Although it will never smell like a rose, Hyperion sewage plant is working hard on cutting down odors.

After 18 years of living on the bluffs above Los Angeles’ sprawling Hyperion Sewage Treatment Plant, Gerald Bushrow says his nose just isn’t what it used to be.

“I think it has been desensitized from Hyperion,” the El Segundo resident said. “I have people come over and they say, ‘What is that smell?’ I say, ‘What smell?’ ”

It may be too late for Bushrow’s nose, but others’ could be saved thanks in part to a team of eight El Segundo residents who unwittingly put their sniffers to work to help determine which foul gases at the plant are the most offensive.

To ensure noses like Bushrow’s weren’t involved, panel applicants were first tested for their ability to smell.

“We picked the most sensitive of the people, those who can smell all the smells,” said Dick Duffee, president of Odor Science and Engineering, Inc., the Connecticut company that put together the panel.

Hyperion officials say the idea to enlist the help of a panel is just one of a number of efforts undertaken recently to identify and control the foul odors that for years have wafted from the plant and into nearby neighborhoods.

For example, two so-called “odor scrubbing” towers have been installed in the plant’s primary treatment area, and 13 others will be installed at a cost of nearly $11 million as part of the mammoth renovation project now underway. Simply put, a scrubber is a large tower where odors are captured in water and then treated with chemicals.

Also, as the waste water flows into the plant, chemicals--$5,000 worth a day--are now being added to lessen the bad smells, and some treatment tanks have been covered. Cracks in others that provided escape routes for odors have been sealed.

The most recent effort is the “smell-o-rama” conducted for the sensitive sniffers on the olfactory panel. The group’s members, who were paid for their efforts, were recruited through an employment agency. To make sure that they remained unbiased, the panelists were not told the gases they would be smelling were captured at a sewage plant, said Don Goodroe, Hyperion’s superintendent of operations.

The panelists met periodically from January through April at a local hotel, smelling various gases. They identified which of the gases that are detectable at the plant smelled the worst. And they tried to determine how much dilution of these gases would make them nose-friendly.

Essentially, the panel concluded that Hyperion still has work to do when it comes to controlling odors originating at its sludge drying area, Goodroe said, adding that they may reconvene the panel for some follow-up testing.

The results from the panel’s work, as well as results from other Odor Science studies, will be used by Hyperion to cut down on the bad odors. And judging from the complaints that the plant receives from its neighbors, the plant still has a ways to go, Goodroe conceded.

Still, plant officials say progress is being made. “We feel we can make a significant improvement and be as good a neighbor as possible,” Goodroe said, though he agreed a sewer plant won’t ever smell like a rose.

“There is no zero, there is no perfect score,” he added.

Some El Segundo residents said they have noticed a decrease in bad odors. Ruth Bixler, who has lived near the plant for 20 years, recalls that years ago the smell was so strong she would have to close her windows.

And Wesley Joe, who as environmental officer for El Segundo keeps track of the odor complaints lodged against Hyperion by residents, said he has not received any for two months.

Joe said he did not know whether favorable weather conditions, the work already done by Hyperion to control the odors, or a combination of both were responsible.

“I wouldn’t hazard to guess,” he said.