Pesticides and their Degradation Products in Surface Water and ...

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Pesticides and their Degradation. Products in Surface Water and Ground. Water of the Mid-Atlantic Region. Jeffrey M Fisc
Pesticides and their Degradation Products in Surface Water and Ground Water of the Mid-Atlantic Region

Jeffrey M Fischer US Geological Survey Trenton NJ

Why study Pesticide Degradation Products? • When measured, degradation products are often detected more frequently than parent compounds. • Concentrations of pesticide degradates often exceed concentrations of parent compounds.

Sources of Data • Primarily National Water Quality Assessment Program (NAWQA) • State Programs • Cooperative studies

What analyze for? • Widely used pesticides and their degradation products. • 2-3 lab schedules, >150 compounds D elaw are R iver B asin Agricultural Pesticide U se, 1992 (usage greater than 25,000 pounds per year show n) 600,000

500,000

300,000

200,000

100,000

ID

E

EB

M O

M Y

AN M

YL _

BR

E N

ET H O

AZ I

TE O LI Y R

C

SI M

N R U N

L

ET H

H C

O

S R PY

R LO

C

LI

IF O

4_ D 2_

E YA

N

C

O

AZ I

N

ZE B

IL AN

AL O

N M

M

M

C

H

LO

G

R

O

TH

LY PH

O

S

TH

A

AT E

LI N

N TA IM E D N

H

AP C PE

LO R

IL O AL AC

E N AZ I AT R

H C

ET O LA

SU

LF

LO

U

R

R

0

M

Pounds Applied

400,000

Frequently Detected Pesticides Primarily discussing degradation products of: Detection frequencies vary seasonally Detections greater in streams than wells

• Triazine Herbicides • Acetalinide Herbicides • Few Other Pesticides

Herbicide Degradates in Streams Metolachlor degradates in the Schuylkill River

Not detected

Piedmont Valley & Ridge Glacial Fill

AZ AT R

INE DE E

L TH Y

AZ ATR

LD TH Y

E IS

O

P RO

PYL

INE

Long Island

50% 45% 40% 35% 30% 25% 20% 15% 10% 5% 0%

ME

AZ ATR

Piedmont Valley & Ridge Glacial Fill

Not detected

Percent Detection

DE E

INE

TO

H LAC

LO

R

M

O ET

L AC

HL

ES OR

A ME

TO

LA

L CH

OR

OA

Not detected

P e r c e n t D e te c tio n

Long Island

70% 60% 50% 40% 30% 20% 10% 0%

Geologic Differences • Time since applied • Age of water • Thickness of Unsaturated Zone? • Permeability? • Soil Properties?

Pesticide Concentrations in Streams and Domestic Wells • Degradate concentrations typically are equal to or greater than parents • Degradates have no drinking water standards, but sometimes approach MCL for parents. Concentration (ug/L)

Toxicity of Degradates

Other Recent Pesticide Sampling Frequently Detected Pesticides in Ground Water

• In surface water: Carbaryl,

Metalaxyl,

Fipronil sulfone

• Sampled Raritan and Delaware Rivers • 32 of 83 pesticides detected, including • 9 degradates

Metsulfuron, Im azethapyr, Acifluorfen, OIET

3,5-Dichloroaniline,

3-Ketocarbofuran,

• In ground water: Metolachlor,

Fenuron,

• Sampled 34 monitoring wells in Coastal Plain • 135 of 137 pesticides detected, including • 34 degradates Dieldrin,

Im idacloprid,

Prom eton,

Atrazine,

Caffeine, CIAT

CEAT

Sim azine,

0%

10%

20%

30%

40%

Percent Detection

50%

60%

Other Pesticide Degradates Fipronil

Desulfinyl fipronil Desulfinylfipronil amide Fipronil sulfide

Streams wells

Fipronil sulfone 0%

10%

20%

30%

40%

50%

60%

• Fipronil Maximum Parent concentrations • SW=0.020 ug/L; GW=0.100 ug/L

• Maximum Degradate concentrations • SW=0.013 ug/L; GW=0.194 ug/L

Summary • Pesticide degradation products are often detected more frequently than parent compounds. • Concentrations of pesticide degradates often exceed concentrations of parent compounds, especially in ground water. • Formation of degradation products is controlled by geologic and hydrologic conditions as well as chemical properties. • Degradation products have no standards for protection of humans or wildlife.