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r Geosyntec Consultants <br /> S . LEACHATE FROM C&D DEBRIS <br /> Presently, the SWDD disposes C &D debris in unlined landfills . The leachate (created from the <br /> interaction of C&D waste with rainfall or groundwater) may contain trace amounts of <br /> hazardous chemicals . (This leachate is presently not collected and tested due to the lack of <br /> liner and leachate collection system underneath the C&D disposal facility cells at the IRCL <br /> facility.) Sources of such chemicals include solvents and adhesives, as well as, the primary <br /> construction material themselves . While the chemicals leaching from materials such as wood, <br /> drywall and concrete are not typically toxic, they can contribute to an overall degradation of <br /> groundwater quality. Simulated leachate from C&D debris containing drywalls was found to <br /> exceed the secondary maximum contaminant levels (MCLS) for drinking water for Total <br /> Dissolved Solids (TDS ) and sulfate [Townsend et al, 2000] . Also, sulfides were formed from <br /> the conversion of sulfate by sulfate-reducing bacteria under the unsaturated and anaerobic <br /> r <br /> conditions. <br /> In another study of the quality of C&D debris leachate, which included laboratory and field <br /> r tests, leachate generated from C&D debris was found to be turbid and black in color and <br /> contained a strong hydrogen sulfide odor [Townsend, 2002] . The source of sulfate was <br /> believed to be the dissolution of gypsum drywall (CaSO4 2H2O) . Also, aluminum, iron, and <br /> manganese were detected in all of the leachate samples. Arsenic, chromium, copper, and lead <br /> were also routinely detected. The most likely source of arsenic, chromium , and copper was <br /> chromated copper arsenate (CCA)-treated wood, which used to be a common construction <br /> material in Florida [Hinkley, 2003 ] . As part of the proposed rule changes, proper CCA-treated <br /> management and practices, that includes sorting and removal from the waste loads, will be <br /> r. required at all unlined C&D disposal facilities in Florida. Trace organic compounds may be <br /> found in paint thinners, stains, motor oils, plastics and paints, which are uncommon, but <br /> occasionally observed in the construction waste stream . <br /> r <br /> FL0996-03UL70184_08- 10-2007.doc.doc 5- 1 2007-08-10 <br /> r <br />