1

Concentration and Aquatic Toxicity of RIFA Insecticides and Other

Organophosphates in Surface WaterMarch 1999-June 2000

Dave Kim, Johanna Walters, Kean S. GohDepartment of Pesticide Regulation

September 14, 2000UC Riverside, CA

Outline

• Introduction • Monitoring • Irrigation Runoff vs. Storm Runoff • Urban vs. Nurseries• Regulatory Approach • Runoff mitigations• Conclusions

The Insecticides

• Bifenthrin (Talstar®)• Chlorpyrifos (Dursban®)• Fenoxycarb (Award®)• Hydramethylnon (Amdro®)• Pyriproxyfen (Distance®)• Diazinon

Aquatic Toxicity (LC50 ppb)

1.141.8170Malathion

na 400>325Pyriproxyfen

na 1140160Hydramethylnon

na4001600Fenoxycarb

0.510.962600Diazinon

0.131.73Chlorpyrifos

na0.160.15Bifenthrin

C. dubia D. magna

R. TroutChemical

San Joaquin Marsh Preserve

Newport Bay Ecological Reserve

2

Irrigation Runoff

Bee Canyon

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Jun-99

Sep-99

Oct-99

Dec-99

Jan-00

Feb-00

Mar-00

Apr-00

May-00

Jun-00

Month

Con

cent

rati

on (

ppb)

bifenthrinfenoxycarbchlorpyrifosdiazinonmalathion

Bee Canyon

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10

Jun-99Sep-99Oct-99 Dec-99

Jan-00Feb-00 Mar-00

Apr-00 May-00

Jun-00

Month

Con

cent

rati

on (

ppb)

0102030405060708090100

Mor

talit

y of

C. d

ubia

(%

)

diazinonchlorpyrifosfenoxycarbbifenthrin% mortality

Central Irvine/ Hines Channel

0

1

2

3

4

5

May-99

Jun-99

Sep-99

Oct-99

Dec-99

Jan-00

Feb-00

Mar-00

Apr-00

May-00

Jun-00

Month

Con

cent

rati

on (

ppb)

bifenthrinfenoxycarbchlorpyrifosdiazinondimethoatemalathion

Central Irvine/ Hines Channel

0

1

2

3

4

5

May-99

Jun-99

Sep-99

Oct-99

Dec-99

Jan-00

Feb-00

Mar-00

Apr-00

May-00

Jun-00

Month

Con

cent

rati

on (

ppb)

0102030405060708090100

Mor

talit

y of

C. d

ubia

(%

)

malathiondimethoatediazinonchlorpyrifosfenoxycarbbifenthrin% mortality

Bordier's

0

1

2

3

4

5

Jun-99

Sep-99

Oct-99

Dec-99

Jan-00

Feb-00

Mar-00

Apr-00

May-00

Jun-00

Con

cent

rati

on (

ppb)

bifenthrinchlorpyrifosdiazinonmalathion

3

San Diego Creek

0

1

2

Mar

-99

Apr

-99

May

-99

Jun-

99Se

p-99

Oct

-99

Dec

-99

Jan-

00Fe

b-00

Mar

-00

Apr

-00

May

-00

Jun-

00

Con

cen

trat

ion

(p

pb

) chlorpyrifosdiazinondimethoatemalathion

San Diego Creek

0

1

2

Mar

-99

Apr

-99

May

-99

Jun-

99Se

p-99

Oct

-99

Dec

-99

Jan-

00Fe

b-00

Mar

-00

Apr

-00

May

-00

Jun-

00

Con

cen

trat

ion

(p

pb

)

0102030405060708090100

Mor

tali

ty o

f C. d

ubia

(%

)

malathiondimethoatediazinonchlorpyrifos% mortality

Westcliff Park

0

1

2

3

Dec-99 Jan-00 Feb-00 Apr-00 May-00 Jun-00

Con

cent

ratio

n (p

pb)

chlorpyrifos

diazinon

malathion

Westcliff Park

0

1

2

3

Dec-99 Jan-00 Feb-00 Apr-00 May-00 Jun-00

Con

cent

rati

on (

ppb)

0102030405060708090100

Mor

talit

y of

C. d

ubia

(%

)

malathion

diazinon

chlorpyrifos

% mortality

Storm Runoff

Marshburn Slough

0

0.5

1

1.5

1 2 3 4 5 6

Sampling Interval

Conc

entra

tion (

ppb)

0

1

2

3

4

5

6

Bifen

thrin

conc

entra

tion

(ppb)

feno xycarb hydramethylno n pyripro xyfenchlo pyrifo s diazino n mala thio n

bifenthrin

4

San Diego Creek

0

0.5

1

1.5

1 2 3 4 5 6

Sampling Interval

Conc

entra

tion (

ppb)

0

1

2

3

4

5

6

feno xycarb hydramethylno n pyripro xyfenchlo pyrifo s diazino n mala thio n

bifenthrin

Westcliff Park

0

0.5

1

1.5

1 2 3 4 5 6

Sampling Interval

Conc

entra

tion (

ppb)

0

1

2

3

4

5

6

feno xycarb hydramethylno n pyripro xyfenchlo pyrifo s diazino n mala thio n

bifenthrin

Regulatory MAA

• Preventive (outreach and education)• Self-regulatory (voluntary programs)• Regulatory (DPR)• Regulatory (Federal and Regional Boards)

Mitigation

Application Runoff

5

6

Canna Filter Strip (June 2000)

00.10.20.30.40.50.60.70.80.9

bife

nthr

in

diaz

inon

met

hida

thio

n

Co

nce

ntr

atio

n (p

pb

)

Inflow Outflow

Conclusions

Detections: Irrigation Runoff

• Single detect: hydramethylnon, pyriproxyfen

• Nursery: Bifenthrin, Diazinon, Chlorpyrifos, Malathion, Dimethoate <8 ppb

• Urban: Diazinon, Malathion, Chlorpyrifos, Dimethoate <1.5 ppb

Detections: Storm Runoff

• Nursery–bifenthrin, diazinon, malathion,

chlorpyrifos, fenoxycarb <6 ppb• Urban

–diazinon, malathion, chlorpyrifos <1.5 ppb

Toxicity: Irrigation Runoff• Nursery sites:

– 18: Bifenthrin, Diazinon, Chlorpyrifos, Malathion– 1 unknown– 2 non toxic

• Urban and integrated sites:– 27:Diazinon, Malathion, Chlorpyrifos – 27 unknown – 21 non toxic

7

Toxicity: Storm Runoff

• Nursery– All 18 samples 100% mortality

• Bifenthrin, Diazinon, Malathion, Chlorpyrifos

• Urban– All 18 samples 100% mortality

• Diazinon, Malathion, Chlorpyrifos • Unknown

Prevention & MitigationInsecticide Application Irrigation ManagementWater RecoveryHolding Pond Buffer Strip

Acknowledgments

California Dept of Food and Agriculture Center for Analytical Chemistry Department of Fish and Game

Orange County Dept of AgricultureRegional Water Quality Control Board

UC Cooperative ExtensionBordiers Nursery

el modeno GardensHines Nursery