Pesticides

and

Water Quality

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.

Precipitation

Transpiration

Evaporation

The Water Cycle

Unsaturated RockUnsaturated Rock

CapillaryCapillaryWaterWater

WaterWater TableTable

SaturatedSaturatedWaterWater

Saturated RockSaturated Rock(Aquifer)(Aquifer)

What is Groundwater?

SoilSoil

How Long Does it Take Rain Waterto Get to the Stream?

DaysDays

WeeksWeeks

MonthsMonthsYearsYears

On average – it takes about 6 to 12 months on a forested watershed.

The Watershed

A completely cutexperimental

watershedin Central PA

Groundwater Moves!

Direction of ground water flow

WHPAhome and

septic system

stream

barn and feed lot

Distribution and increased awareness of extension publications and resources?

Consequences of GW Contamination

Often impossible to clean, lasts for years

GW Contamination Factors:

Pesticide properties

Soil properties

Site conditions

Applicator practices

Pesticide Properties

Adsorptivity

Degradation Rate

Solubility

Volatility

Persistence

Pesticide Properties

Adsorption

Attached to soil or organic matter.

Groundwater Contamination Factors – Pesticide Properties

Pesticide Properties

Absorption

Uptake into plants or animals

Groundwater Contamination Factors – Pesticide Properties

Pesticide Properties

Degradation

Broken down into other chemicals like Carbon Dioxide and water.

Microbial degradation

Chemical degradation

Groundwater Contamination Factors – Pesticide Properties

Pesticide Properties

Photodegradation

Broken down by sun

Groundwater Contamination Factors – Pesticide Properties

Pesticide Properties

Solubility

Groundwater Contamination Factors – Pesticide Properties

Pesticide Properties

Volitization

Conversion to gas

Granular, flowable, and wettable powders – less susceptible to volatilization!

Groundwater Contamination Factors – Pesticide Properties

Pesticide Properties

Persistance

Some

pesticides

remain

in the ground

longer than others

Groundwater Contamination Factors – Pesticide Properties

Soil Properties

Soil Texture

Soil Structure

Soil Organic Matter Content

Soil Permeability

Groundwater Contamination Factors – Soil Properties

Soil Properties

Texture

Groundwater Contamination Factors – Soil Properties

Soil Properties

Structure

Groundwater Contamination Factors – Soil Properties

Soil Properties

Organic Matter

Groundwater Contamination Factors – Soil Properties

Soil Properties

Permeability

Groundwater Contamination Factors – Soil Properties

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

Site Conditions

Depth to Groundwater

Depth to groundwater is major factor!

Groundwater Contamination Factors – Site Conditions

Filtering

Soil Properties

Texture & Organic Matter

Application Events

Solubility

Site Conditions

Geological Conditions

Name Text Bedrock

ft.

Perm-

In/hr

Cap/in soil

Gilpin Silt Loam 2-3 .6-2 .14-.18

Guernsey Channery L 3-7 .6-2 .14-.18

Westm’d Channery L 3.5-5 2-6.3 .16-.2

Wharton Silty Clay 4-6 .6- 2 .6 - 2

Local Soil Properties

Groundwater Contamination Factors – Site Conditions

Site Conditions

Geology of the Soil

Groundwater Contamination Factors – Site Conditions

Site Conditions

Climate

Groundwater Contamination Factors – Site Conditions

Site Conditions

Climate and Irrigation Practices

Annual Rainfall

Groundwater Contamination Factors – Site Conditions

0

1

2

3

4

5

6

7

8

9

Jan Mar May Jul Sep Nov

Month

Inch

es o

f W

ater

Monthly Precipitation and Evapotranspiration in PAMonthly Precipitation and Evapotranspiration in PA

EvapotranspirationEvapotranspiration

PrecipitationPrecipitation

Moisture SurplusMoisture Surplus

MoistureMoistureDeficitDeficit

Groundwater Groundwater RechargeRecharge

Site Conditions

Runoff

Carried by surface water

Groundwater Contamination Factors – Site Conditions

Factors Scouting

Erodibility

Rain Amount

Cover

Site Conditions

Reducing Runoff

Groundwater Contamination Factors – Site Conditions

Pesticide Incorporation

Contour farming

Borders of untreated

vegetation

Applicator Management Practices

Use IPM to reduce pesticide use Pesticide Handling

Mixing Application Storage Disposal

Applicator Management Practices

IPM

Goal – Reduce Pesticide Use to Minimum Levels

Groundwater Contamination Factors – Applicator Management Practices

Scouting

Timing of Application

Beneficial’s

Res. Var.

