Prepared in cooperation with the New York State Department of Environmental Conservation

Aquifer Transmissivity in Nassau, Queens, and Kings 

Counties, New York, Estimated From Specific-Capacity Tests 

at Production Wells

Open-File Report 2020–1108

U.S. Department of the Interior

U.S. Geological Survey
Cover. Artistic image derived from figure 1 of this report.
Aquifer Transmissivity in Nassau, 

Queens, and Kings Counties, New York, 

Estimated From Specific-Capacity Tests at 

Production Wells

By John H. Williams, Madison Woodley, and Jason S. Finkelstein

Prepared in cooperation with the 

New York State Department of Environmental Conservation

Open-File Report 2020–1108

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DAVID BERNHARDT, Secretary

U.S. Geological Survey

James F. Reilly II, Director

U.S. Geological Survey, Reston, Virginia: 2020

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Suggested citation:

Williams, J.H., Woodley, M., and Finkelstein, J.S., 2020, Aquifer transmissivity in Nassau, Queens, and Kings 

Counties, New York, estimated from specific-capacity tests at production wells: U.S. Geological Survey Open-File 

Report 2020–1108, 7 p., https://doi.org/10.3133/ofr20201108.

Associated data for this publication:

U.S. Geological Survey, 2020, USGS water data for the Nation: U.S. Geological Survey National Water Information 

System database, https://doi.org/10.5066/F7P55KJN.

ISSN 2331-1258 (online)
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Hydrogeologic Setting...................................................................................................................................3

Upper Glacial Aquifer ...........................................................................................................................3

Jameco Aquifer .....................................................................................................................................3

Magothy Aquifer...................................................................................................................................3

Lloyd Aquifer..........................................................................................................................................4

Previous Estimates of Hydraulic Properties ..............................................................................................4

Description of Specific-Capacity Tests and Wells ...................................................................................4

Estimation Method and Limitations ............................................................................................................4

Estimated Transmissivities of Selected Production Wells ......................................................................5

Summary..........................................................................................................................................................6

References Cited............................................................................................................................................6

Figures

1. Map showing generalized surficial geology and location of selected production 

wells with specific-capacity data in Nassau, Queens, and Kings Counties, 

New York ........................................................................................................................................2

2. Generalized hydrogeologic section of principal aquifers on Long Island, 

New York; modified from Smolensky and others (1989) .........................................................3

3. Statistical box plot of transmissivity estimated from specific-capacity tests 

of selected production wells by principal aquifer, Nassau, Queens, and Kings 

Counties, Long Island, New York ................................................................................................5

Tables

1. Summary statistics of transmissivity estimated from specific-capacity tests of 

selected production wells by principal aquifer in Nassau, Queens, and Kings 

Counties, Long Island, New York ................................................................................................6

Conversion Factors

Multiply By To obtain

inch (in.) 25.4 millimeter (mm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

gallon per minute (gal/min) 0.06309 liter per second (L/s)

foot squared per day (ft2/d) 0.09290 meter squared per day (m2/d)
iv

Datum

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

Abbreviations

NWIS National Water Information System

NYSDEC New York State Department of Environmental Conservation

USGS U.S. Geological Survey
Aquifer Transmissivity in Nassau, Queens, and Kings 

Counties, New York, Estimated From Specific-Capacity 

Tests at Production Wells

By John H. Williams, Madison Woodley, and Jason S. Finkelstein

Abstract

As part of a cooperative effort between the 

U.S. Geological Survey and the New York State Department 

of Environmental Conservation to evaluate the sustainability 

of Long Island’s sole-source aquifer system, the transmissivities of four aquifers were estimated from specific-capacity 

tests at 447 production wells in Nassau, Queens, and Kings 

Counties on Long Island, New York. The specific-capacity test 

data, which included pumping rate, pumping duration, and 

drawdown, were obtained from published and unpublished 

records of driller-reported acceptance tests collected at production wells screened in the upper glacial, Jameco, Magothy, 

or Lloyd aquifers. Pumping rates from the production wells 

during the tests generally were greater than 400 gallons per 

minute and ranged up to 1,800 gallons per minute. Pumping 

duration generally was 8 hours or more. Transmissivities 

were estimated from the specific-capacity data by the CooperJacob approximation of the Theis equation. The transmissivity 

estimates are considered rough approximations because the 

aquifers do not meet the ideal assumptions of the method, 

well losses and partial penetration were not accounted for, 

and aquifer storage coefficients were not known but were only 

estimated from available data.

