JOINT BASE PEARL HARBOR-HICKAM, Hawaii -- Recently detected low levels of total petroleum hydrocarbons, or TPH, in the Navy’s drinking water system were the result of laboratory contamination and not associated with the release of jet fuel from the Red Hill Bulk Fuel Storage Facility, the Navy Closure Task Force-Red Hill (NCTF-RH) announced April 24.
As part of the Navy’s commitment to long-term monitoring of the Joint Base Pearl Harbor-Hickam (JBPHH) drinking water system, the Task Force’s “Swarm Team” investigated the earlier findings and determined the false positives were due to the presence of chlorine, which is added to disinfect drinking water before it reaches consumers.
The results of the 8,500 samples tested during the long-term monitoring are still valid. The low-level detections were found to be inflated due to a chemical reaction during laboratory analysis and not related to TPH concentrations in the water. The details are in the full report that can be found here: Technical Memorandum
“The results of the team are now final; we’ve validated the data and we’re confident in why we've seen these low-level detections,” said Chris Waldron, Swarm Team member. “This information is helping the Navy to voluntarily refine its testing processes”.
Revised Testing Methodology
The team convened in January to determine the root cause of the low-level TPH detections after an increase in the number of detections was observed in late 2023. The team, which consisted of experts from across the Navy and Department of Defense, the Environmental Protection Agency (EPA), Hawaii Department of Health (DOH) and various contractors, met daily to review drinking water testing data. They investigated numerous potential root causes and evaluated multiple lines of evidence, ultimately concluding that challenges with the laboratory method itself were responsible for the increase in frequency of the low-level TPH detections.
To minimize the potential for cross-contamination of samples in the laboratory and to prevent chlorine from causing false positive detections of TPH, the team recommended the Navy use a different, EPA-approved method to analyze all future drinking water samples for TPH. This method -- known as Micro-Extraction with Quenching, or MEQ -- incorporates a step to reduce the effect of chlorine prior to analysis and eliminates false positive detections of TPH. The MEQ method does not change or alter the concentration of fuel-related petroleum if it is present in a sample. With this process, if petroleum is present in the sample, it will still be detected via the EPA-approved MEQ method.
Testing the New Method
To find the cause of the TPH detections, the Swarm Team recommended that the Navy collect side-by-side drinking water samples from the JBPHH drinking water system. So, from February 2024 through March 2024, nearly 600 drinking water samples from homes, schools, child development centers and other locations were collected and analyzed with the original method used during the Long-Term Monitoring Program and the recommended MEQ method. 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.
To ensure the MEQ method would still detect fuel-related petroleum, the team injected drinking water samples from JBPHH with a known concentration of jet propellant 5, also known as JP-5, at the lab and validated that the MEQ method still detected the petroleum contaminant. This process demonstrated that the MEQ method accurately and precisely detects fuel-related petroleum if it is present in drinking water.
“The MEQ method uses sodium thiosulfate to neutralize or remove chlorine so the TPH testing process is accurate,” said Waldron. “There is no approved regulatory method to test for TPH in drinking water, so EPA had directed that we use a wastewater testing method approved by the EPA. That process doesn’t account for the chlorine in drinking water and was returning results that mimicked TPH. The MEQ method fixes this.”
Click Here for an easy-to-understand fact sheet.
Resolving Uncertainty
“There is still work to do,” said Rear Adm. Marc Williams, deputy commander, NCTF-RH. “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.”
Throughout the course of the assessment, the results obtained from all samples collected indicate the water on the JBPHH water system continues to comply with all state and federal drinking water standards.
For more information about NCTF-RH, visit navyclosuretaskforce.navy.mil or download the mobile app by searching for “NCTF-Red Hill” in the Apple App store or Google Play store. For imagery, video and other digital media, please visit our DVIDS site here: https://www.dvidshub.net/unit/NCTF-RH
| Date Taken: | 04.25.2024 |
| Date Posted: | 05.03.2024 21:08 |
| Story ID: | 470289 |
| Location: | HONOLULU, HAWAII, US |
| Web Views: | 23 |
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