Evaluation of the Adequacy of Hazardous Chemical Site Remediation by Landfilling

Ultimately, hundreds of billions of dollars of public and private funds will be spent in the US in hazardous chemical site (Superfund and closed RCRA facilities) investigation and remediation. A critical review of the adequacy of remediation of many of these sites that are “closed” in accord with RCRA and/or CERCLA requirements as being interpreted by regulatory agency staff/boards and principle responsible parties (PRPs) and their consultants shows that the residues of hazardous and deleterious chemicals left at the site after current required remediation represent significant long-term threats to public health, groundwater quality, the environment, and those that live on or use properties within the sphere of influence of the “remediated” site. A major fundamental problem with current hazardous chemical site investigation/remediation is that the long-term threats of residual chemical constituents left at the site after remediation is not adequately or reliably evaluated and managed. This situation will mean that many closed hazardous chemical sites will have to be re-remediated at some time in the future under conditions where there is inadequate funding available to adequately investigate and remediate the site. This chapter reviews some of the longer-term issues that need to be evaluated as part of determining the adequacy of hazardous chemical site investigation and remediation relative to evaluating the long-term threats that remediated site residual chemical constituents represent a threat to public health and the environment. The deficiencies in the use of on-site or off-site landfills that meet current interpretation of RCRA Subtitle C and D requirements for site remediation is the major area addressed in this chapter. Today’s RCRA Subtitle C and D landfills, with a single or double composite liner and vertical groundwater monitoring wells spaced hundreds to a thousand or more feet apart at the point of compliance for groundwater monitoring, at best only postpone when off-site groundwater pollution will occur. The composite liner and cover systems used in RCRA Subtitle C and D landfills have a limited finite period of time compared to the time that the waste residues will be a threat during which the containment system components can be expected to function effectively to prevent groundwater pollution by landfill waste residues. The groundwater monitoring systems allowed at today’s Subtitle C and D landfills have a low probability of detecting groundwater pollution by landfill leachate before off-site pollution occurs. Basically, today’s Subtitle C and D landfills represent a fundamentally flawed approach for managing hazardous and/or deleterious waste chemicals that only postpones when there will be need for re-remediation of the hazardous chemical site.