The transmissivities estimated from production wells 

screened in the upper glacial aquifer in the outwash plain 

south of the moraine generally were greater than those of the 

aquifer north of the moraine. The transmissivities estimated 

from the wells screened in the upper glacial aquifer south 

of the moraine typically ranged (as defined by the 10th and 

90th percentiles) from 3,800 to 15,000 feet squared per day 

(ft2/d), with a median value of 7,300 ft2/d. The transmissivities estimated from the wells screened in the upper glacial 

aquifer north of the moraine typically ranged from 2,100 to 

7,400 ft2/d, with a median value of 4,400 ft2/d. The Jameco 

aquifer generally had the highest estimated transmissivities of 

all the aquifers analyzed. The estimated transmissivities for the 

Jameco aquifer typically ranged from 5,500 to 43,000 ft2/d, 

with a median value of 16,000 ft2/d. The Magothy and Lloyd 

aquifers had similar estimated transmissivities. The transmissivities estimated for the Magothy aquifer typically ranged 

from 2,700 to 13,000 ft2/d, with a median of 7,100 ft2/d. The 

estimated transmissivities of the Lloyd typically ranged from 

3,000 to 14,000 ft2/d, with a median of 7,200 ft2/d.

Introduction

In 2016, the U.S. Geological Survey (USGS) began a 

cooperative study with the New York State Department of 

Environmental Conservation (NYSDEC) to evaluate the sustainability of Long Island’s sole-source aquifer system through 

hydrogeologic mapping, monitoring of groundwater quality 

and levels, and construction of a groundwater-flow model. As 

part of the groundwater sustainability study, specific-capacity 

test data from published and unpublished records were 

analyzed to estimate transmissivity of selected production 

wells in Nassau, Queens, and Kings Counties on Long Island, 

New York (fig. 1).
2 Aquifer Transmissivity in Long Island, New York, Estimated From Specific-Capacity Tests at Production Wells

A

A'

KINGS COUNTY

QUEENS COUNTY

 NASSAU COUNTY

SUFFOLK COUNTY

NEW

JERSEY

Long Island

Sound

ATLANTIC 

OCEAN

NEW YORK

PA

NJ

CT

RI

MA

VT NH

Study area

ATLANTIC OCEAN

73°20'W 73°40'W 74°W

40°50'N40°40'N40°30'N

EXPLANATION

Surficial geology

Outwash

Kame moraine

Till and outwash

Till moraine

Upper glacialMagothy

Jameco

Lloyd

Well—Aquifer where

well is screened

Base from U.S. Geological Survey digital data, 2019

0 5

0 5

10 MILES

10 KILOMETERS

Figure 1. Generalized surficial geology and location of selected production wells with specific-capacity data in Nassau, Queens, and Kings Counties, New York. Surficial geology modified from Cadwell (1989).
Hydrogeologic Setting 3

Hydrogeologic Setting

The hydrogeologic setting of Long Island is presented 

in Smolensky and others (1989). The principal aquifers are 

the upper glacial, Jameco, Magothy, and Lloyd. The hydrogeologic characteristics of the four aquifers are summarized below.

Upper Glacial Aquifer

Till, kame, outwash, lacustrine, and marine sediments 

deposited during the Pleistocene epoch form the upper glacial 

aquifer of Long Island. Till is a poorly permeable unsorted 

mixture of clay, silt, sand, and stones deposited beneath and 

adjacent to glacial ice. Kame sediments are variably sorted 

ice-contact deposits of sand, gravel, and silt that range in 

permeability. Outwash sediments consist of well-sorted sand 

and gravel deposited in front of glacial ice that are moderately 

to highly permeable. Moraines, formed by a heterogeneous 

mix of till and kame sediments, mark the southernmost extent 

of glacial ice on Long Island (fig. 1). The most extensive 

deposits of outwash underlie the southern part of Long Island 

in front of the moraines. Outwash deposits are present with 

the till north of the moraines but are less extensive. Lacustrine 

deposits, present mostly in central and eastern Long Island, 

and marine deposits, locally present along the south shore, are 

dominantly fine-grained deposits with poor permeability but 

contain thin local lenses of sand and gravel that are moderately 

permeable. The upper glacial aquifer is in hydraulic contact 

with the Magothy aquifer except along the southern shore 

where the Gardiners clay restricts vertical flow between the 

aquifers (fig. 2).

