28.00

N11579

15.00

S73998

7.25

S59992

7.24

S60123

9.77

S82939

4.85

S15622

43.30

S94489

19.20

S76673

65.80

S84806

27.10

S95965

78.70

S74284

75.10

S79408

7.22

N12152

4.64

N3867

6.05

N2790

4.93

N6510

N3862 6.14

4.41

N6850

6.12 N11109

0.44

Q3589

7.81

Q3112

9.13

Q3109

4.68

Q3110

6.47

K3407

1.33

K3414

5.56

S105710

11.92

S105711

13.89

S71576

12.48

S33073

15.28

S59793

13.33

S81831

23.57

S77436

11.25

S6455

42.35

S30230

14.97

S22577

45.48

S75454

70.76

S24773

50.03

S76016

46.21

S66145

29.14

S66138

48.29

S52163

17.23

S66156

14.25

N2528

73.38

N11823

61.59

N12522

18.32

N11454

81.53

N11732 N7554 60.73 30.01

N11458

83.79

N11659

56.43

N11577

29.80 N11168

35.08

N9

19.89

N180

15.51

N3861

-1.05

Q1812

27.55

N6702

-2.15

S63618

21.00

S53498

48.60

S46713

15.30

S69364

21.28

S57980

42.01

S52490

54.68

S33500

47.34

S 4460

39.02

S70488

61.49

S53360

52.63

S38491

42.17

S43641

45.88

S71785

39.02

S47453

48.09 S67197

37.31

S67074

41.25

S60812

27.75

S50546

29.53

S51298

39.18

S42762

20.38

S37681

30.89

N3475

78.06

N6580

80.46

N3934

54.67

N7650

49.65

N11396

56.53

N7493

38.42

N8214

28.94

N11166

20.69

Q2300

35.52

Q2443

29.19

Q2955

15.07

Q1187

11.16

S15514

39.18

Q2422

8.21

S33380

54.60

S21311

10.33

Date

Oct 2009

Nov 2009

Dec 2009

Jan 2010

Feb 2010Mar 2010

Apr 2010

May 2010

June 2010

July 2010

Aug 2010Sep 2010

Daily Altitude above NGVD 1929, feet 76.0

78.0

80.0

82.0

84.0

86.0 USGS 404818073293101 N 11454. 1

Daily mean altitude above NGVD 1929

Water level shown on map (NGVD 1929)

EXPLANATION

Oct 2010

NO DATA

Date

Oct 2009

Nov 2009

Dec 2009

Jan 2010

Feb 2010Mar 2010

Apr 2010

May 2010

June 2010

July 2010

Aug 2010Sep 2010

Daily Altitude above NGVD 1929, feet

2.0

4.0

6.0

8.0

10.0

12.0 USGS 404025073463801 Q 2422. 1

Daily mean altitude above NGVD 1929

Water level shown on map (NGVD 1929)

EXPLANATION

Oct 2010

Date

Oct 2009

Nov 2009

Dec 2009

Jan 2010

Feb 2010Mar 2010

Apr 2010

May 2010

June 2010

July 2010

Aug 2010Sep 2010

Daily Altitude above NGVD 1929, feet -8.0

-6.0

-4.0

-2.0

0.0

2.0 USGS 403517073430702 N 6702. 1

Daily mean altitude above NGVD 1929

Water level shown on map (NGVD 1929)

EXPLANATION

Oct 2010

Date

Oct 2009

Nov 2009

Dec 2009

Jan 2010

Feb 2010Mar 2010

Apr 2010

May 2010

June 2010

July 2010

Aug 2010Sep 2010

Daily Altitude above NGVD 1929, feet 48.0

50.0

52.0

54.0

56.0

58.0 USGS 404932073055902 S 33380. 1

Daily mean altitude above NGVD 1929

Water level shown on map (NGVD 1929)

EXPLANATION

Oct 2010

Date

Oct 2009

Nov 2009

Dec 2009

Jan 2010

Feb 2010Mar 2010

Apr 2010

May 2010

June 2010

July 2010

Aug 2010Sep 2010

Daily Altitude above NGVD 1929, feet

8.0

10.0

12.0

14.0

16.0

18.0 USGS 404030073293703 N 180. 2

Daily mean altitude above NGVD 1929

Water level shown on map (NGVD 1929)

