NATURAL STABILIZATION OF STORED INDUSTRIAL SLUDGES

Current regulations governing the closure of a waste impoundment require either complete removal of the waste from the impoundment or appropriate remediation of the material in the impoundment followed by application of permitted secure cover to prevent exposure and off-site migration of residual chemicals. With the emergence of RBCA and the concept of EAEs, regulators and industries have begun to explore innovative approaches that may be utilized in a RBCA effort and that will be equally protective as the more traditional impoundment closure approaches. The comparison of the availability of PAH, as estimated by ROR, TCLP, SPLP, and Microtox toxicity tests, between the surface and deep composite samples indicated that the availability of PAH in surface impoundment layers was much lower than the availability of PAH in the deeper impoundment layers. The growth of the vegetation on the impoundment surface was the likely cause of the differences.