Contaminants in sediments endanger bottom-dwelling organisms like crayfish, and are threats to birds and other creatures that eat these organisms. OGI s results are designed to provide the key information that has not yet been obtained. BES wants to gain the greatest improvement in environmental quality for the least amount of money. The details about contaminant distribution provided by OGI will allow Parametrix to fine-tune its risk assessments for the city. This detailed risk analysis will help BES create a final cleanup plan that attacks the worst problems first, and avoid wasting resources on areas that present minimal risk to humans or the environment.
Colloids are particles so small that they often appear to be dissolved in the water.
Contaminants can adhere to colloids and thereby also seem dissolved in the water. Truly dissolved contaminants present a high risk to organisms, but colloid-bound contaminants may present little or no danger. Thus, BES and its contractors must be able to distinguish between contaminants adhered to these fine particles and the more dangerous fraction of contaminants in true solution. Existing measurements of contaminants in sediment pore water are an important part of establishing the risk posed by these contaminants, and thus affect the direction of the cleanup. The OGI results will help BES and Parametrix avoid potentially costly overestimates of risk by making this critical distinction possible.