REMEDIATION OF DICHLOROMETHANE (DCM)-CONTAMINATED GROUND-WATER

This case history describes the physical and biological treatment of dichloromethane (DCM)-contaminated ground water following the rupture of an underground pipeline which contaminated an estimated 11,000 m3 (14,000 yd3) of soil and ground water in the early fall of 1983. Air stripping DCM from recovered ground water was initiated and provided an estimated 97% reduction in the ground water concentration of DCM. When it became evident that physical treatment alone would no longer be effective in removing residual DCM from the ground water environment, the practice of air stripping DCM from recovered ground water was terminated. Biological treatment was initiated and provided greater than a 500,000-fold reduction in the ground water concentration of DCM. Biological treatment had far exceeded the ability of physical treatment alone to remediate a ground water environment contaminated with a biodegradable contaminant.