Jameco Aquifer

The Jameco aquifer, formed during the Pleistocene 

epoch, lies unconformably beneath and is confined by the 

Gardiners clay on the southern shore of Nassau, Queens, and 

Kings Counties (fig. 2). The Jameco aquifer is a fluvial deposit 

of fine to coarse sand and gravel deposited in channels eroded 

into the underlying Magothy deposits. The Jameco deposits are up to 200 feet (ft) thick and are moderately to highly 

permeable.

Magothy Aquifer

The Magothy aquifer, formed during the Cretaceous 

period, extends throughout most of Long Island. In Nassau, 

Queens, and Kings Counties, it lies unconformably beneath 

the upper glacial aquifer in the northern and central areas 

and the Jameco aquifer and Gardiners clay on the southern 

shore (fig. 2). The Magothy deposits are up to 600 ft thick and 

consist of alternating beds of sand, silt, and clay with gravel 

common in the basal zone.

Bedrock

Lloyd aquifer

Raritan clay

Magothy aquifer

Jameco aquifer

Gardiners clay

Upper glacial aquifer

Unsaturated zone

Long Island Sound ATLANTIC OCEAN

NOT TO SCALE

A A'

Figure 2. Generalized hydrogeologic section of principal aquifers on Long Island, New York; modified from Smolensky and others 

(1989). Location of cross section shown on figure 1.
4 Aquifer Transmissivity in Long Island, New York, Estimated From Specific-Capacity Tests at Production Wells

Lloyd Aquifer

The Lloyd aquifer of Cretaceous age lies conformably 

beneath and is confined by the Raritan clay (fig. 2). The Lloyd 

aquifer rests unconformably on bedrock throughout most of 

Long Island and is up to 400 ft thick. The Lloyd aquifer consists of fine to coarse sand and gravel with lenses of silty clay.

Previous Estimates of Hydraulic 

Properties

Transmissivity and hydraulic conductivity estimates 

for aquifers on Long Island from selected areal groundwater appraisals and aquifer-test site studies were previously 

summarized by McClymonds and Franke (1972). These 

estimates of aquifer hydraulic properties were derived from 

specific-capacity tests (pumping rate and drawdown data) and 

aquifer tests (single- and multiple-well time-drawdown data) 

through analytical methods. McClymonds and Franke (1972)

also published statistical summaries and contoured maps 

of transmissivity and hydraulic conductivity of the aquifers 

based on an analysis of specific capacities, screen lengths, 

and lithologic logs from production-well completion reports. 

Lindner and Reilly (1982), Aronson and others (1983), Prince 

and Schneider (1989), and Cartwright (1997) used numerical 

radial-flow models, and Misut and Busciolano (2009) used 

analytical models to estimate hydraulic properties at selected 

aquifer-test sites on Long Island. Estimates of aquifer hydraulic properties from these previous studies associated with 

specific well sites are available from the USGS National Water 

Information System database (NWIS; U.S. Geological Survey, 

2020a) and can be viewed through the Aquifer Test Locator 

graphical user interface (U.S. Geological Survey, 2020b).

Description of Specific-Capacity Tests 

and Wells

Specific-capacity test and well-construction data were 

compiled for 447 tested well sites from a previously published 

compilation by Chu (1996) for Kings and Queens Counties 

and from unpublished paper records for Nassau and western 

Suffolk Counties. Approximately half of the tested well sites 

were screened in the Magothy aquifer, and one-quarter were 

screened in the upper glacial aquifer in the outwash plain 

south of the moraine deposits. The specific-capacity test and 

well-construction data, which included test date, pumping 

rate and duration, water levels before and during pumping, 

screen length and diameter, and depth of top and bottom of the 

screened interval, were sourced from completion reports of 

production well-acceptance tests conducted from 1919 to 1982 

(NYSDEC, written commun., 1982). The specific-capacity test 

and well-construction data compiled for this study were added 

to the well location, altitude, and aquifer data previously 

entered in NWIS; the NWIS data can be mapped through the 

Aquifer Test Locator graphical user interface (U.S. Geological 

Survey, 2020b).

