Legacy Chlordane in Soils from Housing Areas Treated with Organochlorine Pesticides

Chlordane was used for termite prevention in Air Force housing areas, where it was sprayed heavily on the ground around building exteriors. Base closure regulations require the Air Force to assess residual chlordane in the soil. The USACE-ERDC team examined two soil types containing chlordane residuals a Silty Sand and a Sand soil type from housing areas at McGuire AFB, NJ, and Davis-Monthan AFB, AZ, respectively. Using these two soils, chlordane leachability was evaluated the potential for chemical or biological degradation of the chlordane was evaluated the potential toxicity of the chlordane was assessed using plant and earthworm bioassays. Leachability was tested using four different procedures. The potential for chemical remediation was evaluated by alkaline hydrolysis and persulfate oxidation. The potential of biodegradation was evaluated by composting with spent mushroom waste. The soil toxicity and uptake of chlordane into plants and earthworms was also assessed. The results of these investigations indicated that aged chlordane in the soil was not likely to desorb and migrate under either landfill or physiological conditions. Chlordane in solution was susceptible to photodegradation and alkaline hydrolysis, chlordane in soil was not. Chlordane in soil was also not susceptible to persulfate oxidation. Composting did show promise as a long-term ex situ remediation strategy. Biouptake results indicated that chlordane did not adversely affect seed germination, root length, or shoot length. The plants did uptake chlordane from the soil and translocate it to the shoots. The presence of chlordane did not affect earthworm mortality, but did affect weight loss and reproductive success.