Occurrence of Pharmaceuticals in Shallow 

Ground Water of Suffolk County, New York, 

2002–2005

By Mark J. Benotti, Shawn C. Fisher, and Stephen A. Terracciano

Prepared in cooperation with the Suffolk County Water Authority

Open-File Report 2006–1297

U.S. Department of the Interior

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

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2006

For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment:

World Wide Web: http://www.usgs.gov

Telephone: 1-888-ASK-USGS

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Benotti, M.J., Fisher, S.C., and Terracciano, S.A., 2006, Occurrence of pharmaceuticals in shallow ground water of 

Suffolk County, New York, 2002–2005: U.S. Geological Survey Open-File Report 2006–1297, 5 pages, online only.
iii

Contents

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

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

Methods...........................................................................................................................................................1

Occurrence of Pharmaceuticals.................................................................................................................2

Conclusions.....................................................................................................................................................5

Acknowledgments.........................................................................................................................................5

References Cited............................................................................................................................................5

Figures

1. Map showing locations of the 61 wells sampled during 2002–2005 in Suffolk County, 

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

2. Graph showing concentrations of pharmaceuticals detected in 61 wells in Suffolk 

County, Long Island, N.Y. .............................................................................................................3

Tables

1. Comparison of median detected concentrations and detection frequencies between 

pharmaceuticals in 61 ground-water wells in Suffolk County, Long Island, New York, 

2002-2005, and 139 streams throughout the United States during 1998–2000...........................4

List of Acronyms

MDL Method detection limits

PhAC Pharmaceutically active compound

PPCP Pharmaceutical and personal-care products

SCWA Suffolk County Water Authority

USGS U.S. Geological Survey

Abbreviations, Acronyms, And Datums

Abbreviated Units of Measurement

μg/L micrograms per liter

μm micrometer

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).
iv

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Occurrence of Pharmaceuticals in Shallow Ground Water 

of Suffolk County, New York, 2002–2005

By Mark J. Benotti, Shawn C. Fisher, and Stephen A. Terracciano

is discharged to the surficial aquifer, yet an extensive survey of 

PhAC contamination of ground water has not been conducted. 

Ground water is the sole source of drinking water for Suffolk 

County’s population of 1.4 million. The shallow sand and 

gravel aquifer, commonly called the upper glacial aquifer, may 

be susceptible to wastewater contamination from discharges 

of wastewater-treatment facilities and domestic cesspools 

and septic tanks. About 75 percent of the wastewater entering 

the upper glacial aquifer comes from domestic cesspools and 

septic tanks; the remainder comes from municipal and private 

wastewater-treatment plants.

In 2002, the U.S. Geological Survey (USGS), in 

cooperation with the Suffolk County Water Authority 

(SCWA), began a 4-year study to document the occurrence of 

PhACs in ground-water wells throughout Suffolk County. This 

report summarizes the results from this study and relates the 

concentrations and frequencies of detection to those reported 

from a 1998–2000 nationwide study of streams that receive 

wastewater (Kolpin and others, 2002).

Methods

Seventy samples were collected from 61 wells close to 

wastewater-treatment facilities that discharge effluent to the 

upper glacial aquifer (fig. 1) to assess the occurrence of PhACs 

in shallow ground-water near the discharge points. All wells 

were within a mile of a wastewater treatment facility and were 

in partly unsewered areas that also contained domestic septic 

tanks and cesspools. All wells were sampled in accordance 

with established sampling methods (US Geological Survey, 

variously dated). Samples were collected in 1-liter bottles, 

filtered at the USGS office in Coram, N.Y. through Gellman 

0.7 μm baked glass-fiber filters, then shipped overnight to 

the USGS National Water Quality Laboratory in Denver, 

Colo., for extraction and analysis of 24 compounds (table 1). 

The samples were solid-phase extracted and analyzed on a 

liquid chromatography-mass spectrometry system operated 

in selected-ion-monitoring mode. Details of the extraction 

and analysis method are given in Cahill and others (2004). 

