Pesticides in Nursery Runoff:Pesticides in Nursery Runoff: Sources and Transport ProcessesSources and Transport Processes

Jay Gan Jay Gan

Dept. Environmental SciencesDept. Environmental Sciences

UC Riverside, CA 92521UC Riverside, CA 92521

jgan@mail.ucr.edujgan@mail.ucr.edu

909-787-2712909-787-2712

OutlineOutline

Nursery and pesticidesNursery and pesticides Current issuesCurrent issues How does it happen?How does it happen? Governing ProcessesGoverning Processes

Nursery in CANursery in CA(2001)(2001)

Production sales: $3.17 billion 10.6% of CA agricultural output 2nd among all CA agricultural products 21.3% of the U.S. nursery/floriculture total (11.9% for FL)

Retail sales $10.1 billion 1st in the U.S.

CA horticulture industry jobs 81,011 jobs in production 87,856 jobs in retailing

CA Nursery IndustryCA Nursery Industry

Total CA Nursery/Floral Production: $3.2 billion(2001)

Woody, decidousEvergreen 26%

Bedding plants 15%

Non- Ornamentals 19%

Potted plantsFlowering foliage 20%

Misc. 8%

Floral 12%

CA Nursery IndustryCA Nursery Industry

Total CA Retail Sales: $10.1 billion(2001)

HardwareHome centers$3,576 mil

Garden centersFarmsNurseries$2,859 mil

Chain storesWarehouses$2,757 mil

Florists$988 mil

CA Nursery IndustryCA Nursery Industry

Total Sales Composition (2001)

Lawn furnitureAccessoriesTree trim20.8%

ChemicalsFertilizers24.8%Green goods

26.0%

EquipmentTools28.4%

CA’s Top 10 Nursery, Flower and Foliage

Producing CountiesCounty Production (mil) Share of state

San Diego 855 27

Ventura 223 7.4

Orange 219 6.9

Monterey 179 5.6

Los Angeles 172 5.4

Santa Clara 150 4.7

Riverside 138 4.4

San Mateo 137 4.3

Santa Barbara 131 4.1

Kern 114 3.6

Total 2,319 73.45%

Nurseries & PesticidesNurseries & Pesticides

Pesticide UsesPesticide Uses Agricultural cropsAgricultural crops Home lawns/gardensHome lawns/gardens Structural/indoor pest controlStructural/indoor pest control NurseriesNurseries RoadsideRoadside ParksParks

Pesticide Use in California by SectorsPesticide Use in California by Sectors(million lbs)(million lbs)

Year Production Agriculture

Postharvest Fumigation

Structural Pest

Control

Landscape Maintenance

All Others

Total Pounds

1993 172 1.7 4.7 1.3 7.8 188 1994 175 2.0 5.2 1.3 7.4 191 1995 188 3.8 4.8 1.4 7.6 205 1996 182 1.8 4.7 1.3 7.6 197 1997 190 1.6 5.2 1.2 6.9 205 1998 199 1.7 5.9 1.4 6.8 214 1999 186 1.9 5.4 1.3 7.6 203 2000 172 2.1 5.2 1.4 6.7 187 2001 137 1.4 4.9 1.3 6.2 151 2002 157 1.9 5.5 1.4 6.8 172

Trend of Pesticide Use TotalTrend of Pesticide Use Total

0

50

100

150

200

250

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

Active In

gred

ients (m

il lbs)

Top Ten in CaliforniaTop Ten in California

2001 1999 2000 Pesticide Mil lbs % Mil lbs % Mil lbs % Sulfur 47.1 31.2 68.6 33.8 62.9 33.5 Petroleum oil 15.4 10.2 20.1 9.9 19.8 10.6 Metam sodium 11.3 7.5 16.8 8.3 12.8 6.8 Methyl bromide 6.6 4.4 15.2 7.5 10.9 5.8 Copper sulfate 3.4 2.3 3.8 1.9 4.9 2.6 Glyphosate 4.4 2.9 4.3 2.1 4.6 2.5 1,3-D 4.0 2.6 3.1 1.5 4.4 2.3 Mineral oil 3.6 2.4 4.7 2.3 4.2 2.2 Chloropicrin 4.3 2.8 3.6 1.8 3.8 2.0 Copper Hydroxide 2.6 1.7 3.5 1.7 3.3 1.8 Total 102.7 68.0 143.7 70.8 131.6 70.1

