The U.S. Environmental Protection Agency took enforcement actions that resulted in the closure of 19 large-capacity cesspools in Hawaii last year.

Under the Safe Drinking Water Act, the EPA required the closure of all existing large-capacity cesspools by April 5, 2005, with the exception of individual cesspools connected to single-family homes. Large-capacity cesspools serve multi-unit condos, homes with a rental unit or commercial properties with 20 or more people on any day.

“We will continue working to close all remaining large cesspools,” Alexis Strauss, EPA’s acting regional administrator for the Pacific Southwest, said Wednesday in a press release. “This enforcement effort will help protect Hawaii’s drinking water and coastal water resources.”

Cesspools are underground holes used throughout Hawaii for the disposal of human waste. The raw, untreated sewage is discharged directly into the ground, according to the EPA, where it can contaminate oceans, streams and groundwater by releasing disease-causing pathogens and nitrates. They are used more widely in Hawaii than in any other state.

The EPA estimates there are approximately 90,000 remaining cesspools in Hawaii, most of which do not meet the federal criteria of large-capacity cesspools. Since EPA’s 2005 ban, however, more than 3,400 large-capacity cesspools have been closed in Hawaii, many through voluntary compliance.

The following resulted from EPA actions in 2017:

>> Matheson Tri-Gas facility, a commercial gas supply company at Campbell Industrial Park in Kapolei, closed two large-capacity cesspools and converted to a septic system. The company agreed to pay a civil penalty of $88,374 and spend an estimated $50,000 on a supplemental environmental project to close an on-site, small capacity cesspool.

>> Maui Varieties Investments Inc., which owns two Big Island hardware stores and a commercial property, is closing four large-capacity cesspools at its properties in Naalehu, Kamuela and Hilo and paid a $134,000 penalty.

>> Fileminders of Hawaii LLC, which operated a prohibited cesspool in Kapolei, and Hawaii MMGD, the company’s owner, were assessed a civil penalty of $122,000. In June, the cesspool was closed and the company installed an individual wastewater system.

>> The Navy paid a civil penalty of $94,200 and closed nine large-capacity cesspools at Joint Base Pearl Harbor-Hickam. The Navy had closed six cesspools in 2012, but had failed to close the remaining three in a timely manner. The three remaining cesspools served an estimated 160 people at three separate facilities. The Navy has since closed the noncompliant cesspools.

>>Hawaii County agreed to close seven large-capacity cesspools that serve the Pahala and Naalehu communities. The agreement requires the closure of two large-capacity cesspools serving the Pahala community, three serving the Naalehu community, and two serving the Pahala ­Elderly Apartments, which served about 280 households combined. The county agreed to replace the cesspools with wastewater treatment systems approved by the Hawaii ­Department of Health.

>> Aloha Petroleum Ltd. paid a penalty of $57,500 for the operation of a large-­capacity cesspool at its Aloha Island Mart convenience store and gas station in Captain Cook on Hawaii island. EPA found that Aloha Island Mart had operated the illegal LCC until 2014. Aloha Petroleum has since closed the noncompliant cesspool and replaced it with an approved wastewater system.

>> Uilani Associates, which owns and operates the Uilani Plaza, a multi-unit commercial building in Kamuela, paid a $6,000 fine for operating a cesspool, which it replaced with a compliant wastewater system.

More information on the large-capacity cesspool ban, including specifics of how a large-capacity cesspool is defined, is available at epa.gov/uic/cesspools-hawaii.