top of page

Legacy and Emerging Contaminants



TIG Environmental’s experts are leaders in evaluating legacy and emerging contaminants in the environment. Our experts have decades of experience and knowledge discerning sources and the fate of polychlorinated biphenyls (PCBs), dioxins and furans (PCCD/Fs), polycyclic aromatic hydrocarbons (PAHs), as well as mercury and other metals in rivers, lakes, ports, harbors, groundwater, and soils. Additionally, we support clients in developing strategies and forensic methodologies related to emerging contaminants such as per- and polyfluoroalkyl substances (PFAS). We understand the unique challenges associated with the forensic evaluation of legacy and emerging contaminants and recognize the need to use an integrated approach to evaluate multiple lines of evidence. Our expertise in forensics and source identification integrates with TIG Environmental’s other areas of expertise to provide end-to-end litigation and mediation support, including: 

  • Identifying and modeling release pathways and fate transport processes 

  • Performing multivariate analysis and other forensic data analytics 

  • Identifying the presence of unique chemical markers including impurities and/or the presence of specific isomers 

  • Evaluating onsite and offsite historical operations and infrastructure 

  • Researching trade, scientific, historical, and regulatory documents to create inventories of potential contaminant sources as well as identify witnesses, unique records, and other factual evidence not uncovered through formal civil discovery 

  • Developing and evaluating evidentiary databases using commercial platforms; triaging and prioritizing content contained in incoming discovery productions using our Triage and Intelligence Gathering e-Discovery Routine (TIGER

  • Developing, managing, and vetting witness pools; tracing and evaluating complex corporate transactions; and locating evidence of potential insurance coverage

Per- and polyfluoroalkyl substances (PFAS)

Per- and polyfluoroalkyl substances (PFAS) have quickly become a primary focus of regulators and a significant liability concern for parties involved in its past or present manufacture, use, handling, or disposal. TIG Environmental is a leading investigations and forensics firm focused on minimizing our client’s financial exposure to the emerging contaminant group known as PFAS. Our unique mix of technical and investigative expertise can support you in assessing and managing your potential PFAS liabilities.

Dioxins and Furans (PCDD/F)

Dioxins and furans (PCDD/F) belong to a family of toxic substances that share a similar chemical structure. Dioxins have been found in the air, soil, sediment, and food and have been linked to human health and ecological effects. TIG Environmental has worked on some of the largest and most complex dioxin sites in the world. Our experts focus on evaluation of PCDD/F fingerprints in environmental media and knowledge of various chemical processes that can release PCDD/F into the environment. Additional lines of evidence used on the analysis of PCDD/F sources include sediment fate and transport, sediment dating, and tracking the presence of unique chemical tracers. We use these multiple lines of evidence to develop a fact-based analysis of scientific and legal claims that a facility may or may not have been a significant source of dioxins to the environment.

Mercury and other Metals

Mercury is a pollutant that globally affects human and ecosystem health. Mercury in the environment can come from anthropogenic sources (originating from human activity) and geogenic sources (originating from geological processes). Anthropogenic activity has significantly altered the bio-geochemical cycle of mercury. Our experts have decades of experience evaluating mercury sources in the environment, including wastewater discharges of mercury from chloralkali plants, mercury from mining activities, mercury food-web contamination, and mass transfer studies of mercury from upland sources to rivers and lakes. We can also use mercury isotopes for fingerprinting contaminant sources, including differentiating sources derived from atmospheric, industrial, and watershed emissions. The stable isotopic fingerprint approach is particularly effective for differentiating sources of other metals (lead, iron, copper, zinc, boron etc.).

Polychlorinated Biphenyls (PCBs)

Polychlorinated biphenyls (PCBs) belong to a family of man-made organic chemicals known as chlorinated hydrocarbons. PCBs were used in hundreds of industrial and commercial applications and do not readily break down in the environment. TIG Environmental has extensive experience evaluating sources of PCBs at contaminated sites. To determine the most likely sources of PCBs, we evaluate multiple lines of evidence, including historical process operations, potential for migration and weathering, sediment dating, fingerprints of Aroclor and PCB congeners, and results of advanced state-of-the-art multivariate statistical analysis.

Polycyclic Aromatic Hydrocarbons (PAHs)

Polycyclic aromatic hydrocarbons (PAHs) are found naturally in the environment but can also be produced from human activities (anthropogenic). The most common anthropogenic sources of contamination include incomplete combustion of oil, gas, and garbage. TIG Environmental has extensive experience evaluating potential sources of PAHs, such as manufactured gas plants (MGPs). Our analyses focus on historical evidence gathering and evaluation, differences in PAH ratios and methylation patterns to distinguish pyrogenic and/or petrogenic sources of PAH, and results of advanced state-of-the-art multivariate statistical analysis.


TIG’s expert reports and expert testimony are helping the client negotiate favorable settlements with some plaintiffs and mount a vigorous defense in court cases associated with other plaintiffs.

Alleged Dioxin Emissions from an Industrial Facility

TIG Environmental moved a multi-stakeholder project forward to completion, implementing a practical solution at a complex site. Our proposed solution was accepted by the client, the regulators, and the community.

Design and Implementation of Deep Excavation for PCB Removal

TIG Environmental’s analysis proved that polychlorinated biphenyl (PCB) releases from the client’s facilities were much lower than anticipated, resulting in a lower allocation.

Identification of Relative Contaminant Discharge Leads to Lower Allocation

TIG Environmental demonstrated that PCBs adjacent to the client's facility did not originate from the facility’s current or historical operations, but instead from the operations of upstream or adjacent facilities.

PCB Characterization and Sediment Modeling Result in More Equitable Cost Allocation

TIG Environmental's analysis is being used to support the client in obtaining a more equitable allocation of investigation, design, and remediation costs. The potential savings to the client could be in the hundreds of millions of dollars.

Complex Multi-PRP Sediment Sites

TIG Environmental was able to identify multiple chemical signatures in the sediment, providing our client with identification of PRPs that have some liability for the sediment contamination.

Forensic Studies and Modeling

TIG Environmental develops web-based solutions that integrate geographic information systems (GIS), data management, analysis, and visualization accessible to our clients.

InSight - Putting Spatial Data Visualization and Analytics in the Hands of Our Clients

TIG Environmental was able to identify multiple chemical signatures in the sediment that were consistent with specific upland operations and the insufficiency of the previous remediation of sediments, providing our client with identification of PRPs that have some liability for the sediment contamination.

PCB Forensics at a Major Superfund Site

The results of the analysis were used to narrowly define the spatial extent of AFFF impacts and limit the scope of the investigation and remediation.

Delineation of PFAS Contamination

TIG Environmental's analysis is being used to support the client in obtaining a more equitable sharing of investigation, design, and response costs. The potential savings to the client could be in the millions of dollars.

Groundwater PFAS Contamination with Multiple Sources

The Intelligence Group provided our manufacturing client with a cost-effective and robust tool for quickly assessing and monitoring risks posed by emerging contaminants in a complex and evolving regulatory landscape.

Managing Emerging Risks

Our analyses, including the development of interactive dashboards, are being used to evaluate and communicate the relevant information to counsel and develop the defense strategy.

PFAS Class Action Litigation

For more information contact:
Paul Brzozowski, PE
Paul Brzozowski, PE
Managing Director

Business Development Lead

bottom of page