Dr. Ziqi He, Ph.D., P.E.

Will Lithium Become the Next Emerging Contaminant in the Spotlight?

Dr. Ziqi He, Ph.D., P.E., Senior Technical Consultant, Verdantas LLC

Lithium is widely used in commercial industries, including pharmaceutical drugs, industrial chemical catalysts, sanitizing agents, and increasingly as a key component of batteries with a more than 5 times of production over the past decade. However, lithium is under scrutiny as a potential contaminant in drinking water. Notably, lithium is among the 66 chemicals listed in the Federal Drinking Contaminant Candidate List 5 (CCL 5) and is the sole non-PFAS (per- and polyfluoroalkyl substances) chemical selected for the fifth Unregulated Contaminant Monitoring Rule (UCMR 5). Preliminary findings from UCMR 5 reveal that lithium is detected at levels exceeding the screening health reference level in 25% of the public water systems, which is a higher occurrence compared to PFAS compounds.    Given the widespread detections in drinking water systems, will lithium be the next emerging contaminant like PFAS in regard of regulations and actions? This presentation will examine lithium detections across different sized public water systems, geographic distribution, co-presence with PFAS, and its correlation to natural background or potential anthropogenic sources (e.g., mining, industrial point discharges). Additionally, lithium toxicity and various provisional values will be compiled, such as the health reference level of 10 micrograms per liter (ug/L) used by EPA’s CCL 5 and the screening “drinking water only” benchmark level of 60 ug/L published by USGS. These insights will help to understand its presence in drinking water system, evaluate potential impacts to public health, capture public and regulatory attention, balance its critical role in industrial use with its environmental impacts, and prepare for treatment and any other compliance.   

Ziqi (Zeke) He, Ph.D., P.E. is a senior consultant at Verdantas with over 22 years of research and consulting experience in the area of fate and transport/transformation of persistent and emerging contaminants in both natural and engineered systems.  He received his BS and MS in Civil and Municipal Engineering from Xi’an University of Architecture and Technology, and his PhD in Environmental Engineering with a minor in Geological Sciences from The Ohio State University.  He has led investigation and treatment system design for emerging contaminants (e.g., PFAS, 1,4-dioxane, MTBE) at many sites.  Dr. He has also been invited as a peer reviewer for frontier scientific journals and grant proposals, and an active member of several Interstate Technology & Regulatory Council (ITRC) project teams.