The state Health Department has issued an alert, warning of possible fecal material in waters near Honolulu’s Sand Island Wastewater Treatment Plant outfall.

The public is advised to avoid waters at Sand Island due to a discharge of wastewater with levels of enterococcus — a fecal indicator — that exceeded the daily maximum permitted level.

City officials confirmed that a sample taken Tuesday from the plant exceeded the level allowed under the state’s National Pollutant Discharge Elimination System permit.

Signs have been posted to stay out of waters around the outfall, the city said, which is about 1.7 miles from shore and 230 feet below the surface.

Officials will monitor the effluent daily and are also testing samples at five shoreline stations near the treatment plant.

The Sand Island alert emerges just after the city’s announcement that effluent at the Kailua Regional Wastewater Treatment Plant is now in compliance with permitted enterococcus levels.

Test results from effluent samples taken Monday, Tuesday, and Wednesday at the Kailua plant were within permitted levels, officials said, meaning earlier exceedances are not continuing.

The bacteria levels in Kailua samples had exceeded those limits on four different days, with the first alert from the state Health Department issued last Wednesday.

Those exceedances occurred again on samples taken over the last weekend due to sequential storm events caused by the Kona low, which officials said resulted in unusually high flows at the Kailua treatment plant.

The U.S. Environmental Protection Agency uses enterococci bacteria, which live in the intestinal tracts of warm-blooded animals, as indicators of fecal material in water and therefore, the possible presence of disease-causing pathogens that can sicken swimmers.

Separately, the state Health Department has kept a brown water advisory in place for Kailua Bay, as well as Waimea Bay and Chun’s Reef on Oahu’s North Shore due to heavy rainfalls that resulted in stormwater runoff entering coastal waters.