February 22, 2018

Geosyntec Staff to Present at Emerging Contaminants Summit in Colorado

Geosyntec staff will make a significant technical contribution to the Emerging Contaminants Summit at the Westin Westminster in Westminster, Colorado on March 6-7, 2018.

This year, Geosyntec is proud to have developed the summit's technical program and to support the summit as a Platinum Sponsor. We are also pleased to share our discounted registration rate with our clients and colleagues. Visit http://www.contaminantssummit.com/ to register and enter discount code GeosynVIP to take advantage of the 25% discount.

The Emerging Contaminants Summit is dedicated to the latest developments in the detection, fate and transport, risk assessment, treatment, and regulation of emerging contaminants. The summit attracts leaders and key stakeholders from academia, government, and regulators, as well as site owners, private consulting agencies and other environmental professionals. The conference's overarching goal is to promote discussion on the mitigation of emerging contaminants across all environmental media including surface water, groundwater, drinking water, wastewater, recycled water, and soils.

Geosyntec Participation

Senior Principal Rula Deeb (California) is one of the Conference Chairs and will give the opening and closing remarks.

Senior Engineer Tasha Kamegai-Karadi (California) will be presiding over the Student Program and will be assisted by Justin Knight (Georgia) and Emily Stockwell (Colorado).

Title: Breakthroughs and Lessons Learned from Treating 1,4-Dioxane in a Chemically Complex Water Stream
Presenter: Senior Principal Brian Petty (California)
Time: 1:55 p.m. to 2:20 p.m.
Date: March 6, 2018
News of 1,4-dioxane detections in drinking water, groundwater, wastewater, and surface water is becoming increasingly more common, yet the list of proven and cost-effective treatment technologies remains relatively short. The need for a larger variety of treatment options is especially pronounced when faced with treating 1,4-dioxane concentrations that are near the regulatory levels (i.e., less than 10 micrograms per liter) being developed in numerous states. Recent bench, pilot, and full-scale treatability studies performed on a chemically complex wastewater in southern California have provided comparative performance data at a range of 1,4-dioxane concentrations for several technologies including advanced oxidation, carbon adsorption, synthetic media adsorption, and biological degradation. The studies have clearly shown that the treatment technologies each have strengths and weaknesses, and those strengths and weaknesses are highly dependent on the overall quality of the liquid matrix.
The presentation will compare the results of the treatability tests and describe the unique lessons learned in treating chemically complex water which poses varying degrees of treatment challenges and interferences to each technology. In recognition of the challenges posed by 1,4-dioxane and the widespread need for polishing treatment technologies, biofilm reactor configurations are being tested at the bench scale. Findings and recommendations regarding biofilm reactor loading rates, media, and enrichment cultures will also be presented.

Title: Field Validation of Low-Level TCP Remediation Approaches
Presenter: Principal Eric Suchomel (California)
Time: 2:20 p.m. to 2:45 p.m.
Date: March 6, 2018
1,2,3-Trichloropropane (TCP) is an emerging groundwater contaminant characterized by high mobility in the subsurface, resistance to natural attenuation and some engineered remedies, and low regulatory levels relative to other volatile organic compounds. Since the mid-2000s, Geosyntec and collaborators have been evaluating remedial technologies TCP, including groundwater extraction and treatment, in situ chemical oxidation (ISCO), in situ chemical reduction (ISCR), and in situ bioremediation (ISB). Of these, ISB and ISCR have been identified as particularly promising technologies for TCP remediation at the low concentrations of regulatory interest, and proof-of-concept testing has been implemented in the past several years at scales ranging from laboratory treatability studies to full-scale field implementation. This presentation includes results from ongoing research and field studies intended to validate ISB and ISCR as technologies for remediation of low levels of TCP in groundwater.

Session: #5
Title: 1,4-Dioxane: Biological Treatment
Chair: Principal Jennifer Nyman (California)
Time: 3:45 p.m. to 5:15 p.m.
Date: March 6, 2018

Session: #6
Title: Emerging Contaminats: U.S. Geological Survey Research Highlights
Chair: Senior Principal Evan Cox (Ontario)
Time: 3:45 p.m. to 5:15 p.m.
Date: March 6, 2018

Title: Prioritizing Data Needs for Assessing the Ecological Risks of PFASs in Habitats Impacted by Aqueous Film-Forming Foam Releases
Presenter: Senior Scientist Jason Conder (California)
Time: 11:15 a.m. to 11:40 a.m.
Date: March 7, 2018
Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) have been widely used in numerous industrial and commercial applications since the 1950s, including aqueous film forming foams (AFFFs) used for fire suppression at airports, firefighting training facilities, and other industrial locations. PFASs such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are now routinely-detected in a wide variety of environmental media impacted by AFFF, and have prompted regulatory focus on exposures and risks. Many AFFF sites host ecological habitat or, due to the offsite transport potential for PFASs (especially for aquatic transport routes), may affect nearby or downgradient habitats. Unfortunately, there is little guidance on developing Conceptual Site Models (CSMs) and investigation plans to evaluate the ecological risks of PFASs at AFFF sites. This presentation will highlight key ecological risk considerations for PFAS at AFFF sites, based on reviews of PFAS fate and toxicology information, as well as ecological exposure modeling of PFAS exposures for wildlife at AFFF sites. Our work indicates that PFOS is likely to be a key PFAS of concern at many sites, particularly for avian wildlife. For example, PFOS comprised approximately 80% of the exposure of perfluoroalkyl acids to avian species at five AFFF sites, likely due to its prevalence in many historical AFFF formulations, ability to bioaccumulate in terrestrial and aquatic food webs, and partitioning to soils and sediments. However, exposures to other PFASs, especially perfluorohexane sulfonate (PFHxS) and perfluorodecane sulfonate (PFDS) may also be important, and suggest that avian toxicity testing should be prioritized for these particular PFASs. Model and review results also highlighted several practical steps for site-specific investigations for supporting ecological risk assessments, including:

