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New toilet tech promoted as cesspool option

DOH requires cesspool phaseout by 2050 to protect drinking water

The Nano Membrane Toilet, developed by Cranfield University and championed by the Gates Foundation, will be able to treat human waste on-site without external energy or water. -- Cranfield University photo

A new self-contained, waterless toilet promoted by Microsoft billionaire Bill Gates and his Gates Foundation may be a relatively inexpensive way to address the thousands of cesspools, many located Upcountry, that state Department of Health officials have said need to be replaced with septic tanks or hooked up to sewage systems by 2050.

Sen. J. Kalani English, whose 7th Senate District includes Upcountry, East Maui, Molokai and Lanai, said the reinvented toilet is one of a number of emerging technologies to address the age-old problem of disposing human waste.

“We need to get the best technology that’s out there,” he said Friday evening. “Bill Gates put a lot of money behind this.”

A few years ago, English put forward state enabling legislation to allow counties in Hawaii to approve composting toilets, something Maui County has yet to pursue, he said.

The Health Department has recommended septic systems, but that still puts liquid in the ground, and it’s “not that much better” than a cesspool, English said.

Cranfield University graphic

The cost of converting to a septic system has been put at $20,000, but English said that cost estimate was for Oahu. On Maui, where some small, old lots would be difficult to convert, the cost would be more like $30,000 to $50,000, he said.

Some lots don’t have enough room for heavy equipment to operate, he said.

The $700 to $1,000 cost of the new Gates device would result in a huge cost savings, English said, while still addressing the environmental problem of not contaminating underground drinking water supplies or the ocean.

What lies ahead is for the U.S. Environmental Protection Agency to approve the reinvented toilet technology and for the state Health Department to agree, he said.

English noted that the enabling legislation for composting toilets allows the counties room for experimentation.

“We have to leapfrog technology,” English said. “We need to phase out cesspools.”

English, the Senate majority leader, serves on the Hawaii Cesspool Working Group.

Meanwhile, other official reaction to the Gates-promoted toilet was reserved.

State Department of Health spokeswoman Janice Okubo said last week that the department’s Wastewater Branch chief had no information on the reinvented toilet and had not evaluated how the prototype could address cesspool issues in Hawaii.

“We are always open to new technology,” said Maui County Department of Environmental Management Director Stewart Stant. However, “this technology appears to focus only on toilets.”

According to a report last week by Hawaii News Now, an official with the Surfrider Foundation and Hawaii state Rep. Chris Lee (D-Kailua, Waimanalo) attended a Gates Foundation Reinvented Toilet Expo in China earlier this month.

The toilets use chemicals to transform waste into fertilizer, according to the Gates Foundation. Gates himself maintains the waste doesn’t smell or carry diseases.

“Today, we are on the cusp of a sanitation revolution,” he said in his speech at the expo Nov. 6. “It’s no longer a question of if we can do it. It’s a question of how quickly this new category of off-grid solutions will scale. We don’t know exactly how long that will take, but we do know it can’t happen fast enough.”

Stant acknowledged that the $700 to $1,000 cost for the Gates-redesigned toilet is low, per fixture. However, “there is a cost to run the system and to dispose of the ‘fertilizer’ in the back end,” he said.

“When I think of the average household, there are other fixtures that feed into the sewage system,” he said. “There are opportunities for gray water reuse that come at a cost. These costs include a secondary plumbing system to collect the gray water, a tank to store the gray water and a subsurface irrigation system to utilize the gray water. There also needs to be a system to accept the backwash/bad water from the gray water system.”

Stant said he was reserving judgment on the new toilet technology.

“We will wait to see the results of the test project and maybe more technology that addresses the entire household sewer volume,” he said.

The issue of converting from cesspools to septic tanks was a hot topic earlier this year, especially with Upcountry residents.

In February, a Department of Health informational meeting in Kula drew 150 residents. Some angrily questioned state health officials about recent studies that identified Upcountry areas for cesspool contamination of drinking-water wells.

Upcountry has 7,400 cesspools that health officials have determined are potential threats to drinking water, and a new state law requires residents to replace cesspools with a septic tank or hook up to a sewer system by 2050.

The cost of upgrading all of the state’s 88,000 cesspools is estimated at $1.75 billion, the Health Department reported.

A Health Department water quality investigation of Upcountry found two wells with elevated nitrate levels — at Baldwin Ranch Estates and the Pukalani Golf Course. Nitrates are found in fertilizer and sewage.

The Baldwin well, located below Haliimaile Avenue, showed nitrate levels of up to 8.9 milligrams per liter. That well serves as a drinking water source for a new development. The Pukalani well had nitrate levels of up to 6.8 milligrams per liter. The well was tested because it was being evaluated as a water source for a proposed development.

The legal limit for nitrate levels is 10 milligrams per liter, but the normal concentration of nitrates in Hawaii aquifers is less than 3 milligrams per liter.

Health officials said the wells with above-normal levels of nitrates were in areas with a lot of cesspools.

Officials emphasized that the water is safe to drink, but it can be fatal for infants if levels exceed 12 milligrams per liter.

High nitrate levels threaten the ocean by accelerating algae and plankton growth.

Officials ruled out other possible sources of nitrates, including nearby livestock and former sugar and pineapple fields.

* Brian Perry can be reached at bperry@mauinews.com.

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