Marine Corps Base Hawaii has identified an elevated bacterial level at its Wastewater Reclamation Facility, according to a news release issued Wednesday.

An investigation identified the cause as ongoing maintenance activity in the plant’s polishing pond.

The news release described the risk of direct exposure to the enterococci bacteria as “extremely low.” According to the Marines, the MCBH effluent water is generally combined with treated waters from Honolulu’s Kailua Regional Wastewater Treatment Plant, making up about 10% of the total output. The combined effluent waters are discharged about two miles offshore at 110 feet below the surface of the ocean.

On Tuesday, the MCBH facility reported an enterococci count estimated at 70,000 colony forming units per 100 milliliter, which exceeded the maximum daily discharge limit of 57,850 CFU. A stepped-up rate of water sampling will be in place until results show effluent limits are being met, according to the news release.

Previously, in September, the state Department of Health issued a warning for people to stay out of the water near the MCBH WRF’s outfall in Kailua after elevated bacteria levels were detected, starting Aug. 6.

In October, the facility reported an accidental release of treated sewage into the ocean, with enterococci levels exceeding the set permit limit. In that case, the Marine Corps said that the release occurred during an improvement project designed to modernize the wastewater facility.

In the latest incident, a Marine Corps spokesman said Wednesday he did not know what specific maintenance activities contributed to higher levels, but noted that the maintenance activity at the pond was unrelated to the modernization project, which has since been completed.