A group of citizens intends to file a civil suit against Hawaii County over the discharge of sewage into a popular local harbor in Kailua-Kona.

Earthjustice, which is representing Hui Malama Honokohau — made up of Native Hawaiian cultural practitioners, fishers and recreational ocean users of Honokohau harbor — on May 24 filed a 60-day notice of intent to sue over ongoing violations of the federal Clean Water Act.

Earthjustice said the county discharges about 1.7 million gallons of treated sewage per day from its North Kona plant via groundwater into the Pacific Ocean.

The treated sewage goes into a natural disposal pit in a permeable field upslope of the harbor, according to Earthjustice. Multiple, peer-reviewed scientific studies confirm that this treated sewage enters the groundwater beneath the pit and then flows with it into nearshore ocean waters including the Honokohau Small Boat Harbor.

All of this, the notice said, is happening without a required National Pollution Discharge Elimination System permit, which would ensure the discharges meet water quality standards.

“Our community enters the waters at Honokohau Harbor every day,” said the hui’s president, Mike Nakachi, in a news release. “This is our backyard. We want the County to stop contaminating our water and nearshore reef ecosystems so it’s safe for our families to fish, gather and play along our shoreline.”

Honokohau Harbor is the base for some snorkeling and whale watching tours, and many hui members use the area to fish, swim, paddle and scuba-dive.

The hui urges the county to modify operations at its Kealakehe Wastewater Treatment Plant to comply with the Clean Water Act, which would require upgrades to reduce the amount of contaminants entering the harbor.

The plant was built in 1993, according to Earthjustice attorney Elena Bryant, and as far as she knows, has been disposing treated sewage into the pit since then.

When it was built, the plan was for a proposed municipal golf course nearby to reuse the treated wastewater for irrigation, but this golf course was never built.

The nutrient-laden wastewater contributes to invasive algal blooms, which threaten the bay’s coral reef ecosystems. Additionally, the effluent, which is not disinfected, is a likely cause of numerous staph infections for people using the harbor and surrounding waters.

The hui encourages the county to recycle the wastewater for irrigation needs instead of discharging the wastewater into the harbor.

It is also concerned that Hawaii County is proposing a pump station to bring additional sewage from North Kona to the plant, which would increase inflows to more than 3 million gallons per day.

“The law requires the County to reduce the pollution it releases into the bay to ensure this ecosystem can continue to sustain life — for both wildlife and people,” said Bryant. “As climate change and ocean acidification progress, our coral reefs are under increasing pressure. If we are going to save our reefs, we cannot delay in eliminating sources of stress that are within our control, like the County’s discharges of polluted wastewater from its Kealakehe facility.”

In 2020, Earthjustice won a landmark case against the County of Maui for discharging treated sewage into groundwater that eventually makes its way into waters at Kahekili Beach Park.

In that case the U.S. Supreme Court ruled that “point source discharges,” such as those from the Lahaina wastewater treatment plant to navigable waters through groundwater, are regulated under the Clean Water Act. Earthjustice represented the Hawaii Wildlife Fund in the case.

Hawaii County said in an email that it does not comment on pending legal matters.

“However, our administration is aware of the lawsuit and has been actively involved in conversations with the Environmental Protection Agency since assuming office in December 2020,” said the county in an email. “We have made sustainability the focal point of our tenure and have proven time and time again our commitment to protecting our aina and ensuring an island where our keiki can raise their keiki for generations.”

The notice was sent to Mayor Mitch Roth, along with the county’s directors of Public Works and Environmental Management, the state Department of Health director and the national and regional administrators of the U.S. Environmental Protection Agency.

The county has 60 days to comply with the Clean Water Act, or the hui will move forward with the suit in federal court.