J FMAMJ J ASOND

0

1

2

3

4

5

6

7

8

9

10

0

0.2

0.4

0.6

0.8

1

1.2

TOTAL PESTICIDE CONCENTRATION

PER SAMPLE, IN MICROGRAMS

PER LITER

NUMBER OF SAMPLES

Introduction

From 1994 through 1996, the U.S. Geological Survey conducted

a study of pesticides in Canajoharie Creek as part of the National

Water Quality Assessment (NAWQA) program in the Hudson River

Basin. A primary objective of the NAWQA program is to describe

the status and trends in the quality of representative parts of the

Nation’s surface-water resources and to provide a scientific

understanding of the major natural and human factors that affect the

quality of these resources. This fact sheet (1) presents results of

pesticide analyses of samples collected from Canajoharie Creek,

which drains a 155 km2

 watershed in central New York, that is 66

percent agricultural land, and (2) illustrates the importance of

obtaining storm-runoff samples soon after pesticides are applied.

Canajoharie Creek was selected for study because (1) the

percentage of agricultural land in the watershed is typical of that

found within 20 km of the Mohawk River, the largest tributary to the

Hudson River (fig. 1), and (2) the occurrence of certain pesticides in

Canajoharie Creek is considered representative of pesticides found in

other agricultural watersheds in the Mohawk River subbasin. (Wall

and Phillips, 1996). ♦

Pesticide Sampling

Water samples collected from Canajoharie Creek were analyzed

for 47 pesticides (both herbicides and insecticides); a complete list is

given in Firda and others (1994). Herbicides are used to control

weeds in agricultural fields as well as on lawns, commercial land,

and other open areas in urban and residential settings; insecticides

are used to control insects in agricultural and urban settings.

Canajoharie Creek was sampled at one location (fig. 1) weekly

or monthly for pesticides from March 1994 through March 1996. It

was sampled eight times from June 7-11, 1996 during the first storm

runoff after pesticide application. The creek was sampled twice

during the previous two years (July 1, 1994 and June 3, 1995) under

similar runoff conditions. ♦

Results of Pesticide Sampling

Results from the 2 years of sampling are summarized in figure

2 and table 1. Most samples were collected during May, June, and

July, when pesticides commonly are applied to agricultural fields.

As expected, the total pesticide concentration per sample was

highest during June and July; it was higher in July than in all other

months because a sample collected on July 1, 1994, contained

higher concentrations of atrazine†, deethylatrazine (a breakdown

product of atrazine), metolachlor, and simazine than any other

sample collected during the 2-year period. Except for EPTC, the

†Use of trade, product, or firm names in this publication is for

descriptive purposes only and does not imply endorsement by the U.S.

Government.

Figure 2. Monthly pesticide sampling statistics – March 1994

through March 1996. Total pesticide concentration per sample

is calculated as the sum of all pesticide concentrations

detected for a given month divided by the number of samples

collected during that month.

FULTON CO.

MONTGOMERY CO. HERKIMER CO.

N

 River

SCHOHARIE CO.

Canajoharie

Fort Plain

Little Falls 

St. Johnsville Mohawk

Canajoharie Creek

Watershed

74°30'

43°

0

0 10 20

10 MILES

KILOMETERS

74°45'50"

42°52'30"

Base from U.S. Geological Survey

digital data 1:2,000,000, 1972

Detailed

Area MA

CT

VT

NY

Hudson R.

Basin

Hudson

River

Watershed boundary

Water

Forest land Other

Agricultural land

Sampling location

Urban, residential

 and built-up land

EXPLANATION

Pesticide Concentrations in Canajoharie

Creek, New York 1994-96

Figure 1. Land use and location of sampling site in Canajoharie

Creek watershed, New York
– Gary R. Wall and Patrick J. Phillips

0

1

2

3

4

5

6

7

8

9

10

0

50

100

150

200

250

0.001

0.01

0.1

1

10

20

.

NUMBER OF PESTICIDES DETECTED

PESTICIDE CONCENTRATION, IN

MICROGRAMS PER LITER

STREAMFLOW, IN CUBIC FEET PER SECOND

789 10 11

JUNE 1996

O Below Detection (<0.004 μg/L)

Atrazine

Pendimethalin

Streamflow

Number of Pesticides

. .