  1. Focusing investigations on aquatic systems affected or downgradient of AFFF discharge areas;
  2. Screening measurements of PFASs in key abiotic environmental compartments (soils, sediments, and surface water);
  3. Measurements of PFAS in invertebrates and fish; and
  4. Measurements of organic carbon contents in soils and sediments to aid with modeling fate and availability.

Additional considerations for research needs and site-specific ecological risk management approaches will be presented, with the hopes of optimizing ecological risk-based decision making at AFFF sites.

Title: Chemistry Rules: Developing MNA and Remedial Strategies for Emerging Contaminants
Presenter: Principal Leah MacKinnon (Ontario)
Time: 2:15 p.m. to 2:40 p.m.
Date: March 7, 2018
As new contaminants emerge environmental practitioners must seek efficient characterization and remedial strategies to address them. Each emerging contaminant has unique properties which dictate its behavior in environmental media, breaking the mold in which more familiar contaminants have been characterized and treated. Interpretation of concepts such as plume dynamics, attenuation processes and reactivity can be a new challenge for each new class of constituents. Unique chemical properties can also make emerging contaminants resistant to many common in situ and ex situ remedial technologies. This presentation will explore the importance of understanding basic chemical behavior in the development of monitored natural attenuation and remedial strategies, based on a case study.

Practitioner Workshop: #3
Title: Lessons Learned from PFAS Site Investigations
Panelist: Senior Principal Bob Anderson (Washington)
Time: 4:00 p.m. to 5:00 p.m.
Date: March 7, 2018

Poster Presentation
Title: Risk Based Concentrations for Avian Receptors at Aqueous Film Forming Foam (AFFF) Impacted Sites
Presenter: Scientist Emily Larson (Colorado)
Information on the adverse effects of perfluorinated and polyfluorinated alkyl substances (PFAS) in animals is primarily limited to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). While detectable levels of PFOS and PFOA in environmental media are known to be present at many sites as a result of Aqueous Film Forming Foam (AFFF) releases, less is known about other prominent PFAS chemicals. Since birds may have relatively high exposure potential due to consumption of fish, invertebrates, and sediment in aquatic habitats affected by AFFF releases, avian exposures were evaluated for seven PFAS chemicals (PFOS, PFOA, perfluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluorodecane sulfonate (PFDS), perfluorohexanoic acid (PFHxA), and perfluorohexane sulfonate (PFHxS)) using measurements from four AFFF sites. Exposure modeling was conducted for four avian receptors representing various avian feeding guilds including: lesser scaup (Aythya affinis), spotted sandpiper (Actitis macularia), Great blue heron (Ardea herodias), and osprey (Pandion haliaetus). On average, 70% of PFAS exposures were from PFOS for all receptors at almost all sites (with the exception of Site A). For the spotted sandpiper and the lesser scaup, PFHxS comprised over 10% of the total daily intake (TDI). The sediment pathway was the dominant exposure route, however the surface water route greatly contributed to the great blue heron and osprey PFAS TDI (45% and 59% respectively). Furthermore, Risk Based Concentrations (RBCs) were calculated for PFAS chemicals and avian receptors to determine acceptable concentrations in aquatic media. These results suggest the need for ecological modeling at sites potentially affected by AFFF releases to include multiple representative species and expand the current focus on PFOS and PFOA to other bioaccumulative PFAS chemicals. This evaluation enhances risk management and risk communication by identifying additional PFAS chemicals (e.g., PFHxS) that have the potential to influence ecological risk-based decision making at AFFF sites, but also helps existing site-specific evaluations more effectively and efficiently estimate PFAS ecological risks.

Most environmental conferences and workshops include some information on emerging contaminants, but the Emerging Contaminants Summit is the only one that comprehensively addresses mitigating the presence of these contaminants across all environmental media including surface water, groundwater, drinking water, wastewater, recycled water, soils and sediments.

More Information

Learn more about the event: http://www.contaminantssummit.com/
Read the event handbook: Click here to download the 2018 Emerging Contaminants Handbook
For consultation regarding Emerging Contaminants, contact Rula Deeb at This email address is being protected from spambots. You need JavaScript enabled to view it..
Learn more about Rula at: https://www.geosyntec.com/people/rula-deeb

Geosyntec Consultants
Geosyntec is a specialized consulting and engineering firm that works with private and public sector clients to address new ventures and complex problems involving our environment, natural resources, and civil infrastructure.

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