Sediment Site Characterization for Hydrophobic Organic Contaminants: Passive Sampling Techniques and Novel Sensors



Aquatic sediments represent one of the most complicated and expensive liabilities for many contaminated sites, with costs for many legacy sites in the multi-million dollar range. Issues for many of these sites focus primarily on the presence of hydrophobic organic compounds such as PCBs and petroleum chemicals in sediment. However, sediment is a complex environmental matrix composed of a diverse mixture of materials than can greatly affect the mobility and behavior of 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. As this technology has now fully transitioned from pure research to routine applications (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-plus years of 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. In addition, the presentation will cover a new, portable, field-deployable antibody-based biosensor technique that can compliment passive sampling measurements for petroleum compounds, providing data within a matter of minutes using a small volume of sediment porewater.

The Presenters:

Jason Conder
Dr. Jason Conder is a Principal at Geosyntec Consultants in Huntington Beach, California. He has more than 15 years of consulting experience in environmental toxicology, ecological and human health risk assessment, bioaccumulation and bioavailability of environmental contaminants, environmental chemistry, environmental monitoring technology, and statistics. A key part of his research and consulting focus over the past 23 years has been on the application of passive sampling techniques to evaluate the fate and availability of metals and organics in soil, sediment, and water. In addition to conducting basic research on passive sampling approaches and techniques, Jason has applied passive samplers for a wide variety of decision-making uses at contaminated sites, shedding light on key issues of environmental risk, chemical fate, and the success of remediation applications. In 2015, Jason helped foster the development of a successful commercial passive sampling service offered by SiREM, and he continues to be a key partner in further developing and refining their efforts. Jason has published more than 20 peer-reviewed articles in Environmental Toxicology and Chemistry, presented technical work at numerous international scientific conferences, and has served on and co-chaired several technical workshops.

Brent Pautler
Brent Pautler is the Customer Service Coordinator at SiREM and an environmental analytical chemist with advanced technical experience in passive sampling, spectroscopy, chromatography, mass spectrometry and chemistry informatics. Throughout his career he has been dedicated to working with scientists, engineers and consultants, applying his chemistry and information technology expertise to help them solve unique problems both in the laboratory and the field. He is the lead contact at SiREM for passive sampling products and services including Waterloo Membrane Sampler (WMS)™ for vapor intrusion and soil gas, SP3™ & SPeepers™ for sediment pore water and surface water while supporting SiREM’s bioaugmentation culture clients.