Method detection limits (MDLs) were established as part of 

a long-term laboratory study and are available on the USGS 

Abstract

Seventy (70) water samples were collected from 61 

wells in the upper glacial and Magothy aquifers (9 wells 

were sampled twice) during 2002–05 and analyzed for 24 

pharmaceuticals. Wells were selected for their proximity 

to known wastewater-treatment facilities that discharge to 

the shallow upper glacial aquifer. Of the 70 samples taken, 

pharmaceuticals were detected in 28, of which 19 contained 

one compound, and 9 contained two or more compounds. 

Concentrations of detected compounds were extremely low; 

most ranged from 0.001 to 0.1 microgram per liter (part per 

billion). The two most commonly detected compounds were 

carbamazepine (an antiepileptic drug) and sulfamethoxazole 

(an antibiotic). Occurrence of pharmaceutical compounds 

in Suffolk County ground water is less prevalent than in 

susceptible streams of the United States that were tested in 

1998–2000, but the similarity of median concentrations of the 

detected compounds of the two data sets indicates that current 

wastewater practices can serve to introduce pharmaceuticals to 

this shallow aquifer.

Introduction

Aquatic environments that receive treated wastewater 

have been found to contain pharmaceutically active 

compounds (PhACs; Daughton and Ternes, 1999). This 

class of organic compounds includes prescription and nonprescription drugs, compounds (such as caffeine) that are 

added to consumables that elicit a biological effect, and (or) 

human metabolites of such compounds (for example cotinine, 

the primary human metabolite of nicotine). These compounds 

are discharged to the environment in the effluent from 

domestic or municipal wastewater-treatment systems, as well 

as from untreated sewage discharged during combined sewer 

overflow events or from leaky sewers. To date, the two most 

extensive studies of pharmaceutical occurrence in the United 

States have focused on surface waters that receive treated 

wastewater (Kolpin and others, 2002; Glassmeyer and others, 

2005). In many areas of the United States, treated wastewater 
National Water Quality Web site (http://nwql.usgs.gov). Only 

concentrations greater than the MDL and greater than 10 times 

the concentration detected in a laboratory blank are reported 

herein. A total of 156 qualitatively identified detections were 

made, but only 54 quantified concentrations were reportable 

because 81 detections were less than the MDL, and 21 were 

less than 10 times the concentration in a corresponding 

laboratory blank.

Occurrence of Pharmaceuticals

More than half (42) of the 70 samples were free of all 24 

compounds. Of the remaining 28 samples, 19 contained only 

one PhAC, and 9 contained two or more. The distribution of 

measured concentrations is plotted in figure 2, which includes 

median detected concentrations for the 139 susceptible 

streams sampled throughout the United States during 1998–

2000 (Kolpin and others, 2002). In general, concentrations in 

the ground-water samples were similar to those reported in 

streams. Whether these concentrations represent amounts to 

which people are exposed from tap water is unknown because 

two studies (Adams and others, 2002; Boyd and others, 2003) 

have shown that chlorination of public-supply water before 

distribution to homes removes pharmaceuticals through 

chemical oxidation, whereas another study (Stackleberg 

and others, 2004) showed that some organic wastewater 

contaminants, including selected pharmaceuticals, persist 

through the drinking-water treatment process.

The frequency of detection for individual compounds 

is summarized in table 1. Only 13 of the 24 compounds for 

which the samples were analyzed were detected. Eleven of 

24 compounds were not detected in any of the samples. The 

most frequently detected compounds were carbamazepine, a 

prescription antiepileptic drug (detected in 26 percent, or 18 

EXPLANATION

Suffolk County, New York

Wells sampled in this study

0 5 10 20 MILES

LONG ISLAND SOUND

A T L A N T I C O C E A N

74°00' 73°20' 72°40' 72°00'

40°40'

41°00'

41°20'

41°40' NEW YORK

NEW JERSEY

CONNECTICUT

MASSACHUSETTS

RHODE

ISLAND

0 10 20 40 KILOMETERS

Suffolk County, N.Y.

area of interest

Figure 1. Locations of the 61 wells sampled during 2002–05 in Suffolk County, New York.

