1

Sedimentation Pond and Plant Filter Strip in Mitigating RIFA Insecticide Runoff at el modeno

Gardens

Dave Kim, Johanna Walters, Kean S. GohDepartment of Pesticide RegulationJohn Kabashima, Darren Haver

UC Cooperative ExtensionToby Mancini

el modeno GardensAugust 15, 2001

Outline

• Introduction • Runoff Monitoring • Runoff Mitigation • Conclusions

The Insecticides

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

Insecticide Factors

• Vapor Pressure (mm Hg)• Water Solubility (ppm, mg/L)• Soil Adsorption Coefficient (Koc)• Field Dissipation (t1/2, days)

Water Solubility (ppm)

0

10

20

30

40

50

60

Talst

ar

Durs

ban

Diaz

inon

Awar

d

Amdr

o

Dista

nce

2

Soil Adsorption Coefficient

0

50

100

150

200

250

Talstar Dursban Diazinon Award Amdro Distance

Field Dissipation Half-Life (Days)

0

20

40

60

80

100

120

140

160

Talstar Dursban Diazinon Award Amdro Distance

Aquatic Toxicity

00.20.40.60.8

11.21.41.61.8

Aba

mec

tin

Bife

nthr

in

Chl

orpy

rifo

s

Dia

zino

n

Feno

xyca

rb

Hyd

ram

ethy

lnon

Pyri

prox

yfen

R. Trout D. magna

Offsite Movements

• Spray drift– primary, secondary

• Runoff–dissolved in water –adsorbed to soil particles and organic

materials

Runoff Monitoring

3

El Modeno Outflow

0

1

2

3

4

5

6

7

8

9

Jun

-99

Sep

-99

Oct

-99

Dec

-99

Jan

-00

Feb

-00

Mar

-00

Ap

r-0

0

May

-00

Jun

-00

Jul-

00

Au

g-0

0

Sep

-00

Sep

-00

Oct

-00

Oct

-00

No

v-0

0

No

v-0

0

Dec

-00

Dec

-00

Jan

-01

Jan

-01

Feb

-01

Mar

-01

Mar

-01

May

-01

May

-01

Jun

-01

Con

cent

rati

on (

ppb)

bifenthrinchlorpyrifosdiazinondimethoatemalathionmethidathionm. parathionfonofos

el modeno Gardens

0123456789

10

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

(%

)

diazinonchlorpyrifosfenoxycarbbifenthrin% mortality

San Diego Creek

0

.5

1M

ar-9

9A

pr-9

9

Ma

y-9

9Ju

n-9

9

Sep-

99

Oct

-99

Dec

-99

Jan-

00

Feb

-00

Mar

-00

Apr

-00

Ma

y-0

0Ju

n-0

0

Jul-

00

Aug

-00

Sep-

00

Oct

-00

Nov

-00

Dec

-00

Jan-

01

Feb

-01

Mar

-01

Month

chlorpyrifosdiazinondimethoatefonofosmalathionbifenthrin

San Diego Creek

0

1

2

Mar

-99

Apr-

99

May

-99

Jun

-99

Sep

-99

Oct

-99

Dec

-99

Jan

-00

Feb

-00

Mar

-00

Apr-

00

May

-00

Jun

-00

Jul-

00

Au

g-0

0S

ep-0

0O

ct-0

0N

ov-0

0D

ec-0

0Ja

n-0

1F

eb-0

1M

ar-0

1

Co

nce

ntr

ati

on

(p

pb

)

0102030405060708090100

Mo

rta

lity

of

C. d

ub

ia (

%)

malathionfonofosdimethoatediazinonchlorpyrifos% mortality

Mitigation

4

Prevention & MitigationInsecticide & Application Irrigation ManagementWater RecoveryHolding Pond Buffer Strip

Bifenthrin Concentrations in Filter Strip

0

0.5

1

1.5

2

2.5

3

3.5

Jun

-00

Jul-

00

Aug

-00

Sep-

00

Sep-

00

Oct

-00

Oct

-00

Nov

-00

Nov

-00

Dec

-00

Dec

-00

Jan-

01

Jan-

01

Mar

-01

Mar

-01

May

-01

May

-01

Jun

-01

Co

ncen

tra

tio

n (p

pb

)

inflowoutflo

5

Chlorpyrifos Concentrations in Filter Strip

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Jun

- 00

Jul -

00

Aug

-00

Sep

-00

Sep

-00

Oct

-00

Oct

- 00

Nov

- 00

Nov

- 00

Dec

-00

Dec

-00

Jan-

01

Jan-

01

Mar

-01

Mar

-01

May

- 01

May

- 01

Jun

- 01

Co

nce

ntr

ati

on

(p

pb

)

inflowoutflow

Diazinon Concentrations in Filter Strip

0

0.05

0.1

0.15

0.2

0.25

Jun

-00

Jul-

00

Aug

-00

Sep

-00

Sep

-00

Oct

-00

Oct

-00

Nov

-00

Nov

-00

Dec

-00

Dec

-00

Jan-

01

Jan-

01

Mar

-01

Mar

-01

May

-01

May

-01

Jun

-01

Co

nce

ntr

ati

on

(p

pb

)

inflowoutflow

Malathion Concentrations in Filter Strip

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Jun

-00

Jul -

0 0

Au g

-00

Sep

-00

Sep

-00

Oct

-00

Oct

-00

Nov

-00

Nov

-00

Dec

-00

Dec

-00

Jan-

01

Jan-

01

Mar

-01

Ma r

-01

Ma y

-01

May

-01

Jun

-01

Co

nce

ntr

ati

on

s (p

pb

)

inflowoutflow

Sep-00Basin #1

Oct-00Basin #1

Sep-00Basin #2

Oct-00Basin #2

Sep-00Basin #3

Oct-00Basin #3

diazinonchlorpyrifos

bifenthrin0

50

100

150

200

250

300

Con

cent

ratio

n (p

pb)

sample location

Filter Strip Sediment Samples 2000

Feb-01Basin #2

Mar-01Basin #2

Feb-01Basin #7

Mar-01Basin #7

diazinon

bifenthrin0

400

800

1200

1600

Concentration (ppb)

Sample location

Filter Strip Sediment Samples 2001

Polyacrylamide (PAM)

6

50.80

%49

.90%

57.06

%17

.99%

64.1

6%21

.05%

0

0.2

0.4

0.6

0.8

1

1.2

1.4

% reduction

Bifenthrin OutBifenthrin In

PAM

0 1 2 3 4 5

Dia

zin

on

Ou

tD

iazi

no

n In

Bife

nth

rin

Ou

tB

ifen

thri

n In

00.20.40.60.8

11.21.4

Diazinon OutDiazinon InBifenthrin OutBifenthrin In

Conclusions

Runoff

• Bifenthrin, diazinon, malathion• Bifenthrin high>3 ppb, currently <1 ppb• Diazinon high>8 ppb, currently trace• Peaks at rain runoff• Toxic to C. dubia

Mitigation Reduction in Water Concentration• Bifenthrin 52%• Chlorpyrifos 61%• Diazinon –13%• Malathion 31%

Sediments

• Bifenthrin– Increased through time

• 200 – 1400 ppb– Increased downstream basin

• 150 –250 ppb • 800 – 1200 ppb

• Chlorpyrifos <80 ppb• Diazinon none detected

7

Acknowledgments

California Dept of Food and Agriculture Center for Analytical Chemistry

UC Cooperative Extensionel modeno Gardens

Department of Fish and GameOrange County Dept of Agriculture

Regional Water Quality Control Board

www.cdpr.ca.gov/docs/rifa