Use Trend of “Reproductive Toxic” Use Trend of “Reproductive Toxic” Pesticides in CAPesticides in CA

Reproductive Toxic ProductsReproductive Toxic Products

Major Compounds 2000 Arsenic pentoxide 91,267 Benomyl 118,601 Bromoxynil octanoate 116,125 Cyanazine 50,468 Eptc 323,254 Linuron 65,511 Metam-sodium 12,844,344 Methyl bromide 10,862,836 Myclobutanil 96,139 Oxydemeton-methyl 110,495 Propargite 1,306,767 Thiophanate-methyl 67,738 Grand Total 26,227,436

Use Trend of Carcinogenic Use Trend of Carcinogenic Pesticides in CAPesticides in CA

Carcinogenic PesticidesCarcinogenic Pesticides

ACTIVE INGREDIENT 2000 1,3-dichloropropene 4,440,928 Arsenic pentoxide 91,267 Captan 642,755 Chlorothalonil 679,746 Chromic acid 128,642 Iprodione 422,158 Mancozeb 611,197 Maneb 1,203,322 Metam-sodium 12,844,344 Propargite 1,306,767 Propylene oxide 118,381 Propyzamide 101,684 Grand total 22,889,829

Use Trend of Cholinesterase Use Trend of Cholinesterase Inhibiting Pesticides in CAInhibiting Pesticides in CA

Cholinesterase-Inhibiting PesticidesCholinesterase-Inhibiting Pesticides

ACTIVE INGREDIENT 2000 ACTIVE INGREDIENT 2000 Acephate 283,284 Methamidophos 76,865 Aldicarb 329,431 Methidathion 98,129 Azinphos methyl 185,055 Methomyl 550,591 Bensulide 217,111 Methyl parathion 75,169 Carbaryl 364,968 Molinate 1,025,786 Carbofuran 132,427 Naled 255,410 Chlorpyrifos 2,041,815 Oxamyl 137,989 Diazinon 1,053,407 Oxydemeton-methyl 110,495 Dimethoate 397,177 Pebulate 160,018 Eptc 323,254 Phorate 87,974 Ethephon 734,792 Phosmet 583,116 Fenamiphos 104,505 S,s,s-tributyl

phosphorotrithioate 399,706

Malathion 489,650 Thiobencarb 1,007,249

Use Trend of Groundwater-Risk Use Trend of Groundwater-Risk Pesticides in CAPesticides in CA

Groundwater-risk PesticidesGroundwater-risk Pesticides

ACTIVE INGREDIENT 2000 Atrazine 55,284 Atrazine, other related 2,952 Bentazon, sodium salt 1,210 Bromacil 67,753 Bromacil, lithium salt 4,478 Diuron 1,342,871 Norflurazon 257,651 Simazine 700,588 Grand Total 2,432,815

Surface water-Risk Pesticides

Not human safety concern !Not human safety concern ! Aquatic toxicity:Aquatic toxicity:

Organophosphate insecticides Organophosphate insecticides

(e.g., Dusban, diazinon)(e.g., Dusban, diazinon) Carbamate insecticides Carbamate insecticides

(e.g., carbaryl)(e.g., carbaryl) Synthetic pyrethroids Synthetic pyrethroids

(e.g., cyfluthrin, permethrin, …)(e.g., cyfluthrin, permethrin, …)

Mayfly Procloeon

Midge Chironomus

Most Used Nursery Pesticides

(San Diego County, 2002)Greenhouse Containers

Chemical Amount (lb)

Acephate 759

Chlorpyrifos 252

Daminozide 864

Diazinon 402

Fosetyl-Al 634

Glyphosate 964

Iprodione 468

Malathion 361

Mancozeb 562

Methyl bromide 1476

Potash soap 1425

Petroleum products 1449

Thiophanate-methyl 2202Source: CDPR

Most Used Nursery Pesticides

(San Diego County, 2002)Outdoor Containers

Chemical Amount (lb)

Acephate 1405

Chlorothalonil 1539

Chlorpyrifos 379

Daminozide 1240

Diazinon 226

Fosetyl-Al 1202

Glyphosate 9730

Iprodione 676

Malathion 1361

Mancozeb 1459

Methyl bromide 1546

Potash soap 1298

Petroleum products 6724

Thiophanate-methyl 2163 Source: CDPR

Aquatic Toxic Insecticides

(San Diego County, 2002)

