[19] The AOC also required the Navy to implement a secondary containment solution (such as building a tank-within-a-tank) or empty the Red Hill facility by 2042.

"[20] The Navy operates a water system that serves approximately 93,000 people on Joint Base Pearl Harbor–Hickam and in military housing in nearby areas.

[26][27] The Hālawa Shaft is located approximately 5,000 feet (1,500 meters) from the storage tanks at the Red Hill facility.

[28][29] Beginning in the late spring of 2021 (at around the same time as the May 6 leak), residents living in military housing in the vicinity of Joint Base Pearl Harbor–Hickam began suffering from unusual medical problems, including hair falling out, fatigue, and skin rashes.

[33] The Navy's water well nearest to the Red Hill facility was found to be heavily contaminated with 140,000 parts per billion (ppb) of total petroleum hydrocarbons associated with diesel (TPH-d) and 20,000 parts per billion of total petroleum hydrocarbons associated with gasoline (TPH-g).

[43][44] The safe limits for these chemicals in drinking water are 400 parts per billion for TPH-d and 300 parts per billion for TPH-g.[43][44] Water in piping at a second Navy well was also found to be contaminated above the safe limit, with 920 parts per billion of TPH-d.[45][46] A survey jointly conducted by the DOH and the Centers for Disease Control and Prevention in January and February 2022 found that 87% of 2,289 individuals surveyed reported being sickened by fuel contamination in their water.

[47][48] 37% of those surveyed reported seeking medical care to address their symptoms, and seventeen individuals were hospitalized overnight.

[58][59][60] Decontamination of the Navy water system was declared complete on March 18, 2022, with regular testing expected to continue for at least six months afterward.

[13][67] BWS has stated that the Hālawa Shaft and the other two wells will remain shut down indefinitely due to uncertainty about the spread of the underground fuel plume.

[9][68] A monitoring well that is about 1,500 feet (460 meters) southeast of the Red Hill facility was reported to have petroleum contamination in August 2022.

[69] As the state agency responsible for regulating underground storage tanks, the DOH issued an emergency order on December 6, 2021 directing the Navy to shut down the Red Hill facility.

[84][88] In several legal cases brought under the Federal Tort Claims Act (FTCA), 7,500 people sued the Navy over the water contamination and possible resulting health effects.

[89][90][91] BWS also filed an FTCA claim against the Navy for $1.2 billion, primarily to recover the costs of establishing new water sources to replace the Hālawa Shaft and other closed wells.