Termiticide Leachate from Building Foundation Drains

Abstract

This study determined whether termiticides (insecticides that are formulated and applied for termite control), applied according to label directions to the soil surrounding basement walls, can leach into foundation drainpipes. A licensed applicator injected silt loam and loamy sand soils adjacent to full-scale basement walls with technical chlordane and chlorpyrifos, according to label directions, using standard rod-injection equipment and procedures. During the rod injection, the termiticide flowed directly into foundation drainpipes at a rate of 300 mg technical chlordane and 180 mg chlorpyrifos per meter length of drain pipe. More termiticide was injected into the soil at deeper depths than at shallower depths. Over an eight-month period, 2 mg technical chlordane and 16 mg chlorpyrifos per m length of drain pipe were leached into the drainage system. It is concluded that, when applied according to label directions, termiticide can leach from foundation drainpipes, especially during injection. Recommendations include modifying equipment and the rodding technique to eliminate direct injection into drainpipes, increasing the number of injection holes to reduce termiticide volume per hole, and modifying injection protocol when shrinkage cracks are present.