Greenhouse ContainersChemical Amount (lb)

Bifenthrin 18

Chlorpyrifos 252

Cyfluthrin 12

Diazinon 402

Fenpropathrin 23

Malathion 361

Methiocarb 112

Permethrin 119

Source: CDPR

Aquatic Toxic Insecticides

(San Diego County, 2002)

Outdoor ContainersChemical Amount (lb)

Bifenthrin 60

Carbaryl 199

Chlorpyrifos 380

Cyfluthrin 35

Deltamethrin 12

Diazinon 226

Fenpropathrin 87

Malathion 1365

Methiocarb 22

Permethrin 217

Source: CDPR

Water Quality IssuesWater Quality Issues

Ground water issuesGround water issues Surface water issuesSurface water issues

TMDLsTMDLs TMDL examplesTMDL examples

Groundwater IssuesGroundwater Issues

TheThe CA Picture (CDPR, CWRCB)CA Picture (CDPR, CWRCB) 324 of 3,165 wells in year 2000324 of 3,165 wells in year 2000 84 verified detections84 verified detections From previous use (fumigants)From previous use (fumigants)

• DBCP, EDB, 1,2-DDBCP, EDB, 1,2-D From existing use (herbicides): From existing use (herbicides):

• Simazine, Simazine, ACETACET (from simazine or atrazine), (from simazine or atrazine), DACTDACT, norflurazon, bromacil, diuron, atrazine, , norflurazon, bromacil, diuron, atrazine, deethyl atrazinedeethyl atrazine

Distribution of Verified Detections

Surface Water Quality IssuesSurface Water Quality Issues

Urban surface water quality issuesUrban surface water quality issues Pesticide detections in most streamsPesticide detections in most streams

• 99% streams with 1 pesticide99% streams with 1 pesticide• 70% streams with 70% streams with 5 pesticides 5 pesticides

Sustained insecticide levelsSustained insecticide levels Harmful to aquatic organismsHarmful to aquatic organisms

• Beneficial useBeneficial use TMDLs for many streamsTMDLs for many streams

• The The newnew rule! rule!

What is TMDL?What is TMDL? CWA 303(d)CWA 303(d) States to make list of “impaired” watersStates to make list of “impaired” waters Develop TMDLs for the listed watersDevelop TMDLs for the listed waters TMDLs to account for all pollutants and all sources, TMDLs to account for all pollutants and all sources, TMDL includes non-point sources, e.g., urban and TMDL includes non-point sources, e.g., urban and

agricultural runoffsagricultural runoffs Develop implementation plans (Basin Plans or Water Develop implementation plans (Basin Plans or Water

Quality Control Plans in CA)Quality Control Plans in CA)

California:California: RWQCBsRWQCBs 800 TMDLs in total800 TMDLs in total 120 TMDLs in progress120 TMDLs in progress Amend the Basin Plan by Amend the Basin Plan by

incorporating TMDLsincorporating TMDLs

TMDL Elements:TMDL Elements: Problem statementProblem statement Numeric targetsNumeric targets Source analysisSource analysis AllocationsAllocations Implementation planImplementation plan Linkage analysisLinkage analysis Monitoring/Re-evaluationMonitoring/Re-evaluation Margin of safetyMargin of safety

High priority TMDLs in CA

Pollutant Total %

Pesticides 125 18

Metals/trace elements 118 17

Sediment 114 16.4

Other organics 95 13.7

Nutrients 67 9.6

Caliform/pathogens 45 6.5

Ammonia 22 3.2

Other 108 13.6

Total 694 100

High priority pesticide TMDLs in CA

Pesticide Total

DDT 76

Chlordane 15

Diazinon 9

Chlorpyrifos 6

Endosulfan 9

Unspecified 10

Total 125

San Diego Creek Pesticide TMDLsSan Diego Creek Pesticide TMDLs

Diazinon:Diazinon: 200-455 ppt 200-455 ppt 50 ppt 50 ppt 300-900% reduction!300-900% reduction!

ChlorpyrifosChlorpyrifos:: 87-111 ppt 87-111 ppt 14 ppt 14 ppt 600-800% reduction!600-800% reduction!

Legacy pesticides:Legacy pesticides: DDT, chlordane,…DDT, chlordane,…

Urban use is the No.1 source!Urban use is the No.1 source!