   Occurrence of Pharmaceuticals in Shallow Ground-Water of Suffolk County, New York, 2002–05
of 70 samples) and sulfamethoxazole, a widely used antibiotic 

(detected in 13 percent, or 9 of 70 samples). These two 

compounds were found by other studies to be among the most 

commonly detected pharmaceutical contaminants (Kolpin and 

others, 2002; Clara and others, 2004; Bendz and others, 2005). 

None of the other 11 detected compounds were found in more 

than 10 percent of the samples.

Comparison of these results with those reported for 

susceptible streams in the United States (Kolpin and others, 

2002) reveals two distinct trends (table 1). First, the median 

concentrations of detected pharmaceuticals in surface waters 

are similar to the median observed in Suffolk County ground 

water. Second, the detection frequency for the surface-water 

samples was higher than for ground-water samples. Of the 

11 compounds detected in both studies (presented in bold), 5 

had median concentrations that were similar (within a factor 

of 2) in both data sets; these compounds were acetaminophen, 

caffeine, codeine, cotinine, and gemfibrozil. Another five 

of the compounds detected in both samples had median 

concentrations more than three times greater in surfacewater samples than in the Suffolk County ground-water 

samples; these compounds were dehydronifedipine, diltiazem, 

paraxanthine, sulfamethoxazole, and trimethoprim. Only one 

compound (fluoxetine) was found in greater concentration in 

ground water than in surface water: measured ground-water 

concentrations were roughly 10 times higher than the reported 

surface-water median concentration.

Comparison of the detection frequency of the 11 

compounds present in both studies indicates that only 1 

compound (sulfamethoxazole) was detected in more than 

10 percent of the ground-water samples; the remaining 

10 compounds detected in fewer than 10 percent of the 

samples were acetaminophen, caffeine, codeine, cotinine, 

dehydonifedipine, diltiazem, fluoxetine, gemfibrozil, 

0.00001

0.0001

0.001

0.01

0.1

1

10

Acetaminophen

Azithromycin

Caffeine

Carbamazepine

Cimetidine

Codeine

Cotinine

Dehydronifedipin

Diltiazem

DiphenhydramineErythromycin

FluoxetineFurosemide

Gemfibrozil

Ibuprofen

Metformin

MiconazoleParaxanthineRanitidine

Salbutamol

Sulfamethoxazole

TrimethoprimThiobendazole

Warfarin

ndndndndndndndndndnd

CONCENTRATIONS, IN MICROGRAMS PER LITER

Pharmaceutical concentration in ground-water well

Median detected concentrations in U.S. streams

(from Kolpin and others, 2002)

nd not detected in this study

nd

Figure 2. Concentrations of pharmaceuticals detected in 61 wells in Suffolk County, Long Island, N.Y. (Locations of wells are shown in 

figure 1).

Occurrence of Pharmaceuticals 
paraxanthine and trimethoprim. The surface-water samples, 

in contrast, showed detection of 8 of the 11 compounds 

(acetaminophen, caffeine, cotinine, dehydronipedipine, 

diltiazem, paraxanthine, sulfamethoxazole, and trimethoprim), 

in more than 10 percent of samples; only codeine, 

fluoxetine, and gemfibrozil were found in fewer than 10 

percent of samples.