The production wells typically were screened in the more 

transmissive part of the aquifer that was penetrated during 

drilling. Well-screen depths were as shallow as 20 ft below 

land surface in the upper glacial aquifer to as deep as 1,280 ft 

below land surface in the Lloyd aquifer on the barrier-beach 

islands. Median well-screen lengths were 20 ft in the upper 

glacial aquifer north of the moraine, 29 ft in the upper glacial aquifer south of the moraine, 20 ft in the Jameco aquifer, 

52 ft in the Magothy aquifer, and 60 ft in the Lloyd aquifer. 

Pumping rates from the production wells during the tests generally were greater than 400 gallons per minute (gal/min) and 

ranged up to 1,800 gal/min. Pumping durations generally were 

8 hours or more.

Estimation Method and Limitations

The transmissivities of the aquifers at the selected production wells were estimated from the specific-capacity test 

and well-construction data following the method of Bradbury 

and Rothschild (1985). The method applies the Cooper-Jacob 

approximation of the Theis (1935) equation:

T Q

s s

Tt

r S

s

m w w

 p

  





 



 













 4 

2 25 2 2 

ln . , (1)

where

T is transmissivity, in feet squared per day;

Q is pumping rate, in cubic feet per day;

sm is measured drawdown, in feet;

sw is well loss, in feet;

t is time since pumping began, in days;

rw is effective wellbore radius, in feet;

S is aquifer storage coefficient 

(dimensionless); and

sp is the partial-penetration correction factor 

(dimensionless).

The iterative solution of equation 1 is based on an initial guess 

of T, and Q, sm, and t from the specific-capacity test. The 

method assumes that the tested aquifer is confined, nonleaky, 

homogeneous, and isotropic; flow is radial to the pumping 

well; well loss is known; aquifer thickness is known; and 

the storage coefficient of the aquifer is known. The transmissivities estimated in this study are considered to be rough 

approximations because the aquifers do not meet these ideal 

assumptions, well losses were not considered (sw=0), the 

partial-penetration correction was not applied (sp=0), and 

storage coefficients (S) were approximated. Step-drawdown 

tests that are used to determine well-loss coefficients were 

not available for the production wells. Because of high 
Estimated Transmissivities of Selected Production Wells 5

pumping rates, well losses may be substantial in some wells 

tested, causing reduced specific capacities and estimates of 

transmissivity.

The degree of partial penetration is dependent on the 

length of the well screen in relation to the thickness of the 

aquifer tested. Although well-screen lengths were available, 

drawdown data in surrounding observation wells and detailed 

lithologic logs that are needed to determine the effective 

aquifer thickness were lacking at the production-well test 

sites. Not applying the partial-penetration correction used in 

the Bradbury and Rothschild (1985) method to the partially 

penetrating production wells in this study should have resulted 

in lower transmissivity estimates than if the partial-penetration 

correction had been applied. Also, the partial-penetration correction factor used in the method assumes that the horizontal 

hydraulic conductivity is equal to the vertical hydraulic conductivity, which is not the case for the aquifers of Long Island. 

Because of the sedimentary depositional environments of the 

aquifers on Long Island, horizontal hydraulic conductivity is 

at least an order of magnitude greater than vertical hydraulic conductivity in the aquifers, with the Magothy aquifer 

displaying the greatest vertical anisotropy (Smolensky and 

others, 1989). Applying the partial-penetration correction to a 

vertically anisotropic aquifer should result in overestimation 

of transmissivity values.

Storage coefficients for the aquifers at the productionwell test sites were not known but were approximated based 

on published values from Lindner and Reilly (1982), Prince 

and Schneider (1989), Cartwright (1997), and Misut and 

Busciolano (2009). Storage values used in the present analysis were as follows: 0.15 for wells screened within 200 ft of 

the water table in the unconfined upper glacial and Magothy 

aquifers; 0.003 for wells screened 200 ft below the water table 

in the semiconfined upper glacial and Magothy aquifers; and 

2×10−5 for the confined Jameco, Magothy, and Lloyd aquifers. 

Storage is one of the less sensitive parameters; for example, 

using an unconfined storage value for a semiconfined aquifer 

would decrease the transmissivity estimate by less than 20 percent, whereas, conversely, using a confined storage value 

would increase the transmissivity estimate by not more than 

the same percentage.

