Hawaii joined the rest of the nation in banning the construction of new cesspools when Gov. David Ige signed new rules related to wastewater disposal on Friday.

Essentially holes in the ground that discharge untreated sewage, cesspools can contaminate groundwater, drinking water, streams and the ocean, according to the state Department of Health.

Officials say the raw sewage can degrade coral reefs, harm aquatic ecosystems and make people sick. Sewage carries pathogens that cause leptospirosis, a sometimes painful and dangerous gastrointestinal illness; hepatitis A; conjunctivitis; and salmonellosis and gastroenteritis.

“Today’s action protects public health and is a good first step toward eliminating water pollution from cesspools,” Keith Kawaoka, the Health Department’s deputy director for environmental health, said in a statement.

The rules put forward by the Health Department ban new small-capacity cesspools. The U.S. Environmental Protection Agency banned cesspools serving 20 or more people, known as gang cesspools, a decade ago. The rules also implement tax credits for property owners who convert existing cesspools into septic systems or other improved treatment units, or connect to a county sewage system.

Jodi Leong, a spokeswoman for the governor’s office, said that the rules will take effect in a couple of weeks.

Many states banned new cesspools years, or even decades, ago. For example, Rhode Island, which has the second largest number of cesspools in the country, behind Hawaii, prohibited the construction of new cesspools in 1968.

But in Hawaii, efforts to restrict cesspools have met resistance from homeowners, the real estate sector and some lawmakers. While some counties have implemented their own bans, new cesspools have continued to be permitted on Hawaii island and parts of Maui County.

About 800 new cesspools have been approved annually in Hawaii, according to the Health Department. There are about 88,400 cesspools statewide — 3-1/2 times the number in Rhode Island.

Last month, 11 state legislators from Maui and Hawaii island, including House Speaker Joseph Souki (D, Waihee-Waiehu-Wailuku), sent a letter to Ige urging him not to sign the rules.

“While the (Health Department) claims that these rule changes are necessary to protect the public health and preserve our natural resources, the arguments in that regard are weak and unsubstantiated, and in fact contradictory and contrary to current legislative intent,” according to the letter, which referenced a bill that died in the Legislature last year that would have restricted cesspools.

The lawmakers said that the cesspool rules discriminate against low-income residents. Cesspools cost about $2,000 to $3,000, while septic systems in Hawaii can range in cost from $20,000 to $30,000, according to the letter.

However, a representative for Valley Isle Pumping on Maui said that the average cost of a new septic system is $12,000 to $15,000.

The new rules signed by Ige are not as stringent as those proposed under Gov. Neil Abercrombie’s administration. Those rules, which sought to phase out the use of cesspools over the long-term, required that 19,800 cesspools located within 750 feet of a stream, ocean or other surface water, as well sources of public drinking water, be switched out within a year if the property is sold. Abercrombie didn’t sign the rules before leaving office, and that requirement was stricken from the rules signed by Ige.

About 50,000 of the state’s cesspools are located on Hawaii island, 14,000 on Kauai, 12,000 on Maui, 11,000 on Oahu and 1,400 on Molokai, according to information from the Health Department. The cesspools release about 55 million gallons of raw sewage into the ground daily.

While the new rules lack mandatory requirements to discontinue the use of existing cesspools, they do give property owners incentives to convert their wastewater systems.

The rules implement a tax credit of up to $10,000 for property owners seeking to switch out their cesspool or connect to a county sewage system. The tax credits were approved by the Legislature last year and signed into law as Act 120. To qualify, cesspools must be located within 200 feet of a shoreline, stream or wetland, or near sources of drinking water.

There is a $5 million annual cap on the tax credit, which runs through 2020. If the cap is met, taxpayers can qualify for the tax credits in subsequent years. The $5 million annual allocation for tax credits would cover 500 cesspool upgrades a year.

Anthony Aalto, chairman of the Sierra Club of Oahu said he applauds the governor for signing the new rules.

“We are the last state in the nation to ban construction of new cesspools, so it is about time,” Aalto said. “It’s not just about the idea that we need a pristine environment. The Sierra Club is about protecting the environment, but we do like to point out to folks that we can do well by doing good and our oceans are where our tourists go to swim and tourism is our biggest industry. So in cleaning up our nearshore marine environment, we are taking care of the biggest driver of our economy.”

Aalto also stressed that cesspools are a public health issue, pointing out that every year a number of beaches are temporarily closed due to runoff that can include sewage.