Ravi Arulanantham, PhD, and Nicole Gotberg, PG, (California) coauthored “Groundwater Plume Characteristics at Small Chlorinated-Solvent Release Sites in California” published in Environmental Forensics in December 2023.

Ravi and Nicole’s coauthors are Yug Rong and Mital Desai of the Los Angeles Regional Water Quality Control Board and Paul Hadley formerly of the California Department of Toxic Substances Control.

Ravi is a Senior Principal Toxicologist with over 30 years of experience in risk assessment and remediation management. He is developing California’s Low-Threat Underground Storage Tank Case Closure Policy for small petroleum hydrocarbon sites.

Nicole is a Principal Geologist with 17 years of experience focusing on hydrogeology and groundwater remediation, including expertise in the fate and transport of chlorinated solvents. She has served as an expert witness in California and is also a Placerville, California, City Council Member.

This study is the first to provide key characteristics of small chlorinated-solvent plume behaviors at California sites. These characteristics can be used to prioritize management of small chlorinated-solvent release sites, such as dry cleaners. Additionally, understanding these characteristics helps our engineers develop strategies for sustainable and environmentally sound site closure.

Environmental Forensics is an international, peer-reviewed publication offering scientific studies that explore the source, age, fate, transport, and human health and ecological effects of environmental contamination.

Abstract

There is a need to study the spatiotemporal distribution of chlorinated-solvent releases in groundwater to understand the risks and threats they pose to human health, water quality, and the environment, which then can be used to prioritize clean-up and evaluate regulatory closure with appropriate risk management controls. This paper provides a statistical analysis of spatiotemporal distribution of perchloroethylene (PCE) (and its degradation products including trichloroethene [TCE]) from 83 cases across California for which data were available on the State Water Resources Control Board’s GeoTracker database and the Department of Toxic Substance Control Board’s Envirostor database. These cases consisted of 71 dry cleaning sites and 12 other similar small solvent release sites. Statistical analyses of available groundwater data were conducted to estimate the following: maximum concentrations at the source area, groundwater plume length, plume stability; and correlations between plume length, concentrations, and plume age. At 90 percent of the sites, the PCE and TCE plume lengths were less than 1,569 feet (478 meters) and 1,782 feet (543 meters), respectively. The average plume lengths for PCE and TCE were 670 feet (204 meters) and 701 feet (213 meters), respectively. At 90 percent of the sites that have reached stable conditions, PCE and TCE concentrations at the source areas were less than 2,670 and 660 micrograms per liter respectively. This study for the first time provides key characteristics of small chlorinated-solvent plume behaviors in California that can be used to prioritize management of small chlorinated-solvent release sites and to develop strategies toward achieving closure at these sites.

More Information

Learn more about the article: Groundwater Plume Characteristics at Small Chlorinated-Solvent Release Sites in California
Learn more about: Environmental Forensics
For a consultation regarding groundwater plumes and remediation at sites with chlorinated solvents contact Ravi at rarulanantham@geosyntec.com or Nicole at ngotberg@geosyntec.com.
Learn more about Nicole: Nicole Gotberg | LinkedIn
Learn more about Ravi: Ravi Arulanantham