A former Hawaii lawmaker was sentenced Thursday to two years in prison in a federal corruption case that’s drawn attention to a perennial problem in the islands: the tens of thousands of cesspools that release 50 million gallons of raw sewage into the state’s pristine waters every day.

Cesspools — in-ground pits that collect sewage from houses and buildings not connected to city services for gradual release into the environment — are at the center of the criminal case against former Democratic state Rep. Ty Cullen. He has admitted to taking bribes of cash and gambling chips in exchange for influencing legislation to reduce Hawaii’s widespread use of cesspools.

U.S. District Court Judge Susan Oki Mollway said she gave Cullen a sentence at the shortest end of the term recommended by prosecutors because he had cooperated extensively with investigators. Yet she didn’t go as low as the 15 months requested by his defense attorney because of the serious nature of his crimes.

“This was a grievous breach of public trust on your part. It appears to have been motivated by greed, and it stretched out over a number of years,” Mollway told Cullen. “I am very concerned that this was not a momentary lapse of judgement.”

Cullen told the judge he took full responsibility for and was ashamed of his actions.

“I want to say I’m sorry to my family who stayed by me, to my friends, to my constituents, my community and the people of Hawaii,” Cullen said, choking up. “I will continue to work to make my wrongs right. And ensure that this never happens again.”

Mollway also fined Cullen $25,000.

The toxic pits proliferated in Hawaii in the ’50s, ’60s and ’70s. when investment in sewer lines didn’t keep up with rapid development. Today Hawaii has 83,000 of them — more than any other state — and only banned new cesspools in 2016.

Now Hawaii is eager to get rid of them because of the environmental damage they do and the risk of groundwater contamination.

Public spending on such efforts and the lack of knowledge about the specialized field can create conditions ripe for corruption, said Colin Moore, a political science professor at the University of Hawaii.

“That just creates a lot of opportunities because comparisons are so difficult to make, especially in a really small market like Hawaii where there may only be two, or in some cases even one, contractor who can do the work,” Moore said. “Who’s to say that the bid is inflated?”

Criminal cases related to Cullen’s have led to guilty pleas from the Honolulu businessman who bribed the lawmaker and a former Senate majority leader.

An estimated 16% of Hawaii housing units have cesspools, but the share is much higher on more rural islands like the Big Island, where more than half of the homes have them. They’re found everywhere from the mountains to the seashore and even in urban neighborhoods just miles from downtown Honolulu.

In these homes, effluence from toilets and showers flows through drains into a pit in a yard instead of into a sewer line and to a central wastewater treatment plant. Raw sewage — including all its bacteria and pathogens — then seeps from the pit into the ground, groundwater, aquifers and ocean.

The sewage can contaminate drinking water, and in the ocean it can fuel the growth of reef-smothering algae. As sea levels rise due to climate change, scientists expect the ocean to increasingly inundate cesspools on coastal properties, pushing sewage into waters where people swim.

Such concerns have prompted the Legislature to draft bills to phase out cesspools. In 2017 the state enacted a law requiring homeowners to close their cesspools and hook up to sewer systems or install cleaner on-site waste treatment systems by 2050. The most common on-site alternative is a septic tank and leach field combination, in which bacteria break down solids inside a tank and a disposal field removes wastewater and pathogens while safely returning water to the environment.

This year lawmakers are considering additional legislation, including one bill that would accelerate conversion deadlines for cesspools in more environmentally sensitive areas to 2035 and 2040. Another would establish a pilot program to expand county sewage systems.

In a plea agreement, Cullen admitted receiving envelopes of cash to help pass a bill related to cesspool conversions. He was vice chair of the powerful House Finance Committee for part of the time he received bribes.

Cullen accepted a total of $30,000 from Honolulu businessman Milton Choy, who is due to be sentenced next month. He’s also admitted accepting $22,000 in gambling chips from Choy during a trip to a New Orleans wastewater conference.

Court documents say Choy’s company regularly entered into contracts with government agencies to provide wastewater management services and was well-placed to benefit from publicly financed cesspool conversion projects.

J. Kalani English, a Democrat and the former Senate majority leader, has already been sentenced to three years and four months in prison for taking bribes from Choy, also in exchange for influencing cesspool legislation.

Prosecutors did not recommend a sentence more lenient than federal guidelines because English did not cooperate the way Cullen did, said Ken Sorenson, the assistant U.S. attorney on that case.

Separately, a former Maui County wastewater manager admitted taking $2 million from Choy in exchange for steering at least 56 sole-source contracts to his business. He was sentenced to 10 years in February.

The case has invited jests likening the unsanitary disposal pits to underhanded political behavior.

“We were joking that, ‘Oh, now these politicians have given cesspools a bad name,’” said Stuart Coleman, a longtime advocate for shutting down Hawaii’s cesspools and the executive director of the nonprofit Wastewater Alternatives and Innovations.

“It’s not too far a jump when you talk about this kind of corruption and (then) you talk about the cesspool that is politics.”