So-called emerging contaminants (ECs) like 1,4-dioxane and per- and poly- fluorinated substances (PFAS) have been receiving much press and public attention lately. Keeping-up with related news, science and policy developments may seem like an overwhelming challenge, and to some it may be tempting to overlook ECs as a sensational “issue du jour” that will pass with the next news cycle. However, there are plenty of reasons why everyone is talking and why remediation professionals of all stripes should pay attention. Here are a few of them.
- Inconsistent and Unclear Policies & Regulations. State and federal policy makers have been unable to agree on how (or even whether) to regulate ECs. It has been almost 20 years since the USEPA promulgated or modified a Maximum Contaminant Level (MCL) for a synthetic organic contaminant under the Safe Drinking Water Act (SWDA). In the interim, the USEPA has issued unenforceable “health advisory levels” for numerous ECs (like PFAS), and many states have reacted to public pressure by establishing their own, often divergent, numerical threshold values. The resulting tangle of unclear and inconsistent policies and regulations has confused the regulated community and the general public about actual risks and legal obligations, which in turn has set the stage for controversy and conflict.
- Potential for “Re-Opening” Sites. ECs are sparking renewed interest in sites that were previously approved for “closure”. Previously approved remedies may not have considered ECs for myriad reasons: a) they were unregulated or not known to be hazardous at the time, b) standards have become more stringent, and c) suitable analytical techniques were either unavailable or unable to resolve concentrations at the levels now being regulated or considered for regulation, some of which are in the parts per trillion (ppt) range (i.e., < 0.1 µg/L). Regulators have expressed concerns that historically approved remedies should be revisited to consider ECs, to ensure that those remedies remain adequately protective.
- Business Environmental Risk. Beyond the attendant regulatory risks and uncertainties, ECs may pose new and potentially significant business environmental risks. The specter of EC-related toxic tort claims is raising questions about: a) whether and how companies should assess exposure to EC-related risks, b) whether and to what extent ECs should be considered in transactional due diligence, and c) whether EC-related risks are adequately insured and eligible for claims.
- Treatment/Remediation Challenges. By their physical and chemical nature, many ECs do not respond as favorably (or at all) to common, conventional treatment and remediation technologies. For example, 1,4-dioxane cannot be effectively removed from water via air stripping, while granular active carbon (GAC) is only mildly effective for removing 1,4-dioxane. Additionally, PFAS such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are mobile in the environment and are not known to degrade at meaningful rates by natural chemical or biological process. Treating to ppt levels also presents technical challenges and limitations.
- Prevalence. Occurrence studies by the USEPA, USGS and various state agencies have identified detectable concentrations of ECs in a significant proportion of public water supplies (PWS) and surface water bodies. For example:
- 1,4-dioxane was detected in 22% of the PWS tested from 2013 through 2015 pursuant to the USEPA’s Unregulated Contaminant Monitoring Rule (UCMR).
- PFAS have been detected in a relatively smaller proportion of PWS nationally (2%) but occur more frequently in some regions like New Jersey (detected in 67% of PWS sampled from 2006-2010; see Occurrence of Perfluorinated Chemicals in Untreated New Jersey Drinking Water Sources, NJDEP Division of Water Supply and Geoscience, April 2014).
Additionally, many ECs are not rare or unusual; they have been used extensively in manufacturing processes and consumer products and therefore may have entered the environment from a variety of potential sources.
Answered by Adam Hackenberg, PG
Adam has over 20 years of diverse experience investigating and remediating environmentally distressed sites under various state programs, CERCLA/Superfund, and RCRA. He has been recognized for teaming with clients to evaluate project drivers, define goals and objectives, and develop cost-effective exit/management strategies.