Kokua Line June Watanabe

Sewage plant stink not likely to end

Q: The sewage treatment plant at the end of Kaneohe Bay Drive has smelled since it opened. We have been told repeatedly that the city was working on the problem, but will we ever be able to drive by it without the stench pouring into the car?

Answer: Unfortunately, the city not only is grappling with aging sewer pipes, but with sewage treatment plants that need major overhauls as well.

That includes the Kailua Wastewater Treatment Plant on Kaneohe Bay Drive.

Relief from overpowering odors may be in the air in two months, but don't expect the smell to ever go away.

The state Department of Health is investigating problems with maintenance and malfunctions at the plant and "enforcement action is pending," Jill Stensrud, supervisor of the Clean Air Branch's Enforcement Section, said Monday.

During an annual inspection on Feb. 22, no violations were found, although complaints about excessive odors were received in December and January, she said.

Because of recent complaints, an inspector visited the plant on June 9 and 14 and found ongoing problems, including malfunctions that resulted in hydrogen sulfide levels exceeding allowable "fence line" levels, Stensrud said. Hydrogen sulfide is the "unique pollutant" emitted by wastewater treatment plants.

She declined to go into detail, but said the Health Department had issued "several warning notices" to the city and planned to send another letter regarding "efforts to prevent future odor problems associated with malfunctions or maintenance" at the plant.

However, the reality is that a sewage treatment plant will emit odors.

The hydrogen sulfide ambient air standard at the Kailua plant "was established at a level (25) to minimize the public nuisance," Stensrud said.

The problem with hydrogen sulfide "is that you can smell it a very low levels." But just because you smell it, doesn't mean there's a violation, Stensrud said.

Eric Takamura, director of the city Department of Environmental Services, acknowledged the odor problems, but said the challenge is setting priorities in the face of "hundreds of millions of dollars" worth of work that needs to be done throughout the city's sewer system.

With the focus placed on updating the Honouliuli and Sand Island plants, no improvements are planned at the Kailua plant for another 10 years.

"It's not one thing that's causing the problem, it's numerous" maintenance problems, Takamura said.

For the long term, the department will "develop a strategy and plan" for fixing overall problems; more immediately, the focus will be on repairing odor control units. But that work is expected to take two months, Takamura said.