Members of the Navy’s Rapid Response Team test tap water at an Aliamanu Military Reservation home in Honolulu on March 21, 2024. (Glenn Slaughter/U.S. Navy)
FORT SHAFTER, Hawaii — The Navy has determined that hundreds of tap water tests taken at Pearl Harbor in recent months produced false positives for low-level petroleum contamination due to the test’s chemical reaction with chlorine in the samples, the service announced Thursday.
The Navy convened a “swarm team” in January to determine the root cause of an uptick in detections of low levels of total petroleum hydrocarbons, or TPH, in water samples taken in late 2023 and early this year.
Navy officials had also fielded an increased number of complaints from residents in housing on and near Joint Base Pearl Harbor-Hickam about oily sheens in tap water.
TPH refers to hundreds of compounds found in petroleum-based products, and it can serve as an indicator of contamination.
The Navy quickly determined that the TPH did not match the type of jet fuel that had been stored at the Red Hill Bulk Fuel Storage Facility a few miles from the joint base.
A massive spill of that jet fuel in late 2021 contaminated one of the wells used by the Navy to supply water to roughly 93,000 residents of military housing on and near the joint base.
Thousands of residents were forced to temporarily relocate to area hotels as the Navy sealed off the contaminated well and flushed the entire system of petroleum contamination.
A Navy task force is in the multiyear process of permanently closing the World War II-era facility.
The swarm team consists of experts from the Navy, U.S. Environmental Protection Agency, Hawaii Department of Health and contracting firms.
The team’s “root cause” investigation concluded that “challenges with the laboratory method itself were responsible for the increase in frequency of the low-level TPH detections,” the news release states.
The team hypothesized that the low-level detections could be arising from problems with the test method itself.
To test that theory, the team asked the Navy to collect side-by-side drinking water samples from the distribution system. Almost 600 samples were collected from February through March from homes, schools, child development centers and other locations, the news release states.
For each pair of samples, one was given the routine test while the second was tested using a method called Micro-Extraction with Quenching, or MEQ.
“The MEQ method uses sodium thiosulfate to neutralize or remove chlorine so the TPH testing process is accurate,” Chris Waldron, a contractor who is a member of the team, said in the release.
“The results of the side-by-side sampling conclusively demonstrated that the MEQ method eliminated the false positive TPH detections that were reported using the original sampling method,” the news release states.
The MEQ method can specifically detect traces of JP-5, the type of jet fuel that contaminated the water system in 2021, according to the release.
The team validated that by injecting JP-5 in water samples at controlled levels, and those were detected using the MEQ method.
A change of testing method, however, does not address recent complaints about water quality by some residents.
“There is still work to do,” Rear Adm. Marc Williams, deputy commander of Navy Closure Task Force-Red Hill, said in the release.
“We are confident there is no JP-5 or fuel in the water, but we will keep testing and assessing the data to determine what is causing some of the reported smells, sheens, and health concerns residents have expressed.”