The effects of treated municipal effluent, and domestic 

septic-tank and cesspool effluent on local ground-water 

supplies are unknown. The absolute PhAC concentration in 

the ground-water samples was low, that is, the mass of each 

compound in 1 liter of ground-water was 5 to 7 orders of 

magnitude (100,000 to 10,000,000 times) lower than a typical 

therapeutic dose, and any toxic effects associated with such 

concentrations are unlikely (Halling-Sorensen and others, 

1998; Kolpin and others, 2002). PhACs have been suggested 

as reliable tracers of wastewater (Buerge and others, 2003; 

Clara and others, 2004). Their presence in Suffolk County 

ground water therefore indicates the presence of wastewater in 

the aquifer and, thus, potential contamination from nutrients 

and pathogens. Additional research is needed to define the 

fluxes of PhACs to ground water and define the relative 

amounts of contamination from municipal wastewater or 

domestic septic-tank and cesspool effluent.

Table 1. Comparison of median detected concentrations and detection frequencies between pharmaceuticals in 61 ground-water 

wells in Suffolk County, Long Island, New York, 2002-2005, and 139 streams throughout the United States during 1998–2000.

[μg/L, micrograms per liter. Detection frequencies are the percentage of samples in which compound was detected; surface-water frequency values are 

percentage of 139 samples. Boldface denotes compounds detected in both data sets. nd, not detected. --, compound not reported in 2002 surface water 

publication. Surface-water data from Kolpin and others (2002)]

Compound

Suffolk County wells U.S. streams

Median detected 

concentration

(μg/L)

Detection 

frequency 

(percent)

Median detected 

concentration 

(μg/L)

Detection 

frequency 

(percent)

Acetaminophen 0.10 4.3 0.11 23.8

Azithromycin nd 0 -- --

Caffeine 0.067 4.3 0.081 61.9

Carbamazapine 0.005 26 -- --

Cimetidine nd 0 0.074 9.5

Codeine 0.020 1.4 0.012 6.5

Cotinine 0.045 4.3 0.024 38.1

Dehydronifedipine 0.0004 4.3 0.012 14.3

Diltiazem 0.0014 1.4 0.021 13.1

Diphenhydramine nd 0 -- --

Erythromycin nd 0 0.1 21.5

Fluoxetine 0.17 4.3 0.012 1.2

Furosemide nd 0 -- --

Gemfibrozil 0.055 2.9 0.048 3.6

Ibuprofen nd 0 0.20 9.5

Metformin nd 0 0.11 4.8

Miconazole nd 0 -- --

Paraxanthine 0.040 4.3 0.11 28.6

Ranitidine nd 0 0.01 1.2

Salbutamol nd 0 nd 0

Sulfamethoxazole 0.0091 13 0.066 19.0

Thiabendazole 0.0008 5.7 -- --

Trimethoprim 0.0001 1.4 0.013 27.4

Warfarin nd 0 nd 0

 Occurrence of Pharmaceuticals in Shallow Ground-Water of Suffolk County, New York, 2002–05
Conclusions

Shallow ground water close to wastewater discharge 

points in Suffolk County contains low, but measurable 

concentrations of several PhACs. Of the 61 wells selected 

for sampling, 19 contained only one of the 24 compounds 

for which samples were analyzed and 9 samples contained 

two or more. Detected concentrations in ground-water 

wells were similar to those reported in susceptible streams 

sampled in a 1998–2000 study and 5 to 7 orders of magnitude 

below therapeutic doses. Detection frequency of individual 

compounds in ground water was generally lower than in the 

susceptible surface waters. Shallow ground water in areas 

in which treated wastewater is discharged to the underlying 

aquifer have the potential for contamination with PhACs.

Acknowledgments

Thanks are extended to Edward T. Furlong, Jeffery D. 

Cahill, and Steven L. Werner of the USGS National Water 

Quality Laboratory for their help with sample analysis and 

data interpretation. Thanks are also extended to Edward T. 

Furlong and Patrick Phillips of the USGS, and Stephen Jones 

of SCWA for their helpful revisions of this report.

References Cited

Adams, C.D., Wang, Y., Loftin, K.A., and Meyer, M., 2002, 

Removal of antibiotics from surface and distilled water 

in conventional water treatment processes: Journal of 

Environmental Engineering, v. 128, p. 253–260.

