Emission Uncertainty : Trash-to-Energy Plant Puts Commerce to Test

The 65,000 people who live or work in this industrial city are about to make California history.

When a $50-million refuse-to-energy plant starts testing this fall, Commerce will be the first community in the state to generate electricity by dumping garbage into a state-of-the-art incinerator.

It will also be the first to breathe what comes out of the smokestack.

Because those emissions are expected to include two cancer-causing gases for which no safe exposure level is certain, air pollution experts from both government and industry are poised to measure the consequences.

“We will be looking at this plant very carefully,” said James Birakos, deputy executive officer of the South Coast Air Quality Management District. Up to now, he said, “everything has been theoretical. . . . For the first time we’re going to have a real, live situation here.”

Hailed as Futuristic Solution

In the meantime, waste disposal experts and city officials are hailing the plant as the first step in a futuristic solution to the county’s solid-waste disposal problem.

At a press conference this week, Mayor James B. Dimas said the plant will safely burn up to 300 tons of trash each day--about what Commerce now dumps in a sanitary landfill. At the same time, it will produce enough energy to power 20,000 homes.

Thirty-four such plants are planned statewide, including one being built on Terminal Island for Long Beach, one in Los Angeles and several in the San Gabriel Valley. But the 10-megawatt unit jointly developed by Commerce and the Los Angeles County Sanitation Districts will be the first to operate in California. Testing starts next month and commercial service is scheduled for June.

Dimas said the project gave Commerce a bold opportunity to not only solve its own garbage problem “but to also prove a technology that is going to be the answer to waste and refuse management . . .

“It shows that we’re out there in front and we’re willing to . . . show to the public that this is the answer,” Dimas said.

Talk of Hazards Discounted

The mayor discounted any suggestion that the growing debate over plant emissions has also turned his city into a technological guinea pig.

“Let me put it this way,” Dimas said. “I live right down the street, and a lot of my constituents live right there, and if I felt for any reason that this was a health hazard to the community I would have never gone with this.”

Project Manager Michael Selna agreed that the Commerce plant is the most technologically advanced when it comes to controlling routine sources of air pollution, such as sulfur dioxide and nitrogen oxides. For that reason, he expressed confidence that emissions of dioxins and furans--known to cause cancer in laboratory animals--would also pose no significant threat to public health. He said plant operators expect those emissions to be too weak to create even one cancer per million people.

“Just standing out in the sun here today we have a risk of skin cancer greater than one in a million,” Selna said. The Commerce plant is several blocks away from the nearest neighborhood, on a six-acre site between the Santa Fe Railroad tracks and a box plant operated by Finn Industries, about half a mile west of the Santa Ana Freeway.

Tougher State Standards

Concern over the two toxic gases, usually found only in the production of certain pesticides and the burning of garbage, nevertheless prompted the state Legislature to put tougher refuse-to-energy standards in a bill that now awaits the signature of Gov. George Deukmejian. While most of the proposed standards would apply to plants larger than the one in Commerce, that unit would have to conform to any future change in dioxin or furan standards.

“We’ll modify the existing equipment if necessary,” Selna said. “This is a proven technology. We fully expect it to meet the standards.”

The refuse-to-energy process itself dates back to the 1960s, Selna said. About 69 similar plants already operate in other parts of the nation and about 200 exist in Europe and Japan. California plants, especially those in the Los Angeles basin, will differ mostly in the ways they combat air pollution.

Plant construction began in March, 1985, financed by a $44-million revenue bond and contributions from the city, the county Sanitation Districts and the state Solid Waste Management Board.

Selna said the plant uses two particular pollution control techniques that have proven effective separately, but have never been combined as they are in the Commerce unit.

Storage Pit in Building

The refuse-to-energy process begins when the plant receives garbage from any of the 52 trash haulers who have routes in Commerce. The trash will be dumped in a large storage pit in the main plant building. Then it will be scooped up by an overhead crane and dropped down a chute to a huge furnace burning at between 2,000 and 2,100 degrees Fahrenheit.

Ash from the fire, by volume about 10% of the original waste, is then drawn off and trucked away for landfill disposal.

The heat created in the process boils water in pipes lining a large boiler. The resulting steam then blows against the blades of a turbine generator to create electricity. The power is to be purchased by Southern California Edison Co.

The exhaust gases that remain in the plant are first sprayed with ammonia to neutralize most of the nitrogen oxides, then sprayed with a lime solution that lumps the sulfur dioxide and hydrochlorides into fine particles.

Finally, those particles are filtered out when the exhaust passes through a “baghouse” containing 1,200 Teflon-coated fiberglass cylinders. Officials say that what eventually leaves the smokestack will be an “invisible plume” carrying fewer toxic substances than what is emitted in any existing refuse-to-energy plant. That plume is what air quality officials will monitor most closely.

‘Elusive Contaminant’

Dioxin is “sort of a peculiar and elusive contaminant” because it occurs in only a few industrial processes, air quality official Birakos said. “We’re not really sure at this point if we can really put our finger on what causes dioxins.”

Birakos said technicians aren’t even sure how they will go about testing the Commerce facility. “A lot depends on the course and the direction of the wind,” he said. “We will take readings up and down the area.

“We have to see where the people are, how many there are and what is the potential to cause a risk.”