The state Department of Health is asking the Navy to step up environmental monitoring and testing at its Pearl Harbor Wastewater Treatment Plant amid continued problems with releases of partial sewage.

In a news release Thursday, the Navy said that “at the Department of Health’s direction,” it is performing additional sampling at the facility and “adjacent shoreline to ensure public health and safety while the plant undergoes significant sand filter upgrades.”

According to the news release, from Oct. 12 until Tuesday approximately 1.75 million gallons of partially treated effluent bypassed the facility’s sand filtration system, which according to the Navy was approximately 6% of the 30 million total gallons of waste processed at the plant during that period.

The Navy also said that while the 1.75 million gallons bypassed the filter, all of it was still put through ultraviolet light treatment, a process used to disinfect the wastewater, and that “historically, the sand filter bypasses that still received UV treatment prior to discharge, was within permit limits. Water samples taken during previous sand filter bypasses showed enterococci levels were below permit limits.”

Enterococci is bacteria often associated with sewage. The DOH said in a statement to the Honolulu Star-Advertiser that it asked the Navy to increase sampling because of “the increasing frequency and magnitude of sand filter bypasses” at the facility.

The agency said that “in addition to the WWTP’s required (National Pollutant Discharge Elimination System) compliance sampling location and frequency, the DOH requested daily samples of wastewater to be collected at specific areas within the plant in the treatment train and at the receiving water to determine if the bypasses of the sand filters are a risk to public health and safety.”

Conditions at the plant have been a concern for the DOH and the U.S. Environmental Protection Agency for years. In 2019, officials from the DOH’s Clean Water Branch tried to inspect the plant but reported they found it in such a state of disrepair that they were unable to safely complete the inspection. They reported their findings to the EPA and Department of Defense.

After follow-up inspections, EPA and Navy inspectors found that the plant had cracked concrete tanks, warped and disconnected parts in its machinery and severely corroded equipment. The EPA concluded the plant was well exceeding its discharge limits for zinc, cadmium, oil and grease, and pH and total waste toxicity under the Federal Clean Water Act.

In June 2021 the Navy entered a Federal Facilities Compliance Agreement with the EPA that required it to make a series of repairs and upgrades to the facility by the end of 2024. But problems have persisted.

In September 2022 the DOH slapped the Navy with a notice of violation and order that included an $8.7 million fine over repeated spills and maintenance problems with the Navy’s wastewater system.

In the notice, DOH cited 766 counts of discharging pollutants into the ocean from January 2020 to July 2022; 212 counts related to operation and maintenance failures; and 17 counts of bypassing filters without authorization.

The violation order said the Navy exceeded the limit every day in 2020 as well as 276 days in 2021 and 122 days in 2022.

Discharges of partially treated wastewater have continued as the Navy and DOH work together to upgrade the plant.

The Navy said that as it works to upgrade the sand filtration system “bypasses of the sand filters could occur daily,” and that its officials are “in daily communication with the Department of Health to report bypass and sampling information.”

The Navy said it is also pursuing options to expedite completion of the sand filter upgrades as well as “alternate solutions,” and that it has contracted with “third party industry experts who are providing on-site technical assistance.”