EXPLANATION

Oct 2010

NO DATA

NO DATA

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Magothy and Jameco Aquifers

 The Magothy aquifer of upper Cretaceous age is the most extensive unit in Long 

Island’s groundwater system. This aquifer underlies most of Long Island and the offshore 

waters, except in parts of western and northern Kings and Queens Counties, northern 

Nassau County, and northwestern and northeastern Suffolk County, where it has been 

removed by erosion and glacial scour. The altitude of its upper surface ranges from more 

than 200 feet (ft) above NGVD 29 in parts of north-central Nassau County and west-central 

Suffolk County to more than 600 ft below NGVD 29 in north-central Suffolk County 

(Smolensky and others, 1989). Aquifer thickness ranges from zero in northern and western 

Kings and Queens Counties, northern Nassau County, and parts of northern Suffolk County 

to more than 1,000 ft in south-central Suffolk County (Soren and Simmons, 1987). The 

Magothy aquifer has become the principal source of water supply in Nassau and Suffolk 

Counties during the past 50 years (1963–2013) as a result of contamination in the upper 

glacial aquifer. 

 This map depicts water levels during April–May 2010 in wells screened in the 

Magothy aquifer and the hydraulically connected Jameco aquifer (in parts of western 

Long Island). Most water-level measurements used to prepare this map were made in 

wells screened near the middle of the aquifer and were supplemented by some measurements from the basal zone. Only a few measurements made in the upper part were used. 

Because vertical hydraulic gradients in the Magothy aquifer can be large, measured 

potentiometric heads at a given location can vary depending on the depth of the well 

screen. 

 The general configuration of the potentiometric surface in the Magothy aquifer is 

similar to that of the water table, rising gradually from the western part of Long Island to 

form an east-west-trending mound in Nassau and western Suffolk Counties. The surface 

of the mound then gradually declines toward the eastern end of Long Island. In areas 

where deep channels have been eroded into the Magothy aquifer and filled with glacial 

deposits, the potentiometric-surface contours were drawn from water levels measured in 

wells screened in these upper glacial aquifer deposits, which are laterally contiguous and 

hydraulically connected to the Magothy aquifer. The inferred northern limit of the Magothy aquifer, the inferred extent of the Jameco aquifer, and the aquifer in which each well 

is screened are indicated on this map. Public-supply pumping has lowered the potentiometric surface below NGVD 29 in southern Nassau County (Lusczynski and Swarzenski, 

1966).

 The altitude of the potentiometric surface in the Magothy aquifer on Long Island 

during April–May 2010 ranged from about 2 feet (ft) below NGVD 29 in extreme southwestern Nassau County to more than 83 ft above NGVD 29 in northeastern Nassau County. In 

Kings County, 2 measurements ranged from 1.33 to 5.56 ft; in Queens County, 9 measurements ranged from 4.68 to 35.52 ft; in Nassau County, 30 measurements ranged from -2.15 

to 83.79 ft; and in Suffolk County, 53 measurements ranged from 4.85 to 78.70 ft above 

NGVD 29.

SCIENTIFIC INVESTIGATIONS MAP 3270

Potentiometric surface in the Magothy and Jameco aquifers—SHEET 2 of 4

Monti, Jack, Jr., Como, Michael, and Busciolano, Ronald, 2013,

Water-Table and Potentiometric-Surface Altitudes in the Upper Glacial, Magothy, and Lloyd Aquifers beneath Long Island, New York, April–May 2010

Inferred extent of the Jameco aquifer

 

Inferred extent of the Magothy aquifer 

 

Line of equal potentiometric-surface altitude—

 Shows altitude at which the water level would have stood in 

 tightly cased wells, April-May 2010.

 Solid where approximately known; dashed where

 inferred. Contour interval 10 feet. Datum is NGVD 29

20

S 58922

2.55

Monitoring well—Red circle indicates the observation well is screened 

 in the Magothy aquifer; Red circle with thick border indicates 

 the supply well screened in the Magothy aquifer; Orange circle 

 indicates the observation well is screened in the Jameco aquifer. Upper number 

 is well number assigned by the New York State Department of 

 Environmental Conservation; lower number is potentiometric-surface 

 altitude, in feet above or below NGVD 29

EXPLANATION

388 feet

0 feet

Land surface topography—Shows land surface altitude in feet above NAVD 88