The term emerging contaminants (EC) is applied to compounds and substances that, for one reason or another, are the focus of new environmental regulations or rulemaking, public health advisories and, in some cases, litigation. New regulations and an evolved understanding of contaminant toxicity and abundance are driving the need for developing innovative investigation and remediation methods, as well as strategic approaches to regulatory compliance.

Effect of New EC Rules, Regulations and Standards

New rules, regulations and standards, including health advisory standards, have forced affected industries to review their existing processes and implement costly modifications to the protocols and systems used to manage materials associated with ECs. Two of the most challenging groups of ECs are those identified in the Coal Combustion Residuals (CCR) Final Rule and per- and polyfluoroalkyl substances (PFAS).

As these ECs gain attention, affected industries face the challenge of identifying existing environmental liabilities where releases have occurred and deciding what actions are needed to achieve compliance and reduce liability. Depending on the industry and contaminants involved, identifying the most appropriate course of action can be difficult and potentially includes financial and legal implications.

Challenges to EC Remediation

Rules and regulations driving industry response to CCR and PFAS compounds will, in many cases, require soil or groundwater characterization and remediation where historical releases have impacted the environment. Some challenges of undertaking a remedial effort focused on these ECs include:

  1. Remedial action objectives, such as concentration standards, associated with affected sites may be low when compared to more common environmental contaminants. As a result, the remedial approach may be required to achieve nearly undetectable values.
  2. In some cases, there is a lack of remedial technologies to target these specific compounds.
  3. For CCR constituents, an understanding of geochemistry and potential side effects associated with groundwater remedies is critical to achieving the intended objectives.

Considering these challenges, site characterization and remedial programs must employ the most effective available technologies. Practitioners should remain well-informed of technological advancements that will yield more cost-effective and sustainable solutions. Doing so will provide opportunities to optimize or alter remedial actions to expedite progress and reduce total cost.

Preparing for Remediation

Even amid the challenges associated with the cleanup of ECs, certain steps can be taken to increase the likelihood of success and reduced financial liability. 

By focusing on project factors that will remain constant — and leveraging a refined understanding of those factors — we can identify potential compliance strategies early in the site characterization process and facilitate informed decision-making as additional information and new technologies become available. In most cases, early development of accurate and comprehensive conceptual site models focused on subsurface stratigraphy, hydrology, contaminant fate and transport mechanisms, and geochemistry will be a critical component of the site evaluation and decision-making process.

Employing emerging best practices  such as three-dimensional visualization (3DV) modeling, geochemical modeling and geospatial statistical analyses — should be considered for all EC remediation projects. While these tools will not be required for all projects, they can substantially improve technical and financial outcomes when appropriately applied.   


Effective management of the cost, risk and compliance challenges related to ECs requires project teams with the experience and technical knowledge needed to consider all project factors and interdependencies. The project team must also remain current on emerging best practices and technologies. Doing so will allow them to leverage the benefits of innovation and deliver the best possible outcome.

Brian Hoye, PG, leads the Burns & McDonnell remediation team and specializes in applying new technologies and innovative approaches to emerging contaminant, environmental site investigation and remediation projects.