Several factors can affect the movement of a herbicide through the soil profile. These include soil texture, organic matter, location of water table, and herbicide characteristics such as solubility, persistence (half-life) and the herbicides ability to adsorb or bind to soil. Most herbicides have the potential to move in soil or water, although for acetochlor the potential is small due to rapid degradation by soil micro-organisms. However, the potential has been virtually eliminated by the following additional restrictions included in all acetochlor product labels.
Acetochlor should not be mixed within 50 ft of any wells, including abandoned wells and drainage wells, sink holes, intermittent streams and rivers, and natural impounded lakes and reservoirs. This does not apply to properly capped wells or properly diked mixing/loading areas.
On the following soil types, do not apply acetochlor within 50 feet of any well where the depth to ground water is 30 feet or less:
- sands with less than 3 percent organic matter;
- loamy sands with less than 2 percent organic matter; or
- sandy loams with less than 1 percent organic matter.