1. Where is ground water found?

a. In underground lakes and rivers.
b. In aquifers (zones beneath the earth's surface).
c. In water under houses, farm buildings, etc.

2. What are two examples of non-point source contamination?

a. Plant nutrients leached into the ground water.
b. Nitrates from animal wastes tilled into a field at excessive rates leaching to shallow ground water.
c. Leaking underground petroleum tanks.
d. Crop chemicals washing from field into a cracked well casing.

3. What are two examples of point source contamination?

a. Improper disposal of solid and hazardous wastes.
b. Crop chemicals washing from fields into an old well casing.
c. Sediment eroding from an irrigated field.
d. Plant nutrients leached into ground water.

4. How can pesticides enter the ground water?

a. Leaching through the soil.
b. Surface runoff.
c. Spills into abandoned wells.
d. Back siphoning into wells.
e. Substandard well construction.
f. Improper rinsate and container disposal.

5. Are pesticides more or less likely to move into the ground water if they have strong "soil adsorption" characteristics?
    a. More             b. Less

6. If pesticides are comprised of "persistent" materials, are they more or less likely to move into ground water?
    a. More             b. Less

7. Which soil textures are more likely to have pesticides leach through them?
    a. Coarse soils.
    b. Light-textured soils.
    c. Fine soils.
    d. Heavy-textured clay soils.

8. Which soil characteristic enables water to move through soil?
    a. Texture.
    b. Permeability.
    c. Organic matter.

9. Which soil characteristic determines how much water can be held before movement occurs?
    a. Texture.
    b. Permeability.
    c. Organic matter.
    d. None of the above.

10. What can growers do to reduce potential ground water contamination from pesticides?
    a. Handle chemicals safely.
    b. Mix and calibrate accurately.
    c. Protect wellheads.
    d. Prevent back siphoning.
    e. Avoid runovers.
    f. Properly rinse used containers.
    g. Properly dispose of containers.

ANSWERS

1. b
2. a and b.
3. a and b.

4. All answers are correct. And all are preventable with safe handling and disposal procedures.

5. b. Some chemicals become tightly attached (adsorbed) to soil particles in the upper soil layers and don't travel or migrate. Some are not so tightly adsorbed and, thus, are more likely to migrate.

6. a. Some chemicals break down quickly; "persistent" materials take a longer time to break down.The longer it takes for a chemical to break down, the longer it will be present in the environment...perhaps causing a problem if it reaches ground water.

7. a and b. Leaching is generally more rapid and deeper in coarse or light-textured soils than in fine or heavy-textured clay soils.

8. b. Where soils have low permeability, water tends to collect, causing runoff. The more permeable soils must be carefully managed to prevent chemicals from reaching ground water.

9. c. High organic matter increases water retention and tends to hold pesticides in place.

10. a through g are correct. By following these guidelines, ag chemical applicators can dramatically reduce the chance of any pesticides reaching our ground water supply.