Bendz, David, Paxeus, N.A., Ginn, T.R., and Loge, F.J., 2005, 

Occurrence and fate of pharmaceutically active compounds 

in the environment, a case study: Hoje River in Sweden: 

Journal of Hazardous Materials, v. 122, p. 195–204.

Boyd, G.R., Reemtsma, Helge, Grimm, D.A., and Mitra, 

Siddhartha, 2003, Pharmaceuticals and personal care 

products (PPCPs) in surface and treated waters of 

Louisiana, USA and Ontario, Canada: Science of the Total 

Environment, v. 311, p. 135–149.

Buerge, I.J., Poiger, T.F., Muller, M.D., and Buser, H.R., 

2003, Caffeine, an anthropogenic marker for wastewater 

contamination in surface waters: Environmental Science 

and Technology, v. 37, p. 691–700.

Cahill, J.D., Furlong, E.T., Burkhardt, M.R., Kolpin, D.W., 

and Anderson, L.G., 2004, Determination of pharmaceutical 

compounds in surface- and ground-water samples by 

solid-phase extraction and high-performance liquid 

chromatography-electrospray ionization mass spectrometry: 

Journal of Chromatography A, v. 1041, p. 171–180.

Clara, Manfred, Strenn, Birgit, and Kreuzinger, Norbert, 

2004, Carbamazepine as a possible anthropogenic marker 

in the aquatic environment: Investigations on the behaviour 

of Carbamazepine in wastewater during groundwater 

infiltration: Water Research, v. 38, p. 947–954.

Daughton, C.G. and Ternes, T.A., 1999, Pharmaceuticals and 

personal care products in the environment: Agents of subtle 

change?, Environmental Health Perspectives, v. 107, p. 

907–938.

Glassmeyer, S.T., Furlong, E.T., Kolpin, D.W., Cahill, J.D., 

Zaugg, S.D., Werner, S.L., Meyer, M.T., and Kryak D.D., 

2005, Transport of chemical and microbial compounds 

from known wastewater discharges: Potential for use as 

indicators of human fecal contamination, Environmental 

Science and Technology, v. 39, p. 5157–5169.

Halling-Sorensen, B., Nielsen, S.N., Lanzky, P.F., Ingerslev, F., 

Lutzhoft, H.C.H., and Jorgensen, S.E., 1998, Occurrence, 

fate, and effects of pharmaceutical substances in the 

environment–A review: Chemosphere, v. 36, p. 357–394.

Kolpin, D.W., Furlong, E.T., Meyer, M.T., Thurman, E.M., 

Zaugg, S.D., Barber, L.B., and Buxton H.T., 2002, 

Pharmaceuticals, hormones, and other organic wastewater 

contaminants in US streams, 1999–2000: A national 

reconnaissance, Environmental Science and Technology, 

v. 36, p. 1202–1211.

Stackleberg, P.E., Furlong, E.T., Meyer, M.T., Zaugg, S.D., 

Henderson, A.K., and Reissman, D.B., 2004, Persistence of 

pharmaceutical compounds and other organic wastewater 

contaminants in a conventional drinking-water treatment 

plant: Science of the Total Environment, v. 329, p. 99–113.

U.S. Geological Survey, variously dated, National field manual 

for the collection of water-quality data: U.S. Geological 

Survey Techniques of Water-Resources Investigations, book 

9, chaps. A1–A9, available online at http://pubs.water.usgs.

gov/twri9A.

References   
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For additional information write to: 

New York Water Science Center

U.S. Geological Survey

2045 Route 112, Bldg. 4

Coram, NY 11727

Information requests:

(518) 285-5602

or visit our Web site at:

http://ny.water.usgs.gov
Occurrence of Pharmaceuticals in Shallow Ground Water of Suffolk County, 

New York, 2002–2005

Benotti, Fisher, and Terracciano— —Open-File Report 2006-1297