Under Hawaii safety limits that were in place five years ago, the levels of diesel contaminants that were detected in the Red Hill well in September would’ve raised a red flag. 

Levels of diesel-range hydrocarbons at 300 parts per billion would have been nearly double the Hawaii health department’s safety threshold.

But in 2017, the Hawaii health department increased its “environmental action level” for diesel in drinking water from 160 parts per billion to 400 parts per billion, despite objections from the Honolulu Board of Water Supply.

That change meant that several samples taken from the well in September and October, which would have exceeded the pre-2017 limit instead registered as safe.  

Total petroleum hydrocarbons, or TPH, are a family of chemicals that come from crude oil. The umbrella term is not listed on the Environmental Protection Agency’s roster of regulated contaminants, leaving states to come up with their own standards. In the absence of widely agreed-upon parameters, experts may disagree on safety limits. But the Honolulu Board of Water Supply said it wants to err on the side of caution.

The water utility is now asking the state Department of Health to reverse its decision and reinstate the old threshold. In a letter sent to DOH this week, the Board of Water Supply’s manager said the old levels were “more protective of human health, the environment and our critical drinking water resources.” 

“The BWS disagrees and has consistently raised concerns about the DOH’s rationale for the change,” Chief Engineer Ernie Lau wrote.

DOH spokeswoman Kaitlin Arita-Chang said in a statement on Thursday that a review of the drinking water safety thresholds is underway. 

The EALs are based on the “lowest of thresholds for taste and odor concerns and for toxicity and health risk,” she said. 

The prior thresholds for TPH-d were based on a taste and odor threshold for kerosene in drinking water published by the Environmental Protection Agency in 1980, she said. But a review of the source material determined the number was based on a mistranslation of work published in Polish and Russian by the Soviet Union in the 1940s, according to Arita-Chang. 

DOH looked at more recent reviews done by California to determine that Hawaii’s environmental action level should be 400 parts per billion. DOH consulted with BWS and outside experts before the change was finalized.

“DOH stands by its decision, but to be clear, EALs are under constant review based on updates to science and new information,” Arita-Chang said. 

DOH guidance states that the adequacy of the environmental action levels should be verified if drinking water sources are impacted, according to Arita-Chang.

“The situation at Red Hill seems to be a case example of the need for such a review to be carried out,” she said.

The contamination of the Navy’s water system, which sickened military families and displaced them from their homes, heightened the Board of Water Supply’s concern and underscores the need to restore the EALs to their former levels, Lau said.

In his letter, Lau also took issue with additional justifications DOH cited at the time of its decision-making. 

During that process, Lau said DOH wrongfully assumed exposures to TPH-d do not occur through inhalation or skin absorption while showering, bathing or washing dishes. 

And the studies DOH relied on to make the change in EAL should not have been used because they relate to fuel release sites on the mainland, Lau argues. TPH-d in local groundwater may travel faster than elsewhere because of Hawaii’s porous lava rock, and the Red Hill facility’s operations can more directly contaminate drinking water on Oahu than would be possible in other places, he wrote.

For those reasons, there may be less time for TPH-d to degrade before human exposure, according to Lau.

In 2017, DOH also increased its “taste and odor” threshold for TPH-d from 100 parts per billion to 500 parts per billion, another decision Lau disagrees with. In his letter, he said the studies DOH relied on to make that call contain “considerable uncertainty.” 

The Navy was alerted to the contamination of its water system last year by military families who said they smelled fuel in their water and were experiencing adverse health impacts, including skin irritation and rashes – not by water testing. 

That indicates a problem, according to Lau. 

“The Navy has reported taking hundreds of samples from its water distribution system and has generally maintained that none have indicated the presence of petroleum-related constituents at or above the DOH’s current EALs,” he wrote. 

“Despite these reported results, the water contamination crisis was discovered when Navy servicemembers and their families reported strong fuel odors emanating from the water served from their taps. Given these reports, the DOH’s current taste and odor EAL of 500 (parts per billion) is simply too high.” 

During the flushing of the Navy’s water distribution system, DOH may be using an environmental action level of 200 parts per billion to assess the sufficiency of the flushing, Lau said. While Lau said he supports that, he said a more permanent revision is needed. 

“EALs should err on the side of being conservative,” Lau said. “Recent experience shows that the existing EALs are not.”