Senior Risk Assessor
Burns & McDonnell
Dr. Kanan Patel-Coleman has over 30 years’ experience performing health risk assessments, vapor intrusion investigations, environmental/ecological assessments and project management. Her work spans a diverse client base, including commercial/industrial facilities, military installations, government agencies, school districts, hospitals, and regulators. She participated on the first ASTM team developing national guidance for vapor intrusion investigations. She has also participated on ITRC teams developing national guidance for petroleum hydrocarbon, soil background, and PFAS assessments. She received her graduate degrees from UCLA: a master’s in public health (MPH) with emphasis in environmental health and a doctorate in environmental science and engineering (DEnv).
The LNAPL Plume Went Thisaway and the Dissolved Plume Went Thataway--Reanalysis of LNAPL Migration Alters Health Risk Assessment Approach
In geologically unconfined areas at a former petroleum refinery in Cyril, Oklahoma, LNAPL migrated southeast with shallow groundwater flow toward a perennial creek - away from the adjacent town of Cyril to the west. Offsite monitoring wells in the town had either no detected dissolved phase constituents or only low levels. For these reasons, human health contaminant exposure pathways to Cyril’s inhabitants were initially considered insignificant. However, further field studies and hydrogeologic analysis of seemingly anomalous product thickness measurements demonstrated that in confined areas, a portion of the LNAPL migrated updip beneath the confining layer, against groundwater flow and toward Cyril. With this finding, vapor intrusion of volatile constituents from the onsite LNAPL and into offsite town buildings became a potential concern and had to be further investigated. This case study demonstrates the importance of robust LNAPL conceptual site model development for health risk assessment and site remediation purposes.