Cardno TEC was contracted to characterize historic fuel releases from the Navy Red Hill Fuel Storage Facility located on Oahu, Hawaii. The facility consists of 20 underground storage tanks constructed before WWII with a total capacity of 250 million gallons. Past investigations identified fuel releases impacting groundwater quality near a drinking water well. Cardno TEC installed monitoring wells and developed a 3D groundwater model to evaluate fuel transport. Their risk assessments found no imminent threat to water supply. They established long-term groundwater and soil vapor monitoring programs and a groundwater protection plan implemented since 2004.