Final answer:
A well should be protected from back-siphoning of pesticides, not located near a pesticide mixing and loading site or storage facility, and properly abandoned when no longer useful to prevent contamination of the water supply.
Step-by-step explanation:
A well should be protected from back-siphoning of pesticides to prevent contamination of the water supply. The best way to achieve this is by installing a backflow preventer, which is a device that stops the reverse flow of water. This prevents any pesticides or other contaminants from entering the well.
Locating a well within 100 feet of the pesticide mixing and loading site is not recommended due to the risk of contamination. Pesticides can easily be spilled or sprayed onto the ground during the mixing and loading process, and being in close proximity to the well increases the chances of these chemicals seeping into the water supply.
The well should not be located near the pesticide storage facility because the risk of contamination is high. Pesticide storage facilities may have leaks or spills, and if the well is nearby, there is a higher chance of the groundwater being contaminated.
Cutting off the well below the soil surface and abandoning it when no longer useful is not the best practice. Proper abandonment procedures should be followed to ensure that the well is sealed correctly and does not pose a risk of contamination in the future.