B. J. LANDFILL
NORCROSS, GWINNETT COUNTY, GEORGIA
Since there has been no significant off-site migration of contamination recorded at this landfill, the primary concern for exposure to toxic compounds exists on site. With the exception of one private well, the entire area around the site is supplied by a public drinking water system. The single private drinking water well has been tested and has not shown levels of contamination above MCLs that are attributable to the solid waste unit. Therefore, only on-site exposure pathways are considered (TABLE 1). Due to the presence of elevated levels of contaminants in landfill gas, landfill leachate, and on-site surface water, these pathways must be examined for the potential that on-site workers, visitors, and trespassers were exposed. Due to containment and treatment activities currently performed on site, the only potential exposure pathways that may exist are those that have occurred in the past.
There have been several sampling efforts of landfill gas at this landfill, but the results have been very inconsistent. As mentioned before, VOCs have been detected in the landfill gas. Some of these sampling results indicated the presence of high levels of several VOCs, including 1,1 DCE, cis-1,2 DCE, ethylbenzene, methylene chloride, PCE, toluene, TCE, vinyl chloride, and xylenes. Exposure to any of these contaminants was very unlikely, and if exposure had occurred, it would have been intermittent.
Concerns were raised by the consultant for GWSI (2) over the potential that landfill leachate has been released to the surface before the leachate recovery system was installed. In an interview with several of the on-site workers, there was no recollection of such events occurring (6). A number of VOCs have been found in the landfill leachate as well as several metals. Exposure to any of these contaminants was very unlikely, and if exposure had occurred, it would have been intermittent.
Although significant levels of contamination exist in the sedimentation pond on site, the likelihood that anyone would come into contact with this media is extremely unlikely. Also, due to the transient nature of employment at this site in the past and the variation of activities which are performed on-site, it is unlikely that any exposure to surface water would be for prolonged periods of time.