.

.

... .

January 1998 Fact Sheet FS 131-97

maximum concentrations of all pesticides, between March 1994 and

March 1996, occurred during periods of storm runoff in June or July.

Samples collected in June 1996 contained the highest observed

concentrations of atrazine, metolachlor, simazine, pendimethalin,

alachlor, and carbaryl (table 1) to date. Only two samples collected

during the 2-year period before June 1996 contained a pesticide

concentration above any health advisory level or maximum

contaminant level (MCL) (table 1) established by the U.S.

Environmental Protection Agency (1996). Five storm runoff samples

collected over 9.5 hours on June 10, 1996, exceeded the MCL for

atrazine. The absence of metribuzin and EPTC in samples collected on

June 10 was not surprising in that these pesticides had been detected in

only three samples in previous years. The absence of diazinon in the

June 1996 samples could reflect the time of year at which it is applied,

55 percent of the detections (6 samples) were during April and May,

and (or) a change in diazinon use in the watershed (73 percent of

detections were in 1994).

The calculated atrazine load (mass of atrazine passing the sampling

location) during a 14-hour period on June 10, 1996 was 1.0 kilogram, a

disproportionate amount compared to a load of 0.028 kilograms during

a 60 day low-flow period the previous year (June 12 to August 11,

1995). The number of samples collected from March 1994 through

March 1996 was insufficient for an accurate estimation of annual

For additional information contact:

Hudson River NAWQA Project Chief

U.S. Geological Survey

425 Jordan Road

Troy, NY 12180

This fact sheet and related information can be found

on the World Wide Web at: http://ny.usgs.gov

References Cited

Firda, G. D., Lumia, R., Murray, P. M., and Freeman, W. O., 1994, U.S.

Geological Survey Water Resources Data, Volume 1, NY-94-1, 488 p.

U.S. Environmental Protection Agency, 1996, Drinking Water

Regulations and Health Advisories: Environmental Protection

Agency, 822-B-96-002, 10 p.

Wall, G. R. and Phillips, P. J., 1996, Pesticides in Surface Waters of the

Hudson River Basin, New York and Adjacent States. U.S.

Geological Survey Fact Sheet, FS-238-96, 4p. ♦

pesticide loads, but the 14-hour load on June 10, 1996 probably

represented a significant part of the total annual load for 1996. ♦

Maximum

20

3.1

0.10

0.85

 –

 –

0.12

 –

0.061

0.048

0.008

Table 1. Concentrations of pesticides in water samples from Canajoharie Creek, New York

 [μg/L - micrograms per liter, na - data not available]

1

MCL - Maximum permissible level of a contaminant in water which is delivered to any user of a public water system;

 HA - Concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects over a lifetime of exposure.

Pesticide

Atrazine

Metolachlor

Deethylatrazine

Cyanazine

Diazinon

Metribuzin

Simazine

EPTC

Pendimethalin

Alachlor

Carbaryl

Median of

detections

0.040

0.019

0.015

0.022

0.009

0.027

0.013

0.004

0.035

0.002

–

Detection

limit

 (μg/L)

0.001

0.002

0.002

0.004

0.002

0.004

0.005

0.002

0.004

0.002

0.003

MCL/HA1

(μg/L)

3 / 3

na / 70

na / na

na / 1

na / 0.6

na / 100

4 / 4

na / na

na / na

2 / na

na / 700

Number

of

samples

40

40

40

41

34

41

41

40

41

41

41

Percentage of

samples with

detection

100

100

97.5

46.3

32.4

4.9

4.9

2.5

2.4

2.4

0

Maximum

4.3

1.3

0.22

2.1

0.035

0.033

0.018

0.004

0.035

0.002

–

Number

of

samples

8

8

8

8

8

8

8

8

8

8

8

Percentage of

samples with

detection

100

100

100

100

0

0

75.0

0

87.5

100

12.5

Median of

detections

3.2

0.535

0.036

0.400

 –

 –

0.028

 –

0.026

0.020

0.008

Concentration (μg/L) Concentration (μg/L)

March 1994 -March 1996 June 7-11, 1996

Figure 3. Select results of June 7-11, 1996 pesticide sampling