San Diego Creek Pesticide TMDLsSan Diego Creek Pesticide TMDLs

Table 1. Proposed Water-Quality Criteria for Diazinon and Chlorpyrifos

 Acute

(ppt) Chronic

(ppt) Ceriodaphnia

LC50

Diazinon 80 50 450

Chlorpyrifos 20 14 80

Reported and Estimated Diazinon UseOrange County 1999: Total = 54,048 lbs ai

Nursery (2%)

Other1%

Agriculture (1%)

Estimated Residential55%

Structural41%

How Does It Happen?How Does It Happen?

Storm water runoffStorm water runoff Irrigation runoffIrrigation runoff

Leaching through containers?Leaching through containers? Planting media spills?Planting media spills? Runoff + planting mediaRunoff + planting media

= pesticide runoff?= pesticide runoff?

IrrigationIrrigation

Nursery RunoffNursery Runoff

Runoff!

Runoff Driven:

Storm runoff Over-irrigation

Planting MediaPlanting Media

Dump

Shade HousesOutdoor

Container Area

Outdoor Container

Area

OFFICE

DOCKParking Lot

ENTRANCE

Shade Houses

Shade Houses

Outdoor Container Area

Shade Houses

Outdoor Container

Area

Outdoor Container

Area

Propagation

Propagation

Outdoor Container

Area

Shade House

Greenhouses Greenhouses

Potting AreaBifenthrin

Incorporation

Shop

Fertilizer Storage

PondChannel

Vegetative Filter

1

23

4

6

5

7

8

9

10

11

12

1314

1516

17

1819

20

Step 1: Scrap off surface soilStep 2: Estimate potting mix contentStep 3: Analyze pesticidesStep 4: Correlation

 Sample

Concentration (µg/kg)

Potting mix †Bifenthrin cis-Permethrin trans-Permethrin

1 3,971 373 4,625 1,194 53 13 80%

2 306 4 658 240 70 2 20%

3 344 17 1,556 322 178 94 5%

4 109 13 471 396 18 5 1%

5 163 18 521 96 58 6 <1%

6 275 81 5,948 651 1,478 43 50%

7 307 55 71 124 243 28 10%

8 17,440 436 631 831 642 1,085 100%

9 163 123 290 138 17 9 5%

10 125 6 113 101 23 9 1%

11 2,470 451 1,697 369 0 0 100%

12 389 17 387 137 24 2 1%

13 1,309 24 753 201 21 9 20%

14 852 19 1,535 506 16 2 15%

15 430 33 455 89 18 3 1%

16 3,055 211 5,115 1,669 80 139 50%

17 353 26 1,613 765 163 12 80%

18 95 7 238 21 27 3 1%

19 303 10 587 184 48 5 20%

20 305 25 178 39 35 1 1%

Pesticides in Spilled Potting MixPesticides in Spilled Potting Mix

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

1 3 5 7 9 11 13 15 17 19

Bifenthrin

Potting mix%

Loose Potting MixLoose Potting Mix

Governing ProcessesGoverning Processes

DegradationDegradation ChemicalChemical MicrobialMicrobial

AdsorptionAdsorption Leaching PotentialLeaching Potential Runoff PotentialRunoff Potential

Transport after applicationTransport after application

Degradation in SoilDegradation in Soil

What is “degradation”?What is “degradation”? Structural changes caused by chemical and/or Structural changes caused by chemical and/or

microbial reactionsmicrobial reactions Desirable environmentallyDesirable environmentally Pesticide-dependentPesticide-dependent Vary in different soil typesVary in different soil types Measured by persistence or “half-life” TMeasured by persistence or “half-life” T1/21/2

Long “half-life” = problemsLong “half-life” = problems• TT1/21/2 = leaching potential = leaching potential • TT1/21/2 = runoff potential = runoff potential

Pesticide degradation in soilPesticide degradation in soil

T1/2

What Causes Degradation?What Causes Degradation?

Chemical reactionsChemical reactions Hydrolysis (OPs, carbamates, etc.) – pH sensitiveHydrolysis (OPs, carbamates, etc.) – pH sensitive Photolysis – by UV, near the surfacePhotolysis – by UV, near the surface Oxidation – reduction by soil chemical speciesOxidation – reduction by soil chemical species Nucleophilic attacks by soil nucleophilesNucleophilic attacks by soil nucleophiles

Pesticide dependentPesticide dependent Soil dependentSoil dependent

What Causes Degradation?What Causes Degradation?

