The U.S. Environmental Protection Agency has fined the owner and operator of a Hawaii island storage facility $130,000 for operating an illegal cesspool.

The EPA has also ordered Kaloko Storage 18 LLC and Extra Space Management Inc., the respective owner and operator of Extra Space Storage at Kanalani Street in Kailua-Kona, to close its large-capacity cesspool to comply with the Safe Drinking Water Act.

“Illegal large capacity cesspools pose major threats to groundwater and precious coastal resources across Hawaii,” said EPA Pacific Southwest Regional Administrator Martha Guzman in a news release. “EPA is committed to using our enforcement authority to ensure that all such unlawful cesspools are permanently closed to protect the public health of residents and their vital water resources.”

Cesspools — basically underground holes for the disposal of human waste — discharge untreated raw sewage into the ground, where disease-causing pathogens and harmful chemicals can contaminate groundwater, streams and the ocean.

The EPA defines large-capacity cesspools as those serving multiple residential units such as apartment buildings or 20 or more persons per day in a commercial building or public rest area.

EPA inspected the Extra Space Storage facility in July 2021, confirming there was one large-capacity cesspool in operation at the site.

As part of a settlement, the New York-based owner and Utah-based operator agreed to backfill the cesspool in December 2022 and pay the $130,000 fine.

Since 2005, more than 3,750 large-capacity cesspools in Hawaii have been closed, including those operated by financial institutions such as American Savings Bank as well as those owned by the state. However, hundreds remain in operation.

Cesspools are used more widely in Hawaii than in any other U.S. state, according to the EPA, and pose a unique challenge given that groundwater provides 95% of all local water supply for the islands.

Incentives are available to those who voluntarily disclose and close their cesspools.