May 13, 2012 – Termiticides And Aquatic Sites
QUESTION:
What distance is safe from a body of water to foam a tree with an active formosan termite infestation?
ANSWER:
When treating with any pesticide where any aquatic site is nearby you are bound by the Label instructions, if there are any, and if there are no specific label statements then you need to go with good reasoning and observation. In the case of a termite treatment such as you mention I looked only at one termiticide label, but it serves as a good example. The Dragnet SFR label states that you may "not apply by ground equipment within 25 feet of lakes, reservoirs, rivers, permanent streams, marshes or natural ponds, estuaries, and commercial fish farm ponds". This, therefore, becomes the minimum distance you must stay from any kind of aquatic site.
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What distance is safe from a body of water to foam a tree with an active formosan termite infestation?
ANSWER:
When treating with any pesticide where any aquatic site is nearby you are bound by the Label instructions, if there are any, and if there are no specific label statements then you need to go with good reasoning and observation. In the case of a termite treatment such as you mention I looked only at one termiticide label, but it serves as a good example. The Dragnet SFR label states that you may "not apply by ground equipment within 25 feet of lakes, reservoirs, rivers, permanent streams, marshes or natural ponds, estuaries, and commercial fish farm ponds". This, therefore, becomes the minimum distance you must stay from any kind of aquatic site.
Other considerations come into play, such as the possible presence of a high water table, a treatment to soil that may be lower than the nearby water site, etc. Since you desperately want to keep any termiticide out of surface as well as ground waters you might consider treating in the manner the label states when treating with a well or cistern under a structure, and that is with the treated backfill method. You remove soil, place it on a plastic tarp, treat the soil with the appropriate volume of the termiticide and ensure it is evenly mixed in the soil, and once it is absorbed properly in that soil you replace the treated soil into the trench it came from. Once termiticides are absorbed into soil particles, and particularly when they are dry, they bind (adsorb) tightly to the soil and will not move. Our termiticides in general have a very low water solubility, meaning they do not dissolve in water at any appreciable level and therefore will not be carried through the soil with subsequent rainfall.
If you are foaming directly into a tree, where hollow areas exist, then it would be advisable to use a very "dry" foam that will prevent it from running. This will allow the foam to fill the cavity and then dissipate as the bubbles break, leaving the active ingredient only on the surfaces you treated instead of flowing downhill and into the soil below. However, you still would need to adhere to that 25 feet distance from nearby aquatic sites as stated on the Dragnet label.
Other considerations to look for when treating outdoors would be soil type and degree of the slope. If you have a steep slope it would encourage runoff rather quickly. If you have a very porous soil, such as a sandy texture, this could allow liquid applications to move much deeper, since there is less actual clay or organic matter for the active ingredient to adhere to. If you have a soil that is already saturated, perhaps by recent heavy rains, then you would want to avoid getting termiticide onto it as the liquid you apply may not soak in and could more easily run off the area.
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