It was supposed to be a routine procedure, testing sensors for the Navy’s Red Hill fire suppressant system, but something — even days later, the Navy stated it didn’t know exactly what — went wrong.

On Tuesday, about 1,100 gallons of chemical fire suppressant was spilled, completely emptying the tank storing this environmentally toxic “forever chemical,” which does not break down.

Another hazardous spill in a Navy system related to Red Hill, and another breakdown in the interconnected Navy systems that fuel ocean-going tankers, provide water to military properties, and supposedly, ensure safety throughout the Joint Base Pearl Harbor-Hickam area.

This latest incident signals that the Navy does not have its operations locked down, and creates doubt that it is employing sufficient safeguards to prevent other dangerous developments as it prepares to drain the massive underground fuel tanks at the Red Hill Bulk Fuel Storage Facility. The defueling of some 104 million gallons has been ordered in the wake of other accidents and fuel spills that have contaminated the Navy’s own water supply, sickened hundreds and threatened the safety of Honolulu’s water system.

The fire suppressant tank that spilled the hazardous substance wasn’t included in the scrutiny applied to the accident-plagued Red Hill facility, which is undergoing necessary repairs before defueling — but it should have been. Ironically, that tank was expected to be in working order to ensure safety during the eventual draining of the massive fuel tanks, a sensitive process involving highly flammable material.

The fire suppressant, an aqueous film-forming foam (AFFF) that puts out burning liquid fuel, is made up of chemicals known as per- and polyfluoroalkyl substances, or PFAS. Once released into soil or water, they accumulate in fish, wildlife and ultimately, people, interfering with biological systems including reproduction and immune reactions.

In coordination with the Hawaii Department of Health and Environmental Protection Agency, the Navy quickly agreed to a plan to test soil and water supplies around the spill site, ensuring that cleanup has been thorough. This Sampling and Analysis Plan commits to testing nine nearby groundwater monitoring wells for PFAs. Soil at the spill site will also be tested, and approximately 3,000 cubic feet of soil is being removed from the site.

The rapid response is commendable, but comes too late to avoid the hazard, expense and delay of contamination and cleanup.

All Red Hill defueling-related work and repairs have now been suspended to focus on the spill cleanup and investigation, further delaying completion of that urgent mission.

The delay is disappointing, but the AFFF spill also raises an alarm: Extensive, effective safety scrutiny must be applied before undertaking any further operations connected to Red Hill, or exposing Oahu to further hazards.

Losing the reservoir of fire suppressant has already changed “the current risk situation,” the Navy acknowledged. The Joint Task Force-Red Hill is now appointing an investigating officer to conduct a “thorough” investigation into the spill. Fire protection at Red Hill is being managed by the base’s Federal Fire unit.

The Navy assures islanders that drinking water remains safe, as it flows from the Waiawa shaft, about 6 miles away. To keep the water safe, the Navy must redouble its efforts to establish strict working safeguards, for all its military and contractor workers, that protect against any further ground or water contamination.

This latest incident brought Honolulu’s Board of Water Supply Manager Ernie Lau to the brink of tears, as he expressed his fear for the protection of Oahu’s aquifers. Take it as a directive, Navy: Don’t make Ernie Lau, or the public, cry again.