KAILUA — A major malfunction at the city's Kailua Wastewater Treatment plant Saturday has officials scrambling and neighbors suffering from an odor that one woman compared to a cow pasture.

The city said a new pressurization tank blew over the weekend and it hopes a contractor will be able to repair it. In the meantime the city is taking steps to reduce odors until the equipment is fixed, said Bill Brennan, city spokesman. The plant is operational and the malfunction shouldn't interfere with sewage service, Brennan said.

"It seems repairable," he said. "We'll know better (today)."

Myrna Junk, who lives downwind of the plant located across from Aikahi Gardens, said the smell was bad all of last week but was horrific yesterday.

"It's as if you were standing in a field of cattle," Junk said. "That strong ammonia, the burn, the urine smell."

Junk said she usually doesn't catch the odors. But this new smell is offensive and if the city had warned residents she could have taken steps like closing her home and using the air conditioner to keep the smell outside, she said.

"Now we're full into allergy reactions just as I had many years ago when the plant was having odor problems," Junk said.

People have complained about odor problems at the plant since the 1990s and even after the city spent $5 million to control the problem back then, many said not much had changed. The city then said it would need to spend $3 million more to fix the problem.

The Kailua plant is a secondary treatment facility that processes sewage and wastewater from Waikane Valley to Lanikai, an area of 57 square miles.

At the beginning of the month the plant's air pressurization tank developed a hole and had to be replaced, said Marshall Lum, of the Department of Health's Wastewater Branch. The tank was brought in from Illinois, Lum said

"When the tank went down, they couldn't aerate so the sludge was turning septic; that's the reason for the odor," he said.

Reach Eloise Aguiar at eaguiar@honoluluadvertiser.com.