PEARL HARBOR – Approximately 12,700 gallons of less than fully treated sewage were discharged into Mamala Bay yesterday by the Navy's Fort Kamehameha Wastewater Treatment Plant.

Electricity at the treatment plant went out at 12:16 p.m. and the plant was without power until an emergency generator began powering the treatment works about four minutes later, Navy officials said.

During the time the plant was without power, the nearly 13,000 gallons of effluent, which had been treated to the advanced secondary level, were released into ocean waters through the plant's deep water outfall without Ultraviolet (UV) disinfection, the Navy said.

UV light treatment is the last step prior to effluent discharge and is used to kill any residual bacteriological organisms that were not eliminated during the treatment process.

The partially treated effluent was discharged into Mamala Bay through a 12,500-foot-long,150-foot-deep outfall.

The Navy contacted the state Department of Health to report the incident, officials said.

It was determined that signs did not need to be posted and the undisinfected advanced secondary treated effluent would be naturally dispersed with minimal human health and environmental impacts, the Navy said.