The Navy announced Wednesday in a press release that wastewater from its Joint Base Pearl Harbor-Hickam treatment plant bypassed its sand filtration step for a little over three hours the day before.

This equates to about 300,000 gallons of wastewater.

Sand filtration is one of the final steps in the plant’s wastewater treatment process, coming just before ultraviolet disinfection. It acts as the final stage of removing solids, which the press release referred to as a “polishing” stage.

According to the press release, an error from one of the preceding steps caused extra solids to enter the sand filtration system, partially clogging it. The error has since been resolved, it said.

This treatment plant made news last year when the Navy entered an agreement with the Environmental Protection Agency to make a series of repairs and major upgrades in order to comply with relevant laws like the Clean Water Act, which its discharges had been violating.

State officials first made note of the plant’s decaying infrastructure in 2019, when they were unable to complete an inspection due to its shoddy state. Officials then contacted the EPA and the Department of Defense, resulting in the agreement, which calls for the repairs to be finished by the end of 2024.

All wastewater from the treatment plant is released into Mamala Bay via a pipe that discharges it 1.5 miles out from the shore and 150 feet deep.

Except for the sand filtration step, the affected wastewater was otherwise properly filtered and disinfected, ensuring that it doesn’t violate permit limitations, according to the Navy. It added that the wastewater will “be naturally dispersed with minimal human health and environmental impacts.”