The U.S. Environmental Protection Agency said it has fined two Hawaii island businesses nearly $72,000 and required them to close their illegal, large-capacity cesspools that are in violation of the Safe Drinking Water Act.

One was located at the Wailuku Professional Plaza in Hilo, and the other at Power Self Storage in Kailua-Kona.

“Big Island companies must do their part to protect our surface water and groundwater resources from the disease-causing pollution found in large capacity cesspools,” said EPA Pacific Southwest Regional Administrator Martha Guzman in a statement. “EPA is committed to finding and closing all remaining illegal cesspools in Hawaii.”

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

Large-capacity cesspools, defined by the EPA as serving multiple residential dwellings such as townhouse complexes, or 20 or more persons per day in non-residential dwellings, such as rest areas, were banned in 2005 under the Safe Drinking Water Act.

In July 2021, EPA conducted an inspection of the Wailuku Professional Plaza, which is about 100 feet from the Wailuku River in Hilo, and found two unlawful cesspools serving the multi-tenant commercial office building.

Wailuku Professional Plaza, LLC – which owns and operates the Wailuku Professional Plaza agreed to close the illegal cesspools and pay a $43,000 penalty on May 4.

EPA inspectors also found that the Power Self Storage in Kailua-Kona has a restroom served by a large capacity cesspool. SKS Management LLC – the facility’s operator – agreed to pay a $28,780 penalty and close the illegal cesspool by Sept. 1, 2023.

Since the federal ban in 2005, more than 3,750 large-capacity cesspools in Hawaii have been closed. the EPA said. However, hundreds remain in operation.

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

Those that voluntarily disclose and proactively work to close these pollution-causing systems are offered penalty mitigation and other incentives, according to the EPA, via its online eDisclosure portal at epa.gov/compliance/epas-edisclosure.