Pesticides in Nursery Pesticides in Nursery Runoff: Runoff: Sources and Transport Sources and Transport Processes Processes Jay Gan Jay Gan Dept. Environmental Sciences Dept. Environmental Sciences UC Riverside, CA 92521 UC Riverside, CA 92521 [email protected][email protected]909-787-2712 909-787-2712
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Pesticides in Nursery Runoff: Sources and Transport Processes
Pesticides in Nursery Runoff: Sources and Transport Processes. Jay Gan Dept. Environmental Sciences UC Riverside, CA 92521 [email protected] 909-787-2712. Outline. Nursery and pesticides Current issues How does it happen? Governing Processes. Nursery in CA (2001). Production sales: - PowerPoint PPT Presentation
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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 [email protected]@mail.ucr.edu
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 IndustryTotal 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 IndustryTotal 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 IndustryTotal 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 stateSan Diego 855 27Ventura 223 7.4Orange 219 6.9Monterey 179 5.6Los Angeles 172 5.4Santa Clara 150 4.7Riverside 138 4.4San Mateo 137 4.3Santa Barbara 131 4.1Kern 114 3.6Total 2,319 73.45%
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)
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:
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):
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
Transport after applicationTransport after application
Degradation in SoilDegradation in Soil What is “degradation”?What is “degradation”?
Structural changes caused by chemical and/or microbial Structural changes caused by chemical and/or microbial reactionsreactions
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
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
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
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
California Department of Food & AgricultureCalifornia Department of Pesticide RegulationCalifornia SWRCBSanta Ana RWQCBEl Modeno Gardens NurseryFMC Inc.