Landfill Groundwater Quality Remediation Program, 1990 Environmental Conference Proceedings

This landfill for pulp and paper mill wastes has been operated by Boise Cascade, Mexico, Maine since 1976. The landfill was constructed with a sludge liner for leachate containment, and a bentonite clay-lined pond for leachate storage. Beginning in the mid 1980’s. monitoring wells located at the downgradient end of the valley began to show increasing levels of conductivity. In response to this increase, an hydrogeologic investigation was conducted to assess the hydrogeologic characteristics of the site, evaluate the effectiveness of the landfill containment systems, and recommend measures to remediate the impacted groundwater. The hydrogeologic investigation identified several potential sources of the contamination and recommended improvements to the landfill design, including replacing the existing leachate pond with a flexible membrane-lined pond, and improving the leachate transport system. The remedial measures were instituted in late 1986. Improvements to groundwater quality have been observed at the site since the remedial activities were undertaken in 1986.