Pesticides

1. Pesticides and Water Quality

2. Objectives • Define groundwater and it’s characteristics. • Identify possible fates of pesticides in the environment. • List preventative measures applicators’ can use to protect water quality. • Identify the”how to” and importance of testing and protecting private water supplies.

3. Transpiration The Water Cycle Precipitation Evaporation

4. What is Groundwater? Soil Capillary Water Unsaturated Rock WaterTable Saturated Rock (Aquifer) Saturated Water

5. How Long Does it Take Rain Waterto Get to the Stream? Days Weeks Months Years On average – it takes about 6 to 12 months on a forested watershed.

6. The Watershed A completely cut experimental watershed in Central PA

7. Groundwater Moves! barn and feed lot Direction of ground water flow stream WHPA home and septic system Distribution and increased awareness of extension publications and resources?

8. Consequences of GW Contamination • Often impossible to clean, lasts for years

9. GW Contamination Factors: • Pesticide properties • Soil properties • Site conditions • Applicator practices

10. Pesticide Properties • Adsorptivity • Degradation Rate • Solubility • Volatility • Persistence

11. Pesticide PropertiesAdsorption • Attached to soil or organic matter. Groundwater Contamination Factors – Pesticide Properties

12. Pesticide PropertiesAbsorption • Uptake into plants or animals Groundwater Contamination Factors – Pesticide Properties

13. Pesticide PropertiesDegradation • Broken down into other chemicals like Carbon Dioxide and water. • Microbial degradation • Chemical degradation Groundwater Contamination Factors – Pesticide Properties

14. Pesticide PropertiesPhotodegradation • Broken down by sun Groundwater Contamination Factors – Pesticide Properties

15. Pesticide PropertiesSolubility Groundwater Contamination Factors – Pesticide Properties

16. Pesticide PropertiesVolitization • Conversion to gas Granular, flowable, and wettable powders – less susceptible to volatilization! Groundwater Contamination Factors – Pesticide Properties

17. Pesticide PropertiesPersistance Some pesticides remain in the ground longer than others Groundwater Contamination Factors – Pesticide Properties

18. Soil Properties • Soil Texture • Soil Structure • Soil Organic Matter Content • Soil Permeability Groundwater Contamination Factors – Soil Properties

19. Soil PropertiesTexture Groundwater Contamination Factors – Soil Properties

20. Soil PropertiesStructure Groundwater Contamination Factors – Soil Properties

21. Soil PropertiesOrganic Matter Groundwater Contamination Factors – Soil Properties

22. Soil PropertiesPermeability Groundwater Contamination Factors – Soil Properties

23. Site Conditions • Depth to groundwater • Geological Conditions • Climate and Irrigation Practices - Determining Leaching Potential - Runoff - Reducing Runoff - Soil Moisture Conditions Groundwater Contamination Factors – Site Conditions

24. Site ConditionsDepth to Groundwater Depth to groundwater is major factor! • Filtering • Soil Properties • Texture & Organic Matter • Application Events • Solubility Groundwater Contamination Factors – Site Conditions

25. Site ConditionsGeological Conditions Local Soil Properties Groundwater Contamination Factors – Site Conditions

26. Site ConditionsGeology of the Soil Groundwater Contamination Factors – Site Conditions

27. Site ConditionsClimate Groundwater Contamination Factors – Site Conditions

28. Site ConditionsClimate and Irrigation Practices Annual Rainfall Groundwater Contamination Factors – Site Conditions

29. 9 8 7 6 5 Inches of Water 4 3 2 1 0 Jan Mar May Jul Sep Nov Month Monthly Precipitation and Evapotranspiration in PA Evapotranspiration Precipitation Moisture Deficit Groundwater Recharge Moisture Surplus

30. Site ConditionsRunoff Carried by surface water • Factors • Scouting • Erodibility • Rain Amount • Cover Groundwater Contamination Factors – Site Conditions

31. Site ConditionsReducing Runoff • Pesticide Incorporation • Contour farming • Borders of untreated vegetation Groundwater Contamination Factors – Site Conditions

32. Applicator Management Practices • Use IPM to reduce pesticide use • Pesticide Handling • Mixing • Application • Storage • Disposal

33. Applicator Management PracticesIPM • Goal – Reduce Pesticide Use to Minimum Levels • Scouting • Timing of Application • Beneficial’s • Res. Var. • GMO’s Groundwater Contamination Factors – Applicator Management Practices

34. Applicator Management PracticesPesticide Handling • Mixing • Follow label instruction • Avoid or Contain Spills • Complications of Improper Handling Groundwater Contamination Factors – Applicator Management Practices

35. Applicator Management PracticesPesticide Handling • Application • Equipment checked and maintained • Chemigation • Irrigation Groundwater Contamination Factors – Applicator Management Practices

36. Applicator Management PracticesPesticide Handling • Storage • Follow standard practices – be mindful of movement of loose fluids • Keep in containers; away from water; dry well-ventilated location • Buy enough product for needs Groundwater Contamination Factors – Applicator Management Practices

37. Applicator Management PracticesPesticide Handling • Follow Label Recommendations • Triple Rinse Containers • Dikes • Chemsweep • Disposal Groundwater Contamination Factors – Applicator Management Practices

38. Determining Leaching Potential • Pesticide Properties - Low adsorptivity, Slow degradation, High solubility, Persistent • Soil Characteristics - High sand and gravel, Low organic matter • Site Conditions - Shallow depth to groundwater, High rainfall or irrigation • Management - Pesticide injection or incorporation into soil - Poor timing (heavy rain)

39. Preventative Measures • Identify vulnerability of soil • Consider where surface and groundwater are in relation to application • Know pesticides that may leach • Follow label directions • Apply at appropriate time • Measure properly and carefully

40. Preventative Measures (Continued) • Calibrate and maintain equipment • Avoid spills and back-siphoning • Direct application to target site • Leave buffer zones around sensitive areas • Dispose of pesticides properly (Triple Rinse) • Store pesticides safely

41. Preventative Measures (Continued) • Maintain records of pesticide usage • Avoid Over-application and Drift • Consider weather and runoff • Know and check your well • Use IPM – Apply Pesticides Only When Necessary! • Pesticide and Groundwater Advisory Statements

42. Health Effects of Groundwater Contamination • Factors • Chemical Toxicity • Duration of Exposure • Dose

43. Dose-Response Relationship • Risk of adverse health effects increases with level of exposure. Threshold?

44. Atrazine Sevin Furadan Chlordane Dursban Copper Bladex Extrazine Dacthal Diazinon Banvel Roundup Lindane Malathion Parathion Methoxychlor Gramoxone 2,4,5-T Common Agronomic Pesticides Detected

45. Units of Measure mg/L = ppm 1 drop in 116 soda cans µg/L = ppb 1 drop in 116,000 soda cans other special units

46. Health Effects of Groundwater ContaminationAgriculture nitrates pesticides coliform bacteria

47. Health Effects of Groundwater ContaminationPrivate Water Supplies Maintenance, Testing, Treatment and Protection are all voluntary!!!

48. Proper Well Construction • Divert surface water away from wellhead • Prevent insects and animals from getting • under the well cap “sanitary” well cap sloping ground casing to bedrock grout seal bedrock

49. EPA Drinking Water Standards Gives the “acceptable level” of pollutant in drinking water

50. Primary Standards (MCL)(maximum contaminant level) • health based • enforced (public systems) • examples: • coliform bacteria: <1/100 ml • nitrate: 45 mg/L • PCE: 5 µg/L • atrazine: 3 µg/L