Laserfiche WebLink
i <br /> t <br /> 1 <br /> � I <br /> contamination as the dissolved plume usually imp&cts <br /> water suFply wells or groundwater dischargc { <br /> ri points <br /> (streams, s <br /> P ngs) . The dissolved phase typically <br /> increases with time as the free product diid adsorbed _ <br /> Phases continues to leach contaminants into the ground- <br /> water system. --- <br /> ° The vapor Fhas.c of contamination results from the ' ' } <br /> volatile portions of the relecsed <br /> Product solution and' concentrating in the subsurface.coming of <br /> magnitude of the vapor plume depends on the volume <br /> of loss, type Of contaminants, and the site geology. <br /> Impact= from the vapor Phase depend on the <br /> p pressure '.1 <br /> differential between the subsurface and the below t. <br /> ground structures ! r <br /> i.e basements, foundations, <br /> underground utilities) . This means that vapors tend <br /> to migrate from high pressure areas to low pressure f <br /> areas. Depending on the time of year and constuction <br /> of below around or at grace . `uctures, the subsurface <br /> may be high pressure zone+ and basements or foundation <br /> areas may become the lov• pressure zones. This phase <br /> needs to` be addressed in every investigation as thq <br /> exposure to <br /> the PkII)lic Mny be the greatest as vapors <br /> tend to migrate further and faster than the other three <br /> Phases of contamination. <br /> t <br /> Y <br /> With this cognizance, when approaching an aquifer contamina- <br /> tion evaluation and clean up, it J.. necessary to both be aware of <br /> the various phases an knowledgeablra <br /> crritribate. in the amount of impact they <br /> See Figure 5 for ch�,matic of four phases of <br /> "�n1•nminiititn, <br /> i <br />