Waterway sediments represent one of the most complicated and expensive liabilities for many industrial and petroleum clients, with costs for many legacy sites in the multi-million dollar range. Issues for many of these sites focus primarily on the presence of petroleum chemicals, particularly their potential effects on fish and other natural aquatic resources. However, sediment is a complex environmental matrix composed of a diverse mixture of materials than can greatly affect the mobility and behavior of petroleum chemicals, especially with regards to the potential for adverse effects that drive site decisions and regulatory concerns. Traditional measurement techniques for understanding these chemicals in sediment are widely known to over-predict chemical risks, leading to overly-protective sediment management actions that can waste hundreds of thousands to millions of dollars per site.
Recently, a new technique – Passive Sampling – has become available to provide a more robust assessment of sediment contamination. Passive sampling involves exposure of an inert, sorptive solid device into sediment, followed by the analysis of the chemicals absorbed by the sampler. In this way, passive sampling mimics chemical uptake by fish and other aquatic life, the key focus of the most sensitive environmental regulations. The resulting passive data offer a more realistic view of chemical risks, avoiding overly-stringent and expensive sediment management approaches. Because the technology has now fully transitioned from pure research to routine application (with state and federal regulatory support), costs to apply passive sampling represent only a modest 20-30% additional investment for typical site investigation budgets. Due to the additional confidence in site assessments that can be provided by passive sampling data, many contaminated sites can realize sediment management cost savings approaching several thousand to several millions of dollars.
This presentation will provide an overview of passive sampling science and strategic application to contaminated sediment assessment and management, drawing from the speaker's 20-year experience in passive sampling and recent development of commercial passive sampling services in the environmental consulting industry. A key focus of the presentation will be the state and federal regulatory acceptance of the approach, including several examples and case studies on the use of passive sampling to aid decision-making at contaminated sites.