Microbial transformationsMicrobial transformations Biodegradation – bacteria use pesticides as “food”Biodegradation – bacteria use pesticides as “food” Cometabolism –degradation by “accident”Cometabolism –degradation by “accident” Enzyme-based transformationsEnzyme-based transformations

Pesticide dependentPesticide dependent Soil dependentSoil dependent

• Microbial ecologyMicrobial ecology• Organic matter plays a big roleOrganic matter plays a big role

Persistence

Risk

Adsorption in SoilAdsorption in Soil

What is “adsorption”?What is “adsorption”? Retention of pesticides by soilRetention of pesticides by soil Pesticide dependent Pesticide dependent Soil dependent Soil dependent

• Organic matter content Organic matter content , adsorption , adsorption

Weak adsorption + long persistence Weak adsorption + long persistence worst for worst for ground waterground water

Adsorption Adsorption = runoff in water = runoff in water Adsorption Adsorption = runoff with soil = runoff with soil

Adsorption Coefficient Adsorption Coefficient

KKdd

Adsorbed concentration / dissolved concentrationAdsorbed concentration / dissolved concentration

KKdd = = CCss / / CCww

KKdd = strong adsorption = strong adsorption

KKococ

KKoc oc = K= Kdd / OC (%) / OC (%) Adsorption is proportional to soil OC%Adsorption is proportional to soil OC%

KKococ < 100, weakly adsorbing < 100, weakly adsorbing KKococ > 1000, strongly adsorbing > 1000, strongly adsorbing

PesticideWise Searchable Webpages

www.pw.ucr.edu

Leaching PotentialLeaching Potential

What is leaching?What is leaching? Ability of pesticides to move through soil to reach Ability of pesticides to move through soil to reach

groundwatergroundwater

High leaching potentialHigh leaching potential Weak adsorptionWeak adsorption Long persistenceLong persistence

Shallow groundwater tableShallow groundwater table Active water movementActive water movement Sandy textureSandy texture

Leaching and AdsorptionLeaching and Adsorption

Retardation factor:Retardation factor: Reflect difficulty in moving with waterReflect difficulty in moving with water As As RR increases, rate of movement decreases increases, rate of movement decreases As As KKdd increases, rate of movement quickly increases, rate of movement quickly

decreasesdecreases

dbK

R 1

GUS IndexGUS Index

““GUS”GUS” Groundwater Ubiquity ScoreGroundwater Ubiquity Score

GUS = GUS = loglog((TT1/21/2) * (4 – ) * (4 – loglog((KKococ))))

Leaching riskLeaching risk Gus > 2.8: high leaching riskGus > 2.8: high leaching risk Gus < 1.8: low leaching riskGus < 1.8: low leaching risk 1.8 < GUS < 2.8: intermediate leaching risk1.8 < GUS < 2.8: intermediate leaching risk

Groundwater-risk PesticidesGroundwater-risk Pesticides

Pesticide Koc T1/2 (day)

GUS?

Atrazine 100 60 3.4 Bentazon, sodium salt 34 20 3.2 Bromacil 32 60 4.4 Diuron 480 90 2.6 Norflurazon 600 90 2.4 Simazine 130 60 3.4

Runoff PotentialRunoff Potential

Move in waterMove in water Diazinon, chlorpyrifos, many herbicidesDiazinon, chlorpyrifos, many herbicides

Move with loose soil particlesMove with loose soil particles synthetic pyrethroidssynthetic pyrethroids

Water flow

DOC-

DOC-

RunoffRunoff

Long persistence + weak adsorptionLong persistence + weak adsorption high runoff potentialhigh runoff potential

Long persistence + strong adsorptionLong persistence + strong adsorption intermediate runoff potentialintermediate runoff potential

Short persistence + weak adsorptionShort persistence + weak adsorption TransientTransient

Short persistence + strong adsorptionShort persistence + strong adsorption Harmless Harmless

Contact Info:Contact Info:Jay Gan Jay Gan

Dept. Environmental SciencesDept. Environmental Sciences

UC Riverside, CA 92521UC Riverside, CA 92521

jgan@mail.ucr.edujgan@mail.ucr.edu

(909) 787-2712(909) 787-2712

California Department of Food & AgricultureCalifornia Department of Pesticide RegulationCalifornia SWRCBSanta Ana RWQCBEl Modeno Gardens NurseryFMC Inc.