Introduction

Groundwater Flow in the Moanalua/Red Hill/Halawa Region: Evaluating Rates, Directions, and Contamination RisksDate: March 18, 2022

Groundwater Flow in the Moanalua/Red Hill/Halawa Region: Evaluating Rates, Directions, and Contamination RisksDate: March 18, 2022

Speakers: Mr. Robert Whittier and Dr. Donald Thomas

Abstract:

The Navy stores more than 100 million gallons of petroleum-based fuels in underground storage tanks located just 100 to 150 feet above an Oahu aquifer, a primary drinking water source. Originally built in the 1940s, the Red Hill Bulk Fuel Storage Facility consists of 18 massive storage tanks and poses a contamination risk not only to the aquifer but to three other important public drinking water sources located within 2 km. Fuel leaks have occurred periodically over the decades and the Red Hill facility presents a particular contamination risk because (1) the two highest drinking water production sources are Maui-type wells (skimming tunnels) that draw water from the top of the water table, and (2) the fuels stored at the facility are characterized as “Light Non-aqueous Phase Liquids” (LNAPL) that, once released, will accumulate and spread across the top of the basal aquifer. The degree of risk of contamination to the drinking water sources is also dependent on groundwater flow trajectories and velocities beneath the tanks and surrounding areas and needs to be studied further to provide a more accurate assessment. The results of ongoing investigations around the facility will be integrated into a conceptual site model that should provide a template for continuing evaluation of contaminant risk and groundwater flow state-wide.

March 18, 2022 Transcript (download here)

March 18, 2022 Recording (click here)