Site remediation after waste disposal

In implementing the risk-based waste classification system developed in this Report, the selection of exposure scenarios appropriate to waste disposal is an important technical issue that must be addressed. NCRP believes that scenarios for inadvertent intrusion into near-surface disposal facilities are appropriate in classifying waste for purposes of disposal and, further, that scenarios involving permanent occupancy of disposal sites after loss of institutional control would be appropriate (see Section 6.1.3) such scenarios are commonly used in regulating near-surface disposal of low-level radioactive waste and in risk assessments at hazardous waste sites subject to remediation under CERCLA. 

Every year billions are spent to capture, contain, and remedy solid wastes after their generation, and costs for hazardous waste treatment and disposal have multiplied during the past few years because of the limited availability of treatment and disposal sites and facilities. 

A New Bedford Harbor Sawyer Street site in Massachusetts has been designated as a superfund site due to PCB contamination of river sediments. Commodore was one of three companies chosen to conduct demonstration studies on-site under contract to Foster Wheeler Environmental Company. The river sediment was first washed with diisopropylamine by the Ionics RCC B.E.S.T process [35], producing an oil concentrate. The PCB level in the B.E.S.T concentrate was approximately 32,800 ppm. Dioxins/furans (TEFs) were also present at 47 ppm. This concentrate was reacted with SET in the SoLV process to destroy the PCBs and dioxins (Table 4). After treatment, the PCB level was 1.3 ppm, well below regulatory requirements for disposal in nonhazardous waste landfills. Dioxins were also readily remediated. This study also illustrates that the SoLV process can remove metals from substrates. The concentrate received was found to have lead, arsenic, and selenium in high parts-per-billion levels. After treatment with the SoLV process, the levels were below detection limits. The metals were... 

Non-stockpile chemical material (e.g., wastes from past CW agent disposal efforts, unserviceable munitions, contaminated containers, and found rounds that have been recently located after having been historically buried) are also undergoing disposal. Furthermore, any soil or groundwater that may be contaminated by potentially toxic agent re.sidues at the sites where non-stockpile material has been found are remediated and subjected to the protocoLs of a formal cleanup program (Opresko ct al 1998, 2001 Bakshi etai, 2000). 

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