Estimated Transmissivities of Selected 

Production Wells

The estimated transmissivities of the selected production wells and the specific-capacity and well-construction 

data are available from the NWIS database and are viewable 

through the Aquifer Test Locator graphical user interface 

(U.S. Geological Survey, 2020b). The estimated transmissivities at the production wells of the upper glacial aquifer in the 

outwash plain south of the moraine were generally greater 

than those north of the moraine (fig. 3; table 1). The estimated transmissivities at the wells in the upper glacial aquifer 

25

113

49

224 36

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

Transmissivity, in feet squared per day

Principal aquifer

EXPLANATION

Upper glacial—North of moraine

Jameco

Lloyd

Principal aquifer

Upper glacial—South of moraine

Magothy

90th percentile

Number of tests

10th percentile

75th percentile

25th percentile

50th percentile (median)

113

Figure 3. Statistical box plot of transmissivity estimated from specific-capacity tests of selected production wells by principal aquifer, 

Nassau, Queens, and Kings Counties, Long Island, New York.
6 Aquifer Transmissivity in Long Island, New York, Estimated From Specific-Capacity Tests at Production Wells

Table 1. Summary statistics of transmissivity estimated from specific-capacity tests of selected production wells by principal aquifer 

in Nassau, Queens, and Kings Counties, Long Island, New York.

Aquifer Number of 

wells

Median screen length, 

in feet

Transmissivity, by percentile, in feet squared per day

10th 25th Median 75th 90th

Upper glacial, north of moraine 25 20 2,100 3,600 4,400 5,700 7,400

Upper glacial, south of moraine 113 29 3,800 5,300 7,300 11,000 15,000

Jameco 49 20 5,500 9,700 16,000 25,000 43,000

Magothy 224 52 2,700 4,800 7,100 9,900 13,000

Lloyd 36 60 3,000 4,900 7,200 11,000 14,000

on the outwash plain south of the moraine typically ranged 

(as defined by the 10th and 90th percentiles) from 3,800 to 

15,000 feet squared per day (ft2/d) and had a median value of 

7,300 ft2/d. The estimated transmissivities at the wells in the 

upper glacial aquifer north of the moraine deposits typically 

ranged from 2,100 to 7,400 ft2/d and had a median value of 

4,400 ft2/d. Production wells in the Jameco aquifer generally 

had the greatest estimated transmissivities of all the aquifers. 

The estimated transmissivities at the production wells in the 

Jameco aquifer typically ranged from 5,500 to 43,000 ft2/d and 

had a median value of 16,000 ft2/d. The estimated transmissivities of the production wells in the Magothy and Lloyd 

aquifers generally were similar. The estimated transmissivities at the wells in the Magothy aquifer typically ranged from 

2,700 to 13,000 ft2/d and had a median of 7,100 ft2/d. The 

estimated transmissivities at the wells in the Lloyd aquifer 

typically ranged from 3,000 to 14,000 ft2/d and had a median 

of 7,200 ft2/d.

Summary

As part of a cooperative effort between the 

U.S. Geological Survey and the New York State Department 

of Environmental Conservation to evaluate the sustainability 

of Long Island’s sole-source aquifer system, the transmissivities of 447 production wells in Nassau, Queens, and Kings 

Counties on Long Island, New York, were estimated from 

specific-capacity tests. The specific-capacity test data, which 

included pumping rate, pumping duration, and drawdown, 

were obtained from published and unpublished records of 

driller-reported acceptance tests collected at production wells 

screened in the upper glacial, Jameco, Magothy, or Lloyd 

aquifers. Median well-screen lengths ranged from less than 

30 ft in the upper glacial and Jameco aquifers to more than 

50 ft in the Magothy and Lloyd aquifers. Pumping rates from 

the production wells during the tests generally were greater 

than 400 gallons per minute and ranged up to 1,800 gallons 

per minute. Pumping duration generally was 8 hours or more.

Transmissivity was estimated from the specific-capacity 

data by the Cooper-Jacob approximation of the Theis 

equation. The transmissivity values are considered rough 

approximations because the aquifers do not meet the ideal 

assumptions of the method, well losses and partial penetration were not accounted for, and storage was not known but 

estimated from available data.

The estimated transmissivities at the production wells in 

the upper glacial aquifer south of the moraine generally were 

greater than those of the aquifer north of the moraine. Wells in 

the Jameco aquifer generally had greater estimated transmissivities than those in the other aquifers. Wells in the Magothy 

and Lloyd aquifers had similar estimated transmissivities. 

The median aquifer transmissivities were 4,400 ft2/d for the 

upper glacial aquifer north of the moraine, 7,300 ft2/d for the 

upper glacial aquifer south of the moraine, 16,000 ft2/d for 

the Jameco aquifer, 7,100 ft2/d for the Magothy aquifer, and 

7,200 ft2/d for the Lloyd aquifer.

