Pesticides

1
Pesticides
and
Water Quality
2
Objectives

• Define groundwater and its characteristics.
• Identify possible fates of pesticides in the
  environment.
• List preventative measures applicators can use
  to protect water quality.
• Identify thehow 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
Water Table
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 Properties Adsorption

• 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 Conditions Geological 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
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 Conditions Reducing 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
• Beneficials
• Res. Var.
• GMOs

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

• Disposal

• Follow Label Recommendations
• Triple Rinse Containers
• Dikes
• Chemsweep

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
Common Agronomic Pesticides Detected

• Atrazine
• Sevin
• Furadan
• Chlordane
• Dursban
• Copper
• Bladex
• Extrazine
• Dacthal

• Diazinon
• Banvel
• Roundup
• Lindane
• Malathion
• Parathion
• Methoxychlor
• Gramoxone
• 2,4,5-T

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 Contamination
Agriculture
nitrates pesticides coliform bacteria
47
Health Effects of Groundwater Contamination
Private 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
grout seal
casing to bedrock
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 lt1/100 ml
• nitrate 45 mg/L
• PCE 5 µg/L
• atrazine 3 µg/L

51
Secondary Standards (RMCL)

• cause taste, odor, stains, etc.
• examples
• iron, manganese, pH
• EPA Drinking Water Hotline
• 1-800-426-4791 or http//www.epa.gov/safewater

52
Water Testing

• 131 pesticides detected in groundwater of 4 states

53
Water Testing

• Every Year
• coliform bacteria
• Every 3 Years
• pH
• total dissolved solids
• local pollutant?

54
Local Testing of Well Water

• H H Water Controls Charmichaels, PA
• test for coliform bacteria, e. coli, inorganics,
  arsenic, lead, copper, mercury and others
• Each test has an added cost base test is 22.00
  all other items have an individual charge.
  
• 724-966-2278

55
Local State Water Well Test Site

• Department of Environmental Protection
  New Salem
  Road
  Uniontown, PA
• test only for coli form bacteria
• cost 10.00
• 724-439-7430

56
Local Regional Testing Laboratory

• Sky View Laboratory, Inc. PO Box 273
  Jennerstown, PA 15547
  
• Agriculture
• Drinking Water
• 1-814-629-5441

57
Regionally Located International Environmental
Testing Laboratory

• Free-Col Laboratories
  Meadville, PA
• Wastewater (landfills, industry, etc.)
• Pesticides
• Drinking Water
• 1-800-836-4130

58
National Testing Lab

• National Testing Laboratories
• 1-800-458-3330
• for cases where comprehensive water test is
  needed due to multiple contaminants
• Landfills
• Industry
• Pesticides
• 70 parameters (coliform, metals, inorganics,
  physical, THMs, VOCs) for 120
• Add pesticides, herbicides, PCBs for an
  additional 30
• http//www.watercheck.com

59
Penn States Web Site

• www.extensionwater.psu.edu

60
Credits

• Pesticides and Groundwater NRAES Publication 34
• Cornell Cooperative Extension
• University of California Cooperative Extension
• Penn State Cooperative Extension
• School of Forest Resources

61

• Program originally produced
• by Jim Clark Don Fretts PSU Cooperative
  Extension Educators
• Revised through a grant with the
• Pennsylvania State University Pesticide Education
  Department,
• and Christina Becker
• for the Southwest Pesticide Education Committee
• March, 2006