GMO’s

Applicator Management Practices

Pesticide Handling

Mixing

Groundwater Contamination Factors – Applicator Management Practices

Follow label instruction

Avoid or Contain Spills

Complications of Improper

Handling

Applicator Management Practices

Pesticide Handling

Application

Groundwater Contamination Factors – Applicator Management Practices

Equipment checked

and maintained

Chemigation

Irrigation

Applicator Management Practices

Pesticide Handling

StorageStorage

Groundwater Contamination Factors – Applicator Management Practices

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

Applicator Management Practices

Pesticide Handling

Follow Label Recommendations Triple Rinse Containers Dikes Chemsweep

Groundwater Contamination Factors – Applicator Management Practices

Disposal

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)

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

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

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

Health Effects of Groundwater Contamination

Factors

Chemical Toxicity

Duration of Exposure

Dose

Dose-Response Relationship

Risk of adverse health effects increases with level of exposure.

Threshold?

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

Units of MeasureUnits of Measure

mg/L = ppm mg/L = ppm 1 drop in 116 soda cans1 drop in 116 soda cans

µg/L = ppb µg/L = ppb 1 drop in 116,000 soda cans1 drop in 116,000 soda cans

other special unitsother special units

Health Effects of Groundwater ContaminationHealth Effects of Groundwater Contamination AgricultureAgriculture

nitratesnitratespesticides pesticides coliform bacteriacoliform bacteria

Maintenance, Testing, Treatment and Protection are all voluntary!!!

Health Effects of Groundwater ContaminationHealth Effects of Groundwater Contamination Private Water SuppliesPrivate Water Supplies

Proper Well Construction

sloping ground

“sanitary” well cap

grout sealcasing to bedrock

•Divert surface water away from wellhead•Prevent insects and animals from getting under the well cap

bedrock

EPA Drinking Water StandardsEPA Drinking Water Standards

Gives the Gives the

““acceptable level” of pollutant acceptable level” of pollutant

in drinking waterin drinking water

Primary Standards (MCL)Primary Standards (MCL) (maximum contaminant level)(maximum contaminant level)

health based health based enforced (public systems)enforced (public systems)examples:examples:

coliform bacteria: <1/100 mlcoliform bacteria: <1/100 ml nitrate: 45 mg/Lnitrate: 45 mg/L PCE: 5 µg/LPCE: 5 µg/L atrazine: 3 µg/Latrazine: 3 µg/L

cause taste, odor, stains, etc. cause taste, odor, stains, etc.

examples:examples:

iron, manganese, pHiron, manganese, pH

EPA Drinking Water HotlineEPA Drinking Water Hotline

1-800-426-4791 or 1-800-426-4791 or

http://www.epa.gov/safewater

Secondary Standards Secondary Standards (RMCL)(RMCL)

Water Testing

131 pesticides detected in groundwater of 4 states

Water TestingWater Testing

Every YearEvery Year

• coliform bacteriacoliform bacteria

Every 3 YearsEvery 3 Years• pHpH• total dissolved solidstotal dissolved solids• local pollutant?local pollutant?

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

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

Sky View Laboratory, Inc. PO Box 273 Jennerstown, PA 15547

Agriculture

Drinking Water1-814-629-5441

Local Regional Testing Laboratory

Free-Col Laboratories Meadville, PA

Wastewater (landfills, industry, etc.)

Pesticides

Drinking Water1-800-836-4130

Regionally Located International Environmental Testing Laboratory

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, THM’s, VOC’s) for $120 Add pesticides, herbicides, PCB’s for an additional

$30 http://www.watercheck.com

Penn State’s Web Site

www.extensionwater.psu.edu

Credits

Pesticides and Groundwater NRAES Publication 34

Cornell Cooperative Extension University of California Cooperative

Extension Penn State Cooperative Extension

School of Forest Resources

Program originally produced by Jim Clark & Don Fretts – PSU Cooperative Extension Educators

Revised through a grant with thePennsylvania State University Pesticide Education Department,

and Christina Beckerfor the Southwest Pesticide Education Committee

March, 2006