DOH rejects Navy’s Red Hill consolidated groundwater sampling plan due to insufficient monitoring

News Release 24-057 from Hawaii DoH, April 30, 2024

HONOLULU – The Hawaiʻi Department of Health (DOH) has disapproved the Navy’s Red Hill Consolidated Groundwater Sampling Program. The DOH ordered the Navy to implement a modified version of the program, which includes additional conditions relating to groundwater monitoring to support the Navy’s request to reduce the amount of water being discharged into Halawa Stream from 4.5 million gallons a day to 1.8 million gallons a day.

“We have worked to hold the Navy accountable to create its own plan to reduce the amount of water discharged into Hālawa Stream, while still maintaining a robust sampling program to track and stay ahead of any contaminant migration,” said Deputy Director for Environmental Health Kathleen Ho. “It’s unacceptable that the Navy would fail to produce such a plan following multiple rounds of regulatory review. That’s why we are taking the unusual step to reject the Navy’s plan and impose conditions necessary to protect public health and our environment.”

Additional conditions imposed by DOH include:

• Testing for additional analytes twice a month. The additional analytes will be used to track the possible attenuation of contaminants.
• Requiring the Navy to provide data to the DOH sooner than it proposed in its plan.
• Requiring the Navy to provide the DOH with weekly updates associated with the reduced pumping rate.
• Providing details regarding the steps the Navy will take if potential plume migration is observed.

These additional conditions are being imposed to ensure DOH receives adequate data to understand how reduced pumping may affect the movement of contaminants within the aquifer, while conserving natural resources.

The DOH first authorized the Navy to discharge treated water from the Red Hill Shaft to Hālawa Stream in January 2022 to prevent contaminants from migrating to other parts of Oʻahu’s single source aquifer. The water is taken from Red Hill shaft and filtered through a granular activated carbon treatment system prior to discharge. DOH and state partners have vigilantly monitored the Navy’s testing both before and after treatment.

Testing of the water being taken from the Red Hill shaft, i.e. pre-treatment, has not detected total petroleum hydrocarbons (TPH) for nearly six months. Subsequently, the discharged water, i.e. post-treatment, has shown no detections of TPH ensuring compliance and the health of the Hālawa Stream ecosystem under the National Pollutant Discharge Elimination System permit.

The Navy submitted a Final Report of Findings for its Red Hill Shaft Flow Optimization Study on September 19, 2023. DOH is imposing its additional monitoring and reporting requirements based on the results of the study, which indicated a continued need to carefully monitor for plume migration. DOH also continues to urge the Navy to pursue beneficial reuse for water being discharged into Hālawa Stream.

Click here to download a copy of the DOH’s letter.

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CB: Navy Groundwater Sampling Plan Is Insufficient, Hawaii Health Officials Say