References Cited

Aronson, D.A., Lindner, J.B., and Katz, B.G., 1983, 

Geohydrology of the Meadowbrook artificial-recharge 

site at East Meadow, Nassau County, New York: 

U.S. Geological Survey Water-Resources Investigations 

Report 82–4084, 44 p. [Also available at https://doi.org/

10.3133/wri824084.].

Bradbury, K.R., and Rothschild, E.R., 1985, A computerized technique for estimating the hydraulic conductivity of 

aquifers from specific capacity data: Ground Water, v. 23, 

no. 2, p. 240–246. [Also available at https://doi.org/10.1111/

j.1745-6584.1985.tb02798.x.].

Cadwell, D.H., 1989, Surficial geologic map of New York—

Lower Hudson Sheet: New York State Museum Map and 

Chart Series 40, 1 sheet, scale 1:250,000. [Also available 

at http://www.nysm.nysed.gov/common/nysm/files/surf_

lowerhudson.jpg.]

Cartwright, R.A., 1997, Hydrogeologic-setting classification for Suffolk County, Long Island, New York; with 

results of selected aquifer-test analyses: U.S. Geological 

Survey Open-File Report 96–457, 18 p. [Also available at 

https://doi.org/10.3133/ofr96457.].
References Cited 7

Chu, A., 1996, Results of specific-capacity tests in Kings and 

Queens Counties, New York, 1919–82: U.S. Geological 

Survey Open-File Report 96–575, 12 p. [Also available at 

https://doi.org/10.3133/ofr96575.].

Lindner, J.B., and Reilly, T.E., 1982, Analysis of three tests 

of the unconfined aquifer in southern Nassau County, Long 

Island, New York: U.S. Geological Survey Water-Resources 

Investigations Report 82–4021, 46 p. [Also available at 

https://doi.org/10.3133/wri824021.].

McClymonds, N.E., and Franke, O.L., 1972, Water transmitting properties of aquifers on Long Island, New York: 

U.S. Geological Survey Professional Paper 627–E, 24 p. 

[Also available at https://doi.org/10.3133/pp627E.].

Misut, P.E., and Busciolano, R., 2009, Hydraulic properties of the Magothy and upper glacial aquifers at 

Centereach, Suffolk County, New York: U.S. Geological 

Survey Scientific Investigations Report 2009–5190, 23 p. 

[Also available at https://doi.org/10.3133/sir20095190.].

Prince, K.R., and Schneider, B.J., 1989, Estimation of hydraulic characteristics of the upper glacial and Magothy aquifers at East Meadow, New York, by use of aquifer tests: 

U.S. Geological Survey Water-Resources Investigations 

Report 87–4211, 43 p. [Also available at https://doi.org/

10.3133/wri874211.].

Smolensky, D.A., Buxton, H.T., and Shernoff, P.K., 1989, 

Hydrologic framework of Long Island, New York: 

U.S. Geological Survey Hydrologic Investigations 

Atlas 709, 3 sheets, scale 1:250,000. [Also available at 

https://doi.org/10.3133/ha709.]

Theis, C.V., 1935, The relation between the lowering of the 

piezometric surface and the rate and duration of discharge 

of wells using groundwater storage—Eos, American 

Geophysical Union: Transactions, v. 16, p. 519–524.

U.S. Geological Survey, 2020a, USGS water data for the 

Nation: U.S. Geological Survey National Water Information 

System database, accessed May 8, 2020, at https://doi.org/

10.5066/F7P55KJN.

U.S. Geological Survey, 2020b, Aquifer test locator: 

U.S. Geological Survey web page, accessed May 8, 2020, at 

https://ny.water.usgs.gov/maps/aq-test/.

For more information about this report, contact:

Director, New York Water Science Center

U.S. Geological Survey

425 Jordan Road

Troy, NY 12180–8349

dc_ny@usgs.gov

(518) 285–5602

or visit our website at

https://www.usgs.gov/centers/ny-water

Publishing support provided by the

Pembroke Publishing Service Center
Williams and others—Aquifer Transmissivity in Long Island, New York, Estimated From Specific-Capacity Tests at Production Wells—OFR 2020–1108

ISSN 2331-1258 (online)

https://doi.org/10.3133/ofr20201108